Showing papers in "Tumor Biology in 2013"

Long noncoding RNA: an emerging paradigm of cancer research

Abstract: Recent studies have demonstrated the importance of non-protein coding part of human genome in carcinogenesis and metastasis. Among numerous kinds of non-protein coding RNAs, long noncoding RNAs (lncRNAs) play a key regulatory role in cancer biology. LncRNAs are dysregulated in different kinds of cancer and the expression levels of certain lncRNAs are associated with recurrence, metastasis, and prognosis of cancer. It is also proved that overexpression of certain lncRNAs, behaving like oncogenes, can promote matrix invasion of cancer cells and tumor growth. In this review, we focus our attention on lncRNAs those have been validated in human cancer tissues to suggest reasonable strategies for future research. We introduce an update view of lncRNA, extract cancer-related lncRNAs from literature, and describe the known functions and possible underlying molecular mechanisms of some well investigated lncRNAs (MALAT1, HOX antisense intergenic RNA, and highly upregulated in hepatocellular cancer), as well as their current and potential future application in cancer diagnosis (PCA3) and treatment (H19).

Matrix metalloproteinases in cancer: their value as diagnostic and prognostic markers and therapeutic targets

Abstract: Biomarkers are used as tools in cancer diagnostics and in treatment stratification. In most cancers, there are increased levels of one or several members of the matrix metalloproteinases (MMPs). This is a family of proteolytic enzymes that are involved in many phases of cancer progression, including angiogenesis, invasiveness, and metastasis. It has therefore been expected that MMPs could serve as both diagnostic and prognostic markers in cancer patients, but despite a huge number of studies, it has been difficult to establish MMPs as cancer biomarkers. In the present paper, we assess some of the challenges associated with MMP research as well as putative reasons for the conflicting data on the value of these enzymes as diagnostic and prognostic markers in cancer patients. We also review the prognostic value of a number of MMPs in patients with lung, colorectal, breast, and prostate cancers. The review also discusses MMPs as potential target molecules for therapeutic agents and new strategies for development of such drugs.

Serum miR-21 and miR-92a as biomarkers in the diagnosis and prognosis of colorectal cancer.

Abstract: Previous studies from our laboratory identified a number of miRNAs that were aberrantly expressed in colorectal cancer (CRC) tissue. However, their diagnostic and prognostic value in serum has not been fully evaluated. In the present study, we measured the levels of five miRNAs (miR-21, miR-31, miR-92a, miR-18a, and miR-106a) in serum samples from 200 CRC patients, 50 advanced adenoma patients, and 80 healthy controls by real-time quantitative polymerase chain reaction (RT-PCR). In our study, the levels of miR-21 and miR-92a in patients with CRC and advanced adenoma were significantly higher than those in healthy controls (all P < 0.05). MiR-21 yielded an area under the receiver-operating characteristics (ROC) curve (AUC) of 0.802 and miR-92a yielded an AUC of 0.786 in discriminating CRCs from the controls. Additionally, miR-21 and miR-92a yielded an AUC of 0.709 and 0.701, respectively, in discriminating advanced adenomas from the controls. Combined ROC analyses using both miRNAs, revealed an elevated AUC of 0.847 in discriminating CRCs, and an AUC of 0.722 in discriminating advanced adenomas from the controls. In the multivariate Cox proportional hazards analysis, high miR-92a expression in CRC was independently associated with poor survival (P = 0.03; hazard ratio 4.36; 95 % confidence interval = 1.64–11.57). No significant difference was observed in the levels of miR-18a, miR-31, and miR-106a among CRC, advanced adenoma, and control samples. In summary, our data indicate that miR-21 and miR-92a serum levels have potential value for early detection of CRC. Furthermore, miR-92a has prognostic value in CRC patients.

The role of gut microbiota in the pathogenesis of colorectal cancer

Abstract: The human gastrointestinal tract harbors a complex and abundant microbial community that can reach levels as high as 1013–1014 microorganisms in the colon. These microorganisms are essential to a host’s well-being in terms of nutrition and mucosa immunity. However, numerous studies have also implicated members of the colonic microbiota in the development of colorectal cancer (CRC). While CRC involves a genetic component where damaged DNA and genetic instability initiates a malignant transformation, environmental factors can also contribute to the onset of CRC. Furthermore, considering the constant exposure of the colonic mucosa to the microbiome and/or its metabolites, the mucosa has long been proposed to contribute to colon tumorigenesis. However, the mechanistic details of these associations remain unknown. Fortunately, due to technical and conceptual advances, progress in characterizing the taxonomic composition, metabolic capacity, and immunomodulatory activity of human gut microbiota have been made, thereby elucidating its role in human health and disease. Furthermore, the use of experimental animal models and clinical/epidemiological studies of environmental etiological factors has identified a correlation between gut microbiota composition and gastrointestinal cancers. Bacteria continuously stimulate activated immunity in the gut mucosa and also contribute to the metabolism of bile and food components. However, the highest levels of carcinogen production are also associated with gut anaerobic bacteria and can be lowered with live lactobacilli supplements. In this review, evidence regarding the relationship between microbiota and the development of CRC will be discussed, as well as the role for microbial manipulation in affecting disease development.

Twist: a molecular target in cancer therapeutics.

