Tongshan Wang

miR‐181b modulates multidrug resistance by targeting BCL2 in human cancer cell lines

MicroRNAs (miRNAs) are short noncoding RNA molecules, which posttranscriptionally regulate genes expression and play crucial roles in diverse biological processes, such as development, differentiation, apoptosis and proliferation. Here, we investigated the possible role of miRNAs in the development of multidrug resistance (MDR) in human gastric and lung cancer cell lines. We found that miR‐181b was downregulated in both multidrug‐resistant human gastric cancer cell line SGC7901/vincristine (VCR) and multidrug‐resistant human lung cancer cell line A549/cisplatin (CDDP), and the downregulation of miR‐181b in SGC7901/VCR and A549/CDDP cells was concurrent with the upregulation of BCL2 protein, compared with the parental SGC7901 and A549 cell lines, respectively. In vitro drug sensitivity assay demonstrated that overexpression of miR‐181b sensitized SGC7901/VCR and A549/CDDP cells to anticancer drugs, respectively. The luciferase activity of a BCL2 3′‐untranslated region‐based reporter construct in SGC7901/VCR and A549/CDDP cells suggests that a new target site in the 3′UTR of BCL2 of the mature miR‐181s (miR‐181a, miR‐181b, miR‐181c and miR‐181d) was found. Enforced miR‐181b expression reduced BCL2 protein level and sensitized SGC7901/VCR and A549/CDDP cells to VCR‐induced and CDDP‐induced apoptosis, respectively. Taken together, our findings suggest that miR‐181b could play a role in the development of MDR in both gastric and lung cancer cell lines, at least in part, by modulation of apoptosis via targeting BCL2.

miR-497 modulates multidrug resistance of human cancer cell lines by targeting BCL2

MicroRNAs (miRNAs) are short non-coding RNA molecules, which posttranscriptionally regulate genes expression and play crucial roles in diverse biological processes, such as development, differentiation, apoptosis, and proliferation. Here, we investigated the possible role of miRNAs in the development of multidrug resistance (MDR) in human gastric and lung cancer cell lines. We found that miR-497 was downregulated in both multidrug-resistant human gastric cancer cell line SGC7901/vincristine (VCR) and multidrug-resistant human lung cancer cell line A549/cisplatin (CDDP) and the downregulation of miR-497 was concurrent with the upregulation of BCL2 protein, compared with the parental SGC7901 and A549 cell lines, respectively. In vitro drug sensitivity assay demonstrated that overexpression of miR-497 sensitized SGC7901/VCR and A549/CDDP cells to anticancer drugs, respectively. The luciferase activity of BCL2 3′-untranslated region-based reporter constructed in SGC7901/VCR and A549/CDDP cells suggested that BCL2 was the direct target gene of miR-497. Enforced miR-497 expression reduced BCL2 protein level and sensitized SGC7901/VCR and A549/CDDP cells to VCR-induced and CDDP-induced apoptosis, respectively. Taken together, our findings first suggested that has-miR-497 could play a role in both gastric and lung cancer cell lines at least in part by modulation of apoptosis via targeting BCL2.

miR-200bc/429 cluster modulates multidrug resistance of human cancer cell lines by targeting BCL2 and XIAP

PurposeMicroRNAs (miRNAs) are short non-coding RNA molecules, which post-transcriptionally regulate genes expression and play crucial roles in diverse biological processes. Recent studies have shown that dysregulation of miRNAs might modulate the resistance of cancer cells to anti-cancer drugs, yet the modulation mechanism is not fully understood. We aimed to investigate the possible role of miRNAs in the development of multidrug resistance (MDR) in human gastric and lung cancer cell lines.MethodsmiRNA Quantitative real-time PCR was used to detect the different miRNA expression levels between drug resistant and parental cancer cells. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to test the drug-resistant phenotype changes in cancer cells via over or downregulation of miRNAs. Dual-luciferase activity assay was used to verify the target genes of miRNAs. Western blot analysis and apoptosis assay were used to elucidate the mechanism of miRNAs on modulating drug resistance in cancer cells.ResultsmiR-200bc/429 cluster was downregulated, while BCL2 and XIAP were upregulated in both MDR SGC7901/VCR (vincristine) and A549/CDDP (cisplatin) cells, compared with the parental SGC7901 and A549 cells, respectively. Overexpression of miR-200bc/429 cluster sensitized SGC7901/VCR and A549/CDDP cells to anti-cancer drugs, respectively. Both BCL2 and XIAP 3′-UTR reporters constructed in MDR cells suggested that BCL2 and XIAP were the common target genes of the miR-200bc/429 cluster. Enforced miR-200bc/429 cluster expression reduced BCL2 and XIAP protein level and sensitized both MDR cells to VCR-induced and CDDP-induced apoptosis, respectively.ConclusionsOur findings first suggest that miR-200bc/429 cluster could play a role in the development of MDR in both gastric and lung cancer cell lines, at least in part by modulation of apoptosis via targeting BCL2 and XIAP.

