Analysis of cell proliferation and gene expression profiles in Epidermal Growth Factor-treated tumor cell lines

Aim. In order to analyze the potential carcinogenic effect of epidermal growth factor (EGF) on cancer cells, we have studied the effect of EGF in vitro experiments to follow the proliferation of tumor cells lines expressing different levels of Epidermal Growth Factor Receptor (EGFR). Additionally, in these cells, the gene expression profile involved in cancer and EGFR signaling pathways were explored. Methods. We studied the effects of nanomolar concentration (2.2, 33 and 165 nM) of recombinant human EGF (rhEGF) or control, in the proliferation of six human cancer cell lines cultured for 72 hours, stained with trypan blue and counted with a hematocytometer. The real-time PCR technique allowed to study the differential gene expression profile of 44 genes selected from the EGF signaling cascade and cancer pathway. Results. The results showed evidence of the possible correspondence between the levels of EGFR on the cells and the inhibition of cell proliferation. Other factors that could be considered are the genetic background and the concentrations of EGF added to the culture. The analysis of gene expression profile after the cell culture treatment, determined groups of genes co-expressed or co-inhibited between cell lines that over-express EGFR. Conclusion. The most downstream genes of the EGF signal cascade such as CDKN1A and caspases, are the most relevant contributors to cell proliferation and the programmed cell death regulation due to the effect of nanomolar concentration of EGF on cancer cells expressing high levels of EGFR.