Effects of miR-200c on the migration and invasion abilities of human prostate cancer Du145 cells and the corresponding mechanism

Prostate cancer: Novel genetic and immunologic biomarkers

Prostate cancer (PCa) is considered one of the most prevalent male malignancies worldwide with a global burden estimated to increase over the next two decades. Due to significant mortality and debilitation of survival, early diagnosis has been described as key. Unfortunately, current diagnostic serum-based strategies have low specificity and sensitivity. Histologic examination is invasive and not useful for treatment and monitoring purposes. Hence, a plethora of studies have been conducted to identify and validate an efficient noninvasive approach in the diagnosis, staging, and prognosis of PCa. These investigations may be categorized as genetic (non-coding biomarkers and gene markers), immunologic (immune cells, interleukins, cytokines, antibodies, and auto-antibodies), and heterogenous (PSA-related markers, PHI-related indices, and urinary biomarkers) subgroups. This review examines current approaches and potential strategies using biomarker panels in PCa.

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.

The role of miR-200 family in the regulation of hallmarks of cancer

MiRNAs are short non-coding RNAs that regulate gene expression post-transcriptionally contributing to the development of different diseases including cancer. The miR-200 family consists of five members, miR-200a, miR-200b, miR-200c, miR-141, and miR-429. Their expression is dysregulated in cancer tissue and their level is altered in the body fluids of cancer patients. Moreover, the levels of miR-200 family members correlate with clinical parameters such as cancer patients' survival which makes them potentially useful as diagnostic and prognostic biomarkers. MiRNAs can act as either oncomiRs or tumor suppressor miRNAs depending on the target genes and their role in the regulation of key oncogenic signaling pathways. In most types of cancer, the miR-200 family acts as tumor suppressor miRNA and regulates all features of cancer. In this review, we summarized the expression pattern of the miR-200 family in different types of cancer and their potential utility as biomarkers. Moreover, we comprehensively described the role of miR-200 family members in the regulation of all hallmarks of cancer proposed by Hanahan and Weinberg with the focus on the epithelial-mesenchymal transition, invasiveness, and metastasis of tumor cells.

miRNA-214-5p inhibits prostate cancer cell proliferation by targeting SOX4

Background

Prostate cancer is the most common malignant tumor in men. Due to the lack of theoretical research on its pathogenic mechanism, the current cure rate is still low. miRNAs play an important role in the pathogenesis of various cancers. miRNA-214-5p plays an important role in the development of a variety of cancers. This study aims to explore the expression level of miR-214-5p in prostate cancer and make a preliminary study of its molecular mechanism in the development of prostate cancer to provide effective new strategies for the treatment of prostate cancer.

Methods

The target genes of miRNA-214-5p were predicted with bioinformatics technology, and the target relationship between miRNA-214-5p and its target genes was verified with dual luciferase reporter assay. RT-qPCR and Western blot were used to detect the expression levels of miRNA-214-5p and target genes in 50 clinical samples and two common prostate continuous cell lines, respectively. The targeting relationship between miRNA-214-5p and its target genes was verified with clinical data. miRNA-214-5p and miRNA-214-5p inhibitor was over-expressed in DU-145 cell lines to verify the effect of miRNA-214-5p on prostate cancer cell proliferation and SOX4 gene expression. And the mechanism of miRNA-214-5p inhibiting the proliferation of prostate cancer cells were analyzed by detecting the expression difference of downstream factors of SOX4 pathway. Bioinformatics analysis showed that miRNA-214-5p combined with SOX4 3′UTR region, and dual luciferase reporter assay further verified the reliability of the predicted results. The low expression of miRNA-214-5p was observed in prostate cancer tissues and cells, while high expression of SOX4 was observed in prostate cancer tissues and cells.

Results

Overexpression of miRNA-214-5p to prostate cancer cells significantly inhibited the proliferation of cancer cells, and the expression of SOX4 was inhibited in the transfected cell line. After transfection of miRNA-214-5p inhibitor into prostate cancer cells, the cell proliferation rate further increased. Meanwhile, overexpression of miRNA-214-5p effectively inhibited the expression of SOX4 downstream factors, including c-Myc, eIF4E, and CDK4. However, the specific knockdown of SOX4 through SOX4 shRNA significantly reduced the proliferation of prostate cancer cell lines.

