MicroRNA‐487a‐3p functions as a new tumor suppressor in prostate cancer by targeting CCND1

Prostate cancer and the cell cycle: Focusing on the role of microRNAs

Prostate cancer is the most frequent solid tumor in terms of incidence and ranks second only to lung cancer in terms of cancer mortality among men. It has a considerably high mortality rate; around 375,000 deaths occurred worldwide in 2020. In 2024, the American Cancer Society estimated that the number of new prostate cancer cases will be around 299,010 cases, and the estimated deaths will be around 32,250 deaths only in the USA. Cell cycle dysregulation is inevitable in cancer etiology and is targeted by various therapies in cancer treatment. MicroRNAs (miRNAs) are small, endogenous, non-coding regulatory molecules involved in both normal and abnormal cellular events. One of the cellular processes regulated by miRNAs is the cell cycle. Although there are some exceptions, tumor suppressor miRNAs could potentially arrest the cell cycle by downregulating several molecular machineries involved in catalyzing the cell cycle progression. In contrast, oncogenic miRNAs (oncomirs) help the cell cycle to progress by targeting various regulatory proteins such as retinoblastoma (Rb) or cell cycle inhibitors such as p21 or p27, and hence may contribute to prostate cancer progression; however, this is not always the case. In this review, we emphasize how a dysregulated miRNA expression profile is linked to an abnormal cell cycle progression in prostate cancer, which subsequently paves the way to a new therapeutic option for prostate cancer.

CircPCNXL2 promotes preeclampsia progression by suppressing trophoblast cell proliferation and invasion via miR-487a-3p/interferon regulatory factor 2 axis

BACKGROUND

Preeclampsia (PE) has culminated in maternal and perinatal sickness and death across the world, affecting approximately 4.6% of pregnancies. Circular RNAs (circRNAs) have been linked to the biology of numerous pathologies, including PE. Here, we investigated the functional role of circPCNXL2 in the progression of PE.

METHODS

We employed the GEO database to get the expression profile of circPCNXL2 in patients with PE. This was followed by the detection of the expression of circPCNXL2 and miR-326 by qRT-PCR. The role of circPCNXL2 on trophoblast cell proliferation, migration, and invasion was confirmed with cell viability assays, the transwell assay, and the colony formation assay. Further, we employed dual luciferase, FISH, RNA pull-down assay and Western blot analysis to determine the interaction between the expression of circPCNXL2, miR-487a-3p, and IRF2.

RESULT

Findings from this study revealed that proliferation and migration of trophoblast cells were significantly increased in the HTR-8/SVneo cells after silencing circPCNXL2. Additionally, knockdown of circPCNXL2 remarkably increased miR-487a-3p expression, while IRF2 expression was remarkably reduced (P < 0.05), indicating the presence of complementary binding sequence on miR-487a-3p with which they sequester circPCNXL2. Rescue experiments revealed that interaction occurs between circPCNXL2, miR-487a-3p, and the IRF2 protein, indicating that circPCNXL2 expression elicits suppression of migration and proliferation of trophoblast cells via the miR-487a-3p/IRF2 pathway.

CONCLUSIONS

We demonstrated that circPCNXL2 upregulation promotes pre-eclampsia by inhibiting proliferation and migration of trophoblast cells via the miR-487a-3p/IRF2 pathway or axis.

MicroRNAs in T Cell-Immunotherapy

MicroRNAs (miRNAs) act as master regulators of gene expression in homeostasis and disease. Despite the rapidly growing body of evidence on the theranostic potential of restoring miRNA levels in pre-clinical models, the translation into clinics remains limited. Here, we review the current knowledge of miRNAs as T-cell targeting immunotherapeutic tools, and we offer an overview of the recent advances in miRNA delivery strategies, clinical trials and future perspectives in RNA interference technologies.

Tumor immune checkpoints and their associated inhibitors

Immunological evasion is one of the defining characteristics of cancers, as the immune modification of an immune checkpoint (IC) confers immune evasion capabilities to tumor cells. Multiple ICs, such as programmed cell death protein-1 (PD-1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), can bind to their respective receptors and reduce tumor immunity in a variety of ways, including blocking immune cell activation signals. IC blockade (ICB) therapies targeting these checkpoint molecules have demonstrated significant clinical benefits. This is because antibody-based IC inhibitors and a variety of specific small molecule inhibitors can inhibit key oncogenic signaling pathways and induce durable tumor remission in patients with a variety of cancers. Deciphering the roles and regulatory mechanisms of these IC molecules will provide crucial theoretical guidance for clinical treatment. In this review, we summarize the current knowledge on the functional and regulatory mechanisms of these IC molecules at multiple levels, including epigenetic regulation, transcriptional regulation, and post-translational modifications. In addition, we provide a summary of the medications targeting various nodes in the regulatory pathway, and highlight the potential of newly identified IC molecules, focusing on their potential implications for cancer diagnostics and immunotherapy.