Abstract: Twist, the basic helix-loop-helix transcription factor, is involved in the process of epithelial to mesenchymal transitions (EMTs), which play an essential role in cancer metastasis. Overexpression of Twist or its promoter methylation is a common scenario in metastatic carcinomas. Twist is activated by a variety of signal transduction pathways, including Akt, signal transducer and activator of transcription 3, mitogen-activated protein kinase, Ras, and Wnt signaling. Activated Twist upregulates N-cadherin and downregulates E-cadherin, which are the hallmarks of EMT. Moreover, Twist plays an important role in some physiological processes involved in metastasis, like angiogenesis, invadopodia, extravasation, and chromosomal instability. Twist also protects cancer cells from apoptotic cell death. In addition, Twist is responsible for the stemness of cancer cells and the generation of drug resistance. Recently, targeting Twist has gained significant interests in cancer therapeutics. The inactivation of Twist by small RNA technology or chemotherapeutic approach has been proved successful. Moreover, several inhibitors which are antagonistic to the upstream or downstream molecules of Twist signaling pathways have also been identified. Development of potential treatment strategies by targeting Twist has a great promise in cancer therapeutics.

The level of circulating miRNA-10b and miRNA-373 in detecting lymph node metastasis of breast cancer: potential biomarkers

Abstract: MicroRNAs (miRNAs) are a class of small noncoding RNAs whose expression changes are associated with cancer development and invasion. We hypothesized that miR-10b and miR-373, which are increased in lymphatic metastatic tissues, could be directly assayed in the plasma and used to detect the lymph node status of breast cancer patients. Between November 2009 and January 2012, 35 breast ductal carcinoma patients with lymph node metastasis (N patients), 25 ductal carcinoma patients without lymph node metastasis (N0 patients), and ten healthy female donors were enrolled in the study. Circulating miR-10b and miR-373 were determined in preoperative plasma samples by reverse transcription quantitative real-time PCR assay. In preliminary tests, the plasma levels of circulating miR-10b and miR-373 were found to be significantly higher in ten breast cancer patients with lymph node metastasis compared to ten N0 patients and ten normal donors (P < 0.01). On validation analysis, the median value level of miR-10b in the 35 N patients was 4.44-fold (P < 0.01) increased, and miR-373 was 4.38-fold (P < 0.01) increased in comparison to the 25 N0 patients. MiR-10b was used for differentiation of N patients from N0 patients; the odds ratio was 2.19, and the value of the area under the receiver-operating curve (AUC) was 0.80, with sensitivity of 71 % and specificity of 72 %. For miR-373, the odds ratio was 2.62, and the AUC was 0.84, with sensitivity of 68 % and specificity of 89 %. A combination of the two circulating miRNAs further enhanced the sensitivity to 72 % and the specificity to 94.3 %. Our data suggest that circulating miRNA-10b and miRNA-373 are potential biomarkers for detecting the lymph node status of breast cancer.

Lactate dehydrogenase A is overexpressed in pancreatic cancer and promotes the growth of pancreatic cancer cells

Abstract: The prognosis for pancreatic cancer is very poor, and developing new therapeutic strategies for this cancer is needed. Recently, the Warburg effect (aerobic glycolysis) has attracted much attention for its function in the tumorigenesis. Lactate dehydrogenase A (LDHA) executes the final step of aerobic glycolysis and has been reported to be involved in the tumor progression. However, the function of LDHA in pancreatic cancer has not been studied. Here, we found that the expression of LDHA was elevated in the clinical pancreatic cancer samples. Forced expression of LDHA promoted the growth of pancreatic cancer cells, while knocking down the expression of LDHA inhibited cell growth dramatically. Moreover, silencing the expression of LDHA inhibited the tumorigenicity of pancreatic cancer cells in vivo. Mechanistically, knocking down the expression of LDHA activated apoptosis pathway. Taken together, our study revealed the oncogenic role of LDHA in pancreatic cancer and suggested that LDHA might be a potential therapeutic target.

Altered expression of SIRT gene family in head and neck squamous cell carcinoma

Abstract: Head and neck squamous cell carcinoma (HNSCC) include a group of malignant neoplasms that arise from the upper aerodigestive tract and represent the seventh most common cause of cancer-related death. The overall 5-year survival rates have not significantly improved for decades in spite of the advances in the field of oncology and surgery, encouraging further research on factors that might modify disease prognosis. The silent information regulator (SIR) genes (Sirtuins) play key roles in cellular stress and are associated with aging-related diseases including cancer. Currently, seven human sirtuin (SIRT1–7) genes have been identified, but the roles of SIRT genes in HNSCC are still uncertain. Therefore, in this study, we used real-time quantitative reverse transcription-polymerase chain reaction to investigate the expressions of the seven SIRT genes in human HNSCC tissues to assess the changes in cancerous and noncancerous parts and the correlation with different tumor behaviors. Our results demonstrated that the expression levels of SIRT1, SIRT2, SIRT3, SIRT5, SIRT6, and SIRT7 were significantly downregulated in cancerous tissues compared with noncancerous tissues (all p < 0.01). The expression levels of SIRT1, SIRT2, SIRT3, SIRT5, and SIRT7 showed downregulation in advanced stages in respect to early stages (p < 0.05). These results indicate that the downregulation of SIRT genes expression may contribute to the development of cancer and trigger the neoplastic disease to more advanced stages. Our study indicates that SIRT genes expression could help in the diagnosis and represent a prognostic biomarker in HNSCC.

