Aberrantly expressed microRNAs in bladder cancer and renal cell carcinoma

Urinary miRNAs Predict Metastasis in Patients With Clinically Localized Clear Cell Renal Cell Carcinoma Treated With Nephrectomy

PURPOSE

Patients with clear cell renal cell carcinoma (ccRCC) might develop metastasis after surgery with curative intent. We aimed to characterize the expression levels of microRNAs in the urine (UmiRNAs) of patients before and after nephrectomy to determine the impact of UmiRNAs expression in the emergence of metastases.

METHODS

We prospectively collected pre- and post-nephrectomy urine samples from 117 patients with clinically localized and locally advanced ccRCC. UmiRNAs were extracted, purified, and measured using RT-PCR. Relative quantifications (RQ) of 137 UmiRNAs were calculated through 2-∆∆ method. The post-surgery/pre-surgery RQs ratio represented the magnitude of the expression levels of the UmiRNAs. The association of UmiRNA expression and the development of distant metastases was tested with Cox regression model.

RESULTS

Five UmiRNAs (miR-191-5p, miR-324-3p, miR-186-5p, miR-93-5p, miR-30b-5p) levels were upregulated before nephrectomy (p < .05). This conferred a 2- to 4-fold increased risk of metastasis, with miR-191-5p showing the most significant association with this endpoint (HR = 4.16, 95% CI = 1.38-12.58, p = .011). In a multivariate model stratified with stage and Fuhrman grade, we found that miR-191-5p, miR-324-3p, and miR-186-5p exhibited a strong association with metastasis development in patients with pathological T3 (pT3) tumors. Enrichment analysis with the most differentially expressed UmiRNAs showed that these UmiRNAs targeted genes that regulate cell survival and proliferation.

CONCLUSION

Our study indicated UmiR-191-5p, UmiR-324-3p, and UmiR-186-5p are potential markers to predict the development of metastasis, particularly in pT3 patients.

PATIENT SUMMARY

We compared changes of UmiRNAs expression detected pre- and postnephrectomy of patients with ccRCC. Our findings suggest that UmiRNA expression likely reflects tumor-specific changes that can be promising to predict the metastasis development, particularly in patients with non-metastatic locally advanced ccRCC. If confirmed, these findings may be useful for surveillance protocols for adjuvant therapy protocols.

Candidate Oligo Therapeutic Target, miR-330-3p, Induces Tamoxifen Resistance in Estrogen Receptor-Positive Breast Cancer Cells via HDAC4

Tamoxifen is a drug used for treating breast cancer (BC), especially for individuals diagnosed with estrogen receptor-positive (ER+) BC. Its prolonged use could reduce the risk of recurrence and significantly lengthen the survival rate of BC patients. However, an increasing number of patients developed resistance to tamoxifen treatment, which reduced therapeutic efficiency and caused substandard prognosis. Therefore, the exploration of the molecular processes involved in tamoxifen resistance (TR) is urgently required. This investigation aimed to elucidate the relationship of microRNA-330 (miR-330-3p) with the TR of BC. There is little information on miR-330-3p's link with drug-resistant BC, although it is well known to regulate cell proliferation and apoptosis. Primarily, miR-330-3p expression in parental BC (MCF7/T47D), TR (MCF7-TR), and T47D/TR cell lines was detected by qRT-PCR. Then, the impact of miR-330-3p on the TR of BC cells was assessed by a cell proliferation assay. Lastly, dual-luciferase reporter, qRT-PCR, and western blot assessments were carried out to identify histone deacetylase 4 (HDAC4) as the potential miR-330-3p target gene. The data indicated that miRNA-330 was overexpressed in TR ER+ BC cells and its overexpression could induce TR. Furthermore, miRNA-330 could also reduce the expression of HDAC4, which is closely linked to TR, and overexpression of HDAC4 could reverse miRNA-330-induced drug resistance. In summary, miR-330-3p could induce TR of ER+ BC cells by downregulating HDAC4 expression, which might be a novel marker of TR and a possible treatment target against BC patients who are tamoxifen-resistant.

LncRNA FGD5-AS1 potentiates autophagy-associated doxorubicin resistance by regulating the miR-154-5p/WNT5A axis in osteosarcoma

Osteosarcoma is prevalent in children and adolescent. The oncogenic function of long-chain noncoding RNA (lncRNA) FGD5 antisense RNA 1 (FGD5-AS1) has been reported. However, the function of FGD5-AS1 in doxorubicin-resistance in osteosarcoma remains to be illucidated. Quantitative real-time PCR (qRT-PCR) and western blot analysis (WB) were used to measure the expression of FGD5-AS1, miR-154-5p, WNT5A and autophagy proteins. MTT assay was used to assess cell viability and transwell assay was performed to evaluate migration. A nude mouse xenograft model was developed to verify the function of FGD5-AS1 in vivo. FGD5-AS1 was upregulated in doxorubicin-resistant (DXR) osteosarcoma cells. Knockdown of FGD5-AS1 suppressed osteosarcoma cell proliferation, migration, and autophagy. FGD5-AS1 upregulated WNT5A expression via sponging miR-154-5p. Furthermore, FGD5-AS1 enhanced osteosarcoma cell chemotherapy resistance through upregulation of WNT5A by inhibiting miR-154-5p. Suppression of FGD5-AS1 significantly suppressed tumor growth in nude mice. FGD5-AS1 may promote chemoresistance through WNT5A-induced autophagy by sponging miR-154-5p in osteosarcoma cells.

miR-200a-3p facilitates bladder cancer cell proliferation by targeting the A20 gene

Background

MicroRNAs (miRs) are endogenous, single-stranded, noncoding RNAs that are involved in various physiological processes, and the development and the progression of various types of cancer. Specifically, the role of miR-200a-3p has been implicated in various types of cancer in contributing to a diverse array of cancer types has been previously reported. The present study aimed to investigate the expression levels of miR-200a-3p in human bladder cancer, as well as its potential role in disease pathogenesis.

Methods

Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect the expression of has-mir-200a-3p and tumor necrosis factor α (TNF-α) induced protein 3 (A20) in tumor tissues and cell lines. Dual-luciferase reporter assay and combination with the expression intervention of hsa-mir-200a-3p and A20 in bladder cancer cell lines to clarify the binding relationship between hsa-mir-200a-3p and A20.After the expression intervention of hsa-mir-200a-3p and A20 in bladder cancer cells, the changes of cell proliferation, cell apoptosis, cell cycle, wound-healing ability and migration ability were detected by CCK8, flow cytometry, wound-healing and Transwell methods. Xenograft transplantation model was performed subcutaneously in nude mice by implantation of J82 and T24 cells, and then the bladder cancer growth curve was calculated from mice exposed to has-mir-200a-3p minic or minic-NC.

Results

Bladder cancer tissues demonstrated significantly upregulated miR-200a-3p expression levels. Moreover, increased miR-200a-3p expression was significantly associated with distant metastasis and advanced stage. In addition, compared with the miR-control (Ctr) group, miR-200a-3p overexpression promoted bladder cancer cell proliferation, migration, invasion, cell cycle, and release of inflammatory cytokines, but inhibited cell apoptosis. Mechanistically, A20 was identified as a target gene of miR-200a-3p in bladder cancer cell lines. Moreover, compared with the miR-Ctr group, the miR-200a-3p overexpression group exhibited significantly promoted tumor growth in vivo, and A20 overexpression blocked the promoting effect of miR-200a-3p on bladder cancer.

