MicroRNA profiling of novel African American and Caucasian Prostate Cancer cell lines reveals a reciprocal regulatory relationship of miR-152 and DNA methyltranferase 1

Diagnostic properties of miR-146a-5p from liquid biopsies in prostate cancer: A meta-analysis

BACKGROUND

Several studies on biomarker properties of microRNAs from liquid biopsy in prostate cancer (PCa) identified miR-146a-5p as a potential novel diagnostic marker. However, other studies with the same or similar topic failed to confirm the supposed discriminatory ability of miR-146a-5p, for which reason we aimed at elucidating the potential biomarker role of circulatory/urinary miR-146a-5p in PCa by conducting a qualitative and quantitative data synthesis.

METHODS

Eligible articles were identified by searching PubMed, Scopus and Web of Science databases. Open MetaAnalyst software was used for pooling data on sensitivity, specificity, likelihood ratio and diagnostic odds ratio (OR) of miR-146a-5p.

RESULTS

A total of 15 articles were eligible for qualitative data synthesis, while the results from 13 studies with 2080 participants were included in the meta-analysis. The established between-study heterogeneity was high, while the expression of hsa-miR-146a was associated with a diagnostic OR of 3.544 (P < 0.001; 95 %CI 2.186-5.747). Pooled sensitivity was found to be lower than 70 % (0.655, 95 %CI 0.573-0.729, P < 0.001), while the obtained value for specificity was 65 % (95 %CI 0.583-0.709, P < 0.001). Segregating studies according to ethnicity, sample type or the type of controls did not result in significantly higher sensitivity and specificity in subgroups, compared to the overall pooled data.

CONCLUSIONS

The resulting pooled sensitivity, specificity and diagnostic OR do not qualify miR-146a-5p for a reliable diagnostic biomarker of PCa.

Racial implications of time to surgery in disparities in thyroid cancer survival

INTRODUCTION

The influence of time to surgery on racial/ethnic disparities in papillary thyroid carcinoma (PTC) survival remains unstudied.

MATERIALS AND METHODS

The National Cancer Database (2004-2017) was queried for patients with localized PTC. Survival data was compared by time to surgery, patient demographics, and multivariable Cox regression was performed.

RESULTS

Of 126,708 patients included, 5% were Black, 10% Hispanic. Of all patients, 85% had no comorbidities. Non-Hispanic White (NHW) patients had a shorter median time to surgery than Black and Hispanic patients (36 vs. 43 vs. 42 days, respectively p ​< ​0.001). In multivariable analysis, longer time to surgery (>90 days vs ​< ​30 days) and Black race vs NHW, were associated with worse survival (HR: 1.56, (95%CI, 1.43-1.70), p ​< ​0.001 and HR: 1.21, (1.08-1.36), p ​= ​0.001), respectively.

CONCLUSION

Delaying surgery for thyroid cancer is associated with worse survival. However, independent of time to surgery and other confounders, there remains a disparity as black patients have poorer outcomes.

Tumor suppressive miR-99b-5p as an epigenomic regulator mediating mTOR/AR/SMARCD1 signaling axis in aggressive prostate cancer

Introduction

African American (AA) men exhibited 2.3-fold higher PCa incidence and 1.7-fold higher PCa mortality rates when compared to the European American (EA) men. Besides the socioeconomic factors, emerging evidence has highlighted that biological risk factors may play critical roles in the AA PCa disparities. Previously, we have shown that downregulated miR-99b-5p and upregulated mTOR cooperatively promotes the AA PCa aggressiveness and drug resistance.

Methods

In this study, we aimed to explore the miR-99b-5p/mTOR/AR/SMARCD1 signaling axis in AA PCa aggressiveness. The analyses used in the study included immunofluorescence, western blot, in-vitro functional assays (TUNEL, colony forming, and MTT), and chromatin immunoprecipitation (ChIP)-qPCR assays in 2D and/or 3D culture model of EA PCa and AA PCa cell lines.

Results

Specifically, the immunofluorescence staining, and western blot analysis has revealed that nuclear mTOR, AR, and SMARCD1 were highly expressed in AA PCa (MDA PCa 2b) compared to EA PCa (LNCaP) cell line. Western blot analysis further revealed that miR-99b-5p inhibited protein levels of mTOR, AR/AR-V7 and SMARCD1 in cytoplasm and nuclei of EA and AA PCa. The in-vitro functional (MTT, TUNEL, and clonogenic) assays have demonstrated that miR-99b-5p effectively inhibited cell proliferation/survival and induced cell apoptosis in EA and AA PCa cells. Moreover, combination of miR-99b-5p and enzalutamide (Enz) synergistically enhances the cytotoxicity against aggressive AA PCa and castration-resistant prostate cancer (CRPC). mTOR ChIP-qPCR assays further demonstrated that miR-99b-5p or miR-99b-5p/Enz significantly reduces the recruitment of mTOR to the genes involved in the metabolic reprogramming in CRPC.

Discussion

Taken together, miR-99b-5p may function as an epigenomic driver to modulate the mTOR/AR/SMARCD1 signaling axis in AA PCa and resistant CRPC.

Potential of miRNAs in Plasma Extracellular Vesicle for the Stratification of Prostate Cancer in a South African Population

Prostate cancer (PCa) is the most common cause of cancer death among African men. The analysis of microRNAs (miRNAs) in plasma extracellular vesicles (EVs) can be utilized as a non-invasive tool for the diagnosis of PCa. In this study, we used small RNA sequencing to profile miRNAs cargo in plasma EVs from South African PCa patients. We evaluated the differential expression of miRNAs between low and high Gleason scores in the plasma EVs of South African patients and in the prostatic tissue from data available in the Cancer Genome Atlas (TCGA) Data Portal. We identified 7 miRNAs differently expressed in both EVs and prostatic tissues. We evaluated their expression using qPCR in a larger cohort of 10 patients with benign prostatic hyperplasia (BPH) and 24 patients with PCa. Here, we reported that the ratio between two of these miRNAs (i.e., miR-194-5p/miR-16-5p) showed a higher concentration in PCa compared to BPH and in metastatic PCa compared to localized PCa. We explored for the first time the profiling of miRNAs cargo in plasma EVs as a tool for the identification of putative markers in the South African population. Our finding indicated the ratio miR-194-5p/miR-16-5p as a non-invasive marker for the evaluation of PCa aggressiveness in this population.

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.

Investigating miR-9 as a mediator in laryngeal cancer health disparities

Background

For several decades, Black patients have carried a higher burden of laryngeal cancer among all races. Even when accounting for sociodemographics, a disparity remains. Differentially expressed microRNAs have been linked to racially disparate clinical outcomes in breast and prostate cancers, yet an association in laryngeal cancer has not been addressed. In this study, we present our computational analysis of differentially expressed miRNAs in Black compared with White laryngeal cancer and further validate microRNA-9-5p (miR-9-5p) as a potential mediator of cancer phenotype and chemoresistance.

Methods

Bioinformatic analysis of 111 (92 Whites, 19 Black) laryngeal squamous cell carcinoma (LSCC) specimens from the TCGA revealed miRNAs were significantly differentially expressed in Black compared with White LSCC. We focused on miR-9-5 p which had a significant 4-fold lower expression in Black compared with White LSCC (p<0.05). After transient transfection with either miR-9 mimic or inhibitor in cell lines derived from Black (UM-SCC-12) or White LSCC patients (UM-SCC-10A), cellular migration and cell proliferation was assessed. Alterations in cisplatin sensitivity was evaluated in transient transfected cells via IC50 analysis. qPCR was performed on transfected cells to evaluate miR-9 targets and chemoresistance predictors, ABCC1 and MAP1B.