Conclusions

miRNA-214-5 can inhibit the proliferation of prostate cancer cells by specifically targeting S0X4 and inhibiting the expression of growth factors downstream of this pathway.

1. Low expression of miRNA-214-5p is observed in prostate cancer cells.

2. miRNA-214-5p inhibits the proliferation of prostate cancer cells in vitro by targeting SOX4.

Role of Metastasis-Related microRNAs in Prostate Cancer Progression and Treatment

Simple Summary

In this review article we summarize the current literature on the pro- and anti-metastatic roles of distinct microRNAs in prostate cancer with a particular focus on their impact on invasion, migration and epithelial-to-mesenchymal transition. Moreover, we give a brief overview on how this knowledge developed so far into novel therapeutic approaches to target metastatic prostate cancer.

Abstract

Prostate cancer (PCa) is one of the most prevalent cancer types in males and the consequences of its distant metastatic deposits are the leading cause of PCa mortality. Therefore, identifying the causes and molecular mechanisms of hematogenous metastasis formation is of considerable clinical importance for the future development of improved therapeutic approaches. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at the post-transcriptional level by targeting messenger RNAs. Numerous studies have identified miRNAs as promotors or inhibitors of metastasis and revealed, in part, their targeting pathways in PCa. Because miRNAs are remarkably stable and can be detected in both tissue and body fluid, its potential as specific biomarkers for metastasis and therapeutic response is also currently under preclinical evaluation. In the present review, we focus on miRNAs that are supposed to initiate or suppress metastasis by targeting several key mRNAs in PCa. Metastasis-suppressing miRNAs include miR-33a-5p, miR-34, miR-132 and miR-212, miR-145, the miR-200 family (incl. miR-141-3p), miR-204-5p, miR-532-3p, miR-335, miR-543, miR-505-3p, miR 19a 3p, miR-802, miR-940, and miR-3622a. Metastasis-promoting RNAs, such as miR-9, miR-181a, miR-210-3, miR-454, miR-671-5p, have been shown to increase the metastatic potential of PCa cells. Other metastasis-related miRNAs with conflicting reports in the literature are also discussed (miR-21 and miR-186). Finally, we summarize the recent developments of miRNA-based therapeutic approaches, as well as current limitations in PCa. Taken together, the metastasis-controlling miRNAs provide the potential to be integrated in the strategy of diagnosis, prognosis, and treatment of metastatic PCa. Nevertheless, there is still a lack of consistency between certain miRNA signatures and reproducibility, which impedes clinical implementation.

Silencing FAM135B enhances radiosensitivity of esophageal carcinoma cell

FAM135B (family with sequence similarity 135, member B) is related to the progression of esophageal squamous cell carcinoma (ESCC). However, the role played by the gene in radiosensitivity remains unknown. Herein, we examined the relationship between FAM135B and radiosensitivity. According to the results, FAM135B is highly expressed in ESCC cells, and ESCC cells with high levels of FAM135B are resistant to irradiation. Silencing FAM135B inhibits colony formation capability and cell cycle protein expression (pP53, CDK1), promotes cell cycle arrest at the G2/M phase following irradiation. Moreover, transcriptome sequencing analysis demonstrates that FAM135B regulates downstream PI3K/Akt/mTOR signaling pathway, and western blot verifies the result. One of the mechanisms of increasing radiosensitivity by silencing FAM135B expression in ESCC cells may be achieved by regulating the PI3K/Akt/mTOR signaling pathway. Silencing FAM135B shows synergy with PI3K/Akt/mTOR pathway inhibitor (rapamycin) in increasing radiosensitivity, regulating the expression of cell cycle protein and inducing apoptosis of ESCC cells. The results indicate that FAM135B could be a potential treatment target for ESCC in management of radiosensitivity.

