OBJECTIVE To investigate the underlying mechanism of drug resistance to cisplatin and increasing the sensitivity to therapeutic drugs are key steps towards the improved treatment of patients with ovarian cancer.Gap ju...OBJECTIVE To investigate the underlying mechanism of drug resistance to cisplatin and increasing the sensitivity to therapeutic drugs are key steps towards the improved treatment of patients with ovarian cancer.Gap junction(GJ)and connexin(Cx)are closely related to tumor formation,but the relationship between cisplatin resistance and GJ or Cx are undetermined.METHODS We established the cisplatin-resistant human ovarian cancer cell line A2780-CDDP over an 11-month period,with the concentration of cisplatin gradually increasing from 0.5 g·L^(-1) to 16 g·L^(-1).To explore the effect of GJ in the process of cisplatin resistance,we investigated GJ using a parachute dyecoupling assay in A2780-RI(1.2),A2780-RI(1.7),A2780-RI(2.9),A2780-RI(4.3)and A2780-CDDP cells.We further explored whether the Cxs responsible for GJ were related to cisplatin resistance.In A2780-RI(1.2),A2780-RI(1.7),A2780-RI(2.9),A2780-RI(4.3)and A2780-CDDP,we used q-PCR to analyze the levels of Cx43,Cx40,Cx37,and Cx32.To confirm the effect of Cx32 on cisplatin resistance,we knocked down Cx32 in A2780-CDDP cells with si RNA-Cx32.As GJ was decreased whereas Cx32 expression was elevated during the cisplatin resistance process,it drove us to explore the underlying mechanism.To resolve this issue,we extracted membrane-bound and cytoplasmic proteins from A2780 and A2780-CDDP cells.RESULTS Here we showed that cisplatin resistance was correlated to the loss of GJ and the upregulation of Cx32 expression.Enhancing GJ in A2780-CDDP cells could increase the apoptotic response to cisplatin treatment.Furthermore,although Cx32 expression was increased in A2780-CDDP cells,it was more localized to the cytoplasm rather than in the membrane,and knockdown of Cx32 in A2780-CDDP cells sensitized them to cisplatin treatment.CONCLUSION In summary,Cx32 is involved in cisplatin resistance,and cytoplasmic Cx32 plays an important role in chemoresistance.展开更多
Background. The gap junction (GJ) plays important roles in the maintenance of tissue homeostasis, the control of cell growth and differentiation, and the prevention of experimental hepatocarcinogenesis. In this study,...Background. The gap junction (GJ) plays important roles in the maintenance of tissue homeostasis, the control of cell growth and differentiation, and the prevention of experimental hepatocarcinogenesis. In this study, we examined the relationship between the expression of the GJ protein connexin (Cx) 32 in 24 human hepatocellular carcinomas (HCCs) and 29 non carcinomatous liver specimens (NCLs) of 31 patients. Methods. An immunohistochemical study of Cx32 was done in 24 HCCs and 29 NCLs from 31 patients who had undergone hepatic resection. Results. The Cx32 expression decreased gradually as the disease progressed to cirrhosis and HCC. In all Cx32 positive HCCs, the expression was mostly recognized in cytoplasm, not only on the cell membrane. This internalization of Cx32 was also recognized in liver specimens showing hepatitis and cirrhosis, although it was less frequent than in the HCCs. Conclusions. These findings suggest the possibility that changes in both the amount and the distribution of Cx32 may be implicated in human hepatocarcinogenesis.展开更多
基金supported by National Natural Science Foundation of China(U1303221,81373439,81473234)Fundamental Research Funds for the Central Universities(16ykjc01,16ykzd11)
文摘OBJECTIVE To investigate the underlying mechanism of drug resistance to cisplatin and increasing the sensitivity to therapeutic drugs are key steps towards the improved treatment of patients with ovarian cancer.Gap junction(GJ)and connexin(Cx)are closely related to tumor formation,but the relationship between cisplatin resistance and GJ or Cx are undetermined.METHODS We established the cisplatin-resistant human ovarian cancer cell line A2780-CDDP over an 11-month period,with the concentration of cisplatin gradually increasing from 0.5 g·L^(-1) to 16 g·L^(-1).To explore the effect of GJ in the process of cisplatin resistance,we investigated GJ using a parachute dyecoupling assay in A2780-RI(1.2),A2780-RI(1.7),A2780-RI(2.9),A2780-RI(4.3)and A2780-CDDP cells.We further explored whether the Cxs responsible for GJ were related to cisplatin resistance.In A2780-RI(1.2),A2780-RI(1.7),A2780-RI(2.9),A2780-RI(4.3)and A2780-CDDP,we used q-PCR to analyze the levels of Cx43,Cx40,Cx37,and Cx32.To confirm the effect of Cx32 on cisplatin resistance,we knocked down Cx32 in A2780-CDDP cells with si RNA-Cx32.As GJ was decreased whereas Cx32 expression was elevated during the cisplatin resistance process,it drove us to explore the underlying mechanism.To resolve this issue,we extracted membrane-bound and cytoplasmic proteins from A2780 and A2780-CDDP cells.RESULTS Here we showed that cisplatin resistance was correlated to the loss of GJ and the upregulation of Cx32 expression.Enhancing GJ in A2780-CDDP cells could increase the apoptotic response to cisplatin treatment.Furthermore,although Cx32 expression was increased in A2780-CDDP cells,it was more localized to the cytoplasm rather than in the membrane,and knockdown of Cx32 in A2780-CDDP cells sensitized them to cisplatin treatment.CONCLUSION In summary,Cx32 is involved in cisplatin resistance,and cytoplasmic Cx32 plays an important role in chemoresistance.
文摘Background. The gap junction (GJ) plays important roles in the maintenance of tissue homeostasis, the control of cell growth and differentiation, and the prevention of experimental hepatocarcinogenesis. In this study, we examined the relationship between the expression of the GJ protein connexin (Cx) 32 in 24 human hepatocellular carcinomas (HCCs) and 29 non carcinomatous liver specimens (NCLs) of 31 patients. Methods. An immunohistochemical study of Cx32 was done in 24 HCCs and 29 NCLs from 31 patients who had undergone hepatic resection. Results. The Cx32 expression decreased gradually as the disease progressed to cirrhosis and HCC. In all Cx32 positive HCCs, the expression was mostly recognized in cytoplasm, not only on the cell membrane. This internalization of Cx32 was also recognized in liver specimens showing hepatitis and cirrhosis, although it was less frequent than in the HCCs. Conclusions. These findings suggest the possibility that changes in both the amount and the distribution of Cx32 may be implicated in human hepatocarcinogenesis.