Currently, chemoresistance seriously attenuates the curative outcome of liver cancer. The purpose of our work was to investigate the influence of 6-shogaol on the inhibition of 5-fluorouracil (5-FU) in liver cancer. The cell viability of cancer cells was determined by MTT assay. Liver cancer cell apoptosis and the cell cycle were examined utilizing flow cytometry. Moreover, qRT-PCR and western blotting was used to analyse the mRNA and protein expression levels, respectively. Immunohistochemistry assays were used to examine multidrug resistance protein 1 (MRP1) expression in tumour tissues. In liver cancer cells, we found that 6-shogaol-5-FU combination treatment inhibited cell viability, facilitated G0/G1 cell cycle arrest, and accelerated apoptosis compared with 6-shogaol or 5-FU treatment alone. In cancer cells cotreated with 6-shogaol and 5-FU, AKT/mTOR pathway- and cell cycle-related protein expression levels were inhibited, and MRP1 expression was downregulated. AKT activation or MRP1 increase reversed the influence of combination treatment on liver cancer cell viability, apoptosis and cell cycle arrest. The inhibition of AKT activation to the anticancer effect of 6-shogaol-5-FU could be reversed by MRP1 silencing. Moreover, our results showed that 6-shogaol-5-FU combination treatment notably inhibited tumour growth in vivo. In summary, our data demonstrated that 6-shogaol contributed to the curative outcome of 5-FU in liver cancer by inhibiting the AKT/mTOR/MRP1 signalling pathway.
ATP Binding Cassette Transporter, Subfamily B, Member 1 ; Apoptosis ; Catechols ; Cell Cycle ; Cell Cycle Checkpoints ; Cell Line, Tumor ; Cell Proliferation ; Drug Resistance, Neoplasm ; Fluorouracil/pharmacology* ; Humans ; Liver Neoplasms/genetics* ; Multidrug Resistance-Associated Proteins ; Proto-Oncogene Proteins c-akt/metabolism* ; TOR Serine-Threonine Kinases/metabolism*

Multidrug resistance (MDR) is one of the major obstacles in cancer chemotherapy. Our previous study has shown that icariin could reverse MDR in MG-63 doxorubicin-resistant (MG-63/DOX) cells. It is reported that icariin is usually metabolized to icariside II and icaritin. Herein, we investigated the effects of icariin, icariside II, and icaritin (ICT) on reversing MDR in MG-63/DOX cells. Among these compounds, ICT exhibited strongest effect and showed no obvious cytotoxicity effect on both MG-63 and MG-63/DOX cells ranging from 1 to 10 μmol·L. Furthermore, ICT increased accumulation of rhodamine 123 and 6-carboxyfluorescein diacetate and enhanced DOX-induced apoptosis in MG-63/DOX cells in a dose-dependent manner. Further studies demonstrated that ICT decreased the mRNA and protein levels of multidrug resistance protein 1 (MDR1) and multidrug resistance-associated protein 1 (MRP1). We also verified that blockade of STAT3 phosphorylation was involved in the reversal effect of multidrug resistance in MG-63/DOX cells. Taken together, these results indicated that ICT may be a potential candidate in chemotherapy for osteosarcoma.
ATP Binding Cassette Transporter, Subfamily B ; drug effects ; genetics ; metabolism ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Doxorubicin ; metabolism ; pharmacology ; toxicity ; Drug Resistance, Multiple ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Flavonoids ; pharmacology ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Multidrug Resistance-Associated Proteins ; drug effects ; genetics ; metabolism ; Osteosarcoma ; drug therapy ; metabolism ; pathology ; Phosphorylation ; drug effects ; Rhodamine 123 ; metabolism ; STAT3 Transcription Factor ; antagonists & inhibitors ; metabolism ; Triterpenes ; pharmacology

BACKGROUNDPlacental multidrug resistance-associated protein 2 (MRP2), encoded by ABCC2 gene in human, plays a significant role in regulating drugs' transplacental transfer rates. Studies on placental MRP2 regulation could provide more therapeutic targets for individualized and safe pharmacotherapy during pregnancy. Currently, the roles of epigenetic mechanisms in regulating placental drug transporters are still unclear. This study aimed to investigate the effect of histone deacetylases (HDACs) inhibition on MRP2 expression in the placental trophoblast cell line and to explore whether HDAC1/2/3 are preliminarily involved in this process.

