Pri-miR-34b/c rs4938723 polymorphism is associated with a decreased risk of gastric cancer

The microRNA Let-7 and its exosomal form: Epigenetic regulators of gynecological cancers

Many types of gynecological cancer (GC) are often silent until they reach an advanced stage, and are therefore often diagnosed too late for effective treatment. Hence, there is a real need for more efficient diagnosis and treatment for patients with GC. During recent years, researchers have increasingly studied the impact of microRNAs cancer development, leading to a number of applications in detection and treatment. MicroRNAs are a particular group of tiny RNA molecules that regulate regular gene expression by affecting the translation process. The downregulation of numerous miRNAs has been observed in human malignancies. Let-7 is an example of a miRNA that controls cellular processes as well as signaling cascades to affect post-transcriptional gene expression. Recent research supports the hypothesis that enhancing let-7 expression in those cancers where it is downregulated may be a potential treatment option. Exosomes are tiny vesicles that move through body fluids and can include components like miRNAs (including let-7) that are important for communication between cells. Studies proved that exosomes are able to enhance tumor growth, angiogenesis, chemoresistance, metastasis, and immune evasion, thus suggesting their importance in GC management.

Non-Coding RNA as Biomarkers and Their Role in the Pathogenesis of Gastric Cancer-A Narrative Review

Non-coding RNAs (ncRNAs) represent a broad family of molecules that regulate gene expression, including microRNAs, long non-coding RNAs and circular RNAs, amongst others. Dysregulated expression of ncRNAs alters gene expression, which is implicated in the pathogenesis of several malignancies and inflammatory diseases. Gastric cancer is the fifth most frequently diagnosed cancer and the fourth most common cause of cancer-related death. Studies have found that altered expression of ncRNAs may contribute to tumourigenesis through regulating proliferation, apoptosis, drug resistance and metastasis. This review describes the potential use of ncRNAs as diagnostic and prognostic biomarkers. Moreover, we discuss the involvement of ncRNAs in the pathogenesis of gastric cancer, including their interactions with the members of major signalling pathways.

MicroRNA-34 and gastrointestinal cancers: a player with big functions

It is commonly assumed that gastrointestinal cancer is the most common form of cancer across the globe and is the leading contributor to cancer-related death. The intricate mechanisms underlying the growth of GI cancers have been identified. It is worth mentioning that both non-coding RNAs (ncRNAs) and certain types of RNA, such as circular RNAs (circRNAs), long non-coding RNAs (lncRNAs), and microRNAs (miRNAs), can have considerable impact on the development of gastrointestinal (GI) cancers. As a tumour suppressor, in the group of short non-coding regulatory RNAs is miR-34a. miR-34a silences multiple proto-oncogenes at the post-transcriptional stage by targeting them, which inhibits all physiologically relevant cell proliferation pathways. However, it has been discovered that deregulation of miR-34a plays important roles in the growth of tumors and the development of cancer, including invasion, metastasis, and the tumor-associated epithelial-mesenchymal transition (EMT). Further understanding of miR-34a's molecular pathways in cancer is also necessary for the development of precise diagnoses and effective treatments. We outlined the most recent research on miR-34a functions in GI cancers in this review. Additionally, we emphasize the significance of exosomal miR-34 in gastrointestinal cancers.

Novel Biomarkers of Gastric Adenocarcinoma: Current Research and Future Perspectives

Simple Summary

Gastric cancer is characterized by poor survival rates despite surgery and chemotherapy. Current research focuses on biomarkers to improve diagnosis and prognosis, and to enable targeted treatment strategies. The aim of our review was to give an overview over the wide range of novel biomarkers in gastric cancer. These biomarkers are targets of a specific treatment, such as antibodies against human epidermal growth factor receptor 2. Other promising biomarkers for targeted therapies that have shown relevance in clinical trials are vascular endothelial growth factor, programmed cell death protein 1, and Claudin 18.2. There is a vast number of biomarkers based on DNA, RNA, and protein expression, as well as detection of circulating tumor cells and the immune tumor microenvironment.