Conclusions

The results of the present study indicated that miR-200a-3p might serve act as an oncogene in human bladder cancer by targeting a novel the gene A20 gene; therefore, miR-200a-3p and A20 might serve could serve as novel therapeutic targets for bladder cancer.

LncRNA HAND2-AS1 exerts anti-oncogenic effects on bladder cancer via restoration of RARB as a sponge of microRNA-146

Background

Growing evidence has shown that long noncoding RNA: microRNA: mRNA is implicated in tumor initiation, development, and progression. Long noncoding RNA HAND2-AS1 exhibits anti-cancer effects in diverse cancers. However, the knowledge of HAND-AS1 in bladder cancer development remains unknown.

Methods

LncRNA and miRNA microarray was conducted to explore different expressed RNA in primary bladder cancer specimens. RNA-RNA interaction prediction tools miRcode (http://www.mircode.org/), DIANA-lncBase v2 (https://carolina.imis.athena-innovation.gr/diana_tools/web/index.php?r=lncbasev2%2Findex-experimental), DIANA-TarBase v.8 (https://carolina.imis.athena-innovation.gr/diana_tools/web/index.php?r=tarbasev8%2Findex) and miRDB (http://www.mirdb.org/) were employed to predict the interactions between RNA. Bladder cancer cell lines were used to perform cell proliferation and apoptosis assays. Western blot and quantitative Real-time Polymerase Chain Reaction were used to determine the expression of protein and RNA separately. Dual-luciferase assay was conducted to determine the activity of three prime untranslated region of retinoic acid receptor beta (RARB). Furthermore, 5637 human bladder cancer mouse models were established to investigate the interactions of lncRNA: miRNA: mRNA in vivo.

Results

Based on the RT2 lncRNA PCR Arrays analysis, we validated HAND2-AS1 declined in bladder cancer and negatively correlated with the depth of invasion and grades. The overexpression of HAND2-AS1 in human bladder cancer cells 5637 and RT4 hampered cell proliferation by provoking Caspase 3-triggered cell apoptosis. Besides, one of the HAND2-AS1 sponges, miR-146, elevated in bladder cancer and targeted the tumor suppressor, retinoic acid receptor beta (RARB). We further demonstrated that the HAND2-AS1: miR-146: RARB complex promoted Caspase 3-mediated apoptosis by suppressing COX-2 expression. Finally, the results gained in mouse xenografts suggested that HAND2-AS1 diminished miR-146 expression, thereby reversing the suppression of miR-146 on RARB-mediated apoptosis and contributing to bladder cancer regression.

Conclusion

The present study sheds light on the fact that lncRNA HAND2-AS1 exerted as a tumor suppressor by releasing RARB from miR-146, leading to tumor proliferation and invasion inhibition. The findings expanded HAND2-AS-mediated regulatory networks' knowledge and provided novel insights to improve the RARB-targeted regimens against bladder cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02063-y.

MicroRNAs MiR-15a and MiR-26a cooperatively regulate O-GlcNAc-transferase to control proliferation in clear cell renal cell carcinoma

BACKGROUND

MicroRNAs (miRNAs), a group of non-coding post-transcriptional regulators of gene expression, are dysregulated in clear cell renal cell carcinoma (ccRCC) and play an important role in carcinogenesis. Our prior work identified a subset of miRNAs in pT1 ccRCC tumors associated with progression to metastatic disease.

OBJECTIVE

To investigate the impact of two of these dysregulated miRNA, miR-15a-5p and -26a-5p, in an effort to elucidate the mechanisms underpinning aggressive forms of stage I ccRCC.

METHODS

The ccRCC cell line 786-O was transfected with pre-miRs-15a-5p and -26a-5p to rescue expression. Cell proliferation was measured via MT Cell Viability Assay. O-GlcNAc-transferase (OGT), a known protein in ccRCC proliferation, was identified by bioinformatics analysis as a target of both miRNA and validated via luciferase reporter assay to confirm binding of each miR to the 3' untranslated region (UTR). OGT protein expression was evaluated via western blotting.

RESULTS

Luciferase assay confirmed specificity of miR-15a-5p and -26a-5p for the OGT UTR. Western blot analysis for OGT showed reduced expression following co-transfection of both miRNAs compared to negative control or individual transfection. Co-transfection of these miRNAs greatly reduced proliferation when compared to negative control or the individual transfections.

CONCLUSION

Our results indicate that the dysregulation of miR-15a-5p and -26a-5p contribute cooperatively to the proliferation of ccRCC through their regulation of OGT. These results give insight into the pathogenesis of aggressive early stage ccRCC and suggest potential therapeutic targets for future research.

Identification of a novel immune-related microRNA prognostic model in clear cell renal cell carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) is a type of kidney cancer, and one of the most common malignant tumors. Many studies have shown that certain microRNAs (miRNAs) play an important role in the occurrence and development of ccRCC. Nevertheless, the prognosis of ccRCC patients is very rarely based on these “immuno-miRs”. Our aim was thus to determine the relationship between immune-related miRNA signatures and ccRCC.

Methods

We downloaded the miRNA expression data from 521 KIRC and 71 normal tissues in The Cancer Genome Atlas (TCGA). We used “limma” package and univariate Cox regression analysis to identify differentially expressed miRNAs (DEMs) that related to overall survival (OS). We applied lasso and multivariate Cox regression analyses to construct a prognostic model based on immuno-miRs. We evaluated the performance of model by using the Kaplan-Meier method. Furthermore, Cox regression analysis was used to determine independent prognostic signatures in ccRCC.

Results

A total of 59 significant immuno-miRs were identified. We use univariate Cox regression analysis to acquire 18 immune-related miRNAs which were markedly related to OS of ccRCC patients in the training set. We then constructed the 9-immune-related-miRNA prognostic model (miR-21, miR-342, miR-149, miR-130b, miR-223, miR-365a, miR-9-1, and miR-146b) by using lasso and multivariate Cox regression. Further analysis suggested that the immune-related prognostic model could be an independent prognostic indicator for patients with ccRCC. The prognostic performance of the 9-immune-related-miRNA prognostic model was further validated successfully in the testing set.

Conclusions

We established a novel immune-based prognostic model of ccRCC based on potential prognostic immune-related miRNAs. Our results indicated that the 9-miRNA signature could be a practical and reliable prognostic tool for ccRCC.

MicroRNA profile in stage I clear cell renal cell carcinoma predicts progression to metastatic disease

OBJECTIVE

This study sought to identify microRNA (miRNA) profiles of small, pathologically confirmed stage 1 clear cell renal cell carcinoma (ccRCC) tumors that are associated with progression to metachronous metastatic disease.

MATERIALS AND METHODS

Fifty-five pathologic stage 1 ccRCC tumors ≤5cm, from 2 institutions, were examined in a miRNA screening, followed by a validation study. For the screening phase 752 miRNA were evaluated on each sample to identify those with differential expression between tumors that subsequently did (n = 10) or did not (n = 10) progress to metastatic disease. For the validation, 35 additional samples (20 nonprogressors and 15 with distant progression) were utilized to investigate 20 miRNA to determine if a miRNA panel could differentiate aggressive tumors: associations of miRNA expression with cancer specific survival was also investigated.

