Oncolytic viruses are natural or genetically modified viral species that selectively infect and kill neoplastic cells. Such an innate or exogenously conferred specificity has generated considerable interest around the possibility to employ oncolytic viruses as highly targeted agents that would mediate cancer cell-autonomous anticancer effects. Accumulating evidence, however, suggests that the therapeutic potential of oncolytic virotherapy is not a simple consequence of the cytopathic effect, but strongly relies on the induction of an endogenous immune response against transformed cells. In line with this notion, superior anticancer effects are being observed when oncolytic viruses are engineered to express (or co-administered with) immunostimulatory molecules. Although multiple studies have shown that oncolytic viruses are well tolerated by cancer patients, the full-blown therapeutic potential of oncolytic virotherapy, especially when implemented in the absence of immunostimulatory interventions, remains unclear. Here, we cover the latest advances in this active area of translational investigation, summarizing high-impact studies that have been published during the last 12 months and discussing clinical trials that have been initiated in the same period to assess the therapeutic potential of oncolytic virotherapy in oncological indications.

https://www.tandfonline.com/doi/pdf/10.4161/onci.28694

Trial watch: Oncolytic viruses for cancer therapy

PDK1: At the crossroad of cancer signaling pathways.

The inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis, are T cell-mediated diseases that are characterized by chronic, relapsing inflammation of the intestinal tract. The pathogenesis of IBD involves the complex interaction between the intestinal microflora, host genetic and immune factors, and environmental stimuli. Epidemiological analyses have implicated acute bacterial enteritis as one of the factors that may incite or exacerbate IBD in susceptible individuals. In this review, we examine how interactions between the common enteric pathogen Campylobacter jejuni (C. jejuni), the host intestinal epithelium, and resident intestinal microflora may contribute to the pathogenesis of IBD. Recent experimental evidence indicates that C. jejuni may permit the translocation of normal, noninvasive microflora via novel processes that implicate epithelial lipid rafts. This breach in intestinal barrier function may, in turn, prime the intestine for chronic inflammatory responses in susceptible individuals. Insights into the interactions between enteric pathogens, the host epithelia, and intestinal microflora will improve our understanding of disease processes that may initiate and/or exacerbate intestinal inflammation in patients with IBD and provide impetus for the development of new therapeutic approaches for the treatment of IBD.

https://www.physiology.org/doi/pdf/10.1152/ajpgi.00193.2009

A role for Campylobacter jejuni-induced enteritis in inflammatory bowel disease?

Potential of microalgae as a sustainable feed ingredient for aquaculture

Recent epidemiological analyses have implicated acute Campylobacter enteritis as a factor that may incite or exacerbate inflammatory bowel disease (IBD) in susceptible individuals. We have demonstrated previously that C. jejuni disrupts the intestinal barrier function by rapidly inducing epithelial translocation of non-invasive commensal bacteria via a transcellular lipid raft-mediated mechanism ('transcytosis'). To further characterize this mechanism, the aim of this current study was to elucidate whether C. jejuni utilizes M cells to facilitate transcytosis of commensal intestinal bacteria. C. jejuni induced translocation of non-invasive E. coli across confluent Caco-2 epithelial monolayers in the absence of disrupted transepithelial electrical resistance or increased permeability to a 3 kDa dextran probe. C. jejuni-infected monolayers displayed increased numbers of cells expressing the M cell-specific marker, galectin-9, reduced numbers of enterocytes that stained with the absorptive enterocyte marker, Ulex europaeus agglutinin-1, and reduced activities of enzymes typically associated with absorptive enterocytes (namely alkaline phosphatase, lactase, and sucrase). Furthermore, in Campylobacter-infected monolayers, E. coli were observed to be internalized specifically within epithelial cells displaying M-like cell characteristics. These data indicate that C. jejuni may utilize M cells to promote transcytosis of non-invasive bacteria across the intact intestinal epithelial barrier. This mechanism may contribute to the inflammatory immune responses against commensal intestinal bacteria commonly observed in IBD patients.

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Campylobacter jejuni induces transcytosis of commensal bacteria across the intestinal epithelium through M-like cells