Results

Northern blot analysis revealed mature miR-9-5p was inherently lower in cell line UM-SCC-12 compared with UM-SCC-10A. UM -SCC-12 had baseline increase in cellular migration (p < 0.01), proliferation (p < 0.0001) and chemosensitivity (p < 0.01) compared to UM-SCC-10A. Increasing miR-9 in UM-SCC-12 cells resulted in decreased cellular migration (p < 0.05), decreased proliferation (p < 0.0001) and increased sensitivity to cisplatin (p < 0.001). Reducing miR-9 in UM-SCC-10A cells resulted in increased cellular migration (p < 0.05), increased proliferation (p < 0.05) and decreased sensitivity to cisplatin (p < 0.01). A significant inverse relationship in ABCC1 and MAP1B gene expression was observed when miR-9 levels were transiently elevated or reduced in either UM-SCC-12 or UM-SCC-10A cell lines, respectively, suggesting modulation by miR-9.

Conclusion

Collectively, these studies introduce differential miRNA expression in LSCC cancer health disparities and propose a role for low miR-9-5p as a mediator in LSCC tumorigenesis and chemoresistance.

Molecular Insight into Drug Resistance Mechanism Conferred by Aberrant PIK3CD Splice Variant in African American Prostate Cancer

Targeting PI3Kδ has emerged as a promising therapy for hematologic and non-hematologic malignancies. Previously, we identified an oncogenic splice variant, PIK3CD-S, conferring Idelalisib resistance in African American (AA) prostate cancer (PCa). In the current study, we employed a comprehensive analysis combining molecular biology, biochemistry, histology, in silico simulation, and in vitro functional assays to investigate the PIK3CD-S expression profiles in PCa samples and to elucidate the drug resistance mechanism mediated by PI3Kδ-S (encoded by PIK3CD-S). The immunohistochemistry, RT-PCR, and Western blot assays first confirmed that PI3Kδ-S is highly expressed in AA PCa. Compared with PCa expressing the full-length PI3Kδ-L, PCa expressing PI3Kδ-S exhibits enhanced drug resistance properties, including a higher cell viability, more antiapoptotic and invasive capacities, and constitutively activated PI3K/AKT signaling, in the presence of PI3Kδ/PI3K inhibitors (Idelalisib, Seletalisib, Wortmannin, and Dactolisib). Molecular docking, ATP-competitive assays, and PI3 kinase assays have further indicated a drastically reduced affinity of PI3Kδ inhibitors with PI3Kδ-S vs. PI3Kδ-L, attributed to the lack of core binding residues in the PI3Kδ-S catalytic domain. Additionally, SRSF2 has been identified as a critical splicing factor mediating exon 20 skipping in PIK3CD pre-mRNA. The inhibition of the SRSF2 activity by SRPIN340 successfully sensitizes AA PCa cells to PI3Kδ inhibitors, suggesting a novel therapeutic option for Idelalisib-resistant tumors.

mir152 hypomethylation as a mechanism for non-syndromic cleft lip and palate

Non-syndromic cleft lip with or without cleft palate (NSCLP), the most common human craniofacial malformation, is a complex disorder given its genetic heterogeneity and multifactorial component revealed by genetic, epidemiological, and epigenetic findings. Epigenetic variations associated with NSCLP have been identified; however, functional investigation has been limited. Here, we combined a reanalysis of NSCLP methylome data with genetic analysis and used both in vitro and in vivo approaches to dissect the functional effects of epigenetic changes. We found a region in mir152 that is frequently hypomethylated in NSCLP cohorts (21-26%), leading to mir152 overexpression. mir152 overexpression in human neural crest cells led to downregulation of spliceosomal, ribosomal, and adherens junction genes. In vivo analysis using zebrafish embryos revealed that mir152 upregulation leads to craniofacial cartilage impairment. Also, we suggest that zebrafish embryonic hypoxia leads to mir152 upregulation combined with mir152 hypomethylation and also analogous palatal alterations. We therefore propose that mir152 hypomethylation, potentially induced by hypoxia in early development, is a novel and frequent predisposing factor to NSCLP.

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.

Role of Precision Oncology in Type II Endometrial and Prostate Cancers in the African Population: Global Cancer Genomics Disparities

Precision oncology can be defined as molecular profiling of tumors to identify targetable alterations. Emerging research reports the high mortality rates associated with type II endometrial cancer in black women and with prostate cancer in men of African ancestry. The lack of adequate genetic reference information from the African genome is one of the major obstacles in exploring the benefits of precision oncology in the African context. Whilst external factors such as the geography, environment, health-care access and socio-economic status may contribute greatly towards the disparities observed in type II endometrial and prostate cancers in black populations compared to Caucasians, the contribution of African ancestry to the contribution of genetics to the etiology of these cancers cannot be ignored. Non-coding RNAs (ncRNAs) continue to emerge as important regulators of gene expression and the key molecular pathways involved in tumorigenesis. Particular attention is focused on activated/repressed genes and associated pathways, while the redundant pathways (pathways that have the same outcome or activate the same downstream effectors) are often ignored. However, comprehensive evidence to understand the relationship between type II endometrial cancer, prostate cancer and African ancestry remains poorly understood. The sub-Saharan African (SSA) region has both the highest incidence and mortality of both type II endometrial and prostate cancers. Understanding how the entire transcriptomic landscape of these two reproductive cancers is regulated by ncRNAs in an African cohort may help elucidate the relationship between race and pathological disparities of these two diseases. This review focuses on global disparities in medicine, PCa and ECa. The role of precision oncology in PCa and ECa in the African population will also be discussed.

Differential expression of microRNA between triple negative breast cancer patients of African American and European American descent

There are racial disparities in the outcome of triple negative breast cancer (TNBC) patients between women of African ancestry and women of European ancestry, even after accounting for lifestyle, socioeconomic and clinical factors. MicroRNA (miRNA) are non-coding molecules whose level of expression is associated with cancer suppression, proliferation and drug resistance; therefore, these have potential for biomarker applications in cancers including TNBC. Historically, miRNAs up-regulated in African American (AA) patients have received less attention than for patients of European ancestry. Using laser capture microdissection (LCM) to acquire ultrapure tumor cell samples, miRNA expression was evaluated in 15 AA and 15 European American (EA) TNBC patients. Tumor sections were evaluated using RNA extraction followed by miRNA analysis and profiling. Results were compared based on ethnicity and method of tissue fixation. miRNAs that showed high differential expression in AA TNBC patients compared to EA included: miR-19a, miR-192, miR-302a, miR-302b, miR-302c, miR-335, miR-520b, miR-520f and miR-645. LCM is a useful technique for isolation of tumor cells. We found a greater abundance of RNA in frozen samples compared to formalin fixed, paraffin embedded samples. miRNA appears to be a useful biomarker for TNBC to improve diagnosis and treatment.

Identification and Characterization of Key Differentially Expressed Genes Associated With Metronomic Dosing of Topotecan in Human Prostate Cancer

Repetitive, low-dose (metronomic; METRO) drug administration of some anticancer agents can overcome drug resistance and increase drug efficacy in many cancers, but the mechanisms are not understood fully. Previously, we showed that METRO dosing of topotecan (TOPO) is more effective than conventional (CONV) dosing in aggressive human prostate cancer (PCa) cell lines and in mouse tumor xenograft models. To gain mechanistic insights into METRO-TOPO activity, in this study we determined the effect of METRO- and CONV-TOPO treatment in a panel of human PCa cell lines representing castration-sensitive/resistant, androgen receptor (+/−), and those of different ethnicity on cell growth and gene expression. Differentially expressed genes (DEGs) were identified for METRO-TOPO therapy and compared to a PCa patient cohort and The Cancer Genome Atlas (TCGA) database. The top five DEGs were SERPINB5, CDKN1A, TNF, FOS, and ANGPT1. Ingenuity Pathway Analysis predicted several upstream regulators and identified top molecular networks associated with METRO dosing, including tumor suppression, anti-proliferation, angiogenesis, invasion, metastasis, and inflammation. Further, the top DEGs were associated with increase survival of PCa patients (TCGA database), as well as ethnic differences in gene expression patterns in patients and cell lines representing African Americans (AA) and European Americans (EA). Thus, we have identified candidate pharmacogenomic biomarkers and novel pathways associated with METRO-TOPO therapy that will serve as a foundation for further investigation and validation of METRO-TOPO as a novel treatment option for prostate cancers.