RESULTS

In the screening analysis, 35 miRNA were differentially expressed (P < 0.05, FDR < 0.1) between the groups. In the validation, 11 miRNA were confirmed to have differential expression. The miRNA -10a-5p, -23b-3p, and -26a-5p differentiated nonprogressive and distant progressive disease with a sensitivity of 73.3% and a specificity of 85% (AUC=0.893). In addition, levels of miR-30a-3p and -145-5p were identified as independent prognostic factors of cancer specific survival.

CONCLUSIONS

This investigation identified miRNA biomarkers that may differentiate between non-progressive ccRCC tumors and those that progress to metastatic disease in this group of stage I tumors. The miRNA profiles determined in this study have the potential to identify patients with small renal masses who are likely to have progressive ccRCC. Such information may be valuable to incorporate into predictive models.

The circular RNA hsa-circ-0072309 plays anti-tumour roles by sponging miR-100 through the deactivation of PI3K/AKT and mTOR pathways in the renal carcinoma cell lines

Aims: To explore the roles and regulatory mechanisms of the circular RNA (circRNA)-hsa-circ-0072309 in CAKI-1 and ACHN cells. Methods: CAKI-1 and ACHN cells were transfected with hsa-circ-0072309 overproduction vector (circRNA) and microRNA-100 (miR-100) mimic or the corresponding controls. Cell viability was detected with the CCK-8. The protein expression levels of p53, c-Myc, cleaved-caspase-3/9, matrix metalloproteinase (MMP)-2/9, vimentin, AKT, PI3K and mTOR were individually determined through western blot. qRT-PCR was used to examine the expressions of hsa-circ-0072309 and miR-100. The apoptotic rate and the migration or invasion rates were separately determined by the annexin v-FITC/PI with a flow cytometer and modified two-chamber migration assay or millicell hanging cell culture. Results: The hsa-circ-0072309 was poorly expressed in tumor tissue. Abundant hsa-circ-0072309 induced the inhibitions of cell proliferation, migration and invasion, as well as the PI3K/AKT and the mTOR cascades but enhancement of apoptosis. circRNA stimulated the down-regulation of miR-100, which was low-expressed in tumour tissue and whose overproduction abolished the impacts of circRNA on these elements mentioned above. Conclusion: The hsa-circ-0072309 played anti-tumour roles by targeting miR-100 by blocking the PI3K/AKT and mTOR cascades in the CAKI-1 and ACHN cell lines.

Connecting the dots between different networks: miRNAs associated with bladder cancer risk and progression

BACKGROUND

Bladder cancer (BC) is a common urothelial malignancy, characterized by a high recurrence rate. The biology of bladder cancer is complex and needs to be deciphered. The latest evidence reveals the critical role of the non-coding RNAs, particularly microRNAs (miRNAs), as vital regulatory elements in cancer.

METHOD

We performed a miRNAs microarray using paired tissues (tumor and adjacent normal bladder tissue), followed by the validation with qRT-PCR of five selected transcripts. Additional next-generation sequencing investigation established the interconnection among the altered miRNAs and mutated genes. Based on the overlapping between TCGA data and data obtained in the study, we focused on the systematic identification of altered miRNAs and genes mutated involved in bladder cancer tumorigenesis and progression.

RESULTS

By overlapping the miRNAs expression data, the two patient cohorts, we identified 18 miRNAs downregulated and, 187 miRNAs upregulated. qRT-PCR validation was completed using a selected panel of two downregulated (miR-139-5p and miR-143-5p) and three up-regulated miRNAs (miR-141b, miR-200 s or miR-205). Altered miRNAs patterns are interrelated to bladder tumorigenesis, allowing them to be used for the development of novel diagnostic and prognostic biomarkers. Three EMT-related upregulated miRNAs have an essential role in the molecular mechanisms, specifically key processes underlying tumorigenesis, invasion and metastasis. Using the Ampliseq Cancer Panel kit and Ion Torrent PGM Next-Generation Sequencing an increased mutation rate for TP53, FGFR3, KDR, PIK3CA and ATM were observed, but the mutational status for only TP53 was correlated to the survival rate. The miRNAs pattern, along with the gene mutation pattern attained, can assist for better patient diagnosis.

CONCLUSION

This study thereby incorporates miRNAs as critical players in bladder cancer prognosis, where their altered gene expression profiles have a critical biological function in relationship with tumor molecular phenotype. The miRNA-mRNA regulatory networks identified in BC are ripe for exploitation as biomarkers or targeted therapeutic strategies.

Prognostic significance of laterality in renal cell carcinoma: A population-based study from the surveillance, epidemiology, and end results (SEER) database

Background

Various prognostic characteristics have been established in the renal cell carcinoma (RCC). However, the impact of tumor laterality is unknown. The objective of the current study was to explore the predictive and prognostic impact of tumor laterality of RCC after surgery.

Methods

This investigation was a population‐based retrospective cohort study of patients with RCC from the surveillance, epidemiology, and end results (SEER) database in the USA. All patients received surgical treatment between January 2010 and December 2014. Cancer‐specific survival (CSS) measured from the time of surgery.

Results

This study identified 41 138 surgically treated RCC patients: Of these patients, 50.6% had right‐sided RCC, 59.5% were younger than 65 years of age, 63.8% were male, and 81.0% were Caucasian. The stage distribution was 67.0% (I), 9.5% (II), 17.1% (III), and 6.4% (IV). Patients with right‐sided RCC were more likely to have favorable clinicopathological features compared with patients with left‐sided RCC. In adjusted analyses, patients with right‐sided RCC showed significantly better CSS than those with left‐sided RCC within different subgroups including tumor size ≥10 cm (P = .004), age <65 years (P = .002), male gender (P = .001), Caucasian race (P = .001), clear cell carcinoma type (P = .024), and radical nephrectomy (P = 0.008). Moreover, in the subgroup of tumor size ≥10 cm, right‐sided cancer was an independent predictor of CSS (P = .022).

Conclusion

Right‐sided RCC is associated with more early‐stage, low‐grade disease and shows better CSS than left‐sided RCC. Moreover, laterality remained as an independent prognostic factor for cancer‐specific survival in subgroup of tumor size ≥10 cm RCC.

miR-22 Regulates Invasion, Gene Expression and Predicts Overall Survival in Patients with Clear Cell Renal Cell Carcinoma

Background:

Clear cell renal cell carcinoma (ccRCC) is molecularly diverse and distinct molecular subtypes show different clinical outcomes. MicroRNAs (miRNAs) are essential components of gene regulatory networks and play a crucial role in progression of many cancer types including ccRCC.

Objective:

Identify prognostic miRNAs and determine the role of miR-22 in ccRCC.

Methods:

Hierarchical clustering was done in R using gene expression profiles of over 450 ccRCC cases in The Cancer Genome Atlas (TCGA). Kaplan-Meier analysis was performed to identify prognostic miRNAs in the TCGA dataset. RNA-Seq was performed to identify miR-22 target genes in primary ccRCC cells and Matrigel invasion assay was performed to assess the effects of miR-22 overexpression on cell invasion.