Prognostic Value of PLR in Various Cancers: A Meta-Analysis

Background Recently, more and more studies investigated the association of inflammation parameters such as the Platelet Lymphocyte Ratio (PLR) and the prognosis of various cancers. However, the prognostic role of PLR in cancer remains controversial. Methods We conducted a meta-analysis of published studies to evaluate the prognostic value of PLR in various cancers. In order to investigate the association between PLR and overall survival (OS), the hazard ratio (HR) and its 95% confidence interval (CI) were calculated. Results A total of 13964 patients from 26 studies were included in the analysis. The summary results showed that elevated PLR was a negative predictor for OS with HR of 1.60 (95%CI: 1.35–1.90; Pheterogeneity <0.001). Subgroup analysis revealed that increased PLR was a negative prognostic marker in patients with gastric cancer (HR = 1.35, 95%CI: 0.80–2.25, Pheterogeneity = 0.011), colorectal cancer (HR = 1.65, 95%CI: 1.33–2.05, Pheterogeneity = 0.995), hepatocellular carcinoma (HR = 3.07, 95% CI: 2.04–4.62, Pheterogeneity = 0.133), ovarian cancer (HR = 1.57, 95%CI: 1.07–2.31, Pheterogeneity = 0.641) and non-small cell lung cancer (NSCLC) (HR = 1.85, 95% CI: 1.42–2.41, Pheterogeneity = 0.451) except for pancreatic cancer (HR = 1.00, 95%CI: 0.92–1.09, Pheterogeneity = 0.388). Conclusion The meta-analysis demonstrated that PLR could act as a significant biomarker in the prognosis of various cancers.

Effects of treatment with histone deacetylase inhibitors in solid tumors: a review based on 30 clinical trials

It has been found that the epigenetic silence of tumor suppressor genes induced by overexpression of histone deacetylases (HDACs) plays an important role in carcinogenesis. HDAC inhibitors (HDACi) that block the activity of specific HDACs have emerged as the accessory therapeutic agents for multiple human cancers. To better understand the effects of HDACi in cancer treatment, we carried out a review based on 30 published clinical trials to determine whether HDACi will benefit patients with solid tumors. Information of complete response, partial response, stable disease, objective responses and objective response rate was collected to assess clinical outcomes. A lack of therapeutic effects was observed when HDACi was used as a single agent. However, when HDACi treatment was combined with other agents, it appeared to increase the anti-tumor activity. High-quality studies are required to better understand the clinical effects of HDACi.

MiR-135a targets JAK2 and inhibits gastric cancer cell proliferation

The role of tumor suppressors and cell cycle factors in gastric carcinogenesis are well understood; however, the post-transcriptional changes that affect gene expression in gastric cancer are poorly characterized. MiR-135a has been shown to play a role in Hodgkin lymphoma. The aim of this study was to investigate the expression and role of miR-135a in gastric cancer. Quantitative real-time PCR demonstrated that miR-135a expression is downregulated in the majority of human primary gastric cancer tissues (8/11; 73%), compared with pair-matched adjacent non-tumor tissues. Furthermore, compared with the nonmalignant gastric cell line, GES-1, miR-135a expression was substantially downregulated in gastric cancer cell lines of various degrees of differentiation. Target analysis indicated miR-135a directly regulates Janus kinase 2 (JAK2), a cytoplasmic tyrosine kinase involved in cytokine receptor signaling pathways. Overexpression of miR-135a significantly downregulated the expression of JAK2 protein and also reduced gastric cancer cell proliferation and colony formation in vitro. MiR-135a-mediated JAK2 downregulation also reduced p-STAT3 activation and cyclin D1 and Bcl-xL protein expression. This study suggests that miR-135a may function as a tumor suppressor via targeting JAK to repress p-STAT3 activation, reduce cyclin D1 and Bcl-xL expression and inhibit gastric cancer cell proliferation. These results imply that novel treatment approaches targeting miR-135a may potentially benefit patients with gastric cancer.

Diagnostic value of a plasma microRNA signature in gastric cancer: a microRNA expression analysis

The differential expression of microRNAs (miRNAs) in plasma of gastric cancer (GC) patients may serve as a diagnostic biomarker. A total of 33 miRNAs were identified through the initial screening phase (3 GC pools vs. 1 normal control (NC) pool) using quantitative reverse transcription polymerase chain reaction (qRT-PCR) based Exiqon panel (miRCURY-Ready-to-Use-PCR-Human-panel-I + II-V1.M). By qRT-PCR, these miRNAs were further assessed in training (30 GC VS. 30 NCs) and testing stages (71 GC VS. 61 NCs). We discovered a plasma miRNA signature including five up-regulated miRNAs (miR-185, miR-20a, miR-210, miR-25 and miR-92b), and this signature was evaluated to be a potential diagnostic marker of GC. The areas under the receiver operating characteristic curve of the signature were 0.86, 0.74 and 0.87 for the training, testing and the external validation stages (32 GC VS. 18 NCs), respectively. The five miRNAs were consistently dysregulated in GC tissues (n = 30). Moreover, miR-185 was decreased while miR-20a, miR-210 and miR-92b were increased in arterial plasma (n = 38). However, none of the miRNAs in the exosomes showed different expression between 10 GC patients and 10 NCs. In conclusion, we identified a five-miRNA signature in the peripheral plasma which could serve as a non-invasive biomarker in detection of GC.

