The aim of this study was to investigate the effects of dexmedetomidine (Dex) on hepatic ischemia/reperfusion injury (HIRI) and the underlying mechanism. The in vitro HIRI was induced by culturing HL-7702 cells, a human hepatocyte cell line, under 24 h of hypoxia and 12 h of reoxygenation. Quantitative real time PCR (qRT-PCR) and Western blot were performed to detect the expression levels of long non-coding RNA MALAT1, microRNA-126-5p (miR-126-5p) and high mobility group box-1 (HMGB1). Bioinformatics prediction and double luciferase assay were used to verify the targeting relationship between miR-126-5p and MALAT1, HMGB1. Reactive oxygen species (ROS), malondialdehyde (MDA) and ATP levels in culture medium were detected by corresponding kits. The results showed that Dex significantly reduced the levels of ROS and MDA, but increased the level of ATP in HL-7702 cells with HIRI. HIRI up-regulated the expression levels of MALAT1 and HMGB1, and down-regulated the level of miR-126-5p. Dex reversed these effects of HIRI. Furthermore, Dex inhibited HIRI-induced cellular apoptosis, whereas MALAT1 reversed the effect of Dex. This inhibitory effect of Dex could be restored by up-regulation of miR-126-5p. The results suggest that Dex protects hepatocytes from HIRI via regulating MALAT1/miR-126-5p/HMGB1 axis.
Dexmedetomidine/pharmacology* ; HMGB1 Protein/genetics* ; Humans ; MicroRNAs/genetics* ; RNA, Long Noncoding/genetics* ; Reperfusion Injury/genetics*

OBJECTIVETo analyze the difference in microRNAs expression between MCF-7 and MCF-7/ADR cells and explore the association between microRNA and drug resistance of breast cancer.

METHODSThe drug resistance of MCF-7/ADR cells was evaluated using MTT assay and flow cytometry. Microarray technique and RT-PCR were used to analyze the differential expressions of the microRNA between MCF-7 and MCF-7/ADR cells.

RESULTSThe drug resistance index of MCF-7/ADR cells relative to the parental MCF-7 cells was 33.2. The percentages of the side population in MCF-7/ADR and MCF-7 cells were (9.50-/+0.9)% and (0.85-/+0.2)%, respectively. Microarray analysis of MCF-7 to MCF-7/ADR cells identified 36 differentially expressed genes, including 16 up-regulated and 20 down-regulated genes in MCF-7/ADR cells. RT-PCR identified 14 microRNAs that were differentially expressed between MCF-7 and MCF-7/ADR cells, including 7 up-regulated and 7 down-regulated ones in MCF-7/ADR cells. Of these differentially expressed microRNAs, mir-221, mir222, mir-130a, and mir-155 showed significantly increased expression, and mir200a, mir-200b, mir-200c, and mir-421 showed significantly lowered expression in MCF-7/ADR cells as indicated by the results of microarray analysis and RT-PCR.

CONCLUSIONMCF-7/ADR cells show a different microRNA expression profile from its parental MCF-7 cells, suggesting the involvement of microRNAs in tumor cell drug resistance. This finding provides a experimental basis for further study of mechanism underlying the drug resistance of breast cancer.

Breast Neoplasms ; genetics ; Doxorubicin ; pharmacology ; Drug Resistance, Neoplasm ; genetics ; Female ; Humans ; MicroRNAs ; genetics ; Tumor Cells, Cultured

