Decreased miR-30b-5p expression by DNMT1 methylation regulation involved in gastric cancer metastasis. Mol Biol Rep. 2014;41:5693-5700. [PMID: 24913034 DOI: 10.1007/s11033-014-3439-4]

In Silico Identification of Dysregulated miRNAs Targeting KRAS Gene in Pancreatic Cancer

Pancreatic cancer (PC) is highly lethal, with KRAS mutations in up to 95% of cases. miRNAs inversely correlate with KRAS expression, indicating potential as biomarkers. This study identified miRNAs targeting KRAS and their impact on PC characteristics using in silico methods. dbDEMC identified dysregulated miRNAs in PC; TargetScan, miRDB, and PolymiRTS 3.0 identified miRNAs specific for the KRAS gene; and OncomiR evaluated the association of miRNAs with clinical characteristics and survival in PC. The correlation between miRNAs and KRAS was analysed using ENCORI/starBase. A total of 210 deregulated miRNAs were identified in PC (116 overexpressed and 94 underexpressed). In total, 16 of them were involved in the regulation of KRAS expression and 9 of these (hsa-miR-222-3p, hsa-miR-30a-5p, hsa-miR-30b-5p, hsa-miR-30e-5p, hsa-miR-377-3p, hsa-miR-495-3p, hsa-miR-654-3p, hsa-miR-877-5p and hsa-miR-885-5p) were associated with the clinical characteristics of the PC. Specifically, the overexpression of hsa-miR-30a-5p was associated with PC mortality, and hsa-miR-30b-5p, hsa-miR-377-3p, hsa-miR-495-3p, and hsa-miR-885-5p were associated with survival. Correlation analysis revealed that the expression of 10 miRNAs is correlated with KRAS expression. The dysregulated miRNAs identified in PC may regulate KRAS and some are associated with clinically relevant features, highlighting their potential as biomarkers and therapeutic targets in PC treatment. However, experimental validation is required for confirmation.

Lactate induces aberration in the miR-30a-DBF4 axis to promote the development of gastric cancer and weakens the sensitivity to 5-Fu

Background

Gastric cancer (GC) is one of the most common malignancies, molecular mechanism of which is still not clear. Aberrant expression of tumor-associated genes is the major cause of tumorigenesis. DBF4 is an important factor in cancers, although there is yet no report on its function and molecular mechanism in GC.

Methods

The expression of DBF4 in tumor tissues or cells of GC was detected by qRT-PCR and western blotting. Gastric cancer cell line MGC-803 and AGS were transfected with DBF4 siRNA or overexpression vector to detect the function of DBF4 in proliferation, migration and the sensitivity to 5-Fu with CCK-8 assay, colony formation assay, transwell assay, and wound healing assay. miR-30a was found to be the regulator of DBF4 by online bioinformatics software and confirmed with qRT-PCR, western blot and dual-luciferase reporter assays.

Results

In our study, increased expression of DBF4 in GC tissues was first identified through The Cancer Genome Atlas (TCGA) and later confirmed using specimens from GC patients. Furthermore, functional experiments were applied to demonstrate that DBF4 promotes cell proliferation and migration in GC cell lines, moreover weakens the sensitivity of MGC803 and AGS cells to 5-Fu. We further demonstrated that miR-30a showed significantly lower expression in GC cells and inhibited the expression of DBF4 through 3ʹ-UTR suppression. Furthermore, rescue experiments revealed that the miR-30a-DBF4 axis regulated the GC cell proliferation, migration and the sensitivity to 5-Fu. The important composition in tumor microenvironment, lactate, may be the primary factor that suppressed miR-30a to strengthen the expression of DBF4.

Conclusions

Taken together, our study was the first to identify DBF4 as a regulator of cell proliferation and migration in GC. Furthermore, our study identified the lactate-miR-30a-DBF4 axis as a crucial regulator of tumor progression and the tumor sensitivity to 5-Fu, which maybe serve useful for the development of novel therapeutic targets.

miR-30b-5p inhibits cancer progression and enhances cisplatin sensitivity in lung cancer through targeting LRP8

Accumulated evidence has demonstrated that miRNAs are closely implicated in lung carcinogenesis. Herein, we explored the expression pattern of miR-30b-5p in lung cancer, and aimed to uncover miR-30b-5p roles in lung cancer progression and drug resistance. miR-30b-5p expression profiles in lung cancer tissues and the matched non-tumor tissues were determined by using qPCR. Cell viability, migration, invasion and in vivo tumorigenesis were determined by using the CCK-8, colony formation, wound healing, transwell chambers experiments and tumor xenograft models. RNA immunoprecipitation (RIP) and dual luciferase reporter experiments were applied to evaluate the relationship between miR-30b-5p and LRP8. The results demonstrated that miR-30b-5p showed a low expression profile in lung cancer tissues and cells, and closely linked to poor prognosis and malignant clinical process. Cell viability, migration, invasiveness and tumorigenesis were significantly weakened following miR-30b-5p overexpression in A549 and NCI-H1299 cells, while cell apoptosis rates were increased. In addition, miR-30b-5p was lowly expressed in A549/DDP (a cisplatin drug resistant cell line) as compared with A549 cells, and miR-30b-5p increased A549/DDP cell sensitivity to DDP. However, these above roles of miR-30b-5p were all significantly impaired following the overexpression of LRP8 which was overexpressed in lung cancer tissues. Collectively, this study demonstrated that miR-30b-5p functions as a tumor suppressor in lung cancer, and re-sensitizes lung cancer cells to DDP by targeting LRP8.

