Effects of miR-27a, miR-196a2 and miR-146a polymorphisms on the risk of breast cancer

Association analysis of miRNA-146a and miRNA-196a polymorphism with breast cancer risk in Khyber Pakhtunkhwa, Pakistan: a preliminary study

BACKGROUND

microRNAs (miRNAs) are small, noncoding RNA molecules, functioning either as oncogenes or tumor suppressor genes. SNPs in miRNAs might modify the expression of genes associated with miRNAs, enhancing susceptibility to breast cancer. Both miRNA-146a (rs2910164) and miRNA-196a (rs11614913) are identified and significantly associated with breast cancer risk in several ethnicities, but remains unexplored in Khyber Pakhtunkhwa population of Pakistan.

METHODS

This study was aimed to check the relation of selected SNPs with breast cancer risk. The research cohort included 100 breast cancer patients and 100 healthy controls. All the participants were subjected for DNA extraction followed by T-ARMS PCR and gel electrophoresis.

RESULTS

The results revealed a strong association between risk allele (G) of miRNA-146a and increased risk of breast cancer (OR = 2.04, P = 0.0006). Similarly, heterozygous and mutant genotypes also indicated high risk and significant association with breast cancer risk (CG; OR = 0.51, 9 P = 0.0001) (GG; OR = 3.76, P = 0.04). However, risk allele (T) of miRNA-196a (rs11614913) failed to exhibit significant association with breast cancer risk (OR = 0.92 P = 0.68). Similarly, the heterozygous and mutant genotype did not show significant association with breast cancer risk (CT; OR = 0.52, P = 0.125 (TT; OR = 0.88, P = 0.84). Furthermore, miRNA-146a (rs2910164) and miRNA-196a (rs11614913) polymorphisms exhibited non-significant associations with family history (P = 0.34, P = 0.77), PR status (P = 0.310, P = 0.397), ER status (P = 0.992, P = 0.981), nodal status (P = 0.86, P = 0.90), and menstrual status (P = 0.97, P = 0.09). Notably, miRNA-196a showed a significant association with the metastasis group (P = 0.010) and cancer stages (P = 0.047).

CONCLUSIONS

In conclusion, this study highlights the association of miRNA-146a (rs2910164) polymorphism with breast cancer risk but suggested non-significant association of miRNA-196a (rs11614913) with breast cancer risk. However, these findings need to be confirmed through larger data set for more accurate result.

Comprehensive Molecular Evaluation of HNF-1 Alpha, miR-27a, and miR-146 Gene Variants and Their Link with Predisposition and Progression in Type 2 Diabetes Patients

BACKGROUND

Type 2 diabetes (T2D) is a metabolic condition induced by insulin resistance and pancreatic beta cell dysfunction. MicroRNAs (miRNAs) have biological significance because they regulate processes such as the molecular signaling pathways involved in the pathophysiology of diabetes mellitus. The hepatocyte nuclear factor-1 alpha (HNF-1 alpha) is a transcription factor found in hepatocytes and the pancreas. Mutations in the HNF-1 alpha gene were reportedly associated with maturity-onset diabetes of the young (MODY). The objective of the present study was to examine the associations between MiR-27a, MiR-146, and HNF-1 alpha single-nucleotide variations (SNVs) with T2D risk in the Saudi population.

METHODOLOGY

We evaluated the association of SNVs of miR-27a rs895819 A>G, 146a-rs2910164 C>G, and HNF-1 alpha rs1169288 G>T (I27L) with the risk of T2D in Saudi patients with the Amplification Refractory Mutation System PCR (ARMS-PCR). For the miR-27a SNVs, we used 115 cases (82 males, 33 females) and 117 matched healthy controls (HCs); for the Mir-146 SNVs, we used 103 cases (70 males, 33 females) and 108 matched HCs; and for the HNF-1 alpha, we employed 110 patients (80 males, 30 females) and 110 HCs. The blood biochemistry of the participants was essayed using commercial kits, and the methods of statistical analysis used were the Chi-square test, the Fisher exact test, and a multivariate analysis based on logistic regression, like the odds ratio (OD) and risk ratio (RR), with 95% confidence intervals (CIs).

RESULTS

The MiR-27a rs895819 AG genotype was linked to increased T2D susceptibility, with OR = 2.01 and p-value = 0.011, and the miR-146 rs2910164 CG genotype and C allele were linked to an elevated risk of T2D, with OR = 2.75, p-value < 0.0016, OR = 1.77, and p-value = 0.004. The results also showed that the GT genotype and T allele of the HNF-1 alpha (rs1169288) G>T is linked to T2D, with OR = 2.18, p-value = 0.0061, and 1.77, p-value = 0.0059.

