158 research outputs found

    A loop of cancer-stroma-cancer interaction promotes peritoneal metastasis of ovarian cancer via TNFα-TGFα-EGFR.

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    Peritoneum is the most common site for ovarian cancer metastasis. Here we investigate how cancer epigenetics regulates reciprocal tumor-stromal interactions in peritoneal metastasis of ovarian cancer. Firstly, we find that omental stromal fibroblasts enhance colony formation of metastatic ovarian cancer cells, and de novo expression of transforming growth factor-alpha (TGF-α) is induced in stromal fibroblasts co-cultured with ovarian cancer cells. We also observed an over-expression of tumor necrosis factor-alpha (TNF-α) in ovarian cancer cells, which is regulated by promoter DNA hypomethylation as well as chromatin remodeling. Interestingly, this ovarian cancer-derived TNF-α induces TGF-α transcription in stromal fibroblasts through nuclear factor-κB (NF-κB). We further show that TGF-α secreted by stromal fibroblasts in turn promotes peritoneal metastasis of ovarian cancer through epidermal growth factor receptor (EGFR) signaling. Finally, we identify a TNFα-TGFα-EGFR interacting loop between tumor and stromal compartments of human omental metastases. Our results therefore demonstrate cancer epigenetics induces a loop of cancer-stroma-cancer interaction in omental microenvironment that promotes peritoneal metastasis of ovarian cancer cells via TNFα-TGFα-EGFR

    Canine distemper virus induces apoptosis in cervical tumor derived cell lines

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    Apoptosis can be induced or inhibited by viral proteins, it can form part of the host defense against virus infection, or it can be a mechanism for viral spread to neighboring cells. Canine distemper virus (CDV) induces apoptotic cells in lymphoid tissues and in the cerebellum of dogs naturally infected. CDV also produces a cytopathologic effect, leading to apoptosis in Vero cells in tissue culture. We tested canine distemper virus, a member of the Paramyxoviridae family, for the ability to trigger apoptosis in HeLa cells, derived from cervical cancer cells resistant to apoptosis. To study the effect of CDV infection in HeLa cells, we examined apoptotic markers 24 h post infection (pi), by flow cytometry assay for DNA fragmentation, real-time PCR assay for caspase-3 and caspase-8 mRNA expression, and by caspase-3 and -8 immunocytochemistry. Flow cytometry showed that DNA fragmentation was induced in HeLa cells infected by CDV, and immunocytochemistry revealed a significant increase in the levels of the cleaved active form of caspase-3 protein, but did not show any difference in expression of caspase-8, indicating an intrinsic apoptotic pathway. Confirming this observation, expression of caspase-3 mRNA was higher in CDV infected HeLa cells than control cells; however, there was no statistically significant change in caspase-8 mRNA expression profile. Our data suggest that canine distemper virus induced apoptosis in HeLa cells, triggering apoptosis by the intrinsic pathway, with no participation of the initiator caspase -8 from the extrinsic pathway. In conclusion, the cellular stress caused by CDV infection of HeLa cells, leading to apoptosis, can be used as a tool in future research for cervical cancer treatment and control

    Effects of Interleukin-10 Polymorphisms, Helicobacter pylori Infection, and Smoking on the Risk of Noncardia Gastric Cancer

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    OBJECTIVE: Both variations in the interleukin-10 (IL10) gene and environmental factors are thought to influence inflammation and gastric carcinogenesis. Therefore, we investigated the associations between IL10 polymorphisms, Helicobacter pylori (H. pylori) infection, and smoking in noncardia gastric carcinogenesis in Koreans. METHODS: We genotyped three promoter polymorphisms (-1082A>G, -819T>C, and -592 A>C) of IL10 in a case-control study of 495 noncardia gastric cancer patients and 495 sex- and age-matched healthy controls. Multiple logistic regression models were used to detect the effects of IL10 polymorphisms, H. pylori infection, and smoking on the risk of gastric cancer, which was stratified by the histological type of gastric cancer. RESULTS: The IL10-819C and -592C alleles were found to have complete linkage disequilibrium, and all three IL10 polymorphisms were associated with an increased risk of intestinal-type noncardia gastric cancer. These associations were observed only in H. pylori-positive subjects and current smokers. A statistically significant interaction between the IL10-592 genotype and H. pylori infection on the risk of intestinal-type gastric cancer was observed (P for interaction  = 0.047). In addition, H. pylori-positive smokers who were carriers of either the IL10-1082G (OR [95% CI]  = 17.76 [6.17-51.06]) or the -592C (OR [95% CI]  = 8.37 [2.79-25.16]) allele had an increased risk of intestinal-type gastric cancer compared to H. pylori-negative nonsmokers homozygous for IL10-1082A and -592A, respectively. The interaction between the IL10-1082 polymorphism and the combined effects of H. pylori infection and smoking tended towards significance (P for interaction  = 0.080). CONCLUSIONS: Inflammation-related genetic variants may interact with H. pylori infection and smoking to increase the risk of noncardia gastric cancer, particularly the intestinal-type. These findings may be helpful in identifying individuals at an increased risk for developing noncardia gastric cancer

