microRNA-196a-5p inhibits testicular germ cell tumor progression via NR6A1/E-cadherin axis

Let-7a-5p abrogates progression of papillary thyroid carcinoma cells by decreasing nuclear receptor subfamily 6 group a member 1-mediated lipogenesis

Increasing evidence shows that microRNAs (miRNAs) contribute vital roles in papillary thyroid carcinoma (PTC) carcinogenesis, proliferation, invasion, and so on. As the most common endocrine malignancy, there still have largely unknown molecular events. First, our analysis and open access database information indicates that the downregulation of let-7a-5p accelerates PTC progression. Next, lentivirus mediates the overexpression of let-7a-5p PTC cells, and found let-7a-5p suppressed cancer cells proliferation and invasion. Interestingly, bioinformatics analysis hints NR6A1 is the potential target gene of let-7a-5p. The regulation was validated by luciferase and quantitative reverse transcription polymerase chain reaction (qRT-PCR) in PTC tissue and the clinic tumors. Moreover, let-7a-5p regulated NR6A1 involved in PTC cells lipogensis in vitro and in vivo. Finally, let-7a-5p abrogates PCT xenograft tumors growth, NR6A1 expression and lipogenesis. Taken together, our data indicates that let-7a-5p suppresses PCT progression through decreased lipogenesis, the related let-7a-5p/NR6A1axis might be promising candidate targets for PTC treatment.

The potential role of miRNAs in the pathogenesis of testicular germ cell tumors - A Focus on signaling pathways interplay

Testicular germ cell tumors (TGCTs) are the most common testicular neoplasms in adolescents and young males. Understanding the genetic basis of TGCTs represents a growing need to cope with the increased incidence of these neoplasms. Although the cure rates have been comparatively increased, investigation of mechanisms underlying the incidence, progression, metastasis, recurrence, and therapy resistance is still necessary. Early diagnosis and non-compulsory clinical therapeutic agents without long-term side effects are now required to reduce the cancer burden, especially in the younger age groups. MicroRNAs (miRNAs) control an extensive range of cellular functions and exhibit a pivotal action in the development and spreading of TGCTs. Because of their dysregulation and disruption in function, miRNAs have been linked to the malignant pathophysiology of TGCTs by influencing many cellular functions involved in the disease. These biological processes include increased invasive and proliferative perspective, cell cycle dysregulation, apoptosis disruption, stimulation of angiogenesis, epithelial-mesenchymal transition (EMT) and metastasis, and resistance to certain treatments. Herein, we present an up-to-date review of the biogenesis of miRNAs, miRNA regulatory mechanisms, clinical challenges, and therapeutic interventions of TGCTs, and role of nanoparticles in the treatment of TGCTs.

miRNAs orchestration of testicular germ cell tumors - Particular emphasis on diagnosis, progression and drug resistance

Testicular cancer (TC) is one of the most frequently incident solid tumors in males. A growing prevalence has been documented in developed countries. Although recent advances have made TC an exceedingly treatable cancer, numerous zones in TC care still have divisive treatment decisions. In addition to physical examination and imaging techniques, conventional serum tumor markers have been traditionally used for the diagnosis of testicular germ cell tumors (TGCT). Unlike other genital and urinary tract tumors, recent research methods have not been broadly used in TGCTs. Even though several challenges in TC care must be addressed, a dedicated group of biomarkers could be particularly beneficial to help classify patient risk, detect relapse early, guide surgery decisions, and tailor follow-up. Existing tumor markers (Alpha-fetoprotein, human chorionic gonadotrophin, and lactate dehydrogenase) have limited accuracy and sensitivity when used as diagnostic, prognostic, or predictive markers. At present, microRNAs (miRNA or miR) play a crucial role in the process of several malignancies. The miRNAs exhibit pronounced potential as novel biomarkers since they reveal high stability in body fluids, are easily detected, and are relatively inexpensive in quantitative assays. In this review, we aimed to shed light on the recent novelties in developing microRNAs as diagnostic and prognostic markers in TC and discuss their clinical applications in TC management.