Abstract

Overall survival of gastric cancer remains low, as patients are often diagnosed with advanced stage disease. In this review, we give an overview of current research on biomarkers in gastric cancer and their implementation in treatment strategies. The HER2-targeting trastuzumab is the first molecular targeted agent approved for gastric cancer treatment. Other promising biomarkers for targeted therapies that have shown relevance in clinical trials are VEGF and Claudin 18.2. Expression of MET has been shown to be a negative prognostic factor in gastric cancer. Targeting the PD-1/PD-L1 pathway with immune checkpoint inhibitors has proven efficacy in advanced gastric cancer. Recent technology advances allow the detection of circulating tumor cells that may be used as diagnostic and prognostic indicators and for therapy monitoring in gastric cancer patients. Prognostic molecular subtypes of gastric cancer have been identified using genomic data. In addition, transcriptome profiling has allowed a comprehensive characterization of the immune and stromal microenvironment in gastric cancer and development of novel risk scores. These prognostic and predictive markers highlight the rapidly evolving field of research in gastric cancer, promising improved treatment stratification and identification of molecular targets for individualized treatment in gastric cancer.

MiR-139-5p inhibits the proliferation of gastric cancer cells by targeting Regulation of Nuclear Pre-mRNA Domain Containing 1B

Regulation of Nuclear Pre-mRNA Domain Containing 1B (RPRD1B) has been of great interest in the field of oncology in recent years. The relationship between miRNAs and RPRD1B in gastric cancer (GC) has not been adequately reported. This study was designed to screen RPRD1B-targeted miRNAs and investigate its regulatory mechanism in GC cells. Quantitative RT-PCR and in situ hybridization were used to detect miRNA expression in GC tissues. Colony formation, EdU cell proliferation assay, and flow cytometry were used to analyze the cell cycle. Database-assisted gene expression analysis revealed that RPRD1B was targeted and regulated by miRNA-139-5p in GC. miRNA-139-5p expression was higher in GC tissue than in normal tissues and significantly correlated with tumor size, pathological stage, and disease-free survival of GC (p < 0.05). MiRNA-139-5p regulates GC cell proliferation and affects the transition from G1 to S phase. It binds explicitly to the 2013-2019 sites of the 3'UTR of RPRD1B and negatively regulates RPRD1B expression. We demonstrated that the ability of miR-139-5p to regulate GC cell proliferation depends on RPRD1B. This process is accompanied by changes in Cyclin D1 protein expression. We established a miR-139-5p/RPRD1B/tumor proliferation axis in GC, which may serve as novel biomarkers and drug targets for GC.

Association of miR-34b/c rs4938723 and TP53 Arg72Pro Polymorphisms with Neuroblastoma Susceptibility: Evidence from Seven Centers

Neuroblastoma is a pediatric malignancy arising from the developing peripheral nervous system. p53 and downstream effector miR-34b/c have critical tumor suppressing functions. TP53 Arg72Pro (rs1042522 C > G) and miR-34b/c rs4938723 (T > C) polymorphisms have been known to modify cancer susceptibility. This study was performed to validate the association of these two polymorphisms and neuroblastoma risk with 819 cases and 1780 controls. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used to assess the strength of the associations. False positive report possibility analysis was adopted to dissect out real significant associations from chance findings. We found that both TP53 Arg72Pro (CG/GG vs. CC: adjusted OR = 0.82, 95% CI = 0.69-0.98) and miR-34b/c rs4938723 (TC/CC vs. TT: adjusted OR = 0.64, 95% CI = 0.54-0.75) were associated with decreased neuroblastoma susceptibility. Stratify analyses further confirmed the protective effect among some subgroups. Moreover, subjects with variant alleles of both polymorphisms were associated with more significantly decreased neuroblastoma risk (CG/TC vs. CC/TT: adjusted OR = 0.38, 95% CI = 0.28-0.50; GG/TC vs. CC/TT: adjusted OR = 0.43, 95% CI = 0.30-0.63) than those carrying variant allele of either one polymorphism (CC/TC vs. CC/TT: adjusted OR = 0.51, 95% CI = 0.37-0.69; CG/TT vs. CC/TT: adjusted OR = 0.71, 95% CI = 0.55-0.92), suggesting cumulative effects of the polymorphisms. False positive report possibility analysis further verified that our findings are noteworthy. Overall, we confirmed that miR-34b/c rs4938723 and TP53 Arg72Pro conferred decreased neuroblastoma risk and two polymorphisms exerted stronger protective effects against neuroblastoma than either one alone.