MicroRNAs in treatment-induced neuroendocrine differentiation in prostate cancer

Prostate cancer is a condition commonly associated with men worldwide. Androgen deprivation therapy remains one of the targeted therapies. However, after some years, there is biochemical recurrence and metastatic progression into castration-resistant prostate cancer (CRPC). CRPC cases are treated with second-line androgen deprivation therapy, after which, these CRPCs transdifferentiate to form neuroendocrine prostate cancer (NEPC), a highly aggressive variant of CRPC. NEPC arises via a reversible transdifferentiation process, known as neuroendocrine differentiation (NED), which is associated with altered expression of lineage markers such as decreased expression of androgen receptor and increased expression of neuroendocrine lineage markers including enolase 2, chromogranin A and synaptophysin. The etiological factors and molecular basis for NED are poorly understood, contributing to a lack of adequate molecular biomarkers for its diagnosis and therapy. Therefore, there is a need to fully understand the underlying molecular basis for this cancer. Recent studies have shown that microRNAs (miRNAs) play a key epigenetic role in driving therapy-induced NED in prostate cancer. In this review, we briefly describe the role of miRNAs in prostate cancer and CRPCs, discuss some key players in NEPCs and elaborate on miRNA dysregulation as a key epigenetic process that accompanies therapy-induced NED in metastatic CRPC. This understanding will contribute to better clinical management of the disease.

MicroRNAs as Guardians of the Prostate: Those Who Stand before Cancer. What Do We Really Know about the Role of microRNAs in Prostate Biology?

Prostate cancer is the second leading cause of cancer-related deaths of men in the Western world. Despite recent advancement in genomics, transcriptomics and proteomics to understand prostate cancer biology and disease progression, castration resistant metastatic prostate cancer remains a major clinical challenge and often becomes incurable. MicroRNAs (miRNAs), about 22-nucleotide-long non-coding RNAs, are a group of regulatory molecules that mainly work through post-transcriptional gene silencing via translational repression. Expression analysis studies have revealed that miRNAs are aberrantly expressed in cancers and have been recognized as regulators of prostate cancer progression. In this critical review, we provide an analysis of reported miRNA functions and conflicting studies as they relate to expression levels of specific miRNAs and prostate cancer progression; oncogenic and/or tumor suppressor roles; androgen receptor signaling; epithelial plasticity; and the current status of diagnostic and therapeutic applications. This review focuses on select miRNAs, highly expressed in normal and cancer tissue, to emphasize the current obstacles faced in utilizing miRNA data for significant impacts on prostate cancer therapeutics.

Urine miR-21-5p and miR-200c-3p as potential non-invasive biomarkers in patients with prostate cancer

OBJECTIVE

To evaluate the miR-21-5p and miR-200c-3p expressions in the urine of patients with prostate cancer (PCa) and to investigate their potential as biomarkers.

MATERIAL AND METHODS

The urine samples collected from 80 patients, including 20 patients diagnosed with benign prostate hyperplasia (BPH) and 60 patients diagnosed with PCa, were examined. The exosome isolation was performed using the miRCURY exosome isolation kit (Exiqon, Denmark), total RNA was extracted using the miRCURY RNA Isolation Kit-Biofluid kit (Exiqon, Denmark), and complementary DNA (cDNA) was synthesized using the Universal cDNA Synthesis kit (Exiqon, Denmark). A quantitative polymerase chain reaction (qPCR) analysis of gene expression was performed using the qPCR CFX 96 Thermocycler (Bio-Rad). All the procedures followed the manufacturer's recommendations.

RESULTS

The overexpressions of miR-21 in the non-metastatic PCa and metastatic PCa group compared to the BPH group were statistically significant with a p-value of 0.001 and 0.018, respectively. The non-metastatic PCa compared to the metastatic PCa group was also statistically significant with a p-value of 0.037. The under expressions of miR-200c in the non-metastatic PCa and metastatic PCa group compared to the BPH group are statistically significant with a p-value of 0.001 and 0.001, respectively.

