Down-Regulated miR-30a in Clear Cell Renal Cell Carcinoma Correlated with Tumor Hematogenous Metastasis by Targeting Angiogenesis-Specific DLL4

The Neoangiogenic Transcriptomic Signature Impacts Hepatocellular Carcinoma Prognosis and Can Be Triggered by Transarterial Chemoembolization Treatment

Background/Objectives: We evaluated the relationship between the neoangiogenic transcriptomic signature (nTS) and clinical symptoms, treatment outcomes, and survival in hepatocellular carcinoma (HCC) patients. Methods: This study prospectively followed 328 patients in the derivation and 256 in the validation cohort (with a median follow-up of 31 and 22 months, respectively). The nTS was associated with disease presentation, treatments administered, and overall survival rates. Additionally, this study investigated how multiple treatments influenced changes in nTS status and alterations in microRNA expression. Results: The nTS was identified in 27.4% of patients, linked to aggressive features like multifocality and elevated alpha-fetoprotein (AFP), a pattern consistent with that of the validation cohort. Most patients in both cohorts received treatment for HCC. nTS+ patients had limited access to, and benefited less from, liver transplantation or radiofrequency ablation (RFA) compared to nTS- patients. By the end, 78.9% had died, with nTS- patients showing better median survival and response to treatments than their nTS+ counterparts, who had lower survival across all treatment types. Among those who received transarterial chemoembolization (TACE), 31.2% (21/80 patients after the initial treatment and another four following a second TACE) transitioned from an nTS- to an nTS+ status. This shift was associated with lower survival and alterations in microRNA expressions related to oncogenic pathways. Conclusions: The nTS markedly influences treatment eligibility and survival in patients with HCC. Notably, the nTS can develop after repeated TACE procedures, significantly impacting patient survival and altering oncogenic microRNA expression patterns. These findings highlight the critical role of the nTS in guiding treatment decisions and prognostication in HCC management.

Apolipoprotein L1 is a tumor suppressor in clear cell renal cell carcinoma metastasis

The 5-year survival rate of kidney cancer drops dramatically from 93% to 15% when it is metastatic. Metastasis constitutes for 30% of kidney cancer cases, in which clear cell renal cell carcinoma (ccRCC) is the most prominent subtype. By sequencing mRNA of ccRCC patient samples, we found that apolipoprotein L1 (APOL1) was highly expressed in tumors compared to their adjacent normal tissues. This gene has been previously identified in a large body of kidney disease research and was reported as a potential prognosis marker in many types of cancers. However, the molecular function of APOL1 in ccRCC, especially in metastasis, remained unknown. In this study, we modulated the expression of APOL1 in various renal cancer cell lines and analyzed their proliferative, migratory, and invasive properties. Strikingly, APOL1 overexpression suppressed ccRCC metastasis both in vitro and in vivo. We then explored the mechanism by which APOL1 alleviated ccRCC malignant progression by investigating its downstream pathways. APOL1 overexpression diminished the activity of focal adhesive molecules, Akt signaling pathways, and EMT processes. Furthermore, in the upstream, we discovered that miR-30a-3p could inhibit APOL1 expression. In conclusion, our study revealed that APOL1 play a role as a tumor suppressor in ccRCC and inhibit metastasis, which may provide novel potential therapeutic approaches for ccRCC patients.

LncRNA H19 promotes tumor angiogenesis in smokers by targeting anti-angiogenic miRNAs

A key concept in drug discovery is the identification of candidate therapeutic targets such as long noncoding RNAs (lncRNAs) because of their extensive involvement in neoplasms, and impressionability by smoking. Induced by exposure to cigarette smoke, lncRNA H19 targets and inactivates miR-29, miR-30a, miR-107, miR-140, miR-148b, miR-199a and miR-200, which control the rate of angiogenesis by inhibiting BiP, DLL4, FGF7, HIF1A, HIF1B, HIF2A, PDGFB, PDGFRA, VEGFA, VEGFB, VEGFC, VEGFR1, VEGFR2 and VEGFR3. Nevertheless, these miRNAs are often dysregulated in bladder cancer, breast cancer, colorectal cancer, glioma, gastric adenocarcinoma, hepatocellular carcinoma, meningioma, non-small-cell lung carcinoma, oral squamous cell carcinoma, ovarian cancer, prostate adenocarcinoma and renal cell carcinoma. As such, the present perspective article seeks to establish an evidence-based hypothetical model of how a smoking-related lncRNA known as H19 might aggravate angiogenesis by interfering with miRNAs that would otherwise regulate angiogenesis in a nonsmoking individual.

Epigenetically-regulated miR-30a/c-5p directly target TWF1 and hamper ccRCC cell aggressiveness

Clear cell renal cell carcinoma (ccRCC) is highly prone to metastasize and displays an extremely low 5-year survival rate. Not only miRNAs (miRs) are key gene expression regulators but can also be epigenetically modified. Abnormal miR expression has been linked with epithelial-mesenchymal transition (EMT)-driven ccRCC progression. MiR-30a/c-5p were found downregulated in ccRCC and associated with aggressiveness. Herein, we sought to unravel miR-30a/c-5p mechanistic role in ccRCC. RNA sequencing and genome-wide methylome data of ccRCC and normal tissue samples from The Cancer Genome Atlas database were integrated to identify candidate miRs cytosine-phosphate-guanine (CpG) loci deregulated in ccRCC. TargetScan was searched to identify miR putative targets. MiR-30a/c-5p expression and promoter methylation was evaluated in vitro, by PCR. Western blot, functional and luciferase assays were performed after cell transfection with either pre-miR, antimiR, or siRNA against twinfilin-1 (TWF1). Immunohistochemistry (IHC) was performed in ccRCC tissues. We found miR-30c-5p downregulation and aberrant promoter methylation in ccRCC tissues. In vitro studies revealed concomitant miR-30a/c-5p downregulation and increased promoter methylation, as well as a significant re-expression following decitabine treatment. Functional assays demonstrated that both miRs significantly decreased cell aggressiveness and the protein levels of EMT-promoting players, while upregulating epithelial markers, namely Claudin-1 and ZO-1. Importantly, we confirmed TWF1 as a direct target of both miRs, and its potential involvement in epithelial-mesenchymal transition/mesenchymal-epithelial transition regulation. IHC analysis revealed higher TWF1 expression in primary tissues from patients that developed metastases, after surgical treatment. Our results implicate miR-30a/c-5p in ccRCC cells' aggressiveness attenuation by directly targeting TWF1 and hampering EMT.