A genetic variant rs13293512 in the promoter of let-7 is associated with an increased risk of breast cancer in Chinese women

Growing evidence has demonstrated that single-nucleotide polymorphisms (SNPs) in the promoter of miRNA may influence individuals’ susceptibility to human diseases. We examined two SNPs rs10877887 and rs13293512 in the promoters of let-7 family to determine if the two SNPs were related to the occurrence of breast cancer (BC). Genotyping of the two SNPs was performed by PCR and restriction fragment length polymorphism analysis or TaqMan assay in 301 BC patients and 310 age matched controls. We found a higher frequency of rs13293512 CC genotype and rs13293512 C allele amongst BC patients (CC vs TT: adjusted odds ratio (OR) = 1.78; 95% CI: 1.14–2.80; P=0.012; C vs T: adjusted OR = 1.33; 95% CI: 1.06–1.67; P=0.013). Stratification analysis showed that rs13293512 CC genotype was associated with an increased risk of BC in patients with negative estrogen receptor (adjusted OR = 2.39; 95% CI: 1.32–4.30; P=0.004), patients with negative progesterone receptor (adjusted OR = 1.92; 95% CI: 1.11–3.33; P=0.02), patients with T1-2 stage cancer (adjusted OR = 1.77; 95% CI: 1.07–2.93; P=0.03), and patients with N1-3 stage cancer (adjusted OR = 1.89; 95% CI: 1.13–3.17; P=0.015). These findings suggest that rs13293512 in the promoter of let-7a-1/let-7f-1/let-7d cluster may be a possible biomarker for the development of BC in Chinese women.

Rs4938723 Polymorphism Is Associated with Susceptibility to Hepatocellular Carcinoma Risk and Is a Protective Factor in Leukemia, Colorectal, and Esophageal Cancer

BACKGROUND Growing evidence indicates that a non-coding RNA named miR-34b/c plays crucial roles in carcinogenesis, and its common polymorphism, pri-miR-34b/c rs4938723, also participates in this process and is associated with cancer susceptibility. However, this association was previously undefined and ambiguous. Therefore, we carried out an updated analysis to evaluate this relationship between rs4938723 polymorphism and cancer susceptibility. MATERIAL AND METHODS PubMed, EMbase, Web of Science and Chinese language (WanFang, CNKI and VIP) databases were searched for relevant studies until Sep 10, 2018. Odds ratios and 95% confidence interval were applied to assess this relationship. RESULTS Thirty case-control studies were retrieved. No positive association was found in either the overall study population or in the subgroups, based on ethnicity, source of group, sex, smoking, and drinking status. The main results were observed in the stratified analysis subgroups in cancer type subgroup: rs4938723 polymorphism may be a protective factor in leukemia, colorectal cancer, and esophageal cancer; however, C-allele was a risk factor in carriers for hepatocellular carcinoma. Last but not the least, poor positive results were discovered in the age subgroup. CONCLUSIONS Current meta-analysis suggested that rs4938723 polymorphism was potentially associated with hepatocellular carcinoma risk, but this polymorphism had a decreased association for susceptibility to esophageal cancer, leukemia, and colorectal cancer. Furthermore, studies with larger sample sizes and including gene-gene or gene-environment interactions should be carried out to elucidate the role of rs4938723 polymorphism in cancer risk.

