D-Verapamil downmodulates P170-associated resistance to doxorubicin, daunorubicin and idarubicin

Damiani, D. Doḿınguez; Michieli, Mariagrazia; Michelutti, Angela; Melli, Cristina; Cerno, Michela; Baccarani, Michele

doi:10.1097/00001813-199304000-00007

Cited by 14 publications

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“…Then, cells were incubated at 37˚C and 5% CO 2 for 48 h. Subsequently, the cells were harvested and washed twice with cold PBS, and then divided into two tubes. One tube of cells was used for analysis of cell apoptosis, in which 1x10 6 cells/ml of cell suspension was obtained by adding 5 µl of Annexin V-FITC (BD Biosciences, San Jose, CA, USA) and 200 µl of 1X binding buffer (BD Biosciences). Propidium iodide (10 µl) (Thermo Fisher Scientific, Inc.) was next added and allowed to react in the dark for 30 min.…”

Section: Reverse Transcription-quantitative Polymerase Chain Reactionmentioning

confidence: 99%

“…In previous studies, calcium antagonists such as verapamil (4) and small interfering RNA (siRNA) targeting multidrug resistance protein 1 (MDR1) messenger RNA (mRNA) were observed to modulate MDR1/P-glycoprotein (P-gp)-dependent MDR by downregulating the expression of MDR1 mRNA and P-gp (5). However, calcium antagonists may cause heart failure and hypotension (6), and the clinical benefit of siRNA targeting MDR1 mRNA has not been reported thus far. Therefore, successful reversal of drug resistance still requires new therapeutic strategies or pharmaceuticals.…”

Section: Introductionmentioning

confidence: 99%

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Wip1 gene silencing enhances the chemosensitivity of human colon cancer cells

Xia

et al. 2017

Oncology Letters

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Abstract. Colon cancer is one of the most common cancers in the world. Multidrug resistance is one of the main reasons for failure of therapy in patients with advanced colon cancer. In previous studies, multiple methods were investigated to reverse the multidrug resistance of colon cancer cells. However, to date, no clinical method has been identified to be satisfactory. Therefore, successful reversal of drug resistance in colon cancer cells still requires new therapeutic strategies or pharmaceuticals. Wild-type p53-induced phosphatase (Wip1), a member of the 2C type serine/threonine protein phosphatase family, is closely associated with the p53 gene, which is the most important tumor-suppressor gene. Wip1 was reported to be associated with the chemosensitivity of breast cancer cells. However, the correlation between the expression of Wip1 gene and the chemosensitivity of colon cancer cells has not been reported yet. In the present study, Wip1-811 small interfering RNA (siRNA) targeting Wip1 was investigated to reverse the multidrug resistance of colon cancer cells. The siRNA duplexes were transfected into RKO colon cancer cells. The messenger RNA (mRNA) expression of Wip1 was measured by reverse transcription-quantitative polymerase chain reaction. The protein level of Wip1 was detected by western blotting. The cell viability was measured by MTS assay. The cell apoptosis and cell cycle were analyzed by flow cytometry. Intracellular adriamycin cumulative concentration was determined using flow cytometry. Wip1-811 siRNA efficiently inhibited the expression of Wip1 at the mRNA and protein levels, and enhanced the sensitivity of RKO colon cancer cells towards chemotherapy, which was accompanied by increased cell apoptosis, following the inhibition of Wip1 gene expression. These results indicate that Wip1 gene silencing could enhance the chemosensitivity of colon cancer cells, which may provide a new potential approach for the reversal of multidrug resistance in colon cancer cells.

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Section: Reverse Transcription-quantitative Polymerase Chain Reactionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Wip1 gene silencing enhances the chemosensitivity of human colon cancer cells

Xia

et al. 2017

Oncology Letters

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“…In previous studies, calcium antagonists such as verapamil (5), antisense oligonucleotides (6) and hammerhead ribozymes (7) were found to modulate MDR1/P-gp-dependent MDR by down-regulating the expression of the MDR1 mRNA and P-gp. However, calcium antagonists may cause heart failure and hypotension (8), and the clinical benefit of antisense oligonucleotides and hammerhead ribozymes has not been realized. So successful reversal of drug resistance is still awaiting new therapeutic strategies or pharmaceuticals.…”

Section: Introductionmentioning

confidence: 99%

Specific reversal of MDR1/P-gp-dependent multidrug resistance by RNA interference in colon cancer cells