MicroRNAs in osteosarcoma: diagnostic and therapeutic aspects

Abstract: MicroRNAs (miRNAs) are small RNA molecules, which can interfere with the expression of several genes and act as gene regulator. miRNAs have been proved as a successful diagnostic and therapeutic tool in several cancers. In this review, the differential expression of miRNAs in osteosarcoma and their possibility to be used as diagnostic and therapeutic tools have been discussed. Osteosarcoma is the most common primary bone tumor that mainly affects children and adolescents. The current treatment of osteosarcoma remains difficult, and osteosarcoma causes many deaths because of its complex pathogenesis and resistance to conventional treatments. Several studies demonstrated that the differential expression patterns of miRNAs are a promising tool for the diagnosis and treatment of osteosarcoma. Although some aspect of the mechanism of action of miRNAs in controlling osteosarcoma has been identified (e.g., targeting the Notch signaling pathway), it is far beyond to the clear understanding of miRNA targets in osteosarcoma. Identification of the specific target of miRNAs may aid molecular targets for drug development and future relief of osteosarcoma.

High intratumoral expression of fibroblast activation protein (FAP) in colon cancer is associated with poorer patient prognosis

Abstract: -An active stroma is important for cancer cell invasion and metastasis. We investigated the expression of fibroblast activation protein (FAP) in relation to patient prognosis in colorectal cancer. Colorectal cancer specimens from 449 patients were immunohistochemically stained with a FAP antibody and evaluated in the tumor center and tumor front using a semiquantitative four-level scale. FAP was expressed by fibroblasts in 85–90 % of the tumors examined. High versus no/low expression in the tumor center was associated with poor prognosis (multivariate hazard ratio, HR = 1.72; 95 % CI 1.07–2.77, p = 0.025). FAP expression in the tumor front, though more frequent than in the tumor center, was not associated with prognosis. FAP expression in the tumor center was more common in specimens with positive microsatellite instability (MSI) screening status and in patients with high CpG island methylator phenotype (CIMP) status. However, inclusion of MSI screening status and CIMP status in the multivariate analysis strengthened the risk estimates for high FAP expression in the tumor center (HR = 1.89; 95 % CI 1.13–3.14; p = 0.014), emphasizing the role of FAP as an independent prognostic factor. Stromal FAP expression is common in colorectal cancer, and we conclude that high FAP expression in the tumor center, but not the tumor front, is an independent negative prognostic factor.

Current understanding of the role and targeting of tumor suppressor p53 in glioblastoma multiforme

Abstract: Glioblastoma multiforme (GBM) is the most common primary malignancy in the brain and confers a uniformly poor prognosis. Despite decades of research on the topic, limited progress has been made to improve the poor survival associated with this disease. GBM arises de novo (primary GBM) or via dedifferentiation of lower grade glioma (secondary GBM). While distinct mutations are predominant in each subtype, alterations of tumor suppressor p53 are the most common, seen in 25–30 % of primary GBM and 60–70 % of secondary GBM. Various roles of p53 that protect against neoplastic transformation include modulation of cell cycle, DNA repair, apoptosis, senescence, angiogenesis, and metabolism, resulting in an extremely complex signaling network. Mutations of p53 in GBM are most common in the DNA-binding domain, namely within six hotspot mutation sites (codons 175, 245, 248, 249, 273, and 282). These alterations generally result in loss-of-function, gain-of-function, and dominant-negative mutational effects for p53, however, the distinct effect of these mutation types in GBM pathogenesis remain unclear. Signaling alterations downstream from p53 (e.g., MDM2, MDM4, INK4/ARF), p53 isoforms (e.g., p63, p73), and microRNAs (e.g., miR-34) also play critical roles in modulating the p53 pathway. Despite novel mouse models of GBM showing that p53 combined with other mutation generate tumors de novo, the role of p53 as a molecular marker of GBM remains controversial with most studies failing to show an association with prognosis. Regarding treatment in GBM, p53 targeted-gene therapy and vaccinations have reached phase I clinical trials while therapeutic drugs are still in preclinical development. This review aims to discuss the most recent findings regarding the impact of p53 mutations on GBM pathogenesis, prognosis, and treatment.

Targeting the PI3K/AKT/mTOR signaling pathway in glioblastoma: novel therapeutic agents and advances in understanding

Abstract: Glioblastoma multiforme (GBM) is a grade IV astrocytoma with a median survival of 12 months despite current multi-modal treatment options. GBM is distinguished clinicopathologically into primary and secondary subtypes. Mutations of phosphatase and tensin homolog, and subsequent upregulation of the downstream protein kinase B/mammalian target of rapamycin (mTOR) signaling pathway, are commonly seen in primary GBM and less predominantly in secondary GBM. While investigations into targeted treatments of mTOR have been attempted, feedback regulation within the mTOR signaling pathway may account for therapeutic resistance. Currently, rapamycin analogs, dual-targeted mTOR complex 1 and 2 agents as well as dual mTOR and phosphatidylinositol-3 kinase-targeted agents are being investigated experimentally and in clinical trials. This review will discuss the experimental potential of these agents in the treatment of GBM and their current stage in the GBM drug pipeline. Knowledge obtained from the application of these agents can help in understanding the pathogenesis of GBM as well as delineating subsequent treatment strategies.