Association Between Genetic Variant in the Promoter of Pri-miR-34b/c and Risk of Glioma

Growing evidence indicates that p53 can regulate the expression of miRNAs, particularly the miR-34 family members, which are described as potential tumor suppressors. Loss of miR-34 suppresses TP53-mediated cell death, whereas over expression of miR-34 induced apoptosis. The study designed to investigate the association between the pir-miR-34b/c rs4938723, TP53 Arg72Pro and the risk of glioma. We genotyped the two polymorphisms in175 glioma patients and 235 healthy controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing assay. Association analysis showed that the CC genotype of the pir-miR-34b/c rs4938723 was associated with a significantly decreased risk of glioma compared to the TT genotype (CC vs. TT: adjusted OR = 0.43;95% CI, 0.21–0.87,P = 0.02). Moreover, a significant association between the patients with glioma and controls was also observed in a recessive model (OR = 0.41; 95% CI, 0.21–0.81, P = 0.007). In contrast, the CC genotype of the TP53 Arg72Pro was associated with a significantly increased risk of glioma compared to the GG genotype (CC vs. GG: adjusted OR = 1.73;95% CI, 1.04–2.89,P = 0.04), and a significant association between the patients with glioma and controls was also observed in a recessive model (OR = 2.00; 95% CI, 1.26–3.18, P = 0.003). These findings suggest that the pri-miR-34b/c rs4938723CC and TP53 Arg72-Pro polymorphisms may be associated with the risk of glioma.

Association between miR-34b/c rs4938723 polymorphism and risk of cancer: An updated meta-analysis of 27 case-control studies

Several studies investigated the association between miR-34b/c rs4938723 polymorphism and the risk of several human cancers, but the findings remain inconclusive. To evaluate the impact of miR-34b/c rs4938723 on cancer risk, we performed a meta-analysis on all available studies including 12 361 cancer cases and 14 270 controls. Eligible studies were identified by searching PubMed, Web of Science, Scopus, and Google scholar databases. Pooled odds ratios with 95% confidence intervals were calculated in codominant, dominant, recessive, overdominant, and allele models to quantitatively estimate the association. The overall findings showed no significant association between miR-34b/c rs4938723 polymorphism and cancer risk in codominant, dominant, recessive, overdominant, and allele inheritance model. However, in stratified analysis by cancer types, the rs4938723 polymorphism significantly increased the risk of gastrointestinal cancer, hepatocellular carcinoma. In addition, the rs4938723 polymorphism was associated with decreased risk of esophageal squamous cell carcinoma, colorectal cancer, and acute lymphoblastic leukemia. The findings did not support an association between rs4938723 variant and digestive tract as well as gastric cancer. In summary, the findings of this meta-analysis indicated that the miR-34b/c rs4938723 polymorphism might be associated with some cancer development. Larger and well-designed studies are necessary to estimate this association in detail.

Association between Pri-miR-34b/c rs4938723 polymorphism and bladder cancer risk

Several studies examined the impact of miR-34b/c rs4938723 polymorphism and cancer risk, but the findings are inconsistent. However, no study has been conducted to inspect the impact of miR-34b/c polymorphism on bladder cancer. This study aimed to assess possible association between rs4938723 polymorphism and bladder cancer risk. This case-control study was done on 136 pathologically proven bladder cancer patients and 144 controls. Genotyping of Pri-miR-34b/c rs4938723 polymorphism was achieved by using the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. Our findings did not show any statistically significant differences in genotype and allele frequencies between bladder cancer and controls. Larger sample sizes with diverse ethnicities are required to validate our findings.

Association of Common Genetic Variants in Pre-microRNAs and Neuroblastoma Susceptibility: A Two-Center Study in Chinese Children

Neuroblastoma is a commonly occurring extracranial pediatric solid tumor without defined etiology. Polymorphisms in pre-miRNAs have been demonstrated to associate with the risk of several cancers. So far, no such polymorphism has been investigated in neuroblastoma. With this in mind, we performed a two-center case-control study to assess the association of genetic variants in pre-miRNAs and neuroblastoma susceptibility in Chinese children, including 393 cases and 812 controls. We found that miR-34b/c rs4938723 T > C polymorphism was significantly associated with decreased neuroblastoma risk (TC versus TT: adjusted odds ratio [OR] = 0.51, 95% confidence interval [CI] = 0.39-0.67; TC/CC versus TT: adjusted OR = 0.62, 95% CI = 0.48-0.79). We also observed the significant association between the miR-218 rs11134527 A > G polymorphism and decreased neuroblastoma risk (AG versus AA: adjusted OR = 0.73, 95% CI = 0.56-0.96). Stratified analysis further demonstrated that the protective effect of the rs4938723 T > C polymorphism remained prominent in the subgroups, regardless of age, gender, and clinical stages. In term of sites of origin, this polymorphism significantly reduced the risk of tumors originating from the adrenal gland. We further validated the significant results using false-positive report probability analyses. Overall, the miR-34b/c rs4938723 T > C and miR-218 rs11134527 A > G polymorphisms displayed a protective role from neuroblastoma. These findings need further validation.