Paeoniflorin suppress NF-κB activation through modulation of IκBα and enhances 5-fluorouracil-induced apoptosis in human gastric carcinoma cells

OBJECTIVE We sought to determine whether paeoniflorin enhances 5-fluorouracil-induced apoptosis in human gastric carcinoma cells, and, if so, to determine the relationship between this apoptosis and NF-kappaB activation. METHODS Paeoniflorin was diluted to different concentrations and added to gastric carcinoma cells (SGC-7901) at different times. Western blot was used to test the expression of NF-kappaB in nuclear and I kappaB alpha, p-I kappaB alpha, IKK alpha in cytoplasm. Further, the intranuclear expression of NF-kappaB was confirmed by ELISA assay. The impact of paeoniflorin and 5-fluorouracil on cell apoptosis of gastric carcinoma cells was estimated by flow cytometry. RESULTS Paeoniflorin revealed dramatic inhibition of NF-kappaB activity in the nuclei of the cells. The inhibition pattern of NF-kappaB was exhibited in a time- and dose-dependent manner, which was confirmed by Western blot and ELISA. Decreased nuclear translocation of NF-kappaB induced by paeoniflorin was found by preventing I kappaB alpha phosphorylation. Moreover, 5-fluorouracil-induced cell apoptosis was promoted by paeoniflorin in gastric carcinoma cells. CONCLUSIONS Paeoniflorin can inhibit NF-kappaB activity of SGC-7901 cells, and enhance 5-fluorouracil-induced apoptosis of gastric carcinoma cells.

miR-503 regulates the resistance of non-small cell lung cancer cells to cisplatin by targeting Bcl-2

Drug resistance is one of the leading causes of chemotherapy failure in cancer treatment. MicroRNAs (miRNAs or miRs) are short non-coding RNA molecules that post-transcriptionally regulate gene expression and play a critical role in diverse biological processes. In this study, we report that miR-503 regulates the resistance of non-small cell lung cancer cells to cisplatin. The expression of miR-503 was decreased in the cisplatin-resistant non-small cell lung cancer cells, A549/CDDP, compared with the parental A549 cells. The overexpression of miR-503 sensitized the A549/CDDP cells to cisplatin, whereas the inhibition of miR-503 in the A549 cells increased resistance to cisplatin. Mechanistically, miR-503 specifically targeted Bcl-2, an anti-apoptotic protein upregulated in the A549/CDDP cells. The ectopic expression of miR-503 reduced the Bcl-2 protein level and sensitized the A549/CDDP cells to cisplatin-induced apoptosis. Taken together, our results suggest that miR-503 regulates cell apoptosis, at least in part by targeting Bcl-2, and thus modulates the resistance of non-small cell lung cancer cells to cisplatin.

Autophagy inhibition of hsa-miR-19a-3p/19b-3p by targeting TGF-β R II during TGF-β1-induced fibrogenesis in human cardiac fibroblasts

Transforming growth factor-β1 (TGF-β1) plays an important role on fibrogenesis in heart disease. MicroRNAs have exhibited as crucial regulators of cardiac homeostasis and remodeling in various heart diseases. MiR-19a-3p/19b-3p expresses with low levels in the plasma of heart failure patients. The purpose of our study is to determine the role of MiR-19a-3p/19b-3p in regulating autophagy-mediated fibrosis of human cardiac fibroblasts. We elucidate our hypothesis in clinical samples and human cardiac fibroblasts (HCF) to provide valuable basic information. TGF-β1 promotes collagen I α2 and fibronectin synthesis in HCF and that is paralleled by autophagic activation in these cells. Pharmacological inhibition of autophagy by 3-methyladenine decreases the fibrotic response, while autophagy induction of rapamycin increases the response. BECN1 knockdown and Atg5 over-expression either inhibits or enhances the fibrotic effect of TGF-β1 in experimental HCF. Furthermore, miR-19a-3p/19b-3p mimics inhibit epithelial mesenchymal transition (EMT) and extracellular matrix (ECM) prodution and invasion of HCF. Functional studies suggest that miR-19a-3p/19b-3p inhibits autophagy of HCF through targeting TGF-β R II mRNA. Moreover, enhancement of autophagy rescues inhibition effect of miR-19a-3p/19b-3p on Smad 2 and Akt phosphorylation through TGF-β R II signaling. Our study uncovers a novel mechanism that miR-19a-3p/19b-3p inhibits autophagy-mediated fibrogenesis by targeting TGF-β R II.