CONCLUSIONS

The SNVs in miR-27a, miR-146, and HNF-1 alpha can be potential loci for T2D risk. The limitations of this study include the relatively small sample size and the fact that it was a cross-sectional study. To our knowledge, this is the first study to highlight the association between miR-27a, miR-146, and HNF-1 alpha SNVs and the risk of T2D in the Saudi population. Future large-scale case-control studies, as well as studies on the functions of the proteins and protein interaction studies for HNF-1 alpha, are required to verify our findings. Furthermore, these findings can be used for the identification and stratification of at-risk populations via genetic testing for T2D-prevention strategies.

Functional Variants in MicroRNAs (rs895819, rs11614913 and rs2910164) Are Associated with Susceptibility and Clinicopathological Features in Mexican Patients with Colorectal Cancer

BACKGROUND

miRNAs are non-coding RNAs participating actively in the post-translational regulation of oncogenes, tumor suppressor, and DNA repair genes implicated in colorectal cancer (CRC). This study aims to examine the association of the variants miR-27a (rs895819 A>G), miR-196a2 (rs11614913 T>G) and miR-146a (rs2910164 C>G) in Mexican CRC patients.

METHODS

DNA samples from 183 patients and 186 healthy Mexican subjects were analyzed. Variants were identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology. Association was calculated by the odds ratio (OR) and adjusted by the Bonferroni test.

RESULTS

Patients carrying the G/G genotype of the rs895819 variant in the miR-27a gene showed an increased risk of CRC (19% vs 12%, P=0.013). A similar tendency was noticed for patients younger than 50 years carrying A/G (48% vs 41%, P=0.014). The A/G genotype in TNM stages I+II (55.7% vs 40.8%, P=0.011) and tumor location in the colon (69.5 vs 40.8%, P=0.001) were also increased. For the variant rs11614913 of the miR-196a2 gene, carriers of the C/C genotype showed an increased risk of CRC (32% vs 22%, P=0.009). This genotype was more frequent in TNM stage III+IV (36.8% vs 22.5%, P=0.007) and the tumor had a more recurrent location in the rectum (31.6% vs 22.5%, P=0.013). The rs2910164 variant of the miR-146a gene was found to have no significant risk associations.

CONCLUSION

Our results reveal that the rs895819 variant in miR-27a and rs11614913 in miR-196a2 have a substantial impact on the development of CRC.

Potential Impact of PI3K-AKT Signaling Pathway Genes, KLF-14, MDM4, miRNAs 27a, miRNA-196a Genetic Alterations in the Predisposition and Progression of Breast Cancer Patients

Genome-wide association studies have reported link between SNPs and risk of breast cancer. This study investigated the association of the selected gene variants by predicting them as possible target genes. Molecular technique advances with the availability of whole-exome sequencing (WES), now offer opportunities for simultaneous investigations of many genes. The experimental protocol for PI3K, AKT-1, KLF-14, MDM4, miRNAs 27a, and miR-196a genotyping was done by ARMS-PCR and sanger sequencing. The novel and known gene variants were studied by Whole-exome sequencing using Illumina NovaSeq 6000 platform. This case control study reports significant association between BC patients, healthy controls with the polymorphic variants of PI3K C > T, AKT-1 G > A KLF 14 C > T, MDM4 A > G, miR-27a A > G, miR-196a-2 C > T genes (p < 0.05). MDM4 A > G genotypes were strongly associated with BC predisposition with OR 2.08 & 2.15, p < 0.05) in codominant and dominant models respectively. MDM4 A allele show the same effective (OR1.76, p < 0.05) whereas it remains protective in recessive model for BC risk. AKT1G > A genotypes were strongly associated with the BC susceptibility in all genetic models whereas PI3K C > T genotypes were associated with breast cancer predisposition in recessive model OR 6.96. Polymorphic variants of KLF-14 A > G, MDM4G > A, MiR-27aA >G, miR-196a-C > T were strongly associated with stage, tamoxifen treatment. Risk variants have been reported by whole exome sequencing in our BC patients. It was concluded that a strong association between the PI3K-AKT signaling pathway gene variants with the breast cancer susceptibility and progression. Similarly, KLF 14-AA, MDM4-GA, miR27a-GG and miR-196a-CT gene variants were associated with the higher risk probability of BC and were strongly correlated with staging of the BC patients. This study also reported Low, novel, and intermediate-genetic-risk variants of PI3K, AKT-1, MDM4G & KLF-14 by utilizing whole-exome sequencing. These variants should be further investigated in larger cohorts' studies.

