AIM: To interfere with the activation of nuclear factor-κB(NF-κB) with metformin and explore its effect in reversing multidrug resistance(MDR) of hepatocellular carcinoma(HCC) cells.METHODS: Expression of P-glycopro...AIM: To interfere with the activation of nuclear factor-κB(NF-κB) with metformin and explore its effect in reversing multidrug resistance(MDR) of hepatocellular carcinoma(HCC) cells.METHODS: Expression of P-glycoprotein(P-gp) and NF-κB in human HepG 2 or HepG 2/adriamycin(ADM) cells treated with pC MV-NF-κB-small interference RNA(siR NA) with or without metformin, was analyzed by Western blot or fluorescence quantitative PCR. Cell viability was tested by CCK-8 assay. Cell cycle and apoptosis were measured by flow cytometry and Annexin-V-PE/7-AnnexinV apoptosis detection double staining assay, respectively. RESULTS: P-gp overexpression in HepG 2 and HepG 2/ADM cells was closely related to mdr1 mR NA(3.310 ± 0.154) and NF-κB mR NA(2.580 ± 0.040) expression. NF-κB gene transcription was inhibited by specific siR NA with significant down-regulation of P-gp and enhanced HCC cell chemosensitivity to doxorubicin. After pretreatment with metformin, Hep G2/ADM cells were sensitized to doxorubicin and P-gp was decreased through the NF-κB signaling pathway. The synergistic effect of metformin and NF-κB siR NA were found in HepG 2/ADM cells with regard to proliferation inhibition, cell cycle arrest and inducing cell apoptosis. CONCLUSION: Metformin via silencing NF-κB signaling could effectively reverse MDR of HCC cells by downregulating MDR1/P-gp expression.展开更多
The multidrug resistance P-glycoprotein (P-gp) expression and func-tion in hematopoietic stem/progenitor cells were studied to investigate whether the inhibition of hematopoietic cell P-gp function by multidrug resist...The multidrug resistance P-glycoprotein (P-gp) expression and func-tion in hematopoietic stem/progenitor cells were studied to investigate whether the inhibition of hematopoietic cell P-gp function by multidrug resistance reversal agent increases the cytotoxicity of chemotherapy drugs on the hematopoietic cells.The expression of P-gp on the surface of CD cells from healthy human marrow was examined by flow cytometry. The multidrug resistance reversal agent MS-209 was used to measure the effects of MS-209 on the Rhodamin-123 uptaking o fCD hematopoietic cells. By using methylcellulose semi-solid culture, normal human granulocyte-macrophage clonal formation unit (CFU-GM) was cultured. The changes in CFU-GM inhibitory rate caused by daunorubicin were determined in the presence or absence of MS-2O9. The results showed that the P-gp expression rate of bone marrow CDL cells was 13. 3 %. MS-209 obviously increased the Rhodamin-123 uptake of CD positive cells. The mean inhibitory rate of daunorubicin for CFU-GM was 29. 6 %, but it was increased to 43. 3 % in the presence of MS-209 with the difference being significant (P< 0. 05). It was concluded that hematopoietic cells expressed P-gp protein and possessed active function- MS-209could inhibit the membrane efflux pump and increase the cytotoxicity of chemotherapy drugs to the clonal growth of hematopoeitic stem cells, suggesting the side effects of these drugs on the hematopoietic system should be taken into consideration in the clinical use.展开更多
A hammerhead ribozyme which site-specifically cleaved the GUC position in canon 880 of the mdr1 mRNA was designed. The target site was chosen between the two ATP binding sites, which may be important for the function ...A hammerhead ribozyme which site-specifically cleaved the GUC position in canon 880 of the mdr1 mRNA was designed. The target site was chosen between the two ATP binding sites, which may be important for the function of the P-Gp as an ATP-dependent pump. A DNA sequence encoding the ribozyme gene was then incorporated into a eukaryotic expression vector (pH Apr-1 neo) and transfected into the breast cancer cell line MCF-7/Adr, which is resistant to adriamycin and expresses the MDR phenotype. The ribozyme was stably expressed in the cell line by the RNA dot blotting assay. The result of Northern blot assay showed that the expressed ribozyme could decrease the level of mdrl mRNA expression by 83. 5 %; and the expressed ribozyme could inhibite the formation of p-glycoprotein detected by immuno- cy-tochemistry assay and could reduce the cell’s resistance to adrimycin; this means that the resistant cells were 1 000-fold more resistant than the parental cell line(MCF-7), whereas those cell clones that showed ribozyme expression were only 6-fold more resistant than the parental cell line. These results show that a potentially useful tool is at hand which may inactivate MDR1 mRNA and revert the multidrug resistance phenotype.展开更多