Roles and regulatory mechanisms of miR-30b in cancer, cardiovascular disease, and metabolic disorders (Review)

MicroRNAs (miRNAs) are non-coding RNAs 21-23 nucleotides in length that regulate gene expression, and thereby modulate signaling pathways and protein synthesis in both physiological and pathogenic processes. miR-30b inhibits cell proliferation, migration, invasion and epithelial-mesenchymal transformation in multiple types of cancer. In addition to its role in several types of neoplasias, miR-30b has been shown to exhibit essential roles in cardiovascular and metabolic diseases. In the present review, an overview of the biological functions of miR-30b and its role in the pathogenesis of neoplastic, cardiovascular and metabolic diseases is provided. miR-30b is a potential candidate for clinical development as a diagnostic and prognostic biomarker, therapeutic agent and drug target. However, further research is required to elucidate its role in health and disease and to harness its potential clinical utility.

Impaired cell migration and structural defects in myeloid cells overexpressing miR-30b and miR-142-3p

Macrophages (MΦ) and dendritic cells (DC) play a fundamental role in shaping immune responses by sensing a plethora of Pathogen Associated Molecular Patterns (PAMPs), phagocytosis and antigen presentation to T lymphocytes. These important biological processes require efficient cell movement and an intact cellular morphology for dynamic interaction. The role of microRNAs (miRs) in this regard, however, is not well understood. In the present study, we show that miR-30b and miR-142-3p regulate migration and morphology of MΦ and DC. Transient overexpression of miR-30b and miR-142-3p attenuates migration and these cells display unique morphological deformities observed under electron microscopy. In addition, miR-142-3p overexpression in MΦ impaired phagocytosis of FITC-conjugated latex beads using live microscopy imaging. Interestingly, live cell imaging and F-actin staining revealed marked changes in the cell polarity and actin polymerization status, respectively. To identify miR-142-3p regulated pathways, we profiled global transcriptome changes in miR-142-3p or control mimic transfected DC. Expression of several genes were differentially altered by miR-142-3p and were associated with pathways related to cell movement, cell adhesion, and cytoskeletal rearrangement. Bioinformatics analysis identified a significant subset of downregulated genes with one or more predicted miR-142-3p binding sites in their 3'UTR strongly suggesting direct post-transcriptional impact of these miRNAs on multiple transcripts. Using dual luciferase assays, novel miR-142-3p binding sites were validated for three genes (Vinculin, Dab2 and Skap2) directly associated with cytoskeletal rearrangement and cell movement. In summary, our results show that miR-30b and miR-142-3p are regulators of myeloid cell cytoskeletal homeostasis and morphology.

Aberrant methylation-mediated downregulation of lncRNA CCND2 AS1 promotes cell proliferation in cervical cancer

Background

Long non-coding RNA (lncRNA) plays an important role in tumorigenesis. The lncRNA CCND2 AS1 has been shown to be involved in the growth of several tumors; however, its role in cervical cancer has not been elucidated. This study aimed to explore the expression, function, and underlying mechanism of action of CCND2 AS1 in cervical cancer. Expression of CCND2 AS1 was examined in cervical cancer and adjacent normal cervical tissues by quantitative real-time polymerase chain reaction (qRT-PCR) and by bioinformatic analysis of data from the Gene Expression Profiling Interactive Analysis (GEPIA) database. The function of CCND2 AS1 was investigated by overexpressing or silencing CCND2 AS1 in HeLa and SiHa cervical cancer cells followed by in vitro and in vivo analyses. Methylation-specific PCR (MSP) and bisulfite genomic sequencing (BGS) were used to detect CCND2 AS1 promoter methylation status in cervical cancer cells.

Results

CCND2 AS1 expression was lower in cervical cancer compared with normal cervical tissues, and the level was significantly correlated with the patient age and tumor size. CCND2 AS1 overexpression inhibited the proliferation and cell cycle progression of HeLa cells in vitro and/or in vivo, whereas CCND2 AS1 silencing had the opposite effects. CCND2 AS1 expression was elevated after treatment of cervical cancer cells with the DNA methyltransferase inhibitor 5′-azacytidine (5′-Aza), and this was mediated, at least in part, via reduced CpG methylation at the CCND2 AS1 promoter.

Conclusion

CCND2 AS1 expression is downregulated in cervical cancer, potentially through increased CCND2 AS1 promoter methylation, and the upregulation of CCND2 AS1 expression inhibited tumor growth. These data suggest that CCND2 AS1 could be a diagnostic marker and potential therapeutic target for cervical cancer.

