MiR-148a attenuates paclitaxel resistance of hormone-refractory, drug-resistant prostate cancer PC3 cells by regulating MSK1 expression

Evaluation of miR-148a-3p and miR-106a-5p as Biomarkers for Prostate Cancer: Pilot Study

MicroRNAs (miRNAs) are a class of small non-coding RNAs that may function as tumor suppressors or oncogenes. Alteration of their expression levels has been linked to a range of human malignancies, including cancer. The objective of this investigation is to assess the relative expression levels of certain miRNAs to distinguish between prostate cancer (PCa) from benign prostatic hyperplasia (BPH). Blood plasma was collected from 66 patients diagnosed with BPH and 58 patients with PCa. Real-time PCR technology was used to evaluate the relative expression among the two groups for miR-106a-5p and miR-148a-3p. The significant downregulation of both miRNAs in plasma from PCa versus BPH patients suggests their potential utility as diagnostic biomarkers for distinguishing between these conditions. The concurrent utilization of these two miRNAs slightly enhanced the sensitivity for discrimination among the two analyzed groups, as shown in ROC curve analysis. Further validation of these miRNAs in larger patient cohorts and across different stages of PCa may strengthen their candidacy as clinically relevant biomarkers for diagnosis and prognosis.

Regulatory miRNAs in cancer cell recovery from therapy exposure and its implications as a novel therapeutic strategy for preventing disease recurrence

The desired outcome of cancer therapies is the eradication of disease. This can be achieved when therapy exposure leads to therapy-induced cancer cell death as the dominant outcome. Theoretically, a permanent therapy-induced growth arrest could also contribute to a complete response, which has the potential to lead to remission. However, preclinical models have shown that therapy-induced growth arrest is not always durable, as recovering cancer cell populations can contribute to the recurrence of cancer. Significant research efforts have been expended to develop strategies focusing on the prevention of recurrence. Recovery of cells from therapy exposure can occur as a result of several cell stress adaptations. These include cytoprotective autophagy, cellular quiescence, a reversable form of senescence, and the suppression of apoptosis and necroptosis. It is well documented that microRNAs regulate the response of cancer cells to anti-cancer therapies, making targeting microRNAs therapeutically a viable strategy to sensitization and the prevention of recovery. We propose that the use of microRNA-targeting therapies in prolonged sequence, that is, a significant period after initial therapy exposure, could reduce toxicity from the standard combination strategy, and could exploit new epigenetic states essential for cancer cells to recover from therapy exposure. In a step toward supporting this strategy, we survey the available scientific literature to identify microRNAs which could be targeted in sequence to eliminate residual cancer cell populations that were arrested as a result of therapy exposure. It is our hope that by successfully identifying microRNAs which could be targeted in sequence we can prevent disease recurrence.

Deregulated microRNAs Involved in Prostate Cancer Aggressiveness and Treatment Resistance Mechanisms

Prostate cancer (PCa) is the most frequently diagnosed cancer and the second leading cause of cancer deaths among American men. Complex genetic and epigenetic mechanisms are involved in the development and progression of PCa. MicroRNAs (miRNAs) are short noncoding RNAs that regulate protein expression at the post-transcriptional level by targeting mRNAs for degradation or inhibiting protein translation. In the past two decades, the field of miRNA research has rapidly expanded, and emerging evidence has revealed miRNA dysfunction to be an important epigenetic mechanism underlying a wide range of diseases, including cancers. This review article focuses on understanding the functional roles and molecular mechanisms of deregulated miRNAs in PCa aggressiveness and drug resistance based on the existing literature. Specifically, the miRNAs differentially expressed (upregulated or downregulated) in PCa vs. normal tissues, advanced vs. low-grade PCa, and treatment-responsive vs. non-responsive PCa are discussed. In particular, the oncogenic and tumor-suppressive miRNAs involved in the regulation of (1) the synthesis of the androgen receptor (AR) and its AR-V7 splice variant, (2) PTEN expression and PTEN-mediated signaling, (3) RNA splicing mechanisms, (4) chemo- and hormone-therapy resistance, and (5) racial disparities in PCa are discussed and summarized. We further provide an overview of the current advances and challenges of miRNA-based biomarkers and therapeutics in clinical practice for PCa diagnosis/prognosis and treatment.

Paclitaxel and docetaxel resistance in prostate cancer: Molecular mechanisms and possible therapeutic strategies

Prostate cancer is among most malignant tumors around the world and this urological tumor can be developed as result of genomic mutations and their accumulation during progression towards advanced stage. Due to lack of specific symptoms in early stages of prostate cancer, most cancer patients are diagnosed in advanced stages that tumor cells display low response to chemotherapy. Furthermore, genomic mutations in prostate cancer enhance the aggressiveness of tumor cells. Docetaxel and paclitaxel are suggested as well-known compounds for chemotherapy of prostate tumor and they possess a similar function in cancer therapy that is based on inhibiting depolymerization of microtubules, impairing balance of microtubules and subsequent delay in cell cycle progression. The aim of current review is to highlight mechanisms of paclitaxel and docetaxel resistance in prostate cancer. When oncogenic factors such as CD133 display upregulation and PTEN as tumor-suppressor shows decrease in expression, malignancy of prostate tumor cells enhances and they can induce drug resistance. Furthermore, phytochemicals as anti-tumor compounds have been utilized in suppressing chemoresistance in prostate cancer. Naringenin and lovastatin are among the anti-tumor compounds that have been used for impairing progression of prostate tumor and enhancing drug sensitivity. Moreover, nanostructures such as polymeric micelles and nanobubbles have been utilized in delivery of anti-tumor compounds and decreasing risk of chemoresistance development. These subjects are highlighted in current review to provide new insight for reversing drug resistance in prostate cancer.

Molecular Mechanisms of Noncoding RNA in the Occurrence of Castration-Resistant Prostate Cancer

Although several therapeutic options have been shown to improve survival of most patients with prostate cancer, progression to castration-refractory state continues to present challenges in clinics and scientific research. As a highly heterogeneous disease entity, the mechanisms of castration-resistant prostate cancer (CRPC) are complicated and arise from multiple factors. Among them, noncoding RNAs (ncRNAs), the untranslated part of the human transcriptome, are closely related to almost all biological regulation, including tumor metabolisms, epigenetic modifications and immune escape, which has encouraged scientists to investigate their role in CRPC. In clinical practice, ncRNAs, especially miRNAs and lncRNAs, may function as potential biomarkers for diagnosis and prognosis of CRPC. Therefore, understanding the molecular biology of CRPC will help boost a shift in the treatment of CRPC patients. In this review, we summarize the recent findings of miRNAs and lncRNAs, discuss their potential functional mechanisms and highlight their clinical application prospects in CRPC.

miR-143 mediates abiraterone acetate resistance by regulating the JNK/Bcl-2 signaling pathway in prostate cancer

Background: miR-143 is known to be downregulated in various cancer cells and tumors and generally plays a tumor-suppressor role. miR-143. However, the role of miR-143 in the mediation of the sensitivity of prostate cancer cells to abiraterone acetate remains unrevealed. Methods: The expression levels of miRNAs were determined by miRNA microarray and quantitative real-time PCR (qRT-PCR). The protein levels were assessed by Western blot assay. Cell viability and apoptosis were respectively measured by Cell Counting Kit-8 (CCK-8) assay and flow cytometry. Results: We identified that miR-143 was significantly downregulated in PC3-AbiR cells compared to PC3 cells. Overexpression of miR-143 promoted PC-AbiR sensitivity to abiraterone acetate in vitro and in vivo. We also revealed that miR-143 upregulation inhibited p-JNK (c-Jun N-terminal kinases) and increased p-Bcl2 (B-cell lymphoma 2), contributing to abiraterone acetate-induced apoptosis in PC3-AbiR cells. Finally, we showed that the combination of miR-143 and abiraterone acetate exerted the most profound tumor inhibition effect and prolonged the mice survival rate in PC3-AbiR tumor-bearing mice. Conclusion: Upregulation of miR-143 may serve as a new strategy to enhance the therapeutical effect of abiraterone acetate on prostate cancer patients who are resistant to abiraterone acetate.