Pleiotropic effects of DCLK1 in cancer and cancer stem cells

Doublecortin-like kinase 1 (DCLK1), a protein molecule, has been identified as a tumor stem cell marker in the cancer cells of gastrointestinal, pancreas, and human colon. DCLK1 expression in cancers, such as breast carcinoma, lung carcinoma, hepatic cell carcinoma, tuft cells, and human cholangiocarcinoma, has shown a way to target the DCLK1 gene and downregulate its expression. Several studies have discussed the inhibition of tumor cell proliferation along with neoplastic cell arrest when the DCLK1 gene, which is expressed in both cancer and normal cells, was targeted successfully. In addition, previous studies have shown that DCLK1 plays a vital role in various cancer metastases. The correlation of DCLK1 with numerous stem cell receptors, signaling pathways, and genes suggests its direct or an indirect role in promoting tumorigenesis. Moreover, the impact of DCLK1 was found to be related to the functioning of an oncogene. The downregulation of DCLK1 expression by using targeted strategies, such as embracing the use of siRNA, miRNA, CRISPR/Cas9 technology, nanomolecules, specific monoclonal antibodies, and silencing the pathways regulated by DCLK1, has shown promising results in both in vitro and in vivo studies on gastrointestinal (GI) cancers. In this review, we will discuss about the present understanding of DCLK1 and its role in the progression of GI cancer and metastasis.

Association of Polymorphisms in miR146a, an Inflammation-Associated MicroRNA, with the Risk of Idiopathic Recurrent Spontaneous Miscarriage: A Case-Control Study

It has been established that microRNAs (miRNAs) are involved in the regulation of immune responses and serve as biomarkers of inflammatory diseases as well as recurrent spontaneous miscarriage (RSM). Herein, we aimed to study the relationship between three functional miR146a gene polymorphisms with idiopathic RSM (IRSM) susceptibility. We recruited 161 patients with IRSM and 177 healthy women with at least one live birth and without a history of abortion. Genotyping was performed using RFLP-PCR and ARMS-PCR methods. We found that the rs6864584 T/C decreased the risk of IRSM under dominant TT+TC vs. CC (OR = 0.029) and allelic C vs. T (OR = 0.028) contrast models. Regarding rs2961920 A/C and rs57095329 A/G polymorphisms, the enhanced risk of IRSM was observed under different genetic contrasted models, including the codominant CC vs. AA (OR = 2.81 for rs2961920) and codominant GG vs. AA (OR = 2.36 for rs57095329). After applying a Bonferroni correction, haplotype analysis revealed a 51% decreased risk of IRSM regarding the ACA genotype combination. This is the first study reporting that miR146a rs57095329 A/G, rs2961920A/C, and rs6864584 T/C polymorphisms are associated with the risk of IRSM in a southern Iranian population. Performing replicated case-control studies on other ethnicities is warranted to outline the precise effects of the studied variants on the risk of gestational trophoblastic disorders.

Genetic Variants of MIR27A, MIR196A2 May Impact the Risk for the Onset of Coronary Artery Disease in the Pakistani Population

Genetic variants in microRNA genes have a detrimental effect on miRNA-mediated regulation of gene expression and may contribute to coronary artery disease (CAD). CAD is the primary cause of mortality worldwide. Several environmental, genetic, and epigenetic factors are responsible for CAD susceptibility. The contribution of protein-coding genes is extensively studied. However, the role of microRNA genes in CAD is at infancy. The study is aimed to investigate the impact of rs895819, rs11614913, and rs2168518 variants in MIR27A, MIR196A2, and MIR4513, respectively, in CAD using allele-specific PCR. Results: For variant rs11614913, significant distribution of the genotypes among the cases and controls was determined by co-dominant [χ² = 54.4; p value ≤ 0.0001], dominant (C/C vs. C/T + T/T) [OR = 0.257 (0.133-0.496); p value ≤ 0.0001], recessive (T/T vs. C/T + C/C) [OR = 1.56 (0.677-0.632); p value = 0.398], and additive models [OR = 0.421 (0.262-0.675); p value = 0.0004]. Similarly, a significant association of rs895819 was determined by co-dominant [χ² = 9.669; p value ≤ 0.008], dominant (A/A vs. A/G + G/G) [OR = 0.285 (0.1242-0.6575); p value ≤ 0.0034], recessive (G/G vs. A/G + A/A) [OR = 0.900 (0.3202-3.519); p value = 1.000], and additive models [OR = 0.604 (0.3640-1.002); p value = 0.05] while no significant association of rs2168518 with CAD was found. Conclusion: The variants rs895819 and rs11614913 are the susceptibility factors for CAD.

