Showing papers in "Cancer Prevention Research in 2016"

Targeting Inflammation in Cancer Prevention and Therapy

Abstract: Inflammation is associated with the development and malignant progression of most cancers. As most of the cell types involved in cancer-associated inflammation are genetically stable and thus are not subjected to rapid emergence of drug resistance, the targeting of inflammation represents an attractive strategy both for cancer prevention and for cancer therapy. Tumor-extrinsic inflammation is caused by many factors, including bacterial and viral infections, autoimmune diseases, obesity, tobacco smoking, asbestos exposure, and excessive alcohol consumption, all of which increase cancer risk and stimulate malignant progression. In contrast, cancer-intrinsic or cancer-elicited inflammation can be triggered by cancer-initiating mutations and can contribute to malignant progression through the recruitment and activation of inflammatory cells. Both extrinsic and intrinsic inflammation can result in immunosuppression, thereby providing a preferred background for tumor development. In clinical trials, lifestyle modifications including healthy diet, exercise, alcohol, and smoking cessation have proven effective in ameliorating inflammation and reducing the risk of cancer-related deaths. In addition, consumption of certain anti-inflammatory drugs, including aspirin, can significantly reduce cancer risk, suggesting that common nonsteroidal anti-inflammatory drugs (NSAID) and more specific COX2 inhibitors can be used in cancer prevention. In addition to being examined for their preventative potential, both NSAIDs and more potent anti-inflammatory antibody-based drugs need to be tested for their ability to augment the efficacy of more conventional therapeutic approaches on the basis of tumor resection, radiation, and cytotoxic chemicals. Cancer Prev Res; 9(12); 895-905. ©2016 AACR.

Transforming Cancer Prevention through Precision Medicine and Immune-oncology

Abstract: We have entered a transformative period in cancer prevention (including early detection). Remarkable progress in precision medicine and immune-oncology, driven by extraordinary recent advances in genome-wide sequencing, big-data analytics, blood-based technologies, and deep understanding of the tumor immune microenvironment (TME), has provided unprecedented possibilities to study the biology of premalignancy. The pace of research and discovery in precision medicine and immunoprevention has been astonishing and includes the following clinical firsts reported in 2015: driver mutations detected in circulating cell-free DNA in patients with premalignant lesions (lung); clonal hematopoiesis shown to be a premalignant state; molecular selection in chemoprevention randomized controlled trial (RCT; oral); striking efficacy in RCT of combination chemoprevention targeting signaling pathway alterations mechanistically linked to germline mutation (duodenum); molecular markers for early detection validated for lung cancer and showing promise for pancreatic, liver, and ovarian cancer. Identification of HPV as the essential cause of a major global cancer burden, including HPV16 as the single driver of an epidemic of oropharyngeal cancer in men, provides unique opportunities for the dissemination and implementation of public health interventions. Important to immunoprevention beyond viral vaccines, genetic drivers of premalignant progression were associated with increasing immunosuppressive TME; and Kras vaccine efficacy in pancreas genetically engineered mouse (GEM) model required an inhibitory adjuvant (Treg depletion). In addition to developing new (e.g., epigenetic) TME regulators, recent mechanistic studies of repurposed drugs (aspirin, metformin, and tamoxifen) have identified potent immune activity. Just as precision medicine and immune-oncology are revolutionizing cancer therapy, these approaches are transforming cancer prevention. Here, we set out a brief agenda for the immediate future of cancer prevention research (including a "Pre-Cancer Genome Atlas" or "PCGA"), which will involve the inter-related fields of precision medicine and immunoprevention - pivotal elements of a broader domain of personalized public health.

Risk prediction models for colorectal cancer: a systematic review

Abstract: Colorectal cancer is the second leading cause of cancer-related death in Europe and the United States. Survival is strongly related to stage at diagnosis and population-based screening reduces colorectal cancer incidence and mortality. Stratifying the population by risk offers the potential to improve the efficiency of screening. In this systematic review we searched Medline, EMBASE, and the Cochrane Library for primary research studies reporting or validating models to predict future risk of primary colorectal cancer for asymptomatic individuals. A total of 12,808 papers were identified from the literature search and nine through citation searching. Fifty-two risk models were included. Where reported (n = 37), half the models had acceptable-to-good discrimination (the area under the receiver operating characteristic curve, AUROC >0.7) in the derivation sample. Calibration was less commonly assessed (n = 21), but overall acceptable. In external validation studies, 10 models showed acceptable discrimination (AUROC 0.71-0.78). These include two with only three variables (age, gender, and BMI; age, gender, and family history of colorectal cancer). A small number of prediction models developed from case-control studies of genetic biomarkers also show some promise but require further external validation using population-based samples. Further research should focus on the feasibility and impact of incorporating such models into stratified screening programmes.

Colorectal Cancer and Dysplasia in Inflammatory Bowel Disease: A Review of Disease Epidemiology, Pathophysiology, and Management

Abstract: Crohn disease and ulcerative colitis are chronic inflammatory bowel diseases (IBD) characterized by recurrent episodes of mucosal inflammation. This chronic mucosal inflammation has several potential consequences, one of which is the occurrence of colitis-associated colorectal cancer. Over the past decade, our understanding of the epidemiology, pathophysiology, and overall approach to diagnosing and managing colitis-associated colorectal cancer has grown considerably. In the current review article, we outline these advancements and highlight areas in need of further research. Cancer Prev Res; 9(12); 887-94. ©2016 AACR.