Results:

Hierarchical clustering analysis using 2,621 prognostic genes previously identified by our group demonstrated that ccRCC patients with longer overall survival expressed lower levels of genes promoting proliferation or immune responses, while better maintaining gene expression associated with cortical differentiation and cell adhesion. Targets of 26 miRNAs were significantly enriched in the 2,621 prognostic genes and these miRNAs were prognostic by themselves. MiR-22 was associated with poor overall survival in the TCGA dataset. Overexpression of miR-22 promoted invasion of primary ccRCC cells in vitro and modulated transcriptional programs implicated in cancer progression including DNA repair, cell proliferation and invasion.

Conclusions:

Our results suggest that ccRCCs with differential clinical outcomes have distinct transcriptomes for which miRNAs could serve as master regulators. MiR-22, as a master regulator, promotes ccRCC progression at least in part by enhancing cell invasion.

Aberrantly expressed PLOD1 promotes cancer aggressiveness in bladder cancer: a potential prognostic marker and therapeutic target

Bladder cancer (BC) is the ninth most malignant tumor worldwide. Some BC patients will develop muscle‐invasive BC (MIBC), which has a 5‐year survival rate of approximately 60% due to metastasis. As such, there is an urgent need for novel therapeutic and diagnostic targets for MIBC. Analysis of novel antitumor microRNA (miRNA)‐mediated cancer networks is an effective strategy for exploring therapeutic targets and prognostic markers in cancers. Our previous miRNA analysis revealed that miR‐140‐5p acts as an antitumor miRNA in BC cells. Here, we investigated miR‐140‐5p regulation of BC molecular pathogenesis. Procollagen‐lysine, 2‐oxoglutarate 5‐dioxygenase 1 (PLOD1) was found to be directly regulated by miR‐140‐5p, and aberrant expression of PLOD1 was observed in BC clinical specimens. High PLOD1 expression was significantly associated with a poor prognosis (disease‐free survival: P = 0.0204; overall survival: P = 0.000174). Multivariate analysis showed PLOD1 expression to be an independent prognostic factor in BC patients (hazard ratio = 1.51, P = 0.0099). Furthermore, downregulation of PLOD1 by siRNAs and a specific inhibitor significantly decreased BC cell aggressiveness. Aberrant expression of PLOD1 was closely associated with BC pathogenesis. In summary, the present study showed that PLOD1 may be a potential prognostic marker and therapeutic target for BC.

MicroRNA heterogeneity in melanoma progression

The altered expression of miRNAs has been linked with neocarcinogenesis or the development of human malignancies including melanoma. Of significance, multiple clinical studies have documented that distinct sets of microRNAs (miRNAs) could be utilized as prognostic biomarkers for cancer development or predict the outcomes of treatment responses. To that end, an in-depth validation of such differentially expressed miRNAs is necessary in diverse settings of cancer patients in order to devise novel approaches to control tumor growth and/or enhance the efficacy of clinically-relevant therapeutic options. Moreover, considering the heterogeneity and sophisticated regulation of miRNAs, the precise delineation of their cellular targets could also be explored to design personalized medicine. Given the significance of miRNAs in regulating several key cellular processes of tumor cells including cell cycle progression and apoptosis, we review the findings of such miRNAs implicated in melanoma tumorigenesis. Understanding the novel mechanistic insights of such miRNAs will be useful for developing diagnostic or prognostic biomarkers or devising future therapeutic intervention for malignant melanoma.

The landscape of miRNA-related ceRNA networks for marking different renal cell carcinoma subtypes

We know that different types of cancers usually have different responses to the same treatment. Therefore, it is important to understand the similarities and differences across subtypes of cancers, so as to provide a basis for the individualized treatments. Until now, no comprehensive investigation on competing endogenous RNAs (ceRNAs) has been reported for the three main subtypes of renal cell carcinoma (RCC), so the regulation characteristics of ceRNAs in three subtypes are not well revealed. This paper firstly describes a comparative analysis of ceRNA-ceRNA interaction networks for all the three subtypes of RCC based on differential microRNAs (miRNAs). We comprehensively summarized all miRNA and messenger RNAdata of RCC from 126 matched tumor-normal tissues in The Cancer Genome Atlas, systematically analyzed a total of more than 80 000 ceRNA interactions and highlighted the common and specific properties among them, aiming to identify critical genes to classify them for providing supplementary help in the precise diagnosis of RCC. From three aspects, including common or specific ceRNAs, upregulated or downregulated and classifications across the three subtypes, we highlighted the common and specific properties for the three subtypes and also explored the classification of RCC by combining the specific ceRNAs with differential regulations. Moreover, for the most major subtype of clear cell renal cell carcinoma (KIRC), three critical genes were screened out from KIRC ceRNA network and further demonstrated to be the potential biomarkers of KIRC by performing biological experiments at the transcriptional level.

Identification and validation of a four-miRNA (miRNA-21-5p, miRNA-9-5p, miR-149-5p, and miRNA-30b-5p) prognosis signature in clear cell renal cell carcinoma

Purpose

Clear cell renal cell carcinoma (ccRCC) is one of the most common cancers with high mortality worldwide. However, biomarkers for predicting prognosis in ccRCC are limited. In this study, we attempted to identify potential prognostic biomarkers of ccRCC.

Methods

Clinical information and the preprocessed ccRCC mature miRNA expression profiles in The Cancer Genome Atlas database were downloaded from UCSC Xena. The miRNAs differentially expressed between ccRCCs and matched normal tissues were analyzed using the “limma” package. A miRNA-based signature was constructed using the multivariate Cox regression model with prognosis index (PI) formula. Patients with ccRCC were divided into low-risk and high-risk subgroups according to median PI. The survival times were compared between the two groups using Kaplan–Meier analysis with log-rank test. The training set was used to construct a miRNA-based signature for predicting prognosis. The test set was used to verify the signature. Target gene prediction and functional enrichment analysis of the four miRNAs were performed using miRNet.

Results

We identified four miRNAs, miRNA-21-5p, miRNA-9-5p, miR-149-5p, and miRNA-30b-5p, as independent prognostic indicators. Next, we used these four miRNAs to construct a four-miRNA PI for each patient. Results revealed that patients in the high-risk group (n=119) had significantly shorter survival time than those in the low-risk group (n=118) (high-risk/low-risk group log-rank P=0.000). This four-miRNA signature is an independent prognostic factor compared with routine clinicopathological features in the test set. These miRNAs targeted 1,634 genes, and a miRNA-target gene network was constructed using miRNet. The target genes of these four miRNAs were involved in various pathways related to cancer.

Conclusion

Our observations suggest that the four-miRNA signature correlated with the survival of patients with ccRCC and can be used as a prognostic biomarker of ccRCC.