Atractylenolide III Attenuates Angiogenesis in Gastric Precancerous Lesions Through the Downregulation of Delta-Like Ligand 4

Background: Blocking and even reversing gastric precancerous lesions (GPL) is a key measure to lower the incidence of gastric cancer. Atractylenolide III (AT-III) is a mainly active component of the Atractylodes rhizome and has been widely used in tumor treatment. However, the effects of AT-III on GPL and its mechanisms have not been reported.

Methods: H & E staining and AB-PAS staining were employed to evaluate the histopathology in the gastric mucosa. In parallel, CD34 immunostaining was performed for angiogenesis assessment, and transmission electron microscope for microvessel ultrastructural observation. Investigation for the possible mechanism in vivo and in vitro was conducted using immunohistochemistry, RT-qPCR and western blotting.

Results: In most GPL specimens, AT-III treatment reduced microvascular abnormalities and attenuated early angiogenesis, with the regression of most intestinal metaplasia and partial dysplasia. Meanwhile, the expression of VEGF-A and HIF-1α was enhanced in GPL samples of model rats, and their expressions were decreased in AT-III-treated GPL rats. Moreover, DLL4 mRNA and protein expression were higher in GPL rats than in control rats. DLL4 protein expression was significantly enhanced in human GPL tissues. In addition, AT-III treatment could diminish DLL4 mRNA level and protein expression in the MNNG-induced GPL rats. In vitro study showed that in AGS and HGC-27 cells, DLL4 mRNA level and protein expression were significantly decreased after AT-III treatment. However, AT-III had no significant regulatory effect on Notch1 and Notch4.

Conclusion: AT-III treatment is beneficial in lessening gastric precancerous lesions and attenuating angiogenesis in rats, and that may be contributed by the decrease of angiogenesis-associated HIF-1α and VEGF-A, and downregulation of DLL4.

miR-30c inhibits angiogenesis by targeting delta-like ligand 4 in liver sinusoidal endothelial cell to attenuate liver fibrosis

Liver fibrosis is a common feature of liver dysfunction during chronic liver diseases and is frequently associated with angiogenesis, a dynamic process that forms new blood vessels from preexisting vasculature. MicroRNAs (miRNAs), which act as posttranscriptional regulators of gene expression, have been shown to regulate liver fibrosis; however, how miRNAs regulate angiogenesis and its mechanism in fibrosis are not well understood. We aimed to elucidate the role and mechanism of miR-30c in attenuating liver fibrosis. Using miRNA profiling of fibrotic murine livers, we identified differentially regulated miRNAs and discovered that miR-30c is aberrantly expressed and targets endothelial delta-like ligand 4 (DLL4) in either carbon tetrachloride-treated or bile duct ligated fibrotic mice, as well as in patients with liver fibrosis. Using CCK-8, wound healing and Matrigel tube formation assays, we found that miR-30c inhibited liver sinusoidal endothelial cell (LSEC) proliferation, migration, and angiogenesis capacity by targeting DLL4 in vitro. Importantly, nanoparticle-based delivery of miR-30c to LSECs inhibited the DLL4/Notch pathway and angiogenesis, thereby ameliorating liver fibrosis in vivo. Collectively, our findings demonstrate a protective role of miR-30c in liver fibrosis by regulating DLL4/Notch signaling and angiogenesis. Thus, miR-30c may serve as a potential treatment for chronic liver diseases.

MITF Promotes Cell Growth, Migration and Invasion in Clear Cell Renal Cell Carcinoma by Activating the RhoA/YAP Signal Pathway

Simple Summary

Microphthalmia-associated transcription factor (MITF) has been reported to play a role in the progression of melanoma and other cancer types. However, the biological role of MITF in clear cell renal cell carcinoma (ccRCC) is largely unknown. In this study, we elucidate the role of MITF in the progression of ccRCC. MITF- and MITF-mediated signaling pathways were investigated in ccRCC cell through MITF knockdown as well as overexpression of MITF in vitro and in vivo. MITF contributed to cell proliferation, migration, invasion and tumor growth in ccRCC through activation of the RhoA/YAP signaling pathways. This study suggests that MITF has potential as a therapeutic target in ccRCC.

Abstract

Microphthalmia-associated transcription factor (MITF) is a basic helix-loop-helix leucine zipper transcription factor involved in the lineage-specific regulation of melanocytes, osteoclasts and mast cells. MITF is also involved in the progression of melanomas and other carcinomas, including the liver, pancreas and lung. However, the role of MITF in clear cell renal cell carcinoma (ccRCC) is largely unknown. This study investigates the functional role of MITF in cancer and the molecular mechanism underlying disease progression in ccRCC. MITF knockdown inhibited cell proliferation and shifted the cell cycle in ccRCC cells. In addition, MITF knockdown reduced wound healing, cell migration and invasion compared with the controls. Conversely, MITF overexpression in SN12C and SNU482 cells increased cell migration and invasion. Overexpression of MITF activated the RhoA/YAP signaling pathway, which regulates cell proliferation and invasion, and increased YAP signaling promoted cell cycle-related protein expression. Additionally, tumor formation was impaired by MITF knockdown and enhanced by MITF overexpression in vivo. In summary, MITF expression was associated with aggressive tumor behavior, and increased the migratory and invasive capabilities of ccRCC cells. These effects were reversed by MITF suppression. These results suggest that MITF is a potential therapeutic target for the treatment of ccRCC.

MiR-30a sensitized lung cancer against neoadjuvant chemotherapy by depressing autophagy

OBJECTIVE

This study was aimed at exploring whether miR-30a enhanced sensitivity of non-small-cell lung cancer (NSCLC) cells against neoadjuvant chemotherapy through an autophagy-dependent way.

METHODS

We totally recruited 304 NSCLC patients who have underwent chemotherapy, as well as 185 NSCLC patients who did not receive chemotherapy. NSCLC cell lines (i.e. H1299 and H460) were also purchased, and they were transfected by miR-30a mimic/inhibitor. Furthermore, cisplatin (DDP)/pemetrexed (PEM) resistance of NSCLC cells was assessed utilizing MTT assay, and autophagic proteins isolated from NSCLC tissues and cells were quantitated by western blotting.

RESULTS

Lowly expressed miR-30a was reflective of lymph node metastasis, advanced TNM stage and poor 5-year survival among NSCLC patients treated by neoadjuvant chemotherapy (i.e. combined treatment of DDP and PEM) (P < 0.05). Moreover, DDP combined with PEM attenuated viability and proliferation, but, on the contrary, promoted autophagy of H1299 and H460 cell lines (P < 0.05). However, miR-30a undermined resistance of NSCLC cells against DDP and PEM (P < 0.05), and it suppressed DDP/PEM-induced autophagy and promoted DDP/PEM-triggered apoptosis of NSCLC cells (P < 0.05).