Cervical Microbiota Associated with Higher Grade Cervical Intraepithelial Neoplasia in Women Infected with High-Risk Human Papillomaviruses

Abstract: It is increasingly recognized that microbes that reside in and on human body sites play major roles in modifying the pathogenesis of several diseases, including cancer. However, specific microbes or microbial communities that can be mechanistically linked to cervical carcinogenesis remain largely unexplored. The purpose of the study was to examine the association between cervical microbiota and high-grade cervical intraepithelial neoplasia (CIN 2+) in women infected with high-risk (HR) human papillomaviruses (HPV) and to assess whether the cervical microbiota are associated with oxidative DNA damage as indicated by the presence of cervical cells positive for 8-hydroxy-2'-deoxyguanosine. The study included 340 women diagnosed with CIN 2+ (cases) and 90 diagnosed with CIN 1 (non-cases). Microbiota composition was determined by Illumina sequencing of the 16S rRNA gene amplified from DNA extracted from cervical mucus samples. Measures of alpha/beta-diversity were not associated with either CIN severity or oxidative DNA damage. However, a cervical mucosal community type (CT) dominated by L. iners and unclassified Lactobacillus spp was associated with CIN 2+ (OR = 3.48; 95% CI, 1.27-9.55). Sequence reads mapping to Lactobacillaceae, Lactobacillus, L. reuteri, and several sub-genus level Lactobacillus operational taxonomic units were also associated with CIN 2+ when examined independently (effect size >2.0; P < 0.05). Our 16S rRNA sequencing results need confirmation in independent studies using whole-genome shotgun sequencing and that would allow sharpening the suggested associations at finer taxonomic levels. Our results provide little evidence that DNA oxidative damage mediates the effect of the microbiome on the natural history of HPV infection and CIN severity. Cancer Prev Res; 9(5); 357-66. ©2016 AACR.

DNA Hypomethylation Contributes to Genomic Instability and Intestinal Cancer Initiation

Abstract: Intestinal cancer is a heterogeneous disease driven by genetic mutations and epigenetic changes. Approximately 80% of sporadic colorectal cancers are initiated by mutation and inactivation of the adenomatous polyposis coli (APC) gene, which results in unrestrained intestinal epithelial growth and formation of adenomas. Aberrant DNA methylation promotes cancer progression by the inactivation of tumor suppressor genes via promoter methylation. In addition, global DNA hypomethylation is often seen before the formation of adenomas, suggesting that it contributes to neoplastic transformation. Previous studies employed mice with a hypomorphic mutation in DNA methyltransferase 1 (Dnmt1), which exhibited constitutive global DNA hypomethylation and decreased tumorigenesis in the Apc(Min/+) mouse model of intestinal cancer. However, the consequences of intestinal epithelial-specific acute hypomethylation during Apc(Min/+) tumor initiation have not been reported. Using temporally controlled intestinal epithelial-specific gene ablation, we show that total loss of Dnmt1 in the Apc(Min/+) mouse model of intestinal cancer causes accelerated adenoma initiation. Deletion of Dnmt1 precipitates an acute response characterized by hypomethylation of repetitive elements and genomic instability, which surprisingly is followed by remethylation with time. Two months post-Dnmt1 ablation, mice display increased macroadenoma load, consistent with a role for Dnmt1 and DNA methylation in maintaining genomic stability. These data suggest that DNA hypomethylation plays a previously unappreciated role in intestinal adenoma initiation. Cancer Prev Res; 9(7); 534-46. ©2016 AACRSee related article by Lee and Laird, p. 509.

The Case for a Pre-Cancer Genome Atlas (PCGA)

Abstract: Understanding the earliest molecular and cellular events associated with cancer initiation remains a key bottleneck to transforming our approach to cancer prevention and detection. While TCGA has provided unprecedented insights into the genomic events associated with advanced stage cancer, there have been few studies comprehensively profiling premalignant and early-stage disease or elucidating the role of the microenvironment in premalignancy and tumor initiation. In this article, we make a call for development of a "Pre-Cancer Genome Atlas (PCGA)," a concerted initiative to characterize the molecular alterations in premalignant lesions and the corresponding changes in the microenvironment associated with progression to invasive carcinoma. This initiative will require a multicenter coordinated effort to comprehensively profile (cellular and molecular) premalignant lesions and their corresponding "field of injury" collected longitudinally as the lesion progresses towards or regresses from frank malignancy across multiple tumor types. Genomic characterization of alterations in premalignant lesions and their microenvironment, for both bulk tissue and single cells, will enable development of biomarkers for early detection and risk stratification as well as allow for the development of novel targeted cancer interception strategies. The multi-institutional and multidisciplinary collaborative "big-data" effort underlying the PCGA will help usher in a new era of precision medicine for cancer detection and prevention.

Whole-genome sequencing of salivary gland adenoid cystic carcinoma

Abstract: Adenoid cystic carcinomas (ACC) of the salivary glands are challenging to understand, treat, and cure. To better understand the genetic alterations underlying the pathogenesis of these tumors, we performed comprehensive genome analyses of 25 fresh-frozen tumors, including whole-genome sequencing and expression and pathway analyses. In addition to the well-described MYB-NFIB fusion that was found in 11 tumors (44%), we observed five different rearrangements involving the NFIB transcription factor gene in seven tumors (28%). Taken together, NFIB translocations occurred in 15 of 25 samples (60%, 95% CI, 41%-77%). In addition, mRNA expression analysis of 17 tumors revealed overexpression of NFIB in ACC tumors compared with normal tissues (P = 0.002). There was no difference in NFIB mRNA expression in tumors with NFIB fusions compared with those without. We also report somatic mutations of genes involved in the axonal guidance and Rho family signaling pathways. Finally, we confirm previously described alterations in genes related to chromatin regulation and Notch signaling. Our findings suggest a separate role for NFIB in ACC oncogenesis and highlight important signaling pathways for future functional characterization and potential therapeutic targeting.

Early Events in the Molecular Pathogenesis of Lung Cancer

Abstract: The majority of cancer-related deaths in the United States and worldwide are attributed to lung cancer. There are more than 90 million smokers in the United States who represent a significant population at elevated risk for lung malignancy. In other epithelial tumors, it has been shown that if neoplastic lesions can be detected and treated at their intraepithelial stage, patient prognosis is significantly improved. Thus, new strategies to detect and treat lung preinvasive lesions are urgently needed in order to decrease the overwhelming public health burden of lung cancer. Limiting these advances is a poor knowledge of the earliest events that underlie lung cancer development and that would constitute markers and targets for early detection and prevention. This review summarizes the state of knowledge of human lung cancer pathogenesis and the molecular pathology of premalignant lung lesions, with a focus on the molecular premalignant field that associates with lung cancer development. Lastly, we highlight new approaches and models to study genome-wide alterations in human lung premalignancy in order to facilitate the discovery of new markers for early detection and prevention of this fatal disease. Cancer Prev Res; 9(7); 518-27. ©2016 AACR.

