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

OBJECTIVETo investigate whether SIS3, a specific inhibitor of Smad3 phosphorylation, can reverse the stemness of multidrug-resistant(MDR) hepatocellular carcinoma cells.

METHODSMDR HCC Huh7.5.1/ADM cell lines were developed by exposing parental cells to stepwise increasing concentrations of ADM. CCK-8 assay was used to determine the cellular sensitivity of various anticancer drugs. Flow cytometry (FCM) was used to analyze the expression level of cancer stem cell marker CD133. Clone formation assay and mouse subcutaneous xenograft tumors were used to investigate the tumorigenicity in vitro and in vivo. Western blotting (WB) was used to analyze the changes of expressions of CD133, Smad3, Bcl-2, Bax and p-Smad3 in different conditions.

RESULTSADM treatment of HCC cells in vitro resulted in a development of subline, Huh7.5.1/ADM cells, with CSC phenotypes: stable MDR phenotype (besides ADMc Huh7.5.1/ADM cells were also more resistant to some other anticancer drugs including VCR, MMC and CTX ) (IC50: 0.215 ± 0.018 vs. 0.123 ± 0.004, 0.145 ± 0.009 vs. 0.014 ± 0.002, 1.021 ± 0.119 vs. 0.071 ± 0.006, 27.007 ± 1.606 vs. 1.919 ± 0.032) (unit: µg/ml) (P<0.05). Huh7.5.1/ADM cells enriched the cancer stem-like cell fraction (CD133-positive subpopulation) (76.06 ± 2.948% vs. 25.38 ± 4.349%) (P<0.05), had stronger tumorigenicity in vivo and colony formation ability, and activated the Smad3 activity. Inhibition of Smad3 activity by SIS3 decreased stemness of the Huh7.5.1/ADM cells: CD133-positive subpopulation (48.49 ± 2.304% vs. 76.06 ± 2.948%) (P<0.05); ADM IC50: (0.112 ± 0.019 vs. 0.215 ± 0.018), VCR IC50 (0.065 ± 0.013 vs. 0.145±0.009), MMC IC₅₀ (0.749 ± 0.121 vs. 1.021 ± 0.119), CTX IC50 (10.576 ± 1.248 vs. 27.007 ± 1.606) (unit: µg/ml) (P<0.05), and decreased tumorigenicity and colony formation ability.

CONCLUSIONSIS3 as a specific inhibitor of Smad3 signal is involved in the stemness of multidrug resistant hepatocellular carcinoma cells.

AC133 Antigen ; Animals ; Antibiotics, Antineoplastic ; pharmacology ; Antigens, CD ; metabolism ; Carcinoma, Hepatocellular ; drug therapy ; metabolism ; pathology ; Doxorubicin ; pharmacology ; Drug Resistance, Neoplasm ; Glycoproteins ; metabolism ; Heterografts ; Humans ; Isoquinolines ; pharmacology ; Liver Neoplasms ; drug therapy ; metabolism ; pathology ; Mice ; Neoplasm Proteins ; metabolism ; Neoplastic Stem Cells ; drug effects ; Peptides ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Pyridines ; pharmacology ; Pyrroles ; pharmacology ; Smad3 Protein ; antagonists & inhibitors ; metabolism ; Tumor Stem Cell Assay ; bcl-2-Associated X Protein ; metabolism