OBJECTIVE: To investigate the therapeutic effect of gentisic acid (GA) on rheumatoid arthritis (RA) based on the miR-19b-3p/RAF1 axis. METHODS: The cell counting kit-8 method was used to detect the growth inhibitory effect of different concentrations of GA on MH7A cells, and the drug concentration of GA was determined in the experiment. The quantificational real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of miR-19b-3p and RAF1. RAF1, extracellular regulated protein kinases1/2 (ERK1/2) and phospho-ERK1/2 (p-ERK1/2) were examined by Western blotting. Three methods (dual-luciferase assay, qRT-PCR and Western blot analysis) were used to verify miR-19b-3p targeting RAF1. Flow cytometry was performed to detect MH7A cell apoptosis. Transwell and wound healing assays were used to determine the invasion and migration capacities of MH7A cells. RESULTS: The growth of MH7A cells was gradually inhibited with increasing GA concentration. When the GA concentration exceeded 80 mmol/L, GA was significantly cytotoxic to MH7A cells, so the half maximal inhibitory concentration of GA for MH7A cells was calculated as 67.019 mmol/L. GA upregulated miR-19b-3p expression, downregulated RAF1 expression, inhibited ERK1/2 phosphorylation, induced MH7A cell apoptosis and suppressed MH7A cell invasion and migration (P<0.05 or P<0.01). RAF1 was identified as the target of miR-19b-3p and reversed inhibitory effects on miR-19b-3p expression (P<0.05 or P<0.01). The miR-19b-3p inhibitor upregulated RAF1 expression and ERK1/2 phosphorylation, suppressed MH7A cell apoptosis and induced MH7A cell invasion and migration (P<0.01). CONCLUSION GA regulated miR-19b-3p/RAF1 axis to mediate ERK pathway and inhibit the development of RA.
Humans ; Cell Proliferation ; MicroRNAs/metabolism* ; Arthritis, Rheumatoid/genetics* ; Gentisates/pharmacology* ; Cell Movement/genetics*

This study investigated the effect of etoposide, an anticancer chemotherapy drug, on B7-H1 expression in retinoblastoma (Rb) cells and the role of miR-513a-5p in the process. Rb cells were divided into control and etoposide groups. In the etoposide group, cells were treated with etoposide at different concentrations (2.5, 5, 10, 20 and 40 μg/mL) for 24 h. Those given no treatment of etopside served as controls. Reverse transcription polymerase chain reaction (RT-PCR), fluorescence quantitative PCR and flow cytometry were performed to measure the mRNA and protein expression of B7-H1 in Rb cells. The mRNA expression of miR-513a-5p in Rb cells before and after etoposide treatment was also detected by fluorescence quantitative PCR. The miR-513a-5p mimics and the miR-513a-5p inhibitor were transfected into Rb cells separately, and fluorescence quantitative PCR and flow cytometry were used to detect the effect of the miR-513a-5p mimics or inhibitor on B7-H1 expression. TargetScan5.2 was employed to predict the miR-513a-5p binding sites in the 3'-untranslated region of B7-H1 mRNA. Luciferase reporter plasmids carrying this site were prepared and transfected into Rb cells and luciferase activity analyzed. The results showed that etoposide stimulated the mRNA and protein expression of B7-H1 in Rb cells, which reached a maximal level after treatment with 5 μg/mL etoposide (P<0.05). However, miR-513a-5p expression was decreased in Rb cells after etoposide treatment. When the miR-513a-5p inhibitor was added, B7-H1 expression was increased with the concentration of the miR-513a-5p inhibitor (P<0.05). Moreover, B7-H1 expression was decreased gradually with the concentration of the miR-513a-5p mimics increased (P<0.01). Additionally, the miR-513a-5p mimics were found to inhibit the luciferase activity. It was concluded that etoposide can promote B7-H1 expression in Rb cells, which may be associated with chemoresistance. The promoting effect of etoposide on B7-H1 expression can be reversed by miR-513a-5p mimics. MiR-513a-5p inhibits the mRNA and protein expression of B7-H1 via binding to the 3'-UTR of B7-H1 mRNA.
B7-H1 Antigen ; genetics ; Cell Line, Tumor ; Etoposide ; pharmacology ; Gene Expression ; drug effects ; genetics ; Humans ; MicroRNAs ; genetics ; Retinoblastoma ; genetics

