miR-1908 Overexpression Inhibits Proliferation, Changing Akt Activity and p53 Expression in Hypoxic NSCLC Cells

Regulation of Cancer-Associated miRNAs Expression under Hypoxic Conditions

Solid tumors frequently experience hypoxia or low O2 levels. In these conditions, hypoxia-inducible factor 1 alpha (HIF-1α) is activated and acts as a transcription factor that regulates cancer cell adaptation to O2 and nutrient deprivation. HIF-1α controls gene expression associated with various signaling pathways that promote cancer cell proliferation and survival. MicroRNAs (miRNAs) are 22-nucleotide noncoding RNAs that play a role in various biological processes essential for cancer progression. This review presents an overview of how hypoxia regulates the expression of multiple miRNAs in the progression of cancer cells.

Modulation of AKT Pathway-Targeting miRNAs for Cancer Cell Treatment with Natural Products

Many miRNAs are known to target the AKT serine-threonine kinase (AKT) pathway, which is critical for the regulation of several cell functions in cancer cell development. Many natural products exhibiting anticancer effects have been reported, but their connections to the AKT pathway (AKT and its effectors) and miRNAs have rarely been investigated. This review aimed to demarcate the relationship between miRNAs and the AKT pathway during the regulation of cancer cell functions by natural products. Identifying the connections between miRNAs and the AKT pathway and between miRNAs and natural products made it possible to establish an miRNA/AKT/natural product axis to facilitate a better understanding of their anticancer mechanisms. Moreover, the miRNA database (miRDB) was used to retrieve more AKT pathway-related target candidates for miRNAs. By evaluating the reported facts, the cell functions of these database-generated candidates were connected to natural products. Therefore, this review provides a comprehensive overview of the natural product/miRNA/AKT pathway in the modulation of cancer cell development.

miR-1908: a microRNA with diverse functions in cancers and non-malignant conditions

MicroRNAs (miRNAs) are small-sized transcripts with about 22 nucleotide length. They have been shown to influence almost every aspect of cellular functions through regulation of expression of target genes. miR-1908 is a miRNA with diverse roles in human disorders. This miRNA is encoded by MIR1908 gene on chr11:61,815,161-61,815,240, minus strand. Expression assays have confirmed dysregulation of miR-1908 in cancer-derived cell lines in addition to biological samples obtained from patients affected with cancer. In most assessed cell lines, miR-1908 has an oncogenic role. However, this miRNA has been shown to act as a tumor suppressor in chordoma, lung cancer and ovarian cancer. In addition, several lines of evidence have shown involvement of this miRNA in the pathoetiology of bipolar disorder, myocardial infarction, obesity, renal fibrosis, rheumatoid arthritis and scar formation. In the current review, we elucidate the results of diverse studies which evaluated participation of miR-1908 in these conditions.

miR-1908 Dysregulation in Human Cancers

MiR-1908 is a miRNA located in the intron of the fatty acid desaturase 1 (FADS1) gene. The expression level of miR-1908 is abnormal in many diseases such as cancer. miR-1908 can inhibit the expression of at least 27 target genes by binding to the 3’ untranslated region (3’ UTR) of target genes. miR-1908 is involved in the biological processes of cell proliferation, cell differentiation, cell apoptosis, cancer cell invasion, and metastasis. The expression of miR-1908 is regulated by 11 factors, including lncRNA HOTTIP, adipokines (TNF-α, leptin, and resistin), NF-κB, free fatty acid (FFA), cholesterol, stearoyl-CoA desaturase (SCD1), immune-related transcription factors (STAT1, RB1, and IRF1). The expression of miR-1908 is also affected by the anticancer drug OSW-1, growth hormone (GH), and the anticonvulsant drug sodium valproate. In addition, the aberrant expression of miR-1908 is also related to the prognosis of a variety of cancers, including non-small cell lung cancer (NSCLC), ovarian cancer (OC), breast cancer, cervical cancer, glioma, high-grade serous ovarian carcinoma (HGSOC), osteosarcoma, etc. This article summarizes the abnormal expression pattern of miR-1908 in various diseases and its molecular regulation mechanisms. Our work will provide potential hints and direction for future miR-1908-related research.

