Abstract: Background and purpose: The metastasis-associated in colon cancer-1 (MACC1) is highly expressed in different cancers and has an effect on the proliferation and apoptosis of tumor cells through the regulation of extracellular signal-regulated kinase (ERK)1/2 pathway. However, the role of MACC1 in ovarian cancer has been rarely studied. The study was aimed to suppress MACC1 gene expression by siRNA and explore the relationship between MACC1 expression and chemosensitivity to cisplatin in ovarian cancer cell line SKOV3/DDP. Methods: Empty plasmid p-super-EGFP-1 (negative control group) and p-super-EGFP-MACC1 shRNA (experimental group) were transfected into ovarian cancer cell SKOV3/DDP respectively. SKOV3/DDP cells without transfection were used as blank group. Then, MACC1 mRNA and protein levels were measured by RT-PCR and Western blot, respectively. Cell proliferation and IC50 of cisplatin was determined by methyl thiazolyl tetrazolium test (MTT). Apoptosis rate was determined by flow cytometer (FCM). ERK1/2 and p-ERK1/2 protein levels were determined by Western blot. Results: Compared with those in blank and negative control groups, MACC1 mRNA and protein levels deceased in experimental group. The IC50 of cisplatin in experimental group was lower than that in the other groups (26.094 vs 47.501/47.089 μmol/L, P<0.05). There was a lower expression of p-ERK1/2 in experimental group (0.3979 vs 00.6712/0.6681, P<0.05). Apoptosis rate was significantly higher in the experimental group before and after treatment of cisplatin (1.32% vs 0.66%/0.48%, P<0.05; 36.70% vs 18.53%/16.60%, P=0.000). Conclusion: MACC1 gene may be involved in cisplatin resistance phenomenon in SKOV3/DDP cells through ERK1/2 pathway.

Key words: Metastasis-associated in colon cancer-1, Ovarian cancer, Cisplatin, Extracellular signal-regulated Kinase