OBJECTIVE: To detect the differential expressions of miR-451, ABCB1 and ABCC2 in drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, and explore the regulatory relationship between miR-451 and the expressions of ABCB1 and ABCC2 , and the mechanism of miR-451 involved in drug resistance in leukemia. METHODS: CCK-8 assay was used to detect the drug resistance of K562/A02 and K562 cells. Quantitative Real-time PCR (qRT-PCR) was used to verify the differential expressions of miR-451 in K562 and K562/A02 cells. MiR-451 mimic and negative control (miR-NC), miR-451 inhibitor and negative control (miR-inNC) were transfected into K562 and K562/A02 cells respectively, then qRT-PCR and Western blot were used to detect the expression levels of mRNA and protein of ABCB1 and ABCC2 in K562 and K562/A02 cells and the transfected groups. RESULTS: The drug resistance of K562/A02 cells to adriamycin was 177 times higher than that of its parent cell line K562. Compared with K562 cells, the expression of miR-451 in K562/A02 cells was significantly higher (P <0.001), and the mRNA and protein expression levels of ABCB1 and ABCC2 in K562/A02 cells were significantly higher than those in K562 cells (P <0.001). After transfected with miR-451 inhibitor, the expression of miR-451 was significantly down-regulated in K562/A02 cells (P <0.001), the sensitivity to chemotherapy drugs was significantly enhanced (P <0.05), and the mRNA and protein expressions of ABCB1 and ABCC2 were significantly decreased (P <0.01). After transfected with miR-451 mimic, the expression of miR-451 was significantly upregulated in K562 cells (P <0.001), and the mRNA and protein expressions of ABCB1 and ABCC2 were significantly increased (P <0.01). CONCLUSION There are significant differences in the expressions of miR-451, ABCB1 and ABCC2 between the drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, which suggests that miR-451 may affect the drug resistance of leukemia cells by regulating the expression of ABCB1 and ABCC2.
Humans ; K562 Cells ; Drug Resistance, Neoplasm/genetics* ; Drug Resistance, Multiple/genetics* ; Doxorubicin/pharmacology* ; MicroRNAs/genetics* ; Leukemia/genetics* ; RNA, Messenger

BACKGROUND AND OBJECTIVECurcumin, a natural compound, is derived from the rthizom of Curcuma longa. In vitro and in vivo preclinical studies have shown its anti-inflammatory, antioxidant, anticancer activities and so on. miR-186*, which was found by microarray technology, was highly expressed in lung carcinoma cells A549/DDP. The aim of this study is to illustrate whether Curcumin could promote the apoptosis of A549/DDP cells through regulating the expression of miR-186*.

METHODSAn oligonucleotide microarray chip was used to profile microRNA (miRNA) expressions in A549/DDP cells treated with and without Curcumin. The significantly differentially expressed miRNA, which was selected from microarray chip, validated by quantitative real-time PCR. Ultimately, the remarkably expressed miRNA modulated the apoptosis assaying by flow cytometry expriments and the survival rate was measured by MTT method.

RESULTSThe microarray chip results demonstrated: Curcumin altered the expression level of miRNAs compared with untreated control in A549/DDP cell line, miR-186* was significantly down-regulated after Curcumin treatment, which confirmed by quantitative real-time PCR. Down-regulation of miR-186* expression by curcumin elevated the apoptosis, and the survival rate of A549/DDP cells decreased; but up-regulation of miR-186* expression by transfection its mimics restrained the apoptosis, the survival rate of A549/DDP cells increased, which were assayed by flow cytometry expriments and MTT method.

CONCLUSIONModulation of miRNAs expression may be an important mechanism underlying the biological roles of Curcumin.

Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; genetics ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Curcumin ; pharmacology ; Drug Resistance, Neoplasm ; genetics ; Humans ; Lung Neoplasms ; drug therapy ; genetics ; MicroRNAs ; genetics

OBJECTIVE: To investigate the effect of resveratrol (RSV) on the proliferation of multiple myeloma (MM) cells and its molecular mechanism. METHODS: MM cells (MM1.S, RPMI-8226 and U266) were treated with different concentrations of RSV for 24-72 h. The effect of RSV on the proliferation of MM cells was detected by CCK-8 (cell counting kit-8) assay. RPMI-8226 cells were divided into RSV, miR-21 mimic, RSV+miR-21 mimic, miR-21 inhibitor and RSV+miR-21 inhibitor groups, and transfected with corresponding plasmids. The cell cycle distribution of each group was detected by flow cytometry with propidium iodide (PI) single staining. The cell apoptosis of each group was detected by AnnexinV-FITC/PE-PI double staining. The expression of miR-21 in MM cells treated with RSV and the expression of KLF5 mRNA in each group were detected by qRT-PCR. The expression of KLF5 protein in each group was detected by Western blot. RESULTS: RSV inhibited the proliferation and induced apoptosis of MM cells in a time- and dose-dependent manner. After the MM cells were treated with RSV, the number of cells in sub-G₁ phase was increased, and that in G₂/M phase was decreased. Moreover, RSV significantly downregulated the expression of miR-21 in MM cells, and the inhibitory effect of miR-21 mimic on KLF5 expression in MM cells was counteracted by RSV. CONCLUSION RSV may inhibit the proliferation and induce apoptosis of MM cells by inhibiting miR-21 and up-regulating KLF5 expression.
Humans ; Resveratrol/pharmacology* ; Multiple Myeloma/metabolism* ; Cell Proliferation ; Cell Line, Tumor ; Apoptosis ; MicroRNAs/genetics*

OBJECTIVETo study the expression profile of microRNAs in acute promyelocytic leukemia (APL) cells during differentiation.

METHODSDifferentiation of APL cell line NB4 cells was induced by all-trans retinoic acid (ATRA) and arsenic trioxide (As2O3). Morphological and immunological assay was performed by Wright-Giemsa staining and flow-cytometric analysis of CD11b surface expression. During in vitro NB4 differentiation induced by ATRA and As2O3, microRNA expression profiles (miR-15b, miR-16, miR-34a, miR-107, miR-124a, miR-146, miR-155, miR-181a, miR-223, miR-342, let7c) were detected by real time RT-PCR, and the relative expression level of microRNAs were quantitatively analyzed by using 2(-ΔΔCt), and compared with that of control group. Meanwhile, the microRNA expression profiles were also detected in 15 newly diagnosed APL patients and 15 complete remission (CR) APL cases by real time RT-PCR, and the relative expression level of microRNA was quantitated by using 2(-ΔCt), and compared with that of control group (newly diagnosed APL as control group). These data were expressed as x(-) ± s, and differences between groups were examined using t test. P < 0.05 was considered statistically significant.

RESULTSThe expression levels of miR-15b, miR-16, miR-107, miR-223 and miR-342 in NB4 differentiation group were obviously up-regulated (3.40, 4.22, 5.41, 20.03 and 5.29 folds higher in ATRA treated NB4 cells than that of control group respectively, and 3.62, 2.49, 2.58, 4.27 and 1.94 folds higher in AS2O3 treated NB4 cells than that of control group respectively), except for miR-15b, the expression levels of miR-16, miR-107, miR-223 and miR-342 in ATRA treated group was significantly higher than that in As2O3 treated group. The relative expression levels of miR-15b, miR-16, miR-107, miR-181a, miR-223 and miR-342 were 0.4137, 0.6367, 0.1260, 0.0522, 0.6611, 0.0280 in APL CR group, and 0.0751, 0.2022, 0.0425, 0.3064, 0.1733, 0.0090 in newly diagnosed APL group, respectively. The expression level of miR-15b, miR-16, miR-107, miR-223 and miR-342 in APL CR group were significantly upregulated compared with that of newly diagnosed APL groups (P < 0.05), while the expression level of miR-181a was significantly downregulated (P < 0.05).

CONCLUSIONSpecific expression of microRNA profiles is a key contributing factor in the differentiation of APL.

