Upregulation of miR-21 expression is a valuable predicator of advanced clinicopathological features and poor prognosis in patients with renal cell carcinoma through the p53/p21-cyclin E2-Bax/caspase-3 signaling pathway

MicroRNA-21 in urologic cancers: from molecular mechanisms to clinical implications

The three most common kinds of urologic malignancies are prostate, bladder, and kidney cancer, which typically cause substantial morbidity and mortality. Early detection and effective treatment are essential due to their high fatality rates. As a result, there is an urgent need for innovative research to improve the clinical management of patients with urologic cancers. A type of small noncoding RNAs of 22 nucleotides, microRNAs (miRNAs) are well-known for their important roles in a variety of developmental processes. Among these, microRNA-21 (miR-21) stands out as a commonly studied miRNA with implications in tumorigenesis and cancer development, particularly in urological tumors. Recent research has shed light on the dysregulation of miR-21 in urological tumors, offering insights into its potential as a prognostic, diagnostic, and therapeutic tool. This review delves into the pathogenesis of miR-21 in prostate, bladder, and renal cancers, its utility as a cancer biomarker, and the therapeutic possibilities of targeting miR-21.

CVD phenotyping in oncologic disorders: cardio-miRNAs as a potential target to improve individual outcomes in revers cardio-oncology

With the increase of aging population and prevalence of obesity, the incidence of cardiovascular disease (CVD) and cancer has also presented an increasing tendency. These two different diseases, which share some common risk factors. Relevant studies in the field of reversing Cardio-Oncology have shown that the phenotype of CVD has a significant adverse effect on tumor prognosis, which is mainly manifested by a positive correlation between CVD and malignant progression of concomitant tumors. This distal crosstalk and the link between different diseases makes us aware of the importance of diagnosis, prediction, management and personalized treatment of systemic diseases. The circulatory system bridges the interaction between CVD and cancer, which suggests that we need to fully consider the systemic and holistic characteristics of these two diseases in the process of clinical treatment. The circulating exosome-miRNAs has been intrinsically associated with CVD -related regulation, which has become one of the focuses on clinical and basic research (as biomarker). The changes in the expression profiles of cardiovascular disease-associated miRNAs (Cardio-miRNAs) may adversely affect concomitant tumors. In this article, we sorted and screened CVD and tumor-related miRNA data based on literature, then summarized their commonalities and characteristics (several important pathways), and further discussed the conclusions of Cardio-Oncology related experimental studies. We take a holistic approach to considering CVD as a risk factor for tumor malignancy, which provides an in-depth analysis of the various regulatory mechanisms or pathways involved in the dual attribute miRNAs (Cardio-/Onco-miRNAs). These mechanisms will be key to revealing the systemic effects of CVD on tumors and highlight the holistic nature of different diseases. Therefore, the Cardio-miRNAs should be given great attention from researchers in the field of CVD and tumors, which might become new targets for tumor treatment. Meanwhile, based on the principles of precision medicine (such as the predictive preventive personalized medicine, 3PM) and reverse Cardio-oncology to better improve individual outcomes, we should consider developing personalized medicine and systemic therapy for cancer from the perspective of protecting cardiovascular function.

Chasing the Role of miRNAs in RCC: From Free-Circulating to Extracellular-Vesicle-Derived Biomarkers

Renal cell carcinoma (RCC) is the second most common cancer of the urinary system. The current therapeutic strategies are based on partial or total nephrectomy and/or targeted therapies based on immune checkpoint inhibitors to which patients are often refractory. Preventive and screening strategies do not exist and the few available biomarkers for RCC are characterized by a lack of sensitivity, outlining the need for novel noninvasive and sensitive biomarkers for early diagnosis and better disease monitoring. Blood liquid biopsy (LB) is a non- or minimally invasive procedure for a more representative view of tumor heterogeneity than a tissue biopsy, potentially allowing the real-time monitoring of cancer evolution. Growing interest is focused on the extracellular vesicles (EVs) secreted by either healthy or tumoral cells and recovered in a variety of biological matrices, blood included. EVs are involved in cell-to-cell crosstalk transferring their mRNAs, microRNAs (miRNAs), and protein content. In particular, transferred miRNAs may regulate tumorigenesis and proliferation also impacting resistance to apoptosis, thus representing potential useful biomarkers. Here, we present the latest efforts in the identification of circulating miRNAs in blood samples, focusing on the potential use of EV-derived miRNAs as RCC diagnostic and prognostic markers.