Pathogen-Induced Epigenetic Modifications in Cancers: Implications for Prevention, Detection and Treatment of Cancers in Africa

Cancer is a major public health burden worldwide. Tumor formation is caused by multiple intrinsic and extrinsic factors. Many reports have demonstrated a positive correlation between the burden of infectious pathogens and the occurrence of cancers. However, the mechanistic link between pathogens and cancer development remains largely unclear and is subject to active investigations. Apart from somatic mutations that have been widely linked with various cancers, an appreciable body of knowledge points to alterations of host epigenetic patterns as key triggers for cancer development. Several studies have associated various infectious pathogens with epigenetic modifications. It is therefore plausible to assume that pathogens induce carcinogenesis via alteration of normal host epigenetic patterns. Thus, Africa with its disproportionate burden of infectious pathogens is threatened by a dramatic increase in pathogen-mediated cancers. To curb the potential upsurge of such cancers, a better understanding of the role of tropical pathogens in cancer epigenetics could substantially provide resources to improve cancer management among Africans. Therefore, this review discusses cancer epigenetic studies in Africa and the link between tropical pathogens and cancer burden. In addition, we discuss the potential mechanisms by which pathogens induce cancers and the opportunities and challenges of tropical pathogen-induced epigenetic changes for cancer prevention, detection and management.

miR-148a, miR-152 and miR-200b promote prostate cancer metastasis by targeting DNMT1 and PTEN expression

MicroRNAs (miRs) modulate the expression of target genes in the signal pathway on transcriptome level. The present study investigated the ‘epigenetic-based miRNA (epi-miRNA)-mRNA’ regulatory network of miR-34b, miR-34c, miR-148a, miR-152, miR-200a and miR-200b epi-miRNAs and their target genes, DNA methyltransferase (DNMT1, 3a and 3b), phosphate and tensin homolog (PTEN) and NK3 Homeobox 1 (NKX3.1), in prostate cancer (PCa) using reverse transcription-quantitative PCR. The expression level of NKX3.1 were not significantly different between the PCa, Met-PCa and control groups. However, in the PCa and Met-PCa groups, the expression level of DNMT1 was upregulated, while DNMT3a, DNMT3b and PTEN were downregulated. Overexpression of DNMT1 (~5 and ~6-fold increase in the PCa and Met-PCa groups respectively) was accompanied by a decreased expression in PTEN, indicating a potential negative association. Both groups indicated that a high level of DNMT1 is associated with the aggressiveness of cancer, and there is a a directly proportional relationship between this gene and PSA, GS and TNM staging. A significant ~2 to ~5-fold decrease in the expression levels of DNMT3a and DNMT3b was found in both groups. In the PCa group, significant associations were identified between miR-34b and DNMT1/DNMT3b; between miR-34c/miR-148a and all target genes; between miR-152 and DNMT1/DNMT3b and PTEN; and between miR-200a/b and DNMT1. In the Met-PCa group, miR-148a, miR-152 and miR-200b exhibited a significant association with all target genes. A significant negative association was identified between PTEN and DNMT1 in the Met-PCa group. It was also revealed that that miR-148a, miR-152 and miR-200b increased the expression of DNMT1 and suppressed PTEN. Furthermore, the ‘epi-miRNA-mRNA’ bidirectional feedback loop was emphasised and the methylation pattern in PCa anti-cancer therapeutics was highlighted.

Racial disparity in prostate cancer in the African American population with actionable ideas and novel immunotherapies

BACKGROUND

African Americans (AAs) in the United States are known to have a higher incidence and mortality for Prostate Cancer (PCa). The drivers of this epidemiological disparity are multifactorial, including socioeconomic factors leading to lifestyle and dietary issues, healthcare access problems, and potentially tumor biology.

RECENT FINDINGS

Although recent evidence suggests once access is equal, AA men have equal outcomes to Caucasian American (CA) men, differences in PCa incidence remain, and there is much to do to reverse disparities in mortality across the USA. A deeper understanding of these issues, both at the clinical and molecular level, can facilitate improved outcomes in the AA population. This review first discusses PCa oncogenesis in the context of its diverse hallmarks before benchmarking key molecular and genomic differences for PCa in AA men that have emerged in the recent literature. Studies have emphasized the importance of tumor microenvironment that contributes to both the unequal cancer burden and differences in clinical outcome between the races. Management of comorbidities like obesity, hypertension, and diabetes will provide an essential means of reducing prostate cancer incidence in AA men. Although requiring further AA specific research, several new treatment strategies such as immune checkpoint inhibitors used in combination PARP inhibitors and other emerging vaccines, including Sipuleucel-T, have demonstrated some proven efficacy.

CONCLUSION

Genomic profiling to integrate clinical and genomic data for diagnosis, prognosis, and treatment will allow physicians to plan a "Precision Medicine" approach to AA men. There is a pressing need for further research for risk stratification, which may allow early identification of AA men with higher risk disease based on their unique clinical, genomic, and immunological profiles, which can then be mapped to appropriate clinical trials. Treatment options are outlined, with a concise description of recent work in AA specific populations, detailing several targeted therapies, including immunotherapy. Also, a summary of current clinical trials involving AA men is presented, and it is important that policies are adopted to ensure that AA men are actively recruited. Although it is encouraging that many of these explore the lifestyle and educational initiatives and therapeutic interventions, there is much still work to be done to reduce incidence and mortality in AA men and equalize current racial disparities.

The Pursuit of Health Equity and Equality in Urologic Oncology: Where We Have Been and Where We Are Going

CONTEXT

Advances in urologic oncology have improved early detection, treatment options, and health outcomes; however, racial/ethnic minorities continue to experience disparities in cancer incidence and survival. Research evaluating the optimal methods for closing these disparity gaps is under-reported.

OBJECTIVE

To highlight critical disparities in equity and equality in urologic oncology and identify ways in which health care professionals can reduce these disparities among disproportionately affected groups through a health equity-focused framework.

EVIDENCE ACQUISITION

A literature search was performed using EMBASE, MEDLINE, and PubMed. Articles were included if they were published in English from 1980 to 2021 and addressed barriers and health care disparities in urologic cancer care in racial/ethnic minorities. The same search was conducted to look at barriers and disparities according to gender and to lesbian, gay, bisexual, transgender, questioning, intersex, or asexual (LGBTQIA) identity, and among immigrant populations.

EVIDENCE SYNTHESIS

Racial/ethnic minorities in the USA are less likely to be screened for urologic cancers, are less likely to have an early diagnosis of cancer, and have a higher mortality rate than their white counterparts. In addition, major European and North American clinical trials lack proper representation of diverse populations, leading to a knowledge gap regarding effective methods for addressing cancer health disparities.

CONCLUSIONS

Continued medical advances have increased the efficacy of screening, diagnosis, and treatment of urologic cancers, but there remain significant well-documented disparities in the receipt of these advances among racial/ethnic minorities, women, LGBTQIA individuals, and immigrant populations. Multidisciplinary efforts are needed to address and ultimately eliminate these gaps.

PATIENT SUMMARY

We analyzed several studies to understand current disparities in cancer screening, diagnosis, and health outcomes across under-represented populations. We found that under-represented populations have worse outcomes than their white counterparts diagnosed with cancer. We conclude that the best way to address these disparities is through a multidisciplinary approach that involves engagement at the individual, community, research, and institutional levels to provide the best care possible to each individual patient.

