miR-15/miR-16 loss, miR-21 upregulation, or deregulation of their target genes predicts poor prognosis in prostate cancer patients

Tumor Suppressor MicroRNAs in Clinical and Preclinical Trials for Neurological Disorders

Cancers and neurological disorders are two major types of diseases in humans. We developed the concept called the "Aberrant Cell Cycle Disease (ACCD)" due to the accumulating evidence that shows that two different diseases share the common mechanism of aberrant cell cycle re-entry. The aberrant cell cycle re-entry is manifested as kinase/oncoprotein activation and tumor suppressor (TS) inactivation, which are associated with both tumor growth in cancers and neuronal death in neurological disorders. Therefore, some cancer therapies (e.g., kinase/oncogene inhibition and TS elevation) can be leveraged for neurological treatments. MicroRNA (miR/miRNA) provides a new style of drug-target binding. For example, a single tumor suppressor miRNA (TS-miR/miRNA) can bind to and decrease tens of target kinases/oncogenes, producing much more robust efficacy to block cell cycle re-entry than inhibiting a single kinase/oncogene. In this review, we summarize the miRNAs that are altered in both cancers and neurological disorders, with an emphasis on miRNA drugs that have entered into clinical trials for neurological treatment.

Plasmatic MicroRNAs and Treatment Outcomes of Patients with Metastatic Castration-Resistant Prostate Cancer: A Hospital-Based Cohort Study and In Silico Analysis

Prostate cancer (PCa) is one of the most common malignancies among men worldwide. Inevitably, all advanced PCa patients develop metastatic castration-resistant prostate cancer (mCRPC), an aggressive phase of the disease. Treating mCRPC is challenging, and prognostic tools are needed for disease management. MicroRNA (miRNA) deregulation has been reported in PCa, constituting potential non-invasive prognostic biomarkers. As such, this study aimed to evaluate the prognostic potential of nine miRNAs in the liquid biopsies (plasma) of mCRPC patients treated with second-generation androgen receptor axis-targeted (ARAT) agents, abiraterone acetate (AbA) and enzalutamide (ENZ). Low expression levels of miR-16-5p and miR-145-5p in mCRPC patients treated with AbA were significantly associated with lower progression-free survival (PFS). The two miRNAs were the only predictors of the risk of disease progression in AbA-stratified analyses. Low miR-20a-5p levels in mCRPC patients with Gleason scores of <8 were associated with worse overall survival (OS). The transcript seems to predict the risk of death regardless of the ARAT agent. According to the in silico analyses, miR-16-5p, miR-145-5p, and miR-20a-5p seem to be implicated in several processes, namely, cell cycle, proliferation, migration, survival, metabolism, and angiogenesis, suggesting an epigenetic mechanism related to treatment outcome. These miRNAs may represent attractive prognostic tools to be used in mCRPC management, as well as a step further in the identification of new potential therapeutic targets, to use in combination with ARAT for an improved treatment outcome. Despite the promising results, real-world validation is necessary.

Extracellular Vesicle-Mediated Bone Remodeling and Bone Metastasis: Implications in Prostate Cancer

Bone metastasis is the tendency of certain primary tumors to spawn and dictate secondary neoplasia in the bone. The process of bone metastasis is regulated by the dynamic crosstalk between metastatic cancer cells, cellular components of the bone marrow microenvironment (osteoblasts, osteoclasts, and osteocytes), and the bone matrix. The feed-forward loop mechanisms governs the co-option of homeostatic bone remodeling by cancer cells in bone. Recent developments have highlighted the discovery of extracellular vesicles (EVs) and their diverse roles in distant outgrowths. Several studies have implicated EV-mediated interactions between cancer cells and the bone microenvironment in synergistically promoting pathological skeletal metabolism in the metastatic site. Nevertheless, the potential role that EVs serve in arbitrating intricate sequences of coordinated events within the bone microenvironment remains an emerging field. In this chapter, we review the role of cellular participants and molecular mechanisms in regulating normal bone physiology and explore the progress of current research into bone-derived EVs in directly triggering and coordinating the processes of physiological bone remodeling. In view of the emerging role of EVs in interorgan crosstalk, this review also highlights the multiple systemic pathophysiological processes orchestrated by the EVs to direct organotropism in bone in prostate cancer. Given the deleterious consequences of bone metastasis and its clinical importance, in-depth knowledge of the multifarious role of EVs in distant organ metastasis is expected to open new possibilities for prognostic evaluation and therapeutic intervention for advanced bone metastatic prostate cancer.

TET1 is a Tumor Suppressor That Inhibits Papillary Thyroid Carcinoma Cell Migration and Invasion

BACKGROUND

Ten-eleven translocation (TET) enzymes catalyze the oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) promoting demethylation in cells. However, the expression pattern and biologic significance of TET in papillary thyroid carcinoma (PTC) remain unclear. This study aimed to elucidate the biological functions of TET1 and the miRNA and mRNA expression levels in PTC cells with downregulated TET1.

