Clear cell renal cell carcinoma showed an opposite pattern with the majority having low mitochondrial (14/26, 54%) and high MDR1 staining (18/26, 69%).
Enforced expression of the connexin (Cx) 32 gene, a member of the gap junction gene family and a tumor suppressor gene in human renal cell carcinoma (RCC), enhanced vinblastine (VBL)-induced cytotoxicity in RCC cells due to suppression of multidrug resistance 1 (MDR1) expression.
The MDR1-targeted RNAi resulted in decreased MDR1 gene mRNA level (P < 0.001), almost abolished P-gp expression and reversed MDR to different chemotherapy drugs in the RCC A498 cell line.
Enforced expression of connexin (Cx) 32 gene, a member of gap junction gene family and a tumor suppressor gene in human renal cell carcinoma (RCC), enhanced vinblastine (VBL)-induced cytotoxicity on RCC cells, due to the suppression of multidrug resistance 1 (MDR1) gene product, P-glycoprotein (P-gp).
Stage adjusted disease specific survival rate, according to MDR-1 expression and therapy in patients affected by RCC in early stage (stage I), has revealed that the group of patients with high MDR-1 expression and without adjuvant therapy showed poor survival (p < 0.05).
These findings suggest that the common SNPs in the MDR1 gene have no influence on the expression of its transcript in RCC segments as well as in the normal kidney cortex.
Since these levels were lower than expected for RCC, we asked whether the metastases possessed a phenotype different from primary RCC and examined MDR-1 expression in 5 paired cell lines derived from primary and metastatic RCC.
All the N276 compounds also remarkably enhanced the sensitivity to VBL and DXR in both MDR1- and MRP-overexpressing renal cell carcinoma (RCC) cell line (NKK1), whereas they showed no potentiation of these anticancer agents in an RCC cell line (KPK1) expressing neither MDR1 nor MRP.
Multidrug resistance (MDR) in a variety of human tumors such as renal cell carcinoma (RCC) is thought to be caused by expression of the mdr1 gene and may be reversed by applying chemosensitizers such as Dexverapamil that inhibit the mdr1 gene product P-glycoprotein.
Multidrug resistance in human renal cell carcinoma is mainly caused by expression of the MDR1 gene and is characterized by a broad spectrum cross resistance to many natural product chemotherapeutic agents.