Association study of miR-100, miR-124-1, miR-218-2, miR-301b, miR-605, and miR-4293 polymorphisms and the risk of breast cancer in a sample of Iranian population

miRNA genetic variations associated with the predisposition of oral squamous cell carcinoma in central Indian population

The disease burden of Oral Squamous Cell Carcinoma (OSCC) is rising day-by-day and is expected to rise 62 % through 2035. The chewing of tobacco, areca nut, and betel leaf, poor oral hygiene, and chronic infection are common risk factors of OSCC, but genetic and epigenetic factors also contribute equally. MicroRNAs (miRNAs) are comprised of small, non-coding endogenous RNA that regulate a plethora of biological activities by targeting messenger RNA through degradation or inhibition. Single Nucleotide Polymorphisms (SNPs) in miRNA genes can regulate the development and progression of OSCC. The present study aimed to determine the association between SNPs in miRNA genes (miRSNPs) with the risk of OSCC. A case-control study involving 225 histo-pathologically confirmed OSCC cases and 225 healthy controls was conducted, where 25 miRSNPs were analyzed by iPLEX MassArray analysis. A SNP rs12220909 in MIR4293 showed a highly protective effect (CC vs GG, OR = 0.0431, 95%CI = 0.005-0.323, p = 3e-6). Whereas three SNPs, namely, rs4705342 in MIR143 (CC vs TT, OR = 2.25, 95%CI = 2.00-2.53, p = 0.0008), rs531564 in MIR124 (CC vs GG, OR = 24.18, 95%CI = 3.22-181.37, p = 3e-6), and rs3746444 in MIR499 (AA vs GG, OR = 2.01, 95%CI = 1.32-3.05, p = 0.001) were significantly associated with a higher risk of OSCC. Additionally, NanoString-based nCounter miRNA expression profiling revealed that miR-499a (Log2FC = -1.07), and miR-143 (Log2FC = -1.56) were aberrantly expressed in OSCC tissue. Taken together, the above miSNPs may contribute to the high incidence of OSCC in central India. However, further studies with large cohorts and ethnic stratification are required to validate our findings.

MicroRNA Variants miR-27a rs895819 and miR-423 rs6505162, but not miR-124-1 rs531564, are Linked to Endometriosis and its Severity

Background: While different studies have investigated the association of SNPs with female reproductive disorders, a limited number of studies have investigated the effect of microRNAs variants in endometriosis. In this study, we evaluated the prevalence and the association of three different miRNAs variants including, miR-27a rs895819, miR-124-1 rs531564, and miR-423 rs6505162 with endometriosis to help further elucidate the importance of these variants in female reproductive disorders.

Methods: A total number of 440 women (220 cases and 220 controls) were included. DNA was extracted and genotyping of the SNPs was carried out by PCR.

Results: The results showed that rs895819 and rs6505162 had a significant association with endometriosis under the dominant, recessive, co-dominant, and allelic model, but rs531564 was not linked to endometriosis. Our results also imply a protective effect on endometriosis severity for AG genotype and G allele in rs895819 (p < 0.001), and also for AA and AC genotypes in rs6505162 with severity in endometriosis (p < 0.001). Moreover, Hardy–Weinberg equilibrium, haplotype frequency, and linkage disequilibrium between SNPs were performed.

Conclusion: miR-27a rs895819 and miR-423 rs6505162, but not miR-124-1 rs531564, are linked to endometriosis.

Association between single-nucleotide polymorphisms in miRNA and breast cancer risk: an updated review

Breast cancer (BC), a heterogeneous, aggressive illness with high mortality, is essentially a genomic disease. While the high-penetrance genes BRCA1 and BRCA2 play important roles in tumorigenesis, moderate- and low-penetrance genes are also involved. Single-nucleotide polymorphisms (SNPs) in microRNA (miRNA) genes have recently been identified as BC risk factors. miRNA genes are currently classified as low-penetrance. SNPs are the most common variations in the human genome. While the role of miRNA SNPs in BC susceptibility has been studied extensively, results have been inconsistent. This review analyzes the results of association studies between miRNA SNPs and BC risk from countries around the world. We conclude that: (a) By continent, the largest proportion of studies to date were conducted in Asia (65.0 %) and the smallest proportion in Africa (1.8 %); (b) Association studies have been completed for 67 different SNPs; (c) 146a, 196a2, 499, 27a, and 423 are the most-studied miRNAs; (d) The SNPs rs2910164 (miRNA-146a), rs11614913 (miRNA-196a2), rs3746444 (miRNA-499) and rs6505162 (miRNA-423) were the most widely associated with increased BC risk; (e) The majority of studies had small samples, which may affect the precision and power of the results; and (f) The effect of an SNP on BC risk depends on the ethnicity of the population. This review also discusses potential explanations for controversial findings.

miR-4293 upregulates lncRNA WFDC21P by suppressing mRNA-decapping enzyme 2 to promote lung carcinoma proliferation