RASAL2 regulates the cell cycle and cyclin D1 expression through PI3K/AKT signalling in prostate tumorigenesis

Prostate cancer (PCa) growth and progression are uniquely dependent on androgens, making the androgen receptor pathway a prime target for therapy; however, cancer progression to androgen independence leads to treatment failure and poor prognosis. In recent years, alternative therapeutic pathways for PCa have been extensively explored, such as the PTEN/PI3K/AKT pathway, cell cycle, and DNA repair. In the present study, we discovered that RASAL2, a RAS-GTPase-activating protein, acted as an oncogene to regulate cancer cell proliferation and the cell cycle and contributed to tumorigenesis via the PI3K/AKT/cyclin D1 pathway. First, RASAL2 expression was higher in PCa tumour and metastatic lymph node tissues than in matched adjacent nontumor tissues and was associated with higher PCa tumour stage, Gleason score and poorer prognosis. Mechanistically, we found that RASAL2 promoted tumour cell proliferation, the transition from G1 to S phase in vitro and tumour growth in vivo. Furthermore, we demonstrated that RASAL2 facilitated phosphorylation of AKT, which in turn increased the expression of cyclin D1 encoded by the CCND1 gene. In addition, there was a positive correlation between the expression of RASAL2 and cyclin D1 in subcutaneous xenografts and clinical specimens. Taken together, these findings indicate that RASAL2 plays an oncogenic role in prostate cancer and may promote PCa tumorigenesis through PI3K/AKT signalling and cyclin D1 expression.

Cyclin D1 mediated by the nuclear translocation of nuclear factor kappa B exerts an oncogenic role in lung cancer

The relevance of cyclin D1 (CCND1) has been implicated in lung cancer progression. Nevertheless, the mechanism by which CCND1 supports lung cancer development is yet to be expounded. Here, we established that CCND1 is overexpressed in clinical lung cancer specimens and various lung cancer cells. Importantly, CCND1 overexpression enhanced lung cancer cell proliferation, invasion and migration, and arrested the cell cycle at the S phase. In vivo, overexpression of CCND1 promoted lung cancer growth and metastasis. The nuclear translocation of nuclear factor kappa B (NF-κB) promoted p65 protein expression and CCND1 transcription. Meanwhile, PI3K/AKT pathway activity was significantly reduced when NF-κB nuclear translocation was decreased. PI3K/AKT pathway activity was significantly elevated upon CCND1 overexpression. Inhibition of PI3K/AKT pathway activity or suppression of NF-κB translocation in cells with high CCND1 expression was found to significantly reduce the activity of lung cancer cells in vitro and in vivo. Our data revealed that NF-κB/CCND1/PI3K/AKT axis could act as a prospective diagnostic biomarker and a therapeutic option for lung cancer.

Downregulation of miR-487a-3p suppresses the progression of non-small cell lung cancer via targeting Smad7

Non-small cell lung cancer (NSCLC) is the most prevalent type of lung cancer; however, the treatment efficacy of advanced NSCLC remains poor. MicroRNAs (miRNAs) are closely associated with the pathogenesis of lung cancer, while the detailed function of miR-487a-3p in NSCLC remains unclear. Bioinformatic analysis was performed to identify differentially expressed miRNAs (DEmiRNAs) between NSCLC and normal tissues. The effects of miR-487a-3p antagomir on the proliferation and invasion of NSCLC cells were explored with CCK-8 and Transwell assays. A total of 48 overlapping miRNAs were identified, including 9 commonly downregulated and 39 commonly upregulated miRNAs. MiR-487a-3p was found to be associated with poor survival rate of patients with NSCLC. MiR-487a-3p level was notably upregulated in NSCLC cells compared with that in human bronchial epithelial cells. Downregulation of miR-487a-3p inhibited the proliferation of NCI-H1299 and A549 cells via inducing apoptosis. In addition, miR-487a-3p antagomir significantly decreased the migration and invasion ability of NCI-H1299 cells. The results of the dual-luciferase reporter assay and western blotting indicated that miR-487a-3p antagomir exerted antitumor effects via targeting Smad7. The findings of the present study revealed that downregulation of miR-487a-3p suppressed the progression of NSCLC via inhibiting the Smads pathway, and it may serve as a novel promising target for the treatment of NSCLC.