DNMT1: A key drug target in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. Altered epigenetics regulation including DNA hypermethylation by DNA methyltransferase 1 (DNMT1) has been implicated as one of the causes of TNBC tumorigenesis. In this review, the oncogenic functions rendered by DNMT1 in TNBCs, and DNMT1 inhibitors targeting TNBC cells are presented and discussed. In summary, DNMT1 expression is associated with poor breast cancer survival, and it is overexpressed in TNBC subtype. The oncogenic roles of DNMT1 in TNBCs include: (1) Repression of estrogen receptor (ER) expression; (2) Promotion of epithelial-mesenchymal transition (EMT) required for metastasis; (3) Induces cellular autophagy and; (4) Promotes the growth of cancer stem cells in TNBCs. DNMT1 confers these phenotypes by hypermethylating the promoter regions of ER, multiple tumor suppressor genes, microRNAs and epithelial markers involved in suppressing EMT. DNMT1 inhibitors exert anti-tumorigenic effects against TNBC cells. This includes the hypomethylating agents azacitidine, decitabine and guadecitabine that might sensitize TNBC patients to immune checkpoint blockade therapy. DNMT1 represents an epigenetic target for TNBC cells destruction as well as to derail their metastatic and aggressive phenotypes.

Down-regulation of miR-30b-5p protects cardiomyocytes against hypoxia-induced injury by targeting Aven

Background

Ischemia/hypoxia-induced cardiomyocyte apoptosis has been considered as a main cause of myocardial infarction. Here, we aimed to investigate the functional role of miR-30b-5p in hypoxic cardiomyocytes.

Methods

AC16 human cardiomyocytes were cultured under hypoxia to simulate myocardial infarction. A qRT-PCR assay was performed to determine miR-30b-5p expression in hypoxic cardiomyocytes. Cell survival, injury and apoptosis were assessed by MTT, lactate dehydrogenase (LDH) release, and flow cytometry assays, respectively. The target gene of miR-30b-5p in hypoxic cardiomyocytes was validated by luciferase reporter assay and Western blotting.

Results

MiR-30b-5p expression was found to be significantly upregulated in hypoxic AC16 cells. The in vitro experiments showed that downregulation of miR-30b-5p effectively alleviated hypoxia-induced cardiomyocyte injury. Furthermore, Aven is a potential target gene of miR-30b-5p and its downregulation could partially reverse the influence of miR-30b-5p knockdown on AC16 cells under hypoxia.

Conclusions

Inhibition of miR-30b-5p could protect cardiomyocytes against hypoxia-induced injury by targeting Aven.

Molecular characterization of lung cancer: A two-miRNA prognostic signature based on cancer stem-like cells related genes

Lung cancer is one of the deadliest cancers worldwide. To increase the survival rate of lung cancer, it is necessary to explore specific prognosis markers. More and more evidence finds that noncoding RNA is closely associated with the survival of lung cancer, and cancer stem cells (CSCs) also play a significant role in the progress of lung cancer. The objective of this study is to find CSLCs genes that affect the prognosis of lung cancer. The differential expression of long noncoding RNAs (lncRNAs), microRNAs (miRNAs), messenger RNAs (mRNAs) in the Cancer Genome Atlas (TCGA) database and differential expression data from microarray of CD326⁺ and CD326^- A549 cell are intersected to identify stable and consistent expression genes (2 lncRNAs, 15 miRNAs, and 134 mRNAs). The intersection of lncRNAs and miRNAs is analyzed by univariate and multivariate Cox regression to obtained prognostic genes. Two miRNAs (miR-30b-5p and miR-29c-3p) are significantly correlated with the overall survival rate. Then using these two miRNAs to construct a risk score model as a prognosis signature of lung cancer. Subsequently, we analyzed the association between two miRNAs and clinical information of lung cancer patients, of which T stage, Neoplasm cancer and risk score (P < .05) can be used as independent prognostic indicators of lung cancer. Finally, target genes of 2 miRNAs and 134 mRNAs were annotated with Gene Ontology and analyzed with Kyoto Encyclopedia of Genes and Genomes pathway, and verified with the GEO database. In summary, this study illustrates the role of miRNAs in the promotion of lung cancer by CSCs, which is important to find molecular biomarkers of lung cancer.

Differential Expression of Urinary Exosomal MicroRNAs miR-21-5p and miR-30b-5p in Individuals with Diabetic Kidney Disease

