Defining the regulatory mechanisms of colorectal cancer cell growth, senescence, and death will help us to develop treatment strategies for colorectal cancer. In this study, we explored the biological activities and stimulation of colorectal cancer cells in different growth environments. Specifically, we observed the growth statuses of SW480 colorectal cancer cells cultured in Leibovitz L-15 medium (L-15) and Dulbecco's modified Eagle medium (DMEM), respectively. Interestingly, SW480 cells maintained in L15 (SW480/L-15) were larger and flatter with lower proliferation rate than SW480 cells maintained in DMEM (SW480/DMEM). The expressions of P21 and P16, the regulatory proteins related to senescence and cell cycle, were significantly induced in SW480/DMEM. However, the expression of P53 was stable in SW480/L-15 and SW480/DMEM. The cell senescence-associated β-galactosidase activity was undetectable in SW480/L-15 and SW480/DMEM. These results showed that different growth conditions affect the morphology and proliferation of SW480 cells, not through cellular senescence but, perhaps, via cell cycle alteration or other signaling pathway.