Recently,a large number of tyrosine kinase inhibitors(TKIs) have been developed as anticancer agents.These TKIs can specifically and selectively inhibit tumor cell growth and metastasis by targeting various tyrosine k...Recently,a large number of tyrosine kinase inhibitors(TKIs) have been developed as anticancer agents.These TKIs can specifically and selectively inhibit tumor cell growth and metastasis by targeting various tyrosine kinases and thereby interfering with cellular signaling pathways.The therapeutic potential of TKIs has been hindered by multidrug resistance(MDR),which is commonly caused by overexpression of ATP-binding cassette(ABC) membrane transporters.Interestingly,some TKIs have also been found to reverse MDR by directly inhibiting the function of ABC transporters and enhancing the efficacy of conventional chemotherapeutic drugs.In this review,we discuss ABC transporter-mediated MDR to TKIs and MDR reversal by TKIs.展开更多
Objective The clinical signilicance of exPression of multidrug resistance- associated protein (MRP) in gastric and renal carcinoma was investigated. Methods LSAB immunohistochemistry was performed to detect eopression...Objective The clinical signilicance of exPression of multidrug resistance- associated protein (MRP) in gastric and renal carcinoma was investigated. Methods LSAB immunohistochemistry was performed to detect eopression of MRP in the carcinoma tissues of 52 patients with gastric carcinoma and 20 cases with renal cell carcinoma. Results The positive expression rate of MRP was 38.5% (20/52) in gastric carcinoma tissues, and 60% (12/20) in renal carcinoma tissues. The expression of MRP both on cellular membrane and in cytoplasm was observed, but the expression in cytoplasm (thick granule) was more obvious. The positive expression rates of MRP in advanced gastric and renal carcinoma (Ⅲ orⅣ stage) were 60% (15/25) and 88.90% (8/9) reSPectively, which were higher than those in early lesion (Ⅰ or Ⅱ stage, 18.5% and 36.4% respectively). Furthermore, the patients with positive expression of MRP in gastric carcinoma tissues had shorter mean survival time and lower 5-year survival rate than that with negative eopression of MRP. Conclusion MRP plays an important role in the infiltration and metastasis of gastric and renal carcinoma and might contribute to the intrinsic drug - resistance in both carcinomas.展开更多
OBJECTIVE The aim of the study was to examine the reversal effects of ultrasound （US） on the MDR in HepG2/ADM, a HepG2 cell line resistant to Adriamycin （ADM）, and to study the mechanism of US action.METHODS Using...OBJECTIVE The aim of the study was to examine the reversal effects of ultrasound （US） on the MDR in HepG2/ADM, a HepG2 cell line resistant to Adriamycin （ADM）, and to study the mechanism of US action.METHODS Using the MTT assay, the effects of US on MDR in HepG2/ADR cells were studied. Before and after the treatment with 0.5 W/cm^2 low intensity ultrasound （LIUS）, the expression of the MDR-related genes, mdrl, mrp and lrp was assayed with the reverse transcriptase polymerase chain reaction （RT-PCR） and the levels of their respective protein expression determined by flow cytometry. By using confocal laser scanning microscopy （CLSM）, we examined the intracellular daunorubicin （DNR） distribution, and the effects on the cells of treatment with US or DNR.RESULTS LIUS significantly reversed MDR in HepG2/ADR cells. After treatment with LIUS at 0.5 W/cm^2, chemosensitivity to ADM and DNR increased 3.35-fold and 2.81-fold, respectively. The reversal activity by LIUS plus verapamil （VER） was stronger than with either US or VER alone. After treatment with 0.5 W/cm^2, the expression of both the MDR1 and the MRP mRNA genes began to decline （P 〈 0.01 and P 〈 0.05, respectively）; the expression of LRP showed no significant changes. Changes in the expression of the P-glycoprotein （P-gp） and MRP were similar to those of their mRNA expressions. Results of the CLSM showed that administration of US （0. 5 W/cm^2） or VER （15.7 uM） with DNR to HepGa/ADM cells showed a significant change in the distribution of DNR in the cells.CONCLUSION Our results show that LIUS can reverse MDR. The reversal effects are stronger than those of either US or VER alone, when combined with VER administration. As LIUS is noninvasive causing no toxicity, it might have potential for clinical application. The reversal mechanism needs further study.展开更多