Biomarkers for the identification of diabetic kidney disease (DKD) are needed as current tests lack sensitivity for detecting early kidney damage. MicroRNAs (miRNAs) are short, non-coding regulatory ribonucleic acid (RNA) molecules commonly found in urinary exosomes differentially expressed as renal function declines. We evaluated urinary exosomal miRNA expression in persons with type 2 diabetes mellitus and DKD (T2DKD). 87 human urinary exosomal miRNAs were profiled in a discovery cohort of patients with T2DKD (n = 14) and age and gender matched controls with type 2 diabetes mellitus and normal renal function (T2DNRF; n = 15). Independent validation of differentially expressed target miRNAs was performed in a second cohort with T2DKD (n = 22) and two control groups: T2DNRF (n = 15) and controls with chronic kidney disease (CCKD) and poor renal function without diabetes (n = 18). In the discovery cohort, urinary miR-21-5p, let-7e-5p and miR-23b-3p were significantly upregulated in T2DKD compared to T2DNRF (p < 0.05). Conversely, miR-30b-5p and miR-125b-5p expression was significantly lower in T2DKD (p < 0.05). Independent validation confirmed up-regulation of miR-21-5p in the replication cohort in T2DKD (2.13-fold, p = 0.006) and in CCKD (1.73-fold, p = 0.024). In contrast, miR-30b-5p was downregulated in T2DKD (0.82-fold, p = 0.006) and in CCKD (0.66-fold, p < 0.002). This study identified differential expression of miR-21-5p and miR-30b-5p in individuals with diabetic kidney disease and poor renal function. These miRNAs represent potential biomarkers associated with the pathogenesis of renal dysfunction.

Non-coding RNAs in regulating gastric cancer metastasis

Gastric cancer is one of the leading causes of cancer-related deaths worldwide, and mortality remains high, especially in East Asia. At present, the main method to diagnose gastric cancer is pathological biopsy. At the time of diagnosis, most patients have been diagnosed with advanced cancer and metastasis. The treatment of gastric cancer patients is mainly radical surgical resection and chemoradiotherapy, while patients with metastatic tumor have great challenges to radical surgery and are prone to drug resistance. Metastasis is an important factor affecting tumor development. In addition, evidence accumulated in the literature indicates that non-coding RNA plays a key role in tumor metastasis. This article reviews the role of ncRNAs in gastric cancer metastasis and discusses the regulatory mechanism in the development and treatment of gastric cancer.

Regulatory Role of rno-miR-30b-5p in IL-10 and Toll-like Receptor 4 Expressions of T Lymphocytes in Experimental Autoimmune Uveitis In Vitro

Uveitis is a serious eye disease that usually damages young adult's health. MicroRNAs (miRNAs) are a class of small noncoding RNAs which regulate messenger RNA (mRNA) expression. It is predicted that rno-miR-30b-5p can regulate the expressions of interleukin-10 (IL-10) and Toll-like receptor 4 (TLR4). In this study, the regulatory role of rno-miR-30b-5p in IL-10 and TLR4 gene expressions was validated using luciferase activity assay. Further, the inflammatory manifestation of the anterior segment and pathological examination of the eye were explored in experimental autoimmune uveitis (EAU) rats. Meanwhile, the levels of rno-miR-30b-5p in eye tissues, spleen, and lymph nodes were measured using quantitative PCR (Q-PCR). IL-10 and TLR4 in spleen and lymph nodes were further separately determined by using Q-PCR and Enzyme-Linked Immunosorbent Assay (ELISA). Moreover, rno-miR-30b-5p mimic and its inhibitor were separately transfected into purified T cells, and the levels of IL-10 and TLR4 were detected using PCR, flow cytometry, and ELISA techniques. Results indicate that rno-miR-30b-5p was downregulated in spleen, lymph nodes, and eye tissues whereas the expressions of IL-10 and TLR4 at mRNA and protein levels were upregulated. The levels of IL-10 and TLR4 were negatively correlated to rno-miR-30b-5p levels. The result of in vitro cell transfection experiment indicates that IL-10 and TLR4 expressions were inhibited at mRNA and protein levels after T cells incubated with rno-miR-30b-5p mimic. However, the IL-10 and TLR4 mRNA levels were upregulated in purified T cells from spleen and lymph nodes after treatment with miR-30b-5p antagonist. In addition, there was no evident change of IL-10 and TLR4 proteins in spleen and lymph node T cells between EAU control and negative treatment groups. Flow cytometry analysis revealed that rno-miR-30b-5p mimic could reduce the number of both IL-10 and TLR4 positive cells, whereas rno-miR-30b-5p inhibitor could increase the number of IL-10 and TLR4 positive cells. Our study demonstrates that rno-miR-30b-5p influences the development of uveitis by regulating the level of IL-10 and TLR4 positive cells, thereby playing a role in the pathogenesis of uveitis.

MiR-30b-5p modulates glioma cell proliferation by direct targeting MTDH

Malignant glioma is the most common and lethal type of primary tumor of the central nervous system. The incidence of glioma is increasing year by year. In recent years, a variety of new treatment methods have emerged, among which gene therapy has become a hotspot. MicroRNAs (miRNAs) are a class of small non-coding single-strand RNAs that negatively regulate gene expression at the post-transcriptional and/or translational level by binding loosely complimentary sequences in the 3′ untranslated regions (UTRs) of target mRNAs. Several miRNAs have been reported to modulate glioma progression. This study aimed to determine the function of miR-30b-5p in glioma and its underlying molecular mechanism. miR-30b-5p expression was significantly lower in gliomas than the normal brain tissues. Overexpression of miR-30b-5p was found to significantly inhibit glioma cell proliferation in vitro. Further, MTDH expression was significantly higher in the gliomas compared with the normal brain tissues. In addition, MTDH was validated as direct target of miR-30b-5p. Moreover, cellular proliferation was increased after MTDH overexpression in the glioma cells, which reversed the effects of miR-30b-5p. Taken together, these results reveal miR-30b-5p impacts glioma cell proliferation via direct targeting MTDH and could be a potential novel therapeutic target for the treatment of glioma.