MicroRNA‑663 inhibits the proliferation and invasion of clear cell renal cell carcinoma cells by directly targeting PAK4

Accumulating evidence has demonstrated that microRNAs (miRNAs) are key gene regulators and are abnormally expressed in clear cell renal cell carcinoma (ccRCC). The dysregulation of miRNAs has been implicated in the initiation and progression of ccRCC. Therefore, identification of ccRCC‑associated miRNAs may facilitate the determination of promising therapeutic targets for anti‑cancer treatment. In the present study, miRNA‑663 (miR‑663) expression was downregulated in ccRCC tissues and cell lines. Functional experiments suggested that restoration of miR‑663 expression inhibited the proliferation and invasion of ccRCC cells. In addition, p21 activated kinase 4 (PAK4) was validated as a direct target of miR‑663 in ccRCC cells. PAK4 was upregulated in ccRCC tissues, and the expression level of PAK4 was inversely correlated with the miR‑663 expression level. PAK4 restoration partially attenuated the suppressive roles of miR‑663 overexpression on the proliferation and invasion of ccRCC cells. The present results provide novel insight into the mechanism underlying the occurrence and development of ccRCC, suggesting that the miR‑663/PAK4 axis may be a novel therapeutic target for treatment of patients with ccRCC.

Long noncoding RNA TUG1 promotes renal cell carcinoma cell proliferation, migration and invasion by downregulating microRNA‑196a

Long noncoding RNA taurine upregulated gene 1 (lncRNA TUG1) and microRNA‑196a (miR‑196a) have been reported to serve important roles in the development of renal cell carcinoma (RCC). However, their potential mechanisms have not been completely elucidated. The aim of the present study was to clarify the biological functions of lncRNA‑TUG1 and miR‑196a, in addition to investigating the interaction between lncRNA‑TUG1 and microRNA‑196a, providing a novel insight into RCC tumorigenesis. The present study comprised two parts. In the first part, lncRNA‑TUG1 was confirmed as an oncogene, via reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) analysis, MTT assay, flow cytometry analysis, and migration and invasion assays. In the second part, the association between lncRNA‑TUG1 and miR‑196a, and the molecular mechanism, was illustrated via RT‑qPCR analysis, MTT assay, dual luciferase reporter assay and western blotting. The results of the present study demonstrated that lncRNA‑TUG1 was able to promote RCC cell proliferation, migration and invasion in vitro by suppressing miR‑196a. Additionally, lncRNA‑TUG1 achieved its biological functions by regulating the expression levels of RAC‑α serine/threonine‑protein kinase, mitogen‑activated protein kinase and extracellular signal‑regulated kinase via inhibition of miR‑196a. In conclusion, the present findings proposed a novel potential therapeutic target, the lncRNA‑TUG1‑miR‑196a axis, which may be applicable to the treatment of RCC.

Regulation of antitumor miR-144-5p targets oncogenes: Direct regulation of syndecan-3 and its clinical significance

In the human genome, miR-451a, miR-144-5p (passenger strand), and miR-144-3p (guide strand) reside in clustered microRNA (miRNA) sequences located within the 17q11.2 region. Low expression of these miRNAs is significantly associated with poor prognosis of patients with renal cell carcinoma (RCC) (miR-451a: P = .00305; miR-144-5p: P = .00128; miR-144-3p: P = 9.45 × 10-5 ). We previously reported that miR-451a acted as an antitumor miRNA in RCC cells. Involvement of the passenger strand of the miR-144 duplex in the pathogenesis of RCC is not well understood. Functional assays showed that miR-144-5p and miR-144-3p significantly reduced cancer cell migration and invasive abilities, suggesting these miRNAs acted as antitumor miRNAs in RCC cells. Analyses of miR-144-5p targets identified a total of 65 putative oncogenic targets in RCC cells. Among them, high expression levels of 9 genes (FAM64A, F2, TRIP13, ANKRD36, CENPF, NCAPG, CLEC2D, SDC3, and SEMA4B) were significantly associated with poor prognosis (P < .001). Among these targets, expression of SDC3 was directly controlled by miR-144-5p, and its expression enhanced cancer cell aggressiveness. We identified genes downstream by SDC3 regulation. Data showed that expression of 10 of the downstream genes (IL18RAP, SDC3, SH2D1A, GZMH, KIF21B, TMC8, GAB3, HLA-DPB2, PLEK, and C1QB) significantly predicted poor prognosis of the patients (P = .0064). These data indicated that the antitumor miR-144-5p/oncogenic SDC3 axis was deeply involved in RCC pathogenesis. Clustered miRNAs (miR-451a, miR-144-5p, and miR-144-3p) acted as antitumor miRNAs, and their targets were intimately involved in RCC pathogenesis.

miR-566 functions as an oncogene and a potential biomarker for prognosis in renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC), a heterogeneous type of cancer originating from the nephron, occupies approximately 3.9% of new carcinomas, with an increasing incidence in the past two decades. The most common subtype of renal cell carcinoma is clear cell RCC (ccRCC). Though surgery and other treatments are applied to RCC, it has the highest recurrence rate and mortality rate among the genitourinary cancers. As the study progressed, miRNAs are found to be the biomarkers for tumor diagnosis, prognosis and the targets for tumor management.

METHODS

In present study, RT-qPCR, wound scratch assay, cell proliferation assay, transwell assay and flow cytometry assay were performed to ascertain miR-566 expression level and its proliferation, migration and apoptosis in RCC. Moreover, we analyzed the relation between miR-566 expression and clinicopathological variables or overall survival from the 42 formalin-fixed paraffin-embedded (FFPE) renal cancer samples. We further evaluate prognostic values of miR-566 expression.

RESULTS

miR-566 is up-regulated in RCC tissue samples and renal carcinoma cell lines. miR-566 promotes cell proliferation, mobility and inhibits cell apoptosis in 786-O and ACHN cell lines. Cox proportional hazard regression analysis indicates that low expression of miR-566 patients have a remarkable longer overall survival in the univariate and multivariate analysis. The Kaplan-Meier survival curves show that the low expression of miR-566 patients have a remarkable longer overall survival.

CONCLUSIONS

The results of the current study demonstrate that oncogene miR-566 is a potential biomarker not only for diagnosis but also for prognosis for RCC.

ZBTB7/miR-137 Autoregulatory Circuit Promotes the Progression of Renal Carcinoma

Renal carcinoma greatly threatens human health, but the involved molecular mechanisms are far from complete understanding. As a master oncogene driving the initiation of many other cancers, ZBTB7 has not been established to be associated with renal cancer. Our data revealed that ZBTB7 is highly expressed in renal carcinoma specimens and cell lines, compared with normal cells. The silencing of ZBTB7 suppressed the proliferation and invasion of renal cancer cells. ZBTB7 overexpression rendered normal cells with higher proliferation rates and invasiveness. An animal study further confirmed the role of ZBTB7 in the growth of renal carcinoma. Moreover, miR-137 was identified to negatively regulate the expression of ZBTB7, and its abundance is inversely correlated with that of ZBTB7 in renal carcinoma specimens and cell lines. ZBTB7 overexpression may be induced by miR-137 downregulation. Interestingly, ZBTB7 can also suppress miR-137 expression by binding to its recognition site within the miR-137 promoter region. Taken together, we identified an autoregulatory loop consisting of ZBTB7 and miR-137 in gastric cancers, and targeting this pathway may be an effective strategy for renal carcinoma cancer therapy.

miR-488 inhibits cell growth and metastasis in renal cell carcinoma by targeting HMGN5

Purpose

microRNAs are thought to play crucial roles in tumorigenesis. Dysregulation of miR-488 has been implicated to be involved in several cancer progressions. However, the biological functions of miR-488 in renal cell carcinoma (RCC) remain unclear. This study aimed to explore the molecular mechanism underlying the role of miR-488 in RCC development.