Angiotensin receptor blockers (ARBs) have organ-protective effects in heart failure and may be also effective in doxorubicin-induced cardiomyopathy (DOX-CMP); however, the efficacy of ARBs on the prevention of DOX-CMP have not been investigated. We performed a preclinical experiment to evaluate the preventive effect of a novel ARB, fimasartan, in DOX-CMP. All animals underwent echocardiography and were randomly assigned into three groups: treated daily with vehicle (DOX-only group, n=22), 5 mg/kg of fimasartan (Low-fima group, n=22), and 10 mg/kg of fimasartan (High-fima group, n=19). DOX was injected once a week for six weeks. Echocardiography and hemodynamic assessment was performed at the 8th week using a miniaturized conductance catheter. Survival rate of the High-fima group was greater (100%) than that of the Low-fima (75%) and DOX-only groups (50%). Echocardiography showed preserved left ventricular (LV) ejection fraction in the High-fima group, but not in the DOX-only group (P=0.002). LV dimensions increased in the DOX-only group; however, remodeling was attenuated in the Low-fima and High-fima groups. Hemodynamic assessment showed higher dP/dt in the High-fima group compared with the DOX-only group. A novel ARB, fimasartan, may prevent DOX-CMP and improve survival rate in a dose-dependent manner in a rat model of DOX-CMP and could be a treatment option for the prevention of DOX-CMP.
Angiotensin Receptor Antagonists/*therapeutic use ; Animals ; Biphenyl Compounds/*therapeutic use ; Cardiomyopathies/chemically induced/mortality/*prevention & control ; Doxorubicin/*toxicity ; Echocardiography ; Hemodynamics ; Pyrimidines/*therapeutic use ; Rats ; Rats, Sprague-Dawley ; Receptor, Angiotensin, Type 1/chemistry/*metabolism ; Survival Rate ; Tetrazoles/*therapeutic use ; Ventricular Function, Left/physiology

Cancer stem cells (CSCs) are resistant to chemo- and radio-therapy, and can survive to regenerate new tumors. This is an important reason why various anti-cancer therapies often fail to completely control tumors, although they kill and eliminate the bulk of cancer cells. In this study, we determined whether or not adenine nucleotide translocator-2 (ANT2) suppression could also be effective in inducing cell death of breast cancer stem-like cells. A sub-population (SP; CD44+/CD24-) of breast cancer cells has been reported to have stem/progenitor cell properties. We utilized the adeno-ANT2 shRNA virus to inhibit ANT2 expression and then observed the treatment effect in a SP of breast cancer cell line. In this study, MCF7, MDA-MB-231 cells, and breast epithelial cells (MCF10A) mesenchymally-transdifferentiated through E-cadherin knockdown were used. ANT2 expression was high in both stem-like cells and non-stem-like cells of MCF7 and MDA-MB-231 cells, and was induced and up-regulated by mesenchymal transdifferentiation in MCF10A cells (MCF10AEMT). Knockdown of ANT2 by adeno-shRNA virus efficiently induced apoptotic cell death in the stem-like cells of MCF7 and MDA-MB-231 cells, and MCF10AEMT. Stem-like cells of MCF7 and MDA-MB-231, and MCF10AEMT cells exhibited increased drug (doxorubicin) resistance, and expressed a multi-drug resistant related molecule, ABCG2, at a high level. Adeno-ANT2 shRNA virus markedly sensitized the stem-like cells of MCF7 and MDA-MB-231, and the MCF10AEMT cells to doxorubicin, which was accompanied by down-regulation of ABCG2. Our results suggest that ANT2 suppression by adeno-shRNA virus is an effective strategy to induce cell death and increase the chemosensitivity of stem-like cells in breast cancer.
ATP-Binding Cassette Transporters/*genetics/metabolism ; Adenine Nucleotide Translocator 2/antagonists & inhibitors/genetics ; Adenoviridae/*genetics ; Antineoplastic Agents/pharmacology ; Apoptosis/drug effects/genetics ; Breast Neoplasms ; Cadherins/antagonists & inhibitors/genetics ; Cell Line, Tumor ; Cell Survival/drug effects/genetics ; Cell Transdifferentiation/drug effects ; Doxorubicin/pharmacology ; Drug Resistance, Neoplasm/drug effects/*genetics ; Epithelial-Mesenchymal Transition/drug effects ; Female ; Gene Expression Regulation, Neoplastic/drug effects ; Gene Knockdown Techniques ; Humans ; Neoplasm Proteins/*genetics/metabolism ; Neoplastic Stem Cells/drug effects/*metabolism/pathology ; RNA, Small Interfering/*genetics ; Signal Transduction/drug effects

OBJECTIVETo study the effect of LY294002 on the adriamycin- induced epithelial-mesenchymal transition in human breast carcinoma cells.