Novel biomarkers of microRNAs in gastric cancer; an overview from diagnosis to treatment

The fourth frequent disease in the world and the second cause of cancer-related death is gastric cancer (GC). In this way, over 80% of diagnoses are made in the middle to advanced degrees of the disease, underscoring the requirement for innovative biomarkers that can be identified quickly. Meaningly, biomarkers that can complement endoscopic diagnosis and be used to detect patients with a high risk of GC are desperately needed. These biomarkers will allow for the accurate prediction of therapy response and prognosis in GC patients, as well as the development of an optimal treatment strategy for each individual. Conspicoiusly, microRNAs (miRNAs) and small noncoding RNA regulates the expression of target mRNA and thereby modifies critical biological mechanisms. According to the data, abnormally miRNAs expression in GC is linked to tumor growth, carcinogenesis, aggression and distant metastasis. Importantly, miRNA expression patterns and next-generation sequencing (NGS) can also be applied to analyze kinds of tissues and cancers. Given the high death rates and poor prognosis of GC, and the absence of a clinical diagnostic factor that is adequately sensitive to GC, research into novel sensitive and specific markers for GC diagnosis is critical. In this review,we evaluate the latest research findings that suggest the feasibility and clinical utility of miRNAs in GC.

Effect of miR-196a2 rs11614913 Polymorphism on Cancer Susceptibility: Evidence From an Updated Meta-Analysis

Background:MiR-196a2 rs11614913 polymorphism has been studied in a wide range of cancers throughout the years. Despite a large number of epidemiological studies performed in almost all ethnic populations, the contribution of this polymorphism to cancer risk is still inconclusive. Therefore, this updated meta-analysis was performed to estimate a meticulous correlation between miR-196a2 rs11614913 variant and cancer susceptibility. Methods: A systematic study search was carried out using PubMed, ScienceDirect, CNKI, EMBASE, Scopus, and Google Scholar databases following PRISMA guidelines to find necessary literature up to December 15, 2021. Pooled odds ratios with corresponding 95% confidence intervals were estimated using RevMan 5.4 based on ethnicities, cancer types, control sources, and genotyping methods. Results: A total of 152 studies, including 120 135 subjects (53 818 patients and 66 317 controls; 140 studies, after removing studies that deviated from HWE: 51 459 cases and 62 588 controls), were included in this meta-analysis. Quantitative synthesis suggests that the miR-196a2 rs11614913 genetic variant is significantly correlated with the reduced risk of overall cancer in CDM2, CDM3, RM, and AM (odds ratio < 1 and P < .05). It is also observed from ethnicity-based subgroup analysis that rs11614913 polymorphism is significantly (P < .05) linked with cancer in the Asian (in CDM2, CDM3, RM, AM) and the African population (in CDM1, CDM3, ODM). Stratified analysis based on the cancer types demonstrated a significantly decreased correlation for breast, hepatocellular, lung, and gynecological cancer and an increased association for oral and renal cell cancer. Again, the control population-based subgroup analysis reported a strongly reduced correlation for HB population in CDM2, RM, and AM. A substantially decreased risk was also observed for other genotyping methods in multiple genetic models. Conclusions:MiR-196a2 rs11614913 variant is significantly correlated with overall cancer susceptibility. Besides, rs11614913 is correlated with cancer in Asians and Africans. It is also correlated with breast, gynecological, hepatocellular, lung, oral, and renal cell cancer.

MicroRNA‑499a (rs3746444A/G) gene variant and susceptibility to type 2 diabetes‑associated end‑stage renal disease

Diabetic nephropathy (DN) is a major risk factor for end-stage renal disease (ESRD). MicroRNAs (miRNAs/miRs) and their variants may be implicated in health and disease, including DN. The present study aimed to investigate the association of the miRNA-499a gene (MIR499A) A/G seed region variant (rs3746444) with DN-associated ESRD susceptibility in patients with diabetes mellitus, and to determine whether there was an association between the different genotypes and the patients' laboratory and clinical data. A case-control pilot study was conducted on 180 adult patients with type 2 diabetes mellitus. A total of 90 patients with ESRD on regular hemodialysis were considered as the cases, and 90 age-, sex- and ethnicity-matched diabetic patients with normo-albuminuria were considered as the controls. MIR499A genotyping was performed using a TaqMan Real-Time allele discrimination assay. Results demonstrated that the MIR499A rs3746444*G variant conferred susceptibility to the development of ESRD under co-dominant [(odds ratio (95% confidence interval): 2.49 (1.41-3.89) and 2.41 (1.61-6.68) for heterozygous and homozygous comparison, respectively], dominant [2.30 (1.18-3.90)] and allelic [1.82 (1.17-2.83)] models. Different genotypes of the specified variant did not exhibit significant associations with the clinic-laboratory data of the studied patients or the circulating miR-499a plasma levels. In conclusion, results of the present study suggested that MIR499A rs3746444 may be a susceptibility variant for DN-associated ESRD in the study population. However, larger sample size studies with different ethnicities are warranted to verify these findings.