Materials and methods

The expression levels of miR-488 were detected in 38 paired RCC tumor samples and cell lines by quantitative real-time polymerase chain reaction method. miR-488 was upregulated by mimics transfection in RCC cell lines. MTT, colony formation, transwell assay, flow cytometry assay, and a xenograft model were performed to determine cell proliferation, invasion, migration, epithelial-to-mesenchymal transition, and apoptosis in vitro and in vivo. Moreover, the potential target of miR-488 was verified by dual-luciferase reporter assay, quantitative real-time polymerase chain reaction, and Western blot. The correlation between miR-488 expression and its target gene expression was confirmed by Spearman’s correlation analysis in 38 selected RCC tissue samples.

Results

We found that miR-488 was remarkably downregulated in human RCC samples and cell lines compared with paired normal tissues and cell lines. Functional investigations revealed that overexpression of miR-488 significantly suppressed cell proliferation, invasion, and migration, and promoted cell apoptosis in RCC cells. Nucleosome binding protein 1 (high-mobility group nucleosome binding domain 5 [HMGN5]) was identified as a direct target of miR-488, and an inverse relationship was found between miR-488 expression and HMGN5 mRNA levels in RCC specimens. Rescue experiments suggested that restoration of HMGN5 partially abolished miR-488-mediated cell proliferation and invasion inhibition in RCC cells through regulating phosphatidylinositol 3-kinase/protein kinase B/the mammalian target of rapamycin and epithelial-to-mesenchymal transition signaling pathways.

Conclusion

These data indicated that miR-488 acted as a tumor suppressor in RCC proliferation and invasion by targeting HMGN5, which might provide potential therapeutic biomarker for RCC patients.

The deregulated microRNAome contributes to the cellular response to aneuploidy

BACKGROUND

Aneuploidy, or abnormal chromosome numbers, severely alters cell physiology and is widespread in cancers and other pathologies. Using model cell lines engineered to carry one or more extra chromosomes, it has been demonstrated that aneuploidy per se impairs proliferation, leads to proteotoxic as well as replication stress and triggers conserved transcriptome and proteome changes.

RESULTS

In this study, we analysed for the first time miRNAs and demonstrate that their expression is altered in response to chromosome gain. The miRNA deregulation is independent of the identity of the extra chromosome and specific to individual cell lines. By cross-omics analysis we demonstrate that although the deregulated miRNAs differ among individual aneuploid cell lines, their known targets are predominantly associated with cell development, growth and proliferation, pathways known to be inhibited in response to chromosome gain. Indeed, we show that up to 72% of these targets are downregulated and the associated miRNAs are overexpressed in aneuploid cells, suggesting that the miRNA changes contribute to the global transcription changes triggered by aneuploidy. We identified hsa-miR-10a-5p to be overexpressed in majority of aneuploid cells. Hsa-miR-10a-5p enhances translation of a subset of mRNAs that contain so called 5'TOP motif and we show that its upregulation in aneuploids provides resistance to starvation-induced shut down of ribosomal protein translation.

CONCLUSIONS

Our work suggests that the changes of the microRNAome contribute on one hand to the adverse effects of aneuploidy on cell physiology, and on the other hand to the adaptation to aneuploidy by supporting translation under adverse conditions.

Impact of novel oncogenic pathways regulated by antitumor miR-451a in renal cell carcinoma

Recent analyses of our microRNA (miRNA) expression signatures obtained from several types of cancer have provided novel information on their molecular pathology. In renal cell carcinoma (RCC), expression of microRNA‐451a (miR‐451a) was significantly downregulated in patient specimens and low expression of miR‐451a was significantly associated with poor prognosis of RCC patients (P = .00305) based on data in The Cancer Genome Atlas. The aims of the present study were to investigate the antitumor roles of miR‐451a and to identify novel oncogenic networks it regulated in RCC cells. Ectopic expression of miR‐451a significantly inhibited cancer cell migration and invasion by RCC cell lines, suggesting that miR‐451a had antitumor roles. To identify oncogenes regulated by miR‐451a in RCC cells, we analyzed genome‐wide gene expression data and examined information in in silico databases. A total of 16 oncogenes and were found to be possible targets of miR‐451a regulation. Interestingly, high expression of 9 genes (PMM2,CRELD2,CLEC2D,SPC25,BST2,EVL,TBX15,DPYSL3, and NAMPT) was significantly associated with poor prognosis. In this study, we focused on phosphomannomutase 2 (PMM2), which was the most strongly associated with prognosis. Overexpression of PMM2 was detected in clinical specimens and Spearman's rank test indicated a negative correlation between the expression levels of miR‐451a and PMM2 (P = .0409). Knockdown of PMM2 in RCC cells inhibited cancer cell migration and invasion, indicating overexpression of PMM2 could promote malignancy. Analytic strategies based on antitumor miRNAs is an effective tool for identification of novel pathways of cancer.

Molecular Characterization of Renal Cell Carcinoma: A Potential Three-MicroRNA Prognostic Signature

Background: Aberrantly expressed miRNAs promote renal cell carcinoma (RCC) growth and metastasis and are potentially useful biomarkers for metastatic disease. However, a consensus clinically significant miRNA signature has not been identified. To identify an miRNA signature for predicting clinical outcome in RCC patients, we used a four-pronged interconnected approach.Methods: Differentially expressed miRNAs were identified and analyzed in 113 specimens (normal kidney: 59; tumor: 54). miRNA profiling was performed in matched normal and tumor specimens from 8 patients and extended to 32 specimens. Seven aberrantly expressed miRNAs were analyzed by qPCR, and their levels were correlated with RCC subtypes and clinical outcome. miRNA signature was confirmed in The Cancer Genome Atlas RCC dataset (n = 241).Results: Discovery phase identified miR-21, miR-142-3p, miR-142-5p, miR-150, and miR-155 as significantly upregulated (2-4-fold) and miR-192 and miR-194 as downregulated (3-60-fold) in RCC; miR-155 distinguished small tumors (<4 cm) from benign oncocytomas. In univariate and multivariate analyses, miRNA combinations (miR-21+194; miR-21+142-5p+194) significantly predicted metastasis and/or disease-specific mortality; miR-21+142-5p+194 (for metastasis): P = 0.0017; OR, 0.53; 95% confidence interval (CI), 0.75-0.33; 86.7% sensitivity; 82% specificity. In the TCGA dataset, combined biomarkers associated with metastasis and overall survival (miR-21+142-5p+194: P < 0.0001; OR, 0.37; 95% CI, 0.58-0.23).Conclusions: The interconnected discovery-validation approach identified a three-miRNA signature as a potential predictor of disease outcome in RCC patients.Impact: With 10% survival at 5 years, metastatic disease presents poor prognosis for RCC patients. The three-miRNA signature discovered and validated may potentially at an early stage detect and predict metastasis, to allow early intervention for improving patient prognosis. Cancer Epidemiol Biomarkers Prev; 27(4); 464-72. ©2018 AACR.