LDHA is necessary for the tumorigenicity of esophageal squamous cell carcinoma

Abstract: Esophageal squamous cell carcinoma (ESCC) is one of the most common lethal tumors in the world, and the development of new therapeutic targets is needed. Recent studies have shown that aerobic glycolysis, also known as the Warburg effect, mediated the anti-apoptotic effects in cancer cells. Lactate dehydrogenase A (LDHA) which executed the final step of aerobic lactate production has been reported to be involved in the tumor progression. However, the function of LDHA in ESCC has not been investigated. In this study, it was found that LDHA was up-regulated in ESCC clinical samples. Knockdown of the expression of LDHA inhibited cell growth and cell migration in vitro as well as tumorigenesis in vivo. With regard to the molecular mechanism, silencing the expression of LDHA was related to decreased AKT activation and cyclin D1 expression and increased cleavage of PARP and caspase 8. Taken together, our findings suggest that LDHA plays an important role in the progression of ESCC by modulating cell growth, and LDHA might be a potential therapeutic target in ESCC.

miR-221/222: promising biomarkers for breast cancer.

Abstract: MicroRNAs (miRNAs) are small noncoding RNAs of 19–25 nt that can regulate gene expression at a posttranscriptional level. Increasing evidence indicates that miRNAs participate in almost every step of cellular processes and are often aberrantly expressed in human cancer. miR-221 and miR-222 are two highly homologous miRNAs that always act as a gene cluster (miR-221/222) in cellular regulation and have extensively been studied in cancer network. Here, we review the role of miR-221/222 in breast cancer (BCa) development and progression: regulating proliferative signaling pathways, altering telomere and telomerase activity, avoiding cell death from tumor suppressors, autophagy and apoptosis, monitoring angiogenesis, supporting epithelial–mesenchymal transition, and even controlling cell-specific function within microenvironment. We consider that miR-221/222 act as promising biomarkers for BCa and they would offer a new way in molecular targeting cancer treatment.

Alpha-fetoprotein: a renaissance

Abstract: Alpha-fetoprotein (AFP) is a major mammalian embryo-specific and tumor-associated protein that is also present in small quantities in adults at normal conditions. Discovery of the phenomenon of AFP biosynthesis in carcinogenesis by G. Abelev and Yu. Tatarinov 50 years ago, in 1963, provoked intensive studies of this protein. AFPs of some mammalian species were isolated, purified and physico-chemically and immunochemically characterized. Despite the significant success in study of AFP, its three-dimensional structure, mechanisms of receptor binding along with a structure of the receptor itself and, what is the most important, its biological role in embryo- and carcinogenesis remain still obscure. Due to difficulties linked with methodological limitations, research of AFP was to some extent extinguished by the 1990s. However, over the last decade a growing number of investigations of AFP and its usage as a tumor-specific biomarker have been observed. This was caused by the use of new technologies, primarily, computer-based and genetic engineering approaches in studying of this very important oncodevelopmental protein. Our review summarizes efforts of different scientific groups throughout the world in studying AFP for 50 years with emphasis on detailed description of recent achievements in this field.

Biomarkers for pancreatic cancer: promising new markers and options beyond CA 19-9

Abstract: Pancreatic adenocarcinoma accounts for nearly 90–95 % of exocrine malignant tumors of the pancreas. Traditionally, overexpressed proteins/epitopes such as CA 19-9, CA-50, CEA, and many others were being used as pancreatic cancer tumor markers. The main utility of these biomarkers was in the diagnosis of pancreatic cancer as well as to assess response to chemotherapy and to determine prognosis and to predict tumor recurrence. However, these markers had significant limitations such as lack of sensitivity, false-negative results in certain blood groups, as well as false-positive elevation in the presence of obstructive jaundice. To circumvent these limitations, an extraordinary amount of research is being performed to identify an accurate tumor marker or a panel of markers that could aid in the management of the pancreatic cancer. Although this research has identified a large number and different variety of biomarkers, few hold future promise as a preferred marker for pancreatic cancer. This review provides an insight into exciting new areas of pancreatic biomarker research such as salivary, pancreatic juice, and stool markers that can be used as a noninvasive test to identify pancreatic cancer. This manuscript also provides a discussion on newer biomarkers, the role of microRNAs, and pancreatic cancer proteomics, which have the potential to identify a preferred tumor marker for pancreatic adenocarcinoma. This review further elaborates on important genetic changes associated with the development and progression of pancreatic cancer that holds the key for the identification of a sensitive biomarker and which could also serve as a therapeutic target.

The role of novel biomarker HE4 in endometrial cancer: a case control prospective study

Abstract: The aim of the study was to explore the clinical value of serum human epididymis secretory protein E4 (HE4) and CA125 in endometrial carcinoma. From January 2010 to April 2012, serum specimens were collected from consecutive cases of endometrial carcinoma and from cases of uterus benign disease (control group). The CA125 normal value is considered less than 35 U/mL. Two HE4 cutoff are considered: less than 70 pmol/L and less than 150 pmol/L. The specificity analysis was performed using the Mann–Whitney test for the CA125 and HE4 series. The level of statistical significance is set at p < 0.05. The sensitivity of CA125 in detecting endometrial cancer is 19.8 %, whereas the sensitivity of HE4 is 59.4 and 35.6 % for 70 and 150 pmol/L cutoff, respectively. Thus the specificity of HE4 is 100 % (positive predictive value = 100 %, negative predictive value = 71.52 and 61.31 % considering the two HE4 cutoff, respectively), whereas the CA125 specificity is 62.14 % (positive predictive value = 33.9 %, negative predictive value = 44.14 %) in detection of endometrial cancer. Combining CA125 and HE4, the sensitivity to detect endometrial cancer is 60.4 and 34.6 %, at HE4 cutoff of 70 and 150 pmol/L, respectively, with a specificity of 100 %. HE4 may be a new tool for preoperative evaluation and postoperative surveillance of endometrial cancer patients, with a positive predictive value = 100 %. HE4 at cutoff of 70 pmol/L yields the best sensitivity and specificity.