METHODSHuman breast carcinoma cells MCF-7 was cultured in vitro and then exposed to adriamycin with or without LY294002. The protein expression levels of Akt, phosphorylated-Akt (p-Akt), Snail, and E-cadherin was detected by Western blot analysis. The mRNA expressions of Snail and E-cadherin were determined by RT-PCR.

RESULTSAdriamycin significantly increased the protein expression of Snail and depressed the protein expression of E-cadherin (P<0.05). The pre-treatment with LY294002 significantly reversed the changes of activities and levels of the above proteins (P<0.05).

CONCLUSIONLY294002 could reverse the adriamycin-induced epithelial-mesenchymal transition in human breast carcinoma cells by regulating the expressions of Snail and E-cadherin through suppressing PI3K/Akt signaling pathway.

Breast Neoplasms ; metabolism ; pathology ; Cadherins ; metabolism ; Chromones ; pharmacology ; Doxorubicin ; pharmacology ; Epithelial-Mesenchymal Transition ; drug effects ; Humans ; MCF-7 Cells ; Morpholines ; pharmacology ; Phosphatidylinositol 3-Kinases ; antagonists & inhibitors ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction ; drug effects ; Snail Family Transcription Factors ; Transcription Factors ; metabolism

S1-M1-80 cells, derived from human colon carcinoma S1 cells, are mitoxantrone-selected ABCG2-overexpressing cells and are widely used in in vitro studies of multidrug resistance(MDR). In this study, S1-M1-80 cell xenografts were established to investigate whether the MDR phenotype and cell biological properties were maintained in vivo. Our results showed that the proliferation, cell cycle, and ABCG2 expression level in S1-M1-80 cells were similar to those in cells isolated from S1-M1-80 cell xenografts (named xS1-M1-80 cells). Consistently, xS1-M1-80 cells exhibited high levels of resistance to ABCG2 substrates such as mitoxantrone and topotecan, but remained sensitive to the non-ABCG2 substrate cisplatin. Furthermore, the specific ABCG2 inhibitor Ko143 potently sensitized xS1-M1-80 cells to mitoxantrone and topotecan. These results suggest that S1-M1-80 cell xenografts in nude mice retain their original cytological characteristics at 9 weeks. Thus, this model could serve as a good system for further investigation of ABCG2-mediated MDR.
ATP Binding Cassette Transporter, Sub-Family G, Member 2 ; ATP-Binding Cassette Transporters ; antagonists & inhibitors ; metabolism ; Adenosine ; analogs & derivatives ; pharmacology ; Animals ; Antineoplastic Agents ; pharmacology ; Cell Cycle ; Cell Line, Tumor ; Cell Proliferation ; Cell Survival ; drug effects ; Cisplatin ; pharmacology ; Colonic Neoplasms ; metabolism ; pathology ; Diketopiperazines ; Doxorubicin ; metabolism ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Female ; Heterocyclic Compounds, 4 or More Rings ; Humans ; Inhibitory Concentration 50 ; KB Cells ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Mitoxantrone ; pharmacology ; Neoplasm Proteins ; antagonists & inhibitors ; metabolism ; Neoplasm Transplantation ; Rhodamine 123 ; metabolism ; Topotecan ; pharmacology