METHODS

The expression of the TET family in 49 PTC tissues and corresponding tumor-adjacent tissues, as well as PTC cell lines (BCPAP, K1, and TPC-1) and the normal thyroid epithelial cell line (Nthy-ori 3-1), were detected using quantitative real-time polymerase chain reaction. The 5hmC level was detected in PTC tissues and cell lines using immunohistochemistry and dot blot assay, respectively. After silencing the TET1 gene with siRNAs in BCPAP and TPC-1 cells, cell proliferation was detected using EdU assay. Transwell assay was used to investigate cell migration and invasion. miRNA and mRNA expression arrays were conducted in TET1-depleted BCPAP cells.

RESULTS

The expression level of TET1 decreased in PTC tissues and cell lines and was consistent with the reduction in the 5hmC level. The knockdown of the TET1 gene with siRNAs in BCPAP and TPC-1 cells, cell proliferation was detected using EdU assay. Transwell assay was used to investigate cell migration and invasion. miRNA and mRNA expression arrays were conducted in TET1-depleted BCPAP cells. WNT4, FZD4, CDK6, MCF2L, and EDN1 was upregulated as potential target genes of dysregulated miRNAs.

CONCLUSION

The study showed that TET1 dysfunction inhibited the migration and invasion of BCPAP cells and might have a potential role in the pathogenesis of PTC.

Identification and analysis of survival-associated ceRNA triplets in prostate adenocarcinoma

Prostate adenocarcinoma (PRAD) is one of the most common causes of cancer-associated mortality worldwide. Recent evidence has emphasized the role of competitive endogenous RNAs (ceRNA) in prostate cancer. However, the current understanding of the roles that ceRNAs play in survival-associated PRAD remains in its infancy. In the present study, a PRAD-specific ceRNA network was constructed by integrating long non-coding RNA (lncRNA)-microRNA (miRNA)-gene interactions using experimental and computational methods, as well as expression correlations from The Cancer Genome Atlas database. The topological features of the ceRNA network were then analyzed and the PRAD-risk lncRNAs were compared with non-risk lncRNAs within this network. It was revealed that PRAD-risk lncRNAs had a higher degree, closeness and betweenness centrality, but also had the shortest path length. Finally, 42 significant PRAD-survival-associated triplets were identified. Notably, these triplets may form a compacted subnetwork composed of only 25 nodes (5 miRNAs, 4 lncRNAs and 16 genes) and 32 edges, indicating that some nodes were involved in many triplets. Among this subnetwork, mir-21 indicated the highest degree centrality and was demonstrated to exert its oncogenic effects in prostate tumors by downregulating transforming growth factor β receptor 2 (TGFBR2). Two triplets (MIR22HG_hsa-mir-21_TGFBR2 and MIR22HG_hsa-mir-21_BCL2) were finally identified; not only were they significantly associated with PRAD survival but they also had the highest average degree in the identified subnetwork. The results from the present study provide further insights into the understanding of the potential roles and interactions of ceRNA triplets and potential prognosis markers for PRAD.

Cell-type specific expression of oncogenic and tumor suppressive microRNAs in the human prostate and prostate cancer

MiR-1 and miR-143 are frequently reduced in human prostate cancer (PCa), while miR-141 and miR-21 are frequently elevated. Consequently, these miRNAs have been studied as cell-autonomous tumor suppressors and oncogenes. However, the cell-type specificity of these miRNAs is not well defined in prostate tissue. Through two different microdissection techniques, and droplet digital RT-PCR, we quantified these miRNAs in the stroma and epithelium of radical prostatectomy specimens. In contrast to their purported roles as cell-autonomous tumor suppressors, we found miR-1 and miR-143 expression to be predominantly stromal. Conversely, miR-141 was predominantly epithelial. miR-21 was detected in both stroma and epithelium. Strikingly, the levels of miR-1 and miR-143 were significantly reduced in tumor-associated stroma, but not tumor epithelium. Gene expression analyses in human cell lines, tissues, and prostate-derived stromal cultures support the cell-type selective expression of miR-1, miR-141, and miR-143. Analyses of the PCa Genome Atlas (TCGA-PRAD) showed a strong positive correlation between stromal markers and miR-1 and miR-143, and a strong negative correlation between stromal markers and miR-141. In these tumors, loss of miR-1 and gain of miR-21 was highly associated with biochemical recurrence. These data shed new light on stromal and epithelial miRNA expression in the PCa tumor microenvironment.

Bone marrow-derived mesenchymal stem cells overexpressing MiR-21 efficiently repair myocardial damage in rats

Objective

We investigated the ability of bone marrow derived mesenchymal stem cells (BMSCs) overexpressing microRNA-21 (miR-21) to repair cardiac damage induced by anthracyclines in rats.