Semen sampling as a simple, noninvasive surrogate for prostate health screening

The detection rates for prostate cancer (pCa) by invasive biopsy are high, fully justifying its use in confirmatory testing. False-positive results of prior, relatively insensitive screening tests, however, can lead to expensive and often unnecessary surgery. Several reports have suggested the potential use of the ejaculate to screen for prostate conditions. Hitherto, the potential impact of sterilization on the diagnostic potential of seminal plasma screening has not been examined. Herein, we report cellular and molecular comparisons of semen samples obtained from normal (N = 5), vasectomized (N = 5) and prostate pathology patients (N = 4; confirmed by a biopsy) that were centrifuged over 60% PureSperm cushions. Non-penetrating cells were washed prior to immunocytochemistry with prostatic epithelial cell markers including PSMA, NKX3.1 and CD24. KRT18 was used to highlight epithelial cells in these samples. RNA sequencing was then used to identify differentially expressed small RNAs associated with vasectomy and prostate pathology. Specific gene transcripts were confirmed by RT-qPCR. PMSA⁺/KRT18⁺, CD24⁺/KRT18⁺ and NKX3.1/⁺KRT18⁺ cells were observed, albeit infrequently in most processed semen samples by indirect immunocytochemistry. Targeted RT-qPCR supported their enrichment, along with their putative designation as prostatic luminal cells. Small RNAs in seminal plasma were highly heterogeneous, with tRNAs and miRNAs being the dominant forms. Hsa-miR-143 and hsa-miR-199 were among the most prominent of the differentially expressed miRNAs upregulated in samples with prostate pathology but not vasectomy. The targets of these small RNAs illustrate biological processes involved among others in transcription regulation and collagen metabolism. Our outcomes strongly support an appraisal of selected biologically meaningful small RNAs of ejaculate semen for prostate health screening. A long-term goal would be a simple, routine, noninvasive test for monitoring prostate health, potentially among younger men.

The role of HOTAIR/miR-152-3p/LIN28B in regulating the progression of endometrial squamous carcinoma

INTRODUCTION

There is growing evidence that long non-coding RNAs (lncRNAs) are correlated with malignancy in the modulation of tumor progression. This study aims to investigate the effect of homeobox protein (HOX) transcript antisense RNA (HOTAIR) on the migration and invasion of ESC.

MATERIAL AND METHODS

Starbase was used to identify miRNAs with complementary base pairing with HOTAIR. RNA pull-down and qRT-PCR were employed to investigate the effect of HOTAIR on miR-152-3p. In vitro cell migration and invasion assays were performed to assess the effects of HOTAIR and miR-152-3p on ESC. Computational software, TargetScan, was then used to identify the potential target of miR-152-3p, and their relationship was verified by immunoblotting analysis, qRT-PCR and luciferase reporter assay.

RESULTS

Starbase predicted a potential miR-152-3p binding site in HOTAIR, which was validated by RNA pull-down assay. HOTAIR was negatively correlated with miR-152-3p in ESC. Moreover, HOTAIR promoted migration and invasion of ESC. The oncogenic activity of HOTAIR was partly through its negative regulation of miR-152-3p. LIN28B was identified to be a direct target of miR-152-3p. A negative correlation between LIN28B and miR-152-3p was observed in ESC. In addition, overexpression of miR-152-3p suppressed the progression of ESC by directly targeting and regulating LIN28B.

CONCLUSIONS

Our results reveal that HOTAIR may be a driver of ESC through inhibiting miR-152-3p, a tumor suppressor, suggesting that miR-152-3p may be a potential target for advanced ESC therapeutic treatment.

Assessment of miR-98-5p, miR-152-3p, miR-326 and miR-4289 Expression as Biomarker for Prostate Cancer Diagnosis

Prostate cancer (PCa) is one of the most commonly diagnosed cancers worldwide, accounting for almost 1 in 5 new cancer diagnoses in the US alone. The current non-invasive biomarker prostate specific antigen (PSA) has lately been presented with many limitations, such as low specificity and often associated with over-diagnosis. The dysregulation of miRNAs in cancer has been widely reported and it has often been shown to be specific, sensitive and stable, suggesting miRNAs could be a potential specific biomarker for the disease. Previously, we identified four miRNAs that are significantly upregulated in plasma from PCa patients when compared to healthy controls: miR-98-5p, miR-152-3p, miR-326 and miR-4289. This panel showed high specificity and sensitivity in detecting PCa (area under the curve (AUC) = 0.88). To investigate the specificity of these miRNAs as biomarkers for PCa, we undertook an in depth analysis on these miRNAs in cancer from the existing literature and data. Additionally, we explored their prognostic value found in the literature when available. Most studies showed these miRNAs are downregulated in cancer and this is often associated with cancer progression and poorer overall survival rate. These results suggest our four miRNA signatures could potentially become a specific PCa diagnostic tool of which prognostic potential should also be explored.

Lung cancer health disparities

Compared with all other racial and ethnic groups in the United States, African Americans are disproportionally affected by lung cancer, both in terms of incidence and survival. It is likely that smoking, as the main etiological factor associated with lung cancer, contributes to these disparities, but the precise mechanism is still unclear. This paper seeks to explore the history of lung cancer disparities and review to the literature regarding the various factors that contribute to them.

Role of Alternative Splicing in Prostate Cancer Aggressiveness and Drug Resistance in African Americans

Alternative splicing, the process of removing introns and joining exons of pre-mRNA, is critical for growth, development, tissue homeostasis, and species diversity. Dysregulation of alternative splicing can initiate and drive disease. Aberrant alternative splicing has been shown to promote the "hallmarks of cancer" in both hematological and solid cancers. Of interest, recent work has focused on the role of alternative splicing in prostate cancer and prostate cancer health disparities. We will provide a review of prostate cancer health disparities involving the African American population, alternative RNA splicing, and alternative splicing in prostate cancer. Lastly, we will summarize our work on differential alternative splicing in prostate cancer disparities and its implications for disparate health outcomes and therapeutic targets.

Comparative Transcriptome Profiling Reveals Coding and Noncoding RNA Differences in NSCLC from African Americans and European Americans

Purpose: To determine whether racial differences in gene and miRNA expression translates to differences in lung tumor biology with clinical relevance in African Americans (AAs) and European Americans (EAs).Experimental Design: The NCI-Maryland Case Control Study includes seven Baltimore City hospitals and is overrepresented with AA patients (∼40%). Patients that underwent curative NSCLC surgery between 1998 and 2014 were enrolled. Comparative molecular profiling used mRNA (n = 22 AAs and 19 EAs) and miRNA (n = 42 AAs and 55 EAs) expression arrays to track differences in paired fresh frozen normal tissues and lung tumor specimens from AAs and EAs. Pathway enrichment, predicted drug response, tumor microenvironment infiltration, cancer immunotherapy antigen profiling, and miRNA target enrichment were assessed.Results: AA-enriched differential gene expression was characterized by stem cell and invasion pathways. Differential gene expression in lung tumors from EAs was primarily characterized by cell proliferation pathways. Population-specific gene expression was partly driven by population-specific miRNA expression profiles. Drug susceptibility predictions revealed a strong inverse correlation between AA resistance and EA sensitivity to the same panel of drugs. Statistically significant differences in M1 and M2 macrophage infiltration were observed in AAs (P < 0.05); however, PD-L1, PD-L2 expression was similar between both.Conclusions: Comparative transcriptomic profiling revealed clear differences in lung tumor biology between AAs and EAs. Increased participation by AAs in lung cancer clinical trials are needed to integrate, and leverage, transcriptomic differences with other clinical information to maximize therapeutic benefit in both AAs and EAs. Clin Cancer Res; 23(23); 7412-25. ©2017 AACR.

Biomarker microRNAs for prostate cancer metastasis: screened with a network vulnerability analysis model

Background

Prostate cancer (PCa) is a fatal malignant tumor among males in the world and the metastasis is a leading cause for PCa death. Biomarkers are therefore urgently needed to detect PCa metastatic signature at the early time. MicroRNAs are small non-coding RNAs with the potential to be biomarkers for disease prediction. In addition, computer-aided biomarker discovery is now becoming an attractive paradigm for precision diagnosis and prognosis of complex diseases.

Methods

In this study, we identified key microRNAs as biomarkers for predicting PCa metastasis based on network vulnerability analysis. We first extracted microRNAs and mRNAs that were differentially expressed between primary PCa and metastatic PCa (MPCa) samples. Then we constructed the MPCa-specific microRNA-mRNA network and screened microRNA biomarkers by a novel bioinformatics model. The model emphasized the characterization of systems stability changes and the network vulnerability with three measurements, i.e. the structurally single-line regulation, the functional importance of microRNA targets and the percentage of transcription factor genes in microRNA unique targets.