PSMC2/CCND1 axis promotes development of ovarian cancer through regulating cell growth, apoptosis and migration

Ovarian cancer is known as one of the most common malignancies of the gynecological system, whose treatment is still not satisfactory because of the unclear understanding of molecular mechanism. PSMC2 is an essential component of 19 S regulatory granules in 26 S proteasome and its relationship with ovarian cancer is still not clear. In this study, we found that PSMC2 was upregulated in ovarian cancer tissues, associated with tumor grade and could probably predict poor prognosis. Knocking down the endogenous PSMC2 expression in ovarian cancer cells could decrease colony formation ability, cell motility and cell proliferation rate, along with increasing cell apoptosis rate. Cells models or xenografts formed by cells with relatively lower expression of PSMC2 exhibited weaker oncogenicity and slower growth rate in vivo. Moreover, gene microarray was used to analyze the alteration of gene expression profiling of ovarian cancer induced by PSMC2 knockdown and identify CCND1 as a potential downstream of PSMC2. Further study revealed the mutual regulation between PSMC2 and CCND1, and demonstrated that knockdown of CCND1 could enhance the regulatory effects induced by PSMC2 knockdown and overexpression of CCND1 reverses it. In summary, PSMC2 may promote the development of ovarian cancer through CCND1, which may predict poor prognosis of ovarian cancer patients.

miR-122 Inhibits the Cervical Cancer Development by Targeting the Oncogene RAD21

Cervical cancer (CC) is one of the most frequently diagnosed tumors in female. miR-122 has been proved to be dominant in CC. The particular role of miR-122 in CC is unclear. Thus, we attempted to investigate the prognostic role of miR-122 in CC. We used the database of Kaplan-Meier curve plot. Growth and apoptosis of C33A cells were detected by CCK-8, colony formation assay, transwell assays and flow cytometry analysis. The target gene of miR-122 was identified using bioinformatics, q-PCR, western blot and luciferase assay. It showed that CC patients with overexpression of miR-122 have a better prognosis in the Kaplan-Meier plot database analysis. Overexpressed miR-122 inhibited the malignant growth and induced apoptosis of CC. miR-122 targeting of RAD21 cohesin complex component (RAD21) was identified using bioinformatics, Q-PCR, western blot and luciferase assay analyses. Moreover, we found miR-122 conduct its functions via RAD21 via the PI3K/AKT signaling pathway. Importantly, overexpression of RAD21 restored the roles of miR-122 in CC. Our data suggested that miR-122 could block malignant growth and promoted apoptosis by targeting RAD21 in CC. Our finding indicates miR-122 could potentially participate in the pathogenesis and be a biomarker or the potential therapeutic target of CC.

Potential clinical use of miRNA molecules in the diagnosis of prostate cancer

Prostate cancer (PCa) is the most common type of cancer among men in Europe and this applies to almost the whole world. Current recommendations for screening and diagnosis are based on prostate specific antigen (PSA) measurements and the digital rectal examination (DRE). Both of them trigger the prostate biopsy. Limited specificity of the PSA test brings, however, a need to develop new and better diagnostic tools. In the last few years, new approaches for providing significantly better biomarkers, an alternative to PSA, have been introduced. Modern biomarkers show improvement not only as a diagnostic procedure, but also for staging, evaluating aggressiveness and managing the therapeutic process. The most promising group are molecular markers; among them microRNAs (miRNAs, miRs) are most frequent. miRNAs represent a class of about 22 nucleotides long, small non-coding RNAs, which are involved in gene expression regulation at the post-transcriptional level. This article reports a revision about the role of miRNAs in PCa including data of Adreno Receptor (AR) signaling, cell cycle, epithelial mesenchymal transition (EMT) process, cancer stem cells (CSCs) regulation and even the role of miRNAs as PCa therapeutic tool. Finding better PCa biomarkers, replacing the current PSA measurement, is firmly needed in modern oncology practice.

Study of microRNA Expression Profile in Different Regions of Ram Epididymis

The regional expression of epididymal genes provides a guarantee for sperm maturation. As a class of endogenous non-coding small RNAs, microRNAs (miRNAs) play an important role in spermatogenesis, maturation and fertilization. Currently, the regulatory role of miRNA in the epididymis is poorly understood. Here, transcriptome sequencing was used to analyse miRNA expression profiles in three regions of the epididymis of rams, including caput, corpus and cauda. The results showed that there were 13 known miRNAs between the caput and corpus controls, 29 between the caput and cauda and 22 differences between the corpus and cauda. Based on the analysis of miRNA target genes by GO and KEGG, a negative regulation network of miRNA-mRNA was constructed in which let-7, miR-541-5p, miR-133b and miR-150 may play an important regulatory role in the maturation regulation of ram epididymal sperm. This research provides a reference for studying the regulation mechanism of sperm maturation in male epididymis and improving semen quality and male reproductive performance.