Weighted correlation network analysis (WGCNA) is a statistical method that has been widely used in recent years to explore gene co-expression modules. Competing endogenous RNA (ceRNA) is commonly involved in the cancer gene expression regulation mechanism. Some ceRNA networks are recognized in gastric cancer; however, the prognosis-associated ceRNA network has not been fully identified using WGCNA. We performed WGCNA using datasets from The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) to identify cancer-associated modules. The criteria of differentially expressed RNAs between normal stomach samples and gastric cancer samples were set at the false discovery rate (FDR) 1.3. The ceRNA relationships obtained from the RNAinter database were examined by both the Pearson correlation test and hypergeometric test to confirm the mRNA-lncRNA regulation. Overlapped genes were recognized at the intersections of genes predicted by ceRNA relationships, differentially expressed genes, and genes in cancer-specific modules. These were then used for univariate and multivariate Cox analyses to construct a risk score model. The ceRNA network was constructed based on the genes in this model. WGCNA-uncovered genes in the green and turquoise modules are those most associated with gastric cancer. Eighty differentially expressed genes were observed to have potential prognostic value, which led to the identification of 12 prognosis-related mRNAs (KIF15, FEN1, ZFP69B, SP6, SPARC, TTF2, MSI2, KYNU, ACLY, KIF21B, SLC12A7, and ZNF823) to construct a risk score model. The risk genes were validated using the GSE62254 and GSE84433 datasets, with 0.82 as the universal cutoff value. 12 genes, 12 lncRNAs, and 35 miRNAs were used to build a ceRNA network with 86 dysregulated lncRNA-mRNA ceRNA pairs. Finally, we developed a 12-gene signature from both prognosis-related and tumor-specific genes, and then constructed a ceRNA network in gastric cancer. Our findings may provide novel insights into the treatment of gastric cancer.

/pdf/construction-and-analysis-of-the-tumor-specific-mrna-mirna-4xducj8vzw.pdf

Construction and Analysis of the Tumor-Specific mRNA-miRNA-lncRNA Network in Gastric Cancer.

CPA4 belongs to a member of the metallocarboxypeptidase family, and its expression in pancreatic cancer samples and clinical significance are still not investigated until now. In this study, we aimed to evaluate the level of CPA4 in pancreatic cancer samples and study its clinical implications as a diagnostic marker for pancreatic cancer. The levels of CPA4 in pancreatic cancer tissues and serum samples were measured by immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA), respectively. Among 150 pancreatic cancer tissues examined, 86.7% (130/150) of cases showed positive staining for CPA4. Clinicopathological relevance analysis showed that CPA4 expression was correlated with advanced clinical stage and lymph node metastasis. Also, we found that the levels of CPA4 in serum samples were significantly high in cases whose expression was also high in paired tissue samples (N=50). In a larger sample set, we found that serum CPA4 in pancreatic cancer patients was significantly higher than for healthy controls (P<0.05). In addition, high serum CPA4 was significantly associated with the TNM stage, Lymph node involvement and distant metastasis. At a cutoff value of 0.3 ng/ml, CPA4 might be a better diagnostic biomarker of pancreatic cancer than CA199. In conclusion, CPA4 overexpression is associated with pancreatic cancer progression, and it might be a potential diagnostic serum marker for pancreatic cancer.

CPA4 is a promising diagnostic serum biomarker for pancreatic cancer.

Aim: To document the clinicopathological characteristics and analyze the possible reasons for misdiagnosis or missed diagnosis of hepatoid adenocarcinoma of the stomach (HAS), using data from a single center. Methods: We retrospectively analyzed 19 patients initially diagnosed as HAS and 7 patients initially diagnosed as common gastric cancer with high levels of serum α-fetoprotein (AFP). All had undergone surgical treatment, except 3 patients only had biopsies at our hospital. Immunohistochemistry for AFP and Hepatocyte antigen was performed. Final diagnosis for these 26 patients were made after HE and immunohistochemistry slides reviewed by 2 experienced pathologists. Prognostic factors were determined by univariate analysis. Results: Nineteen cases were confirmed to be HAS. A total of 4 out of 19 cases initially diagnosed as HAS and 4 out of 7 cases initially diagnosed as common gastric adenocarcinoma were misdiagnosed/missed diagnosed, thus, the misdiagnosis/missed diagnosis rate was 30.8% (8/26). The incidence of HAS among gastric cancer in our center was 0.19% (19/9915). Sixteen (84.2%) patients showed T stages greater than T2, 12 (70.6%) patients had positive lymph nodes in 17 available patients and 3 (15.8%) of the patients with tumors presented liver metastasis at the time of diagnosis. Histologically, cytoplasmic staining types included 10 cases of eosinophilic, 1 case of clear, 5 cases of clear mixed with eosinophilic and 3 cases of basophilic. Fourteen (73.7%) patients expressed AFP, whereas only 6 (31.6%) were hepatocyte-positive. Univariate analysis showed that N stage (HR 2.429, P=0.007) and tumor AFP expression (HR 0.428, P=0.036) were significantly associated with disease-free survival. The median overall survival time was 12.0 months, and the median disease-free survival time was 7.0 months. Four (80%) of 5 N0 patients and 2 (50%) of 4 N1 patients survived without progression, but no N2-3 patients survived. Conclusion: HAS remains easily being misdiagnosed/missed diagnosed based on a pathological examination, probably because the condition is rare and has various cytoplasmic types. Although the survival rate for HAS is poor, a curative effect may be achieved for N0 or N1 cases.

