Heying Chu

MiR-144 inhibits proliferation and induces apoptosis and autophagy in lung cancer cells by targeting TIGAR.

Background: MiRNAs are noncoding RNAs of 20-24 nucleotides that function as post-transcriptional negative regulators of gene expression. MiRNA genes are usually transcribed by RNA polymerase II in the nucleus. Their initial products are pre-miRNAs which have cap sequences and polyA tails. The p53-induced glycolysis and apoptosis regulator (TIGAR) was discovered through microarray analysis of gene expression following activation of p53. However, little is known about the effect of miR-144 on cell proliferation and apoptosis and how it interacts with TIGAR. Methods: We performed real-time PCR, western blotting, CCK8, colony formation, tumor growth, flow cytometry, Caspase3/7 activity, Hoechst 33342 staining, MDC staining of autophagic cells and luciferase reporter assays to detect the influence of miR-144 to lung cancer cells. Results: miR-144 targeted TIGAR, inhibited proliferation, enhanced apoptosis, and increased autophagy in A549 and H460 cells. Conclusions: Our study improves our understanding of the mechanisms underlying lung cancer pathogenesis and may promote the development of novel targeted therapies.

MiR-495 regulates proliferation and migration in NSCLC by targeting MTA3

Our previous studies have showed that metastasis-associated protein 3 (MTA 3) is overexpressed in non-small cell lung cancer (NSCLC) tissue, and increased MTA3 mRNA levels is a risk factor of lymph node metastasis. Using bioinformatics analyses, we found that MTA3 was a potential target of miR-495. However, the pathophysiological role of miR-495 and its relevance to the growth and development of NSCLC have yet to be investigated. The purpose of this study was to elucidate the molecular mechanisms by which miR-495 acts as a tumor suppressor in NSCLC. qRT-PCR data showed significant downregulation of miR-495 in 56 NSCLC tissue samples and 5 lung cancer cell lines, compared with their adjacent normal tissue; furthermore, western blotting analysis revealed MTA3 protein was overexpressed in the tumor samples compared with the matched adjacent normal tissue. MiR-495 was shown to not only inhibit the proliferation of lung cancer cells (A549 and Calu-3) but also to inhibit cell migration in vitro. Using western blotting and luciferase assays, MTA3 was identified as a target of miR-495. These findings suggest the importance of miR-495 targeting of MTA3 in the regulation of lung cancer growth and migration.

Expression analysis of serum microRNAs in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a disease of unknown etiology with considerable morbidity and mortality. Seeking informative diagnostic markers with greater clinical significance is essential for the early diagnosis of IPF. microRNAs (miRNAs or miRs) have emerged as novel serum diagnostic biomarkers for various diseases. In this study, we performed microarray analysis of the miRNA expression profile in the serum of patients with IPF compared to that of control subjects. We then performed a preliminary analysis of biological functions for the most differentially expressed miRNAs. Some of the microarray results were validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The results from this study provide evidence to link the biological role of miRNAs to IPF, and suggest that miRNAs may undertake a variety of functions. Additionally, we found that the altered expression levels of miR-21, miR-155 and miR-101-3p were associated with forced vital capacity (FVC) and radiological features in IPF. Our data may serve as a basis for further investigation, preferably in large prospective studies, before miRNA can be used as a non-invasive screening tool for IPF in routine clinical practice.

Up-regulation of microRNA-138 induce radiosensitization in lung cancer cells

Deregulation of microRNAs (miRNAs) is implicated in tumor progression. We attempt to identify the association between miR-138 and Sentrin/SUMO-specific protease 1 (SENP1) as a radiosensitization-related gene and characterize the biological function by which SENP1 was regulated by miR-138 to influence radiosensitization in lung cancer cells. In this study, we showed that miRNA-138 is reduced in both lung cancer clinical specimens and cell lines and is effective to inhibit SENP1 expression. Moreover, high levels of miR-138 are associated with lower levels of lung cancer cell proliferation and colony formation. Then, we investigated the underlying mechanisms responsible for the increase in the radiosensitivity of lung cancer cells when SENP1 is inhibited by miR-138. We further show that the increased radiosensitivity may be the result of an increased γ-H2AX expression, an increased rate of apoptosis, and changes in the cell cycle. In conclusion, our data demonstrate that the miR-138/SENP1 cascade is relative to radiosensitization in lung cancer cells and is a potential radiotherapy target.

Downregulation of microRNA-182 inhibits cell growth and invasion by targeting programmed cell death 4 in human lung adenocarcinoma cells

Lung cancer is a major cause of cancer death worldwide. Programmed cell death 4 (PDCD4), an important tumor suppressor, influences transcription and translation of multiple genes and modulates different signal transduction pathways. However, the upstream regulation of this gene is largely unknown. In our study, we found that microRNA-182 (miR-182) was upregulated, whereas PDCD4 was downregulated in lung cancer cell lines. We performed methyl thiazolyl tetrazolium and colony formation assays to study the influence of miR-182 on proliferation of the lung cancer cell lines A549 and SPC-A-1. We also carried out Transwell and wound healing assays to investigate the effect of miR-182 on invasion and migration of A549 and SPC-A-1. Finally, using the luciferase reporter assay and restore assay, we demonstrated that PDCD4 is a direct target of miR-182. These results suggest that in lung adenocarcinoma cells, miR-182 plays an oncogenic role as a direct negative regulator of PDCD4.