Non-coding RNAs (ncRNAs) involve in diverse biological processes by post-transcriptional regulation of gene expression. Emerging evidence shows that miRNA-4293 plays a significant role in the development of non-small cell lung cancer. However, the oncogenic functions of miR-4293 have not been studied. Our results demonstrated that miR-4293 expression is markedly enhanced in lung carcinoma tissue and cells. Moreover, miR-4293 promotes tumor cell proliferation and metastasis but suppresses apoptosis. Mechanistic investigations identified mRNA-decapping enzyme 2 (DCP2) as a target of miR-4293 and its expression is suppressed by miR-4293. DCP2 can directly or indirectly bind to WFDC21P and downregulates its expression. Consequently, miR-4293 can further promote WFDC21P expression by regulating DCP2. With a positive correlation to miR-4293 expression, WFDC21P also plays an oncogenic role in lung carcinoma. Furthermore, knockdown of WFDC21P results in functional attenuation of miR-4293 on tumor promotion. In vivo xenograft growth is also promoted by both miR-4293 and WFDC21P. Overall, our results establish oncogenic roles for both miR-4293 and WFDC21P and demonstrate that interactions between miRNAs and lncRNAs through DCP2 are important in the regulation of carcinoma pathogenesis. These results provided a valuable theoretical basis for the discovery of lung carcinoma therapeutic targets and diagnostic markers based on miR-4293 and WFDC21P.

The role of single nucleotide polymorphisms of miRNAs 100 and 146a as prognostic factors for prostate cancer

INTRODUCTION

Prostate cancer has a high incidence in men and is the second cause of cancer death among americans male. microRNA (miR) is becoming a potential new prognostic factor for prostate cancer. Single nucleotide polymorphisms (SNPs) are common polymorphisms, characterized by a single exchange of nitrogen based in the DNA. This polymorphism is present in the miRs, altering their function.

OBJECTIVE

To evaluate the role of SNP rs1834306 of miR100 and rs2910164 of miR146a in the development and prognosis of prostate cancer.

METHODS

One hundred patients diagnosed with prostate cancer and 68 controls were selected. The identification of SNP was rated by quantitative polymerase chain reaction from blood samples, and the analysis was performed within the presence of SNP and the prognostic variables.

RESULTS

In the SNP rs1834306 (miR100), a smaller presence of the polymorphic homozygous genotype was identified in patients with PSA >10 ng/mL, (P=0.03); when evaluating only the presence of the polymorphic allele G (P=0.09) it was compared to the presence of the wild type allele A. Among the patients with prostate cancer, SNP rs2910164 (miR146A), the polymorphic allele was more frequent in patients with a Gleason score ⩾7 than in patients with a Gleason score <7, (P=0.043). In patients with prostate cancer, miR100 was overexpressed in those with pT3 staging compared to pT2 and among those who had biochemical recurrence (P = 0.004 and P = 0.011, respectively).

CONCLUSIONS

SNP of miR146a acts as a poor prognostic factor (Gleason ⩾7), and the SNP of miR100 is linked to better prognostic data (PSA <10). MiR100 was overexpressed in prostate cancer with worse prognostic factors.

miR-301b and NR3C2 co-regulate cells malignant properties and have the potential to be independent prognostic factors in breast cancer

This study intends to address the function of miR-301b/nuclear receptor subfamily 3 group C member 2 (NR3C2) in breast cancer. The Cancer Genome Atlas database was processed to investigate the expression of miR-301b/NR3C2 in breast cancer samples, as well as the relationship between their expression and the prognosis of the patients. Cox regression analysis was performed to determine whether miR-301b/NR3C2 was an independent predictor of the patient's prognosis. Associations between miR-301b and NR3C2 were analyzed by prediction website, dual-luciferase assay, and Pearson correlation coefficient. Quantitative polymerase chain reaction and Western blot analyses were implemented to detect gene expression. The relevant biological characteristics of MCF7 and BCAP-37 cells were tested by cell counting kit-8, colony formation, and transwell assays. Lower expression of NR3C2, which was closely related to the bad prognosis of breast cancer patients, was presented in breast cancer samples and can be used as an independent predictor. miR-301b, as an upstream regulator of NR3C2, was highly expressed in breast cancer samples and can be used as an independent predictor as well. Notably, a higher level of miR-301b and lower level of NR3C2 were related to the reduced overall survival in patients with breast cancer. The proliferative and migratory behaviors of cells were elevated or blocked after overexpression of miR-301b or NR3C2, respectively. However, the above situation was attenuated after together upregulation of miR-301b and NR3C2. The present data afforded evidence that miR-301b may be a tumor-promoting miRNA in breast cancer, and that miR-301b/NR3C2 axis mediated tumor development from cell proliferation and migration.

Association between Genetic Polymorphisms of miR-1307, miR- 1269, miR-3117 and Breast Cancer Risk in a Sample of South East Iranian Women

INTRODUCTION

MicroRNAs (miRNAs) play an essential role in the susceptibility and development of cancer cells.

