Journal Article

JC Virus Mediates Invasion and Migration in Colorectal Metastasis

Link, Alexander, Nagasaka, Takeshi, Balaguer, Francesc, Jung, Barbara, Boland, C. Richard, Koi, Minoru, Shin, Sung Kwan, Goel, Ajay

2009

Overview

JC Virus (JCV), a human polyomavirus, is frequently present in colorectal cancers (CRCs). JCV large T-Ag (T-Ag) expressed in approximately half of all CRC's, however, its functional role in CRC is poorly understood. We hypothesized that JCV T-Ag may mediate metastasis in CRC cells through increased migration and invasion. CRC cell lines (HCT116 and SW837) were stably transfected with JCV early transcript sequences cloned into pCR3 or empty vectors. Migration and invasion assays were performed using Boyden chambers. Global gene expression analysis was performed to identify genetic targets and pathways altered by T-Ag expression. Microarray results were validated by qRT-PCR, protein expression analyses and immunohistochemistry. Matching primary CRCs and liver metastases from 33 patients were analyzed for T-Ag expression by immunohistochemistry. T-Ag expressing cell lines showed 2 to 3-fold increase in migration and invasion compared to controls. JCV T-Ag expression resulted in differential expression of several genetic targets, including genes that mediate cell migration and invasion. Pathway analysis suggested a significant involvement of these genes with AKT and MAPK signaling. Treatment with selective PI3K/AKT and MAPK pathway inhibitors resulted in reduced migration and invasion. In support of our in-vitro results, immunohistochemical staining of the advanced stage tumors revealed frequent JCV T-Ag expression in metastatic primary tumors (92%) as well as in their matching liver metastasis (73%). These data suggest that JCV T-Ag expression in CRC associates with a metastatic phenotype, which may partly be mediated through the AKT/MAPK signaling pathway. Frequent expression of JCV T-Ag in CRC liver metastasis provides further clues supporting a mechanistic role for JCV as a possible mediator of cellular motility and invasion in CRC.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: 1-Phosphatidylinositol 3-kinase / Aged / AKT protein / Antigen T (large) / Antigens, Viral, Tumor - genetics / Antigens, Viral, Tumor - metabolism / Biotechnology / Cancer metastasis / Cell Line, Tumor / Cell migration / Cell Movement - drug effects / Colorectal cancer / Colorectal Neoplasms - genetics / Colorectal Neoplasms - pathology / Colorectal Neoplasms - virology / DNA microarrays / Enzyme Activation - drug effects / Female / Gastroenterology and Hepatology/Colon and Rectum / Gastroenterology and Hepatology/Gastrointestinal Cancers / Gastroenterology and Hepatology/Gastrointestinal Infections / Gene expression / Gene Expression Regulation, Neoplastic - drug effects / Genes / Humans / Immunohistochemistry / JC virus / JC Virus - drug effects / JC Virus - physiology / Kinases / Liver / Liver cancer / Liver Neoplasms - secondary / Male / MAP kinase / Matching / Metastases / Middle Aged / Mitogen-Activated Protein Kinases - genetics / Mutation / Neoplasm Invasiveness / Neoplasm Metastasis - genetics / Polyomavirus / Protein Kinase Inhibitors - pharmacology / Proto-Oncogene Proteins c-akt - genetics / RNA, Messenger - genetics / RNA, Messenger - metabolism / Rodents / Signal transduction / Signal Transduction - drug effects / Signal Transduction - genetics / Signaling / Studies / Target recognition / Transcription / Transfection / Tumors / Viruses