CONCLUSION

The overexpressions of miR-21 found in this study could be a potential non-invasive diagnostic tool for patients with PCa. Despite the significant results in our study, the use of micro-RNA in urine samples may vary due to epigenetic variation. Further studies with larger populations are required to investigate the role of miR-21 and miR-200c as biomarkers in PCa.

Role of MicroRNAs in Treatment Response in Prostate Cancer

Prostate cancer (PCa) is the most common non-skin cancer in men worldwide, resulting in significant mortality and morbidity. Depending on the grade and stage of the cancer, patients may be given radiation therapy, hormonal therapy, or chemotherapy. However, more than half of these patients develop resistance to treatment, leading to disease progression and metastases, often with lethal consequences. MicroRNAs (miRNAs) are short, non-coding RNAs, which regulate numerous physiological as well as pathological processes, including cancer. miRNAs mediate their regulatory effect predominately by binding to the 3'-untranslated region (UTR) of their target mRNAs. In this review, we will describe the mechanisms by which miRNAs mediate resistance to radiation and drug therapy (i.e. hormone therapy and chemotherapy) in PCa, including control of apoptosis, cell growth and proliferation, autophagy, epithelial-to-mesenchymal transition (EMT), invasion and metastasis, and cancer stem cells (CSCs). Furthermore, we will discuss the utility of circulating miRNAs isolated from different body fluids of prostate cancer patients as non-invasive biomarkers of cancer detection, disease progression, and therapy response. Finally, we will shortlist the candidate miRNAs, which may have a role in drug and radioresistance, that could potentially be used as predictive biomarkers of treatment response.

MicroRNA-200c-3p/ZEB2 loop plays a crucial role in the tumor progression of prostate carcinoma

Background

The microRNA (miRNA) miR-200c-3p is involved in the tumorigenesis and progression of a variety of cancers. However, the underlying regulatory role of miR-200c-3p in prostate cancer (PCa) remains unclear.

Methods

Online databases including Oncomine, Linkedomics and StarBase were used to investigate the clinical significance of miR-200c-3p, along with associated gene targets. PCa tissues and adjacent normal tissues were used for the detection of miR-200c-3p expression. A lentivirus overexpressing miR-200c-3p was constructed and transfected into PC3 and DU145 cells. Cell formation of proliferation, migration, and invasion were determined by cell viability and colony-formation assay, wound healing assay, and Matrigel invasion assay, respectively. Epithelial-mesenchymal transition (EMT)-associated markers were determined by qRT-PCR and Western blot. A luciferase reporter assay was performed to determine the direct relationship of miR-200c-3p and ZEB2. The tumor-suppressive role of miR-200c-3p was further confirmed by a xenograft tumor model and immunohistochemical (IHC) staining.

Results

Online database analyses showed that miR-200c-3p was associated with pathologic T and N stage in PCa, and miR-200c-3p was downregulated in PCa tissues. Overexpression of miR-200c-3p was considered a tumor suppressor and was found to significantly suppress the formation of migration and invasion in PCa cells via repression of E-cadherin-induced EMT. The bioinformatic database indicated that ZEB2 has a significant correlation with miR-200c-3p and was upregulated in PCa tissues. Further, ZEB2 expression was suppressed by the upregulation of miR-200c-3p and was identified as a direct target of miR-200c-3p. In addition, repression of ZEB2 could restore the levels of miR-200c-3p in PCa cells in turn, suggesting a potential negative loop between miR-200c-3p and ZEB2. miR-200c-3p also had an antitumor effect by negatively regulating ZEB2 in a xenograft mouse model.

Conclusions

Taken together, the results of our study demonstrated the novel regulatory loop of miR-200c-3/ZEB2 in PCa progression, providing effective therapeutic strategies for PCa in the future.