Prevention of Carcinogen-Induced Oral Cancer by Sulforaphane

Abstract: Chronic exposure to carcinogens represents the major risk factor for head and neck squamous cell carcinoma (HNSCC). Beverages derived from broccoli sprout extracts (BSE) that are rich in glucoraphanin and its bioactive metabolite sulforaphane promote detoxication of airborne pollutants in humans. Herein, we investigated the potential chemopreventive activity of sulforaphane using in vitro models of normal and malignant mucosal epithelial cells and an in vivo model of murine oral cancer resulting from the carcinogen 4-nitroquinoline-1-oxide (4NQO). Sulforaphane treatment of Het-1A, a normal mucosal epithelial cell line, and 4 HNSCC cell lines led to dose- and time-dependent induction of NRF2 and the NRF2 target genes NQO1 and GCLC, known mediators of carcinogen detoxication. Sulforaphane also promoted NRF2-independent dephosphorylation/inactivation of pSTAT3, a key oncogenic factor in HNSCC. Compared with vehicle, sulforaphane significantly reduced the incidence and size of 4NQO-induced tongue tumors in mice. A pilot clinical trial in 10 healthy volunteers evaluated the bioavailability and pharmacodynamic activity of three different BSE regimens, based upon urinary sulforaphane metabolites and NQO1 transcripts in buccal scrapings, respectively. Ingestion of sulforaphane-rich BSE demonstrated the greatest, most consistent bioavailability. Mucosal bioactivity, defined as 2-fold or greater upregulation of NQO1 mRNA, was observed in 6 of 9 evaluable participants ingesting glucoraphanin-rich BSE; 3 of 6 ingesting sulforaphane-rich BSE; and 3 of 9 after topical-only exposure to sulforaphane-rich BSE. Together, our findings demonstrate preclinical chemopreventive activity of sulforaphane against carcinogen-induced oral cancer, and support further mechanistic and clinical investigation of sulforaphane as a chemopreventive agent against tobacco-related HNSCC. Cancer Prev Res; 9(7); 547-57. ©2016 AACR.

Inflammation-Related IL1β/IL1R Signaling Promotes the Development of Asbestos-Induced Malignant Mesothelioma

Abstract: Exposure to asbestos is causally associated with the development of malignant mesothelioma, a cancer of cells lining the internal body cavities. Malignant mesothelioma is an aggressive cancer resistant to all current therapies. Once inhaled or ingested, asbestos causes inflammation in and around tissues that come in contact with these carcinogenic fibers. Recent studies suggest that inflammation is a major contributing factor in the development of many types of cancer, including malignant mesothelioma. The NALP3/NLRP3 inflammasome, including the component ASC, is thought to be an important mediator of inflammation in cells that sense extracellular insults, such as asbestos, and activate a signaling cascade resulting in release of mature IL1β and recruitment of inflammatory cells. To determine if inflammasome-mediated inflammation contributes to asbestos-induced malignant mesothelioma, we chronically exposed Asc-deficient mice and wild-type littermates to asbestos and evaluated differences in tumor incidence and latency. The Asc-deficient mice showed significantly delayed tumor onset and reduced malignant mesothelioma incidence compared with wild-type animals. We also tested whether inflammation-related release of IL1β contributes to tumor development in an accelerated mouse model of asbestos-induced malignant mesothelioma. Nf2(+/-);Cdkn2a(+/-) mice exposed to asbestos in the presence of anakinra, an IL1 receptor (IL1R) antagonist, showed a marked delay in the median time of malignant mesothelioma onset compared with similarly exposed mice given vehicle control (33.1 weeks vs. 22.6 weeks, respectively). Collectively, these studies provide evidence for a link between inflammation-related IL1β/IL1R signaling and the development of asbestos-induced malignant mesothelioma. Furthermore, these findings provide rationale for chemoprevention strategies targeting IL1β/IL1R signaling in high-risk, asbestos-exposed populations. Cancer Prev Res; 9(5); 406-14. ©2016 AACR.

Genomic Landscape of Colorectal Mucosa and Adenomas

Abstract: The molecular basis of the adenoma-to-carcinoma transition has been deduced using comparative analysis of genetic alterations observed through the sequential steps of intestinal carcinogenesis. However, comprehensive genomic analyses of adenomas and at-risk mucosa are still lacking. Therefore, our aim was to characterize the genomic landscape of colonic at-risk mucosa and adenomas. We analyzed the mutation profile and copy number changes of 25 adenomas and adjacent mucosa from 12 familial adenomatous polyposis patients using whole-exome sequencing and validated allelic imbalances (AI) in 37 adenomas using SNP arrays. We assessed for evidence of clonality and performed estimations on the proportions of driver and passenger mutations using a systems biology approach. Adenomas had lower mutational rates than did colorectal cancers and showed recurrent alterations in known cancer driver genes (APC, KRAS, FBXW7, TCF7L2) and AIs in chromosomes 5, 7, and 13. Moreover, 80% of adenomas had somatic alterations in WNT pathway genes. Adenomas displayed evidence of multiclonality similar to stage I carcinomas. Strong correlations between mutational rate and patient age were observed in at-risk mucosa and adenomas. Our data indicate that at least 23% of somatic mutations are present in at-risk mucosa prior to adenoma initiation. The genomic profiles of at-risk mucosa and adenomas illustrate the evolution from normal tissue to carcinoma via greater resolution of molecular changes at the inflection point of premalignant lesions. Furthermore, substantial genomic variation exists in at-risk mucosa before adenoma formation, and deregulation of the WNT pathway is required to foster carcinogenesis. Cancer Prev Res; 9(6); 417-27. ©2016 AACR.