FGFR1 regulates proliferation and metastasis by targeting CCND1 in FGFR1 amplified lung cancer

Aims: The analysis of the online databases revealed that CCND1 expression is correlated with poor prognosis in LSCC. We aimed to explore the function of CCND1 in tumor progression in LSCC.Main methods: The expression of mRNA was measured using qRT-PCR. Protein expression was assessed by Western blot. Cell migration and invasion were assessed by transwell assay.Key findings: CCND1 was co-overexpressed with FGFR1 in lung cancer patients. Overexpression of CCND1 promoted LSCC cell proliferation and metastasis. FGFR1 promoted the processes of EMT through AKT/MAPK signaling by targeting CCND1 in FGFR1-amplification cell lines.Significance: IIn conclusion, our study demonstrated the regulatory mechanism between CCND1 and FGFR1 in FGFR1 amplified LSCC. Co-targeting CCND1 and FGFR1 could provide greater clinical benefits.

The Regulating Effect of Autophagy-Related MiRNAs in Kidney, Bladder, and Prostate Cancer

Autophagy is a treatment target for many disorders, including cancer, and its specific role is becoming increasingly well known. In tumors, researchers pay attention to microribonucleic acids (miRNAs) with regulatory effects to develop more effective therapeutic drugs for autophagy and find new therapeutic targets. Various studies have shown that autophagy-related miRNAs play an irreplaceable role in different tumors, such as miR-495, miR-30, and miR-101. These miRNAs are associated with autophagy resistance in gastric cancer, non-small cell lung cancer, and cervical cancer. In recent years, autophagy-related miRNAs have also been reported to play a role in autophagy in urinary system tumors. This article reviews the regulatory effects of autophagy-related miRNAs in kidney, bladder, and prostate cancer and provides new ideas for targeted therapy of the three major tumors of the urinary system.

MicroRNA-487a-3p inhibits the growth and invasiveness of oral squamous cell carcinoma by targeting PPM1A

Oral squamous cell carcinoma (OSCC) forms the majority of the entire cancerous tumors which occur in the mouth. Current treatment advances, such as surgical resection, chemotherapy, and radiotherapy, have significantly helped reduce OSCC. However, the overall patient survival rate remains relatively low. MiRNAs, a non-coding RNA group, are essential for multiple biological functions, which are essential for the progression of cancer, including survival of the cell, migration, multiplication, differentiation, and apoptosis. The study aimed to explore the existing association between miR-487a-3p and PPM1A and elucidating their role in modulation of proliferation in OSCC cell lines. In this study, we used CAL-27 and TCA-8113 OSCC cell lines and human samples to validate our results. The manifestation of miR-487a-3p and PPM1A was checked using quantitative real-time PCR. The miR-487a-3p and PPM1A binding was investigated through western blot assay and dual-luciferase reporter gene. Functional experiments, including colony formation, CCK-8, and transwell experimentations, were undertaken to validate cells' growth and invasion activities. According to the results, the expression of miR-487a-3p is regulated in the OSCC cell lines compared to normal cells. Moreover, the mimicking of miR-487a-3p significantly reduces the OSCC cell growth and invasion, and PPM1A overexpression exerts oncogenic effects and hinders the anti-oncogenic effects of miR-487a-3p. In conclusion, the study demonstrated that miR-487a-3p might act as a tumor suppressor by inhibiting the growth and invasion of OSCC via regulating PPM1A expression.

Hsa_circ_0020095 Promotes Oncogenesis and Cisplatin Resistance in Colon Cancer by Sponging miR-487a-3p and Modulating SOX9

Objectives

Colon cancer (CC) currently ranks as the third most common human cancer worldwide with an increasing incidence and a poor prognosis. Recently, circular RNAs have been reported to regulate the progression of diverse human cancers. However, the role of circRNA hsa_circ_0020095 in CC remains largely unclear.

Methods

Expression levels of the related circRNAs, microRNAs and mRNA in CC tissues and cells were determined. The impacts of circ_0020095 or miR-487a-3p on CC cells were examined at the indicated times after transfection. Meanwhile, a luciferase-reporter experiment was employed to validate the interplay between miR-487a-3p and circ_002009695 or SOX9. Moreover, the in vivo tumor growth assay was applied to further evaluate the effects of circ_0020095 knockdown on CC progression.