CONCLUSIONS

Intentionally elevating miR-30a expression was conducive to improving NSCLC prognosis after neoadjuvant chemotherapy, for its depressing drug-caused autophagy and resistance.

The role of Notch ligand, Delta-like ligand 4 (DLL4), in cancer angiogenesis—implications for therapy

Background

It is generally accepted that angiogenesis is a complex and tightly regulated process characterized by the growth of blood vessels from existing vasculature. Activation of the Notch signalling pathway affects multiple aspects of vascular development. One of the components of the Notch signalling pathway, Delta-like ligand 4 (DLL4), has recently appeared as a critical regulator of tumour angiogenesis and thus as a promising therapeutic target.

Methods

This review article includes available data from peer-reviewed publications associated with the role of DLL4 in cancer angiogenesis. Searches were performed in PubMed, EMBASE, Google Scholar and Web of Science using the terms “tumour angiogenesis”, “DLL4”, “Notch signalling” and “anti-cancer therapy”.

Results

The survival curves of cancer patients revealed that the patients with high DLL4 expression levels had significantly shorter survival times than the patients with low DLL4 expression. Moreover, a positive correlation was also identified between DLL4 and VEGF receptorsʼ expression levels. It seems that inhibition of DLL4 may exert potent growth inhibitory effects on some tumours resistant to anti-VEGF therapies. A great number of blocking agents of DLL4/Notch signalling including anti-DLL4 antibodies, DNA vaccination, Notch antibodies and gamma-secretase inhibitors have been studied in preclinical tumour models.

Conclusion

DLL4 seems to be a promising target in anti-cancer therapy. Nevertheless, the careful evaluation of adverse effects on normal physiological processes in relation to therapeutic doses of anti-DLL4 drugs will be significant for advancement of DLL4 blocking agents in clinical oncology.

The Ambivalent Role of miRNAs in Carcinogenesis: Involvement in Renal Cell Carcinoma and Their Clinical Applications

The analysis of microRNA (miRNAs), small, non-coding endogenous RNA, plays a crucial role in oncology. These short regulatory sequences, acting on thousands of messenger RNAs (mRNAs), modulate gene expression at the transcriptional and post-transcriptional level leading to translational repression or degradation of target molecules. Although their function is required for several physiological processes, such as proliferation, apoptosis and cell differentiation, miRNAs are also responsible for development and/or progression of several cancers, since they may interact with classical tumor pathways. In this review, we highlight recent advances in deregulated miRNAs in cancer focusing on renal cell carcinoma (RCC) and provide an overview of the potential use of miRNA in their clinical settings, such as diagnostic and prognostic markers.

Systematic Analysis of microRNA Biomarkers for Diagnosis, Prognosis, and Therapy in Patients With Clear Cell Renal Cell Carcinoma

The ever-increasing morbidity and mortality of clear cell renal cell carcinoma (ccRCC) urgently demands updated biomarkers. MicroRNAs (miRNAs) are involved in diverse biological processes such as cell proliferation, differentiation, apoptosis by regulating their target genes' expression. In kidney cancers, miRNAs have been reported to be involved in tumorigenesis and to be the diagnostic, prognostic, and therapeutic response biomarkers. Here, we performed a systematic analysis for ccRCC-related miRNAs as biomarkers by searching keywords in the NCBI PubMed database and found 118 miRNAs as diagnostic biomarkers, 28 miRNAs as prognostic biomarkers, and 80 miRNAs as therapeutic biomarkers in ccRCC. miRNA-21, miRNA-155, miRNA-141, miRNA-126, and miRNA-221, as significantly differentially expressed miRNAs between cancer and normal tissues, play extensive roles in the cell proliferation, differentiation, apoptosis of ccRCC. GO and KEGG enrichment analysis of these miRNAs' target genes through Metascape showed these target genes are enriched in Protein Domain Specific Binding (GO:0019904). In this paper, we identified highly specific miRNAs in the pathogenesis of ccRCC and explored their potential applications for diagnosis, prognosis, and treatment of ccRCC.

MicroRNA-30a-5pme: a novel diagnostic and prognostic biomarker for clear cell renal cell carcinoma in tissue and urine samples

Background

The rising incidence of renal cell carcinomas (RCC) constitutes a significant challenge owing to risk of overtreatment. Because aberrant microRNA (miR) promoter methylation contributes to cancer development, we investigated whether altered miR-30a-5p expression associates with DNA promoter methylation and evaluated the usefulness as clear cell RCC (ccRCC) diagnostic and prognostic markers.

Methods

Genome-wide methylome and RNA sequencing data from a set of ccRCC and normal tissue samples from The Cancer Genome Atlas (TCGA) database were integrated to identify candidate CpG loci involved in cancer onset. MiR-30a-5p expression and promoter methylation were quantitatively assessed by PCR in a tissue set (Cohort #1) and urine sets (Cohorts #2 and 3) from IPOPorto and Homburg University Hospital. Non-parametric tests were used for comparing continuous variables. MiR-30a-5p promoter methylation (miR-30a-5p^me) performance as diagnostic (receiver operator characteristics [ROC] - validity estimates) and prognostic [metastasis-free (MFS) and disease-specific survival (DSS)] biomarker was further validated in urine samples from ccRCC patients by Kaplan Meier curves (with log rank) and both univariable and multivariable analysis.

Results

Two significant hypermethylated CpG loci in TCGA ccRCC samples, correlating with miR-30a-5p transcriptional downregulation, were disclosed. MiR-30a-5p^me in ccRCC tissues was confirmed in an independent patient’s cohort of IPOPorto and associated with shorter time to relapse. In urine samples, miR-30a-5p^me levels identified cancer both in testing and validation cohorts, with 83% sensitivity/53% specificity and 63% sensitivity/67% specificity, respectively. Moreover, higher miR-30a-5p^me levels independently predicted metastatic dissemination and survival.

Conclusion

To the best of our knowledge, this is the first study validating the diagnostic and prognostic potential of miR-30a-5p^me for ccRCC in urine samples, providing new insights for its clinical usefulness as non-invasive cancer biomarker.