OBJECTIVE

Examining the dependency of breast cancer risk with genetic polymorphisms of miR-1307, miR-1269, and miR-3117 in a sample of Iranian women (southeast region).

METHODS

The case-control study consisted of 520 individuals (260 diagnosed BC patients, 260 healthy individuals). The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used for genotyping of miR-1307 rs7911488, miR-1269 rs73239138, and miR-3117 (rs4655646 and rs7512692) polymorphisms.

RESULTS AND CONCLUSION

This study provided evidence that miR-1307 rs7911488 polymorphism significantly reduced the risk of BC in heterozygous AG genotype, as well as dominant (AG+GG) genotype and G allele. A significant correlation was found between dominant (AA+AG) genotype, the A allele and protection against BC due to miR-1269 rs73239138 in the sample of study. In contrast, our findings suggested that AG genotype and G allele of miR-3117 rs4655646 polymorphism could increase BC's susceptibility among the southeastern Iranian females. The miR-3117 rs7512692 variant also increased the risk of BC in codominant, dominant and recessive models, as well as the T allele. The possible dependency of miR-1307, miR-1269, and miR-3117 variants with patients' clinicopathological characteristics and BC was also studied. It was concluded that there is a correlation between miR-3117 rs7512692 variant and tumor grade (p=0.031); also, a correlation between miR-1269 rs73239138 variant and progesterone receptor status (p=0.006). The current investigation revealed that miR-1307, miR-1269, and miR-3117 polymorphisms might play a crucial role in the Iranian population's vulnerability to BC.<br />.

The associations and roles of microRNA single-nucleotide polymorphisms in cervical cancer

Cervical cancer is one of the fourth most common gynecological malignancies and has been identified as the fourth leading cause of cancer death in women worldwide. MicroRNAs (miRNAs) are single-stranded sequences of noncoding RNAs that are approximately 22-24 nucleotides in length. They modulate posttranscriptional mRNA expression and play critical roles in cervical cancer. Single nucleotide polymorphisms (SNPs) in miRNA genes may alter miRNA expression and maturation and have been associated with various cancers. This review mainly focuses on the roles of SNPs in miRNA genes in the development of cervical cancer and summarizes the research progress of miRNA SNPs in cervical cancer and their molecular regulation mechanisms.

16p11.2 microdeletion imparts transcriptional alterations in human iPSC-derived models of early neural development

Microdeletions and microduplications of the 16p11.2 chromosomal locus are associated with syndromic neurodevelopmental disorders and reciprocal physiological conditions such as macro/microcephaly and high/low body mass index. To facilitate cellular and molecular investigations into these phenotypes, 65 clones of human induced pluripotent stem cells (hiPSCs) were generated from 13 individuals with 16p11.2 copy number variations (CNVs). To ensure these cell lines were suitable for downstream mechanistic investigations, a customizable bioinformatic strategy for the detection of random integration and expression of reprogramming vectors was developed and leveraged towards identifying a subset of ‘footprint’-free hiPSC clones. Transcriptomic profiling of cortical neural progenitor cells derived from these hiPSCs identified alterations in gene expression patterns which precede morphological abnormalities reported at later neurodevelopmental stages. Interpreting clinical information—available with the cell lines by request from the Simons Foundation Autism Research Initiative—with this transcriptional data revealed disruptions in gene programs related to both nervous system function and cellular metabolism. As demonstrated by these analyses, this publicly available resource has the potential to serve as a powerful medium for probing the etiology of developmental disorders associated with 16p11.2 CNVs.

Downregulation of microRNA-605 indicates poor prognosis and promotes the progression of osteosarcoma

Osteosarcoma (OS) is a type of primary bone tumor, which is one of the leading causes of cancer-related death. MicroRNA (miR)-605 has been demonstrated to act as a prognostic biomarker and therapeutic target in various cancers, such as breast cancer and non-small cell lung cancer, but its function in OS remains unclear. The aim of the present study was to investigate the prognostic value of miR-605 in patients with OS by evaluating its expression levels and to explore the biological function of miR-605 in OS progression. For this purpose, tumor tissues and adjacent normal tissues were collected from OS patients, and the expression of miR-605 in the collected tissues and OS MG63, U2OS, HOS, and SAOS-2 cell lines was detected by quantitative real-time PCR. The prognostic value of miR-605 was evaluated by Kaplan-Meier survival curves and Cox regression analysis. The effects of miR-605 on OS cell proliferation, migration and invasion were analyzed by the CCK-8 and transwell assays, respectively. The results of the present study revealed that miR-605 was significantly downregulated in OS tissues compared with adjacent normal tissues, which was associated with the clinical stage and distant metastasis of patients. Additionally, the downregulation of miR-605 predicted the poor prognosis of patients with OS and served as an independent prognostic indicator. The downregulation of miR-605 enhanced cell proliferation, migration, and invasion of OS cells, which suggested that miR-605 may be involved in the progression of OS. The findings of the present study provide a new therapeutic target for the treatment of patients with OS.