Increased activation of PI3K/AKT signaling pathway is associated with cholangiocarcinoma metastasis and PI3K/mTOR inhibition presents a possible therapeutic strategy.

Abstract: Phosphatidylinositol 3-kinase (PI3K) signaling plays a critical role in cholangiocarcinoma (CCA), as well as anti-cancer drug resistance and autophagy, the type II program cell death regulation. In this work, we aimed to: (1) determine the expression levels of several key components of PI3K signaling and (2) evaluate whether NVP-BEZ235, a novel dual PI3K/mTOR inhibitor, could inhibit CCA cell growth. Immunohistochemistry for p85α, p110α, AKT, p-AKT (T308), mTOR, p-mTOR (S2448), GSK-3β, p-GSK-3β (S9), PTEN, and p-PTEN (S380, T382/383) was performed in 30 CCA patients. Western blotting was used to analyze PTEN and p-PTEN expression in the cell lines (KKU-OCA17, KKU-100, KKU-M055, KKU-M139, KKU-M156, KKU-M213, and KKU-M214). The effects of NVP-BEZ235 on CCA cells were evaluated using a growth inhibition assay, flow cytometer and migration assay. Increased activation of PI3K/AKT signaling was reproducibly observed in the CCA tissues. The expression of p85α, mTOR, and GSK-3β was significantly correlated with metastasis. Interestingly, PTEN suppression by loss of expression or inactivation by phosphorylation was observed in the majority of patients. Furthermore, NVP-BEZ235 effectively inhibited CCA cell growth and migration through reduced AKT and mTOR phosphorylation and significantly induced G1 arrest without apoptosis induction, although increase autophagy response was observed. In conclusion, the constitutive activation of PI3K/AKT pathway in CCA is mainly due to PTEN inactivation by either loss of expression or phosphorylation along with an increased expression in its pathway components heralding a poor prognosis for CCA patients. This work also indicates that inhibition of PI3K and mTOR activity by the inhibitor NVP-BEZ235 has anti-cancer activity against CCA cells which might be further tested for CCA treatment.

Adenosine induces cell cycle arrest and apoptosis via cyclinD1/Cdk4 and Bcl-2/Bax pathways in human ovarian cancer cell line OVCAR-3

Abstract: Adenosine is a regulatory molecule with widespread physiological effects in almost every cells and acts as a potent regulator of cell growth. Adenosine has been shown to inhibit cell growth and induce apoptosis in the several cancer cells via caspase activation and Bcl-2/Bax pathway. The present study was designed to understand the mechanism underlying adenosine-induced apoptosis in the OVCAR-3 human ovarian cancer cells. MTT viability, BrdU and cell counting assays were used to study the cell proliferation effect of adenosine in presence of adenosine deaminase inhibitor and the nucleoside transporter inhibitor. Cell cycle analysis, propidium iodide and annexin V staining, caspase-3 activity assay, cyclinD1, Cdk4, Bcl-2 and Bax protein expressions were assessed to detect apoptosis. Adenosine significantly inhibited cell proliferation in a concentration-dependent manner in OVCAR-3 cell line. Adenosine induced cell cycle arrest in G0/G1 phase via Cdk4/cyclinD1-mediated pathway. Adenosine induced apoptosis, which was determined by Annexin V-FITC staining and increased sub-G1 population. Moreover, down-regulation of Bcl-2 protein expression, up-regulation of Bax protein expression and activation of caspase-3 were observed in response to adenosine treatment. The results of this study suggest that extracellular adenosine induced G1 cell cycle arrest and apoptosis in ovarian cancer cells via cyclinD1/ Cdk4 and Bcl-2/Bax pathways and caspase-3 activation. These data might suggest that adenosine could be used as an agent for the treatment of ovarian cancer.

A comparative overview of general risk factors associated with the incidence of colorectal cancer.

Abstract: Cancers found in colorectal region remain largely localized to the large intestine and rectum. They are derived from the epithelium and are considered to be among the most frequently detected cancers. They are known to occur in approximately 5 % population of the Western world. After metastasis, a patient’s 5-year postsurgical survival chances unfortunately fall from 90 to 10 % or even less. Adenocarcinoma, the most common cell type of colon cancer, alone constitutes 95 % of the cases. Lymphoma and squamous cell carcinoma can also be found in some cases. Because 5 % of persons are predisposed to development of colorectal cancer, this disease has often been addressed as an important public health issue. Factors that are known in particular to increase a person’s risk to develop this cancer are as follows: an individual’s age, dietary habits, any complaint of obesity, diabetes, previous history of cancer or intestinal polyps, personal habit of alcohol consumption and smoking, family history of colon cancer, race, sex, and ethnicity. Since the risk of colorectal cancer is increasing steadily in Kashmir, India, like in some other corners of Asia, exhaustive efforts are being made to find the association of above given and other risk factors with the development of this gastrointestinal tract cancer. Adoption of Western life style, diet mimicry, together with a habit of having physically inactive life style and consumption of red meat in particular can be blamed as being active players to a considerable extent.