Granulosa cells undergo BPA-induced apoptosis in a miR-21-independent manner

Bisphenol A (BPA) is a harmful endocrine disrupting compound that alters not only classical cellular mechanisms but also epigenetic mechanisms. Evidence suggests that BPA-induced changes in microRNA expression can explain, in part, the changes observed at both the molecular and cellular levels. BPA is toxic to granulosa cells (GCs) as it can activate apoptosis, which is known to contribute to increased follicular atresia. miR-21 is a crucial antiapoptotic regulator in GCs, yet the exact function in a BPA toxicity model remains unclear. BPA was found to induce bovine GC apoptosis through the activation of several intrinsic factors. BPA reduced live cells counts, increased late apoptosis/necrosis, increased apoptotic transcripts (BAX, BAD, BCL-2, CASP-9, HSP70), increased the BAX/Bcl-2 ratio and HSP70 at the protein level, and induced caspase-9 activity at 12 h post-exposure. miR-21 inhibition increased early apoptosis and, while it did not influence transcript levels or caspase-9 activity, it did elevate the BAX/Bcl-2 protein ratio and HSP70 in the same manner as BPA. Overall, this study shows that miR-21 plays a molecular role in regulating intrinsic mitochondrial apoptosis; however, miR-21 inhibition did not make the cells more sensitive to BPA. Therefore, apoptosis induced by BPA in bovine GCs is miR-21 independent.

miR-21 regulates ischemic neuronal injury via the p53/Bcl-2/Bax signaling pathway

Focal cerebral ischemia leads to a large number of neuronal apoptosis, and secondary neuronal death is the main cause of cerebral infarction. MicroRNA-21 (miR-21) has been shown to be a strong anti-apoptosis and pro-survival factor in ischemia. However, the precise mechanism of miR-21 in ischemic neuroprotection remains largely unknown. In this study, miR-21 was down-regulated while p53 was up-regulated following ischemia in vitro and in vivo. Overexpression of miR-21 in vitro and in vivo substantially inhibited the expression of p53 following ischemia, while inhibition of miR-21 in vitro and in vivo promoted p53 expression following ischemia. Moreover, the miR-21/p53 axis regulated the expression of Bcl-2/Bax and abolished OGD/R-induced neuronal injury in vitro. Furthermore, overexpression of miR-21 in vivo reduced neuronal death, protected against ischemic damage, and improved neurological functions by inhibiting p53/Bcl-2/Bax signaling, while inhibition of miR-21 enhanced the p53/Bcl-2/Bax signaling and aggravated the ischemic neuronal injury in vivo. Our data uncover a novel mechanism of miR-21 in regulating cerebral ischemic neuronal injury by inhibiting p53/Bcl-2/Bax signaling pathway, which suggests that miR-21/p53 may be attractive therapeutic molecules for treatment of ischemic stroke.