Results

We demonstrated that circ_0020095 was highly expressed in CC tissues and cells. The proliferation, migration, invasion, and cisplatin resistance of CC were suppressed by silencing circ_0020095 in vitro and in vivo or by ectopic expression of miR-487a-3p in vitro. Mechanistically, circ_0020095 could directly bind to miR-487a-3p and subsequently act as a miR-487a-3p sponge to modulate the activity by targeting the 3′-UTR of SOX9. Interestingly, overexpression of circ_0020095 dramatically reversed the suppressive effects of miR-487a-3p mimics on CC cells.

Conclusion

Circ_0020095 functions as an oncogene to accelerate CC cell proliferation, invasion, migration and cisplatin resistance through the miR-487a-3p/SOX9 axis, which could be a promising target for CC treatment.

Long Noncoding RNA Small Nucleolar RNA Host Gene 3 Mediates Prostate Cancer Migration, Invasion, and Epithelial-Mesenchymal Transition by Sponging miR-487a-3p to Regulate TRIM25

Background: Long noncoding RNA small nucleolar RNA host gene 3 (SNHG3) is related to the proliferation and metastasis of cancer cells. This study aims to reveal the role of SNHG3 in prostate cancer (PCa), which may help prevent PCa metastasis. Methods: SNHG3 plasmid, SNHG3 siRNA, miR-487a-3p mimic, miR-487a-3p inhibitor, TRIM25 plasmid, and TRIM25 siRNA were transfected or cotransfected into LNCaP and PC-3 cells. The proliferation, migration, and invasion of PCa cells were measured by Cell Counting Kit-8, wound-healing, and transwell assays, respectively. The expressions of SNHG3, miR-487a-3p, E-cadherin, N-cadherin, Snail, and TRIM25 in PCa tissues and cells were measured by quantitative reverse transcription polymerase chain reaction or western blot. Results: SNHG3 expression level was upregulated in PCa tissues and cells. SNHG3 overexpression and miR-487a-3p inhibitor promoted cell viability, migration, invasion, and N-cadherin and Snail levels, and inhibited E-cadherin level in LNCaP cells, while SNHG3 silencing and miR-487a-3p mimic had the opposite effects on PC-3 cells. The inhibitory effect of miR-487a-3p mimic on the migration, invasion, and epithelial-mesenchymal transition (EMT) of LNCaP cells was inversed by both SNHG3 and TRIM25 plasmids. Similarly, the function of miR-487a-3p inhibitor in PC-3 cells was also inversed by SNHG3 siRNA and TRIM25 siRNA. Conclusion: SNHG3 mediates PCa migration, invasion, and EMT by sponging miR-487a-3p to regulate TRIM25. The Clinical Trial Registration number: Y20180831.

CircHIPK3 Alleviates High Glucose Toxicity to Human Renal Tubular Epithelial HK-2 Cells Through Regulation of miR-326/miR-487a-3p/SIRT1

BACKGROUND

The intervention of circular RNA HIPK3 (circHIPK3) in diabetes has drawn increasing attention in recent years. However, the underlying mechanism of circHIPK3 in diabetic nephropathy (DN) has not been fully elucidated. Thus, the current study aims to investigate the role of circHIPK3 in high glucose (HG)-induced toxicity to human renal tubular epithelial HK-2 cells.

METHODS

The expression of circHIPK3 in HK-2 cells induced by HG was determined by qRT-PCR and Western blot. The regulatory effects of circHIPK3 and miR-326/miR-487a-3p on cells proliferative and apoptosis were evaluated by CCK-8 and flow cytometry. Dual-luciferase reporter assay was applied to predict the target genes of miR-326 or miR-487a-3p.

RESULTS

Expression level of circHIPK3 in HK-2 cells was remarkably decreased after the treatment of HG. The overexpression of circHIPK3 effectively reversed the HG-induced HK-2 cell proliferation inhibition and apoptosis. Furthermore, SIRT1 was confirmed to be the target gene of miR-326 and miR-487a-3p, which were showed to be the downstream genes of circHIPK3. The silencing of miR-326 or miR-487a-3p was also proved to induce proliferation and reduce apoptosis in HG-induced HK-2 cells.

CONCLUSION

Our data suggest that overexpression of circHIPK3 can attenuate the proliferation inhibition of HK-2 induced by HG and inhibit apoptosis through sponging miR-326 or miR-487a-3p to regulate SIRT1.