Evaluating the Possible Association between PD-1 (Rs11568821, Rs2227981, Rs2227982) and PD-L1 (Rs4143815, Rs2890658) Polymorphisms and Susceptibility to Breast Cancer in a Sample of Southeast Iranian Women

INTRODUCTION

Programmed cell death-1 (PD-1) and its ligands (PD-L1 and PD-L2) play a critical role as a  regulator of immune-system cells, including T cell, natural killer T (NKT), monocytes, dendritic cells (DC), and B cells.

OBJECTIVE

This study aimed to find a possible association between PD-1 (rs11568821, rs2227981, rs2227982), and PD-L1 (rs4143815, rs2890658) variants and Breast Cancer (BC) risk in a sample of southeast Iranian women.

METHOD

The case-control study consisted of 520 individuals, including 260 histologically confirmed BC patients and 260 non-cancer age-matching healthy women as the control group. The Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and Tetra-Primer Amplification Refractory Mutation System-Polymerase Chain Reaction (T-ARMS-PCR) methods were used for genotyping of PD-1 (rs11568821, rs2227981, rs2227982), and PD-L1 (rs4143815, rs2890658) polymorphisms.

RESULTS AND CONCLUSION

Our findings indicated that the PD-L1 rs4143815 (G/C) variant meaningfully reduced the risk of BC. However, the PD-L1 rs2890658 variant increased the BC risk in the AC genotype as well as the A allele. Furthermore, we could not find a meaningful association between PD-1 rs11568821, PD-1 rs2227981, PD-1 rs2227982, and BC. Our team examined the possible association between variants and clinicopathological characteristics, including age, size of tumour, lymph node, histology, grade of tumour, estrogen and progesterone receptors status as well as human growth factor receptor 2 (HER2). Our findings demonstrated that PD-L1 rs4143815, PD-L1 rs2890658, PD-1 rs2227982 had a significant association with age. Additionally, we found a significant relation between PD-1 rs2227982 variant and tumour size. Statistical analyzes of PD-1 rs2227981 and PD-1 rs11568821 variants showed a meaningful relation between tumour grade and tumour stage (p=0.006), respectively.<br />.

miR-100 rs1834306 A>G Increases the Risk of Hirschsprung Disease in Southern Chinese Children

Background

Hirschsprung disease (HSCR) is a rare congenital gastrointestinal disease characterized by the absence of intestinal submucosal and myometrial ganglion cells. Recently, researches indicated that miR-100 regulated the growth, differentiation and apoptosis of neurons, and affected the functions of HSCR-associated pathways. While miR-100 rs1834306 A>G polymorphism was shown to modify the susceptibility to tumors, the association between this polymorphism and HSCR susceptibility is still unknown.

Methods

This was a case-control study consisting of 1470 HSCR cases and 1473 controls from southern China. DNA was genotyped by TaqMan real-time PCR. Odds ratios (ORs) and 95% confidence intervals (CIs) were used as statistical indicators.

Results

We found that miR-100 rs1834306 G allele and GG genotype significantly increased HSCR susceptibility (GG vs AA: adjusted OR=1.31, 95% CI=1.04-1.64, P=0.020; G vs A: adjusted OR=1.12, 95% CI=1.01-1.25, P=0.041; GG vs AA/AG: adjusted OR=1.30, 95% CI=1.07-1.59, P=0.010). In the stratified analysis, miR-100 rs1834306 GG genotype carriers had higher risk to develop HSCR in all clinical subtypes when compared with those with AA/AG genotypes, and OR was rising with HSCR aggravation (SHSCR: adjusted OR=1.28, 95% CI=1.03-1.59, P=0.029; LHSCR: adjusted OR=1.48, 95% CI=1.06-2.07, P=0.020; TCA: adjusted OR=2.12, 95% CI=1.22-3.69, P=0.008).

Conclusion

Our findings suggested that miR-100 rs1834306 A>G polymorphism was associated with increased HSCR susceptibility in southern Chinese children. Furthermore, miR-100 rs1834306 GG genotype had a greater genetic pathopoiesis in severe HSCR.

Association of miR-4293 rs12220909 polymorphism with cancer risk: A meta-analysis of 8394 subjects

BACKGROUND

Several studies have investigated miR-4293 rs12220909 polymorphisms and cancer susceptibility and yielded different results. Because of this controversy, we designed a meta-analysis to assess comprehensively the association of the rs12220909 polymorphism with cancer risk.

METHODS

Relevant articles were collected by searching the databases of PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and WanFang. Data on rs12220909 in cancer patients and controls were extracted. Sensitivity analyses and publication bias assessments were performed.

RESULTS

Five studies with 3820 cases and 4574 controls were included in our meta-analysis. Pooled analyses showed that the rs12220909 polymorphism was not associated with cancer risk in any genetic model. (C vs G: odds ratio [OR] = 0.89, 95% confidence interval [CI] = 0.74-1.07; GC vs GG: OR = 0.83, 95% CI = 0.67-1.03; CC vs GG: OR = 1.06, 95% CI = 0.82-1.36; CC+GC vs GG: OR = 0.84, 95% CI = 0.69-1.03; CC vs GC+GG: OR = 1.10, 95% CI = 0.85-1.40).