A polymorphism rs4705341 in the flanking region of miR-143/145 predicts risk and prognosis of colorectal cancer

The aim of this study was to investigate the effect of a polymorphism rs4705341 in the flanking region of miR-143/145 on the risk of colorectal cancer (CRC). The rs4705341 polymorphism was analyzed in 1002 cases and 1062 controls using a polymerase chain reaction-restriction fragment length polymorphism method. We found a significantly reduced CRC susceptibility with miR-143/145 rs4705341 in homozygote comparison (adjusted OR = 0.66, 95%CI, 0.50-0.88, P = 0.004), dominant genetic model (adjusted OR = 0.80, 95%CI, 0.67-0.96, P = 0.015), recessive genetic model (adjusted OR = 0.73, 95%CI, 0.56-0.94, P = 0.016), and allele comparison (adjusted OR = 0.83, 95%CI, 0.73-0.94, P = 0.004). Stratification analysis showed that the rs4705341 was related to differentiated status, clinical stage I-II, and patients without lymph node metastasis. Moreover, patients with rs4705341GG had a longer overall survival (adjusted HR = 5.57, 95%CI, 0.95-32.68). These findings indicate that the miR-143/145 rs4705341 may be used as a potential biomarker for the development and prognosis of CRC.

An updated meta-analysis of 23 case-control studies on the association between miR-34b/c polymorphism and cancer risk

The association between in microRNA-34b/c gene rs4938723 polymorphisms and cancer risk remains inconclusive. This meta-analysis was performed to analyze the association between microRNA-34b/c rs4938723 polymorphism and risk for cancer development. In total, 304 studies from PubMed, Embase, Web of Science, Wanfang, and Chinese National Knowledge Infrastructure databases were examined, and 23 studies were included in this meta-analysis. The 23 selected studies involved 10,812 cancer cases and 11,719 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to measure the strength of the association. Our results indicate a significant association between the rs4938723 polymorphism and cancer risk in the overdominant model (P heterogeneity = 0.018, OR = 1.093, and 95% CI = 1.015-1.177 for CT vs. CC/TT). Using a stratified subgroup analysis, rs4938723 polymorphisms were associated with an increased risk for hepatocellular carcinoma, but decreased risk for colorectal, gastric, and esophageal squamous cell cancer. These findings indicate that the rs4938723 gene is a susceptible locus for cancer.

SNP-SNP interactions of three new pri-miRNAs with the target gene PGC and multidimensional analysis of H. pylori in the gastric cancer/atrophic gastritis risk in a Chinese population

Gastric cancer (GC) is a multistep complex disease involving multiple genes, and gene–gene interactions have a greater effect than a single gene in determining cancer susceptibility. This study aimed to explore the interaction of the let-7e rs8111742, miR-365b rs121224, and miR-4795 rs1002765 single nucleotide polymorphisms (SNPs) with SNPs of the predicted target gene PGC and Helicobacter pylori status in GC and atrophic gastritis (AG) risk. Three miRNA SNPs and seven PGC SNPs were detected in 2448 cases using the Sequenom MassArray platform. Two pairwise combinations of miRNA and PGC SNPs were associated with increased AG risk (let-7e rs8111742 – PGC rs6458238 and miR-4795 rs1002765 – PGC rs9471643). Singly, miR-365b rs121224 and PGC rs6912200 had no effect individually but in combination they demonstrated an epistatic interaction associated with AG risk. Similarly, let-7e rs8111742 and miR-4795 rs1002765 SNPs interacted with H. pylori infection to increase GC risk (rs8111742: P_interaction = 0.024; rs1002765: P_interaction = 0.031, respectively). A three-dimensional interaction analysis found miR-4795 rs1002765, PGC rs9471643, and H. pylori infection positively interacted to increase AG risk (P_{interaction =} 0.027). Also, let-7e rs8111742, PGC rs6458238, and H. pylori infection positively interacted to increase GC risk (P_{interaction =} 0.036). Furthermore, both of these three-dimensional interactions had a dosage–effect correspondence (P_trend < 0.001) and were verified by MDR. In conclusion, the miRNAs SNPs (let-7e rs8111742 and miR-4795 rs1002765) might have more superior efficiency when combined with PGC SNPs and/or H. pylori for GC or AG risk than a single SNP on its own.