This study aims to investigate the preventive role and potential mechanisms of blocking extracellular HMGB1 function on doxorubicin induced cardiac injury. Mice were treated with HMGB1 blocker glycyrrhizin 1 h before and one time every day (intraperitoneal, 10 mg per mouse) after doxorubicin injection, and sacrificed on the day 14 after doxorubicin challenge. Cardiac function was evaluated by echocardiography and hemodynamic measurement. Myocardial inflammation and collagen deposition were analyzed by immunohistochemistry and picrosirius red staining. The interaction of HMGB1 and TLR2 was assessed by co-immunoprecipitation and confocal microscopy. The protein contents of HMGB1, MyD88, p65NF-kappaB and phospho-p65NF-kappaB were measured by Immunoblot. Compared with mice treated with saline, doxorubicin treatment led to an upregulation in HMGB1 expression. Blocking HMGB1 activity with glycyrrhizin protected mice against cardiac dysfunction, inflammatory response, and cardiac fibrosis induced by doxorubicin challenge. Glycyrrhizin inhibited the interaction of HMGB1 and TLR2, and blocked the downstream signaling of TLR2. In conclusion, blocking HMGB1 protected against doxorubicin induced cardiac injury by inhibiting TLR2 signaling pathway.
Animals ; Anti-Inflammatory Agents ; pharmacology ; Collagen ; metabolism ; Doxorubicin ; Drug Interactions ; Fibrosis ; Glycyrrhizic Acid ; pharmacology ; HMGB1 Protein ; antagonists & inhibitors ; metabolism ; Heart Diseases ; chemically induced ; metabolism ; pathology ; Immunoprecipitation ; Interleukin-17 ; metabolism ; Male ; Mice ; Mice, Inbred ICR ; Myocardium ; metabolism ; pathology ; Random Allocation ; Signal Transduction ; drug effects ; Toll-Like Receptor 2 ; metabolism ; Transforming Growth Factor beta1 ; metabolism ; Up-Regulation

OBJECTIVETo investigate whether neuroblastoma cells LA-N-6 express Foxp3 and whether the expression of Foxp3 is sensitive to chemotherapy by cyclophosvnamide (CTX)and pirarubicin (THP).

METHODSExpression of Foxp3 on LA-N-6 cells was examined by flow cytometry analysis. The dose-effects of chemotherapy drugs including CTX and THP on LA-N-6 cells were investigated by MTT assay. The effects of CTX and THP on Foxp3 expression were examined by flow cytometry and real-time PCR assays.

RESULTSFlow cytometry analysis showed that LA-N-6 cells expressed Foxp3 at a high level. At sub-optimal concentration, chemotherapy drugs CTX and THP significantly down-regulated expression of Foxp3 on LA-N-6 cells at protein level (P<0.05). CTX also decreased the expression of Foxp3 at mRNA level (P<0.05). CONCLSUSIONS: Neuroblastoma cells LA-N-6 express Foxp3 at a high level, which can be suppressed by chemotherapy drugs CTX and THP. These data suggest that chemotherapy might suppress the growth and metastasis of tumor cells partially through inhibiting the expression of Foxp3.

Antineoplastic Agents ; pharmacology ; Cell Line, Tumor ; Cyclophosphamide ; pharmacology ; Doxorubicin ; analogs & derivatives ; pharmacology ; Flow Cytometry ; Forkhead Transcription Factors ; analysis ; antagonists & inhibitors ; genetics ; Humans ; Neuroblastoma ; drug therapy ; immunology ; pathology ; Reverse Transcriptase Polymerase Chain Reaction