Eleven biogenetically related polyprenylated acylphloroglucinols(PPAPs),including four novel skeletons(1-4)and five new com-pounds(5-9),were isolated from the flowers of Hypericum monogynum.Hypermonones A-D(1-4)repres...Eleven biogenetically related polyprenylated acylphloroglucinols(PPAPs),including four novel skeletons(1-4)and five new com-pounds(5-9),were isolated from the flowers of Hypericum monogynum.Hypermonones A-D(1-4)represented the first example of a unique dilactone structure containing carbonyl bonded single 5-lactone and tricyclic γ-lactone moieties.Their structures were elucidated by NMR analysis,X-ray crystallography,and ECD calculations.Moreover,we revised the structure of hyperibrin B to hy perm on one I(9)via NMR an alysis,a qua ntum computational chemistry method,and hypothetic bios yn thetic con siderations.Three compounds(5,6,and 9)with significant MDR reversal activity(RF ranging from 61 to 223)were superior to the positive control verapamil(MCF-7/ADR,RF:53;HepG2/ADRz RF:124).Mechanism study for compound 5 indicated that this compound could inhibit the function of P-gp tran sport rather tha n its expressi on,and the possible recog nition mechanism betwee n compo und 5 and P-gp was predicted by molecular docking.展开更多
Multidrug resistance remains a serious clinical problem in the successful therapy of malignant diseases. It occurs in cultured tumor cell lines, as well as in human cancers. Therefore, it is critical to develop novel ...Multidrug resistance remains a serious clinical problem in the successful therapy of malignant diseases. It occurs in cultured tumor cell lines, as well as in human cancers. Therefore, it is critical to develop novel anticancer drugs with multidrug-resistance modulating potential to increase the survival rate of leukemia patients. Plant-derived natural products have been used for the treatment of various diseases for thousands of years. This review summarizes the anticancer and multidrug-resistance reversing properties of the extracts and bioactive compounds from traditional medicinal plants in different leukemia cell lines. Further mechanistic studies will pave the road to establish the anticancer potential of plant-derived natural compounds.展开更多
Our recent studies demonstrated that the natural product nobiletin(NOB)served as a promising multidrug resistance(MDR)reversal agent and improved the effectiveness of cancer chemotherapy in vitro.However,low aqueous s...Our recent studies demonstrated that the natural product nobiletin(NOB)served as a promising multidrug resistance(MDR)reversal agent and improved the effectiveness of cancer chemotherapy in vitro.However,low aqueous solubility and difficulty in total synthesis limited its application as a therapeutic agent.To tackle these challenges,NOB was synthesized in a high yield by a concise route of six steps and fourteen derivatives were synthesized with remarkable solubility and efficacy.All the compounds showed improved sensitivity to paclitaxel(PTX)in P-glycoprotein(P-gp)overexpressing MDR cancer cells.Among them,compound 29 d exhibited water solubility 280-fold higher than NOB.A drug-resistance A549/T xenograft model showed that 29 d,at a dose of 50 mg/kg co-administered with PTX(15 mg/kg),inhibited tumor growth more effective than NOB and remarkably increased PTX concentration in the tumors via P-gp inhibition.Moreover,Western blot experiments revealed that 29 d inhibited expression of NRF2,phosphorylated ERK and AKT in MDR cancer cells,thus implying 29 d of multiple mechanisms to reverse MDR in lung cancer.展开更多
基金Supported by Projects of Jiangsu Elitist Peak in Six Fields,Nos.2013-WSN-078,2013-WSW-011,and 2014-YY-028the QingL an Program of Jiangsu Higher Education,the Youth Science Foundation of Nantong Health Department,No.WQ2014005the International Science and Technology Cooperation Program,No.2013DFA32150