CONCLUSIONS

Our results indicate that rs12220909 is not associated with cancer risk. Larger, well-designed multicenter studies are needed to further explore the association of miR-4293 rs12220909 polymorphism with cancer risk.

Whether miR-4293 rs12220909 variant affects cancer susceptibility: evidence from 11255 subjects

Background: miR-4293 rs12220909 polymorphism was reported associated with tumorigenesis, but the results are controversial. Thus, we planned to verify and obtain precise results.Methods: Databases were searched and reviewed up to November, 2019. Case-control studies which concern about the association between cancer risks and miR-4293 polymorphisms were all enrolled. The odds ratios (ORs) and 95% confidence intervals (CIs) calculated by the Z test were used to assess the underlying links. We also prospected how the miR-4293 impacts biological process through its target genes.Result: Finally, there are seven independent studies meet the enrolled criteria, along with 5147 cases and 6108 healthy controls. We revealed that there is a significant decrease effect of miR-4293 rs12220909 to cancer risks in heterozygote genetic model (BA vs. AA: OR = 0.857, p = .032), the similar results were also uncovered in PB control group, lung cancer and the studies conform to HWE. Results from GO items and KEGG pathway analysis illustrated that myeloid cell development, transcription factor complex, RNA polymerase II regulatory region DNA binding were regulated by miR-4293.Conclusion: In summary, our meta-analysis chase down heterozygote rs12220909 polymorphism of miR-4293 is a protective factor to cancer initiation, especially for lung cancer.

Evaluation of the Role of hsa-mir-124 in Predicting Clinical Outcome in Breast Invasive Carcinoma Based on Bioinformatics Analysis

Purpose

Breast invasive carcinoma (BRCA) is the most common malignant tumor. MiR-124 plays a tumor-suppressive role in human cancer. However, the clinical significance of miR-124 in BRCA remains unclear. The aim of this study was to evaluate the association of hsa-mir-124 expression and the clinicopathological characteristics in BRCA using database analysis.

Methods

The clinical data and expression profiles of hsa-mir-124 were obtained from the cancer genome atlas for BRCA (TCGA_BRCA). Then, the prognostic value of hsa-mir-124 in BRCA was investigated using the Cox Regression test, and the association of hsa-mir-124 and pathology TNM stages and pathologic stages were measured by the Kruskal–Wallis test and Wilcox. test. In addition, the association of hsa-mir-124 and tumor molecular phenotypes was performed using the Chi-Square test.

Results

We found that the overall survival of patients with high expression of hsa-mir-124-1 and hsa-mir-124-2 was better than that of patients with low expression of hsa-mir-124-1 and hsa-mir-124-2. And the expression of hsa-mir-124-1, hsa-mir-124-2, and hsa-mir-124-3 was mainly enriched in T1/T2 stages, NO/N1 stages, and M0 stages. Then, the expression of hsa-mir-124-1, hsa-mir-124-2, and hsa-mir-124-3 was negatively associated with tumor lymph node metastasis. Moreover, the expression of hsa-mir-124 was associated with tumor molecular phenotype in breast invasive carcinoma.

Conclusion

Our findings indicated that hsa-mir-124 expressions were associated with overall survival, TNM stages, pathologic characteristics, and tumor molecular phenotype in BRCA via TCGA_BRCA database, providing a new biomarker and a potential therapeutic target for BRCA patients.

MiR-218 and miR-100 polymorphisms as markers of irinotecan-based chemotherapy response in metastatic colorectal cancer

PURPOSE

Colorectal cancer is the fourth cause of cancer-related death. Drug toxicity and resistance remain concerns of major importance. miR-100 and miR-218 are micro-RNAs that regulate cellular proliferation, differentiation and apoptosis acting as oncogenes and tumour suppressors; their functions and have been linked with toxicity development and drug resistance.

METHODS

We investigated the correlation between rs11134527 miR-218 and rs1834306 miR-100 polymorphisms and irinotecan-based regimens with regard to drug efficacy and toxicity. A total of 105 mCRC patients receiving irinotecan-based regimens were included in our study and assessed in terms of toxicity development and response to treatment. Rs11134527 miR-218 and rs1834306 miR-100 polymorphism genotyping in the peripheral blood was performed with PCR-RFLP.

RESULTS

Neither rs11134527 miR-218 nor rs1834306 miR-100 are associated with toxicity risk to treatment regimens. GA/AA genotypes of rs11134527 and CT/TT genotypes of rs1834306 were associated with a significantly reduced time-to-progression (TTP) and overall survival (OS).

CONCLUSIONS

GA/AA genotypes of rs11134527 miR-218 and CT/TT genotypes of rs1834306 miR-100 polymorphisms could serve as prognostic biomarkers of TTP and OS. Carriers of the A allele of the miR-218 rs11134527 and T allele of the miR-100 rs1834306 polymorphisms are more likely not to respond to irinotecan-based therapies. However, further studies in larger patient populations are required.