The Role of DLLs in Cancer: A Novel Therapeutic Target

Delta-like ligands (DLLs) control Notch signaling. DLL1, DLL3 and DLL4 are frequently deregulated in cancer and influence tumor growth, the tumor vasculature and tumor immunity, which play different roles in cancer progression. DLLs have attracted intense research interest as anti-cancer therapeutics. In this review, we discuss the role of DLLs in cancer and summarize the emerging DLL-relevant targeting methods to aid future studies.

TNFAIP8 promotes the migration of clear cell renal cell carcinoma by regulating the EMT

Background: Clear cell renal cell carcinoma (ccRCC) is characterized by high metastatic potential, and the epithelial-mesenchymal transition (EMT) has been shown to play a key role in multiple cancer progression, migration and metastasis and is the leading cause of poor prognosis. Currently, tumor necrosis factor-α-induced protein 8 (TNFAIP8/TIPE) is a newly discovered tumorigenesis factor, and TNFAIP8 and the EMT influence the migration of renal cancer cells.

Methods: In this study, we first analyzed the relationship between TNFAIP8 and ccRCC using bioinformatics, followed by immunohistochemistry to evaluate the relationship between the two in clinical samples. Subsequently, reverse transcription PCR and western blotting confirmed the expression of TNFAIP8 in ccRCC cells. Furthermore, we measured the migration and invasion abilities by using wound healing and transwell assays after overexpression or knockdown of TNFAIP8 in cells. In addition, we verified whether TNFAIP8 affects the EMT process in ccRCC by quantitative real-time PCR, western blotting, immunohistochemistry and immunofluorescence experiments.

Results: Through database analysis, we found that TNFAIP8 was highly expressed in ccRCC patients and was positively correlated with tumor stage and grade, indicating that TNFAIP8 is associated with the development of advanced ccRCC and poor prognosis. We subsequently confirmed that TNFAIP8 was abnormally overexpressed in clinical samples and ccRCC cell lines and that TNFAIP8 promoted ccRCC cell migration and invasion in vitro. Finally, we found that TNFAIP8 regulated EMT-related molecule expression and regulated the EMT process.

Conclusion: High expression of TNFAIP8 reinforces migration and regulates the EMT in ccRCC, conferring the metastatic potential of ccRCC and suggesting that TNFAIP8 may be a potential therapeutic target for the treatment of advanced ccRCC.

Aberrant Expression of miR-592 Is Associated with Prognosis and Progression of Renal Cell Carcinoma

Purpose

MicroRNAs have recently reported playing a vital role in the development of cancers. However, the role of miR-592 in renal cell carcinoma (RCC) has not been explored. In this study, the potential role of miR-592 was investigated in RCC.

Patients and methods

The expression of miR-592 was evaluated in RCC tissues and cell lines using qRT-PCR assays. The Kaplan-Meier analysis and Cox proportional hazards model analysis was used to analyze the prognostic value of miR-592 in RCC. The effects of miR-592 on cell proliferation, migration, and invasion were determined by cell counting kit-8 (CCK-8) and Transwell assays in vitro.

Results

The results showed that miR-592 was significantly increased both in RCC tissues and cell lines. Overexpression of miR-592 was significantly associated with lymph node metastasis, TNM stage, and poor overall survival. And functional studies in two RCC cell lines (786-O and Caki-1) have shown that overexpression of miR-592 promoted cell proliferation, migration, and invasion, while silence of miR-592 inhibited cell proliferation, migration, and invasion. SPRY2 was a direct target of miR-592.

Conclusion

Overall, overexpression of miR-592 may be a prognostic biomarker and therapeutic strategy for patients with RCC, which is correlated with the progression of RCC.

Molecular Mechanisms in Clear Cell Renal Cell Carcinoma: Role of miRNAs and Hypermethylated miRNA Genes in Crucial Oncogenic Pathways and Processes

Clear cell renal cell carcinoma (ccRCC) is the third most common urological cancer, and it has the highest mortality rate. The increasing drug resistance of metastatic ccRCC has resulted in the search for new biomarkers. Epigenetic regulatory mechanisms, such as genome-wide DNA methylation and inhibition of protein translation by interaction of microRNA (miRNA) with its target messenger RNA (mRNA), are deeply involved in the pathogenesis of human cancers, including ccRCC, and may be used in its diagnosis and prognosis. Here, we review oncogenic and oncosuppressive miRNAs, their putative target genes, and the crucial pathways they are involved in. The contradictory behavior of a number of miRNAs, such as suppressive and anti-metastatic miRNAs with oncogenic potential (for example, miR-99a, miR-106a, miR-125b, miR-144, miR-203, miR-378), is examined. miRNAs that contribute mostly to important pathways and processes in ccRCC, for instance, PI3K/AKT/mTOR, Wnt-β, histone modification, and chromatin remodeling, are discussed in detail. We also separately consider their participation in crucial oncogenic processes, such as hypoxia and angiogenesis, metastasis, and epithelial-mesenchymal transition (EMT). The review also considers the interactions of long non-coding RNAs (lncRNAs) and miRNAs of significance in ccRCC. Recent advances in the understanding of the role of hypermethylated miRNA genes in ccRCC and their usefulness as biomarkers are reviewed based on our own data and those available in the literature. Finally, new data and perspectives concerning the clinical applications of miRNAs in the diagnosis, prognosis, and treatment of ccRCC are discussed.

Atractylenolide II reverses the influence of lncRNA XIST/miR-30a-5p/ROR1 axis on chemo-resistance of colorectal cancer cells

This investigation was conducted to elucidate whether atractylenolide II could reverse the role of lncRNA XIST/miR-30a-5p/ROR1 axis in modulating chemosensitivity of colorectal cancer cells. We totally collected 294 pairs of colorectal cancer tissues and adjacent normal tissues and also purchased colorectal cancer cell lines and human embryonic kidney cell line. 5-fluorouracil, cisplatin, mitomycin and adriamycin were designated as the chemotherapies for colorectal cell lines, and atractylenolides were arranged as the Chinese drug. The expressions of XIST, miR-30a-5p and ROR1 were quantified with aid of qRT-PCR or Western blot, and luciferase reporter gene assay was implemented to determine the relationships among XIST, miR-30a-5p and ROR1. Our results demonstrated that XIST and ROR1 expressions were dramatically up-regulated, yet miR-30a-5p expression was down-regulated within colorectal cancer tissues (P < 0.05). The overexpressed XIST and ROR1, as well as under-expressed miR-30a-5p, were inclined to promote viability and proliferation of colorectal cells under the influence of chemo drugs (P < 0.05). In addition, XIST could directly target miR-30a-5p, and ROR1 acted as the targeted molecule of miR-30a-5p. Interestingly, atractylenolides not only switched the expressions of XIST, miR-30a-5p and ROR1 within colorectal cancer cells but also significantly intensified the chemosensitivity of colorectal cancer cells (P < 0.05). Finally, atractylenolide II was discovered to slow down the viability and proliferation of colorectal cancer cells (P < 0.05). In conclusion, the XIST/miR-30a-5p/ROR1 axis could be deemed as pivotal markers underlying colorectal cancer, and administration of atractylenolide II might improve the chemotherapeutic efficacy for colorectal cancer.