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.

Association between miR-27a rs895819 polymorphism and breast cancer susceptibility: Evidence based on 6118 cases and 7042 controls

BACKGROUND

Polymorphism in miR-27a rs895819 has been associated with breast cancer (BC) risk, but studies have reported inconsistent results. This meta-analysis investigated the possible association between miR-27a rs895819 polymorphism and BC risk.

METHODS

PubMed, EMBASE, Google Scholar, and the Chinese National Knowledge Infrastructure (CNKI) databases were systematically searched to identify relevant studies in English and Chinese. Meta-analyses were performed to examine the association between miR-27a rs895819 and BC susceptibility.

RESULTS

A total of 16 case-control studies involving 6118 cases and 7042 controls were included. Analysis using five genetic models suggested no significant association between miR-27a rs895819 polymorphism and BC risk in the total population, or specifically in Asian or Chinese subpopulations. In the Caucasian subpopulation, however, the G-allele and AG genotype at rs895819 were significantly associated with decreased BC risk according to the allelic model (OR 0.90, 95% CI 0.84-0.97, P = .004) and heterozygous model (OR 0.89, 95% CI 0.81-089, P = .02), while the wild-type AA genotype was significantly associated with increased BC risk according to the dominant model (OR 1.13, 95% CI 1.03-1.24, P = .007).

CONCLUSION

These results indicate that among Caucasians, the wild-type AA genotype at rs895819 may confer increased susceptibility to BC, while the G-allele and AG genotype may be protective factors. These conclusions should be verified in large, well-designed studies.

Associations of genetic variants of miRNA coding regions with pulmonary tuberculosis risk in China

Tuberculosis (TB) is the leading cause of death caused by single pathogenic microorganism, Mycobacterium tuberculosis (MTB). The study aims to explore the associations of microRNA (miRNA) single-nucleotide polymorphisms (SNPs) with pulmonary TB (PTB) risk. A population-based case−control study was conducted, and 168 newly diagnosed smear-positive PTB cases and 251 non-TB controls were recruited. SNPs located within miR-27a (rs895819), miR-423 (rs6505162), miR-196a-2 (rs11614913), miR-146a (rs2910164), miR-618 (rs2682818) were selected and MassARRAY^® MALDI-TOF System was employed for genotyping. SPSS19.0 was adopted for statistical analysis, non-conditional logistic regression was performed. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were computed to estimate the associations. Associations of haplotypes with PTB risk were performed with online tool. Rs895819 CT/CC genotype was associated with reduced PTB risk among female population (OR = 0.45, 95% CI: 0.23–0.98), P = 0.045. Haplotypes (combined with rs895819, rs2682818, rs2910164, rs6505162 and rs11614913) TCCCT, TAGCC, CCCCC, CCGCT and TCGAT were associated with reduced PTB risk and the ORs were 0.67 (95% CI: 0.45–0.99), 0.49 (0.25–0.94), 0.34 (95% CI: 0.14–0.81), 0.22 (95% CI: 0.06–0.84) and 0.24 (95% CI: 0.07–0.79), respectively; while the haplotypes of TAGCT, CCCCT, CACCT and TCCAT were associated with increased PTB risk, and the ORs were 3.63 (95% CI: 1.54–8.55), 2.20 (95% CI: 1.00–4.86), 3.90 (95% CI: 1.47–10.36) and 2.95 (95% CI: 1.09–7.99), respectively. Rs895819 CT/CC genotype was associated with reduced female PTB risk and haplotype TCCCT, TAGCC, CCCCC, CCGCT and TCGAT were associated with reduced PTB risk, while TAGCT, CCCCT, CACCT and TCCAT were associated with increased risk.

Association between miRNA-146a polymorphism and lung cancer susceptibility: A meta-analysis involving 6506 cases and 6576 controls

OBJECTIVE

We sought to analyze the association between miR-146a rs2910164 G > C polymorphism and susceptibility to lung cancer using a meta-analysis of case-control studies.