A Review of Recent Research on the Role of MicroRNAs in Renal Cancer

Renal cell carcinoma (RCC) is a most common type of urologic neoplasms; it accounts for 3% of malignant tumors, with high rates of relapse and mortality. The most common types of renal cancer are clear cell carcinoma (ccRCC), papillary renal cell carcinoma (pRCC), and chromophobe renal carcinoma (chRCC), which account for 90%, 6–15%, and 2–5%, respectively, of all renal malignancies. Although surgical resection, chemotherapy, and radiotherapy are the most common treatment method for those diseases, their effects remain dissatisfactory. Furthermore, recent research shows that the treatment efficacy of checkpoint inhibitors in advanced RCC patients is widely variable. Hence, patients urgently need a new molecular biomarker for early diagnosis and evaluating the prognosis of RCC. MicroRNAs (miRNAs) belong to a family of short, non-coding RNAs that are highly conserved, have long half-life evolution, and post-transcriptionally regulate gene expression; they have been predicted to play crucial roles in tumor metastasis, invasion, angiogenesis, proliferation, apoptosis, epithelial-mesenchymal transition, differentiation, metabolism, cancer occurrence, and treatment resistance. Although some previous papers demonstrated that miRNAs play vital roles in renal cancer, such as pathogenesis, diagnosis, and prognosis, the roles of miRNAs in kidney cancer are still unclear. Therefore, we reviewed studies indexed in PubMed from 2017 to 2020, and found several studies suggesting that there are more than 82 miRNAs involved in renal cancers. The present review describes the current status of miRNAs in RCC and their roles in progression, diagnosis, therapy targeting, and prognosis of RCC.

The Cytotoxic and Apoptotic Effects of the Brown Algae Colpomenia sinuosa are Mediated by the Generation of Reactive Oxygen Species

Brown algae are a novel resource of biogenic molecules, however few studies have been conducted in the Mediterranean to assess the cytotoxic mechanisms of algal-derived compounds. This study focuses on the antineoplastic activity of extracts from non-investigated algae of the Lebanese coast, Colpomenia sinuosa. Extracts' antineoplastic activities were evaluated by MTT and trypan blue on different tumorigenic cells. Results indicated that the most potent extract was obtained by soxhlet using dichloromethane:methanol solvent (DM soxhlet) against HCT-116. Wound healing assay confirmed that this extract decreased the migration potential of HCT-116 cells with minimal effects on non-tumorigenic cells. It also induced an increase in the subG1 population as determined by flow cytometry. Western blot analysis demonstrated that apoptosis in treated HCT-116 cells was induced via upregulation of p21 protein and downregulation of the anti-apoptotic Bcl 2, which led to caspases activation. The latter, catalyzes the degradation of PARP-1, and thus suppresses cancer proliferation. Morphological alterations, further confirmed apoptosis. A strong pro-oxidant activity evidenced by the enhanced generation of reactive oxygen species (ROS) was observed in HCT-116 treated cells. Interestingly, a strong antioxidant effectively blocked effect induced by the extract. These results indicate that C. sinuosa is a source of bioactive compounds possessing pro-apoptotic and anti-migratory efficacy.

Identification and profiling of microRNAs expressed in oral buccal mucosa squamous cell carcinoma of Chinese hamster

MicroRNAs are known to play essential role in the gene expression regulation in cancer. In our research, next-generation sequencing technology was applied to explore the abnormal miRNA expression of oral squamous cell carcinoma (OSCC) in Chinese hamster. A total of 3 novel miRNAs (Novel-117, Novel-118, and Novel-135) and 11 known miRNAs (crg-miR-130b-3p, crg-miR-142-5p, crg-miR-21-3p, crg-miR-21-5p, crg-miR-542-3p, crg-miR-486-3p, crg-miR-499-5p, crg-miR-504, crg-miR-34c-5p, crg-miR-34b-5p and crg-miR-34c-3p) were identified. We conducted functional analysis, finding that 340 biological processes, 47 cell components, 46 molecular functions were associated with OSCC. Meanwhile the gene expression of Caspase-9, Caspase-3, Bax, and Bcl-2 were determined by qRT-PCR and the protein expression of PTEN and p-AKT by immunohistochemistry. Our research proposed further insights to the profiles of these miRNAs and provided a basis for investigating the regulatory mechanisms involved in oral cancer research.