Hsa_circ_0007031 promotes the proliferation and migration of osteosarcoma cells by sponging miR-196a-5p to regulate the HOXB6

Circular RNAs (circRNAs), a subclass of noncoding RNAs, have been demonstrated to play an essential role in osteosarcoma (OS) development. However, there is still a significant gap in investigating its biological functions and underlying molecular mechanisms, and novel targets of circRNAs have yet to be fully explored. Herein, we found that hsa_circ_0007031 is noticeably raised in OS clinical tissues and cell lines. Hsa-circ-0007031 accelerates OS cell proliferation and migration in vitro and tumor growth and metastasis in vivo and is strongly linked with the stemness of cancer stem cells in OS. Mechanistically, hsa_circ_0007031 shares miRNA response elements with Homeobox B6 (HOXB6), which is identified as a novel pro-tumorigenic gene of OS. Hsa_circ_0007031 competitively binds to miR-196a-5p to prevent miR-196a-5p from lowering the level of HOXB6, which modulates chemokines of cytokine-cytokine receptor interaction signaling pathway and finally promotes OS malignant behavior. In summary, our data unveiled that hsa_circ_0007031/miR-196a-5p/HOXB6 axis-mediated cytokine-cytokine receptor interaction facilitates the progression of OS and maintains the properties of tumor stem cells, which could be a promising therapeutic target for OS.

Endothelial miR-196b-5p regulates angiogenesis via the hypoxia/miR-196b-5p/HMGA2/HIF1α loop

Angiogenesis is involved in development, reproduction, wound healing, homeostasis, and other pathophysiological events. Imbalanced angiogenesis predisposes patients to various pathological processes, such as angiocardiopathy, inflammation, and tumorigenesis. MicroRNAs (miRNAs) have been found to be important in regulating cellular processing and physiological events including angiogenesis. However, the role of miRNAs that regulate angiogenesis (angiomiRs) is not fully understood. Here, we observed a downregulation of the miR-196 family in endothelial cells upon hypoxia. Functionally, miR-196b-5p inhibited the angiogenic functions of endothelial cells in vitro and suppressed angiogenesis in Matrigel plugs and skin wound healing in vivo. Mechanistically, miR-196b-5p bound onto the 3' untranslated region (UTR) of high-mobility group AT-hook 2 (HMGA2) mRNA and repressed the translation of HMGA2, which in turn represses HIF1α accumulation in endothelial cells upon hypoxia. Together, our results establish the role of endothelial miR-196b-5p as an angiomiR that negatively regulates endothelial growth in angiogenesis via the hypoxia/miR-196b-5p/HMGA2/HIF1α loop. miR-196b-5p and its regulatory loop could be an important addition to the molecular mechanisms underlying angiogenesis and may serve as potential targets for antiangiogenic therapy.

CircRNA expression profiles in deltamethrin-susceptible and -resistant Culex pipiens pallens (Diptera: Culicidae)

