Purpose: Studies have shown that α-enolase ENO1 is involved in the regulation of cancer cell proliferation and metastasis. However, the role of ENO1 is yet to be explored in breast cancer. This study was undertaken to explore the role and therapeutic potential of ENO1 in breast cancer.
Methods: Expression analysis was carried out by qRT-PCR. Transfections were performed by Lipofectamine 2000 reagent. WST-1 assay was used for cell viability. Wound healing assay was used for cell migration analysis. Western blot analysis was used to determine protein expression.
Results: The results showed that the expression of ENO1 was significantly upregulated in breast cancer by up to 4-fold. Silencing of ENO1 caused significant decline in the proliferation rate and colony formation of the SK-BR-3 breast cancer cells. The decrease in the proliferation rate of the ENO1 cells was due to the induction of apoptosis as revealed by DAPI staining. Annexin V/propidium iodide (PI) showed a significant increase in the apoptotic SK-BR-3 cells. The apoptosis percentage was 2.17 in si-NC and 23.1% in si-ENO1 transfected SK-BR-3 cells. The apoptosis induction was also accompanied by increase in Bax and decrease in Bcl-2 expression. ENO1 silencing also resulted in the arrest of the SK-BR-3 cells in the G2/M phase of the cell cycle which was also associated with depletion of Cdc2, Cdc25 and cyclin B1 expression levels. ENO1 silencing also caused decrease in the migration and invasion of the SK-BR-3 cells as revealed by the wound healing and transwell assays.
Conclusion: These findings suggest that ENO1 has oncogenic properties in breast cancer which can be exploited in breast cancer treatment.