Clinical Trial of 2-Phenethyl Isothiocyanate as an Inhibitor of Metabolic Activation of a Tobacco-Specific Lung Carcinogen in Cigarette Smokers

Abstract: 2-Phenethyl isothiocyanate (PEITC), a natural product found as a conjugate in watercress and other cruciferous vegetables, is an inhibitor of the metabolic activation and lung carcinogenicity of the tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in F344 rats and A/J mice. We carried out a clinical trial to determine whether PEITC also inhibits the metabolic activation of NNK in smokers. Cigarette smokers were recruited and asked to smoke cigarettes containing deuterium-labeled [pyridine-D4]NNK for an acclimation period of at least 1 week. Then subjects were randomly assigned to one of two arms: PEITC followed by placebo, or placebo followed by PEITC. During the 1-week treatment period, each subject took PEITC (10 mg in 1 mL of olive oil, 4 times per day). There was a 1-week washout period between the PEITC and placebo periods. The NNK metabolic activation ratio [pyridine-D4]hydroxy acid/total [pyridine-D4]NNAL was measured in urine samples to test the hypothesis that PEITC treatment modified NNK metabolism. Eighty-two smokers completed the study and were included in the analysis. Overall, the NNK metabolic activation ratio was reduced by 7.7% with PEITC treatment (P = 0.023). The results of this trial, while modest in effect size, provide a basis for further investigation of PEITC as an inhibitor of lung carcinogenesis by NNK in smokers. Cancer Prev Res; 9(5); 396-405. ©2016 AACR.

Diallyl Disulfide (DADS), a Constituent of Garlic, Inactivates NF-κB and Prevents Colitis-Induced Colorectal Cancer by Inhibiting GSK-3β

Abstract: There is a strong belief that garlic has medicinal properties and may even reduce the risk of developing certain cancers including those of the gastrointestinal tract. The chemopreventive effects of garlic may be attributed to the anti-inflammatory properties of the sulfur-containing constituents of garlic, which includes diallyl disulfide (DADS). Here, we demonstrate that DADS prevented colorectal tumorigenesis in a mouse model of colitis-induced colorectal cancer. Supplementation with 85 ppm of DADS (60 mg daily human equivalent dose) in the diet of FVB/N mice treated with chemical carcinogen azoxymethane (AOM) and colonic irritant dextran sodium sulfate (DSS) resulted in the reduction in tumor incidence, tumor number, and tumor burden by 21.54%, 47.3%, and 66.4%, respectively. Further analysis revealed that mice fed the DADS-supplemented diet resolved the initial DSS-induced inflammation faster than those on the control diet, preventing prolonged inflammation and cellular transformation. Subsequent mechanistic studies in vitro suggest that DADS chemopreventive effects are mediated through NF-κB signaling. When SW480 colorectal cancer cells were treated with DADS, NF-κB nuclear localization and activity were diminished. Interestingly, NF-κB suppression was found to be dependent on DADS inhibition of GSK-3β, a positive regulator of NF-κB. Inhibition of GSK-3β and loss of nuclear NF-κB activity were also observed in vivo in AOM/DSS-treated mice fed a diet supplemented with 85 ppm DADS. Our results indicate that DADS can prevent tumorigenesis by suppressing inflammation, a process largely involving GSK-3β inhibition and consequential reduction in NF-κB nuclear localization. Cancer Prev Res; 9(7); 607-15. ©2016 AACR.

A Randomized Double-Blind Placebo-Controlled Phase IIB Trial of Curcumin in Oral Leukoplakia.

Abstract: Oral leukoplakia is a potentially malignant lesion of the oral cavity, for which no effective treatment is available. We investigated the effectiveness of curcumin, a potent inhibitor of NF-κB/COX-2, molecules perturbed in oral carcinogenesis, to treat leukoplakia. Subjects with oral leukoplakia (n = 223) were randomized (1:1 ratio) to receive orally, either 3.6 g/day of curcumin (n = 111) or placebo (n = 112), for 6 months. The primary endpoint was clinical response obtained by bi-dimensional measurement of leukoplakia size at recruitment and 6 months. Histologic response, combined clinical and histologic response, durability and effect of long-term therapy for an additional six months in partial responders, safety and compliance were the secondary endpoints. Clinical response was observed in 75 (67.5%) subjects [95% confidence interval (CI), 58.4-75.6] in the curcumin and 62 (55.3%; 95% CI, 46.1-64.2) in placebo arm (P = 0.03). This response was durable, with 16 of the 18 (88.9%; 95% CI, 67.2-96.9) subjects with complete response in curcumin and 7 of 8 subjects (87.5%) in placebo arm, demonstrating no relapse after 6 months follow-up. Difference in histologic response between curcumin and placebo was not significant (HR, 0.88, 95% CI, 0.45-1.71; P = 0.71). Combined clinical and histologic response assessment indicated a significantly better response with curcumin (HR, 0.50; 95% CI, 0.27-0.92; P = 0.02). Continued therapy, in subjects with partial response at 6 months, did not yield additional benefit. The treatment did not raise any safety concerns. Treatment of oral leukoplakia with curcumin (3.6 g for six months), thus was well tolerated and demonstrated significant and durable clinical response for 6 months. Cancer Prev Res; 9(8); 683-91. ©2016 AACR.

Isorhapontigenin (ISO) Inhibits Invasive Bladder Cancer Formation In Vivo and Human Bladder Cancer Invasion In Vitro by Targeting STAT1/FOXO1 Axis.