Tumor microRNAs Identified by Small RNA Sequencing as Potential Response Predictors in Locally Advanced Rectal Cancer Patients Treated With Neoadjuvant Chemoradiotherapy

BACKGROUND/AIM

Rectal cancer accounts for approximately one-third of all colorectal cancers. Currently, the standard treatment for locally advanced rectal cancer (LARC) is neoadjuvant chemoradiotherapy (CRT) with capecitabine or 5-fluorouracil followed by curative surgery. Unfortunately, only 20% of patients with LARC present complete pathological response after CRT, whereas in 20-40% cases the response is poor or absent. The aim of our study was to evaluate whether microRNAs (miRNAs) in tumor biopsy specimen have the potential to predict therapeutic response in LARC patients.

PATIENTS AND METHODS

In total 87 LARC patients treated by CRT were enrolled in our prospective study. To identify predictive miRNAs, we used small RNA sequencing in 40 tumor biopsy samples of LARC patients (20 responders, 20 non-responders) and qPCR validation of selected miRNA candidates.

RESULTS

In the discovery phase of the study, we identified 69 miRNAs to have significantly different expression between the group of responders (TRG 1,2) and a group of non-responders (TRG 4,5) to neoadjuvant CRT. Among these miRNAs, 48 showed a lower expression and 21 showed higher expression in tumor tissues from poorly responding LARC patients. Five miRNAs were selected for validation, but only miR-487a-3p was confirmed to have a significantly higher expression in the tumor biopsy specimens of non-responders to neoadjuvant CRT (p<0.0006, AUC=0.766). Gene Ontology (GO) clustering and pathway enrichment analysis of the miR-487a-3p mRNA targets, revealed potential mechanisms behind miR-487a-3p roles in chemoradioresistance (e.g. TGF-beta signaling pathway, protein kinase activity, double-stranded DNA binding, or microRNAs in cancer).

CONCLUSION

By combination of miRNA expression profiling and integrative computational biology we identified miR-487a-3p as a potential predictive biomarker of CRT response in LARC patients.

Role of microRNAs in the development, prognosis and therapeutic response of patients with prostate cancer

Prostate cancer is the most common cancer in males in several regions. One of the major challenges in diagnosis and treatment of this cancer is how to identify men who harbor an increased risk of having clinically significant prostate cancer and how to assess response to therapy. Biomarkers, like microRNAs (miRNAs) are one of the new diagnostic/therapeutic tools for clinicians. Finding men at high risk of significant cancer is essential as they will mostly benefit from earlier diagnosis and treatment. At the same time, it is important to reduce the number of unnecessary invasive biopsies in men without (clinically significant) cancer and miRNAs have especial application in this regard. MiRNAs can regulate expression of several genes. Up to 30 percent of protein coding genes are regulated by miRNAs. Based on this critical regulatory role, miRNAs impact cell differentiation, growth and apoptosis. Several studies have reported aberrant expression of miRNAs in different cancers including prostate cancer. miRNAs are regarded as biomarkers in this kind of cancer. Moreover, expression profiles of miRNAs can predict therapeutic response to a number of drugs such docetaxel and some natural agents such as isoflavone. Functional studies have shown that miRNAs regulate a number of critical targets such as Wnt/β-catenin, PI3K/AKT, cyclin dependent kinases, VEGF and JAK/ STAT. Therefore, several aspects of prostate cancer development are influenced by miRNAs. Finally, circulating miRNAs are promising tools for assessment of prostate cancer course and prognosis. In the current review, we summarize the results of studies which reported abnormal expression of miRNAs in prostate cancer and their role as biomarkers or therapeutic targets.

MCM3AP-AS1/miR-876-5p/WNT5A axis regulates the proliferation of prostate cancer cells

BACKGROUND

Although the fact that long non-coding RNA MCM3AP antisense RNA 1 (MCM3AP-AS1) is oncogenic in several cancers is well documented, very few researchers investigate its expression and function in prostate cancer.

METHODS

Paired prostate cancer samples were selected, and expressions of MCM3AP-AS1, miR-876-5p and WNT5A were examined by qRT-PCR. MCM3AP-AS1 shRNA was transfected into LNCaP and PC-3 cell lines, and then the proliferative activity and apoptosis of cancer cells were detected by CCK-8 assay, EdU assay and flow cytometry analysis, respectively. qRT-PCR and Western blot were used to analyze the changes of miR-876-5p and WNT5A. Luciferase reporter gene assay was employed to determine the regulatory relationship between miR-876-5p and MCM3AP-AS1, miR-876-5p and WNT5A.

RESULTS

MCM3AP-AS1 was significantly up-regulated in cancerous tissues of prostate cancer samples, positively correlated with the expression of WNT5A, while negatively related with miR-876-5p. After transfection of MCM3AP-AS1 shRNA into prostate cancer cells, the proliferative ability of cancer cells was signally inhibited, but the apoptosis of cancer cells was increased. MCM3AP-AS1 shRNA could reduce the expression of WNT5A on both mRNA and protein levels. Besides, MCM3AP-AS1 was identified as a sponge of miR-876-5p. WNT5A was validated as a target gene of miR- 876-5p.