METHODSThe human choriocarcinoma-derived trophoblast cell line (Bewo cells) was treated with the HDAC inhibitors-trichostatin A (TSA) at different concentration gradients of 0.5, 1.0, 3.0, and 5.0 μmol/L. Cells were harvested after 24 and 48 h treatment. Small interfering RNA (siRNA) specific for HDAC1/HDAC2/HDAC3 or control siRNA was transfected into cells. Total HDAC activity was detected by colorimetric assay kits. HDAC1/2/3/ABCC2 messenger RNA (mRNA) and protein expressions were determined by real-time quantitative polymerase chain reaction and Western-blot analysis, respectively. Immunofluorescence for MRP2 protein expression was visualized and assessed using an immunofluorescence microscopy and ImageJ software, respectively.

RESULTSTSA could inhibit total HDAC activity and HDAC1/2/3 expression in company with increase of MRP2 expression in Bewo cells. Reduction of HDAC1 protein level was noted after 24 h of TSA incubation at 1.0, 3.0, and 5.0 μmol/L (vs. vehicle group, all P < 0.001), accompanied with dose-dependent induction of MRP2 expression (P = 0.045 for 1.0 μmol/L, P = 0.001 for 3.0 μmol/L, and P < 0.001 for 5.0 μmol/L), whereas no significant differences in MRP2 expression were noted after HDAC2/3 silencing. Fluorescent micrograph images of MRP2 protein were expressed on the cell membrane. The fluorescent intensities of MRP2 in the control, HDAC2, and HDAC3 siRNA-transfected cells were week, and no significant differences were noticed among these three groups (all P > 0.05). However, MRP2 expression was remarkably elevated in HDAC1 siRNA-transfected cells, which displayed an almost 3.19-fold changes in comparison with the control siRNA-transfected cells (P < 0.001).

CONCLUSIONSHDACs inhibition could up-regulate placental MRP2 expression in vitro, and HDAC1 was probably to be involved in this process.

Cell Line ; Histone Deacetylase 1 ; metabolism ; Histone Deacetylase 2 ; metabolism ; Histone Deacetylase Inhibitors ; pharmacology ; Histone Deacetylases ; metabolism ; Humans ; Hydroxamic Acids ; pharmacology ; Microscopy, Fluorescence ; Multidrug Resistance-Associated Proteins ; genetics ; metabolism ; RNA, Messenger ; Trophoblasts ; cytology ; metabolism

Amino Acid Substitution ; Drug Resistance, Multiple, Bacterial ; physiology ; Escherichia coli ; physiology ; Escherichia coli Proteins ; genetics ; metabolism ; Membrane Potentials ; physiology ; Models, Biological ; Multidrug Resistance-Associated Proteins ; genetics ; metabolism ; Mutation, Missense

OBJECTIVETo study the effect of Zhusha Anshen pill, cinnabar, HgS, HgCl2 and MeHg on the gene expression of renal transporters in mice.

METHODHealthy male mice were given equivalent physiological saline, Zhusha Anshen pill (1.8 g · kg(-1), containing 0.17 g · kg(-1) of mercury), cinnabar (0.2 g · kg(-1), containing 1.7 g · kg(-1) of mercury), high dose cinnabar (2 g · kg(-1), containing 1.7 g · kg(-1) of mercury), HgS (0.2 g · kg(-1), containing 0.17 g · kg(-1) of mercury), HgCl2 (0.032 g · kg(-1), containing 0. 024 g · kg(-1) of mercury), MeHg (0.026 g · kg(-1), containing 0.024 g · kg(-1) of mercury), once daily, for 30 d, measuring body mass gain. 30 days later, the mice were sacrificed. The mercury accumulation in kidneys was detected with atomic fluorescence spectrometer. Expressions of Oat1, Oat2, Oat3, Mrp2, Mrp4, Urat1 were detected with RT-PCR.

RESULTCompared with the normal control group, a significant accumulation of Hg in kidney in HgCl2 and MeHg groups was observed (P <0.05), but these changes were not found in other groups. Compared with normal control group, mRNA expressions of Oat1 and Oat2 were evidently lower in HgCl2 and MeHg groups, but mRNA expressions of Mrp2 were apparently higher in HgCl2 group (P <0.05), mRNA expression of Mrp4 was significant higher in HgCl2 and MeHg groups, and mRNA expression of Urat1 was apparently lower in MeHg group.

CONCLUSIONHgCl2 and MeHg groups show significant difference from the normal group in mercury accumulation in kidneys and gene expression of kidney transporters, but with no difference between other groups and the normal group. Compared with HgCl2 and MeHg, cinnabar and its compounds could cause lower renal toxicity to mice.