Micro RNA 148a induces apoptosis and prevents angiogenesis with bevacizumab in colon cancer through direct inhibition of ROCK1/c-Met via HIF-1α under hypoxia

Angiogenesis and antiapoptosis effects are the major factors influencing malignancy progression. Hypoxia induces multiple mechanisms involving microRNA (miRNA) activity. Vascular endothelial growth factor (VEGF) is correlated with angiogenesis. An antiapoptotic factor, myeloid leukemia 1 (Mcl-1) is the main regulator of cell death. This study examined the role of miR-148a in inhibiting VEGF and Mcl-1 secretion by directly targeting ROCK1/c-Met by downregulating HIF-1α under hypoxia. The protein expression of ROCK1 or Met/HIF-1α/Mcl-1 in HCT116 and HT29 cells (all P < 0.05) was significantly reduced by miR-148a. The tube-formation assay revealed that miR-148a significantly suppressed angiogenesis and synergistically enhanced the effects of bevacizumab (both P < 0.05). The MTT assay revealed the inhibitory ability of miR-148a in HCT116 and HT29 cells (both P < 0.05). miR-148a and bevacizumab exerted synergistic antitumorigenic effects (P < 0.05) in an animal model. Serum miR-148a expression of metastatic colorectal cancer (mCRC) patients with a partial response was higher than that of mCRC patients with disease progression (P = 0.026). This result revealed that miR-148a downregulated HIF-1α/VEGF and Mcl-1 by directly targeting ROCK1/c-Met to decrease angiogenesis and increase the apoptosis of colon cancer cells. Furthermore, serum miR-148a levels have prognostic/predictive value in patients with mCRC receiving bevacizumab.

Curcumin Upregulates miR-148a to Increase the Chemosensitivity of CD44-Positive Prostate Cancer Stem Cells to Paclitaxel Through Targeting the MSK1/IRS1 axis

BACKGROUND

In men, prostate cancer (PC) is the second most common cause of cancer-related death. However, paclitaxel resistance is a major challenge in advanced PC. Curcumin, a natural antioxidant, has been demonstrated to have cytotoxic effects on cancer stem cells (CSCs). The goal of this study is to explore if curcumin can help lower chemoresistance to paclitaxel through the regulation of miR-148a-mediated apoptosis in prostate CSCs.

METHODS

The 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay and 4',6-diamidino-2-phenylindole (DAPi) labeling were used to determine cell survival. Immunohistochemistry was used to detect the expression of P-glycoprotein protein (P-gp) and CD44 proteins. Finally, real-time PCR was used to evaluate the regulatory effects of curcumin and paclitaxel on miR-148a and its target genes.

RESULTS

Curcumin and paclitaxel co-treatment significantly reduced the IC₅₀ value in CD44⁺cells compared to paclitaxel alone. Additionally, combining these drugs considerably increased apoptosis in CD44⁺cells. We also discovered that when curcumin and paclitaxel were combined, the expression of CD44 and P-gp was significantly reduced compared to paclitaxel alone. Curcumin and paclitaxel co-treatment also increased miR-148a levels and regulated the levels of its target genes MSK1 and IRS1.

CONCLUSION

Curcumin may restore paclitaxel sensitivity by raising miR-148a expression and inhibiting its target genes.

MicroRNAs as biomarkers for prostate cancer prognosis: a systematic review and a systematic reanalysis of public data

Background

Reliable prognostic biomarkers to distinguish indolent from aggressive prostate cancer (PCa) are lacking. Many studies investigated microRNAs (miRs) as PCa prognostic biomarkers, often reporting inconsistent findings. We present a systematic review of these; also systematic reanalysis of public miR-profile datasets to identify tissue-derived miRs prognostic of biochemical recurrence (BCR) in patients undergoing radical prostatectomy.

Methods

Independent PubMed searches were performed for relevant articles from January 2007 to December 2019. For the review, 128 studies were included. Pooled-hazard-ratios (HRs) for miRs in multiple studies were calculated using a random-effects model (REM). For the reanalysis, five studies were included and Cox proportional-hazard models, testing miR association with BCR, performed for miRs profiled in all.

Results

Systematic review identified 120 miRs as prognostic. Five (let-7b-5p, miR-145-5p, miR152-3p, miR-195-5p, miR-224-5p) were consistently associated with progression in multiple cohorts/studies. In the reanalysis, ten (let-7a-5p, miR-148a-3p, miR-203a-3p, miR-26b-5p, miR30a-3p, miR-30c-5p, miR-30e-3p, miR-374a-5p, miR-425-3p, miR-582-5p) were significantly prognostic of BCR. Of these, miR-148a-3p (HR = 0.80/95% CI = 0.68-0.94) and miR-582-5p (HR = 0.73/95% CI = 0.61-0.87) were also reported in prior publication(s) in the review.

Conclusions

Fifteen miRs were consistently associated with disease progression in multiple publications or datasets. Further research into their biological roles is warranted to support investigations into their performance as prognostic PCa biomarkers.

Effects of Anti-Cancer Drug Sensitivity-Related Genetic Differences on Therapeutic Approaches in Refractory Papillary Thyroid Cancer

Thyroid cancer (TC) includes tumors of follicular cells; it ranges from well differentiated TC (WDTC) with generally favorable prognosis to clinically aggressive poorly differentiated TC (PDTC) and undifferentiated TC (UTC). Papillary thyroid cancer (PTC) is a WDTC and the most common type of thyroid cancer that comprises almost 70–80% of all TC. PTC can present as a solid, cystic, or uneven mass that originates from normal thyroid tissue. Prognosis of PTC is excellent, with an overall 10-year survival rate >90%. However, more than 30% of patients with PTC advance to recurrence or metastasis despite anti-cancer therapy; consequently, systemic therapy is limited, which necessitates expansion of improved clinical approaches. We strived to elucidate genetic distinctions due to patient-derived anti-cancer drug-sensitive or -resistant PTC, which can support in progress novel therapies. Patients with histologically proven PTC were evaluated. PTC cells were gained from drug-sensitive and -resistant patients and were compared using mRNA-Seq. We aimed to assess the in vitro and in vivo synergistic anti-cancer effects of a novel combination therapy in patient-derived refractory PTC. This combination therapy acts synergistically to promote tumor suppression compared with either agent alone. Therefore, genetically altered combination therapy might be a novel therapeutic approach for refractory PTC.

