Jun-chao Guo1, Yu-pei Zhao, Quan Liao, Yu Zhu. 1. Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing 100730, China.
Abstract
OBJECTIVE: To delineate the mechanism of primary drug resistance in pancreatic cancer cell lines by investigating multidrug resistant gene 1 and its protein (P-gp). METHODS: Reverse transcription PCR (RT-PCR) and immunocytochemistry (ICC) were carried out to investigate the expression of the MDR1 and P-gp in 8 pancreatic cancer cell lines. Flow cytometry was performed to detect P-gp function in SW1990 and HL60 cell lines. In addition, verapamil, combined with chemotherapeutic agents was carried out to evaluate its potential effect in pancreatic cancer cells. RESULTS: The highest expression level of MDR1 mRNA was proven in SW1990 cell line by RT-PCR, while the absent expression was found in PCT-2. Weak MDR1 mRNA expression were found in PCT-3, PCT-4, ASPC, Cap-1, Mia-PaCa-2 and Panc-1 cell lines. ICC showed that P-gp was localized mainly in the membrane and partly in the plasma. P-gp overexpression was also present in SW1990. The accumulation of Rhodamin123 in SW1990 was significantly decreased (57.9% +/- 5.4%) compared with its expression in HL60 (99.5% +/- 3.3%) (P < 0.05). Verapamil (VPM), combined with ADM or E-ADM showed a potential effect on reversing drug resistance mediated by P-gp in pancreatic cancer chemotherapy. CONCLUSIONS: MDR1 and its protein P-gp are indeed expressed in some extent in pancreatic cancer cell lines. VPM combined with ADM might imply a new strategy in pancreatic cancer chemotherapy.
OBJECTIVE: To delineate the mechanism of primary drug resistance in pancreatic cancer cell lines by investigating multidrug resistant gene 1 and its protein (P-gp). METHODS: Reverse transcription PCR (RT-PCR) and immunocytochemistry (ICC) were carried out to investigate the expression of the MDR1 and P-gp in 8 pancreatic cancer cell lines. Flow cytometry was performed to detect P-gp function in SW1990 and HL60 cell lines. In addition, verapamil, combined with chemotherapeutic agents was carried out to evaluate its potential effect in pancreatic cancer cells. RESULTS: The highest expression level of MDR1 mRNA was proven in SW1990 cell line by RT-PCR, while the absent expression was found in PCT-2. Weak MDR1 mRNA expression were found in PCT-3, PCT-4, ASPC, Cap-1, Mia-PaCa-2 and Panc-1 cell lines. ICC showed that P-gp was localized mainly in the membrane and partly in the plasma. P-gp overexpression was also present in SW1990. The accumulation of Rhodamin123 in SW1990 was significantly decreased (57.9% +/- 5.4%) compared with its expression in HL60 (99.5% +/- 3.3%) (P < 0.05). Verapamil (VPM), combined with ADM or E-ADM showed a potential effect on reversing drug resistance mediated by P-gp in pancreatic cancer chemotherapy. CONCLUSIONS:MDR1 and its protein P-gp are indeed expressed in some extent in pancreatic cancer cell lines. VPM combined with ADM might imply a new strategy in pancreatic cancer chemotherapy.