miR-133a acts as a tumor suppressor in colorectal cancer by targeting eIF4A1

Emerging evidence indicates that microRNAs play critical roles in carcinogenesis and cancer progression. In this study, miR-133a was found to be significantly downregulated in colon tumor tissues. We aimed to determine its biological function, molecular mechanisms, and direct target genes in colorectal cancer. From these results, we found that miR-133a was significantly downregulated in primary tumor tissues and colon cancer cell lines. Ectopic expression of miR-133a in colon cancer cell lines significantly suppressed cell growth, as evidenced by cell viability and colony formation assays, as well as reduced xenograft tumor growth in nude mice. However, the effect of miR-133a was abolished by the overexpression of eIF4A1. Moreover, miR-133a inhibited cellular migration and invasiveness. A luciferase activity assay revealed oncogene eukaryotic translation initiation factor 4A1 as a direct target gene of miR-133a, whose expression was inversely correlated with that of miR-133a. Our results demonstrate that miR-133a plays a pivotal role in colorectal cancer by inhibiting cell proliferation, invasion, and migration by targeting oncogenic eukaryotic translation initiation factor 4A1, which acts as a tumor suppressor and may provide a new potential therapeutic target in colorectal cancer.

MicroRNA-30a-5p inhibits the proliferation and invasion of gastric cancer cells by targeting insulin-like growth factor 1 receptor

MicroRNAs (miRs) are a class of small non-coding RNAs of 18–25 nucleotides in length that serve as key regulators in the development and progression of human cancers. Recently, miR-30b-5p, as a member of the miR-30 family, has been reported to act as a tumor suppressor in gastric cancer. However, the expression and function of miR-30a-5p in gastric cancer, as well as the corresponding underlying mechanism, remain unknown. In the present study, it was demonstrated that the expression of miR-30a-5p was significantly reduced in gastric cancer tissues (n=43) compared with normal gastric tissues (n=10; P<0.01). Similarly, miR-30a-5p was significantly downregulated in the gastric cancer cell lines AGS, HGC27, BGC823 and SGC7901, when compared with the normal gastric mucosa epithelial cell line GES-1 (P<0.01). In addition, overexpression of miR-30a-5p significantly inhibited the proliferation and invasion of AGS cells (P<0.01). Insulin-like growth factor 1 receptor (IGF-1R) was identified as a novel target of miR-30a-5p, and the protein expression of IGF-1R was negatively regulated by miR-30a-5p in AGS cells (P<0.01). Furthermore, overexpression of IGF-1R significantly reversed the inhibitory effect of miR-30a-5p on the proliferation and invasion of AGS cells (P<0.01), indicating that IGF-1R was involved in miR-30a-5p-mediated proliferation and invasion of AGS cells. It was also observed that the expression of IGF-1R mRNA was upregulated in gastric cancer tissues compared with normal gastric tissues (P<0.01), and its levels of expression were reversely correlated with that of miR-30a-5p in gastric cancer tissues (R²=0.3892; P<0.01). Collectively, these data suggest that miR-30a-5p inhibits the growth and metastasis of gastric cancer by directly targeting IGF-1R. Therefore, the miR-30a-5p/IGF-1R axis may be a potential therapeutic target in the treatment of gastric cancer.

MiR-30b-5p acts as a tumor suppressor, repressing cell proliferation and cell cycle in human hepatocellular carcinoma

MicroRNAs have been verified to participate in various biological behaviors of different tumors, via multiple signaling pathways. Many kinds of microRNAs in hepatocellular carcinoma have been researched. However, miR-30b-5p hasn't been included. Our study aim at the impacts of miR-30b-5p on HCC and the pathway it mediating. The results showed miR-30b-5p was significant downregulated in HCC tissues and cell lines. With clinical data, we've discovered miR-30b-5p was correlated with several clinical pathological characteristics, such as survival time, tumor size, HBV infected, pathological stage, differentiation and intrahepatic metastasis. Also we illustrated miR-30b-5p repressed cell proliferation and cell cycle of HCC cell lines. For a further study, we figured out that miR-30b-5p mediated DNMT3A to repress proliferation, meanwhile it targeted USP37 for decelerating cell cycle. This discovery inferred miR-30b-5p a potential favorable biomarker and therapeutic target for HCC diagnosis and treatment.

A Feedback Loop Between miR-30a/c-5p and DNMT1 Mediates Cisplatin Resistance in Ovarian Cancer Cells

BACKGROUND

Many microRNAs (miRs) are dysregulated in cancers, and aberrant miR expression patterns have been suggested to correlate with chemo-resistance of cancer cells. We aim to study the role of miR-30 family members in cisplatin-resistance of ovarian cancer cells.