Diagnostic, Prognostic, and Therapeutic Value of miR-148b in Human Cancers

MicroRNAs (miRs) is a class of conserved, small, noncoding RNA molecules that modulate gene expression post-transcriptionally. miR-148b is a member of miR- 148/152 family generally known to be a tumor suppressor via its effect on different signaling pathways and regulatory genes. Aberrant expression of miR-148b has recently been shown to be responsible for tumorigenesis of several different cancer types. This review discusses the current evidence regarding the involvement of miR-148b expression in human cancers and its potential clinical importance for tumor diagnosis, prognosis, and therapeutics.

A review of the biological role of miRNAs in prostate cancer suppression and progression

Prostate cancer (PC) is the third-leading cause of cancer-related deaths worldwide. Although the current treatment strategies are progressing rapidly, PC is still representing a substantial medical problem for affected patients. Several factors are involved in PC initiation, progression, and treatments failure including microRNAs (miRNAs). The miRNAs are endogenous short non-coding RNA sequence negatively regulating target mRNA expression via degradation or translation repression. miRNAs play a pivotal role in PC pathogenesis through its ability to initiate the induction of cancer stem cells (CSCs) and proliferation, as well as sustained cell cycle, evading apoptosis, invasion, angiogenesis, and metastasis. Furthermore, miRNAs regulate major molecular pathways affecting PC such as the androgen receptor (AR) pathway, p53 pathway, PTEN/PI3K/AKT pathway, and Wnt/β-catenin pathway. Furthermore, miRNAs alter PC therapeutic response towards the androgen deprivation therapy (ADT), chemotherapy and radiation therapy (RT). Thus, the understanding and profiling of the altered miRNAs expression in PC could be utilized as a non-invasive biomarker for the early diagnosis as well as for patient sub-grouping with different prognoses for individualized treatment. Accordingly, in the current review, we summarized in updated form the roles of various oncogenic and tumor suppressor (TS) miRNAs in PC, revealing their underlying molecular mechanisms in PC initiation and progression.

Identification of miRNA-Small Molecule Associations by Continuous Feature Representation Using Auto-Encoders

MicroRNAs (miRNAs) are short non-coding RNAs that play important roles in the body and affect various diseases, including cancers. Controlling miRNAs with small molecules is studied herein to provide new drug repurposing perspectives for miRNA-related diseases. Experimental methods are time- and effort-consuming, so computational techniques have been applied, relying mostly on biological feature similarities and a network-based scheme to infer new miRNA–small molecule associations. Collecting such features is time-consuming and may be impractical. Here we suggest an alternative method of similarity calculation, representing miRNAs and small molecules through continuous feature representation. This representation is learned by the proposed deep learning auto-encoder architecture. Our suggested representation was compared to previous works and achieved comparable results using 5-fold cross validation (92% identified within top 25% predictions), and better predictions for most of the case studies (avg. of 31% vs. 25% identified within the top 25% of predictions). The results proved the effectiveness of our proposed method to replace previous time- and effort-consuming methods.

Depletion of tumor suppressor miRNA-148a in plasma relates to tumor progression and poor outcomes in gastric cancer

Recent studies identified that low levels of tumor suppressor microRNAs in plasma/serum relate to tumor progression and poor outcomes in cancers. This study explored decreased tumor suppressor microRNA (miRNA) plasma levels in gastric cancer (GC) patients to clarify their potential as novel biomarkers and therapeutic targets. We focused on five candidates (miR-148a, miR-101, miR-129, miR-145 and miR-206) of tumor suppressor miRNAs in GC by a systematic review of NCBI database. Of these, miR-148a levels were significantly down-regulated in plasma of GC patients compared to healthy volunteers by test- and validation-scale analyses (P<0.0001). A Low level of plasma miR-148a was significantly associated with venous invasion, lymph node metastasis, advanced stage and peritoneal recurrence, and was an independent poor prognostic factor (P=0.0296, Hazard ratio 4.2). Overexpression of miR-148a in GC cells inhibited cell proliferation, migration, invasion and epithelial-mesenchymal transition. In vivo, the restoration and maintenance of miR-148a in plasma significantly inhibited tumor growth in mice with peritoneal metastasis (P=0.0050). In conclusions, depletion of the tumor suppressor miRNA-148a in plasma relates to tumor progression and poor outcomes. The restoration of the blood miR-148a level might be a novel nucleic acid anticancer therapy for GC.

Lovastatin enhances chemosensitivity of paclitaxel-resistant prostate cancer cells through inhibition of CYP2C8

Chemotherapy is the mainstay of treatment for prostate cancer, with paclitaxel being commonly used for hormone-resistant prostate cancer. However, drug resistance often develops and leads to treatment failure in a variety of prostate cancer patients. Therefore, it is necessary to enhance the sensitivity of prostate cancer to chemotherapy. Lovastatin (LV) is a natural compound extracted from Monascus-fermented foods and is an inhibitor of HMG-CoA reductase (HMGCR), which has been approved by the FDA for hyperlipidemia treatment. We have previously found that LV could inhibit the proliferation of refractory cancer cells. Up to now, the effect of LV on chemosensitization and the mechanisms involved have not been evaluated in drug-resistant prostate cancer. In this study, we used prostate cancer cell line PC3 and its paclitaxel-resistant counterpart PC3-TxR as the cell model. Alamar Blue cell viability assay showed that LV and paclitaxel each conferred concentration-dependent inhibition of PC3-TxR cells. When paclitaxel was combined with LV, the proliferation of PC3-TxR cells was synergistically inhibited, as demonstrated by combination index <1. Moreover, colony formation decreased while apoptosis increased in paclitaxel plus LV group compared with paclitaxel alone group. Quantitative RT-PCR showed that the combination of paclitaxel and LV could significantly reduce the expression of CYP2C8, an important drug-metabolizing enzyme. Bioinformatics analysis from the TCGA database showed that CYP2C8 expression was negatively correlated with progression-free survival (PFS) in prostate cancer patients. Our results suggest that LV might increase the sensitivity of resistant prostate cancer cells to paclitaxel through inhibition of CYP2C8 and could be utilized as a chemosensitizer for paclitaxel-resistant prostate cancer cells.

MicroRNA and Alternative mRNA Splicing Events in Cancer Drug Response/Resistance: Potent Therapeutic Targets

Cancer is a multifaceted disease that involves several molecular mechanisms including changes in gene expression. Two important processes altered in cancer that lead to changes in gene expression include altered microRNA (miRNA) expression and aberrant splicing events. MiRNAs are short non-coding RNAs that play a central role in regulating RNA silencing and gene expression. Alternative splicing increases the diversity of the proteome by producing several different spliced mRNAs from a single gene for translation. MiRNA expression and alternative splicing events are rigorously regulated processes. Dysregulation of miRNA and splicing events promote carcinogenesis and drug resistance in cancers including breast, cervical, prostate, colorectal, ovarian and leukemia. Alternative splicing may change the target mRNA 3'UTR binding site. This alteration can affect the produced protein and may ultimately affect the drug affinity of target proteins, eventually leading to drug resistance. Drug resistance can be caused by intrinsic and extrinsic factors. The interplay between miRNA and alternative splicing is largely due to splicing resulting in altered 3'UTR targeted binding of miRNAs. This can result in the altered targeting of these isoforms and altered drug targets and drug resistance. Furthermore, the increasing prevalence of cancer drug resistance poses a substantial challenge in the management of the disease. Henceforth, molecular alterations have become highly attractive drug targets to reverse the aberrant effects of miRNAs and splicing events that promote malignancy and drug resistance. While the miRNA-mRNA splicing interplay in cancer drug resistance remains largely to be elucidated, this review focuses on miRNA and alternative mRNA splicing (AS) events in breast, cervical, prostate, colorectal and ovarian cancer, as well as leukemia, and the role these events play in drug resistance. MiRNA induced cancer drug resistance; alternative mRNA splicing (AS) in cancer drug resistance; the interplay between AS and miRNA in chemoresistance will be discussed. Despite this great potential, the interplay between aberrant splicing events and miRNA is understudied but holds great potential in deciphering miRNA-mediated drug resistance.