Abstract: Although our most recent studies have identified Isorhapontigenin (ISO), a novel derivative of stilbene that isolated from a Chinese herb Gnetum cleistostachyum, for its inhibition of human bladder cancer growth, nothing is known whether ISO possesses an inhibitory effect on bladder cancer invasion. Thus, we addressed this important question in current study and discovered that ISO treatment could inhibit mouse-invasive bladder cancer development following bladder carcinogen N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) exposure in vivo We also found that ISO suppressed human bladder cancer cell invasion accompanied by upregulation of the forkhead box class O 1 (FOXO1) mRNA transcription in vitro Accordingly, FOXO1 was profoundly downregulated in human bladder cancer tissues and was negatively correlated with bladder cancer invasion. Forced expression of FOXO1 specifically suppressed high-grade human bladder cancer cell invasion, whereas knockdown of FOXO1 promoted noninvasive bladder cancer cells becoming invasive bladder cancer cells. Moreover, knockout of FOXO1 significantly increased bladder cancer cell invasion and abolished the ISO inhibition of invasion in human bladder cancer cells. Further studies showed that the inhibition of Signal transducer and activator of transcription 1 (STAT1) phosphorylation at Tyr701 was crucial for ISO upregulation of FOXO1 transcription. Furthermore, this study revealed that metalloproteinase-2 (MMP-2) was a FOXO1 downstream effector, which was also supported by data obtained from mouse model of ISO inhibition BBN-induced mouse-invasive bladder cancer formation. These findings not only provide a novel insight into the understanding of mechanism of bladder cancer's propensity to invasion, but also identify a new role and mechanisms underlying the natural compound ISO that specifically suppresses such bladder cancer invasion through targeting the STAT1-FOXO1-MMP-2 axis. Cancer Prev Res; 9(7); 567-80. ©2016 AACR.

Analysis of Immune Cells from Human Mammary Ductal Epithelial Organoids Reveals Vδ2+ T Cells That Efficiently Target Breast Carcinoma Cells in the Presence of Bisphosphonate

Abstract: Developing strategies to enhance cancer prevention is a paramount goal, particularly given recent concerns about surgical treatment of preinvasive states such as ductal carcinoma in situ. Promoting effective immunosurveillance by leukocytes that scan for nascent neoplastic transformations represents a potential means to achieve this goal. Because most breast cancers arise within the ductal epithelium, enhancing protective immunosurveillance will likely necessitate targeting one or more of the distinctive lymphocyte types found in these sites under normal conditions. Here, we have characterized the intraepithelial lymphocyte compartment of non-cancerous human breast tissue and identified a subset of T lymphocytes that can be pharmacologically targeted to enhance their responses to breast cancer cells. Specifically, Vδ2(+) γδ T cells were consistently present in preparations of mammary ductal epithelial organoids and they proliferated in response to zoledronic acid, an aminobisphosphonate drug. Vδ2(+) T cells from breast ductal organoids produced the antitumor cytokine IFNγ and efficiently killed bisphosphonate-pulsed breast carcinoma cells. These findings demonstrate the potential for exploiting the ability of Vδ2(+) γδ T cells to respond to FDA-approved bisphosphonate drugs as a novel immunotherapeutic approach to inhibit the outgrowth of breast cancers.

Suppression of Proinflammatory and Prosurvival Biomarkers in Oral Cancer Patients Consuming a Black Raspberry Phytochemical-Rich Troche

Abstract: Black raspberries (BRB) demonstrate potent inhibition of aerodigestive tract carcinogenesis in animal models. However, translational clinical trials evaluating the ability of BRB phytochemicals to impact molecular biomarkers in the oral mucosa remain limited. The present phase 0 study addresses a fundamental question for oral cancer food-based prevention: Do BRB phytochemicals successfully reach the targeted oral tissues and reduce proinflammatory and antiapoptotic gene expression profiles? Patients with biopsy-confirmed oral squamous cell carcinomas (OSCC) administered oral troches containing freeze-dried BRB powder from the time of enrollment to the date of curative intent surgery (13.9 ± 1.27 days). Transcriptional biomarkers were evaluated in patient-matched OSCCs and noninvolved high at-risk mucosa (HARM) for BRB-associated changes. Significant expression differences between baseline OSCC and HARM tissues were confirmed using a panel of genes commonly deregulated during oral carcinogenesis. Following BRB troche administration, the expression of prosurvival genes (AURKA, BIRC5, EGFR) and proinflammatory genes (NFKB1, PTGS2) were significantly reduced. There were no BRB-associated grade 3-4 toxicities or adverse events, and 79.2% (N = 30) of patients successfully completed the study with high levels of compliance (97.2%). The BRB phytochemicals cyanidin-3-rutinoside and cyanidin-3-xylosylrutinoside were detected in all OSCC tissues analyzed, demonstrating that bioactive components were successfully reaching targeted OSCC tissues. We confirmed that hallmark antiapoptotic and proinflammatory molecular biomarkers were overexpressed in OSCCs and that their gene expression was significantly reduced following BRB troche administration. As these molecular biomarkers are fundamental to oral carcinogenesis and are modifiable, they may represent emerging biomarkers of molecular efficacy for BRB-mediated oral cancer chemoprevention.

American Ginseng Attenuates Colitis Associated Colon Carcinogenesis in Mice: Impact on Gut Microbiota and Metabolomics

Abstract: Inflammatory bowel disease is a risk factor for colorectal cancer initiation and development. In this study, the effects of American ginseng on chemically induced colitis and colon carcinogenesis were evaluated using an azoxymethane (AOM)/dextran sulfate sodium (DSS) mouse model. During the acute phase on day 15, the oral administration of ginseng (15 and 30 mg/kg/day) significantly suppressed AOM/DSS-induced colitis, as demonstrated by the disease activity index and colon tissue histology. During the chronic phase in week 13, AOM/DSS-induced tumor multiplicity was significantly suppressed by ginseng. Ginseng significantly attenuated the increase of inflammatory cytokines, such as IL1α, IL1β, IL6, G-CSF, and GM-CSF. Serum metabolomics data in the PCA plots showed good separation between the AOM/DSS model and ginseng-treated mice, and the most important endogenous metabolite changes were identified. The 16S rRNA data showed that after AOM/DSS, the microbiome community in the model group was obviously changed, and ginseng inhibited these changes. Fecal metabolomics analysis supported these findings. In conclusion, oral ginseng significantly decreased AOM/DSS-induced colitis and colon carcinogenesis by inhibiting inflammatory cytokines and restoring the metabolomics and microbiota profiles accordingly. Selective endogenous small molecules could be used as biomarkers to elucidate the effects of ginseng treatment. Cancer Prev Res; 9(10); 803-11. ©2016 AACR.

