Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Reovirus selectively replicates in and destroys cancer cells with an activated Ras signaling pathway. In this study, we evaluated the feasibility of using reovirus (serotype 3, strain Dearing) as an antihuman colon and ovarian cancer agent. In in vitro studies, reovirus infection in human colon and ovarian cell lines was assessed by cytopathic effect as detected by light microscopy, [(35)S]Methionine labeling of infected cells for viral protein synthesis and progeny virus production by plaque assay. We observed that reovirus efficiently infected all five human colon cancer cell lines (Caco-2, DLD-1, HCT-116, HT-29, and SW48) and four human ovarian cancer cell lines (MDAH2774, PA-1, SKOV3, and SW626) which were tested, but not a normal colon cell line (CCD-18Co) or a normal ovarian cell line (NOV-31). We also observed that the Ras activity in the human colon and ovarian cancer cell lines was elevated compared with that in normal colon and ovarian cell lines. In animal models, intraneoplastic as well as i.v. inoculation of reovirus resulted in significant regression of established s.c. human colon and ovarian tumors implanted at the hind flank. Histological studies revealed that reovirus infection in vivo was restricted to tumor cells, whereas the surrounding normal tissue remained uninfected. Additionally, in an i.p. human ovarian cancer xenograft model, inhibition of ascites tumor formation and the survival of animals treated with live reovirus was significantly greater than of control mice treated with UV-inactivated reovirus. Reovirus infection in ex vivo primary human ovarian tumor surgical samples was also confirmed, further demonstrating the potential of reovirus therapy. These results suggest that reovirus holds promise as a novel agent for human colon and ovarian cancer therapy.
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PMID:Oncolytic reovirus against ovarian and colon cancer. 1191 42

Many oncolytic viruses are currently being tested as potential cancer therapeutic agents. To be effective, these viruses must replicate and propagate efficiently through the tumor mass. However, it is possible that the hypoxia that characterizes many tumors may be an obstacle to viral therapy because of its inhibition of viral replication and propagation. We, therefore, decided to test how oncolytic reovirus and its target cells respond to hypoxia. We found that reovirus infection suppresses hypoxia inducible factor (HIF)-1alpha protein levels (but not transcript abundance) in colon cancer HCT116 cells under CoCl(2) or hypoxia. Reovirus infection was able to reduce HIF-1alpha levels in both von Hippel Lindau (VHL)-/- renal carcinoma A498 and p53-/- HCT116 cells, indicating that the decrease of HIF-1alpha mediated by reovirus requires neither VHL nor p53 proteins. However, treatment with the inhibitor MG132 restored HIF-1alpha levels, suggesting that reovirus-induced HIF-1alpha decrease needs proteosomal activity. A498 VHL-/- cells with constitutive expression of HIF-1alpha were relatively resistant to reovirus-induced apoptosis when compared with A498 VHL+/+ cells. However, we found that the use of YC-1 to target HIF-1alpha promoted reovirus-induced apoptosis in A498 VHL-/- cells. Accordingly, we propose that reovirus may be used together with YC-1 as a potential therapeutic agent against chemoresistant or radioresistant tumors that are hypoxic and show increased levels of HIF-1alpha.
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PMID:Down-regulation of HIF-1alpha by oncolytic reovirus infection independently of VHL and p53. 2007 85