Apoptosis induction in human glioblastoma multiforme T98G cells upon temozolomide and quercetin treatment

Abstract: Glioblastoma multiforme is the most aggressive primary brain tumour. At the cellular and molecular levels, several mechanisms responsible for apoptosis or autophagy induction are blocked. Identification of molecular targets stimulating cells to initiate programmed cell death should be performed for therapeutic purposes. A promising solution is the combination of temozolomide and quercetin. The aim of our study was to evaluate the effect of both drugs, applied alone and in combinations, on apoptosis and autophagy induction in human glioblastoma multiforme T98G cells. Our results clearly indicate that quercetin and temozolomide induce apoptosis very significantly, having no effect on autophagy induction. At the molecular level, it was correlated with caspase 3 and 9 activation, cytochrome c release from the mitochondrium and a decrease in the mitochondrial membrane potential. Both drugs are also potent Hsp27 and Hsp72 inhibitors. This suggests that the apoptotic signal goes through an internal pathway. Increased expression of caspase 12 and the presence of several granules in the cytoplasm after temozolomide treatment with or without quercetin preceding appearance of apoptosis may suggest that apoptosis is initiated by ER stress. Additionally, it was accompanied by changes in the nuclear morphology from circular to ‘croissant like’.

Characterization of cell-free circulating DNA in plasma in patients with prostate cancer.

Abstract: Cell-free circulating DNA in plasma and serum may serve as a biomarker for malignant tumor detection and follow up in patients with a variety of solid tumors including prostate cancer. In healthy patients, DNA is normally released from an apoptotic source which generates small fragments of cell-free DNA, whereas cancer patients have cell-free circulating DNA that originated from necrosis, autophagy, or mitotic catastrophe. Cell-free circulating DNA levels were measured by a quantitative real-time PCR method with a set of primers targeted to amplify the consensus ALU apoptotic versus necrotic origin. Prostate cancer patients before and 3 months after diagnosis showed cell-free circulating DNA released at apoptotic and non-apoptotic cell death. Interestingly, all patients after 6 months demonstrated DNA released at non-apoptotic cell. The principal source of cell-free circulating DNA is of apoptotic and non-apoptotic cell death. However, during treatment, this feature could change. Therefore, the study of cell-free circulating DNA would be important to follow the evolution of the disease during the treatment.

Serum 25-hydroxyvitamin D and breast cancer risk: a meta-analysis of prospective studies.

Abstract: There were some case–control studies, nested case–control studies, and cohort studies with controversial results on the association between serum 25-hydroxyvitamin D [25(OH)D] and breast cancer risk. Case–control studies are prone to selection bias, which limit the strength and quality of the evidence. To overcome the shortcoming of the case–control studies, the meta-analysis of prospective studies including nested case–control studies and cohort studies was conducted. PubMed, Embase, and Web of Science databases were searched, and the last retrieval date was March 24, 2013. For the highest versus the lowest level of serum 25(OH)D, the relative risks (RRs) and its 95 % confidence intervals (CIs) from each study were used to estimate summary RR and its 95 % CI. Subgroup analyses by geographic region, menopausal status, and adjusted status of RR were also performed, respectively. A dose–response association between serum 25(OH)D concentration and breast cancer risk was assessed. Fourteen articles with 9,110 breast cancer cases and 16,244 controls were included in the meta-analysis. Overall, serum 25(OH)D levels were inversely significantly associated with breast cancer risk (RR = 0.845, 95 % CI = 0.750–0.951). Inversely statistically significant associations were observed in North American studies, postmenopausal women, and studies with adjusted and unadjusted RR, respectively. No statistically significant associations were observed in European studies and premenopausal women, respectively. Dose–response analysis showed that every 10 ng/mL increment in serum 25(OH)D concentration was associated with a significant 3.2 % reduction in breast cancer risk. This meta-analysis provides evidence of a significantly inverse association between serum 25(OH)D concentration and breast cancer risk.

Decreased expression of long noncoding RNA AC096655.1-002 in gastric cancer and its clinical significance

Abstract: Long noncoding RNAs (lncRNAs) are newfound noncoding RNAs that are greater than 200 nucleotides in length. They have emerged recently as major players in governing fundamental biological processes. However, the expression level of lncRNAs and their clinical significances are not well understood. To investigate the lncRNA expression in gastric cancer, real-time reverse transcriptase-polymerase chain reaction was conducted. Then, the association between the level of AC096655.1-002, one of lncRNA, in gastric cancer tissues and the clinicopathological features of patients with gastric cancer was further analyzed. Receiver operating characteristic (ROC) curve was constructed to evaluate the diagnostic values. The results showed that AC096655.1-002 was significantly downregulated in gastric cancer tissues compared with paired adjacent non-tumorous tissues (P < 0.001). Its expression level was significantly correlated with lymph node metastasis (P < 0.001), distant metastasis (P < 0.001), tumor–node–metastasis stages (P < 0.001), and differentiation (P = 0.030). The area under the ROC curve of AC096655.1-002 was up to 0.731. For the detection of gastric cancer, the use of AC096655.1-002 showed a remarkable improvement compared with the use of serum carcinoembryonic antigen. These results indicated that lncRNA AC096655.1-002 may be a potential biomarker in the diagnosis of gastric carcinoma.

miR-214 promotes tumorigenesis by targeting lactotransferrin in nasopharyngeal carcinoma