USP14 de-ubiquitinates vimentin and miR-320a modulates USP14 and vimentin to contribute to malignancy in gastric cancer cells

Vimentin plays important roles in the epithelial-to-mesenchymal transition (EMT). In this study, we found that vimentin was highly expressed in human gastric cancer (GC) tissues and cell lines and significantly promoted cell growth, migration and invasion. Ubiquitin-specific protease 14 (USP14) interacted with the vimentin protein, which led to its de-ubiquitination. miR-320a was found to bind to the 3′UTR of both vimentin and USP14 transcripts and downregulate the expression of both proteins. The downregulation of miR-320a upregulates vimentin expression by directly binding to the 3′UTR of vimentin to derepress expression and indirectly by augmenting USP14 to increase vimentin stability in GC cells. Taken together, these results provide new insight into malignancy in gastric cancers.

MicroRNA-326 and microRNA-200c: Two novel biomarkers for diagnosis and prognosis of pediatric acute lymphoblastic leukemia

Multidrug resistance (MDR) is considered as the major obstacle for treating pediatric acute lymphoblastic leukemia (ALL). MicroRNAs (miRNAs) are small non coding RNAs which may potentially regulate response to chemotherapy. In this study, total RNA was isolated from bone marrow samples of 46 children with de novo ALL and 16 controls. Quantitative reverse transcriptase polymerase chain reaction was used to investigate the expression profile of the predicted miRNAs; miR-326 and miR-200c, and their predicted targets ABCA2, and ABCA3 transporters. The presence of minimal residual disease was studied using PCR-SSCP (single-strand conformation polymorphism) 1 year after treatment. The association between the miRNA expression and drug resistance was analyzed statistically. Results showed a significant down-regulation of both miR-326 and miR-200c expressions in ALL patients compared with non-cancer controls (P = 0.0002, AUC = 0.813 and P = 0.035, AUC = 0.79, respectively). A considerable negative association between miR-326 expression and MDR was identified which could raise the risk of chemoresistance by 4.8- fold. The expression profiles of miR-326 and ABCA2 transporter were inversely correlated. Data revealed, a novel diagnostic role for miR-326 and miR-200c as potential biomarkers of pediatric ALL. Down-regulation of miR-326 was introduced, for the first time, as a prognostic factor for drug resistance in childhood ALL. To the best of our knowledge, this is the first time that ABCA2 transporter is proposed as a target gene for miR-326, through which it can exert its impact on drug resistance. These data may provide novel approaches to new therapeutics and diagnostics.

GSE1 predicts poor survival outcome in gastric cancer patients by SLC7A5 enhancement of tumor growth and metastasis

Gastric cancer remains a malignancy with poor survival outcome. We herein report that GSE1, a proline-rich protein, possesses a role in the progression of human gastric cancer. The expression of GSE1 was observed to be much higher in human gastric cancer tissues compared with normal gastric tissues, and GSE1 expression correlated positively with lymph node metastasis, histological grade, depth of invasion, and clinical stage in gastric cancer patients. Moreover, GSE1 expression was also associated with decreased post-operative relapse-free survival and overall survival in the cohort. The forced expression of GSE1 in gastric cancer cell lines resulted in increased cell proliferation, increased colony formation, enhanced cell migration, and invasion. Furthermore, forced expression of GSE1 also increased tumor size and enhanced lung metastasis in xenograft models. The depletion of endogenous GSE1 with shRNAs decreased the oncogenicity and invasiveness of gastric cancer cells both in vitro and in vivo In addition, GSE1 was determined to be a direct target of miR-200b and miR-200c. Furthermore, GSE1 positively regulated the downstream gene SLC7A5 (also known as LAT-1), which was scanned and verified from mRNA sequencing. GSE1 therefore possesses an oncogenic role in human gastric cancer, and targeted therapeutic approaches to inhibit GSE1 function in gastric cancer warrant further consideration.

miRNA nanotherapeutics for cancer

MicroRNAs (miRNAs) are noncoding RNA molecules that regulate gene expression through diverse mechanisms. Increasing evidence suggests that miRNA-based therapies, either restoring or repressing miRNA expression and activity, hold great promise. However, the efficient delivery of miRNAs to target tissues is a major challenge in the transition of miRNA therapy to the clinic. Cationic polymers or viral vectors are efficient delivery agents but their systemic toxicity and immunogenicity limit their clinical usage. Efficient targeting and sustained release of miRNAs/anti-miRNAs using nanoparticles (NPs) conjugated with antibodies and/or peptides could reduce the required therapeutic dosage while minimizing systemic and cellular toxicity. Given their importance in clinical oncology, here we focus on the development of miRNA nanoformulations to achieve enhanced cellular uptake, bioavailability, and accumulation at the tumor site.