miR-33b-3p Acts as a Tumor Suppressor by Targeting DOCK4 in Prostate Cancer

Despite that androgen-deprivation therapy results in long-lasting responses, the disease inevitably progresses to metastatic castration-resistant prostate cancer. In this study, we identified miR-33b-3p as a tumor suppressor in prostate cancer. miR-33b-3p was significantly reduced in prostate cancer tissues, and the low expression of miR-33b-3p was correlated with poor overall survival of prostate cancer patients. Overexpression of miR-33b-3p inhibited both migration and invasion of highly metastatic prostate cancer cells whereas inhibition of miR-33b-3p promoted those processes in lowly metastatic cells. The in vivo results demonstrate that miR-33b-3p suppresses metastasis of tail vein inoculated prostate cancer cells to lung and lymph nodes in mice. DOCK4 was validated as the direct target of miR-33b-3p. miR-33b-3p decreased the expression of DOCK4 and restoration of DOCK4 could rescue miR-33b-3p inhibition on cell migration and invasion. Moreover, downregulation of miR-33b-3p was induced by bortezomib, the clinically used proteasome inhibitor, and overexpression of miR-33b-3p enhanced the insufficient inhibition of bortezomib on migration and invasion as well as metastasis of prostate cancer cells. In summary, our findings demonstrate that miR-33b-3p suppresses metastasis by targeting DOCK4 in prostate cancer. Our results suggest that enhancing miR-33b-3p expression may provide a promising therapeutic strategy for overcoming that proteasome inhibitor’s poor efficacy against metastatic prostate cancer.

Host miRNA and immune cell interactions: relevance in nano-therapeutics for human health

Around 2200 miRNA (microRNA) genes were found in the human genome. miRNAs are arranged in clusters within the genome and share the same transcriptional regulatory units. It has been revealed that approximately 50% of miRNAs elucidated in the genome are transcribed from non-protein-coding genes, and the leftover miRNAs are present in the introns of coding sequences. We are now approaching a stage in which miRNA diagnostics and therapies can be established confidently, and several commercial efforts are underway to carry these innovations from the bench to the clinic. MiRNAs control many of the significant cellular activities such as production, differentiation, growth, and metabolism. Particularly in the immune system, miRNAs have emerged as a crucial biological component during diseased state and homeostasis. miRNAs have been found to regulate inflammatory responses and autoimmune disorders. Moreover, each miRNA targets multiple genes simultaneously, making miRNAs promising tools as diagnostic biomarkers and as remedial targets. Still, one of the major obstacles in miRNA-based approaches is the achievement of specific and efficient systemic delivery of miRNAs. To overcome these challenges, nanoformulations have been synthesized to protect miRNAs from degradation and enhance cellular uptake. The current review deals with the miRNA-mediated regulation of the recruitment and activation of immune cells, especially in the tumor microenvironment, viral infection, inflammation, and autoimmunity. The nano-based miRNA delivery modes are also discussed here, especially in the context of immune modulation.

Heterogeneous Types of miRNA-Disease Associations Stratified by Multi-Layer Network Embedding and Prediction

Abnormal miRNA functions are widely involved in many diseases recorded in the database of experimentally supported human miRNA-disease associations (HMDD). Some of the associations are complicated: There can be up to five heterogeneous association types of miRNA with the same disease, including genetics type, epigenetics type, circulating miRNAs type, miRNA tissue expression type and miRNA-target interaction type. When one type of association is known for an miRNA-disease pair, it is important to predict any other types of the association for a better understanding of the disease mechanism. It is even more important to reveal associations for currently unassociated miRNAs and diseases. Methods have been recently proposed to make predictions on the association types of miRNA-disease pairs through restricted Boltzman machines, label propagation theories and tensor completion algorithms. None of them has exploited the non-linear characteristics in the miRNA-disease association network to improve the performance. We propose to use attributed multi-layer heterogeneous network embedding to learn the latent representations of miRNAs and diseases from each association type and then to predict the existence of the association type for all the miRNA-disease pairs. The performance of our method is compared with two newest methods via 10-fold cross-validation on the database HMDD v3.2 to demonstrate the superior prediction achieved by our method under different settings. Moreover, our real predictions made beyond the HMDD database can be all validated by NCBI literatures, confirming that our method is capable of accurately predicting new associations of miRNAs with diseases and their association types as well.

MicroRNA mediated therapeutic effects of natural agents in prostate cancer

BACKGROUND

Several natural products, extensively studied for their anticancer activities, have been found to play an efficient role in preventing prostate cancer (PCa). Recently many natural agents have been reported to modulate microRNAs (miRNAs), that are involved in cancer cell growth. The microRNAs are endogenous small noncoding ribonucleic acid molecules that regulate various biological processes through an elegant mechanism of post-transcriptional control of gene expression. Besides being involved in cancer initiation, progression, angiogenesis, inflammation, they have been reported to be responsible for chemoresistance, and radioresistance of tumors. The dysregulated miRNA expression has been associated with many cancers including PCa. Over the past several years, it has been found that natural agents are good regulators of miRNAs and have a role in PCa also. Understanding the molecular mechanisms involving miRNAs by natural agents could result in developing useful strategies to combat this deadly disease.

METHODS

In order to collect research articles, the PubMed search engine was used with keywords 'prostate cancer' and 'natural agents' and 2007 papers were retrieved, further refinement with keywords 'phytochemical' and 'prostate cancer' showed 503 papers. Data was collected from research articles, published from 2010 to 2021. From these, research articles showing miRNA-mediated mechanisms were selected.

RESULTS

In this review, we have summarized the information available on the modulation of miRNAs by natural agents, their derivatives, and various combinatorial strategies with chemo/radiation therapy for the mitigation of PCa.

CONCLUSIONS

Based on the current review of literature, it has been found that the use of natural agents is a novel approach for altering miRNA expression strongly associated with PCa development, recurrence and resistance.

Global investigation of estrogen-responsive genes regulating lipid metabolism in the liver of laying hens

BACKGROUND

Estrogen plays an essential role in female development and reproductive function. In chickens, estrogen is critical for lipid metabolism in the liver. The regulatory molecular network of estrogen in chicken liver is poorly understood. To identify estrogen-responsive genes and estrogen functional sites on a genome-wide scale, we determined expression profiles of mRNAs, lncRNAs, and miRNAs in estrogen-treated ((17β-estradiol)) and control chicken livers using RNA-Sequencing (RNA-Seq) and studied the estrogen receptor α binding sites by ChIP-Sequencing (ChIP-Seq).

RESULTS

We identified a total of 990 estrogen-responsive genes, including 962 protein-coding genes, 11 miRNAs, and 17 lncRNAs. Functional enrichment analyses showed that the estrogen-responsive genes were highly enriched in lipid metabolism and biological processes. Integrated analysis of the data of RNA-Seq and ChIP-Seq, identified 191 genes directly targeted by estrogen, including 185 protein-coding genes, 4 miRNAs, and 2 lncRNAs. In vivo and in vitro experiments showed that estrogen decreased the mRNA expression of PPARGC1B, which had been reported to be linked with lipid metabolism, by directly increasing the expression of miR-144-3p.