The Doylestown Algorithm: A Test to Improve the Performance of AFP in the Detection of Hepatocellular Carcinoma

Abstract: Biomarkers for the early diagnosis of hepatocellular carcinoma (HCC) are needed to decrease mortality from this cancer. However, as new biomarkers have been slow to be brought to clinical practice, we have developed a diagnostic algorithm that utilizes commonly used clinical measurements in those at risk of developing HCC. Briefly, as α-fetoprotein (AFP) is routinely used, an algorithm that incorporated AFP values along with four other clinical factors was developed. Discovery analysis was performed on electronic data from patients who had liver disease (cirrhosis) alone or HCC in the background of cirrhosis. The discovery set consisted of 360 patients from two independent locations. A logistic regression algorithm was developed that incorporated log-transformed AFP values with age, gender, alkaline phosphatase, and alanine aminotransferase levels. We define this as the Doylestown algorithm. In the discovery set, the Doylestown algorithm improved the overall performance of AFP by 10%. In subsequent external validation in over 2,700 patients from three independent sites, the Doylestown algorithm improved detection of HCC as compared with AFP alone by 4% to 20%. In addition, at a fixed specificity of 95%, the Doylestown algorithm improved the detection of HCC as compared with AFP alone by 2% to 20%. In conclusion, the Doylestown algorithm consolidates clinical laboratory values, with age and gender, which are each individually associated with HCC risk, into a single value that can be used for HCC risk assessment. As such, it should be applicable and useful to the medical community that manages those at risk for developing HCC.

Effects of Walnut Consumption on Colon Carcinogenesis and Microbial Community Structure

Abstract: Walnuts are composed of a complex array of biologically active constituents with individual cancer-protective properties. Here, we assessed the potential benefit of whole walnut consumption in a mouse tumor bioassay using azoxymethane. In study 1, a modest reduction (1.3-fold) in tumor numbers was observed in mice fed a standard diet (AIN-76A) containing 9.4% walnuts (15% of total fat). In study 2, the effects of walnut supplementation was tested in the Total Western Diet (TWD). There was a significant reduction (2.3-fold; P < 0.02) in tumor numbers in male mice fed TWD containing 7% walnuts (10.5% of total fat). Higher concentrations of walnuts lacked inhibitory effects, particularly in female mice, indicating there may be optimal levels of dietary walnut intake for cancer prevention. Since components of the Mediterranean diet have been shown to affect the gut microbiome, the effects of walnuts were therefore tested in fecal samples using 16S rRNA gene sequencing. Carcinogen treatment reduced the diversity and richness of the gut microbiome, especially in male mice, which exhibited lower variability and greater sensitivity to environmental changes. Analysis of individual operational taxonomic units (OTU) identified specific groups of bacteria associated with carcinogen exposure, walnut consumption, and/or both variables. Correlation analysis also identified specific OTU clades that were strongly associated with the presence and number of tumors. Taken together, our results indicate that walnuts afford partial protection to the colon against a potent carcinogenic insult, and this may be due, in part, to walnut-induced changes to the gut microbiome. Cancer Prev Res; 9(8); 692-703. ©2016 AACR.

Obesity-Associated Alterations in Inflammation, Epigenetics, and Mammary Tumor Growth Persist in Formerly Obese Mice.

Abstract: Using a murine model of basal-like breast cancer, we tested the hypothesis that chronic obesity, an established breast cancer risk and progression factor in women, induces mammary gland epigenetic reprogramming and increases mammary tumor growth. Moreover, we assessed whether the obesity-induced epigenetic and protumor effects are reversed by weight normalization. Ovariectomized female C57BL/6 mice were fed a control diet or diet-induced obesity (DIO) regimen for 17 weeks, resulting in a normal weight or obese phenotype, respectively. Mice on the DIO regimen were then randomized to continue the DIO diet or were switched to the control diet, resulting in formerly obese (FOb) mice with weights comparable with control mice. At week 24, all mice were orthotopically injected with MMTV-Wnt-1 mouse mammary tumor cells. Mean tumor volume, serum IL6 levels, expression of proinflammatory genes in the mammary fat pad, and mammary DNA methylation profiles were similar in DIO and FOb mice and higher than in controls. Many of the genes found to have obesity-associated hypermethylation in mice were also found to be hypermethylated in the normal breast tissue of obese versus nonobese human subjects, and nearly all of these concordant genes remained hypermethylated after significant weight loss in the FOb mice. Our findings suggest that weight normalization may not be sufficient to reverse the effects of chronic obesity on epigenetic reprogramming and inflammatory signals in the microenvironment that are associated with breast cancer progression. Cancer Prev Res; 9(5); 339-48. ©2016 AACR.

Piperlongumine Suppresses Growth and Sensitizes Pancreatic Tumors to Gemcitabine in a Xenograft Mouse Model by Modulating the NF-kappa B Pathway

Abstract: Pancreatic cancer is an aggressive malignancy, which generally respond poorly to chemotherapy. Hence, novel agents that are safe and effective are highly needed. The aim of this study was to investigate whether piperlongumine, a natural product isolated from the fruit of the pepper Piper longum, has any efficacy against human pancreatic cancer when used either alone or in combination with gemcitabine in vitro and in a xenograft mouse model. In vitro, piperlongumine inhibited the proliferation of pancreatic cancer cell lines, potentiated the apoptotic effects of gemcitabine, inhibited the constitutive and inducible activation of NF-κB, and suppressed the NF-κB-regulated expression of c-Myc, cyclin D1, Bcl-2, Bcl-xL, Survivin, XIAP, VEGF, and matrix metalloproteinase-9 (MMP-9). Furthermore, in an in vivo xenograft model, we found piperlongumine alone significantly suppressed tumor growth and enhanced the antitumor properties of gemcitabine. These results were consistent with the downregulation of NF-κB activity and its target genes, decreased proliferation (PCNA and Ki-67), decreased microvessel density (CD31), and increased apoptosis (TUNEL) in tumor remnants. Collectively, our results suggest that piperlongumine alone exhibits significant antitumor effects against human pancreatic cancer and it further enhances the therapeutic effects of gemcitabine, possibly through the modulation of NF-κB- and NF-κB-regulated gene products.