Abstract: LTF (lactotransferrin, or lactoferrin) plays important role in innate immunity, and its anti-tumor function has also been reported in multiple cancers. We previously reported that LTF is significantly down-regulated in nasopharyngeal carcinoma (NPC) and acts as a tumor suppressor by suppressing AKT signaling. However, the exact mechanism of the down-regulation of LTF in NPC has not been revealed. In the current study, we screened and identified LTF is a bona fide target of miR-214 in NPC cells. miR-214 mimics significantly suppressed LTF mRNA and protein expression levels in NPC cells. miR-214 not only can promote NPC cell proliferation and invasion abilities in vitro, but also can accelerate tumor formation and lung metastasis in a mouse xenograft model. The pro-tumor function of miR-214 was depended on LTF suppression since LTF re-expression can reverse it. miR-214 can also activate AKT signaling by suppressing LTF expression. Furthermore, miR-214 expression level was up-regulated in NPC especially in metastasis-prone NPC tumor tissues compared with normal nasopharyngeal epithelial tissues, while the LTF expression level was negatively correlated with miR-214, suggesting that miR-214 targeting is partly responsible for LTF down-regulation in NPC specimens.

Anti-cancer activity of DHA on gastric cancer—an in vitro and in vivo study

Abstract: Treatment of gastric cancer remains a major challenge, and new anticancer drugs are urgently required. This study investigated whether dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, could inhibit the growth of gastric cancer both in vitro and in vivo. A series of in vitro experiments including MTT, colony-forming, wound healing, invasion, cell cycle, cellular senescence, and apoptosis assays were performed to examine the antiproliferative and antimetastatic effects of DHA on three gastric cancer cell lines, SGC-7901, BGC823, and MGC803. The result showed that the proliferation rate and colony-forming abilities of gastric cancer cells were significantly suppressed by DHA together with significant suppression of the expressions of proliferation markers (PCNA, cyclin E, and cyclin D1), and upregulation of p21 and p27. Moreover, DHA induced cellular senescence, G1 phase cell cycle arrest and hindered the migration and invasion of gastric cancer cells corresponding with downregulation of MMP-9 and MMP-2. Furthermore, DHA significantly induced apoptosis through suppressing Bcl-2 as well as activating caspase-9 and PARP. Treatment of gastric cancer cells with DHA increased miR-15b and miR-16 expression, caused a downregulation of Bcl-2, resulting in apoptosis of gastric cancer cells. In vivo, our data showed that DHA significantly inhibited the growth of SGC7901 cell-transplanted tumors. In summary, we have shown that DHA is able to inhibit the growth and metastasis of human gastric cancer. The modulation of miR-15b and miR-16 mediated the apoptosis effects of DHA in gastric cancer cells. Our work suggested that DHA has significant anticancer effects against gastric cancer both in vivo and in vitro, indicating that it is a promising therapy for human gastric cancer.

Expression and regulatory function of miRNA-34a in targeting survivin in gastric cancer cells

Abstract: We aimed to investigate the expression of microRNA-34a (miR-34a) in human gastric cancer cells and to evaluate the effects of miR-34a, acting via its gene survivin, on gastric cancer cell HGC-27 to provide potential new strategies for treating gastric cancer. In vitro cultures of the human gastric cancer cell lines MGC80-3, HGC-27, NCI-N87, and SGC-7901 and the normal human gastric epithelial cell line GES-1 were established. The expression of miR-34a in each gastric cancer cell line and GES-1 normal human gastric epithelial cell line was detected using quantitative real-time polymerase chain reaction (qRT-PCR). After the HGC-27 cells were transfected with a miR-34a mimic for 48 h, the changes in the expression levels of miR-34a were detected using qRT-PCR. The effect of miR-34a on HGC-27 cell viability was measured using a tetrazolium-based colorimetric [−(4,5)-dimethylthiahiazo-(−z-y1)-3,5-di-phenytetrazoliumromide (MTT)] assay. Flow cytometry was used to analyze the effects of miR-34a on HGC-27 cell proliferation. Annexin V/propidium iodide double staining and flow cytometry were used to analyze the effects of miR-34a on HGC-27 cell apoptosis. A Transwell invasion chamber was used to detect the effects of miR-34a on HGC-27 cell invasion. Finally, western blotting was used to analyze the effects of miR-34a on survivin protein expression. The qRT-PCR test determined that miR-34a expression in gastric cancer cells was significantly reduced compared to the normal gastric epithelial cell line GES-1 (p < 0.01). Compared to the control group, cellular miR-34a expression levels were significantly increased in HGC-27 human gastric carcinoma cells after transfection with a miR-34a mimic for 48 h (p < 0.01). The MTT assay demonstrated that after overexpressing miR-34a in HGC-27 cells, cellular viability was significantly reduced (p < 0.05). Flow cytometry analysis determined that upon miR-34a overexpression, the proliferation index decreased significantly (p < 0.05), and cellular apoptosis was significantly increased (p < 0.01). The Transwell invasion chamber assay illustrated that after increasing the expression of miR-34a, the number of cells passing through the Transwell chamber was significantly reduced (p < 0.01). Based on western blotting, compared with the control group, survivin protein expression levels were significantly decreased in the HGC-27 cells transfected with the miR-34a mimic for 48 h (p < 0.01). In conclusion, the expression level of miR-34a was downregulated in human gastric cancer cell lines. miR-34a can negatively regulate survivin protein expression and inhibit gastric cancer cell proliferation and invasion. Therapeutically enhancing miR-34a expression or silencing the survivin gene may benefit patients with gastric cancer.