CONCLUSIONS

These results increase our understanding of the functional network of estrogen in chicken liver and also reveal aspects of the molecular mechanism of estrogen-related lipid metabolism.

Role of noncoding RNA in drug resistance of prostate cancer

Prostate cancer is one of the most prevalent forms of cancer around the world. Androgen-deprivation treatment and chemotherapy are the curative approaches used to suppress prostate cancer progression. However, drug resistance is extensively and hard to overcome even though remarkable progress has been made in recent decades. Noncoding RNAs, such as miRNAs, lncRNAs, and circRNAs, are a group of cellular RNAs which participate in various cellular processes and diseases. Recently, accumulating evidence has highlighted the vital role of non-coding RNA in the development of drug resistance in prostate cancer. In this review, we summarize the important roles of these three classes of noncoding RNA in drug resistance and the potential therapeutic applications in this disease.

Micro RNA-148a Targets Bcl-2 in Patients with Non-Small Cell Lung Cancer

OBJECTIVE

Lung cancer is one of the most prevalent cancers and the leading cause of cancer-related deaths worldwide. MicroRNAs regulate more than 60% of human genes, including tumor suppressor genes and oncogenes. Accordingly, they can affect cancer risk. This study aimed to evaluate the role of serum miR-148a as a non-invasive biomarker in non-small cell lung cancer (NSCLC) patients and to assess the correlation between miR-148a and Bcl-2, as one of its target proteins.

MATERIALS AND METHODS

A total of 50 newly diagnosed NSCLC cases and 30 apparently healthy controls were recruited in this study. MiR-148a level was measured by TaqMan- Real time RT-PCR assay and Bcl-2 level was measured by ELISA.

RESULTS

Significant lower expression of serum miR-148a and higher serum Bcl-2 levels were observed in NSCLC patients as compared to the control group (p.

miRNA as Regulators of Prostate Carcinogenesis and Endocrine and Chemoresistance

More therapy options are available for advanced prostate cancer, including novel inhibitors of androgen synthesis, anti-androgens, chemotherapeutics and targeted therapies. Although patients ´ survival has been improved, management of castration therapy-resistant prostate cancer remains a challenge. Regulation of cellular events in cancer by small non-coding miRNAs is, therefore, an area of special interest. Overexpression of selected miRNA may lead to androgen independence and prostate cancer progression. miRNA may be considered also a biomarker in patients with prostate cancer. In contrast, diminished expression of tumor-suppressive miRNA in prostate cancer leads to enhanced proliferation, reduced apoptosis, increased migration, invasion and epithelial- to-mesenchymal transition. miRNA may be directly involved in the regulation of chemosensitivity in prostate cancer. Experimental overexpression of selected miRNA in chemoresistant prostate cancer leads to the inhibition of cellular stemness and epithelial-to-mesenchymal transition. Reduction of tumor-suppressive miRNA may also lead to hyperactivity of signaling pathways such as that of the epidermal growth factor receptor and mitogen-activated protein kinase. Although considerable progress on miRNA research in prostate cancer has been achieved, therapeutic effects could be improved on the basis of the development of novel delivery methods.

MicroRNAs as Epigenetic Determinants of Treatment Response and Potential Therapeutic Targets in Prostate Cancer

Prostate cancer (PCa) is the second most common tumor in men worldwide, and the fifth leading cause of male cancer-related deaths in western countries. PC is a very heterogeneous disease, meaning that optimal clinical management of individual patients is challenging. Depending on disease grade and stage, patients can be followed in active surveillance protocols or undergo surgery, radiotherapy, hormonal therapy, and chemotherapy. Although therapeutic advancements exist in both radiatiotherapy and chemotherapy, in a considerable proportion of patients, the treatment remains unsuccessful, mainly due to tumor poor responsiveness and/or recurrence and metastasis. microRNAs (miRNAs), small noncoding RNAs that epigenetically regulate gene expression, are essential actors in multiple tumor-related processes, including apoptosis, cell growth and proliferation, autophagy, epithelial-to-mesenchymal transition, invasion, and metastasis. Given that these processes are deeply involved in cell response to anti-cancer treatments, miRNAs have been considered as key determinants of tumor treatment response. In this review, we provide an overview on main PCa-related miRNAs and describe the biological mechanisms by which specific miRNAs concur to determine PCa response to radiation and drug therapy. Additionally, we illustrate whether miRNAs can be considered novel therapeutic targets or tools on the basis of the consequences of their expression modulation in PCa experimental models.

Novel, non-invasive markers for detecting therapy induced neuroendocrine differentiation in castration-resistant prostate cancer patients

Neuroendocrine prostate cancer (NEPC), a highly aggressive variant of castration-resistant prostate cancer (CRPC), often emerges upon treatment with androgen pathway inhibitors, via neuroendocrine differentiation. Currently, NEPC diagnosis is challenging as available markers are not sufficiently specific. Our objective was to identify novel, extracellular vesicles (EV)-based biomarkers for diagnosing NEPC. Towards this, we performed small RNA next generation sequencing in serum EVs isolated from a cohort of CRPC patients with adenocarcinoma characteristics (CRPC-Adeno) vs CRPC-NE and identified significant dysregulation of 182 known and 4 novel miRNAs. We employed machine learning algorithms to develop an 'EV-miRNA classifier' that could robustly stratify 'CRPC-NE' from 'CRPC-Adeno'. Examination of protein repertoire of exosomes from NEPC cellular models by mass spectrometry identified thrombospondin 1 (TSP1) as a specific biomarker. In view of our results, we propose that a miRNA panel and TSP1 can be used as novel, non-invasive tools to identify NEPC and guide treatment decisions. In conclusion, our study identifies for the first time, novel non-invasive exosomal/extracellular vesicle based biomarkers for detecting neuroendocrine differentiation in advanced castration resistant prostate cancer patients with important translational implications in clinical management of these patients that is currently extremely challenging.

Androgen Receptor-Related Non-coding RNAs in Prostate Cancer

Prostate cancer (PCa) is the second leading cause of cancer-related death among men in the United States. Androgen receptor (AR) signaling is the dominant oncogenic pathway in PCa and the main strategy of PCa treatment is to control the AR activity. A large number of patients acquire resistance to Androgen deprivation therapy (ADT) due to AR aberrant activation, resulting in castration-resistant prostate cancer (CRPC). Understanding the molecular mechanisms underlying AR signaling in the PCa is critical to identify new therapeutic targets for PCa patients. The recent advances in high-throughput RNA sequencing (RNA-seq) techniques identified an increasing number of non-coding RNAs (ncRNAs) that play critical roles through various mechanisms in different diseases. Some ncRNAs have shown great potentials as biomarkers and therapeutic targets. Many ncRNAs have been investigated to regulate PCa through direct association with AR. In this review, we aim to comprehensively summarize recent findings of the functional roles and molecular mechanisms of AR-related ncRNAs as AR regulators or targets in the progression of PCa.