METHODS

qRT-PCR was used to compare differential expression levels of miR-30 family members in ovarian cancer cell line A2780 and its cisplatin-resistant derivative CP70. Changes of cisplatin-sensitivity in miR-30a-5p- and miR-30c-5p-overexpressed-CP70 cells and miR-30a-5p- and miR-30c-5p-inhibited-A2780 cells were examined by CCK8 assay and apoptosis analysis using flow cytometry; targets of miR-30a/c-5p were analyzed by western blotting and luciferase reporter assay; methylation regulation of pre-miR-30a/c-5p was examined by methylation specific PCR.

RESULTS

miR-30a-5p and miR-30c-5p, in contrast to other miR-30 family members, dramatically decreased in cisplatin-resistant CP70 cells due to overexpressed-DNMT1 induced aberrant methylation. miR-30a/c-5p in turn directly inhibited DNMT1 as well as Snail. Forced expression of miR-30a/c-5p or knocking down of DNMT1 and Snail promoted cisplatin susceptibility and partially reversed epithelial-mesenchymal transition (EMT) in CP70 cells, while inhibition of miR-30a/c-5p or ectopic expression of DNMT1 and Snail induced cisplatin resistance and partial EMT in cisplatin-sensitive A2780 cells.

CONCLUSIONS

A feedback loop between miR-30a/c-5p and DNMT1 is a potent signature for cisplatin-resistance and EMT in ovarian cancer, promising a potential target for improved anti-cancer treatment.

Identification of miR‑30b as an oncogene in renal cell carcinoma

microRNAs (miRs) have been investigated as a novel class of regulators of cellular processes, including proliferation, apoptosis and metabolism. In particular, miR‑30b has been demonstrated to be deregulated in certain types of cancer, including lung, colorectal and gastric cancer. Previous studies of miR‑30b in renal clear cell carcinoma demonstrated that the expression level of miR‑30b was associated with distant metastasis. However, the function of miR‑30b in renal cell carcinoma (RCC) remained to be elucidated. In the present study, the expression of miR‑30b in 31 paired RCC tissues from four cell lines (786‑O, 769‑P, ACHN and 293T) was detected by reverse transcription‑quantitative polymerase chain reaction. In addition, the effect of miR‑30b on cell proliferation in RCC cells was also determined using MTT and Cell Counting Kit‑8 assay analyses. Furthermore, the function of miR‑30b in cell migration and invasion was determined by wound scratch and Transwell assays. Flow cytometry was also performed to quantify the effect of miR‑30b on cell apoptosis. The results of the current study indicated that miR‑30b was upregulated in RCC tissues from affected cell lines when compared with adjacent normal tissues and a normal kidney cell line, which is different to the downregulation of miR‑30b as observed in other types of cancer. miR‑30b is associated with RCC cell proliferation, invasion, migration and apoptosis, which indicated that miR‑30b acts as an oncogene in RCC. To the best of our knowledge, the present study is the first to demonstrate the upregulation of miR‑30b in RCC tissues and describe miR‑30b as an oncogene in RCC in the regulation of cell proliferation, migration, invasion and apoptosis. Further studies will define the target gene of miR‑30b in RCC and investigate the potential role of miR‑30b as a biomarker for RCC.

MiR-211 is epigenetically regulated by DNMT1 mediated methylation and inhibits EMT of melanoma cells by targeting RAB22A

MiR-211 has strong inhibitive effects on melanoma cell growth, invasion and metastasis. However, how it is downregulated and whether other genes are involved its downstream regulation in melanoma are not clear. In this study, we firstly verified the expression of miR-211 in melanoma cell lines and observed that its downregulation is associated with increased DNMT1 expression. By performing qRT-PCR and MSP analysis, we confirmed that DNMT1 is negatively correlated with miR-211 expression and can modulate DNA methylation in the promoter region of miR-211. By performing bioinformatics analysis, we found that RAB22A is a possible target of miR-211, which has two broadly conversed binding sites with miR-211 in the 3'UTR. Following dual luciferase assay, qRT-PCR and western blot analysis confirmed the direct binding between miR-211 and RAB22A and the suppressive effect of miR-211 on RAB22A expression. Knockdown of RAB22A increased epithelial properties and impaired mesenchymal properties of the melanoma cells, suggesting that miR-211 modulates epithelial mesenchymal transition (EMT) of melanoma cells via downregulating RAB22A. In summary, the present study firstly demonstrated that DNMT1 mediated promoter methylation is a mechanism of miRNA suppression in melanoma and revealed a new tumor suppressor role of the miR-211 by targeting RAB22A in melanoma. The DNMT1/miR-211/RAB22A axis provides a novel insight into the pathogenesis of melanoma, particularly in the EMT process.

The altered microRNA profile in andrographolide-induced inhibition of hepatoma tumor growth

BACKGROUND

MicroRNAs (miRNAs) have been reported to play critical roles in regulating gene expression in tumor development. Natural compound andrographolide (Andro), isolated from medicinal herb Andrographis paniculata, was reported to inhibit hepatoma tumor growth in our previous studies. The present study aims to observe the altered miRNAs profile and related signaling pathways involved in Andro-induced inhibition on hepatoma tumor growth.