Serum Antibodies to HPV16 Early Proteins Warrant Investigation as Potential Biomarkers for Risk Stratification and Recurrence of HPV-Associated Oropharyngeal Cancer

Abstract: Human papillomavirus (HPV) is responsible for increasing incidence of oropharyngeal cancer. At present, there are no biomarkers in the surveillance algorithm for HPV-positive oropharyngeal cancer (HPV-OPC). HPV16 E6 antibody precedes oropharyngeal cancer diagnosis. If HPV16 E6 indeed precedes primary diagnosis, it is similarly expected to precede disease recurrence and may have a potential role as a biomarker for surveillance of HPV-OPC. To determine whether HPV antibody titers have a potential role as early markers of disease recurrence or prognosis, a retrospective pilot study was designed to determine whether HPV16 early antibody titers E6, E7, E1, and E2 decrease after treatment of HPV16-positive OPC. Trends in pretreatment, early (≤6 months after treatment), and late posttreatment (>6 months after treatment) HPV16 antibody titers were examined. There were 43, 34, and 52 subjects with serum samples available for pretreatment, early, and late posttreatment intervals. Mean pretreatment antibody levels were higher than posttreatment antibody levels. Average antibody levels decreased significantly over time for E6 (Ptrend = 0.001) and E7 (Ptrend < 0.001). Six disease recurrences were observed during the follow-up period (median, 4.4 years). In univariate analysis, a log-unit increase in pretreatment E6 titer was significantly associated with increased risk of disease recurrence (HR, 5.42; 95% CI, 1.1-25.7; P = 0.03). Therefore, levels of antibodies to HPV16 early oncoproteins decline after therapy. Higher E6 titers at diagnosis are associated with significant increases in the risk of recurrence. These data support the prospective evaluation of HPV16 antibodies as markers of surveillance and for risk stratification at diagnosis.

Relationship of terminal duct lobular unit involution of the breast with area and volume mammographic densities

Abstract: Elevated mammographic density (MD) is an established breast cancer risk factor. Reduced involution of terminal duct lobular units (TDLU), the histologic source of most breast cancers, has been associated with higher MD and breast cancer risk. We investigated relationships of TDLU involution with area and volumetric MD, measured throughout the breast and surrounding biopsy targets (perilesional). Three measures inversely related to TDLU involution (TDLU count/mm(2), median TDLU span, median acini count/TDLU) assessed in benign diagnostic biopsies from 348 women, ages 40-65, were related to MD area (quantified with thresholding software) and volume (assessed with a density phantom) by analysis of covariance, stratified by menopausal status and adjusted for confounders. Among premenopausal women, TDLU count was directly associated with percent perilesional MD (P trend = 0.03), but not with absolute dense area/volume. Greater TDLU span was associated with elevated percent dense area/volume (P trend<0.05) and absolute perilesional MD (P = 0.003). Acini count was directly associated with absolute perilesional MD (P = 0.02). Greater TDLU involution (all metrics) was associated with increased nondense area/volume (P trend ≤ 0.04). Among postmenopausal women, TDLU measures were not significantly associated with MD. Among premenopausal women, reduced TDLU involution was associated with higher area and volumetric MD, particularly in perilesional parenchyma. Data indicating that TDLU involution and MD are correlated markers of breast cancer risk suggest that associations of MD with breast cancer may partly reflect amounts of at-risk epithelium. If confirmed, these results could suggest a prevention paradigm based on enhancing TDLU involution and monitoring efficacy by assessing MD reduction.

β-Cryptoxanthin Reduced Lung Tumor Multiplicity and Inhibited Lung Cancer Cell Motility by Downregulating Nicotinic Acetylcholine Receptor α7 Signaling

Abstract: Despite the consistent association between a higher intake of the provitamin A carotenoid β-cryptoxanthin (BCX) and a lower risk of lung cancer among smokers, potential mechanisms supporting BCX as a chemopreventive agent are needed. We first examined the effects of BCX on 4-[methyl nitrosamino]-1-[3-pyridyl]-1-butanone (NNK)-induced lung tumorigenesis in A/J mice. BCX supplementation was given daily to the mice starting 2 weeks prior to the injection of NNK and continued 16 weeks after NNK injection. BCX supplementation resulted in a dose-dependent increase of BCX concentration in both serum and lungs of the mice without a significant alteration of vitamin A (retinol and retinyl palmitate) concentration. BCX significantly reduced the multiplicity of the NNK-induced lung tumor by 52% to 63% compared with the NNK-treated mice without BCX supplementation. The protective effect of BCX in the lungs was associated with reductions of both mRNA and protein of the homopentameric neuronal nicotinic acetylcholine receptor α7 (α7-nAChR), which has been implicated in lung tumorigenesis. We then conducted an in vitro cell culture study and found that BCX treatment suppressed α7-nAChR expression and inhibited the migration and invasion of α7-nAChR-positive lung cancer cells but not in cells lacking α7-nAChR. The activities of BCX were significantly attenuated by activators of α7-nAChR/PI3K signaling or by overexpression of constitutively active PI3K. Collectively, the results suggest that BCX inhibits lung tumorigenesis and cancer cell motility through the downregulation of α7-nAChR/PI3K signaling, independent of its provitamin A activity. Therefore, BCX can be used as a chemopreventive agent or a chemotherapeutic compound against lung cancer. Cancer Prev Res; 9(11); 875-86. ©2016 AACR.

Circulating Osteopontin and Prediction of Hepatocellular Carcinoma Development in a Large European Population

Abstract: We previously identified osteopontin (OPN) as a promising marker for the early detection of hepatocellular carcinoma (HCC). In this study, we investigated the association between prediagnostic circulating OPN levels and HCC incidence in a large population-based cohort. A nested case-control study was conducted within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. During a mean follow-up of 4.8 years, 100 HCC cases were identified. Each case was matched to two controls and OPN levels were measured in baseline plasma samples. Viral hepatitis, liver function, and α-fetoprotein (AFP) tests were also conducted. Conditional logistic regression models were used to calculate multivariable odds ratio (OR) and 95% confidence intervals (95% CI) for OPN levels in relation to HCC. Receiver operating characteristics curves were constructed to determine the discriminatory accuracy of OPN alone or in combination with other liver biomarkers in the prediction of HCC. OPN levels were positively associated with HCC risk (per 10% increment, ORmultivariable = 1.30; 95% CI, 1.14-1.48). The association was stronger among cases diagnosed within 2 years of follow-up. Adding liver function tests to OPN improved the discriminatory performance for subjects who developed HCC (AUC = 0.86). For cases diagnosed within 2 years, the combination of OPN and AFP was best able to predict HCC risk (AUC = 0.88). The best predictive model for HCC in this low-risk population is OPN in combination with liver function tests. Within 2 years of diagnosis, the combination of OPN and AFP best predicted HCC development, suggesting that measuring OPN and AFP could identify high-risk groups independently of a liver disease diagnosis. Cancer Prev Res; 9(9); 758-65. ©2016 AACR.

