ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of anti-EGFR monoclonal antibody on the chemosensitivity of human colon cancer cells and explore the possible molecular mechanism.</p><p><b>METHODS</b>The inhibitory effect of irinotecan (CPT-11), oxaliplatin (L-OHP) and fluorouracil (5-Fu), used alone or in combination with anti-EGFR monoclonal antibody, on the proliferation of LoVo cells in vitro was assessed by MTT assay. The expressions of PI3K and Akt protein in the treated cells were examined by Western blotting, and their mRNA expressions were detected by RT-PCR.</p><p><b>RESULTS</b>Both h-R3 and C-225 treatments significantly increased the chemosensitivity of LoVo cells to irinotecan and oxaliplatin. 5-Fu and h-R3 coadministered showed a synergistic effect on the cells, but 5-Fu and C-225 had an antagonistic action. Treatment with C-225 or h-R3 resulted in lowered expressions of PI3K and Akt in LoVo cells.</p><p><b>CONCLUSION</b>Anti-EGFR monoclonal antibody can increase the chemosensitivity of human colon cancer cells to most chemotherapeutic drugs, and such effect might be attributed to the blocking of PI3K/Akt signaling pathway by these antibodies.</p>
Subject(s)
Humans , Antibodies, Monoclonal, Humanized , Therapeutic Uses , Antineoplastic Combined Chemotherapy Protocols , Therapeutic Uses , Cell Line, Tumor , Cetuximab , Colonic Neoplasms , Drug Therapy , Metabolism , Oncogene Protein v-akt , Metabolism , ErbB Receptors , Allergy and Immunology , Signal TransductionABSTRACT
<p><b>OBJECTIVE</b>To investigate the clinical significance of vascular endothelial growth factor (VEGF) levels in serums of colorectal cancer patients at stage IV.</p><p><b>METHODS</b>Using enzyme linked immunosorbent assay (ELISA) to detect the VEGF levels in serums of 45 colorectal cancer patients at stage IV, and 20 healthy served as normal control.</p><p><b>RESULTS</b>The mean concentration of VEGF in 45 colorectal cancer patients at the 7 day after operation were significantly lower than that before operation (P<0.01). The mean concentration of VEGF in the patients who benefit from bevacizumab showed no statistical difference from the levels of who did not benefit (P=0.554).</p><p><b>CONCLUSION</b>The VEGF levels in colorectal patients at stage IV are lowed as the load of tumor decrease. The circulating levels of VEGF seem not predict the response to bevacizumab in colorectal cancer patients at stage IV.</p>