METHODS

We systematically searched for studies reporting on the relationship between miR-146a rs2910164 polymorphism and the risk of lung cancer in PubMed, Embase, Web of Science and Chinese National Knowledge Infrastructure databases. We then calculated pooled odds ratios (ORs), at 95% confidence interval (CI) to assess the aforementioned relationship. All the data were analyzed using statistical packages implemented in R version 3.6.2 (R Project for Statistical Computing), run in RStudio version 1.2.5033.

RESULTS

A total of fifteen studies, comprising 6506 cases and 6576 controls, were enrolled in this meta-analysis. Significant associations were observed between miR-146a rs2910164 polymorphism and the risk of lung cancer based on overall pooled subjects under the allele, heterozygous, homozygous, dominant, and recessive genetic models (C vs. G: OR = 1.27, 95% CI: 1.12-1.44; GC vs. GG: OR = 1.23, 95% CI: 1.03-1.46; CC vs. GG: OR = 1.51, 95% CI: 1.18-1.93; GC + CC vs. GG: OR = 1.33, 95% CI: 1.10-1.61; CC vs. GG + GC: OR = 1.32, 95% CI: 1.13-1.53). Ethnicity-based subgroup analyses revealed no statistically significant differences in Asians using heterozygous and dominant genetic models.

CONCLUSION

miR-146a rs2910164 G > C polymorphism may be a risk factor of lung cancer. Asian populations exhibiting heterozygous and dominant genotypes need to be further investigated to validate our findings.

microRNA-related single-nucleotide polymorphisms and breast cancer

Breast cancer, as the most common cancer in women which affects patients both mentally and physically, requires great attention in many areas and many levels as this cancer is known to be multifactorial. Single-stranded molecules called microRNAs with near 22 nucleotides are seen to act in central dogma of molecular biology by inhibiting the translation process; it is demonstrated that any alteration in their sequence especially single-nucleotide polymorphisms (SNPs) may lead into increasing the breast cancer risk. miR-SNPs are considered to be the potential biomarkers for early detection of breast cancer. As a result, this review documents the well-known miR-SNPs that are known to be associated with breast cancer. In this regard, two principals were discussed: (a) SNPs in the target genes of microRNAs and the alteration in gene expression due to this phenomenon; (b) changes based on the SNPs in the microRNA coding region and the impact on their interaction with target messenger RNA.

Associations of Single Nucleotide Polymorphism in miR-146a Gene with Susceptibility to Breast Cancer in the Iranian Female

BACKGROUND

MicroRNAs (miRNAs), short regulatory RNAs, function as negative regulators able to modulate gene expression. Just as other genetic variant, single nucleotide polymorphisms (SNPs) in miRNA genes, may have an impact on their expression and/or maturation and hence leading to different consequences in carcinogenesis. Accordingly, this study aimed to assess the frequency of miR-146a G/C (rs2910164) polymorphism and its association with susceptibility to breast cancer in Iranian women.

METHODS

We conducted a case-control study using Tetra ARMS polymerase chain reaction (Tetra ARMS PCR) method in 100 Iranian female participants (50 breast cancer patients and 50 controls). Besides, a number of sequenced samples were chosen to confirm the accuracy of genotyping by Tetra ARMA PCR. SPSS software was utilized for all statistical analyses. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were applied to analyze the association between the SNP frequency and breast cancer.

RESULTS

The frequency of genotypes for G/G, G/C, and C/C were 23 (46%), 26 (52%), and 1 (2%) among cases and 15 (30%), 33 (66%), and 2(4%) among controls, respectively. The results generated by the groups did not show any significant correlation between miR-146a G/C (rs2910164) polymorphism and breast cancer, either at genotype or allele levels (P>0.05). F-SNP-based in silico analysis indicated possible modifications in transcriptional regulations induced by miR-146a G/C (rs2910164) variations.

CONCLUSION

Overall, our results indicated no correlation between miR-146a G/C (rs2910164) polymorphism and genetic susceptibility to breast cancer in Iranian female populations. However, these findings need to be further confirmed by analyses of a larger number of cases.

Non-coding RNAs - A primer for the laboratory scientist

Advances in molecular genetics have identified several species of RNA that fail to translate - hence the non-coding RNAs. The two major groups within this class of nucleic acids are microRNAs (miRNA) and long non-coding RNAs (lncRNA). There is growing body of evidence supporting the view that these molecules have regulatory effect on both DNA and RNA. The objective of this brief review is to explain the molecular genetic of these molecules, to summarize their potential as mediators of disease, and to highlight their value as diagnostic markers and as tools in disease management.