Results

With this model, we identified five microRNAs as putative biomarkers for PCa metastasis. Among them, miR-101-3p and miR-145-5p have been previously reported as biomarkers for PCa metastasis and the remaining three, i.e. miR-204-5p, miR-198 and miR-152, were screened as novel biomarkers for PCa metastasis. The results were further confirmed by the assessment of their predictive power and biological function analysis.

Conclusions

Five microRNAs were identified as candidate biomarkers for predicting PCa metastasis based on our network vulnerability analysis model. The prediction performance, literature exploration and functional enrichment analysis convinced our findings. This novel bioinformatics model could be applied to biomarker discovery for other complex diseases.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1506-7) contains supplementary material, which is available to authorized users.

A Plasma Biomarker Panel of Four MicroRNAs for the Diagnosis of Prostate Cancer

Prostate cancer is diagnosed in over 1 million men every year globally, yet current diagnostic modalities are inadequate for identification of significant cancer and more reliable early diagnostic biomarkers are necessary for improved clinical management of prostate cancer patients. MicroRNAs (miRNAs) modulate important cellular processes/pathways contributing to cancer and are stably present in body fluids. In this study we profiled 372 cancer-associated miRNAs in plasma collected before (~60% patients) and after/during commencement of treatment (~40% patients), from age-matched prostate cancer patients and healthy controls, and observed elevated levels of 4 miRNAs - miR-4289, miR-326, miR-152-3p and miR-98-5p, which were validated in an independent cohort. The miRNA panel was able to differentiate between prostate cancer patients and controls (AUC = 0.88). Analysis of published miRNA transcriptomic data from clinical samples demonstrated low expression of miR-152-3p in tumour compared to adjacent non-malignant tissues. Overexpression of miR-152-3p increased proliferation and migration of prostate cancer cells, suggesting a role for this miRNA in prostate cancer pathogenesis, a concept that was supported by pathway analysis of predicted miR-152-3p target genes. In summary, a four miRNA panel, including miR-152-3p which likely targets genes with key roles in prostate cancer pathogenesis, has the potential to improve early prostate cancer diagnosis.

A multiplatform approach identifies miR-152-3p as a common epigenetically regulated onco-suppressor in prostate cancer targeting TMEM97

Background

Prostate cancer (PCa) is a major cause of morbidity and mortality in men worldwide. MicroRNAs are globally downregulated in PCa, especially in poorly differentiated tumors. Nonetheless, the underlying mechanisms are still elusive. Herein, using combined analysis of microRNAs expression and genomewide DNA methylation, we aimed to identify epigenetically downregulated microRNAs in PCa.

Results

We found that miR-152-3p was underexpressed in PCa and that lower expression levels were associated with promoter hypermethylation in accordance with TCGA dataset analysis. Functional in vitro assays suggest that miR-152-3p suppresses cell viability and invasion potential, whereas it promotes cell cycle arrest at S and G2/M phases. Additionally, miR-152-3p expression was associated with longer disease-free survival in PCa patients from TCGA. Finally, TMEM97, which is overexpressed in PCa, was identified as a novel miR-152-3p target gene.

Conclusions

Our findings demonstrate the advantages of using a combinatory approach to identify microRNAs downregulated due to aberrant promoter methylation. MiR-152-3p downregulation and promoter methylation was found to be prevalent in primary PCa, which impairs its role in control of cell viability, cell cycle regulation and invasion.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0475-2) contains supplementary material, which is available to authorized users.

MiR-152 functioning as a tumor suppressor that interacts with DNMT1 in nasopharyngeal carcinoma

Background

In recent years, miR-152 has been dysregulated in a variety of tumors and used as a tumor suppressor. Nevertheless, its role in nasopharyngeal carcinoma (NPC) remains unidentified.

Materials and methods

Real-time quantitative PCR (polymerase chain reaction) was performed to analyze the expression of miR-152 in NPC cell lines. MiR-152 expression profiles in NPC tissues were obtained from Gene Expression Omnibus (GEO GSE36682). The effect of miR-152 on the invasion and proliferation of NPC cells was determined through cell invasion, wound healing, and cell viability assays. Apoptosis was examined by flow cytometry, and Western blot was performed to measure expression of the target gene. Pyrosequencing was used to detect the methylation level of NPC cells.

Results

In this study, miR-152 was downregulated in the NPC tissues and cell lines. When miR-152 was enhanced, the invasion and migration of NPC cells were inhibited. However, miR-152 had no effect on the proliferation of NPC cells. Luciferase reporter gene analysis was performed, and the results showed that DNMT1 (DNA (cytosine-5)-methyltransferase 1) is a direct target of miR-152 in NPC cells. DNMT1 downregulation and miR-152 overexpression both reversed the effects of miR-152 inhibition on the NPC cells. In addition, miR-152 expression increased as a result of the inhibition of the methylation level of miR-152 when DNMT1 expression was downregulated.

Conclusion

The overexpression of miR-152 inhibited the migration and invasion of NPC cells by targeting DNMT1. Furthermore, DNMT1 regulated miR-152 expression through DNA methylation. Overall, the novel miR-152-DNMT1 regulatory circuit may provide better understanding of the pathogenesis of NPC and new epigenetic therapeutic target in NPC.

Identification of tumor suppressive role of microRNA-132 and its target gene in tumorigenesis of prostate cancer

Previous literature exists on the role of microRNA (miR)-132 in initiation and progression of various malignancies. In this study, we aimed at understanding the relationship of miR-132 of prostate tumorigenesis. We collected 32 prostate cancer tissues and adjacent non-cancerous controls, and detected the expression level of miR-132. Then the miRNA database was searched online and luciferase assay perform to understand the regulatory relationship between miR-132 and E2F5. Moreover, we also conducted real-time PCR and western blot analysis to study the mRNA and protein expression level of E2F5 among different groups (cancerous tissue, n=32; non-cancerous tissue, n=32) or cells treated with scramble control, miR-132 mimics, E2F5 siRNA and miR-132 inhibitors. miR-132 was upregulated in cancerous tissues of prostate cancer patients. E2F5 was the target of miR-132, and negative regulatory relationship between miR-132 and E2F5 was also confirmed by luciferase assay. The mRNA and protein expression level of E2F5 increased in cancerous tissue group. miR-132 decreased the expression of E2F5 in prostate cancer cells, and introduction of miR-132 reduced the viability and E2F5 and promoted the viability of prostate cancer cells. miR-132 inhibited apoptosis and E2F5 accelerated apoptosis. In conclusion, miR-132 was upregulated in cancerous tissue of prostate cancer. E2F5 was a direct target of miR-132, and downregulation of E2F5 caused by upregulation of miR-132 may contribute to the tumorigenesis of prostate cancer.