Evidences from a Systematic Review and Meta-Analysis Unveil the Role of MiRNA Polymorphisms in the Predisposition to Female Neoplasms

Breast (BCa) and gynecological (GCa) cancers constitute a group of female neoplasms that has a worldwide significant contribution to cancer morbidity and mortality. Evidence suggests that polymorphisms influencing miRNA function can provide useful information towards predicting the risk of female neoplasms. Inconsistent findings in the literature should be detected and resolved to facilitate the genetic screening of miRNA polymorphisms, even during childhood or adolescence, and their use as predictors of future malignancies. This study represents a comprehensive systematic review and meta-analysis of the association between miRNA polymorphisms and the risk of female neoplasms. Meta-analysis was performed by pooling odds-ratios (ORs) and generalized ORs while using a random-effects model for 15 miRNA polymorphisms. The results suggest that miR-146a rs2910164 is implicated in the susceptibility to GCa. Moreover, miR-196a2 rs11614913-T had a moderate protective effect against female neoplasms, especially GCa, in Asians but not in Caucasians. MiR-27a rs895819-G might pose a protective effect against BCa among Caucasians. MiR-499 rs3746444-C may slightly increase the risk of female neoplasms, especially BCa. MiR-124 rs531564-G may be associated with a lower risk of female neoplasms. The current evidences do not support the association of the remaining polymorphisms and the risk of female neoplasms.

Epigenetic Drugs for Cancer and microRNAs: A Focus on Histone Deacetylase Inhibitors

Over recent decades, it has become clear that epigenetic abnormalities are involved in the hallmarks of cancer. Histone modifications, such as acetylation, play a crucial role in cancer development and progression, by regulating gene expression, such as for oncogenes or tumor suppressor genes. Therefore, histone deacetylase inhibitors (HDACi) have recently shown efficacy against both hematological and solid cancers. Designed to target histone deacetylases (HDAC), these drugs can modify the expression pattern of numerous genes including those coding for micro-RNAs (miRNA). miRNAs are small non-coding RNAs that regulate gene expression by targeting messenger RNA. Current research has found that miRNAs from a tumor can be investigated in the tumor itself, as well as in patient body fluids. In this review, we summarized current knowledge about HDAC and HDACi in several cancers, and described their impact on miRNA expression. We discuss briefly how circulating miRNAs may be used as biomarkers of HDACi response and used to investigate response to treatment.

The Relationship between Pre-miR-3131 3-bp Insertion/Deletion Polymorphism and Susceptibility and Clinicopathological Characteristics of Patients with Breast Cancer

Aims

This study aimed at examining the effect of 3-bp pre-miR-3131 insertion/deletion (ins/del) polymorphism on Breast Cancer (BC) risk.

Objectives

Totally 403 women including 199 BC patients and 204 women who have no cancer were included in this case-control study. Genotyping of miR-3131 3-bp ins/del polymorphism was performed by mismatch PCR-RFLP method.

Methods

The findings expressed that the pre-miR-3131 3-bp ins/del variant was not related to the risk of BC in all genetic tested models. While, the ins/del genotype was related to late onset BC (OR=2.53, 95%CI=1.27-4.84, p=0.008).

Results

Pooled results from the meta-analysis indicated to that the pre-miR-3131 ins/del is related to with an increased risk of cancer in heterozygous (OR=1.26, 95%CI=1.06-1.51, p=0.01), dominant (OR=1.33, 95%CI=1.14-1.54, p=0.0002), and allele (OR=1.24, 95%CI=1.06-1.45, p=0.006) genetics models.

Conclusion

It is concluded that, our findings did not support a relationship between pre-miR-3131 ins/del polymorphism and the risk of BC. While, this variant was significantly related to late onset BC. Combined results of this study with previous studies indicated that this polymorphism increased the risk of cancer. More studies in a study with larger population with variety of ethnicities are required to verify our findings.

Genetic and molecular biology of breast cancer among Iranian patients

Abstract

Background, Breast cancer (BC) is one of the leading causes of cancer related deaths in Iran. This high ratio of mortality had a rising trend during the recent years which is probably associated with late diagnosis.

Main body

Therefore it is critical to define a unique panel of genetic markers for the early detection among our population. In present review we summarized all of the reported significant genetic markers among Iranian BC patients for the first time, which are categorized based on their cellular functions.

Conclusions

This review paves the way of introducing a unique ethnic specific panel of diagnostic markers among Iranian BC patients. Indeed, this review can also clarify the genetic and molecular bases of BC progression among Iranians.