CONCLUSION

MCM3AP-AS1 is abnormally up-regulated in prostate cancer tissues and can modulate the proliferation and apoptosis of prostate cancer cells, which has the potential to be the "ceRNA" to regulate the expression of WNT5A by targeting miR-876-5p.

MiR-487a-3p suppresses the malignant development of pancreatic cancer by targeting SMAD7

OBJECTIVE

To uncover the role of microRNA-487a-3p (miR-487a-3p) in influencing the malignant development of pancreatic cancer and the involvement of its downstream target SMAD7.

METHODS

MiR-487a-3p level in 40 pancreatic cancer and paracancerous tissues was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between miR-487a-3p level and clinical indicators in pancreatic cancer patients was analyzed. Regulatory effects of miR-487a-3p on biological phenotypes of pancreatic cancer cells were assessed. At last, the involvement of miR-487a-3p and its downstream target SMAD7 in pancreatic cancer was determined.

RESULTS

MiR-487a-3p was lowly expressed in pancreatic cancer tissues. Pancreatic cancer patients expressing a low level of miR-487a-3p suffered high metastasis rate and poor prognosis. Overexpression of miR-487a-3p markedly attenuated proliferative and migratory capacities in pancreatic cancer cells. SMAD7 was the downstream target of miR-487a-3p, which was highly expressed in pancreatic cancer samples. Overexpression of SMAD7 reversed the regulatory effects of miR-487a-3p on pancreatic cancer cell phenotypes.

CONCLUSIONS

MiR-487a-3p is downregulated in pancreatic cancer samples, which is linked to metastasis and prognosis in pancreatic cancer. It inhibits the malignant development of pancreatic cancer by negatively regulating SMAD7.

miR-487a performs oncogenic functions in osteosarcoma by targeting BTG2 mRNA

Aberrant microRNA (miRNA) expression plays a critical role in osteosarcoma (OS) pathogenesis. In this study, we elucidated the involvement of miR-487a in OS and the underlying molecular mechanisms. We found that miR-487a was upregulated in OS clinical samples and cell lines. Knockdown of miR-487a suppressed OS cell growth and invasion and induced apoptosis; however, overexpression of miR-487a promoted OS cell growth and invasion. Accordingly, downregulation of miR-487a significantly suppressed tumor growth of OS xenografts in vivo. Furthermore, B-cell translocation gene 2 (BTG2) mRNA was found to be a novel target of miR-487a. Knockdown of BTG2 using small interfering RNA (siRNA) recapitulated the oncogenic effects of miR-487a, whereas BTG2 overexpression partially reversed these effects. Finally, miR-487a levels were found to be negatively correlated with BTG2 expression in OS clinical samples. Collectively, our data suggest that miR-487a is an oncogenic miRNA in OS and it lowers BTG2 expression.

LncRNA SNHG16 induces proliferation and fibrogenesis via modulating miR-141-3p and CCND1 in diabetic nephropathy

LncRNAs are reported to participate in the progression of various diseases including diabetic nephropathy. Currently, we reported that SNHG16 was obviously upregulated in db/db mice and high glucose-treated mice mesangial cells. Then, functional experiments showed that SNHG16 silencing significantly inhibited proliferation of mice mesangial cells, which induced the apoptosis and triggered cell cycle arrest. Meanwhile, proliferation-related biomarkers PCNA and Cyclin D1 (CCND1) were greatly repressed. Furthermore, western blot analysis was conducted to test fibrogenesis-associated genes Fibronectin and α-SMA. Meanwhile, the increased protein expression levels of Fibronectin and α-SMA under high glucose conditions were reversed by loss of SNHG16. miR-141-3p has been reported to be involved in various diseases. Then, RNA immunoprecipitation assay revealed the relation between SNHG16 and miR-141-3p. Downregulation of SNHG16 was able to induce expression of miR-141-3p, which was obviously reduced in db/db diabetic nephropathy mice. In addition, CCND1 is a crucial cell cycle master in human diseases. CCND1 was speculated as the target of miR-141-3p and miR-141-3p inhibited CCND1 expression significantly. Meanwhile, we observed that loss of CCND1 greatly repressed mice mesangial cell proliferation and induced cell apoptosis. Taken these together, we revealed for the first time that SNHG16 induced proliferation and fibrogenesis via modulating miR-141-3p and CCND1 in diabetic nephropathy. SNHG16/miR-141-3p/CCND1 axis can suggest a pathological mechanism of progression of diabetic nephropathy.