The potential of microRNAs as human prostate cancer biomarkers: A meta-analysis of related studies

Prostate cancer (PC) is a very important kind of male malignancies. When PC evolves into a stage of hormone resistance or metastasis, the fatality rate is very high. Currently, discoveries and advances in miRNAs as biomarkers have opened the potential for the diagnosis of PC, especially early diagnosis. miRNAs not only can noninvasively or minimally invasively identify PC, but also can provide the data for optimization and personalization of therapy. Moreover, miRNAs have been shown to play an important role to predict prognosis of PC. The purpose of this meta‐analysis is to integrate the currently published expression profile data of miRNAs in PC, and evaluate the value of miRNAs as biomarkers for PC. All of relevant records were selected via electronic databases: Pubmed, Embase, Cochrane, and CNKI based on the assessment of title, abstract, and full text. we extracted mean ± SD or fold change of miRNAs expression levels in PC versus BPH or normal controls. Pooled hazard ratios (HRs) with 95% confidence intervals (CI) for overall survival (OS) and recurrence‐free survival (RFS), were also calculated to detect the relationship between high miRNAs expression and PC prognosis. Selected 104 articles were published in 2007‐2017. According to the inclusion criteria, 104 records were included for this meta‐analysis. The pooled or stratified analyze showed 10 up‐regulated miRNAs (miR‐18a, miR‐34a, miR‐106b, miR‐141, miR‐182, miR‐183, miR‐200a/b, miR‐301a, and miR‐375) and 14 down‐regulated miRNAs (miR‐1, miR‐23b/27b, miR‐30c, miR‐99b, miR‐139‐5p, miR‐152, miR‐187, miR‐204, miR‐205, miR‐224, miR‐452, miR‐505, and let‐7c) had relatively good diagnostic and predictive potential to discriminate PC from BPH/normal controls. Furthermore, high expression of miR‐32 and low expression of let‐7c could be used to differentiate metastatic PC from local/primary PC. Additional interesting findings were that the expression profiles of five miRNAs (miR‐21, miR‐30c, miR‐129, miR‐145, and let‐7c) could predict poor RFS of PC, while the evaluation of miR‐375 was associated with worse OS. miRNAs are important regulators in PC progression. Our results indicate that miRNAs are suitable for predicting the different stages of PC. The detection of miRNAs is an effective way to control patient's prognosis and evaluate therapeutic efficacy. However, large‐scale detections based on common clinical guidelines are still necessary to further validate our conclusions, due to the bias induced by molecular heterogeneity and differences in study design and detection methods.

Molecular mechanisms involving prostate cancer racial disparity

Prostate cancer (PCa) is the second leading cause of cancer-related deaths in the United States. The African (AA) descent has greater incidence and mortality rates of PCa as compared to Caucasian (CA) men. While socioeconomic differences across racial groups contribute to disparity in PCa, increasing evidence points that genetic and molecular alterations play important roles in racial disparities associated with PCa. In this review, we focus on genetic and molecular influences that contribute to racial disparity between AA and CA men including: androgen and estrogen receptor signaling pathways, growth factors, apoptotic proteins, genetic, genomic and epigenetic alterations. Future translational studies will identify prognostic and predictive biomarkers for AA PCa and assist in the development of new targeted-therapies specifically for AA men with PCa.

Clinical significance of miRNA host gene promoter methylation in prostate cancer

Only a part of prostate cancer (PCa) patients has aggressive malignancy requiring adjuvant treatment after radical prostatectomy (RP). Biomarkers capable to predict biochemical PCa recurrence (BCR) after RP would significantly improve preoperative risk stratification and treatment decisions. MicroRNA (miRNA) deregulation has recently emerged as an important phenomenon in tumor development and progression, however, the mechanisms remain largely unstudied. In the present study, based on microarray profiling of DNA methylation in 9 pairs of PCa and noncancerous prostate tissues (NPT), host genes of miR-155-5p, miR-152-3p, miR-137, miR-31-5p, and miR-642a, -b were analyzed for promoter methylation in 129 PCa, 35 NPT, and 17 benign prostatic hyperplasia samples (BPH) and compared to the expression of mature miRNAs and their selected targets (DNMT1, KDM1A, and KDM5B). The Cancer Genome Atlas dataset was utilized for validation. Methylation of mir-155, mir-152, and mir-137 host genes was PCa-specific, and downregulation of miR-155-5p significantly correlated with promoter methylation. Higher KDM5B expression was observed in samples with methylated mir-155 or mir-137 promoters, whereas upregulation of KDM1A and DNMT1 was associated with mir-155 and mir-152 methylation status, respectively. Promoter methylation of mir-155, mir-152, and mir-31 was predictive of BCR-free survival in various Cox models and increased the prognostic value of clinicopathologic factors. In conclusion, methylated mir-155, mir-152, mir-137, and mir-31 host genes are promising diagnostic and/or prognostic biomarkers of PCa. Methylation status of particular miRNA host genes as independent variables or in combinations might assist physicians in identifying poor prognosis PCa patients preoperatively.

Racial health disparities in ovarian cancer: not just black and white

Ovarian cancer (OC) is the most lethal gynecological malignancy, which disproportionately affects African American (AA) women. Lack of awareness and socioeconomic factors are considered important players in OC racial health disparity, while at the same time, some recent studies have brought focus on the genetic basis of disparity as well. Differential polymorphisms, mutations and expressions of genes have been reported in OC patients of diverse racial and ethnic backgrounds. Combined, it appears that neither genetic nor the socioeconomic factors alone might explain the observed racially disparate health outcomes among OC patients. Rather, a more logical explanation would be the one that takes into consideration the combination and/or the interplay of these factors, perhaps even including some environmental ones. Hence, in this article, we attempt to review the available information on OC racial health disparity, and provide an overview of socioeconomic, environmental and genetic factors, as well as the epigenetic changes that can act as a liaison between the three. A better understanding of these underlying causes will help further research on effective cancer management among diverse patient population and ultimately narrow health disparity gaps.

Proteomic characterization of paired non-malignant and malignant African-American prostate epithelial cell lines distinguishes them by structural proteins

Background

While many factors may contribute to the higher prostate cancer incidence and mortality experienced by African-American men compared to their counterparts, the contribution of tumor biology is underexplored due to inadequate availability of African-American patient-derived cell lines and specimens. Here, we characterize the proteomes of non-malignant RC-77 N/E and malignant RC-77 T/E prostate epithelial cell lines previously established from prostate specimens from the same African-American patient with early stage primary prostate cancer.

Methods

In this comparative proteomic analysis of RC-77 N/E and RC-77 T/E cells, differentially expressed proteins were identified and analyzed for overrepresentation of PANTHER protein classes, Gene Ontology annotations, and pathways. The enrichment of gene sets and pathway significance were assessed using Gene Set Enrichment Analysis and Signaling Pathway Impact Analysis, respectively. The gene and protein expression data of age- and stage-matched prostate cancer specimens from The Cancer Genome Atlas were analyzed.

Results

Structural and cytoskeletal proteins were differentially expressed and statistically overrepresented between RC-77 N/E and RC-77 T/E cells. Beta-catenin, alpha-actinin-1, and filamin-A were upregulated in the tumorigenic RC-77 T/E cells, while integrin beta-1, integrin alpha-6, caveolin-1, laminin subunit gamma-2, and CD44 antigen were downregulated. The increased protein level of beta-catenin and the reduction of caveolin-1 protein level in the tumorigenic RC-77 T/E cells mirrored the upregulation of beta-catenin mRNA and downregulation of caveolin-1 mRNA in African-American prostate cancer specimens compared to non-malignant controls. After subtracting race-specific non-malignant RNA expression, beta-catenin and caveolin-1 mRNA expression levels were higher in African-American prostate cancer specimens than in Caucasian-American specimens. The “ECM-Receptor Interaction” and “Cell Adhesion Molecules”, and the “Tight Junction” and “Adherens Junction” pathways contained proteins are associated with RC-77 N/E and RC-77 T/E cells, respectively.

Conclusions

Our results suggest RC-77 T/E and RC-77 N/E cell lines can be distinguished by differentially expressed structural and cytoskeletal proteins, which appeared in several pathways across multiple analyses. Our results indicate that the expression of beta-catenin and caveolin-1 may be prostate cancer- and race-specific. Although the RC-77 cell model may not be representative of all African-American prostate cancer due to tumor heterogeneity, it is a unique resource for studying prostate cancer initiation and progression.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3462-7) contains supplementary material, which is available to authorized users.