MicroRNA-218 inhibits the cell proliferation and migration in clear cell renal cell carcinoma through targeting cancerous inhibitor of protein phosphatase 2A

MicroRNAs (miRs) have emerged as critical modulators of tumor initiation and progression in numerous types of human cancer, including clear cell renal cell carcinoma (ccRCC), which is the most common subtype of renal cell carcinoma. Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a newly characterized oncoprotein and its overexpression has been reported to promote cellular epithelial-mesenchymal transition and the tumor progression of ccRCC. The present study examined the effects of miR-218 on CIP2A expression in ccRCC cells. The results demonstrated that the expression level of miR-218 was lower in ccRCC tissues compared with that in adjacent non-tumor renal tissues. In addition, it was identified that miR-128 could directly bind to the 3'-untranslated region of CIP2A. Furthermore, a negative correlation between the expression levels of miR-218 and CIP2A was detected in ccRCC. Additionally, the downregulation of CIP2A or overexpression of miR-218 in ccRCC cells was revealed to inhibit cell proliferation and migration. In summary, these data suggest that miR-218 serves a role in the regulation of CIP2A and elucidate its consequences on tumor progression, tumor cell proliferation and migration. These results indicate that miR-218 may exhibit potential as a molecular target for the treatment of ccRCC.

MicroRNA-30a as a candidate underlying sex-specific differences in neonatal hyperoxic lung injury: implications for BPD

Premature male neonates are at a greater risk of developing bronchopulmonary dysplasia (BPD). The reasons underlying sexually dimorphic outcomes in premature neonates are not known. The role of miRNAs in mediating sex biases in BPD is understudied. Analysis of the pulmonary transcriptome revealed that a large percentage of angiogenesis-related differentially expressed genes are miR-30a targets. We tested the hypothesis that there is differential expression of miR-30a in vivo and in vitro in neonatal human pulmonary microvascular endothelial cells (HPMECs) upon exposure to hyperoxia. Neonatal male and female mice (C57BL/6) were exposed to hyperoxia [95% fraction of inspired oxygen (FiO2), postnatal day ( PND) 1-5] and euthanized on PND 7 and 21. HPMECs (18-24-wk gestation donors) were subjected to hyperoxia (95% O2 and 5% CO2) or normoxia (air and 5% CO2) up to 72 h. miR-30a expression was increased in both males and females in the acute phase ( PND 7) after hyperoxia exposure. However, at PND 21 (recovery phase), female mice showed significantly higher miR-30a expression in the lungs compared with male mice. Female HPMECs showed greater expression of miR-30a in vitro upon exposure to hyperoxia. Delta-like ligand 4 (Dll4) was an miR-30a target in HPMECs and showed sex-specific differential expression. miR-30a increased angiogenic sprouting in vitro in female HPMECs. Lastly, we show decreased expression of miR-30a and increased expression of DLL4 in human BPD lung samples compared with controls. These results support the hypothesis that miR-30a could, in part, contribute to the sex-specific molecular mechanisms in play that lead to the sexual dimorphism in BPD.

LncRNAs act as prognostic and diagnostic biomarkers in renal cell carcinoma: a systematic review and meta-analysis

We conducted a systematic review and meta-analysis to investigate the clinical values, including clinicopathology, prognosis, and diagnosis of different long non-coding RNAs (lncRNAs) in renal cell carcinoma (RCC). A total of 14 eligible studies, including 10 on clinicopathological features, 11 on prognosis, and 3 on diagnosis were identified. Results revealed that metastasis-associated lung adenocarcinoma transcript 1(MALAT1) expression was associated with tumor stage (odds ratio [OR], 3.46; 95% confidence interval [CI], 1.63-7.36; p=0.001). The high expression of MALAT1 could be considered a biomarker of the early detection of lymph node metastasis and predictor of poor survival in RCC patients, who likely manifested short overall survival (OS; hazard ratio [HR], 2.97; 95% CI, 1.68-5.28; p<0.001). For diagnostic value, the pooled result showed that lncRNA maintained a sensitivity of 0.89 and specificity of 0.91 in RCC diagnosis, The area under the curve of 0.94 (95% CI, 0.92-0.96) for lncRNA in RCC diagnosis also indicated a significant advantage over other biomarkers. Our systematic review and meta-analysis demonstrated that lncRNAs could be considered biomarkers to detect lymph node metastasis and distant metastasis in early stages. LncRNAs could function as potential prognostic markers in RCC. LncRNAs could also display high accuracy for RCC diagnosis.

MicroRNA-19a and microRNA-19b promote the malignancy of clear cell renal cell carcinoma through targeting the tumor suppressor RhoB

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell carcinoma, which shows high aggressiveness and lacks biomarkers. RhoB acts as a tumor suppressor that inhibits the progression of ccRCC. In the present study, we examined the effects of oncogenic microRNAs, miR-19a and miR-19b, on RhoB expression in ccRCC cells. The results showed that both miR-19a and miR-19b could directly target the 3′untranslated region (3’UTR) of RhoB, resulting in the reduced expression of RhoB. With RT-PCR analysis, we detected the increased expression of miR-19a and miR-19b in ccRCC tissues compared to adjacent non-tumor renal tissues. These data also demonstrated an exclusive negative correlation between miR-19a/19b and RhoB expression in ccRCC specimens and cell lines. In addition, the knockdown of RhoB or overexpression of miR-19a and miR-19b in ccRCC cells could promote cell proliferation, migration and invasion. These data demonstrate the direct roles of miR-19a and miR-19b on the repression of RhoB and its consequences on tumorigenesis, cancer cell proliferation and invasiveness. These results suggest the potential clinical impact of miR-19a and miR-19b as molecular targets for ccRCC.

miRNAs in Prediction of Prognosis in Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the most common type of urinary malignancy. Clear cell renal cell carcinoma (ccRCC) is the predominant RCC subtype, accounting for 70-80% of RCC. In recent years, miRNAs have been found to be closely associated with the outcome of the patients with ccRCC. In this review, we summarize recent advances in research exploring the role of miRNAs in predicting prognosis in patients with ccRCC.