文摘AIM: To interfere with the activation of nuclear factor-κB(NF-κB) with metformin and explore its effect in reversing multidrug resistance(MDR) of hepatocellular carcinoma(HCC) cells.METHODS: Expression of P-glycoprotein(P-gp) and NF-κB in human HepG 2 or HepG 2/adriamycin(ADM) cells treated with pC MV-NF-κB-small interference RNA(siR NA) with or without metformin, was analyzed by Western blot or fluorescence quantitative PCR. Cell viability was tested by CCK-8 assay. Cell cycle and apoptosis were measured by flow cytometry and Annexin-V-PE/7-AnnexinV apoptosis detection double staining assay, respectively. RESULTS: P-gp overexpression in HepG 2 and HepG 2/ADM cells was closely related to mdr1 mR NA(3.310 ± 0.154) and NF-κB mR NA(2.580 ± 0.040) expression. NF-κB gene transcription was inhibited by specific siR NA with significant down-regulation of P-gp and enhanced HCC cell chemosensitivity to doxorubicin. After pretreatment with metformin, Hep G2/ADM cells were sensitized to doxorubicin and P-gp was decreased through the NF-κB signaling pathway. The synergistic effect of metformin and NF-κB siR NA were found in HepG 2/ADM cells with regard to proliferation inhibition, cell cycle arrest and inducing cell apoptosis. CONCLUSION: Metformin via silencing NF-κB signaling could effectively reverse MDR of HCC cells by downregulating MDR1/P-gp expression.
文摘The multidrug resistance P-glycoprotein (P-gp) expression and func-tion in hematopoietic stem/progenitor cells were studied to investigate whether the inhibition of hematopoietic cell P-gp function by multidrug resistance reversal agent increases the cytotoxicity of chemotherapy drugs on the hematopoietic cells.The expression of P-gp on the surface of CD cells from healthy human marrow was examined by flow cytometry. The multidrug resistance reversal agent MS-209 was used to measure the effects of MS-209 on the Rhodamin-123 uptaking o fCD hematopoietic cells. By using methylcellulose semi-solid culture, normal human granulocyte-macrophage clonal formation unit (CFU-GM) was cultured. The changes in CFU-GM inhibitory rate caused by daunorubicin were determined in the presence or absence of MS-2O9. The results showed that the P-gp expression rate of bone marrow CDL cells was 13. 3 %. MS-209 obviously increased the Rhodamin-123 uptake of CD positive cells. The mean inhibitory rate of daunorubicin for CFU-GM was 29. 6 %, but it was increased to 43. 3 % in the presence of MS-209 with the difference being significant (P< 0. 05). It was concluded that hematopoietic cells expressed P-gp protein and possessed active function- MS-209could inhibit the membrane efflux pump and increase the cytotoxicity of chemotherapy drugs to the clonal growth of hematopoeitic stem cells, suggesting the side effects of these drugs on the hematopoietic system should be taken into consideration in the clinical use.
基金This research was supported by the National Natural ScienceYouth Grant.
文摘A hammerhead ribozyme which site-specifically cleaved the GUC position in canon 880 of the mdr1 mRNA was designed. The target site was chosen between the two ATP binding sites, which may be important for the function of the P-Gp as an ATP-dependent pump. A DNA sequence encoding the ribozyme gene was then incorporated into a eukaryotic expression vector (pH Apr-1 neo) and transfected into the breast cancer cell line MCF-7/Adr, which is resistant to adriamycin and expresses the MDR phenotype. The ribozyme was stably expressed in the cell line by the RNA dot blotting assay. The result of Northern blot assay showed that the expressed ribozyme could decrease the level of mdrl mRNA expression by 83. 5 %; and the expressed ribozyme could inhibite the formation of p-glycoprotein detected by immuno- cy-tochemistry assay and could reduce the cell’s resistance to adrimycin; this means that the resistant cells were 1 000-fold more resistant than the parental cell line(MCF-7), whereas those cell clones that showed ribozyme expression were only 6-fold more resistant than the parental cell line. These results show that a potentially useful tool is at hand which may inactivate MDR1 mRNA and revert the multidrug resistance phenotype.