Flavonoid display ability to target microRNAs in cancer pathogenesis

MicroRNAs (miRNAs) are non-coding, conserved, single-stranded nucleotide sequences involved in physiological and developmental processes. Recent evidence suggests an association between miRNAs' deregulation with initiation, promotion, progression, and drug resistance in cancer cells. Besides, miRNAs are known to regulate the epithelial-mesenchymal transition, angiogenesis, autophagy, and senescence in different cancer types. Previous reports proposed that apart from the antioxidant potential, flavonoids play an essential role in miRNAs modulation associated with changes in cancer-related proteins, tumor suppressor genes, and oncogenes. Thus, flavonoids can suppress proliferation, help in the development of drug sensitivity, suppress metastasis and angiogenesis by modulating miRNAs expression. In the present review, we summarize the role of miRNAs in cancer, drug resistance, and the chemopreventive potential of flavonoids mediated by miRNAs. The potential of flavonoids to modulate miRNAs expression in different cancer types demonstrate their selectivity and importance as regulators of carcinogenesis. Flavonoids as chemopreventive agents targeting miRNAs are extensively studied in vitro, in vivo, and pre-clinical studies, but their efficiency in targeting miRNAs in clinical studies is less investigated. The evidence presented in this review highlights the potential of flavonoids in cancer prevention/treatment by regulating miRNAs, although further investigations are required to validate and establish their clinical usefulness.

Potential miRNA biomarkers for the diagnosis and prognosis of esophageal cancer detected by a novel absolute quantitative RT-qPCR method

miRNAs are expected to become potential biomarkers in the diagnosis and prognosis of Esophageal cancer (EC). Through a series of screening, miR-34a-5p, miR-148a-3p and miR-181a-5p were selected as EC-associated miRNAs. Based on AllGlo probe, a novel absolute quantitative RT-qPCR method with high sensitivity, specificity and accuracy was established for detecting miRNAs. Then the clinical significance of these 3 miRNAs was explored with 213 patients (166 cases with EC and 47 cases with benign diseases) and 170 normal controls. Compared with normal controls, the level of miR-34a-5p increased while miR-148a-3p and miR-181a-5p decreased in EC and benign patients (P < 0.001), and the level of miR-181a-5p in early EC patients was significantly lower (P < 0.001). According to logistic regression analysis, combined detection of miR-34a-5p, miR-148a-3p and Cyfra21-1 provided the highest diagnosis efficiency of 85.07% with sensitivity and specificity reaching 85.45% and 84.71%. Compared with preoperative samples, the level of miR-34a-5p decreased while miR-148a-3p and miR-181a-5p increased in postoperative samples (P < 0.001). Collectively, this first developed, novel absolute quantitative RT-qPCR method exhibits high application value in detecting miRNAs, miR-34a-5p, miR-148a-3p and miR-181a-5p may serve as potential biomarkers in the diagnosis and prognosis of EC, and miR-181a-5p probably could serve as a new biomarker for early EC.

Mechanisms of docetaxel resistance in prostate cancer: The key role played by miRNAs

One of the main problems with the treatment of metastatic prostate cancer is that, despite an initial positive response, the majority of patients develop resistance and progress. In particular, the resistance to docetaxel, the gold standard therapy for metastatic prostate cancer since 2010, represents one of the main factors responsible for the failure of prostate cancer therapy. According to the present knowledge, different processes contribute to the appearance of docetaxel resistance and non-coding RNA seems to play a relevant role in them. In this review, a comprehensive overview of the miRNA network involved in docetaxel resistance is described, highlighting the pathway/s affected by their activity.

miR-148a Regulates the Stem Cell-Like Side Populations Distribution by Affecting the Expression of ACVR1 in Esophageal Squamous Cell Carcinoma

Introduction

Esophageal squamous cell carcinoma (ESCC) is a malignant tumor disease with high mortality and morbidity rates, especially for a terminal cancer. At present, the prognosis and treatment of ESCC cannot effectively control or inhibit the spread and proliferation of tumor cells. microRNAs, a class of small spliced RNAs, are essential in the regulation of tumorigenesis and tumor cell migration and proliferation. microRNAs interact with target mRNA to silence gene expression and degrade mRNA, thereby inhibiting the expression of tumor genes or impairing the expression of tumor suppressor genes.

Methods

A total of 20 human ESCC samples were collected from the Affiliated Tumor Hospital of Xinjiang Medical University. Eca109 and Kyse510 cells, which are ESCC cell lines, were subjected to FACS analysis to get side population (SP) cells and non-SP cells. Cell cycle and cell proliferation were analyzed by flow cytometry. Cell migration and invasion were detected using a transwell assay. Quantitative PCR and Western blot were performed to analyze the expression levels of ABCG2, KLF4, OCT4, and ACVR1, which are related to the stemness of stem cells. The target genes of hsa-miR-148a were predicted using TargetScan (version 7.2) and verified by a dual luciferase reporter assay. A chromatin immunoprecipitation (ChIP) assay was carried out to demonstrate direct interaction between miR-148a and ACVR1.

Results

The expression of miR-148a was significantly down-regulated in ESCC cells and significantly decreased in SP esophageal squamous cells when compared to the tumor cells. By analyzing the stem cell stemness of ESCC, overexpression of miR-148a decreased the expression of ABCG2, KLF4, SOX2, OCT4, and Nanog, indicating that miR-148a may regulate stem cell function. Target gene prediction and functional annotation of miR-148a suggested that miR-148a is involved in stem cell stemness of ESCC via ACVR1. Expression of the dual luciferase-labeled gene indicates that overexpression of miR-148a inhibits the expression of ACVR1, thereby affecting stem cell stemness.

Conclusion

miR-148a regulates the stem cell-like side populations distribution by inhibiting the expression of ACVR1 in ESCC. miR-148a may be a promising targeted therapy for ESCC.

A Novel Predictor Tool of Biochemical Recurrence after Radical Prostatectomy Based on a Five-MicroRNA Tissue Signature

Within five to ten years after radical prostatectomy (RP), approximately 15–34% of prostate cancer (PCa) patients experience biochemical recurrence (BCR), which is defined as recurrence of serum levels of prostate-specific antigen >0.2 µg/L, indicating probable cancer recurrence. Models using clinicopathological variables for predicting this risk for patients lack accuracy. There is hope that new molecular biomarkers, like microRNAs (miRNAs), could be potential candidates to improve risk prediction. Therefore, we evaluated the BCR prognostic capability of 20 miRNAs, which were selected by a systematic literature review. MiRNA expressions were measured in formalin-fixed, paraffin-embedded (FFPE) tissue RP samples of 206 PCa patients by RT-qPCR. Univariate and multivariate Cox regression analyses were performed, to assess the independent prognostic potential of miRNAs. Internal validation was performed, using bootstrapping and the split-sample method. Five miRNAs (miR-30c-5p/31-5p/141-3p/148a-3p/miR-221-3p) were finally validated as independent prognostic biomarkers. Their prognostic ability and accuracy were evaluated using C-statistics of the obtained prognostic indices in the Cox regression, time-dependent receiver-operating characteristics, and decision curve analyses. Models of miRNAs, combined with relevant clinicopathological factors, were built. The five-miRNA-panel outperformed clinically established BCR scoring systems, while their combination significantly improved predictive power, based on clinicopathological factors alone. We conclude that this miRNA-based-predictor panel will be worth to be including in future studies.