Resveratrol and pterostilbene as a microRNA-mediated chemopreventive and therapeutic strategy in prostate cancer

Growing evidence indicates that deregulation of the epigenetic machinery comprising the microRNA (miRNA) network is a critical factor in the progression of various diseases, including cancer. Concurrently, dietary phytochemicals are being intensively studied for their miRNA-mediated health-beneficial properties, such as anti-inflammatory, cardioprotective, antioxidative, and anticancer properties. Available experimental data have suggested that dietary polyphenols may be effective miRNA-modulating chemopreventive and therapeutic agents. Moreover, noninvasive detection of changes in miRNA expression in liquid biopsies opens enormous possibilities for their clinical utilization as novel prognostic and predictive biomarkers. In our published studies, we identified resveratrol-regulated miRNA profiles in prostate cancer. Resveratrol downregulated the phosphatase and tensin homolog (PTEN)-targeting members of the oncogenic miR-17 family of miRNAs, which are overexpressed in prostate cancer. We have functionally validated the miRNA-mediated ability of resveratrol and its potent analog pterostilbene to rescue the tumor suppressor activity of PTEN in vitro and in vivo. Taken together, our findings implicate the use of resveratrol and its analogs as an attractive miRNA-mediated chemopreventive and therapeutic strategy in prostate cancer and the use of circulating miRNAs as potential predictive biomarkers for clinical development.

Epigenetic basis of cancer health disparities: Looking beyond genetic differences

Despite efforts at various levels, racial health disparities still exist in cancer patients. These inequalities in incidence and/or clinical outcome can only be explained by a multitude of factors, with genetic basis being one of them. Several investigations have provided convincing evidence to support epigenetic regulation of cancer-associated genes, which results in the differential transcriptome and proteome, and may be linked to a pre-disposition of individuals of certain race/ethnicity to early or more aggressive cancers. Recent technological advancements and the ability to quickly analyze whole genome have aided in these efforts, and owing to their relatively easy detection, methylation events are much well-characterized, than the acetylation events, across human populations. The early trend of investigating a pre-determined set of genes for differential epigenetic regulation is paving way for more unbiased screening. This review summarizes our current understanding of the epigenetic events that have been tied to the racial differences in cancer incidence and mortality. A better understanding of the epigenetics of racial diversity holds promise for the design and execution of novel strategies targeting the human epigenome for reducing the disparity gaps.

miRNAs as drivers of TMPRSS2-ERG negative prostate tumors in African American men

African Americans (AAs) who have PCa typically have more aggressive disease and make up a disproportionate number of the disease deaths, relative to European Americans (EAs). TMPRSS2 translocations, a common event in EA patients, are exploited in diagnostic and prognostic settings, whereas they are diminished in frequency in AA men. Thus, these patients with TMPRSS2 fusion-negative disease represent an under-investigated patient group. We propose that epigenetic events are a significant and alternative driver of aggressive disease in fusion-negative PCa. To reveal epigenetically governed microRNAs (miRNAs) that are enriched in fusion-negative disease and associated with aggressive in AA PCa, we leveraged both our experimental evidence and publically available data. These analyses identified 18 miRNAs that are differentially altered in fusion-negative disease, associated with DNA CpG methylation, and implicated in aggressive and AA PCas. Understanding the relationships between miRNA expression, upstream epigenetic regulation by DNA methylation, and downstream regulation of mRNA targets in fusion negative disease is imperative to understanding the biological basis of the racial health disparity in PCa.

Racial disparities in prostate cancer: a molecular perspective

Prostate cancer incidence and mortality rates are remarkably higher in African-American men as compared to their European-Americans counterparts. Despite these recognitions, precise causes underlying such prevalent racial disparities remain poorly understood. Although socioeconomic factors could account for such differences up to a certain extent, it is now being increasingly realized that such disparity has a molecular basis. Indeed, several differences, including genetic polymorphism, gene mutations, epigenetic modifications, miRNAs alterations, etc., have been reported in malignant prostate tissues from patients of diverse racial backgrounds. Here, we attempt to provide a molecular perspective on prostate cancer racial disparities by gathering available information on these associated factors and discussing their potential significance in disproportionate incidence and clinical outcomes.

Kaiso, a transcriptional repressor, promotes cell migration and invasion of prostate cancer cells through regulation of miR-31 expression

Kaiso, a member of the BTB/POZ zinc finger protein family, functions as a transcriptional repressor by binding to sequence-specific Kaiso binding sites or to methyl-CpG dinucleotides. Previously, we demonstrated that Kaiso overexpression and nuclear localization correlated with the progression of prostate cancer (PCa). Therefore, our objective was to explore the molecular mechanisms underlying Kaiso-mediated PCa progression. Comparative analysis of miRNA arrays revealed that 13 miRNAs were significantly altered (> 1.5 fold, p < 0.05) in sh-Kaiso PC-3 compared to sh-Scr control cells. Real-time PCR validated that three miRNAs (9, 31, 636) were increased in sh-Kaiso cells similar to cells treated with 5-aza-2′-deoxycytidine. miR-31 expression negatively correlated with Kaiso expression and with methylation of the miR-31 promoter in a panel of PCa cell lines. ChIP assays revealed that Kaiso binds directly to the miR-31 promoter in a methylation-dependent manner. Over-expression of miR-31 decreased cell proliferation, migration and invasiveness of PC-3 cells, whereas cells transfected with anti-miR-31 restored proliferation, migration and invasiveness of sh-Kaiso PC-3 cells. In PCa patients, Kaiso high/miR-31 low expression correlated with worse overall survival relative to each marker individually. In conclusion, these results demonstrate that Kaiso promotes cell migration and invasiveness through regulation of miR-31 expression.

Recent scenario of microRNA as diagnostic and prognostic biomarkers of prostate cancer

Prostate cancer (CaP) is a leading cause of cancer death and displays a broad range of clinical behavior from relatively indolent to aggressive metastatic disease. Due to the alteration and incomplete characterization of the CaP genomic markers, the quest for novel cellular metabolic regulatory molecules like micro RNA (miRNA) as a biomarker could be considered for the prognosis and treatment of CaP in future. In this article, we review the existing literature pertaining to CaP. Study provides a comprehensive miRNA profile expressed in CaP. Beside the miRNA expressed in the tumor tissue, circulating miRNAs have been found highly stable and are both detectable and quantifiable in a range of accessible bio fluids; therefore, miRNA has the potential to be useful diagnostic, prognostic and predictive biomarker. Along with being an important molecule in modulation of CaP progression, the miRNA have certain limitations such as lack of stable expression of multiple target genes and often disrupt entire signaling networks of cellular metabolic pathways. We conclude that: The alteration of miRNA and their role played in cellular regulatory networks would be the next target of basic research in CaP. The miRNAs identified may be validated and modeled to understand their role in CaP, using bioinformatics. There is an immediate unmet need in the translational approach of identified miRNAs. The characterization of miRNAs involved in CaP is still incomplete: adequate validation studies are required to corroborate current results.

A functional microRNA library screen reveals miR-410 as a novel anti-apoptotic regulator of cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma is characterized by late diagnosis and a poor survival rate. MicroRNAs have been involved in the pathogenesis of different cancer types, including cholangiocarcinoma. Our aim was to identify novel microRNAs regulating cholangiocarcinoma cell growth in vitro and in vivo.

METHODS

A functional microRNA library screen was performed in human cholangiocarcinoma cells to identify microRNAs that regulate cholangiocarcinoma cell growth. Real-time PCR analysis evaluated miR-9 and XIAP mRNA levels in cholangiocarcinoma cells and tumors.

RESULTS

The screen identified 21 microRNAs that regulated >50 % cholangiocarcinoma cell growth. MiR-410 was identified as the top suppressor of growth, while its overexpression significantly inhibited the invasion and colony formation ability of cholangiocarcinoma cells. Bioinformatics analysis revealed that microRNA-410 exerts its effects through the direct regulation of the X-linked inhibitor of apoptosis protein (XIAP). Furthermore, overexpression of miR-410 significantly reduced cholangiocarcinoma tumor growth in a xenograft mouse model through induction of apoptosis. In addition, we identified an inverse relationship between miR-410 and XIAP mRNA levels in human cholangiocarcinomas.