Xia¹

1994

Oncol Rep

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Abstract. No control cell line was available for previous RNA interference studies on reversal of multidrug resistance (MDR) in colon cancer cells. Here, human COLO 320DM, with HT-29 as the control, colon cancer cell lines were used to investigate the reversal of MDR1/P-gp-dependent MDR by siRNA (#4123 and #4029 MDR1 siRNAs) targeting to MDR1 mRNA. Both siRNAs inhibited expression of MDR1 and P-gp in COLO 320DM. The minimum inhibition concentrations were 5 nmol/l of #4123 and 25 nmol/l of #4029. #4123 MDR1 siRNA took effect in 4, 5 and 6 days at doses of 5, 25 and 100 nmol/l, respectively. Increased cytotoxicity of the antitumor drugs adriamycin and vincristine with increased intracellular adriamycin accumulation accompanied inhibition of MDR1 mRNA and P-gp expression. No such effects were found in the HT-29 control. MDR1 siRNAs specifically reversed the MDR of colon cancer cells demonstrating a possible new approach for treating MDR1/P-gpdependent multidrug resistance. IntroductionColon cancer is the second leading cause of cancer death in the United States (1). Most patients with colon cancer are in its advanced stage by the time of diagnosis (2), so surgery is rarely sufficient treatment. Consequently, chemotherapy is very important in the treatment of colon cancer. However, the effectiveness of chemotherapy is limited because colon cancer cells become drug resistance (3).Classical multiple drug resistance (MDR) in cancer cells is thought to be related to the overexpression of P-glycoprotein (P-gp, MDR1) (4). P-glycoprotein is a 170-kDa transmembrane protein and a member of the ATP-binding cassette transporter superfamily. P-glycoprotein functions as an energydependent efflux pump, thereby resulting in decreased concentrations of intracellular drugs and resistance to the chemotherapeutic effect of these drugs. To improve the effect of chemotherapy in the treatment of colon cancer, one of the major challenges is how to reverse MDR in colon cancer cells. In previous studies, calcium antagonists such as verapamil (5), antisense oligonucleotides (6) and hammerhead ribozymes (7) were found to modulate MDR1/P-gp-dependent MDR by down-regulating the expression of the MDR1 mRNA and P-gp. However, calcium antagonists may cause heart failure and hypotension (8), and the clinical benefit of antisense oligonucleotides and hammerhead ribozymes has not been realized. So successful reversal of drug resistance is still awaiting new therapeutic strategies or pharmaceuticals.A novel means for specific inhibition of a target gene is the use of small interfering RNA (siRNA). These 21-23 nucleotides (nt) long, double-stranded RNA (dsRNA) molecules can direct degradation of eukaryotic mRNAs in a sequence-specific manner (9). This ubiquitous mechanism of gene regulation in plants and animals was designated as RNA interference (RNAi) (10).In this study, we chose the COLO 320DM cell line for our colon cancer model to investigate the reversal of MDR using siRNA. COLO 320DM has been reported to express P-gp and has MDR to many chemothe...

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“…In previous studies, calcium antagonists such as verapamil (6), antisense oligonucleotides (7) and hammerhead ribozymes (8) were found to modulate MDR1/P-gp-dependent MDR by down-regulating the expression of MDR1 mRNA and P-gp. However, calcium antagonists may cause heart failure and hypotension (9), and the clinical benefit of antisense oligonucleotides and hammerhead ribozymes has not been realized. Consequently, it is necessary to develop alternative, less toxic and more efficient strategies or pharmaceuticals to reverse the MDR of cancer cells.…”

Section: Introductionmentioning

confidence: 99%

Stable reversal of multidrug resistance in colon cancer cells by RNA interference targeting the MDR1 gene

Xia

Zhang

Chen³

et al. 2009

Mol Med Rep

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Abstract. Colon cancer is one of the most common cancers in the world. Overexpression of MDR1 mRNA and P-gp is associated with the classic multidrug resistance of colon cancer cells. In our previous study, we reported on the transient specific reversal of MDR1/P-gp-dependent multidrug resistance by RNA interference (RNAi) in colon cancer cells. In this study, RNAi targeting the MDR1 gene stably reversed MDR1/P-gp-dependent multidrug resistance in colon cancer cells. The plasmid vectors pSilencer-#4029, encoding #4029 MDR1 siRNA, and pSilencer-#4123, encoding #4123 MDR1 siRNA, were constructed and then transfected into COLO 320DM, a colon cancer multidrug-resistant cell line. Clone cells were screened by G418 and identified by RT-PCR and Western blot analysis. Cellular viability was measured using the MTT assay. Cell cycle analysis and intracellular adriamycin accumulation were assessed by flow cytometry. MDR1 mRNA and P-gp expression in positive clone cells, those stably transfected with MDR1 siRNA, was inhibited. The IC 50 values of the antitumor drugs were significantly decreased in the positive clones compared to the COLO 320DM parent cell line, and the PI/AI values of positive clones treated with antitumor drugs were significantly decreased compared to the parent cells. In addition, the intracellular adriamycin accumulation of positive clones treated with adriamycin was significantly increased compared with COLO 320DM. This demonstrates that the stable transfection of plasmid vectors encoding MDR1 siRNA can stably reverse the MDR1/P-gp-dependent multidrug resistance of colon cancer cells.

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D-Verapamil downmodulates P170-associated resistance to doxorubicin, daunorubicin and idarubicin

Cited by 14 publications

References 0 publications

Wip1 gene silencing enhances the chemosensitivity of human colon cancer cells

Wip1 gene silencing enhances the chemosensitivity of human colon cancer cells

Specific reversal of MDR1/P-gp-dependent multidrug resistance by RNA interference in colon cancer cells

Stable reversal of multidrug resistance in colon cancer cells by RNA interference targeting the MDR1 gene

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