MicroRNAs in cancer metastasis and angiogenesis

Cancer metastasis is a malignant process by which tumor cells migrate from their primary site of origin to other organs. It is the main cause of poor prognosis in cancer patients. Angiogenesis is the process of generating new blood capillaries from pre-existing vasculature. It plays a vital role in primary tumor growth and distant metastasis. MicroRNAs are small non-coding RNAs involved in regulating normal physiological processes as well as cancer pathogenesis. They suppress gene expression by specifically binding to the 3′-untranslated region (3′-UTR) of their target genes. They can thus act as oncogenes or tumor suppressors depending on the function of their target genes. MicroRNAs have shown great promise for use in anti-metastatic cancer therapy. In this article, we review the roles of various miRNAs in cancer angiogenesis and metastasis and highlight their potential for use in future therapies against metastatic cancer.

Androgen receptor increases hematogenous metastasis yet decreases lymphatic metastasis of renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a gender-biased tumor. Here we report that there is also a gender difference between pulmonary metastasis and lymph node metastasis showing that the androgen receptor (AR)-positive ccRCC may prefer to metastasize to lung rather than to lymph nodes. A higher AR expression increases ccRCC hematogenous metastasis yet decreases ccRCC lymphatic metastases. Mechanism dissection indicates that AR enhances miR-185-5p expression via binding to the androgen response elements located on the promoter of miR-185-5p, which suppresses VEGF-C expression via binding to its 3' UTR. In contrast, AR-enhanced miR-185-5p also promotes HIF2α/VEGF-A expression via binding to the promoter region of HIF2α. Together, these results provide a unique mechanism by which AR can either increase or decrease ccRCC metastasis at different sites and may help us to develop combined therapies using anti-AR and anti-VEGF-C compounds to better suppress ccRCC progression.The incidence of renal cell carcinoma is higher in males than in females due to the different androgen receptor signaling but the molecular mechanisms behind this gender bias are unclear. Here the authors show how androgen receptor expression influences the metastatic route through the regulation of miR-185 and VEGF isoforms.

The miR-30 family: Versatile players in breast cancer

The microRNA family, miR-30, plays diverse roles in regulating key aspects of neoplastic transformation, metastasis, and clinical outcomes in different types of tumors. Accumulating evidence proves that miR-30 family is pivotal in the breast cancer development by controlling critical signaling pathways and relevant oncogenes. Here, we review the roles of miR-30 family members in the tumorigenesis, metastasis, and drug resistance of breast cancer, and their application to predict the prognosis of breast cancer patients. We think miR-30 family members would be promising biomarkers for breast cancer and may bring a novel insight in molecular targeted therapy of breast cancer.

miR-30a radiosensitizes non-small cell lung cancer by targeting ATF1 that is involved in the phosphorylation of ATM

Increasing number of studies report that microRNAs play important roles in radiosensitization. miR-30a has been proved to perform many functions in the development and treatment of cancer, and it is downregulated in non-small cell lung cancer (NSCLC) tissues and cells. This study was conducted to understand if miR-30a plays a role in the radiosensitivity of NSCLC cells. Radiosensitivity was examed by colony survival assay and tumor volume changing in vitro and in vivo, respectively. Bioinformatic analysis and luciferase reporter assays were used to distinguish the candidate target of miR-30a. qRT-PCR and western blotting were carried out to detect the relative expression of mRNAs and proteins. Cell cycle and cell apoptosis were determined by flow cytometry. Our results illustrated miR-30a could increase the radiosensitivity of NSCLC, especially in A549 cell line. In vivo experiment also showed the potential radiosensitizing possibility of miR-30a. Further exploration validated that miR-30a was directly targeting activating transcription factor 1 (ATF1). In studying the ataxia-telangiectasia mutated (ATM) associated effects on cell radiosensitivity, we found that miR-30a could reduce radiation induced G2/M cell cycle arrest and may also affect radiation induced apoptosis. Together, our results demonstrated that miR-30a may modulate the radiosensitivity of NSCLC through reducing the function of ATF1 in phosphorylation of ATM and have potential therapeutic value.

MicroRNAs as prognostic molecular signatures in renal cell carcinoma: a systematic review and meta-analysis

This is a systematic review of studies investigating the prognostic value of different microRNAs (miRs) in renal cell carcinoma (RCC). Twenty-seven relevant studies were identified, with a total of 2578 subjects. We found that elevated expression of miR-21, miR-1260b, miR-210, miR-100, miR-125b, miR-221, miR-630, and miR-497 was associated with a poor prognosis in RCC patients. Conversely, decreased expression of miR-106b, miR-99a, miR-1826, miR-215, miR-217, miR-187, miR-129–3p, miR-23b, miR-27b, and miR-126 was associated with a worse prognosis. We performed meta-analyses on studies to address the prognostic value of miR-21, miR-126, miR-210, and miR-221. This revealed that elevated miR-21 expression was associated with shorter overall survival (OS; hazard ratio [HR], 2.29; 95% confidence interval [CI], 1.28–4.08), cancer specific survival (CSS; HR, 4.16; 95% CI, 2.49–6.95), and disease free survival (DFS; HR, 2.15; 95% CI, 1.16–3.98). The decreased expression of miR-126 was associated with shorter CSS (HR, 0.35; 95% CI, 0.15–0.85), OS (HR, 0.45; 95% CI, 0.30–0.69), and DFS (HR 0.30; 95% CI, 0.18–0.50). Our comprehensive systematic review reveals that miRs, especially miR-21 and miR-126, could be promising prognostic markers and useful therapeutic targets in RCC.

Overexpression of miR-30a in lung adenocarcinoma A549 cell line inhibits migration and invasion via targeting EYA2

MicroRNAs (miRNAs) are a class of small non-coding RNAs and closely related to the pathogenesis of cancers. Increasing evidence indicates that miR-30a plays a profound role during the development of cancers. However, the functions of miR-30a in non-small-cell lung cancer (NSCLC) are still ambiguous. Here we found that miR-30a was decreased in lung adenocarcinoma A549 cells and in tissue samples from 14 patients by qRT-PCR, and also found that overexpression of miR-30a in A549 cells inhibited migration and invasion but not cell proliferation and cell cycle progression by wound-healing assay, matrigel invasion assay, MTS-based cell proliferation assay, and flow cytometry-based cell cycle analysis, respectively. We further explored the potential mechanism of miR-30a-mediated gene regulation in lung adenocarcinoma cell lines. EYA2 is a predicted target of miR-30a, and it has been found that EYA2 expression is inhibited by miR-30a in breast cancer cells. We demonstrated that EYA2 is a direct target of miR-30a by using the dual-luciferase reporter assay in A549 cells and showed that EYA2 protein levels are inversely correlated with miR-30a expression in A549 and BEAS-2B cells. In addition, we also confirmed the rescue effects of EYA2 overexpression in A549 cells by cotransfection with EYA2 expression vector and miR-30a mimics. Taken together, our results demonstrate that overexpression of miR-30a in lung adenocarcinoma A549 cells can inhibit cell migration and invasion, which is partially attributed to the decrease of EYA2 expression. Our findings suggest that miR-30a may be used as a new potential target for the treatment of lung adenocarcinoma in the future.