RESULTS

The inhibition on hepatoma tumor growth induced by Andro (10mg/kg) was found in a xenograft mouse tumor model in vivo. The results of miRNAs chip analysis showed that the expression of 22 miRNAs was increased, whereas the expression of other 10 miRNAs was decreased after Andro treatment. Further, the increased expression of miR-222-3p, miR-106b-5p, miR-30b-5p, and miR-23a-5p was confirmed in hepatoma Hep3B and SMCC7721 cells in vitro after cells were treated with Andro (50μM) for the indicated time. Functional annotation of the target genes based on the differentially expressed miRNAs demonstrated that the majority of the genes were involved in a variety of signaling pathways, including miRNAs in cancer, mitogen-activated protein kinases (MPAKs), focal adhesion. Furthermore, the expression of 24 target genes (total 31) involved in above signaling pathways based on miRNAs analysis was found to be consistent with the alteration of miRNAs.

CONCLUSIONS

The results demonstrate that Andro alters the expression of miRNAs profile and downstream signals, which may contribute to its inhibition on hepatoma tumor growth.

Long non-coding RNA HNF1A-AS1 functioned as an oncogene and autophagy promoter in hepatocellular carcinoma through sponging hsa-miR-30b-5p

Long non-coding RNAs (lncRNAs) had been proved to be pivotal regulators in carcinogenesis. On the basis of competitive endogenous RNAs (ceRNAs) system, lncRNAs significantly expanded their regulating networks. In our research, we aimed to figure out the exact role of lncRNA HNF1A-AS1 in the pathogenesis of hepatocellular carcinoma (HCC), in a ceRNA-dependent way. First, we revealed: HNF1A-AS1 was frequently overexpressed in HCC tissues and cell lines and its relative high expression was closely related to larger tumor size, multiple tumor lesions, poor differentiation and advanced TNM stage. Then we found: HNF1A-AS1 functioned as an oncogene in tumor growth and apoptosis through sponging tumor-suppressive hsa-miR-30b-5p (miR-30b) and de-repressing Bcl-2. Further experiments identified: HNF1A-AS1-miR-30b axis significantly promoted autophagy under starvation and ATG5 was first proved to be a target of miR-30b. In summary, we identified HNF1A-AS1-miR-30b axis as a key regulator in hepatocarcinogenesis, which may be promising biomarkers and therapeutic targets in the future.

MiR-30b suppresses tumor migration and invasion by targeting EIF5A2 in gastric cancer

AIM

To elucidate the potential biological role of miR-30b in gastric cancer and investigate the underlying molecular mechanisms of miR-30b to inhibit metastasis of gastric cancer cells.

METHODS

The expression of miR-30b was detected in gastric cancer cell lines and samples by reverse transcription-polymerase chain reaction. CCK-8 assays were conducted to explore the impact of miR-30b overexpression on the proliferation of gastric cancer cells. Flow cytometry was used to examine the effect of miR-30b on the apoptosis. Transwell test was used for the migration and invasion assays. Luciferase reporter assays and Western blot were employed to validate regulation of putative target of miR-30b.

RESULTS

The results showed that miR-30b was downregulated in gastric cancer tissues and cancer cell lines and functioned as a tumor suppressor. Overexpression of miR-30b promoted cell apoptosis, and suppressed proliferation, migration and invasion of the gastric cancer cell lines AGS and MGC803. Bioinformatic analysis identified the 3'-untranslated region of eukaryotic translation initiation factor 5A2 (EIF5A2) as a putative binding site of miR-30b. Luciferase reporter assays and Western blot analysis confirmed the EIF5A2 gene as a target of miR-30b. Moreover, expression levels of the EIF5A2 targets E-cadherin and Vimentin were altered following transfection of miR-30b mimics.

CONCLUSION

Our findings describe a link between miR-30b and EIF5A2, which plays an important role in mediating epithelial-mesenchymal transition.

Chondromodulin-1 functions as a tumor suppressor in gastric adenocarcinoma

Chondromodulin-1 (ChM1) is a cartilage-specific glycoprotein that stimulates the growth of chondrocytes and inhibits the tube formation of endothelial cells. Endogenously, ChM1 is expressed in the cartilage and is an anti-angiogenic factor. ChM1 has been reported to suppress the proliferation of multiple human tumor cells in an anchorage-independent manner. However, the role of ChM1 in carcinogenesis of gastric cancer remains unknown. By quantitative RT-PCR and western blotting we examined the expression of ChM1 in gastric cancer tissue and normal gastric tissue. In vitro we investigated the functional and mechanistic roles of ChM1 in the inhibition of gastric cancer cell aggressiveness. We observed that ChM1 expression was remarkably downregulated in gastric cancer cell lines compared with the immortal normal gastric epithelial cell line GES-1. Importantly, ChM1 was frequently downregulated in gastric cancer tissue compared with normal gastric tissue. Low ChM1 mRNA expression was associated with higher clinical stages, higher lymph node metastasis, and poorer prognosis of patients. Functional assays in vitro showed that ectopic expression of ChM1 was able to inhibit gastric tumor cell proliferation by arresting the cell cycle. Overall, our findings indicate that ChM1 is a potential tumor suppressor in gastric cancer, suggesting that it may be useful as a biomarker for the treatment and prognosis of gastric cancer.