Regulation of HMGB3 by antitumor miR-205-5p inhibits cancer cell aggressiveness and is involved in prostate cancer pathogenesis

Our recent determination of a microRNA (miRNA) expression signature in prostate cancer (PCa) revealed that miR-205-5p was significantly reduced in PCa tissues and that it acted as an antitumor miRNA. The aim of this study was to identify oncogenic genes and pathways in PCa cells that were regulated by antitumor miR-205-5p. Genome-wide gene expression analyses and in silico miRNA database searches showed that 37 genes were putative targets of miR-205-5p regulation. Among those genes, elevated expression levels of seven in particular (HMGB3, SPARC, MKI67, CENPF, CDK1, RHOU, and POLR2D) were associated with a shorter disease-free survival in a large number of patients in the The Cancer Genome Atlas (TCGA) database. We focused on high-mobility group box 3 (HMGB3) because it was the most downregulated by ectopic expression of miR-205-5p in PC3 cells and its expression was involved in PCa pathogenesis. Luciferase reporter assays showed that HMGB3 was directly regulated by miR-205-5p in PCa cells. Knockdown studies using si-HMGB3 showed that expression of HMGB3 enhanced PCa cell aggressiveness. Overexpression of HMGB3/HMGB3 was confirmed in naive PCa and castration-resistant PCa (CRPC) clinical specimens. Novel approaches to analysis of antitumor miRNA-regulated RNA networks in PCa cells may provide new insights into the pathogenic mechanisms of the disease.

MicroRNA profiling of dogs with transitional cell carcinoma of the bladder using blood and urine samples

Background

Early signs of canine transitional cell carcinoma (TCC) are frequently assumed to be caused by other lower urinary tract diseases (LUTD) such as urinary tract infections, resulting in late diagnosis of TCC which could be fatal. The development of a non-invasive clinical test for TCC could dramatically reduce mortality. To determine whether microRNAs (miRNAs) can be used as non-invasive diagnostic biomarkers, we assessed miRNA expression in blood and/or urine from dogs with clinically normal bladders (n = 28), LUTD (n = 25), and TCC (n = 17). Expression levels of 5 miRNA associated with TCC pathophysiology (miR-34a, let-7c, miR-16, miR-103b, and miR-106b) were assessed by quantitative real-time PCR.

Results

Statistical analyses using ranked ANOVA identified significant differences in miR-103b and miR-16 levels between urine samples from LUTD and TCC patients (miR-103b, p = 0.002; and miR-16, p = 0.016). No statistically significant differences in miRNA levels were observed between blood samples from LUTD versus TCC patients. Expression levels of miR-34a trended with miR-16, let-7c, and miR-103b levels in individual normal urine samples, however, this coordination was completely lost in TCC urine samples. In contrast, co-ordination of miR-34a, miR-16, let-7c, and miR-103b expression levels was maintained in blood samples from TCC patients.

Conclusions

Our combined data indicate a potential role for miR-103b and miR-16 as diagnostic urine biomarkers for TCC, and that further investigation of miR-103b and miR-16 in the dysregulation of coordinated miRNA expression in bladder carcinogenesis is warranted.

Electronic supplementary material

The online version of this article (10.1186/s12917-017-1259-1) contains supplementary material, which is available to authorized users.

Tissue-Based MicroRNAs as Predictors of Biochemical Recurrence after Radical Prostatectomy: What Can We Learn from Past Studies?

With the increasing understanding of the molecular mechanism of the microRNAs (miRNAs) in prostate cancer (PCa), the predictive potential of miRNAs has received more attention by clinicians and laboratory scientists. Compared with the traditional prognostic tools based on clinicopathological variables, including the prostate-specific antigen, miRNAs may be helpful novel molecular biomarkers of biochemical recurrence for a more accurate risk stratification of PCa patients after radical prostatectomy and may contribute to personalized treatment. Tissue samples from prostatectomy specimens are easily available for miRNA isolation. Numerous studies from different countries have investigated the role of tissue-miRNAs as independent predictors of disease recurrence, either alone or in combination with other clinicopathological factors. For this purpose, a PubMed search was performed for articles published between 2008 and 2017. We compiled a profile of dysregulated miRNAs as potential predictors of biochemical recurrence and discussed their current clinical relevance. Because of differences in analytics, insufficient power and the heterogeneity of studies, and different statistical evaluation methods, limited consistency in results was obvious. Prospective multi-institutional studies with larger sample sizes, harmonized analytics, well-structured external validations, and reasonable study designs are necessary to assess the real prognostic information of miRNAs, in combination with conventional clinicopathological factors, as predictors of biochemical recurrence.

Potential therapeutic implications of miRNAs in osteosarcoma chemotherapy

Osteosarcoma is the most common primary bone cancer in young adults and adolescents. Drug resistance is the main cause leading to therapeutical failure. The mechanisms of drug resistance of osteosarcoma have not been fully understood. Notably, recent researches associate microRNA with drug resistance in osteosarcoma cells, raising the awareness that targeting microRNAs may help in chemotherapy success. In this review, we summarize the mechanisms linking microRNAs to drug resistance and ongoing researches on microRNAs in drug response to osteosarcoma. In addition, the therapeutic potential of microRNAs in chemotherapy will also be discussed.

MicroRNA-338-3p targets SOX4 and inhibits cell proliferation and invasion of renal cell carcinoma

MicroRNA (miR)-338-3p has been reported to be involved in tumor progression and development in various types of cancer. However, the biological function of miR-338-3p and its related molecular pathways involved in the progression of renal cell carcinoma (RCC) are unknown. The present study aimed to investigate the biological role and underlying mechanism of miR-338-3p in RCC cells. It was demonstrated that miR-338-3p expression level was significantly downregulated (P<0.05) in RCC tissues and cell lines. Clinical association analysis indicated that low expression of miR-338-3p was significantly associated with advanced TNM stage and lymph node metastasis (P<0.05). Function assays revealed that restoration of miR-338-3p in RCC cells significantly inhibited cell proliferation, colony formation, migration and invasion (P<0.05). Notably, sex-determining region Y-box 4 (SOX4) was identified as a direct target of miR-338-3p in RCC cells through a luciferase reporter assay, reverse transcription-quantitative polymerase chain reaction and western blot analysis. Furthermore, SOX4 overexpression partially rescued miR-338-3p-mediated inhibition of cell proliferation, colony formation, migration and invasion in RCC cells. These results suggested that miR-338-3p functioned as a tumor suppressor in RCC cells by modulating SOX4, suggesting that miR-338-3p may have a potential use in the treatment of RCC.

