UGCG is Involved in Oxaliplatin Resistance Mechanism of Human Colon Cancer Through Regulating MDR1/P-gp Expression

Objective  To establish and authenticate an oxaliplatin (L-OHP) resistant human colon cancer cell line, and to preliminarily explore the multidrug resistance mechanism.

Methods  An L-OHP-resistant human colon cancer cell line, HCT116/L-OHP, was established by gradually increasing the dose of L-OHP in the culture. The half inhibition concentration (IC50) of L-OHP, cisplatin (DDP) and 5-fluorouracil (5-Fu) in HCT116 and HCT116/L-OHP cell lines were evaluated by CCK8 assay. The siRNAs of UDP-glucose ceramide glucosyltransferase (UGCG) were used to transfect HCT-116/L-OHP cells. The gene and protein expression levels of UGCG and multidrug resistance gene1 (MDR1) were examined by real-time reverse transcription-polymerase chain reaction(PCR) and Western blot.

Results  The resistance index to L-OHP in HCT116/L-OHP cell line was 10.5. In addition, HCT116/L-OHP cell line had cross resistance with DDP by 4.61 of the resistance index, but not with 5-Fu. The expression levels of UGCG mRNA, MDR1 mRNA, UGCG protein and P-glycoprotein (P-gp, encoded by MDR1 gene) were significantly higher in HCT116/L-OHP cells than those in HCT116 cells (P<0.05). After transfected with UGCG siRNA, both UGCG gene and protein expression were inhibited in HCT116/L-OHP cells. Compared with the negative control, the expression of MDR1 mRNA and P-gp were also significantly decreased (P<0.05).

Conclusion  L-OHP resistant human colorectal cancer cell line HCT116/L-OHP are successfully established, and UGCG is involved in L-OHP resistance mechanism of human colon cancer through regulating MDR1/P-gp expression.