Redox-mediated bypass of restriction point via skipping of G1pm

Abstract

Background: It is well known that cancer cells bypass the restriction point, R, and undergo uncontrolled cell proliferation. Hypothesis and evidence: We suggest here that fibrosarcoma cells enter G1ps directly from M, skipping G1pm, hence bypassing R, in response to redox modulation. Evidence is presented from the published literature that demonstrate a shortening of the cycle period of transformed fibroblasts (SV-3T3) compared to the nontransformed 3T3 fibroblasts, corresponding to the duration of G 1pm in the 3T3 fibroblasts. Evidence is also presented that demonstrate that redox modulation can induce the CUA-4 fibroblasts to bypass R, resulting in a cycle period closely corresponding to the cycle period of fibrosarcoma cells (HT1080). Conclusion: The evidence supports our hypothesis that a low internal redox potential can cause fibrosarcoma cells to skip the G1pm phase of the cell cycle. © 2006 Hoffman et al; licensee BioMed Central Ltd.