MicroRNAs in cancer cell death pathways: Apoptosis and necroptosis

To protect tissues and the organism from disease, potentially harmful cells are removed through programmed cell death processes, including apoptosis and necroptosis. These types of cell death are critically controlled by microRNAs (miRNAs). MiRNAs are short RNA molecules that target and inhibit expression of many cellular regulators, including those controlling programmed cell death via the intrinsic (Bcl-2 and Mcl-1), extrinsic (TRAIL and Fas), p53-and endoplasmic reticulum (ER) stress-induced apoptotic pathways, as well as the necroptosis cell death pathway. In this review, we discuss the current knowledge of apoptosis and necroptosis pathways and how these are impaired in cancer cells. We focus on how miRNAs disrupt apoptosis and necroptosis, thereby critically contributing to malignancy. Understanding which and how miRNAs and their targets affect cell death pathways could open up novel therapeutic opportunities for cancer patients. Indeed, restoration of pro-apoptotic tumor suppressor miRNAs (apoptomiRs) or inhibition of oncogenic miRNAs (oncomiRs) represent strategies that are currently being trialed or are already applied as miRNA-based cancer therapies. Therefore, better understanding the cancer type-specific expression of apoptomiRs and oncomiRs and their underlying mechanisms in cell death pathways will not only advance our knowledge, but also continue to provide new opportunities to treat cancer.

Construction and comprehensive analysis of dysregulated long non-coding RNA-associated competing endogenous RNA network in clear cell renal cell carcinoma

OBJECTIVE

This study aimed to assess the long noncoding RNA (lncRNA)-microRNA (miRNA)-messenger RNA (mRNA) regulatory network in clear cell renal cell carcinoma (ccRCC) by gene expression analyses.

MATERIALS AND METHODS

LncRNA, miRNA, and mRNA expression profiles in ccRCC were obtained from The Cancer Genome Atlas. Differentially expressed lncRNAs, mRNAs (cut-off: |log 2 [fold change, FC])| > 2.0 and adjusted P < 0.01) and miRNAs (|log 2FC| > 1.5 and adjusted P < 0.01) were unveiled using R. Cox regression analysis was performed to identify prognostic factors of ccRCC related to overall survival (OS). A protein-protein interaction (PPI) network was constructed for differentially expressed mRNAs (DEmRNAs) by Search Tool for the Retrieval of Interacting Genes (STRING). Key hub genes were screened from top 300 DEmRNAs. LncRNA-miRNA and miRNA-mRNA regulatory network were constructed and combined into the competing endogenous RNA regulatory network. Gene ontology biological terms were screened by STRING; Kyoto Encyclopedia of Genes and Genomes pathways were identified using the "clusterProfiler" package in R.

RESULTS

A total of 2331, 1517, and 83 DEmRNAs, lncRNAs, and miRNAs were identified, respectively. Eleven lncRNAs (AC016773.1, HOTTIP, LINC00460, NALCN-AS1, PVT1, TRIM36-IT1, WT1-AS, COL18A1-AS1, LINC00443, LINC00472, and TCL6), three miRNAs (hsa-mir-21, hsa-mir-144, and hsa-mir-155), and three mRNAs (COL4A4, NOD2, and GOLGA8B) were associated with OS. Specifically, four lncRNAs (PVT1, LINC00472, TCL6, and WT1-AS1) and one mRNA (Collagen Type IV Alpha 4 Chain) were verified as independent prognostic factors by Gene Expression Profiling Interactive Analysis. Eleven key hub genes were obtained by PPI analysis. "Cell adhesion molecules (CAMs)," "chemical carcinogenesis," and "cytokine-cytokine receptor interaction" were significantly enriched in the network.

CONCLUSION

The findings clarify the pathogenesis of ccRCC and might provide potential therapeutic targets.