    Investigating Population Genetic Structure in a Highly Mobile Marine Organism: The Minke Whale Balaenoptera acutorostrata acutorostrata in the North East Atlantic

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    Inferring the number of genetically distinct populations and their levels of connectivity is of key importance for the sustainable management and conservation of wildlife. This represents an extra challenge in the marine environment where there are few physical barriers to gene-flow, and populations may overlap in time and space. Several studies have investigated the population genetic structure within the North Atlantic minke whale with contrasting results. In order to address this issue, we analyzed ten microsatellite loci and 331 bp of the mitochondrial D-loop on 2990 whales sampled in the North East Atlantic in the period 2004 and 2007–2011. The primary findings were: (1) No spatial or temporal genetic differentiations were observed for either class of genetic marker. (2) mtDNA identified three distinct mitochondrial lineages without any underlying geographical pattern. (3) Nuclear markers showed evidence of a single panmictic population in the NE Atlantic according STRUCTURE's highest average likelihood found at K = 1. (4) When K = 2 was accepted, based on the Evanno's test, whales were divided into two more or less equally sized groups that showed significant genetic differentiation between them but without any sign of underlying geographic pattern. However, mtDNA for these individuals did not corroborate the differentiation. (5) In order to further evaluate the potential for cryptic structuring, a set of 100 in silico generated panmictic populations was examined using the same procedures as above showing genetic differentiation between two artificially divided groups, similar to the aforementioned observations. This demonstrates that clustering methods may spuriously reveal cryptic genetic structure. Based upon these data, we find no evidence to support the existence of spatial or cryptic population genetic structure of minke whales within the NE Atlantic. However, in order to conclusively evaluate population structure within this highly mobile species, more markers will be required

    Measuring the burden of arboviral diseases: the spectrum of morbidity and mortality from four prevalent infections

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    <p>Abstract</p> <p>Background</p> <p>Globally, arthropod-borne virus infections are increasingly common causes of severe febrile disease that can progress to long-term physical or cognitive impairment or result in early death. Because of the large populations at risk, it has been suggested that these outcomes represent a substantial health deficit not captured by current global disease burden assessments.</p> <p>Methods</p> <p>We reviewed newly available data on disease incidence and outcomes to critically evaluate the disease burden (as measured by disability-adjusted life years, or DALYs) caused by yellow fever virus (YFV), Japanese encephalitis virus (JEV), chikungunya virus (CHIKV), and Rift Valley fever virus (RVFV). We searched available literature and official reports on these viruses combined with the terms "outbreak(s)," "complication(s)," "disability," "quality of life," "DALY," and "QALY," focusing on reports since 2000. We screened 210 published studies, with 38 selected for inclusion. Data on average incidence, duration, age at onset, mortality, and severity of acute and chronic outcomes were used to create DALY estimates for 2005, using the approach of the current Global Burden of Disease framework.</p> <p>Results</p> <p>Given the limitations of available data, nondiscounted, unweighted DALYs attributable to YFV, JEV, CHIKV, and RVFV were estimated to fall between 300,000 and 5,000,000 for 2005. YFV was the most prevalent infection of the four viruses evaluated, although a higher proportion of the world's population lives in countries at risk for CHIKV and JEV. Early mortality and long-term, related chronic conditions provided the largest DALY components for each disease. The better known, short-term viral febrile syndromes caused by these viruses contributed relatively lower proportions of the overall DALY scores.</p> <p>Conclusions</p> <p>Limitations in health systems in endemic areas undoubtedly lead to underestimation of arbovirus incidence and related complications. However, improving diagnostics and better understanding of the late secondary results of infection now give a first approximation of the current disease burden from these widespread serious infections. Arbovirus control and prevention remains a high priority, both because of the current disease burden and the significant threat of the re-emergence of these viruses among much larger groups of susceptible populations.</p
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