Demethylation drug 5-Aza-2'-deoxycytidine-induced upregulation of miR-200c inhibits the migration, invasion and epithelial-mesenchymal transition of clear cell renal cell carcinoma in vitro

The microRNA (miR)-200 family has been found to be involved in the process of mesenchymal-epithelial transition during renal development. Deregulation of miR-200c has been suggested to be involved in clear cell renal cell carcinoma (ccRCC). However, the precise role of miR-200c in the regulation of ccRCC metastasis has not been previously reported. In the present study, it was observed that miR-200c was frequently downregulated in ccRCC tissue compared with matched adjacent normal tissue. The expression of miR-200c was additionally reduced in ccRCC cell lines when compared with levels in normal renal cells. The DNA demethylation drug 5-Aza-2'-deoxycytidine (Aza) was used to treat several ccRCC cell lines, and it was observed that the expression of miR-200c was significantly increased following Aza treatment. Furthermore, treatment with Aza markedly inhibited ccRCC cell invasion and migration, while treatment with miR-200c inhibitor significantly enhanced invasion and migration of ccRCC cells. In addition, Aza treatment significantly promoted expression of E-cadherin and inhibited the expression of N-cadherin, while the inhibition of miR-200c downregulated E-cadherin and upregulated the expression of N-cadherin, suggesting that miR-200c has a suppressive role in epithelial-mesenchymal transition (EMT) of ccRCC cells. In conclusion, it was suggested that demethylation drug Aza-induced upregulation of miR-200c may inhibit migration, invasion and EMT in ccRCC cells.

Regulating Craniofacial Development at the 3' End: MicroRNAs and Their Function in Facial Morphogenesis

Defects in craniofacial development represent a majority of observed human birth defects, occurring at a rate as high as 1:800 live births. These defects often occur due to changes in neural crest cell (NCC) patterning and development and can affect non-NCC-derived structures due to interactions between NCCs and the surrounding cell types. Proper craniofacial development requires an intricate array of gene expression networks that are tightly controlled spatiotemporally by a number of regulatory mechanisms. One of these mechanisms involves the action of microRNAs (miRNAs), a class of noncoding RNAs that repress gene expression by binding to miRNA recognition sequences typically located in the 3' UTR of target mRNAs. Recent evidence illustrates that miRNAs are crucial for vertebrate facial morphogenesis, with changes in miRNA expression leading to facial birth defects, including some in complex human syndromes such as 22q11 (DiGeorge Syndrome). In this review, we highlight the current understanding of miRNA biogenesis, the roles of miRNAs in overall craniofacial development, the impact that loss of miRNAs has on normal development and the requirement for miRNAs in the development of specific craniofacial structures, including teeth. From these studies, it is clear that miRNAs are essential for normal facial development and morphogenesis, and a potential key in establishing new paradigms for repair and regeneration of facial defects.

Gene interference strategies as a new tool for the treatment of prostate cancer

Prostate cancer (PCa) is one of the most common cancer in men. It affects older men and the incidence increases with age; the median age at diagnosis is 67 years. The diagnosis of PCa is essentially based on three tools: digital rectal exam, serum concentration of prostate specific antigen, and transrectal ultrasound-guided biopsy. Currently, the therapeutic treatments of this cancer are different and range from the prostatectomy to hormonal therapy, to radiation therapy, to immunotherapy, and to chemotherapy. However, additional efforts are required in order to find new weapons for the treatment of metastatic setting of disease. The purpose of this review is to highlight new therapeutic strategies based on gene interference; in fact, numerous siRNA and miRNA in the therapeutic treatment of PCa are reported below.