TAK1 mediates apoptosis via p38 involve in ischemia-induced renal fibrosis

Renal fibrosis is a common and characteristic symptom of chronic kidney disease (CKD). However, the molecular mechanisms of renal fibrosis remain elusive. Ischemia injury, as a major cause of AKI, deserves more attention in order to improve the knowledge of AKI-induced fibrosis. Transforming growth factor-β (TGF-β)-activated kinase 1 (TAK1) interacts directly with TGF-β, which play a critical role in the progression of fibrosis. Therefore, the present study aimed to investigate the role of TAK1 in the pathogenesis of ischemia-induced renal fibrosis. Compared with mice in the vehicle group, mice intraperitoneally injected with TAK1 inhibitor were found to have lower serum creatinine, less tubular damage and more mild fibrosis following ischemia-induced AKI. Furthermore, inhibition of TAK1 reduced p38 phosphorylation, decreased expression of Bax and caspase 3 and apoptosis cells in kidneys of mice treated with IR-induced AKI. Compared with vehicle-treated renal tubular epithelial cells, TAK1 overexpression cells were found to have a higher apoptosis and fibrosis index level and p38 phosphorylation following hypoxia/reoxygenation (H/R) treatment. Furthermore, the p38 inhibitor combined with TAK1 overexpression verified the role of TAK1/p38 signaling pathway in apoptosis and fibrosis index level of renal tubular epithelial cells treated with H/R. Thus, our results show that TAK1 plays an important role in the pathogenesis of ischemia-induced renal fibrosis and may mediate p38-regulated cell apoptosis.

MicroRNA-1 and MicroRNA-21 Individually Regulate Cellular Growth of Non-malignant and Malignant Renal Cells

BACKGROUND/AIM

Due to its poor prognosis, it is increasingly necessary to understand the biology of renal cell cancer (RCC). Therefore, we investigated the role of microRNAs miR-1 and miR-21 in the growth of RCC cells compared to that of non-malignant renal cells.

MATERIALS AND METHODS

Four malignant cell lines (Caki-1, 786-O, RCC4, A498) were examined regarding their cell growth, microRNA and telomerase expression, and were compared to non-malignant RC-124 renal cells.

RESULTS

Inconsistencies appeared in the panel of RCC cells regarding antiproliferative and proliferative properties of miR-1 and miR-21, respectively. Notably, and most likely due to immortaliziation, non-malignant RC-124 cells exhibited telomerase expression and activity.

CONCLUSION

miR-1 and miR-21 functionality in cancer progression, particularly in tumor growth, may be more dependent on the individual cellular context and may reflect RCC heterogeneity. Thus, both microRNAs, in combination with other stratifying biomarkers, may be useful in terms of RCC diagnosis, prognosis, or treatment response.

MiR-21 regulates the apoptosis of keloid fibroblasts by caspase-8 and the mitochondria-mediated apoptotic signaling pathway via targeting FasL

MicroRNA-21 (miR-21) has been found to be upregulated in keloid tissue and to affect the proliferation and apoptosis of keloid fibroblasts; however, the possible mechanisms remain unclear. In this study, we aimed to evaluate the role of miR-21 in FasL-induced caspase-8 activation and the mitochondria-mediated apoptotic signaling pathway in keloid fibroblasts. Our study found that the protein level of FasL was decreased by miR-21 over-expression, while being enhanced by miR-21 inhibition in keloid fibroblasts. Subsequently, the mitochondria-mediated apoptosis of keloid fibroblasts was restrained by miR-21 over-expression, as evidenced by enhanced mitochondrial membrane potential and decreased production of mitochondrial ROS. Moreover, over-expression of miR-21 inhibited the activation of the caspase-8 and the mitochondria-mediated apoptotic signaling pathway. As expected, inhibition of miR-21 had the opposite effects. Finally, silencing of FasL suppressed miR-21 inhibition-induced apoptosis by inactivation of caspase-8 and the mitochondria-mediated apoptotic signaling pathway, which was comparable to Z-IETD-FMK, a caspase-8 inhibitor. Taken together, these results suggest that miR-21 regulates the apoptosis of keloid fibroblasts via targeting FasL, and caspase-8 and the mitochondria-mediated apoptotic signaling pathway is involved in this process. Our findings provide evidence that miR-21 may be considered to be a therapeutic target for keloids.

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.