Methods

Sprague-Dawley (SD) rats of 2~3 weeks old were selected to isolate and culture BMSCs. A lentivirus harboring pLVX-miR-21 was generated and transfected into rat BMSCs. The rats were assigned into an untreated negative control group, and groups injected with adriamycin alone or with adriamycin followed by BMSCs, pLVX-BMSCs or pLVX-miR-21-BMSCs (n = 10 each). Proliferation and migration of cells were detected by cholecystokinin-8 (CCK- 8) and transwell. MiR-21 expression, mRNA expressions of B cell lymphoma 2 (Bcl2), BAX (BCL-2-associated X protein) and vascular endothelial growth factor (VEGF) were tested by qRT-PCR. Western blotting was applied to detect protein expressions of Bcl-2, Bax and VEGF.

Results

Using CCK- 8 and transwell assays, we found that pLVX-miR-21-BMSCs, which overexpressed miR-21, exhibited greater proliferation and migration than untransfected BMSCs or pLVX-BMSCs. Ultrasonic cardiograms and immunohistochemical analysis demonstrated that among the five groups, the pLVX-miR-21-BMSC group exhibited the most improved heart function and enhanced angiogenesis. Moreover, the pLVX-miR-21-BMSC group showed enhanced expression of Bcl-2, VEGF and Cx43 and reduced expression of Bax, BNP and troponin T.

Conclusion

These findings suggest miR-21 overexpression enhanced the proliferation, invasiveness and differentiation of BMSCs as well as expression of key factors (Bcl-2, VEGF and Bax) essential for repairing the cardiac damage induced by anthracyclines and restoring heart function.

Prognostic significance of miR-21 and PDCD4 in patients with stage II esophageal carcinoma after surgical resection

Many studies have shown that randomized clinical trial with long-term follow-up found no improvement in stage II esophageal carcinoma (EC) patients receiving preoperative neoadjuvant chemoradiotherapy or chemotherapy treatment, this limitation underscored the urgent need for novel and reliable biomarkers for prognosis and prediction in stage II EC. miR-21 is frequently over-expressed while programmed cell death 4 (PDCD4) is often down-regulated in solid tumors. This study aimed to investigate the clinicopathological and prognostic significance of miR-21 and PDCD4 expression and to elucidate any correlation between miR-21 and PDCD4 expression in stage II EC patients. The expression level of miR-21 was up-regulated while the PDCD4 protein was down-regulated in stage II EC tissues compared with the adjacent non-cancerous tissues. Analyses of the clinicopathological parameters indicated that miR-21 expression was associated with differentiation grade, T stage, and N stage. PDCD4 protein expression was associated with T stage, N stage, and tumor size. The univariate linear regression analysis suggested a significant negative correlation between miR-21 and PDCD4 expression. The Kaplan-Meier curve showed that high miR-21 expression or low PDCD4 expression predicted poor progression-free survival (PFS) and overall survival (OS) of patients with stag II EC. In conclusion, both up-regulated miR-21 and down-regulated PDCD4 expression were associated with the aggressive progression and poor prognosis of stage II EC. miR-21 and PDCD4 might be potential biomarkers of tumor progression and indicators of prognosis of stag II EC.

MiR-195 Inhibits Tumor Growth and Metastasis in Papillary Thyroid Carcinoma Cell Lines by Targeting CCND1 and FGF2

BACKGROUND

MicroRNA (miRNA) dysregulation was commonly seen in papillary thyroid carcinoma (PTC), and miR-195 was verified to be downregulated in PTC by the large data set analysis from The Cancer Genome Atlas (TCGA). Our study aimed to explore the biological functions and the underlying molecular mechanisms of miR-195 in PTC.

METHODS

The relative expression of miR-195 and its target genes were assessed by quantitative RT-PCR assay in 38 pairs of PTC and the adjacent thyroid tissues. Assays were performed to evaluate the effect of miR-195 on the proliferation, migration, and invasion in PTC cell lines. Moreover, we searched for targets of miR-195 and explored the possible molecular pathway of miR-195 in PTC.

RESULTS

We found that miR-195 was downregulated in PTC cell lines and tissues. Overexpression of miR-195 significantly inhibited cell proliferation, migration, and invasion in K1 and BCPAP cell lines. CCND1 and FGF2, which had inverse correlations with miR-195 in clinical specimens, were found to be the direct targets of miR-195. Furthermore, miR-195 might be involved in PTC tumorigenesis by suppressing the Wnt/β-catenin signaling pathway.

CONCLUSIONS

These results highlight an important role of miR-195 in the initiation and progression of PTC and implicate the potential application of miR-195 in PTC target therapy.