Distinct roles of miR-34 family members on suppression of lung squamous cell carcinoma

miR-34, whose mimic was used on phase I clinical trial, has been extensively reported since its dysfunction in various cancers including non-small-cell lung cancer (NSCLC). However, the roles of miR-34 family members in the progression of lung squamous carcinoma (SCC) in patients who have occupational-exposure experience are unclear yet. Here, we comprehensively investigated the expression levels of miR-34 family members in SCC patients and compared the roles of them in SCC in vitro and vivo. The results showed that the average levels of miR-34a and miR-34b/c were decreased in patients. The analysis of miR-34a to miR-34b/c levels in patients graded different stages or metastases or recurrence showed that miR-34b/c was reduced earlier and more significantly than miR-34a. In vitro assays demonstrated that both miR-34a and miR-34b/c inhibits SCC cells proliferation, migration and invasion via Notch1 pathway, while miR-34b/c effects more than miR-34a does. As miR-34a was significantly decreased in cancer recurrence, the further analysis of relationship between miR-34a and stem cell adhesion molecular CD44 showed that miR-34a was significantly correlated with CD44 levels in patients. Knockdown of CD44 significantly blocked miR-34a mediated inhibition of cell migration and invasion. Treating the purified CD44^hi cells with miR-34 overexpression lentivirus inhibited the tumor outgrowth. By contrast, anti-miR-34 facilitated tumor development of CD44^low cells. Our study showed that miR-34 family members are negative regulator for SCC development, even though the inhibition is mediated by multiple and complicated signal pathways, which provides theoretical basis for SCC treatment and a biomarker candidate for SCC prognosis.

A Common Polymorphism in the FADS1 Locus Links miR1908 to Low-Density Lipoprotein Cholesterol Through BMP1

[Figure: see text].

The miR-1908/SRM regulatory axis contributes to extracellular vesicle secretion in prostate cancer

Targeting extracellular vesicle (EV) secretion can have potential clinical implications for cancer therapy, however the precise regulatory mechanisms of EV secretion are not fully understood. Recently, we have shown a novel pathway of EV biogenesis in PCa cell lines, PC3 and PC3M. However, as the characteristics of EVs are divergent even among PCa cell lines, we hypothesized that other pathways or common regulatory pathways of EV biogenesis still exist. Here, we performed quantitative high‐throughput screening to determine the key regulatory genes involved in EV biogenesis in 22Rv1 cells, which secrete a different type of EVs. In total, 1728 miRNAs were screened and miR‐1908 was selected as the potential miRNA regulating EV biogenesis in 22Rv1 cells. Subsequently, we investigated target genes of miR‐1908 using siRNA screening and identified that spermidine synthase (SRM) was the key regulator of EV secretion in 22Rv1 cells. Attenuation of SRM expression significantly inhibited secretion of EVs in 22Rv1 cells, and overexpression of SRM was confirmed in PCa tissues. Furthermore, we found that the number of endosome compartments was increased in cellular cytoplasm after knockdown of the SRM gene. In conclusion, our results showed that miR‐1908‐mediated regulation of SRM can control secretion of EVs in PCa. In addition, these data suggested that the EV secretion pathway was dependent on cellular characteristics.

MiR-1908/EXO1 and MiR-203a/FOS, regulated by scd1, are associated with fracture risk and bone health in postmenopausal diabetic women

Background: Stearoyl–coenzyme A desaturase-1 (SCD1) can inhibit the development of diabetic bone disease by promoting osteogenesis. In this study, we examined whether this regulation by SCD1 is achieved by regulating the expression of related miRNAs.

Methods: SCD1 expression levels were observed in human bone-marrow mesenchymal stem cells (BM-MSCs) of patients with type 2 diabetes mellitus (T2DM), and the effect of SCD1 on osteogenesis was observed in human adipose-derived MSCs transfected with the SCD1 lentiviral system. We designed a bioinformatics prediction model to select important differentially expressed miRNAs, and established protein–protein interaction and miRNA–mRNA networks. miRNAs and mRNAs were extracted and their differential expression was detected. The SCD1–miRNA–mRNA network was validated.

Findings: SCD1 expression in bone marrow was downregulated in patients with T2DM and low-energy fracture, and SCD1 expression promotes BM-MSC osteogenic differentiation. The predictors in the nomogram were seven microRNAs, including hsa-miR-1908 and hsa-miR-203a. SCD1 inhibited the expression of CDKN1A and FOS, but promoted the expression of EXO1 and PLS1. miR-1908 was a regulator of EXO1 expression, and miR-203a was a regulator of FOS expression.