Silencing BMP-2 expression inhibits A549 and H460 cell proliferation and migration

BackgroundBone morphogenetic protein 2 (BMP-2) is a member of the TGF-β superfamily that is closely correlated with many malignancies, particularly lung cancer. However, the effects of silenced BMP-2 on lung cancer cell proliferation and migration are not clear.MethodsUsing quantitative real-time RT-PCR, BMP-2 mRNA expression was detected in 61 non-small cell lung cancer (NSCLC) samples. Survival curves were generated using follow-up data. Relationships between clinical or pathological characteristics and prognosis were analyzed. Cell viability assays and transwell migration assays were used to evaluate the effects of BMP-2 silencing on cell proliferation and migration of A549 and H460 cells.ResultsBMP-2 mRNA expression was higher in NSCLC tissues compared to matched adjacent normal tissues (P < 0.01). High BMP-2 expression levels were significantly associated with the occurrence of lymph node metastases and tumor stage (P < 0.05). There were significant differences in survival curves between groups with metastatic lymph nodes and non-metastatic lymph nodes, as well as between groups with low BMP-2 expression and groups with high BMP-2 expression. In addition, we observed decreased proliferation and migration rates of the NSCLC-derived cell lines A549 and H460 that were transfected with siBMP-2 (P < 0.05).ConclusionBMP-2 mRNA is overexpressed in NSCLC samples and is a risk factor for survival in patients with NSCLC. BMP-2 silencing can significantly inhibit A549 and H460 cell proliferation and migration.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4263254471298866

Study on expression of lncRNA RGMB-AS1 and repulsive guidance molecule b in non-small cell lung cancer

BackgroundThe relationships between lncRNAs and tumors have currently become one of the focuses on cancer studies. However, there are a few studies about lncRNAs in non-small cell lung cancer (NSCLC) at present.MethodsMicroarray analysis was designed to study the expression patterns of lncRNAs in three pairs of NSCLC tissues. The expression of lncRNA RGMB-AS1 and repulsive guidance molecule b (RGMB) were detected in 72 paired NSCLC tissues and adjacent normal tissues by qRT-PCR assay. The relations of lncRNA RGMB-AS1 and RGMB expression with clinicopathological factors of NSCLC patients were explored. A549 and SPC-A-1 cells were transfected with siRNA of lncRNA RGMB-AS1 and negative control. RGMB expression level was detected by qRT-PCR assay and western blot analysis.ResultsThe results of microarray found that 571 lncRNAs were differentially expressed in NSCLC tissues (Fold change cut-off: 5.0, P < 0.05), including 304 upregulated and 267 downregulated lncRNAs. The results of qRT-PCR showed that lncRNA RGMB-AS1 expression was significantly higher in NSCLC tissues than in adjacent normal tissues (P < 0.05), while RGMB mRNA showed an opposite trend (P < 0.05). Correlation analysis indicated that the expression of lncRNA RGMB-AS1and RGMB mRNA were inversely correlated (R2 = 0.590, P < 0.05). While lncRNA RGMB-AS1 and RGMB expression levels in NSCLC tissues were associated with the occurrence of differentiation status, lymph node metastases and TNM stage (P < 0.05). Transfection with siRNA of lncRNA RGMB-AS1, subsequent results showed that RGMB mRNA and protein expression were upregulated (P < 0.05) in A549 and SPC-A-1 cells compared to the control groups.ConclusionWe identified lncRNA RGMB-AS1 was upregulated and RGMB was downregulated in NSCLC patients. Both were related to differentiation status, lymph node metastases and TNM stage. Studies also indicated that lncRNA RGMB-AS1and RGMB were inversely correlated.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7911587521528276

MALAT1/miR-101-3p/MCL1 axis mediates cisplatin resistance in lung cancer

In this study, we investigated the mechanism by which lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) mediates cisplatin resistance in lung cancer. Lung cancer patients with high MALAT1 levels were associated with cisplatin resistance and low overall survival. Moreover, cisplatin-resistant A549/DDP cells showed higher MALAT1 expression than cisplatin-sensitive lung cancer cells (A549, H460, H1299 and SPC-A1). Dual luciferase reporter and RNA immunoprecipitation assays showed direct binding of miR-101-3p to MALAT1. MALAT1 knockdown in lung cancer cells resulted in miR-101-3p upregulation and increased cisplatin sensitivity. In addition, miR-101-3p decreased myeloid cell leukemia 1 (MCL1) expression by binding to the 3’-untranslated region (3’-UTR) of its mRNA. These results demonstrate that MALAT1/miR-101-3p/MCL1 signaling underlies cisplatin resistance in lung cancer.

Construction and characterization of a eukaryotic expression vector for small interfering RNA targeting the NEDD9 gene

The aim of this study was to construct a eukaryotic expression vector for a small interfering RNA (siRNA) targeting the neural precursor cell expressed, developmentally downregulated 9 (NEDD9) gene, and to investigate the effects of RNA interference (RNAi) on NEDD9 expression in human lung adenocarcinoma A549 cells. We used the siRNA design and analysis software to determine the target oligonucleotides according to the sequence of NEDD9 mRNA available in GenBank. Four siRNA sequences were obtained, and the corresponding cDNAs were synthesized and inserted into the pRNAT-CMV3.2 plasmid to construct the recombinant plasmids. These were transformed into the E. coli strain DH5α. The plasmids, after identification by PCR and DNA sequencing, were transfected into the A549 cell line via the liposome method. NEDD9 mRNA and protein in the cells were determined by fluorescence quantitative RT-PCR (FQ-PCR) and western blotting, respectively. The pRNAT-CMV3.2-transfected plasmid was used as a control. Four recombinant plasmids were identified by PCR and sequence analysis, which contained the correct insertion of the designed sequences in the plasmids. FQ-PCR and western blotting showed substantially decreased mRNA and protein expression of the NEDD9 gene in the transfected cells, compared with the control group. In conclusion, the recombinant plasmids expressing the siRNA targeting the NEDD9 gene were successfully constructed, and the siRNA expression vectors inhibited the expression of NEDD9 in A549 cells.