Role of miRNAs in prostate cancer: Do we really know everything?

Many different genetic alterations, as well as complex epigenetic interactions, are the basis of the genesis and progression of prostate cancer (CaP). This is the reason why until now the molecular pathways related to development of this cancer were only partly known, and even less those that determine aggressive or indolent tumour behaviour. MicroRNAs (miRNAs) represent a class of about 22 nucleotides long, small non-coding RNAs, which are involved in gene expression regulation at the post-transcriptional level. MiRNAs play a crucial role in regulating several biological functions and preserving homeostasis, as they carry out a wide modulatory activity on various molecular signalling pathways. MiRNA genes are placed in cancer-related genomic regions or in fragile sites, and they have been proven to be involved in the main steps of carcinogenesis as oncogenes or oncosuppressors in many types of cancer, including CaP. We performed a narrative review to describe the relationship between miRNAs and the crucial steps of development and progression of CaP. The aims of this study were to improve the knowledge regarding the mechanisms underlying miRNA expression and their target genes, and to contribute to understanding the relationship between miRNA expression profiles and CaP.

Oncogenic and tumor-suppressive microRNAs in prostate cancer

MicroRNAs are known to be dysregulated in prostate cancer. These small noncoding RNAs can function as biomarkers and are involved in the biology of prostate cancer. The canonical mechanism for microRNAs is post-transcription regulation of gene expression via binding to the 3' untranslated region of mRNAs, resulting in RNA degradation and/or translational repression. Thus, oncogenic microRNAs, also known as oncomiRs, often have high expression in prostate cancer and target the mRNAs of tumor suppressors. Conversely, tumor-suppressive microRNAs have reduced expression in cancer and typically target oncogenes. Some microRNAs function outside the classical mechanism and serve to stabilize their mRNA targets. Herein, we review contemporary studies that demonstrate oncogenic and tumor-suppressive activity of microRNAs in prostate cancer.

Cyclin D degradation by E3 ligases in cancer progression and treatment

D cyclins include three isoforms: D1, D2, and D3. D cyclins heterodimerize with cyclin-dependent kinase 4/6 (CDK4/6) to form kinase complexes that can phosphorylate and inactivate Rb. Inactivation of Rb triggers the activation of E2F transcription factors, which in turn regulate the expression of genes whose products drive cell cycle progression. Because D-type cyclins function as mitogenic sensors that link growth factor signaling directly with G₁ phase progression, it is not surprising that D cyclin accumulation is dysregulated in a variety of human tumors. Elevated expression of D cyclins results from gene amplification, increased gene transcription and protein translation, decreased microRNA levels, and inefficiency or loss of ubiquitylation-mediated protein degradation. This review focuses on the clinicopathological importance of D cyclins, how dysregulation of Ubiquitin-Proteasome System (UPS) contributes to the overexpression of D cyclins, and the therapeutic potential through targeting D cyclin-related machinery in human tumors.

Differential Expression Profiles of the Transcriptome and miRNA Interactome in Synovial Fibroblasts of Rheumatoid Arthritis Revealed by Next Generation Sequencing

Using next-generation sequencing to decipher the molecular mechanisms underlying aberrant rheumatoid arthritis synovial fibroblasts (RASF) activation, we performed transcriptome-wide RNA-seq and small RNA-seq on synovial fibroblasts from rheumatoid arthritis (RA) subject and normal donor. Differential expression of mRNA and miRNA was integrated with interaction analysis, functional annotation, regulatory network mapping and experimentally verified miRNA–target interaction data, further validated with microarray expression profiles. In this study, 3049 upregulated mRNA and 3552 downregulated mRNA, together with 50 upregulated miRNA and 35 downregulated miRNA in RASF were identified. Interaction analysis highlighted contribution of miRNA to altered transcriptome. Functional annotation revealed metabolic deregulation and oncogenic signatures of RASF. Regulatory network mapping identified downregulated FOXO1 as master transcription factor resulting in altered transcriptome of RASF. Differential expression in three miRNA and corresponding targets (hsa-miR-31-5p:WASF3, hsa-miR-132-3p:RB1, hsa-miR-29c-3p:COL1A1) were also validated. The interactions of these three miRNA–target genes were experimentally validated with past literature. Our transcriptomic and miRNA interactomic investigation identified gene signatures associated with RASF and revealed the involvement of transcription factors and miRNA in an altered transcriptome. These findings help facilitate our understanding of RA with the hope of serving as a springboard for further discoveries relating to the disease.