Hepatoid adenocarcinoma of the stomach is a special and easily misdiagnosed or missed diagnosed subtype of gastric cancer with poor prognosis but curative for patients of pN0/1: the experience of a single center.

AIM: To investigate the therapeutic efficacy and mechanisms of action of oncolytic-herpes-simplex-virus encoding granulocyte-macrophage colony-stimulating factor (HSVGM-CSF) in pancreatic carcinoma.

METHODS: Tumor blocks were homogenized in a sterile grinder in saline. The homogenate was injected into the right armpit of each mouse. After vaccination, the mice were randomly assigned into four groups: a control group, a high dose HSVGM-CSF group [1 × 107 plaque forming units (pfu)/tumor], a medium dose HSVGM-CSF group (5 × 106 pfu/tumor) and a low dose HSVGM-CSF group (5 × 105 pfu/tumor). After initiation of drug administration, body weights and tumor diameters were measured every 3 d. Fifteen days later, after decapitation of the animal by cervical dislocation, each tumor was isolated, weighed and stored in 10% formaldehyde solution. The drug effectiveness was evaluated according to the weight, volume and relative volume change of each tumor. Furthermore, GM-CSF protein levels in serum were assayed by enzyme-linked immunosorbent assays at 1, 2, 3 and 4 d after injection of HSVGM-CSF.

RESULTS: Injection of the recombinant mouse HSV encoding GM-CSF resulted in a significant reduction in tumor growth compared to the control group, and dose-dependent effects were observed: the relative tumor proliferation rates of the low dose, medium dose and high dose groups on 15 d after injection were 45.5%, 55.2% and 65.5%, respectively. The inhibition rates of the tumor weights of the low, middle, and high dose groups were 41.4%, 46.7% and 50.5%, respectively. Furthermore, the production of GM-CSF was significantly increased in the mice infected with HSVGM-CSF. The increase in the GM-CSF level was more pronounced in the high dose group compared to the other two dose groups.

CONCLUSION: Our study provides the first evidence that HSVGM-CSF could inhibit the growth of pancreatic cancer. The enhanced GM-CSF expression might be responsible for the phenomenon.

Preclinical evaluation of herpes simplex virus armed with granulocyte-macrophage colony-stimulating factor in pancreatic carcinoma.

This study investigated the correlation between the expression of 3-phosphoinositide-dependent protein kinase-1 (PDK1) and the prognosis of gastric carcinoma patients. A total of 156 paired tumor and matched normal samples were collected from patients of gastric carcinoma who underwent surgical resection. The expression of PDK1 was analyzed by real-time quantitative PCR and immunohistochemistry method. Potential correlation between PDK1 protein expression and the clinicopathological characteristics was determined by chi-square test and Spearman correlation analysis. The influence of PDK1 expression on 5-year survival rate and survival length was determined by Kaplan-Meier analysis. The expression of PDK1 mRNA and protein were significantly higher in tumor samples comparing to those in adjacent normal samples (paired t test, P = 0.007). Immunohistochemical staining results indicated that PDK1 protein level was positively correlated with infiltration (P = 0.006). However, no associations with age, sex, clinical stage, lymph node metastasis, and distant metastasis were observed (P > 0.05). The 5-year survival rate was 20.1 and 63.4 % of the patients with high and low expression level of PDK1, respectively (P < 0.05). The median survival length was 32.5 months (95 % CI 22.8-37.6) for patients with high level of PDK1 and 63.1 months (95 % CI 52.3-64.7) for patients with low level of PDK1 (×2 = 20.153, P < 0.05). Kaplan-Meier survival curves demonstrated that elevated expression of PDK1 was an independent negative prognostic factor of gastric carcinoma (P<0.05). Our study indicated that PDK1 might serve as a candidate pro-oncogene and a potential prognostic biomarker for gastric carcinoma.

Yibin Xie

Papers

Construction and Analysis of the Tumor-Specific mRNA-miRNA-lncRNA Network in Gastric Cancer.

CPA4 is a promising diagnostic serum biomarker for pancreatic cancer.

Hepatoid adenocarcinoma of the stomach is a special and easily misdiagnosed or missed diagnosed subtype of gastric cancer with poor prognosis but curative for patients of pN0/1: the experience of a single center.

Preclinical evaluation of herpes simplex virus armed with granulocyte-macrophage colony-stimulating factor in pancreatic carcinoma.

Overexpression of 3-phosphoinositide-dependent protein kinase-1 is associated with prognosis of gastric carcinoma