Animals ; Carrier Proteins ; genetics ; Drugs, Chinese Herbal ; toxicity ; Gene Expression ; drug effects ; Kidney ; drug effects ; metabolism ; Male ; Mercuric Chloride ; toxicity ; Mercury Compounds ; toxicity ; Methylmercury Compounds ; toxicity ; Mice ; Multidrug Resistance-Associated Proteins ; genetics ; Organic Anion Transport Protein 1 ; genetics ; Organic Anion Transporters, Sodium-Independent ; genetics

OBJECTIVE: This study aimed to explore the relationship among expression of Survivin and MRP and drug resistance in NPC. METHOD: Expression of Survivin were detected by immunohistochemistry method in 45 cases of NPC and 24 cases of normal mucous membrane of nasopharynx (NMMN). The relationship between expression of Survivin and pathological factors in NPC were analysized. Expression of Survivin and MRP were detected in 31 patients of NPC with paclitaxel resistance and 20 patients of NPC without paclitaxel resistance. The relation- ship among the expression of Survivin or MRP and paclitaxel resistance in NPC were analysized. The paclitaxel resistance cell line, 5-8F-PTX(+); was established by a step-increased method. The expression of Survivin and MRP were detected by western blot in 5-8F-PTX(+) and 5-8F. RESULT: The positive were 71. 1% (32/45) in NPC and 8.33% (2/24) in NMMN. And there were significantly differences between them (P < .05). There were relationship among expression of Survivin and differentiation degree, lymph node metastasis, distant metastasis, and clinic stages of NPC. The positive were 75.9% (31/39) in moderately differentiated NPC and 16.7% (1/6) in lowly differentiated NPC, respectively. There were significantly differences between them (P < 0.05). The positive of Survivin were 83.9% (26/31) in NPC patients with paclitaxel resistance and 45.0% (9/20) in NPC patients without Paclitaxel resistance, respectively. There were significantly differences between them (P < 0.05). The positive of MRP were 87.1% (27/31) in NPC patients with paclitaxel resistance and 40.0% (8/20) in NPC patients without paclitaxel resistance, respectively. There were significantly differences between them (P < 0.05). There were positive correlation between the expression of Survivin and MRP in NPC patients with Paclitaxel resistance. The expression of Survivin and MRP were higher in 5-8F-PTX(+) than in 5-8F. The IC50 of paclitaxel, cDDP, 5-FU and Vincristine were significantly higher in 5-8F-PTX(+) than in 5-8F. CONCLUSION There were relationship among the expression of Survivin and difference, metastasis and TNM stages of NPC. Survivin may serves as a molecular marker for development and progress in NPC. There were relationship among the high expression of Survivin and MRP and increasing of drug resistance in NPC.
Antineoplastic Agents ; pharmacology ; Carcinoma ; Cisplatin ; Drug Resistance, Neoplasm ; Fluorouracil ; Humans ; Immunohistochemistry ; Inhibitor of Apoptosis Proteins ; genetics ; metabolism ; Lymphatic Metastasis ; Multidrug Resistance-Associated Proteins ; genetics ; metabolism ; Nasopharyngeal Carcinoma ; Nasopharyngeal Neoplasms ; genetics ; metabolism ; Nasopharynx ; metabolism ; Paclitaxel ; pharmacology ; Survivin ; Vincristine

OBJECTIVETo investigate the correlation between miR-221 and epithelial-mesenchymal transition (EMT) in drug-resistant glioma cells.

METHODSThe expression levels of miR-221, PTEN, p-Akt, E-cadherin, vimentin, and MRP1 were quantitatively analyzed in Z1 cells (primary drug-resistant cells), Z2 cells (drug-sensitive cells) and Z2-BCNU cells (drug-resistant cells) using fluorescent real-time PCR and Western blotting.

RESULTSThe expression levels of PTEN were significantly increased in Z2 cells compared with Z1 and Z2-BCNU cells which overexpressed miR-221 and vimentin. The expression levels of vimentin, p-Akt and MRP1 were significantly decreased in Z2 cells overexpressing E-cadherin.

CONCLUSIONMiR-221 regulates the expression of EMT-related genes through down-regulation of PTEN and activation of PI3-K/Akt signaling.