Up-regulation of miRNA-148a inhibits proliferation, invasion, and migration while promoting apoptosis of cervical cancer cells by down-regulating RRS1

The purpose of the present study is to figure out the role of miRNA-148a (miR-148a) in growth, apoptosis, invasion, and migration of cervical cancer cells by binding to regulator of ribosome synthesis 1 (RRS1). Cervical cancer and adjacent normal tissues, as well as cervical cancer cell line Caski, HeLa, C-33A, and normal cervical epithelial cell line H8 were obtained to detect the expression of miR-148a and RRS1. Relationship between miR-148a and RRS1 expression with clinicopathological characteristics was assessed. The selected Caski and HeLa cells were then transfected with miR-148a mimics, miR-148a inhibitors or RRS1 siRNA to investigate the role of miR-148a and RRS1 on proliferation, apoptosis, colony formation, invasion, and migration abilities of cervical cancer cells. Bioinformatics information and dual luciferase reporter gene assay was for used to detect the targetting relationship between miR-148a and RRS1. Down-regulated miR-148a and up-regulated RRS1 were found in cervical cancer tissues and cells. Down-regulated miR-148a and up-regulated RRS1 are closely related with prognostic factors of cervical cancer. RRS1 was determined as a target gene of miR-148a and miR-148a inhibited RRS1 expression in cervical cancer cells. Up-regulation of miR-148a inhibited cell proliferation, migration, and invasion while promoting apoptosis in Caski and HeLa cells. Our study suggests that miR-148a down-regulates RRS1 expression, thereby inhibiting the proliferation, migration, and invasion while promoting cell apoptosis of cervical cancer cells.

MicroRNA‑302a upregulation mediates chemo‑resistance in prostate cancer cells

MicroRNAs (miRNAs) are post‑transcriptional regulators that mediate the initiation and progression of human cancer. Growing evidence suggests that deregulation of miRNA expression levels underlies chemo‑resistance. To investigate whether miRNA‑302a (miR‑302a) is involved in mediating chemo‑resistance to paclitaxel in prostate cancer, a series of in vitro analyses were performed in paclitaxel‑resistant prostate cancer PC‑3PR cells and non‑resistant prostate cancer PC‑3 cells. It was demonstrated that the expression of miR‑302a was upregulated in PC‑3PR cells. Notably, ectopic expression of miR‑302a also increased resistance to paclitaxel in wild‑type PC‑3 cells. By contrast, silencing of miR‑302a in PC‑3PR cells sensitized the cells to paclitaxel. Gene and protein expression analyses suggested that the miR‑302a target gene breast cancer resistance protein (BCRP) may mediate chemo‑resistance to paclitaxel in PC‑3PR cells. In conclusion, the data suggested that elevated miR‑302a levels, in part, mediate sensitivity to paclitaxel in prostate cancer through the aberrant regulation of its downstream targets, AOF2, BCRP and permeability glycoprotein 1. These data have implications for the development of novel therapeutics in prostate cancer that may improve sensitivity to chemotherapeutics.

The role and mechanisms of action of microRNAs in cancer drug resistance

MicroRNAs (miRNAs) are small non-coding RNAs with a length of about 19–25 nt, which can regulate various target genes and are thus involved in the regulation of a variety of biological and pathological processes, including the formation and development of cancer. Drug resistance in cancer chemotherapy is one of the main obstacles to curing this malignant disease. Statistical data indicate that over 90% of the mortality of patients with cancer is related to drug resistance. Drug resistance of cancer chemotherapy can be caused by many mechanisms, such as decreased antitumor drug uptake, modified drug targets, altered cell cycle checkpoints, or increased DNA damage repair, among others. In recent years, many studies have shown that miRNAs are involved in the drug resistance of tumor cells by targeting drug-resistance-related genes or influencing genes related to cell proliferation, cell cycle, and apoptosis. A single miRNA often targets a number of genes, and its regulatory effect is tissue-specific. In this review, we emphasize the miRNAs that are involved in the regulation of drug resistance among different cancers and probe the mechanisms of the deregulated expression of miRNAs. The molecular targets of miRNAs and their underlying signaling pathways are also explored comprehensively. A holistic understanding of the functions of miRNAs in drug resistance will help us develop better strategies to regulate them efficiently and will finally pave the way toward better translation of miRNAs into clinics, developing them into a promising approach in cancer therapy.

miR-148a regulates expression of the transferrin receptor 1 in hepatocellular carcinoma

Transferrin receptor 1 (TFR1) is a transmembrane glycoprotein that allows for transferrin-bound iron uptake in mammalian cells. It is overexpressed in various cancers to satisfy the high iron demand of fast proliferating cells. Here we show that in hepatocellular carcinoma (HCC) TFR1 expression is regulated by miR-148a. Within the TFR1 3′UTR we identified and experimentally validated two evolutionarily conserved miRNA response elements (MREs) for miR-148/152 family members, including miR-148a. Interestingly, analyses of RNA sequencing data from patients with liver hepatocellular carcinoma (LIHC) revealed a significant inverse correlation of TFR1 mRNA levels and miR-148a. In addition, TFR1 mRNA levels were significantly increased in the tumor compared to matched normal healthy tissue, while miR-148a levels are decreased. Functional analysis demonstrated post-transcriptional regulation of TFR1 by miR-148a in HCC cells as well as decreased HCC cell proliferation upon either miR-148a overexpression or TFR1 knockdown. We hypothesize that decreased expression of miR-148a in HCC may elevate transferrin-bound iron uptake, increasing cellular iron levels and cell proliferation.

Preliminary study on the role of miR‑148a and DNMT1 in the pathogenesis of acute myeloid leukemia

MicroRNA (miR)‑148a is differentially expressed in numerous malignant tumors and it was identified to regulate tumor growth, cell proliferation, apoptosis, angiogenesis and drug resistance via the regulation of the expression levels of its target genes. However, the biological function of miR‑148a in acute myeloid leukemia (AML) and its molecular mechanisms of action remain unclear. In the present study, the expression levels of miR‑148a and DNA methyltransferase 1 (DNMT1) were detected using reverse transcription‑quantitative polymerase chain reaction (PCR) and western blotting. Methylation‑specific PCR was used to detect the methylation levels in the miR‑148a promoter. The effects of miR‑148a on cell proliferation and apoptosis were assessed by Cell Counting kit‑8 or flow cytometry assays, respectively. A dual‑luciferase reporter assay was performed to investigate the association between miR‑148a and DNMT1. Patients with AML exhibited an increased expression level of miR‑148a, whereas the expression level of DNMT1 was identified to be decreased compared with healthy control subjects. In AML cell lines, the methylation state of miR‑148 promoter was significantly increased compared with normal cells. Following knockdown of DNMT1 in U937 cells, the expression level of miR‑148a increased significantly, whereas the methylation level of the miR‑148a promoter decreased. The mRNA and protein expression levels of DNMT1 decreased following transfection with miR‑148a mimics in U937 cells. Conversely, transfection with miR‑148a inhibitor in Kasumi‑1 cells led to an increase in the expression level of DNMT. Dual‑luciferase reporter assays suggested that DNMT1 was one of the direct target genes of miR‑148a. Overexpression of miR‑148a inhibited cell proliferation and promoted apoptosis. Inhibition of DNMT1 led to a decreased methylation level of the 5'‑cytosine‑phosphate‑guanine‑3' islands in the miR‑148a promoter, thus increasing the expression level of miR‑148a. DNMT1 was identified to be a downstream target of miR‑148a, and was negatively regulated by miR‑148a in AML cell lines, suggesting that miR‑148a and DNMT1 form a mutual negative feedback loop.