MicroRNA-25 promotes gastric cancer proliferation, invasion, and migration by directly targeting F-box and WD-40 Domain Protein 7, FBXW7

Increasing evidence shows that abnormal microRNA (miRNA) expression is involved in tumorigenesis. MiR-25 was previously reported to act as tumor suppressor or oncogene in diverse cancers. However, their expression, function, and mechanism in gastric cancer (GC) are not well known. Here, we show that miR-25 was overexpressed in primary tumor tissues of GC patients and was significantly correlated with a more aggressive phenotype of GC in patients. MiR-25 inhibition significantly decreased the proliferation, invasion, and migration of GC cells in vitro. Furthermore, miR-25 repressed F-box and WD-40 domain protein 7 (FBXW7) expression by directly binding to 3-untranslated region (UTR) of FBXW7, and the inverse correlation was observed between the expressions of miR-25 and FBXW7 mRNA in primary GC tissues. Moreover, the restoration of FBXW7 led to suppressed proliferation, invasion, and migration of GC cells. In vivo, miR-25 promotes tumor growth of GC. Taken together, miR-25 promotes GC progression by directly downregulating FBXW7 expression and may be employed as a novel prognostic marker and therapeutic target of GC.

The miR-30 Family Inhibits Pulmonary Vascular Hyperpermeability in the Premetastatic Phase by Direct Targeting of Skp2

PURPOSE

Before metastasis, primary tumor can create a premetastatic niche in distant organ to facilitate the dissemination of tumor cells. In the premetastatic phase, the permeability of pulmonary vasculatures is increased to accelerate the extravasation of circulating tumor cells. However, it is not clear whether local miRNAs contribute to the vascular hyperpermeability of the premetastatic niche.

EXPERIMENTAL DESIGN

The expression of total miRNAs was determined using microarray in series of premetastatic lungs from tumor-bearing mice. Significantly differentially expressed miRNAs were identified and validated with qRT-PCR. Vascular permeability assays, vascular mimic systems, and orthotopic tumor models were used to investigate roles of selected miRNAs and target genes in premetastatic hyperpermeability.

RESULTS

We identified a miRNA signature in premetastatic lungs. Among these miRNAs, miR-30a, b, c, d, and e were significantly attenuated. Subsequent investigations elucidated that lung fibroblast-derived miR-30s stabilized pulmonary vessels. Overexpression of miR-30s in lungs postponed metastasis and extended overall survival of B16 tumor-bearing mice. Following studies uncovered that Skp2 was directly targeted by miR-30s. Overexpression of Skp2 could disrupt pulmonary vessels, promote lung metastasis, and decrease overall survival of B16 tumor-bearing mice.

CONCLUSIONS

These findings illuminate a novel mechanism for the modulation of premetastatic niches by miR-30s, which suggest that miR-30s represent not only promising targets for antimetastasis therapy but also indicators for metastasis.

miR-30b, down-regulated in gastric cancer, promotes apoptosis and suppresses tumor growth by targeting plasminogen activator inhibitor-1

Background

Gastric cancer is one of the most common malignant diseases worldwide. Emerging evidence has shown that microRNAs (miRNAs) are associated with tumor development and progression. Our previous studies have revealed that H. pylori infection was able to induce the altered expression of miR-30b in gastric epithelial cells. However, little is known about the potential role of miR-30b in gastric cancer.

Methods

We analyzed the expression of miR-30b in gastric cancer cell lines and human gastric cancer tissues. We examined the effect of miR-30b mimics on the apoptosis of gastric cancer cells in vitro by flow cytometry (FCM) and caspase-3/7 activity assays. Nude mouse xenograft model was used to determine whether miR-30b is involved in tumorigenesis of gastric cancer. The target of miR-30b was identified by bioinformatics analysis, luciferase assay and Western blot. Finally, we performed the correlation analysis between miR-30b and its target expression in gastric cancer.

Results

miR-30b was significantly down-regulated in gastric cancer cells and human gastric cancer tissues. Enforced expression of miR-30b promoted the apoptosis of gastric cancer cells in vitro, and miR-30b could significantly inhibit tumorigenicity of gastric cancer by increasing the apoptosis proportion of cancer cells in vivo. Moreover, plasminogen activator inhibitor-1 (PAI-1) was identified as the potential target of miR-30b, and miR-30b level was inversely correlated with PAI-1 expression in gastric cancer. In addition, silencing of PAI-1 was able to phenocopy the effect of miR-30b overexpression on apoptosis regulation of cancer cells, and overexpression of PAI-1 could suppressed the effect of promoting cell apoptosis by miR-30b, indicating PAI-1 is potentially involved in miR-30b-induced apoptosis on cancer cells.

Conclusion

miR-30b may function as a novel tumor suppressor gene in gastric cancer by targeting PAI-1 and regulating the apoptosis of cancer cells. miR-30b could serve as a potential biomarker and therapeutic target against gastric cancer.