The excessive and improper application of insecticides has caused the evolution of resistance in many mosquito populations, including Culex pipiens pallens (L.). Deltamethrin, a representative pyrethroid insecticide, is the most widely used synthetic insecticide in mosquito-borne control field. Comprehensively identifying genes and regulators associated with deltamethrin resistance and elucidating the manner in which they regulate this process is critical for effective control of mosquitoes. CircRNAs are the upstream regulatory factors of miRNAs and mRNAs, which play a role via the competitive endogenous RNA mechanism. In this study, we used high-throughput circRNA sequencing to identify circRNAs that were expressed differently in deltamethrin-susceptible strain (DS strain) and -resistant strain (DR strain) mosquitoes [NCBI Sequence Read Archive (SRA) database accession number: PRJNA714543]. We detected a total of 12,816 significantly differentially expressed circRNAs (DE-circRNAs). Among them, 6769 circRNAs were up-regulated and 6047 circRNAs were down-regulated in the DR strain compared to DS strain. Among the DE-circRNAs, we further screened that supercont3.352:252102|253283 was significantly over-expressed in the DR strain through qPCR multiple verification (P < 0.05).We used the divergent primer to amplify the rolling circle product and obtained the full-length sequence of supercont3.352:252102|253283 (GeneBank accession number: MW729338). Through software comparison and bioinformatics analysis, we predicted that supercont3.352:252102|253283 might participate in deltamethrin resistance by sponging cpp-miR-1671 and blocking its inhibition on CYP4G15.We further found that the expression of cpp-miR-1671 was significantly lower in DR strain (P < 0.01), while the expression of CYP4G15 was significantly higher in DR strain (P < 0.05).Taken together, the present study provided the most comprehensive circRNA expression profile of mosquitoes, and suggested that supercont3.352:252102|253283 might participate in deltamethrin resistance through the supercont3.352:252102|253283/cpp-miR-1671/CYP4G15 pathway.

MicroRNA-339-5p inhibits lipopolysaccharide-induced rat mesangial cells by regulating the Syk/Ras/c-Fos pathway

Chronic glomerulonephritis (CGN) is a disease occurred in glomeruli. The mechanism of CGN is regarded to be involved in a range of inflammatory responses. MicroRNA-339-5p (miR-339-5p) has been reported to be involved in inflammatory responses in many diseases. However, the role of miR-339-5p in CGN remains unclear. The purpose of this study was to investigate the role of miR-339-5p in lipopolysaccharide (LPS)-induced nephritis injury in vitro. The real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) and western blot (WB) were used to detect the expression of miR-339-5p and Syk/Ras/c-Fos pathway. Double luciferase was performed to identify targeted binding of miR-339-5p to Syk. Cell counting kit-8 (CCK-8) and flow cytometry were used to observe cell viability and cell cycle. Enzyme-linked immunosorbent assay (ELISA) was performed to measure the concentrations of inflammatory cytokines IL-1β, IL-10, IL-6, and TNF-α. Lipopolysaccharide (LPS) could increase HBZY-1 (rat mesangial cells) cell viability, decrease the G2 phase, and promote cell proliferation and accelerate inflammatory cytokine. However, overexpression of miR-339-5p could inhibit LPS-induced HBZY-1 cell viability, decrease the expression of Syk/Ras/c-Fos signaling pathway, downregulate the expression level of inflammatory cytokines, increase the G2 phase, and inhibit cell proliferation. miR-339-5p could inhibit the proliferation and inflammation of the rat mesangial cells through regulating Syk/Ras/c-Fos signaling pathway.

Transcriptional regulation of nuclear miRNAs in tumorigenesis (Review)

MicroRNAs (miRNAs/miRs) are a type of endogenous non‑coding small RNA that regulates gene expression. miRNAs regulate gene expression at the post‑transcriptional level by targeting the 3'‑untranslated region (3'UTR) of cytoplasmic messenger RNAs (mRNAs). Recent research has confirmed the presence of mature miRNAs in the nucleus, which bind nascent RNA transcripts, gene promoter or enhancer regions, and regulate gene expression via epigenetic pathways. Some miRNAs have been shown to function as oncogenes or tumor suppressor genes by modulating molecular pathways involved in human cancers. Notably, a novel molecular mechanism underlying the dysregulation of miRNA expression in cancer has recently been discovered, indicating that miRNAs may be involved in tumorigenesis via a nuclear function that influences gene transcription and epigenetic states, elucidating their potential therapeutic implications. The present review article discusses the import of nuclear miRNAs, nucleus‑cytoplasm transport mechanisms and the nuclear functions of miRNAs in cancer. In addition, some software tools for predicting miRNA binding sites are also discussed. Nuclear miRNAs supplement miRNA regulatory networks in cancer as a non‑canonical aspect of miRNA action. Further research into this aspect may be critical for understanding the role of nuclear miRNAs in the development of human cancers.