Association of microRNA-27a rs895819 polymorphism with the risk of cancer: An updated meta-analysis

BACKGROUND

MiR-27a rs895819 polymorphism is considered as a tumor- related susceptibility gene. Previous meta-analyses evaluated the association the association between miR-27a rs895819 and cancer risk, but the results were inconsistent. The present meta-analysis was carried out to better estimate the correlation of rs895819 and cancer susceptibility.

METHODS

We searched several databases to identify relevant studies, including PubMed, EMBASE and the Cochrane Controlled Trials Register. The odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the association between miR-27a rs895819 and cancer risk.

RESULTS

The overall analysis showed the miR-27a rs895819 was not associated with cancer susceptibility in all models (dominant model: OR = 1.02, 95% CI:0.94-1.10, p = 0.632; recessive model: OR = 1.05, 95% CI: 0.92-1.76, p = 0.474; homozygote model: OR = 1.06, 95% CI: 0.91-1.23, p = 0.439; heterozygote model: OR = 1.00, 95% CI: 0.93-1.08, p = 0.934; and allele model: OR = 1.02, 95% CI: 0.96-1.09, p = 0.486). Interestingly, rs895819 A > G was significantly associated with colorectal cancer risk in recessive model (OR = 1.54, 95% CI: 1.29-1.83, p < 0.001), homozygote model (OR = 1.59, 95% CI: 1.31-1.92, p < 0.001), and allele model (OR = 1.22, 95% CI: 1.10-1.34, p < 0.001). In addition, rs895819 polymorphism was correlated with increased risk of breast cancer in the recessive model (OR = 0.81, 95% CI: 0.66-1.00, p = 0.046) and allele model (OR = 0.89, 95% CI: 0.80-0.98, p = 0.021).

CONCLUSIONS

Our results suggested that rs895819 polymorphism was correlated with increased risk of colorectal cancer and breast cancer, but not all types of cancer.

British Journal of Biomedical Science in 2019. What have we learned?

In 2019 the British Journal of Biomedical Science published 40 articles in the various disciplines that comprise biomedical science. These were one review, 22 original articles and 17 'In Brief' short reports. Of those citing original data, the majority were in cellular pathology (14 papers), clinical chemistry (9 papers), and microbiology (6 papers: 4 in bacteriology and 2 in virology). There were 3 papers in haematology and 2 in andrology, whilst 5 papers crossed traditional discipline boundaries (such as the molecular genetics of IL6, liver function tests, and hepatocellular carcinoma). Over two-thirds of papers used techniques in molecular genetics. The present report will summarise key aspects of these publications that are of greatest relevance to laboratory scientists.

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.

Genetic polymorphism of miRNA-196a and its target gene annexin-A1 expression based on ethnicity in Pakistani female breast cancer patients

Objective:

To evaluate the association of miR-196a rs11614913 C/T genetic variation and its target gene annexin A1 mRNA expression with breast cancer risk in Pakistani female ethnicities.

Methods:

This case control study, conducted from March 2017 to November 2018 included 295 breast cancer patients, 295 controls of three Pakistani ethnicities and archived 100 samples of cohort group for genotyping and expression profiling. Genotyping of miR-196a (rs11614913 C/T) was done by ARMS PCR technique. Annexin-A1 (ANXA1) mRNA expression was measured with qRT-PCR and detection of protein expression of ANXA1 was done by immunohistochemistry.

Results:

CC homozygous genotype of miR-196a rs11614913 was present in 81.4% of cases and 73.9% controls. C/T polymorphism was found to be significantly associated with decrease risk of breast cancer (OR=0.25 (0.11- 0.58, p <0.05). Similar trend was seen with the minor T allele (OR=0.55 (0.39-0.77, p <0.05, and both dominant and recessive models (OR=0.64; p=0.02 and OR=0.26, p=0.00). In the KPK ethnic group significant decrease association with breast cancer risk was observed (OR= 0.22 (0.09-0.53, p < 0.05). Immunohistochemical staining showed loss of ANXA1 protein expression in 72 samples, and significant association was observed with pathological type p=0. 00 and triple negative receptor status p=0.03 and with genotypes of miR-196ap=0.00. Increase relative expression of 2.81± .88 by qPCR analysis of ANXA1 mRNA was noted with TT genotype.

Conclusions:

Our results demonstrate that miR-196a rs11614913 C/T polymorphism is associated with a decreased risk and loss of protein expression in breast cancer in the Pakistani population.