Cadherins ; metabolism ; Cell Line, Tumor ; Drug Resistance, Neoplasm ; Epithelial-Mesenchymal Transition ; Gene Expression Regulation, Neoplastic ; Humans ; MicroRNAs ; genetics ; metabolism ; Multidrug Resistance-Associated Proteins ; metabolism ; PTEN Phosphohydrolase ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction ; Vimentin ; metabolism

OBJECTIVETo investigate the effect of tetrandrine (TET) on zinc finger protein 139 (ZNF139) and multidrug resistance (MDR) of human gastric carcinoma cell lines and possible mechanisms.

METHODSCultured SGC7901 and SGC7901/ADR were treated with TET (0.5, 1.0, 1.5, 2.0, and 2.5 microg/mL), then inhibition rates were measured by MTT assay in vitro. The expressions of ZNF139, MRP-1, MDR1, and GST-pi were detected by RT-PCR. The correlation between ZNF139 and each multidrug resistance factor was analyzed using Spearman correlation analysis, and the coefficient correlation was calculated.

RESULTSThe inhibition rate of TET (< or = 2.0 microg/mL) for SGC7901 and SGC7901/ADR was less than 10% with MTT assay. Expressions of ZNF139, MRP-1, MDR1, and GST-pi mRNA were higher in SGC7901/ADR than in SGC7901 (all P < 0.05). The expressions of ZNF139, MRP-1, MDR1, and GST--pi were down-regulated in SGC7901/ADR cells efficiently (all P < 0.01). Positive correlation existed between ZNF139 and MRP-1, ZNF139 and MDR1 before treated by TET in SGC7901/ADR, and this relationship also existed in SGC7901/ADR cells after treated by TET (all P < 0.05).

CONCLUSIONTET could achieve MDR reversion in gastric cancer cells by down-regulating the expression of ZNF139, MRP-1, and MDR1.

ATP Binding Cassette Transporter, Sub-Family B ; metabolism ; Benzylisoquinolines ; pharmacology ; Cell Line, Tumor ; Drug Resistance, Multiple ; drug effects ; genetics ; Drug Resistance, Neoplasm ; drug effects ; genetics ; Humans ; Kruppel-Like Transcription Factors ; metabolism ; Multidrug Resistance-Associated Proteins ; metabolism ; Stomach Neoplasms ; metabolism ; Zinc Fingers ; genetics

Breast Neoplasms ; metabolism ; Female ; Humans ; Multidrug Resistance-Associated Proteins ; genetics ; metabolism ; Receptor, Epidermal Growth Factor ; metabolism ; Receptors, Progesterone ; metabolism

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can induce drug transporter genes such as the ATP-binding cassette G member 2 (ABCG2), which contributes to multidrug resistance. We investigated the effect of TCDD pretreatment on drug transporters induction from cancer cells of various origins. Cell viabilities after treatment of cisplatin were measured to evaluate acquiring cisplatin resistance by TCDD. Acquring cisplatin resistance was found only in cisplatin senstivie cancer cells including gastric SNU601, colon LS180, brain CRT-MG and lymphoma Jurkat cells which showed a significant increase in cell viability after combined treatment with TCDD and cisplatin. High increase of ABCG2 gene expression was found in SNU601 and LS180 cells with a mild increase in the expression of the ABCC3, ABCC5,and SLC29A2 genes in SNU601 cells, and of major vault protein (MVP) in LS180 cells. The AhR inhibitor kaempferol suppressed the upregulation of ABCG2 expression and reversed the TCDD-induced increase in cell viability in LS180 cells. However, in CRT-MG cells, other transporter genes including ABCC1, ABCC5, ABCA3, ABCA2, ABCB4, ABCG1, and SLC29A1 were up-regulated. These findings suggested the acquiring cisplatin resistance by TCDD associated with cancer cell-type-specific induction of drug transporters.
ATP-Binding Cassette Transporters/genetics/*metabolism ; Cell Line, Tumor ; Cell Survival/drug effects ; Cisplatin/*pharmacology ; Drug Resistance, Neoplasm/drug effects ; Equilibrative-Nucleoside Transporter 2/genetics/metabolism ; Humans ; Jurkat Cells ; K562 Cells ; Kaempferols/pharmacology ; Multidrug Resistance-Associated Proteins/genetics/metabolism ; Neoplasm Proteins/genetics/*metabolism ; RNA, Messenger/metabolism ; Receptors, Aryl Hydrocarbon/metabolism ; Tetrachlorodibenzodioxin/*pharmacology ; Up-Regulation/*drug effects ; Vault Ribonucleoprotein Particles/genetics/metabolism