Hippocampal NR6A1 impairs CREB-BDNF signaling and leads to the development of depression-like behaviors in mice

Chronic stress exposure is a risk factor that can induce the development of depression-like behaviors by impairing the hippocampal cyclic adenosine monophosphate-response element binding protein (CREB)-brain-derived neurotrophic factor (BDNF) signaling, but its underlying mechanisms remain largely unknown. We identified an orphan receptor that can suppress the activity of CREB, nuclear receptor sub-family 6, group A, member 1 (NR6A1), in mouse brain neurons. Given the critical role of the impaired CREB-BDNF signaling in depression, we speculate that the neuronal NR6A1 may mediate the pathogenesis of depression. Results showed that chronic unpredictable stress (CUS) markedly increased the expression levels of hippocampal NR6A1 protein, which reduced hippocampal CREB phosphorylation and BDNF protein expression. Overexpression of hippocampal NR6A1 in stress-naïve mice simulated chronic stress, inducing depression-like behaviors in the tail suspension test, forced swimming test, and sucrose preference test, and impairing the hippocampal CREB-BDNF signaling cascade. Genetic knockdown of hippocampal NR6A1 did not affect mouse behaviors but prevented the CUS-induced depression-like behaviors in mice and impairment in hippocampal CREB-BDNF signaling. Furthermore, genetic knockdown of hippocampal CREB or BDNF abrogated the preventive effect of hippocampal NR6A1 down-regulation on CUS-induced depression-like behaviors in mice. Collectively, these results for the first time identified a nuclear expression of NR6A1 in mouse brain neurons, and showed that the abnormally increased NR6A1 protein in the hippocampus in mice treated with or without chronic stress can impair the CREB-BDNF signaling cascade and lead to the development of depression-like behaviors. Hippocampal NR6A1 could be a novel target for the development of antidepressants.

The diagnostic and prognostic values of microRNA-196a in cancer

MicroRNA-196a (miR-196a) was previously reported to be up-regulated in cancers, and it has the diagnostic and prognostic values in cancers. Whereas, the conclusion was still unclear according to the published data. To assess such roles of miR-196a in cancers, the present study was conducted based on published data and online cancer-related databases. To identify the relevant published data, we searched articles in databases and then the relevant data were extracted to evaluate the correlation between miR-196a expression and diagnosis, prognosis for cancer patients. The pooled results showed that miR-196a was a valuable diagnostic biomarker in cancer (area under curve (AUC) = 0.87, 95% CI: 0.84–0.90; sensitivity (SEN) = 0.73, 95% CI: 0.64–0.81; specificity (SPE) = 0.90, 95% CI: 0.81–0.95), which was consistent with the data from databases (breast cancer: miR-196a-3p: AUC = 0.77, 95% CI: 0.74–0.79; miR-196a-5p: AUC = 0.71, 95% CI: 0.66–0.75; pancreatic cancer: miR-196a-3p: AUC = 0.80, 95% CI: 0.73–0.87; miR-196a-5p: AUC = 0.61, 95% CI: 0.51–0.71). In addition, the pooled result revealed that elevated miR-196a expression in tumor tissues (HR = 2.54, 95% CI: 1.79–3.61, P_{Heterogeneity}=0.000, I² = 75.8%) or serum/plasma (HR = 4.06, 95% CI: 2.67–6.18, P_{Heterogeneity}=0.668, I² = 0%) of patients was an unfavorable survival biomarker, which was consistent with the data from databases (adrenocortical carcinoma: HR = 5.70; esophageal carcinoma: HR = 1.93; brain lower grade glioma: HR = 2.91; GSE40267: HR = 2.47, 95% CI: 1.2–5.07; TCGA: HR = 1.82, 95% CI: 1.21–2.74; GSE19783: HR = 4.24, 95% CI: 1–18.06). In short, our results demonstrated that miR-196a in tumor tissue or serum/plasma could be used as a prognostic and diagnostic values for cancers.