Gene Signature in Sessile Serrated Polyps Identifies Colon Cancer Subtype

Abstract: Sessile serrated colon adenoma/polyps (SSA/P) are found during routine screening colonoscopy and may account for 20% to 30% of colon cancers. However, differentiating SSA/Ps from hyperplastic polyps (HP) with little risk of cancer is challenging and complementary molecular markers are needed. In addition, the molecular mechanisms of colon cancer development from SSA/Ps are poorly understood. RNA sequencing (RNA-Seq) was performed on 21 SSA/Ps, 10 HPs, 10 adenomas, 21 uninvolved colon, and 20 control colon specimens. Differential expression and leave-one-out cross-validation methods were used to define a unique gene signature of SSA/Ps. Our SSA/P gene signature was evaluated in colon cancer RNA-Seq data from The Cancer Genome Atlas (TCGA) to identify a subtype of colon cancers that may develop from SSA/Ps. A total of 1,422 differentially expressed genes were found in SSA/Ps relative to controls. Serrated polyposis syndrome (n = 12) and sporadic SSA/Ps (n = 9) exhibited almost complete (96%) gene overlap. A 51-gene panel in SSA/P showed similar expression in a subset of TCGA colon cancers with high microsatellite instability. A smaller 7-gene panel showed high sensitivity and specificity in identifying BRAF-mutant, CpG island methylator phenotype high, and MLH1-silenced colon cancers. We describe a unique gene signature in SSA/Ps that identifies a subset of colon cancers likely to develop through the serrated pathway. These gene panels may be utilized for improved differentiation of SSA/Ps from HPs and provide insights into novel molecular pathways altered in colon cancer arising from the serrated pathway. Cancer Prev Res; 9(6); 456-65. ©2016 AACR.

Premalignancy in Prostate Cancer: Rethinking What We Know

Abstract: High-grade prostatic intraepithelial neoplasia (PIN) has been accepted as the main precursor lesion to invasive adenocarcinoma of the prostate, and this is likely to be the case. However, in an unknown number of cases, lesions fulfilling the diagnostic criteria for high-grade PIN may actually represent intra-acinar or intraductal spread of invasive carcinoma. Intriguingly, this possibility would not contradict many of the findings of previous epidemiologic studies linking high-grade PIN to carcinoma or molecular pathologic studies showing similar genomic (e.g., TMPRSS2-ERG gene fusion) as well as epigenomic and molecular phenotypic alterations between high-grade PIN and carcinoma. Also, this possibility would be consistent with previous anatomic studies in prostate specimens linking high-grade PIN and carcinoma in autopsy and other whole prostate specimens. In addition, if some cases meeting morphologic criteria for PIN actually represent intra-acinar spread of invasive carcinoma, this could be an important potential confounder of the interpretation of past clinical trials enrolling patients presumed to be without carcinoma, who are at high risk of invasive carcinoma. Thus, in order to reduce possible bias in future study/trial designs, novel molecular pathology approaches are needed to decipher when an apparent PIN lesion may be intra-acinar/intra-ductal spread of an invasive cancer and when it truly represents a precursor state. Similar approaches are needed for lesions known as intraductal carcinoma to facilitate better classification of them as true intra-ductal/acinar spread on one hand or as precursor high-grade PIN (cribriform type) on the other hand; a number of such molecular approaches (e.g., coevaluating TMPRSS-ERG fusion and PTEN loss) are already showing excellent promise. Cancer Prev Res; 9(8); 648-56. ©2016 AACR.

Inhibition of the biosynthesis of prostaglandin E2 by low dose aspirin: implications for adenocarcinoma metastasis.

Abstract: Meta-analyses have demonstrated that low-dose aspirin reduces the risk of developing adenocarcinoma metastasis, and when colon cancer is detected during aspirin treatment, there is a remarkable 83% reduction in risk of metastasis. As platelets participate in the metastatic process, the antiplatelet action of low-dose aspirin likely contributes to its antimetastatic effect. Cycloxooxygenase-2 (COX-2)-derived prostaglandin E2 (PGE2) also contributes to metastasis, and we addressed the hypothesis that low-dose aspirin also inhibits PGE2 biosynthesis. We show that low-dose aspirin inhibits systemic PGE2 biosynthesis by 45% in healthy volunteers (P < 0.0001). Aspirin is found to be more potent in colon adenocarcinoma cells than in the platelet, and in lung adenocarcinoma cells, its inhibition is equivalent to that in the platelet. Inhibition of COX by aspirin in colon cancer cells is in the context of the metastasis of colon cancer primarily to the liver, the organ exposed to the same high concentrations of aspirin as the platelet. We find that the interaction of activated platelets with lung adenocarcinoma cells upregulates COX-2 expression and PGE2 biosynthesis, and inhibition of platelet COX-1 by aspirin inhibits PGE2 production by the platelet-tumor cell aggregates. In conclusion, low-dose aspirin has a significant effect on extraplatelet cyclooxygenase and potently inhibits COX-2 in lung and colon adenocarcinoma cells. This supports a hypothesis that the remarkable prevention of metastasis from adenocarcinomas, and particularly from colon adenocarcinomas, by low-dose aspirin results from its effect on platelet COX-1 combined with inhibition of PGE2 biosynthesis in metastasizing tumor cells. Cancer Prev Res; 9(11); 855-65. ©2016 AACR.