MiR-210 expression in tumor tissue and in vitro effects of its silencing in renal cell carcinoma.

Abstract: Renal cell carcinoma (RCC) is the most common neoplasm of adult kidney accounting for about 3 % of adult malignancies. MicroRNAs (miRNAs) are a class of naturally occurring, short non-coding RNAs that regulate gene expression at the post-transcriptional level. We determined global miRNA expression profiles of RCC and parallel renal parenchyma tissues by using quantitative reverse transcriptase-polymerase chain reaction-based TaqMan low-density arrays. Afterward, we validated the difference in miR-210 expression levels on the larger group of RCC patients (35 RCC versus 10 non-tumorous parenchyma samples). Functional in vitro experiments were performed on ACHN and CAKI-2 RCC cell lines transfected with miRNA-210 inhibitor. Cell viability, apoptosis, cell cycle, scratch wound migration assay, and invasion assay (xCELLigence) were performed. We have identified original ccRCC-specific miRNA signature in clinical samples (73 miRNAs were significantly downregulated and five miRNAs upregulated (P < 0.003)). Increased expression levels of miR-210 in RCC tumor tissue were independently validated. We observed decreased viability of ACHN and CAKI-2 cells and accumulation of CAKI-2 in G2 phase of cell cycle after silencing of miR-210 expression. Downregulation of miR-210 also reduced the migratory and invasive potential of ACHN metastatic RCC cells. Moreover, we showed downregulation of HIF1a protein in both cell lines after miR-210 silencing indicating participation of miR-210 in hypoxic processes of RCC not only through regulation of its target mRNAs but also by indirect regulation of HIF1a. To our knowledge, this is the first report to show miR-210 regulatory effects on cell migration, invasive potential, and HIF1a protein in RCC cells.

Clinical and prognostic significance of Yes-associated protein in colorectal cancer

Abstract: The Hippo signaling pathway is a critical regulator of organ size control during development, and its deregulation is associated with cancers. Acting downstream of this pathway, Yes-associated protein (YAP) was implicated in tumorigenesis. The present study aimed to explore the expression patterns and clinical significance of YAP in human colorectal cancer (CRC). In addition, we investigated the relationship between YAP expression and Wnt/β-catenin pathway activation in CRC. A total of 139 cases of CRC tissues were investigated by immunohistochemistry for the expression of YAP, cyclin D1, and β-catenin. The association between YAP expression and clinicopathologic features was analyzed. Our results showed that YAP was overexpressed in 52.5 % (73/139) cases of CRC and predominantly presented in the nucleus. There was an excellent correlation between YAP expression and pTNM stage (p = 0.0024). YAP expression in CRC was significantly correlated with nodal status (p = 0.0034), tumor status (p = 0.0382), and cyclin D1 overexpression (p < 0.0001). Importantly, YAP expression was associated with short overall survival (p < 0.001). Furthermore, patients with YAP-positive and nuclear β-catenin-positive profiles had worse overall survival. Univariate and multivariate analyses revealed that YAP expression was an independent prognostic indicator of CRC (p = 0.0207). Our results indicated that YAP overexpression contributed to the tumorigenesis and played a pivotal role in the progression in CRC, and the interaction of YAP and Wnt/β-catenin pathways needs further exploration.

Circulating immunogenic cell death biomarkers HMGB1 and RAGE in breast cancer patients during neoadjuvant chemotherapy

Abstract: Neoadjuvant chemotherapy in breast cancer patients aims at preoperative reduction of tumor volume for better resection results and prognosis. As not all patients respond to neoadjuvant therapy, predictive biomarkers are needed for more efficient individual management. In prospectively collected sera of 51 consecutive locally confined breast cancer (LBC) patients receiving preoperative, neoadjuvant chemotherapy, value level kinetics of soluble high mobility group box 1 (HMGB1), soluble receptor for advanced glycation end products (sRAGE) as well as the established breast cancer biomarkers CA 15–3 and carcinoembryonic antigen (CEA) were investigated and correlated with therapy response objectified by pathological staging at surgery. In addition, biomarkers were measured in sera of 30 healthy controls (HC), 13 patients with benign breast diseases, and 28 metastatic breast cancer (MBC) patients. Pretherapeutic levels of soluble HMGB1 were decreased in MBC, while sRAGE was already decreased in LBC. In contrast, CA 15–3 and CEA were strongly elevated in MBC, but not in LBC. Combination of sRAGE and CA 15–3 enabled best discrimination of LBC from HC (AUC 78.2 %; sens 58 % at 95 % spec), while CA15-3 and CEA discriminated best between MBC and all controls (AUC 90.9 %; sens 70 % at 95 % spec). In LBC patients undergoing neoadjuvant chemotherapy, nine patients achieved complete remission (CR), 29 achieved partial remission (PR), while 13 had no change of disease (NC). NC patients tended to have higher HMGB1 and lower sRAGE levels before therapy onset (p = 0.056 and p = 0.054), while CA 15–3 and CEA did not predict therapeutic outcome. Furthermore, kinetics of HMGB1 during therapy correlated with efficacy of the treatment (p = 0.053). Markers of immunogenic cell death are valuable for the diagnosis of MBC and early estimation of response to neoadjuvant therapy in LBC patients.