基金supported by grantsfrom the National Natural Science Foundation of China(No. 30873097)Research Fund for the Doctoral Program of Higher Education of China (No.20092104110020)Science and Technology Planning Project of Liaoning Province,China (No.2010225001)
文摘Recently,a large number of tyrosine kinase inhibitors(TKIs) have been developed as anticancer agents.These TKIs can specifically and selectively inhibit tumor cell growth and metastasis by targeting various tyrosine kinases and thereby interfering with cellular signaling pathways.The therapeutic potential of TKIs has been hindered by multidrug resistance(MDR),which is commonly caused by overexpression of ATP-binding cassette(ABC) membrane transporters.Interestingly,some TKIs have also been found to reverse MDR by directly inhibiting the function of ABC transporters and enhancing the efficacy of conventional chemotherapeutic drugs.In this review,we discuss ABC transporter-mediated MDR to TKIs and MDR reversal by TKIs.
文摘Objective The clinical signilicance of exPression of multidrug resistance- associated protein (MRP) in gastric and renal carcinoma was investigated. Methods LSAB immunohistochemistry was performed to detect eopression of MRP in the carcinoma tissues of 52 patients with gastric carcinoma and 20 cases with renal cell carcinoma. Results The positive expression rate of MRP was 38.5% (20/52) in gastric carcinoma tissues, and 60% (12/20) in renal carcinoma tissues. The expression of MRP both on cellular membrane and in cytoplasm was observed, but the expression in cytoplasm (thick granule) was more obvious. The positive expression rates of MRP in advanced gastric and renal carcinoma (Ⅲ orⅣ stage) were 60% (15/25) and 88.90% (8/9) reSPectively, which were higher than those in early lesion (Ⅰ or Ⅱ stage, 18.5% and 36.4% respectively). Furthermore, the patients with positive expression of MRP in gastric carcinoma tissues had shorter mean survival time and lower 5-year survival rate than that with negative eopression of MRP. Conclusion MRP plays an important role in the infiltration and metastasis of gastric and renal carcinoma and might contribute to the intrinsic drug - resistance in both carcinomas.
基金a grant from National Natural Science Foundation of China (No.30200060)
文摘OBJECTIVE The aim of the study was to examine the reversal effects of ultrasound （US） on the MDR in HepG2/ADM, a HepG2 cell line resistant to Adriamycin （ADM）, and to study the mechanism of US action.METHODS Using the MTT assay, the effects of US on MDR in HepG2/ADR cells were studied. Before and after the treatment with 0.5 W/cm^2 low intensity ultrasound （LIUS）, the expression of the MDR-related genes, mdrl, mrp and lrp was assayed with the reverse transcriptase polymerase chain reaction （RT-PCR） and the levels of their respective protein expression determined by flow cytometry. By using confocal laser scanning microscopy （CLSM）, we examined the intracellular daunorubicin （DNR） distribution, and the effects on the cells of treatment with US or DNR.RESULTS LIUS significantly reversed MDR in HepG2/ADR cells. After treatment with LIUS at 0.5 W/cm^2, chemosensitivity to ADM and DNR increased 3.35-fold and 2.81-fold, respectively. The reversal activity by LIUS plus verapamil （VER） was stronger than with either US or VER alone. After treatment with 0.5 W/cm^2, the expression of both the MDR1 and the MRP mRNA genes began to decline （P 〈 0.01 and P 〈 0.05, respectively）; the expression of LRP showed no significant changes. Changes in the expression of the P-glycoprotein （P-gp） and MRP were similar to those of their mRNA expressions. Results of the CLSM showed that administration of US （0. 5 W/cm^2） or VER （15.7 uM） with DNR to HepGa/ADM cells showed a significant change in the distribution of DNR in the cells.CONCLUSION Our results show that LIUS can reverse MDR. The reversal effects are stronger than those of either US or VER alone, when combined with VER administration. As LIUS is noninvasive causing no toxicity, it might have potential for clinical application. The reversal mechanism needs further study.