Association of mir-196a-2 rs11614913 and mir-149 rs2292832 Polymorphisms With Risk of Cancer: An Updated Meta-Analysis

Background: Accumulating evidence suggests that functional dysregulations of miRNAs, especially miR-196a-2 and miR-149, in cancers could be attributed to polymorphisms in miRNA sequences. This study was aimed at clarifying the association of mir-196a-2 rs11614913 and mir-149 rs2292832 with cancer risk by performing an updated meta-analysis of genetic association studies. Methods: PubMed, Embase, Scopus, and ScienceDirect databases were searched until 9 April 2018 to identify eligible studies. Studies should meet the following criteria to be included in the meta-analysis: evaluation of genetic association between rs11614913 and/or rs2292832 and susceptibility to cancer; A case-control design; Written in English; Availability of sufficient data for estimating odds ratio (OR) and its 95% confidence interval (95%CI). Studies that met the following criteria were excluded: review articles, meta-analysis, abstracts or conference papers; duplicate publications; studies on animals or cell-lines; studies without a case-control design; studies that did not report genotype frequencies. Pooled ORs and 95% CIs were estimated using a total of 111 studies (41,673 cases and 49,570 controls) for mir-196a rs11614913 and 44 studies (15,954 cases and 19,594 controls) for mir-149 rs2292832. Stratified analysis according to quality scores, genotyping method, ethnicity, broad cancer category and cancer type was also performed. Results: Mir-196a-2 rs11614913 T allele was associated with decreased cancer risk in overall population. The association was only significant in Asians but not Caucasians. In subgroup analysis, significant associations were found in high quality studies, gynecological cancers, ovarian, breast, and hepatocellular cancer. Mir-149 rs2292832 was not associated with cancer risk in overall population and there were no differences between Asians and Caucasians. However, the T allele was associated with a decrease risk of gastrointestinal tract cancers under the heterozygote model and an increased risk of colorectal cancer under the recessive model. Conclusions: The present meta-analysis suggests that mir-196a-2 rs11614913 may contribute to the risk of cancer especially in Asians. Mir-149 rs2292832 may modulate the risk of gastrointestinal tract cancers especially colorectal cancer. This study had some limitations such as significant heterogeneity in most contrasts, limited number of studies enrolling Africans or Caucasians ancestry and lack of adjustment for covariates and environmental interactions.

British Journal of Biomedical Science in 2018: what have we learned?

In 2018 the British Journal of Biomedical Science published one guideline (in reproductive science) and 40 research articles in the various disciplines the comprise biomedical science. The latter were 24 original articles and 16 'In Brief' short reports. Of these, 23 are of note to only one of the sub-disciplines (seven each to biochemists and microbiologists, six to cell pathologists, and one each to cytologists, immunologists and reproductive scientists). Reflecting the increasing complexity of laboratory science, thirteen papers crossed one boundary (three papers each relevant to biochemists and immunologists, and to haematologists and biochemists), whilst four papers were relevant to three or more disciplines. Indeed, biochemical techniques were used in 18 papers, microbiological techniques in 9, whilst histopathology was relevant to 11 papers. Notably, 20 papers used techniques in chromosome analysis and molecular genetics. The present report will summarise key aspects of these publications that are of greatest relevance to laboratory scientists.

Influence of single nucleotide polymorphisms in pri-miR-124-1 and STAT3 genes on gastric cancer susceptibility

INTRODUCTION

MicroRNAs (miRNAs) are small ribonucleic acids that modulate the expression of downstream target genes. There is considerable evidence of their involvement in many malignancies, such as oesophageal and gastric. We hypothesised altered expressions of pri-miR-124-1 rs531564 and STAT3 rs1053023 polymorphisms in gastric cancer.

MATERIALS AND METHODS

Genomic DNA was extracted from peripheral blood of 250 patients with gastric cancer and 310 healthy individuals. The RFLP method was applied for determination of pri-miR-124 polymorphism and the AS-PCR method for STAT3 polymorphism.

RESULTS

The distribution of rs531564 genotypes in cases and controls was different: the G allele carriers had a reduced gastric cancer risk (OR = 0.62; 95%CI = 0.49-0.80, P = 0.0002). Presence of the minor allele of STAT3 (rs1053023) was linked with higher risk of gastric cancer (OR = 2.29; 95% CI = 1.79-2.93, P < 0.0001). Compared with the most frequent haplotype C-G [the SNP order was pri-miR-124-1 (rs531564) and STAT3 (rs1053023)] in controls, C-A haplotype was associated with a significantly increased risk of gastric cancer (OR = 2.28; 95%CI = 1.64-3.09, P < 0.0001).

CONCLUSION

There is a strong link between pri-miR-124-1 rs531564 and STAT3 rs1053023 and gastric cancer that may be pathogenic, and so worthy of further investigation.