The massive reorganization of microtubule network involves in transcriptional regulation of several genes by controlling transcriptional factor, nuclear factor-kappa B (NF-kappaB) activity. The exact molecular mechanism by which microtubule rearrangement leads to NF-kappaB activation largely remains to be identified. However microtubule disrupting agents may possibly act in synergy or antagonism against apoptotic cell death in response to conventional chemotherapy targeting DNA damage such as adriamycin or comptothecin in cancer cells. Interestingly pretreatment of microtubule disrupting agents (colchicine, vinblastine and nocodazole) was observed to lead to paradoxical suppression of DNA damage-induced NF-kappaB binding activity, even though these could enhance NF-kappaB signaling in the absence of other stimuli. Moreover this suppressed NF-kappaB binding activity subsequently resulted in synergic apoptotic response, as evident by the combination with Adr and low doses of microtubule disrupting agents was able to potentiate the cytotoxic action through caspase-dependent pathway. Taken together, these results suggested that inhibition of microtubule network chemosensitizes the cancer cells to die by apoptosis through suppressing NF-kappaB DNA binding activity. Therefore, our study provided a possible anti-cancer mechanism of microtubule disrupting agent to overcome resistance against to chemotherapy such as DNA damaging agent.
Animals ; Antibiotics, Antineoplastic/therapeutic use ; *Apoptosis ; Caspases/metabolism ; Cell Line ; Colchicine/pharmacology ; DNA/metabolism ; *DNA Damage ; Doxorubicin/therapeutic use ; Humans ; Mice ; Microtubules/chemistry/*drug effects/metabolism ; NF-kappa B/antagonists & inhibitors/*metabolism ; Neoplasms/drug therapy ; Nocodazole/pharmacology ; Protein Binding ; Signal Transduction ; Tubulin Modulators/*pharmacology ; Vinblastine/pharmacology

BACKGROUND AND OBJECTIVEMultidrug resistance (MDR) is a major obstacle in the chemotherapy of cancer patients. The aim of this study was to establish a mutidrug-resistant cell line SK-Hep1/DDP and explore its molecular mechanism of the MDR.

METHODSSK-Hep1/DDP cell line was induced by pulse treatment using a high concentration of cisplatin (DDP) in vitro. The chemoresistance indexes of cells were evaluated by CCK-8 assays. The protein of MDR1 (ABCB1), MRP1 (ABCC1), MRP2 (ABCC2) and Bax were detected by Western blotting, and the effect of MDR1 inhibitor cyclosporine A (CsA) on expression of MDR1 proteins in SK-Hep1 and SK-Hep1/DDP cell lines. Flow cytometry was performed to determine the distribution of the cell cycle and cell apoptosis ratio.

RESULTSThe SK-Hep1/DDP cells were 13.76 times more resistant to DDP in comparison with SK-Hep1 cells, and SK-Hep1/DDP cells also exhibited cross-resistance to many other chemotherapeutic agents (adramycin and 5-fuorouracil). MDR1, MRP1, and MRP2 protein expressions were significantly higher in the SK-Hep1/DDP than in the SK-Hep1 (P < 0. 01), but Bax was lower in the SK-Hep1/DDP than in the SK-Hep1(P < 0. 01). There was no obvious influence between SK-Hep1 and SK-Hep1/DDP cells in the expression of MDR1 by MDR1 inhibtor CsA (P > 0. 05). The percentages of cells in G(2)/M and S phase were significantly increased in SK-Hep1/DDP in comparison with those in SK-Hep1 [(20.67 +/- 5.69)% vs. (12.14 +/- 3.36)%; (42.20 +/- 2.65)% vs. (27.91 +/- 2.16)%; P < 0. 01]. After the cells were exposed to 10 μg/mL DDP for 24 h, the cell apoptosis rate of SK-Hep1/DDP was decreased in comparison with SK-Hep1, but it was increased in those with pretreatment of MDR1 inhibitor CsA as compared with those without pretreatment.

CONCLUSIONSA reliable multi-drug resistant human hepatoma cell line SK-Hep1/DDP is successfully established. The MDR mechanisms of this cell lines are closely related to the over-expression of MDR1 MRP1 and MRP2, lower expression of Bax and the attenuated cell apoptosis induced by chemotherapeutic agents.

ATP-Binding Cassette, Sub-Family B, Member 1 ; antagonists & inhibitors ; metabolism ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cisplatin ; pharmacology ; Cyclosporine ; pharmacology ; Doxorubicin ; pharmacology ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Fluorouracil ; pharmacology ; Humans ; Liver Neoplasms ; metabolism ; pathology ; Multidrug Resistance-Associated Proteins ; metabolism ; Vincristine ; pharmacology ; bcl-2-Associated X Protein ; metabolism