MicroRNAs in the Pathogenesis of Renal Cell Carcinoma and Their Diagnostic and Prognostic Utility as Cancer Biomarkers

Purpose

To provide information about the role of microRNAs in the pathogenesis of renal cell carcinoma (RCC) and their diagnostic and prognostic utility as cancer biomarkers.

Methods

A literature search was performed in the PubMed and Web of Science databases using the keywords “renal cancer/renal cell carcinoma/kidney cancer” and “miR*/miRNA*/microRNA*”. Articles dealing with the role of miRNAs in the pathogenesis of RCC, diagnostic miRNAs and prognostic miRNAs were separated.

Results

MiRNAs act both as oncogenes and tumor suppressors. They regulate apoptosis, cell growth, migration, invasion, proliferation, colony formation and angiogenesis through target proteins involved in several signaling pathways, and they are involved in key pathogenetic mechanisms such as hypoxia (HIF/VHL dependent) and epithelial-to-mesenchymal transition. Differentially expressed miRNAs can discriminate either tumor tissue from healthy renal tissue or different RCC subtypes. Circulating miRNAs are promissing as diagnostic biomarkers of RCC. Information about urinary miRNAs associated with RCC is sparse. Detection of a relapse is another implication of diagnostic miRNAs. The expression profiles of several miRNAs correlate with the prognosis of RCC patients. Comparison between primary tumor tissue and metastasis may help identify high-risk primary tumors. Finally, response to target therapy can be estimated thanks to differences in miRNA expression in tissue and serum of therapy-resistant versus therapy-sensitive patients.

Conclusions

Our understanding of the role of microRNAs in RCC pathogenesis has been increasing dramatically. Identification and validation of their gene targets may have direct impact on developing microRNA-based anticancer therapy. Several microRNAs can serve as diagnostic and prognostic biomarkers.

MicroRNA-30a as a prognostic factor in urothelial carcinoma of bladder inhibits cellular malignancy by antagonising Notch1

OBJECTIVE

To explore the relation between microRNA-30a (miR-30a) and Notch1, and to evaluate the potential prognostic role of miR-30a in invasive urothelial carcinoma of the bladder (UCB).

PATIENTS AND METHODS

In all, 50 invasive UCB tissue specimens, along with the adjacent bladder tissue specimens were obtained, and the clinical parameters of the 50 patients were analysed. Bioinformatics analysis was performed and miR-30a was selected as a potential miRNA targeting Notch1, with a luciferase assay performed to verify the binding site between miR-30a and Notch1. Quantitative real-time reverse transcriptase-polymerase chain reaction was used to assess the RNA expressions of miR-30a and Notch1, while Western Blotting and immunohistochemical staining were used to assess the protein expression of Notch1. Finally, cell proliferation, cell cycle, cell migration and invasion assays were used to evaluate the cellular effects of miR-30a and Notch1 on the UCB cell lines T24 and 5637.

RESULTS

MiR-30a was downregulated in tumour tissues when compared with adjacent bladder tissues (P < 0.001), negatively correlating with Notch1 messenger RNA (R(2) 0.106, P = 0.021) in invasive UCB, and miR-30a expression further decreased in patients with shorter overall survival and disease-free survival (P = 0.039 and P = 0.037, respectively). The luciferase assay showed that miR-30a inhibited the Notch1 3'-untranslated region reporter activities in the T24 and 5637 cell lines (both P < 0.001). Both miR-30a and small interfering RNA Notch1 negatively regulated cell proliferation (P = 0.002 and P = 0.035 in T24; P = 0.029 and P = 0.037 in 5637 cell lines), activated cell cycle arrest (both P < 0.001 in T24; both P < 0.001 in 5637 cell lines), and prevented cellular migration (both P < 0.001 in T24; P = 0.003 and P < 0.001 in 5637 cell lines) and invasion (P = 0.009 and P = 0.006 in T24; P = 0.006 and P = 0.002 in 5637 cell lines) abilities. Ectopic Notch1 without the 3'untranslated region partially rescued the above-mentioned cellular effects of over-expressed miR-30a on T24 and 5637 cells.

CONCLUSIONS

MiR-30a lessens cellular malignancy by antagonising oncogene Notch1 and plays an effective prognostic role in invasive UCB.

Elevated S100A6 (Calcyclin) enhances tumorigenesis and suppresses CXCL14-induced apoptosis in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is often resistant to existing therapy. We found elevated S100A6 levels in ccRCC tissues, associated with higher grade pathological features and clinical stages in ccRCC patients. Knockdown of S100A6 inhibited cell proliferation in vitro and tumor growth in vivo. Gene expression profiling suggests a novel function of S100A6 in suppressing apoptosis, as well as a relationship between S100A6 and CXCL14, a pro-inflammatory chemokine. We suggest that the S100A6/CXCL14 signaling pathway is a potential therapeutic target in ccRCC.