Association between CASP3 polymorphisms and overall cancer risk: A meta-analysis of case-control studies

Several studies inspected the relationship between caspase-3 (CASP3) polymorphisms and the risk of several human cancers, but the findings remain controversial. We conducted a meta-analysis aiming to inspect the association between CASP3 rs1049216 T>C, rs12108497 C>T, rs4647603 G>A, rs4647602 C>A, rs6948 T>G, rs2705897 A>C, and rs113420705 G>A polymorphisms and cancer risk. Eligible studies were recognized by searching the Web of Science, PubMed, Scopus, and Google Scholar databases. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to quantitatively evaluate the association between each polymorphism of CASP3 and cancer risk. The rs4647603 variant significantly increased the risk of cancer in an overdominant (OR, 1.44; 95% CI, 1.03-2.01; P = 0.03; AG vs AA+GG) inheritance model. Regarding the rs4647602 variant, the findings revealed that this variant was associated with protection against cancer in homozygous codominant (OR, 0.67; 95% CI, 0.56-0.80; P < 0.00001; AA vs CC), dominant (OR, 0.84; 95% CI, 0.73-0.96; P = 0.009; AC+AA vs CC), recessive (OR, 0.70; 95% CI, 0.61-0.79; P < 0.00001; AA vs AC+CC), and allele (OR, 0.81; 95% CI, 0.75-0.88; P = 0.00001; A vs C) models. The findings suggested that the rs2705897 variant significantly decreased the risk of cancer in heterozygous codominant (OR, 0.80; 95% CI, 0.67-0.94; P = 0.009; AC vs AA), dominant (OR, 0.81; 95% CI, 0.69-0.95; P = 0.009; AC+CC vs AA), overdominant (OR, 0.80; 95% CI, 0.68-0.95; P = 0.01; AC vs CC+AA), and allele (OR, 0.85; 95% CI, 0.74-0.97; P = 0.02; C vs A) models. The results did not support an association between CASP3 rs1049216 and rs6948 polymorphisms and cancer risk. In summary, the findings of this meta-analysis support an association between CASP3 polymorphisms and cancer risk. Larger and well-designed studies are desired to evaluate these associations in detail.

Expression and correlation of miR-124 and miR-126 in breast cancer

The expression of micro ribonucleic acid (miR)-124 and miR-126 in different stages of breast cancer (BC) and their correlation were investigated to analyze the role of miR-124 and miR-126 in the occurrence and development of BC. BC tissues of 83 BC patients treated in First Teaching Hospital of Tianjin University of Traditional Chinese Medicine from March 2016 to January 2018 were selected as the research group, while the corresponding para-carcinoma normal tissues were selected as the control group. The relative expression levels of miR-124 and miR-126 in both groups were detected via reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and the miR-124 and miR-126 expression asociated with clinicopathological parameters of patients and the correlation between miR-124 and miR-126 was analyzed. The relative expression levels of miR-124 and miR-126 in the research group were significantly lower than those in the control group (P<0.001). miR-124 and miR-126 in the research group were associated with clinicopathological parameters (clinical stage, degree of pathological differentiation and lymph node metastasis) of patients (P<0.001). According to Pearsons correlation analysis, there was a positive correlation between the relative expression levels of miR-124 and miR-126 in cancer tissues (r=0.497, P<0.001). The expression levels of miR-124 and miR-126 were downregulated in BC tissues, which were associated with clinicopathological parameters (clinical stage, degree of pathological differentiation and lymph node metastasis). There was a positive correlation between the expression levels of miR-124 and miR-126 in BC tissues. Thus, miR-124 and miR-126 may be involved in the occurrence, development, invasion and metastasis of BC, and both can be used as targeted biological indexes for treatment of BC.

Association between miR-218 rs11134527 polymorphism and risk of selected types of cancer in Asian population: An updated meta-analysis of case-control studies

Several studies inspected the relationship between miR-218 rs11134527 polymorphism and the risk of some human cancers, but the findings remains controversial. We designed an update meta-analysis aiming to validate the association between rs11134527 polymorphism of miR-218 and cancer risk. Eligible studies including 7989 cancer cases and 8761 controls were recognized by searching Web of Science, PubMed, Scopus, and Google scholar databases. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to quantitatively evaluate the association between rs11134527 variant and cancer risk. The overall results indicated no significant relationship between miR-218 rs11134527 polymorphism and cancer risk in codominant, dominant, recessive, overdominant, and allele inheritance model tested. Stratified analysis showed that rs11134527 variant significantly increased the risk of developing esophageal squamous cell carcinoma (ESCC) in heterozygous codominant (OR = 1.32, 95%CI = 1.03-1.69, p = 0.03, AG vs GG) inheritance model. In summary, the findings of this meta-analysis did not support an association between miR-218 rs11134527 polymorphism and cancer risk. Stratified analysis showed that rs11134527 variant significantly increased the risk of developing ESCC. Larger and well-designed researches are needed to estimate this association in detail.