Arsenicals ; pharmacology ; Cell Differentiation ; drug effects ; Humans ; Leukemia, Promyelocytic, Acute ; genetics ; metabolism ; MicroRNAs ; genetics ; metabolism ; Oxides ; pharmacology ; RNA, Messenger ; genetics ; Tretinoin ; pharmacology ; Tumor Cells, Cultured

OBJECTIVETo investigate the influence of miR-122 on IFN-α treatment for HCV infection.

METHODSHuh7.5.1 cells infected with HCV were treated with miR-122 mimics (20 nmol/L, 100 nmol/L, 400 nmol/L) and/or IFN-α (1000 IU/ml). The relative expression of HCV RNA was detected by real-time polymerase chain reaction (PCR). Huh7.5.1 cells were treated with different amounts of HCV (107 copies, 106 copies and 105 copies) and/or IFN-α (1000 IU/ml).

RESULTSIFN-α suppressed the replication of HCV in a time-dependent manner, resulting in a ≊ 83% reduction of HCV at 48 h. MiR-122 mimics facilitated replication of HCV RNA in a dose-dependent manner (P<0.05). The antiviral effect of IFN-α was inverted to levels of miR-122 mimics (20 nmol/L, 100 nmol/L, 400 nmol/L), (73.3% ± 3.5% compared with 84% ± 4.5%, P>0.05; 64.67% ± 5.5% compared with 84% ± 4.5%, P>0.05; 56.33% ± 5.1% compared with 84% ± 4.5%, P<0.05). The antiviral effect of IFN-α was inverted to HCV load (105 copies group compared with 107 copies group, P<0.05).

CONCLUSIONMiR-122 facilitates replication of HCV RNA in the cell culture system; and the expression of miR-122 may partly counteract the anti-HCV effect of IFN-α.

Antiviral Agents ; pharmacology ; Cell Line, Tumor ; Hepacivirus ; drug effects ; genetics ; physiology ; Humans ; Interferon-alpha ; pharmacology ; MicroRNAs ; genetics ; RNA, Viral ; genetics ; Transfection ; Virus Replication ; drug effects ; genetics

Resistance to chemotherapy is a major obstacle for the effective treatment of advanced ovarian cancer. The mechanism of chemoresistance is still poorly understood. Recently, more and more evidence showed microRNAs (miRNAs) modulated many key molecules and pathways involved in chemotherapy. microRNA-106a (miR-106a) has been implicated in many cancers, but its role in ovarian cancer and drug resistance still remains unexplored. This study was to investigate whether miR-106a mediated resistance of the ovarian cancer cell line A2780 to the chemotherapeutic agent cisplatin (DDP). The different levels of miR-106a in A2780 cells and their resistant variant A2780/DDP cells were identified by using real-time PCR. MTT assay and flow cytometry were used to analyze the effect of miR-106a on cisplatin resistance of these paired cells. Real-time PCR, Western blotting and luciferase reporter assay were applied to explore whether Mcl-1 was a target of miR-106a. As compared to A2780 cells, the expression of miR-106a was down-regulated in the cisplatin resistant cell line A2780/DDP. Moreover, knockdown of miR-106a dramatically decreased antiproliferative effects and apoptosis induced by cisplatin in A2780 cells, while overexpression of miR-106a significantly increased antiproliferative effects and apoptosis induced by cisplatin in A2780/DDP cells. Furthermore, miR-106a inhibited cell survival and cisplatin resistance through downregulating the expression of Mcl-1. Mcl-1 was a direct target of miR-106a. These results suggest that miR-106a may provide a novel mechanism for understanding cisplatin resistance in ovarian cancer by modulating Mcl-1.
Antineoplastic Agents ; pharmacology ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Drug Resistance, Neoplasm ; genetics ; Female ; Humans ; MicroRNAs ; genetics ; Myeloid Cell Leukemia Sequence 1 Protein ; genetics ; Ovarian Neoplasms ; drug therapy ; genetics