Interpretation: The regulation of BM-MSCs by SCD1 is a necessary condition for osteogenesis through the miR-203a/FOS and miR-1908/EXO1 regulatory pathways.

MicroRNA-584 inhibits cell proliferation and invasion in non-small cell lung cancer by directly targeting MTDH

Lung cancer is the third most frequent human malignant tumour and the leading cause of cancer-associated mortality worldwide. Emerging lines of evidence have demonstrated that microRNAs (miRNAs) are upregulated or downregulated in non-small cell lung cancer (NSCLC), and this phenomenon is involved in the regulation of various processes during tumorigenesis and progression, including tumour groWTh, apoptosis, cell invasion, and tumour metastasis. Therefore, understanding the molecular mechanism that associates abnormally expressed miRNAs with NSCLC formation and development may lead to the identification of novel diagnostic, and therapeutic targets for patients with NSCLC. miRNA-584 (miR-584) functions as a tumour suppressor in several types of cancer. However, the expression pattern, detailed biological function and underlying molecular mechanism of miR-584 in NSCLC remain unclear. Therefore, the present study detected the expression of miR-584 in NSCLC, investigated its role in NSCLC cells and determined its underlying molecular mechanism. In the current study, it was demonstrated that miR-584 was downregulated in NSCLC tissues and cell lines. Low miR-584 expression was correlated with tumour size, tumour node metastasis stage and distant metastasis. Overexpression of miR-584 inhibited cell proliferation and invasion in NSCLC. Additionally, metadherin was identified as a direct target gene of miR-584 in NSCLC as confirmed by a series of experiments. Moreover, upregulation of miR-584 was involved in the regulation of the phosphatase and tensin homolog/Akt serine/threonine kinase signalling pathway in NSCLC. Thus, miR-584 may serve as a tumor-suppressor, and the results of the present study provide a reference for future research into the potential mechanisms underlying NSCLC progression.

MicroRNAs as regulators of cisplatin-resistance in non-small cell lung carcinomas

With more than 80% of all diagnosed lung cancer cases, non-small cell lung cancer (NSCLC) remains the leading cause of cancer death worldwide. Exact diagnosis is mostly very late and advanced-stage NSCLCs are inoperable at admission. Tailored therapies with tyrosine kinase inhibitors are only available for a minority of patients. Thus, chemotherapy is often the treatment of choice. As first-line chemotherapy for NSCLCs, platinum-based substances (e.g. cisplatin, CDDP) are mainly used. Unfortunately, the positive effects of CDDP are frequently diminished due to development of drug resistance and negative influence of microenvironmental factors like hypoxia. MicroRNAs (miRNAs) are small, non-coding molecules involved in the regulation of gene expression and modification of biological processes like cell proliferation, apoptosis and cell response to chemotherapeutics. Expression of miRNAs is often deregulated in lung cancer compared to corresponding non-malignant tissue. In this review we summarize the present knowledge about the effects of miRNAs on CDDP-resistance in NSCLCs. Further, we focus on miRNAs deregulated by hypoxia, which is an important factor in the development of CDDP-resistance in NSCLCs. This review will contribute to the general understanding of miRNA-regulated biological processes in NSCLC, with special focus on the role of miRNA in CDDP-resistance.

Biomarkers identified for prostate cancer patients through genome-scale screening

Prostate cancer is a threat to men and usually occurs in aged males. Though prostate specific antigen level and Gleason score are utilized for evaluation of the prostate cancer in clinic, the biomarkers for this malignancy have not been widely recognized. Furthermore, the outcome varies across individuals receiving comparable treatment regimens and the underlying mechanism is still unclear. We supposed that genetic feature may be responsible for, at least in part, this process and conducted a two-cohort study to compare the genetic difference in tumorous and normal tissues of prostate cancer patients. The Gene Expression Omnibus dataset were used and a total of 41 genes were found significantly differently expressed in tumor tissues as compared with normal prostate tissues. Four genes (SPOCK3, SPON1, PTN and TGFB3) were selected for further evaluation after Gene Ontology analysis, Kyoto Encyclopedia of Genes and Genomes pathway analysis and clinical association analysis. MIR1908 was also found decreased expression level in prostate cancer whose target genes were found expressing in both prostate tumor and normal tissues. These results indicated that these potential biomarkers deserve attention in prostate cancer patients and the underlying mechanism should be further investigated.