Lack of Association between miR-605 rs2043556 Polymorphism and Overall Cancer Risk: A Meta-analysis of Case-control Studies

Growing evidence propose an association between miRNA polymorphisms and cancer susceptibility. This study aimed to examine the impact of miR-605 rs2043556 polymorphism on cancer risk through a meta-analysis based on 3198 cancer cases and 4943 controls. Eligible studies were retrieved by searching Web of Science, PubMed, Scopus, and Google Scholar databases up to August 27, 2018. The pooled Odds Ratios (ORs) with 95% Confidence Intervals (CIs) were calculated using a random-effect model to estimate the strength of association between rs2043556 variant of miR-605 and cancer risk. Overall, no significant association was found between miR-605 rs2043556 polymorphism and cancer risk in heterozygous codominant (OR=0.93, 95% CI=0.76-1.13, p=0.44, AG vs. AA), homozygous codominant (OR=1.01, 95%CI=0.78-1.30, p=0.94, GG vs. AA), dominant (OR=0.95, 95% CI=0.79-1.13, p=0.55, AG+GG vs. AA), recessive (OR=1.07, 95%CI=0.84-1.38, p=0.57, GG vs. AG+AA), overdominant (OR=0.93, 95% CI=0.76-1.12, p=0.43, AG vs. GG+AA), and allele (OR=0.98, 95% CI=0.87-1.10, p=0.73, G vs. A) genetic models tested. Stratified analysis by cancer type revealed that the rs2043556 variant was not associated with digestive tract cancer, breast cancer, gastric cancer as well as lung cancer. Taken together, the findings of this meta-analysis did not support an association between miR-605 rs2043556 polymorphism and cancer susceptibility.

Mechanism of the enhancing effects of miR-93 on resistance of breast cancer MCF-7 cells to adriamycin

This study aimed to investigate the effects of miR-93 on resistance of breast cancer MCF-7 cells to adriamycin, and to explore the possible mechanism. Expression of miR-93 in breast cancer cell lines MCF-7 and MCF-7/ADM was detected by reverse transcription-quantitative PCR (RT-qPCR). miR-93 mimics and inhibitors were transfected into MCF-7/ADM and MCF-7 cells, and MTT assay was used to detect the resistance of cells to adriamycin after transfection. Western blot analysis was used to detect the expression of anti-apoptotic protein Bcl-2 and multidrug resistance gene MDR1 related P-gp protein in MCF-7/ADM and MCF-7 cells before and after the transfection of miR-93 mimics. Expression level of miR-93 in MCF-7/ADM cells was decreased, and was 40% of that in MCF-7 cells (0.39±0.04, p<0.05). Before transfection, IC₅₀ value of MCF-7 cells to adriamycin (11.02±0.95) was lower than that of MCF-7/ADM cells (21.29±1.83, p<0.05). IC₅₀ value of MCF-7/ADR cells at 72 h after transfection with miR-93 mimics (13.55±0.86) was lower than that of the negative control group (24.67±1.51, p<0.05). IC₅₀ value of MCF-7 cells 72 h after transfection with miR-93 inhibitor (19.88±1.28) was higher than that of negative control group (11.02±0.95, p<0.05). Expression levels of Bcl-2 and P-gp proteins in MCF-7/ADM cells were 1.63±0.24 and 1.76±0.22 times that of MCF-7 cells, respectively (p<0.05). At 72 h after transfection of miR-93 mimics, expression levels of Bcl-2 and P-gp proteins in MCF-7/ADM cells were 0.27±0.06 and 0.39±0.05, respectively, compared with the negative control group (p<0.05). At 72 h after transfection with miR-93 inhibitor, expression levels of Bcl-2 and P-gp protein in MCF-7 cells were 1.48±0.10 and 1.56±0.11 times of the negative control group, respectively (p<0.05). miR-93 can increase the apoptosis of MCF-7/ADM cells and their resistance to adriamycin by inhibiting the expression of Bcl-2 and P-gp proteins.

Association between miR-124-1 rs531564 polymorphism and risk of cancer: An updated meta-analysis of case-control studies

Many studies examined the association between miR-124-1 rs531564 polymorphism and the risk of some human cancers, but the findings remain controversial. This update meta-analysis aimed to validate the association between rs531564 polymorphism of miR-124-1 and cancer risk. Eligible studies including 6,502 cancer cases and 7,213 controls were documented by searching Web of Science, PubMed, Scopus, and Google scholar databases. Pooled odds ratios (ORs) with 95 % confidence intervals (CIs) were estimated to quantitatively evaluate the association between rs531564 variant and cancer risk. The results indicated that rs531564 variant significantly decreased the risk of cancer in homozygous codominant (OR=0.54, 95 % CI=0.43-0.69, p<0.00001, GG vs CC), dominant (OR=0.84, 95 % CI=0.72-0.99, p=0.03, CG+GG vs CC), recessive (OR=0.65, 95 % CI=0.54-0.78, p<0.00001, GG vs CG+CC), and allele (OR=0.84, 95 % CI=0.73-0.96, p=0.008, G vs C) genetic model. Stratified analysis by cancer type revealed that rs531564 variant was associated with gastric cancer, cervical cancer, esophageal squamous cell carcinoma and colorectal cancer risk. In summary, the findings of this meta-analysis support an association between miR-124-1 rs531564 polymorphism and cancer risk. Larger and well-designed studies are required to estimate this association in detail.