Application of Prostate Cancer Models for Preclinical Study: Advantages and Limitations of Cell Lines, Patient-Derived Xenografts, and Three-Dimensional Culture of Patient-Derived Cells

Various preclinical models have been developed to clarify the pathophysiology of prostate cancer (PCa). Traditional PCa cell lines from clinical metastatic lesions, as exemplified by DU-145, PC-3, and LNCaP cells, are useful tools to define mechanisms underlying tumorigenesis and drug resistance. Cell line-based experiments, however, have limitations for preclinical studies because those cells are basically adapted to 2-dimensional monolayer culture conditions, in which the majority of primary PCa cells cannot survive. Recent tissue engineering enables generation of PCa patient-derived xenografts (PDXs) from both primary and metastatic lesions. Compared with fresh PCa tissue transplantation in athymic mice, co-injection of PCa tissues with extracellular matrix in highly immunodeficient mice has remarkably improved the success rate of PDX generation. PDX models have advantages to appropriately recapitulate the molecular diversity, cellular heterogeneity, and histology of original patient tumors. In contrast to PDX models, patient-derived organoid and spheroid PCa models in 3-dimensional culture are more feasible tools for in vitro studies for retaining the characteristics of patient tumors. In this article, we review PCa preclinical model cell lines and their sublines, PDXs, and patient-derived organoid and spheroid models. These PCa models will be applied to the development of new strategies for cancer precision medicine.

Long non-coding RNA CCAT1/miR-148a/PKCζ prevents cell migration of prostate cancer by altering macrophage polarization

BACKGROUND

Macrophage polarization plays an important role in tumor microenvironment, which regulated the prognosis of prostate cancer. However, the potential role of it is still need further identification.

METHODS

The M1 Macrophages were inducted using 100 ng/mL LPS and 100 ng/mL IFN-γ, the M1 Macrophages were inducted using 20 ng/mL IL-4. TAMs were obtained by culturing monocytes for 7 days in RPMI 1640 10% FBS with 50% of conditioned medium from PC-3 cells real-time PCR was performed to determine the expression of miR-148a, CCAT1, and PKCζ. Western blot was used to measure the level of PKCζ. The cytokine IL-10 was determined using ELISA. Transwell chamber was carried out to determine cell migration. Luciferase reporter assay was used to determine the relationship between miR-148a and PKCζ.

RESULTS

The expression of miR-148a was highest in TAMs, while CCAT1 and PKCζ were highest in M1 Macrophages. Overexpressed miR-148a promoted the level of IL-10 and cell migration. Down-regulated CCAT1 promoted the level of IL-10 and cell migration, while this effects were abolished by co-transfection of si-CCAT1 and miR-148a inhibitor. PKCζ is the target gene of miR-148a. The effects of overexpressed miR-148a on the level of IL-10, genes expression, and cell migration were abolished by miR-148a mimic and pcDNA-PKCζ. In vivo experiments verified the effects of CCAT1 and miR-148a on tumor growth.

CONCLUSION

CCAT1 knockdown promoted M2 macrophages polarization by up-regulating miR-148a, while miR-148a up-regulation promoted M2 macrophages polarization by down-regulating the expression of PKCζ.

Complex role of miR-130a-3p and miR-148a-3p balance on drug resistance and tumor biology in esophageal squamous cell carcinoma

miRNAs play a crucial role in cancer development and progression. However, results on the impact of miRNAs on drug sensitivity and tumor biology vary, and most studies to date focussed on either increasing or decreasing miRNA expression levels. Therefore, the current study investigated the role of different expression levels of miR-130a-3p and miR-148a-3p on drug resistance and tumor biology in four esophageal squamous cell carcinoma cell lines. Interestingly, up- and downregulation of both miRNAs significantly increased sensitivity towards chemotherapy. MiRNA modulation also reduced adherence and migration potential, and increased apoptosis rates. Target analyses showed that up- and downregulation of both miRNAs activated the apoptotic p53-pathway via increased expression of either BAX (miR-148a-3p) or Caspase 9 (miR-130a-3p). miR-148a-3p downregulation seemed to mediate its effects primarily via regulation of Bim rather than Bcl-2 levels, whereas we found the opposite scenario following miR-148a-3p upregulation. A similar effect was observed for miR-130a-3p regulating Bcl-2 and XIAP. Our data provide the first evidence that miRNA modulation in both directions may lead to similar effects on chemotherapy response and tumor biology in esophageal squamous cell carcinoma. Most interestingly, up- and downregulation seem to mediate their effects via modulating the balance of several validated or predicted targets.

Prostate cancer tends to metastasize in the bone-mimicking microenvironment via activating NF-κB signaling

Prostate cancer preferentially metastasizes to the bone. However, the underlying molecular mechanisms are still unclear. To explore the effects of a bone-mimicking microenvironment on PC3 prostate cancer cell growth and metastasis, we used osteoblast differentiation medium (ODM; minimal essential medium alpha supplemented with L-ascorbic acid) to mimic the bone microenvironment. PC3 cells grown in ODM underwent epithelial-mesenchymal transition and showed enhanced colony formation, migration, and invasion abilities compared to the cells grown in normal medium. PC3 cells grown in ODM showed enhanced metastasis when injected in mice. A screening of signaling pathways related to invasion and metastasis revealed that the NF-κB pathway was activated, which could be reversed by Bay 11-7082, a NF-κB pathway inhibitor. These results indicate that the cells in different culture conditions manifested significantly different biological behaviors and the NF-κB pathway is a potential therapeutic target for prostate cancer bone metastasis.

MiR-616-3p modulates cell proliferation and migration through targeting tissue factor pathway inhibitor 2 in preeclampsia

OBJECTIVES

Despite improvements in diagnosis and treatment, preeclampsia (PE) continues to pose a significant risk of maternal and foetal morbidity and mortality if not addressed promptly. An increasing number of studies have suggested that tissue factor pathway inhibitor 2 (TFPI2) acts as a suppressor gene, possibly inhibiting multiple serine proteases affecting cell proliferation and migration. It plays an essential role in the occurrence and development of PE, but the pathogenesis remains unclear.

MATERIALS AND METHODS

In our research, we performed western blotting, immunohistochemistry and qPCR assays to investigate TFPI2 and miR-616-3p expression in preeclamptic placental tissues. Cell assays were performed in HTR-8/SVneo and JEG3 cell lines. Cell proliferation and migration events were investigated by MTT, EdU and transwell assays. In conjunction with bioinformatics analysis, luciferase reporter assays were performed to elucidate the mechanism by which miR-616-3p binds to TFPI2 mRNA.

RESULTS

We established that TFPI2 protein levels were significantly upregulated in PE placental tissues. In addition, we found that miR-616-3p binds specifically to the 3'-UTR region of TFPI2 mRNA. Furthermore, miR-616-3p knockdown or TFPI2 overexpression substantially impaired cell growth and migration, whereas miR-616-3p upregulation or TFPI2 knockdown stimulated cell proliferation and migration. This miR-616-3p/TFPI2 axis was also found to affect the epithelial-mesenchymal transition process in PE.

CONCLUSIONS

Our results demonstrated that TFPI2 plays a vital role in the progression of PE and might provide a prospective therapeutic strategy to mitigate the severity of the disorder.