In the present study we evaluated the anti-tumor potential of samsum ant venom (SAV) from Pachycondyla
sennaarensis on the human breast carcinoma cell line MCF-7. We found that SAV induced growth
arrest of MCF-7 cells without affecting the viability of MCF-10 (non-tumorigenic normal breast epithelial
cells) and normal PBMCs. We then analyzed its impact on IGF-1-mediated MCF-7 cell proliferation and its
effect on the underlying IGF-1 signaling pathways. Using flow cytometry analysis, we showed that the
percentage of apoptotic cells was fourfold higher in SAV-treated cells as compared to untreated cells.
More importantly, treatment with SAV induced a marked reduction in actin polymerization and a subsequent
marked reduction in IGF-1-mediated cell proliferation. In addition to growth-inhibitory and proapoptotic
effects, significant reductions were also observed in the phosphorylation of AKT and ERK,
but not p38MAPK, in SAV-treated cells as compared to untreated cells. Our data reveal unique anti-tumor
effects of samsum ant venom.