The miRNA Transcriptome Directly Reflects the Physiological and Biochemical Differences between Red, White, and Intermediate Muscle Fiber Types

MicroRNAs (miRNAs) are small non-coding RNAs that can regulate their target genes at the post-transcriptional level. Skeletal muscle comprises different fiber types that can be broadly classified as red, intermediate, and white. Recently, a set of miRNAs was found expressed in a fiber type-specific manner in red and white fiber types. However, an in-depth analysis of the miRNA transcriptome differences between all three fiber types has not been undertaken. Herein, we collected 15 porcine skeletal muscles from different anatomical locations, which were then clearly divided into red, white, and intermediate fiber type based on the ratios of myosin heavy chain isoforms. We further illustrated that three muscles, which typically represented each muscle fiber type (i.e., red: peroneal longus (PL), intermediate: psoas major muscle (PMM), white: longissimus dorsi muscle (LDM)), have distinct metabolic patterns of mitochondrial and glycolytic enzyme levels. Furthermore, we constructed small RNA libraries for PL, PMM, and LDM using a deep sequencing approach. Results showed that the differentially expressed miRNAs were mainly enriched in PL and played a vital role in myogenesis and energy metabolism. Overall, this comprehensive analysis will contribute to a better understanding of the miRNA regulatory mechanism that achieves the phenotypic diversity of skeletal muscles.

miR149 rs71428439 polymorphism and risk of clear cell renal cell carcinoma: a case-control study

Clear cell renal cell carcinoma (CCRCC) is the most common subtype of renal cell cancer and accounts for 70 % of renal cell cancer. CCRCC remains an enigmatic tumor type, as the molecular genetic mechanisms are still unclear. MicroRNA (miR) 149 functions as a tumor suppressor and plays an important role in the carcinogenesis of renal cells. In this study, we enrolled 1,000 CCRCC patients and 1,000 cancer-free controls to evaluate the association of miR149 rs71428439 with the risk of CCRCC by a case-control study to determine the effects on CCRCC risk. miR149 rs71428439 was significantly associated with increased CCRCC risk (odds ratio (OR) for trend = 1.53, P for trend = 4.04 × 10(-11)), with ORs (95 % confidence intervals (CIs)) of 1.42 (1.17-1.72) associated with AG genotype and 2.27 (1.76-2.94) associated with GG genotype, compared with subjects with AA genotype. The expression levels of miR149 in cancer tissues were significantly lower than those in adjacent normal tissues (P = 0.005), and per G allele has significantly lower miR149 levels in both tumor tissues and adjacent normal tissues. Our data suggest that the GG genotypes of miR149 rs71428439 predispose their carriers to CCRCC, and miR149 rs71428439 may be a new biomarker for predicting the risk of CCRCC.

Differential expression of microRNAs in decidua-derived mesenchymal stem cells from patients with pre-eclampsia

BACKGROUND

Mesenchymal stem cells (MSCs) at maternal-fetal interface are considered to play an important role in the pathogenesis of pre-eclampsia (PE). microRNAs (miRNAs) also have an important influence on differentiation, maturation, and functions of MSCs. Our aim in this study was to determine the differential expression of miRNAs in decidua-derived MSCs (dMSCs) from severe PE and normal pregnancies.

RESULTS

miRNA expression profiles in dMSCs from five patients with severe PE and five healthy pregnant women were screened using microarray. Then, bioinformatic analysis of the microarray results was performed. Out of 179 differentially expressed miRNAs, 49 miRNAs had significant (p < 0.05) differential expression of ≥ 2.0-fold changes, including 21 up-regulated and 28 down-regulated. miRNA-Gene-network and miRNA-Gene ontology (GO) -network analyses were performed. Overall, 21 up-regulated and 15 down-regulated miRNAs showed high degrees in these analyses. Moreover, the significantly enriched signaling pathways and GOs were identified. The analyses revealed that pathways associated with cell proliferation, angiogenesis, and immune functions were highly regulated by the differentially expressed miRNAs, including Wnt signaling pathway, mitogen-activated protein kinase signaling pathway, transforming growth factor beta signaling pathway, T-cell receptor signaling pathway, and B cell receptor signaling pathway. Four miRNA predicted target genes, vascular endothelial growth factor A (VEGFA), indoleamine 2,3-dioxygenase, suppression of cytokine signaling 3, and serine/threonine protein phosphatase 2A 55 kDa regulatory subunit B α isoform (PPP2R2A) were all decreased in dMSCs from patients with PE. Furthermore, the physiological roles of miR-16 and miR-136 in the down-regulation of VEGFA and PPP2R2A, respectively, were confirmed through reporter assays.

CONCLUSIONS

These findings suggest that miRNAs in dMSCs may be important regulatory molecules in the development of PE.

Endothelial Delta-like 4 (DLL4) promotes renal cell carcinoma hematogenous metastasis

The Notch ligand Delta-like 4 (DLL4) plays an important role in tumor angiogenesis, which is required for tumor invasion and metastasis. Here we showed that DLL4 was elevated in endothelium and Notch signaling was activated in renal cell carcinoma (RCC). Exogenous DLL4 induced RCC cell migration and invasion by activating intercellular Notch signaling. Importantly, the DLL4/Notch/Hey1/MMP9 cascades connecting the endothelium to the cancer cells in metastasis were identified. Knockdown of Hey1 decreased expression of MMP9 and attenuated tumor invasion. The clinical investigation on 120 cases of RCC specimens indicated that expressions of Hey1 and MMP9 correlated with DLL4 density. Moreover, univariate and multivariate analyses showed that tumor hematogenous metastasis not only was depended on microvessel density but was also associated with tumor size and DLL4 density. During 4-year surveillance, high-level of DLL4 density was associated with a higher probability of developing metastasis and being sensitive to target therapies. Our data suggest that RCC progression is caused in part by activated DLL4/Notch signaling, interaction of endothelium and cells, which can be therapeutically targeted.

Exploring the miRNA-mRNA regulatory network in clear cell renal cell carcinomas by next-generation sequencing expression profiles

Altered microRNA (miRNA) expression is a hallmark of many cancer types. The combined analysis of miRNA and messenger RNA (mRNA) expression profiles is crucial to identifying links between deregulated miRNAs and oncogenic pathways. Therefore, we investigated the small non-coding (snc) transcriptomes of nine clear cell renal cell carcinomas (ccRCCs) and adjacent normal tissues for alterations in miRNA expression using a publicly available small RNA-Sequencing (sRNA-Seq) raw-dataset. We constructed a network of deregulated miRNAs and a set of differentially expressed genes publicly available from an independent study to in silico determine miRNAs that contribute to clear cell renal cell carcinogenesis. From a total of 1,672 sncRNAs, 61 were differentially expressed across all ccRCC tissue samples. Several with known implications in ccRCC development, like the upregulated miR-21-5p, miR-142-5p, as well as the downregulated miR-106a-5p, miR-135a-5p, or miR-206. Additionally, novel promising candidates like miR-3065, which i.a. targets NRP2 and FLT1, were detected in this study. Interaction network analysis revealed pivotal roles for miR-106a-5p, whose loss might contribute to the upregulation of 49 target mRNAs, miR-135a-5p (32 targets), miR-206 (28 targets), miR-363-3p (22 targets), and miR-216b (13 targets). Among these targets are the angiogenesis, metastasis, and motility promoting oncogenes c-MET, VEGFA, NRP2, and FLT1, the latter two coding for VEGFA receptors.