Document Type : Research Articles
Department of Genetics, Institute for Research and Medical Consultations, Imam Abdulrahman Bin Faisal University, P. O. Box 1982, Dammam, 31441 Saudi Arabia.
College of Biotechnology, Misr University for Science and Technology, Giza, Egypt.
Center of Research and Development, Misr University for Science and Technology, Giza, Egypt.
Center of Basic Science, Misr University for Science and Technology, Giza, Egypt.
With no sharp cure, breast cancer still be the major and the most serious life-threatening disease worldwide. Colorectal
is the third most commonly occurring cancer in men and the second most commonly occurring cancer in women. In the
present investigation, colon cancer cells (CaCo-2) and breast cancer cells (MCF-7) were treated with elevated doses
of metformin (MET) for 48h. Cell count was assessed using trypan blue test, and the cytotoxicity was evaluated using
MTT assay. Methylation-specific PCR was performed on the bisulfite-treated DNA against two tumor suppressor genes;
RASSF1A and RB. Results indicated that: in breast cancer, the cell count was decreased significantly (P>0.005) after
being treated with 5, 10, 20, 50, and 100 mM of MET. The elevated concentration had increased reduction percentages
on the MCF-7 cells, as 5 mM and 100 mM have yielded 35% and 93.3% reduction in cell viability, respectively. Colon
cancer cells have responded to the doses of MET differently, as for the 5 mM and the 100 mM, it gave 88% and 60%
reduction in cells viability, respectively. Cytotoxicity assay revealed that 5 mM and 100 mM of MET caused breast
cancer cells to loss 61.53% and 85.16% of its viability, respectively, whereas colon cancer cells have responded to the
5 mM and 100 mM of MET by reducing the cells viability with 96.91% and 96.24%, respectively. No RB promoter
methylation was detected in colon cells, while RASSF1A was partially methylated. In the MCF-7 breast cancer cells,
both RASSF1A and RB were partially methylated.