基金supported by the National Natural Science Foundation of China(Nos.U1812403,81872772,and 81960546)the Scie nee and Tech no logy Departme nt of Guizhou Province(Nos.QKH 2020-1Z076,QKHZC[2020]4Y203z QKHJC[2018]1409,QKHZC[2019]2762,and QKHPTRC[2020]5008)+3 种基金the High-level Innovative Talents in Guizhou Provinee(Thousand Levels of Talent for Chunmao Yuan in 2018)the"Light of the West"Talent Cultivation Program of Chinese Academy of Sciences for Chunmao Yuan(No.RZ[2020]82)the 100 Leading Talents of Guizhou Provinee(fund for Y.M.L)the Guizhou Provincial Engineering Research Center for Natural Drugs.
文摘Eleven biogenetically related polyprenylated acylphloroglucinols(PPAPs),including four novel skeletons(1-4)and five new com-pounds(5-9),were isolated from the flowers of Hypericum monogynum.Hypermonones A-D(1-4)represented the first example of a unique dilactone structure containing carbonyl bonded single 5-lactone and tricyclic γ-lactone moieties.Their structures were elucidated by NMR analysis,X-ray crystallography,and ECD calculations.Moreover,we revised the structure of hyperibrin B to hy perm on one I(9)via NMR an alysis,a qua ntum computational chemistry method,and hypothetic bios yn thetic con siderations.Three compounds(5,6,and 9)with significant MDR reversal activity(RF ranging from 61 to 223)were superior to the positive control verapamil(MCF-7/ADR,RF:53;HepG2/ADRz RF:124).Mechanism study for compound 5 indicated that this compound could inhibit the function of P-gp tran sport rather tha n its expressi on,and the possible recog nition mechanism betwee n compo und 5 and P-gp was predicted by molecular docking.
基金supported by the National Natural Science Foundation of P.R.China(Nos.81170492,81370673)National High Technology Research and Development Program 863 of P.R.China(No.2012AA022703)+2 种基金National Key Basic Research Program 973 of P.R.China(No.2010CB732404)Key Medical Projects of Jiangsu Province(No.BL2014078)Key Discipline of Jiangsu Province(2011-2015)
文摘Multidrug resistance remains a serious clinical problem in the successful therapy of malignant diseases. It occurs in cultured tumor cell lines, as well as in human cancers. Therefore, it is critical to develop novel anticancer drugs with multidrug-resistance modulating potential to increase the survival rate of leukemia patients. Plant-derived natural products have been used for the treatment of various diseases for thousands of years. This review summarizes the anticancer and multidrug-resistance reversing properties of the extracts and bioactive compounds from traditional medicinal plants in different leukemia cell lines. Further mechanistic studies will pave the road to establish the anticancer potential of plant-derived natural compounds.
基金supported by National Key R&D Program of China(2017YFB0202600)Macao Science and Technology Development Fund,Macao Special Administrative Region(003/2017/A1to Ying Xie,China)+1 种基金National Natural Science Foundation of China(21572279,21877134,81602955 and 81703341)Guangdong Province Higher Vocational Colleges&Schools Pearl River Scholar Funded Scheme(2016,China).
文摘Our recent studies demonstrated that the natural product nobiletin(NOB)served as a promising multidrug resistance(MDR)reversal agent and improved the effectiveness of cancer chemotherapy in vitro.However,low aqueous solubility and difficulty in total synthesis limited its application as a therapeutic agent.To tackle these challenges,NOB was synthesized in a high yield by a concise route of six steps and fourteen derivatives were synthesized with remarkable solubility and efficacy.All the compounds showed improved sensitivity to paclitaxel(PTX)in P-glycoprotein(P-gp)overexpressing MDR cancer cells.Among them,compound 29 d exhibited water solubility 280-fold higher than NOB.A drug-resistance A549/T xenograft model showed that 29 d,at a dose of 50 mg/kg co-administered with PTX(15 mg/kg),inhibited tumor growth more effective than NOB and remarkably increased PTX concentration in the tumors via P-gp inhibition.Moreover,Western blot experiments revealed that 29 d inhibited expression of NRF2,phosphorylated ERK and AKT in MDR cancer cells,thus implying 29 d of multiple mechanisms to reverse MDR in lung cancer.