Regulation of spindle and kinetochore-associated protein 1 by antitumor miR-10a-5p in renal cell carcinoma

Analysis of our original microRNA (miRNA) expression signature of patients with advanced renal cell carcinoma (RCC) showed that microRNA‐10a‐5p (miR‐10a‐5p) was significantly downregulated in RCC specimens. The aims of the present study were to investigate the antitumor roles of miR‐10a‐5p and the novel cancer networks regulated by this miRNA in RCC cells. Downregulation of miR‐10a‐5p was confirmed in RCC tissues and RCC tissues from patients treated with tyrosine kinase inhibitors (TKI). Ectopic expression of miR‐10a‐5p in RCC cell lines (786‐O and A498 cells) inhibited cancer cell migration and invasion. Spindle and kinetochore‐associated protein 1 (SKA1) was identified as an antitumor miR‐10a‐5p target by genome‐based approaches, and direct regulation was validated by luciferase reporter assays. Knockdown of SKA1 inhibited cancer cell migration and invasion in RCC cells. Overexpression of SKA1 was observed in RCC tissues and TKI‐treated RCC tissues. Moreover, analysis of The Cancer Genome Atlas database demonstrated that low expression of miR‐10a‐5p and high expression of SKA1 were significantly associated with overall survival in patients with RCC. These findings showed that downregulation of miR‐10a‐5p and overexpression of the SKA1 axis were highly involved in RCC pathogenesis and resistance to TKI treatment in RCC.

The microRNA expression signature of pancreatic ductal adenocarcinoma by RNA sequencing: anti-tumour functions of the microRNA-216 cluster

We analysed the RNA sequence-based microRNA (miRNA) signature of pancreatic ductal adenocarcinoma (PDAC). Aberrantly expressed miRNAs were successfully identified in this signature. Using the PDAC signature, we focused on 4 clustered miRNAs, miR-216a-5p, miR-216a-3p, miR-216b-5p and miR-216b-3p on human chromosome 2p16.1. All members of the miR-216 cluster were significantly reduced in PDAC specimens. Ectopic expression of these miRNAs suppressed cancer cell aggressiveness, suggesting miR-216 cluster as anti-tumour miRNAs in PDAC cells. The impact of miR-216b-3p (passenger strand of pre-miR-216b) on cancer cells is still ambiguous. Forkhead box Q1 (FOXQ1) was directly regulated by miR-216b-3p and overexpression of FOXQ1 was confirmed in clinical specimens. High expression of FOXQ1 predicted a shorter survival of patients with PDAC by Kaplan–Meier analysis. Loss-of-function assays showed that cancer cell migration and invasion activities were significantly reduced by siFOXQ1 transfectants. We investigated pathways downstream from FOXQ1 by using genome-wide gene expression analysis. Identification of the miR-216-3p/FOXQ1-mediated network in PDAC should enhance understanding of PDAC aggressiveness at the molecular level.

A three-microRNA signature as a diagnostic and prognostic marker in clear cell renal cancer: An In Silico analysis

Accumulating evidence has demonstrated that some specific miRNAs were aberrantly expressed in renal clear cell carcinoma and participated in many biological processes. The aim of this study was to investigate a panel of miRNA signature for diagnosis and prognosis of renal clear cell carcinoma (KIRC). Here, we performed a comprehensive analysis for miRNA expression profiles and corresponding clinical information of 516 KIRC patients from The Cancer Genome Atlas (TCGA). In the study, a total of 63 differentially expressed miRNAs were identified, of which 34 were up-regulated and 29 were down-regulated. We constructed a panel of three-miRNA that were significantly associated with KIRC diagnosis and KIRC patients' prognosis. The three-miRNA signature reached a sensitivity of 98.3% and a specificity of 97.2% in the diagnosis of KIRC. Using the three-miRNA signature, we classified the KIRC patients into high-risk group and low-risk group. The Kaplan- Meier curves showed that KIRC patients with high risk scores had significantly worsen overall survival (OS) and disease free survival (DFS) than KIRC patients with low risk scores. In the univariate and multivariate Cox regression analysis, three-miRNA signature was an independent prognostic factor in OS. In conclusion, the three-miRNA signature could be used as a diagnostic and prognostic biomarker in KIRC, and therefore, may help to provide significant clinical implication for the treatment of KIRC.

Low expression of microRNA-320b correlates with tumorigenesis and unfavorable prognosis in glioma

Accumulating evidence demonstrates that dysregulated microRNAs (miRNAs) play a critical role in tumorigenesis and progression of various cancers. miR-320b, a member of miR‑320 family, was revealed downregulated in numerous human cancers, including nasopharyngeal carcinoma and colorectal cancer. However, the function of miR‑320b in human glioma remained poorly defined. In this study, we report that miR‑320b was lowly expressed in glioma tissues and cell lines in contrast with controls, being closely correlated with histological malignancy of glioma. Furthermore, patients with low expression of miR‑320b were associated with poor prognostic outcomes. In vitro functional assays indicated that overexpression of miR‑320b could markedly enhance cell apoptosis rate and suppress cell proliferation, migration and invasion. miR-320b mimic impaired cell cycle and metastasis through inhibiting the expression of G1/S transition key regulator Cyclin D1 as well as decreasing the expression level of MMP2 and MMP9. Additionally, upregulation of miR‑320b could markedly promote apoptosis by increasing the level of Bax and reducing Bcl-2 expression in glioma. Taken together, our data suggested that miR‑320b might serve as a novel prognostic marker and potential therapeutic target for glioma.

microRNA-802 inhibits epithelial-mesenchymal transition through targeting flotillin-2 in human prostate cancer

miRNAs are a class of non-coding RNAs that exert critical roles in various biological processes. The aim of the present study was to identify the functional roles of miR-802 in regulating epithelial-mesenchymal transition (EMT) in prostate cancer (PCa). miR-802 expression was detected in 73 pairs of PCa samples and PCa cell lines (PC3 and DU145 cells) by qRT-PCR. Cell proliferation was detected using MTT assay, and cell apoptosis was evaluated using flow cytometry. Transwell assay was conducted to investigate cell migration and invasion. Expression analysis of a set of EMT markers was performed to explore whether miR-802 is involved in EMT program. Xenograft model was established to investigate the function of miR-802 in carcinogenesis in vivo The direct regulation of Flotillin-2 (Flot2) by miR-802 was identified using luciferase reporter assay. miR-802 was remarkably down-regulated in PCa tissues and cell lines. Gain-of-function trails showed that miR-802 serves as an 'oncosuppressor' in PCa through inhibiting cell proliferation and promoting cell apoptosis in vitro Overexpression of miR-802 significantly suppressed in vivo PCa tumor growth. Luciferase reporter analysis identified Flot2 as a direct target of miR-802 in PCa cells. Overexpressed miR-802 significantly suppressed EMT, migration and invasion in PCa cells by regulating Flot2. We identified miR-802 as a novel tumor suppressor in PCa progression and elucidated a novel mechanism of the miR-802/Flot2 axis in the regulation of EMT, which may be a potential therapeutic target.

The epigenetic landscape of renal cancer

The majority of kidney cancers are associated with mutations in the von Hippel-Lindau gene and a small proportion are associated with infrequent mutations in other well characterized tumour-suppressor genes. In the past 15 years, efforts to uncover other key genes involved in renal cancer have identified many genes that are dysregulated or silenced via epigenetic mechanisms, mainly through methylation of promoter CpG islands or dysregulation of specific microRNAs. In addition, the advent of next-generation sequencing has led to the identification of several novel genes that are mutated in renal cancer, such as PBRM1, BAP1 and SETD2, which are all involved in histone modification and nucleosome and chromatin remodelling. In this Review, we discuss how altered DNA methylation, microRNA dysregulation and mutations in histone-modifying enzymes disrupt cellular pathways in renal cancers.