The long non-coding RNA MIAT regulates zinc finger E-box binding homeobox 1 expression by sponging miR-150 and promoteing cell invasion in non-small-cell lung cancer

The myocardial infarction associated transcript (MIAT), a long non-coding RNA (lncRNA), was originally identified as a candidate gene for myocardial infarction, and was recently shown to participate in the progression of cancer and the process of metastasis. However, the biological role of MIAT and the underlying mechanisms that mediate its role in non-small-cell lung cancer (NSCLC) remain unclear. Here, we have shown that the expression of MIAT in NSCLC tissues was upregulated. Knockdown of MIAT substantially inhibited the invasive ability of NSCLC cells. Moreover, the knockdown of MIAT significantly downregulated the expression of the zinc finger E-box binding homeobox 1 (ZEB1), that was upregulated in NSCLC and that promoted cell invasion. Rather than by direct interactions, we found that MIAT indirectly regulated ZEB1 expression through sponging and suppressing microRNA (miR)-150, which represses ZEB1 and interacts with MIAT in a sequence-specific manner. Thus, MIAT may inhibit ZEB1 expression and promote cell invasion of NSCLC cells via the miR-150/ZEB1 pathway. Taken together, our findings suggested that MIAT plays an oncogenic role in NSCLC through the ZEB1 signaling pathway by sponging miR-150, and MIAT may therefore serve as a valuable prognostic biomarker and therapeutic target for NSCLC.

miR-103 Functions as a Tumor Suppressor by Directly Targeting Programmed Cell Death 10 in NSCLC

Non-small cell lung cancer (NSCLC) accounts for about 85% of all lung cancer cases. Absence of miR-103 has recently been identified to be associated with metastatic capacity of primary lung tumors. However, the exact role of miR-103 in NSCLC and the molecular mechanism are unclear. In the present study, we showed that miR-103 expression was reduced in NSCLC tissues and cells. miR-103 expression was negatively correlated with tumor size and stage. The overall survival was longer in patients with higher miR-103 level than in those with lower miR-103 expression. miR-103 inhibited cell proliferation in A549 cells, decreased tumor weight and volume, and prolonged survival of tumor-implanted nude mice. miR-103 increased apoptotic cell death in A549 cells. Furthermore, miR-103 decreased the invasion and migration abilities in A549 cells, as evidenced by Transwell and wound healing results. Downregulation of miR-103 significantly reduced the level of programmed cell death 10 (PDCD10). We found a significant decrease in the relative luciferase activity of the reporter gene in A549 cells cotransfected with the miR-103 mimic and pGL3-PDCD10 WT 3′-UTR, but not pGL3-PDCD10 mut 3′-UTR. We showed that overexpression of PDCD10 significantly inhibited miR-103-induced inhibition of cell proliferation, increased apoptosis, and decreased invasion and migration in A549 cells. Moreover, we found that PDCD10 expression was increased in NSCLC tissues and cells. PDCD10 expression was positively correlated with tumor size and stage. Overexpression of PDCD10 increased cell proliferation and inhibited apoptosis in A549 cells. The data demonstrated that dysregulation of the miR-103/PDCD10 signal may be a novel therapeutic target for the treatment of NSCLC.

MiR-130 exerts tumor suppressive function on the tumorigenesis of human non-small cell lung cancer by targeting PTEN

MicroRNAs (miRNAs) have been involved in some human malignancies and correlated with tumor progression. The dysregulation of miR-130 is found in various cancers and correlated with tumor proliferation and apoptosis. However, its expression and function in non-small cell lung cancer (NSCLC) have not been investigated yet. In this study, we demonstrated that miR-130 is significantly down-regulated in NSCLC tissue samples and cell lines. Low miR-130 expression was closely associated with lymph node metastasis, late stages of disease progression and diminished survival in NSCLC patients. The up-regulation of miR-130 could significantly inhibit NSCLC cell growth and enhance cell apoptosis both in vitro and in vivo. Whereas inhibition of miR-130 exerted opposite effects. Furthermore, dual-luciferase reporter assay confirmed that PTEN was regulated by miR-130 directly, and the knockdown of PTEN markedly abrogated the anti-growth effect of miR-130. Additionally, miR-130 was found positively correlated with PTEN in NSCLC specimens. In conclusion, our results suggested that the expression of miR-130 is significantly associated with the growth and apoptosis of NSCLS cells by targeting PTEN, whilst miR-130 may be a potential therapeutic target for NSCLC treatment.