CONCLUSIONS

Taken together, our study revealed a novel microRNA signaling pathway involved in cholangiocarcinoma and suggests that manipulation of the miR-410/XIAP pathway could have a therapeutic potential for cholangiocarcinoma.

miR-152 as a tumor suppressor microRNA: Target recognition and regulation in cancer

MicroRNAs (miRNAs or miRs) are endogenous translation repressors of protein-coding genes that act by binding to the 3'-untranslated region of their target genes, and may contribute to tumorigenesis by functioning as oncogenes or tumor suppressor genes. miR-152, a member of the miR-148/152 family, is aberrantly expressed in various diseases, including various types of cancer. A growing body of evidence has demonstrated that miR-152 may act as a tumor suppressor gene by regulating its target genes, which are associated with cell proliferation, migration and invasion in human cancer. In the present review, the gene structure and functions of miR-152 are discussed, and in particular, its regulatory mechanism, experimentally validated targets and tumor suppressor role in cancer, are highlighted.

Evaluation of Plasma miR-21 and miR-152 as Diagnostic Biomarkers for Common Types of Human Cancers

Stable blood based miRNA species have allowed for the differentiation of patients with various types of cancer. Therefore, specific blood-based miRNA might be considered as a methodology which could be informative of the presence of cancer potentially from multiple distinct organ sites. Recently, miR-21 has been identified as an “oncomir” in various tumors while miR-152 as a tumor suppressor. In this study, we investigated whether circulating miR-21 and miR-152 can be used for early detection of lung cancer (LuCa), colorectal carcinoma (CRC), breast cancer (BrCa) and prostate cancer (PCa), with distinguishing cancer from various benign lesions on these organ sites. We measured the two miRNA levels by using real-time RT-PCR in plasma samples from a total of 204 cancer patients, 159 various benign lesions, and 228 normal subjects. We observed significantly elevated expression of miR-21 and miR-152 in LuCa, CRC, and BrCa when compared with normal controls. We also found upregulation of plasma miR-21 and miR-152 levels in patients with benign lesions of lung and breast, as compared to normal controls, respectively. No significant expression variation of the two miRNAs was observed in PCa or prostatic benign lesions as compared to healthy controls. Receiver operating characteristic (ROC) analyses revealed that miR-21 and/or miR-152 can discriminate LuCa, CRC and BrCa from normal controls. Our results suggest that plasma miR-21 and miR-152 may serve as non-specific noninvasive biomarkers for early screening of LuCa, CRC, and BrCa, but not PCa.

Epigenetic and miRNAs Dysregulation in Prostate Cancer: The role of Nutraceuticals

The control of cancer onset and progression is recognized to benefit from specific molecular targeting. MiRNAs are increasingly being implicated in prostate cancer, and the evidence suggests they are possible targets for molecular therapy and diagnosis. In cancer cells, growing attention has been dedicated to novel molecular mechanisms linking the epigenetic scenario to miRNA dysregulation. Currently, the rising evidence shows that nutritional and natural agents, the so-called nutraceuticals, could modulate miRNAs expression, and, as a consequence, might influence cellular responses in health or diseases conditions, including cancer. Among dietary components, plant-derived polyphenols are receiving wide interest, either for their anti-aging and anti-oxidant properties, or for their more general "cell-protective" effects. Above all, their role in preventing the occurrence/recurrence of cancer and, in particular, their potentiality in nutritional intervention for modulating the functions of miRNAs and the epigenetic mechanisms, is still under active debate. This review is focused on the more recent highlights of the impact of miRNAs dysregulation on the onset and progression of prostate cancer, their interplay with epigenetic control and their modulation by natural agents.

An integrated genome-wide approach to discover deregulated microRNAs in non-small cell lung cancer: Clinical significance of miR-23b-3p deregulation

In spite of significant technical advances, genesis and progression of non-small cell lung cancer (NSCLC) remain poorly understood. We undertook an integrated genetic approach to discover novel microRNAs that were deregulated in NSCLCs. A total 119 primary NSCLCs with matched normal were analyzed for genome-wide copy number changes. We also tested a subset of matched samples by microRNA expression array, and integrated them to identify microRNAs positioned in allelic imbalance area. Our findings support that most of the identified deregulated microRNAs (miR-21, miR-23b, miR-31, miR-126, miR-150, and miR-205) were positioned in allelic imbalance areas. Among microRNAs tested in independent 114 NSCLCs, overexpression of miR-23b was revealed to be a significantly poor prognostic factor of recurrence free survival (HR = 2.40, P = 0.005, 95%CI: 1.32–4.29) and overall survival (HR = 2.35, P = 0.005, 95%CI: 1.30–4.19) in multivariable analysis. In addition, overexpression of miR-23b in H1838 cell line significantly increased cell proliferation, while inhibition of miR-23b in H1437 and H1944 cell lines significantly decreased cell doubling time. In summary, integration of genomic analysis and microRNA expression profiling could identify novel cancer-related microRNAs, and miR-23b could be a potential prognostic marker for early stage NSCLCs. Further biological studies of miR-23b are warranted for the potential development of targeted therapy.

MicroRNA-410 functions as a tumor suppressor by targeting angiotensin II type 1 receptor in pancreatic cancer

MicroRNAs (miRNAs) act as key regulators of gene expression in diverse biological processes and are intimately involved in tumorigenesis. However, the underlying molecular mechanisms of miR-410 in pancreatic cancer remain poorly understood. In this study, we found that miR-410 overexpression suppressed pancreatic cancer cell growth in vitro and in vivo as well as cell invasion and migration. miR-410 also resulted in G1/S cell-cycle arrest. We then showed that angiotensin II type 1 receptor (AGTR1) was a direct target of miR-410, with miR-410 suppressing AGTR1 expression levels. In contrast, inhibition of miR-410 increased the expression of AGTR1. Silencing of AGTR1 inhibited cell growth and invasion, similar to miR-410 overexpression. In addition, we found that the induction of vascular endothelial growth factor and the activation of the ERK signaling pathway by angiotensin II were blocked by miR-410, similar to the angiotensin II inhibitor losartan. miR-410 overexpression inhibited angiogenesis in mice through the repression of CD31 expression. ERK pathway knockdown suppressed pancreatic cancer cell proliferation, invasion, and angiogenesis. Finally, we found that miR-410 was downregulated in pancreatic cancer tissues compared to adjacent nontumor tissues, whereas AGTR1 was upregulated in pancreatic cancer tissues. Pearson correlation analysis showed that miR-410 and AGTR1 were inversely expressed. In conclusion, our data indicate that miR-410 suppresses pancreatic cancer growth, cell invasion, migration, and angiogenesis via the downregulation of AGTR1, acting as a tumor-suppressive miRNA. In addition, our results suggest that miR-410 is a potential diagnostic biomarker and therapeutic target for patients with pancreatic cancer.

Role of MicroRNAs in Prostate Cancer Pathogenesis

Prostate cancer (PCa) remains the most commonly diagnosed malignant tumor in men, and is the second highest cause of cancer mortality after lung tumors in the United States. Accumulating research indicates that microRNAs (miRNAs) are increasingly being implicated in PCa. miRNAs are conserved small noncoding RNAs that control gene expression posttranscriptionally. Recent profiling research suggests that miRNAs are aberrantly expressed in PCa, and these have been implicated in the regulation of apoptosis, cell cycle, epithelial to mesenchymal transition, PCa stem cells, and androgen receptor pathway. All of these might provide the basis for new approaches for PCa. Here, we review current findings regarding miRNA research in PCa to provide a strong basis for future study aimed at promising contributions of miRNA in PCa.

Novel RNA markers in prostate cancer: functional considerations and clinical translation

The availability of ultra-high throughput DNA and RNA sequencing technologies in recent years has led to the identification of numerous novel transcripts, whose functions are unknown as yet. Evidence is accumulating that many of these molecules are deregulated in diseases, including prostate cancer, and potentially represent novel targets for diagnosis and therapy. In particular, functional genomic analysis of microRNA (miRNA) and long noncoding RNA (lncRNA) in cancer is likely to contribute insights into tumor development. Here, we compile recent efforts to catalog differential expression of miRNA and lncRNA in prostate cancer and to understand RNA function in tumor progression. We further highlight technologies for molecular characterization of noncoding RNAs and provide an overview of current activities to exploit them for the diagnosis and therapy of this complex tumor.