Association between genetic polymorphisms in the promoters of let-7 and risk of cervical squamous cell carcinoma

Numerous reports showed low levels of let-7 family in cervical cancer, acting as tumor suppressors by regulating multiple target genes. Genetic variants in the promoter of miRNA have been reported to influence individuals' susceptibility to human diseases. We aimed to investigate the association of rs10877887 and rs13293512 polymorphisms in the promoters of let-7 with risk of cervical squamous cell carcinoma (CSCC). A total of 331 patients with CSCC and 358 controls were included. Genotyping of rs10877887 was done using polymerase chain reaction-restriction fragment length polymorphism analysis. Genotyping of rs13293512 was performed using Taqman allelic discrimination. Relative expression of let-7 family was determined using quantitative real-time polymerase chain reaction. The rs10877887CC genotype was significantly associated with an increased risk of CSCC compared with the rs10877887TT (adjusted OR=2.11, 95% CI, 1.31-3.40, p-value=0.002) or rs10877887 TT/CT genotypes (adjusted OR=2.11, 95% CI, 1.34-3.31, p-value<0.001). Similarly increased risk of CSCC was observed when compared rs10877887T with rs10877887C allele (adjusted OR=1.35, 95% CI, 1.08-1.69, p-value=0.008). Combined analysis showed that individuals carrying the genotypes of rs10877887CC+rs13293512CC had a 4.78-fold higher risk to develop CSCC compared with those carrying the genotypes of rs10877887CT/TT+rs13293512CT/TT (OR=4.78, 95% CI, 1.78-12.84, p-value=0.001). Additionally, patients harboring rs10877887CC genotype had a lower level of let-7i in CSCC tissues (p-value=0.02). This observation indicates that rs10877887 may be a useful biomarker for the etiology of CSCC.

Pri-miR-34b/c rs4938723 polymorphism is associated with the risk of childhood acute lymphoblastic leukemia

MicroRNAs (miRNAs), small noncoding regulatory RNAs, are key regulators of gene expression. The impact of Pri-miR-34b/c rs4938723 variant on development of various cancers is still controversial. In the present study, we examined whether a rs4938723 variant located at the promoter region of Pri-miR-34b/c is associated with childhood ALL. A total of 110 children with acute lymphoblastic leukemia (ALL) and 120 healthy children were recruited to participate in this study. The rs4938723 variant was genotyped by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. The rs4938723 variant decreased the risk of ALL in heterozygous (TC vs OR = 0.48, 95% CI = 0.28-0.84, p = 0.012, TC vs TT) and overdominant (OR = 0.51, 95% CI = 0.30-0.89, p = 0.0.020, TC vs TT + CC): OR = 1.32, 95% CI = 0.67-2.59, p = 0.498; C vs T: OR = 0.99, 95% CI = 0.75-1.31, p = 0.986) inheritance models tested. The C allele significantly decreased the risk of childhood ALL compared to T allele (OR = 0.52, 95% CI = 0.33-0.83, p = 0.006). Our findings proposed an association between Pri-miR-34 b/c rs4938723 variant and risk of childhood ALL development in a sample of Iranian population.

A functional variant rs353292 in the flanking region of miR-143/145 contributes to the risk of colorectal cancer

MicroRNA (miR)-143 and miR-145 have been identified as molecular regulators in cell proliferation, cell growth, clone formation, apoptosis, cell cycle, invasion, and migration. We previously found that rs353292 in the flanking region of miR-143/145 showed a high frequency in patients with colorectal cancer (CRC). To identify whether the rs353292 polymorphism is a risk factor for CRC, we conducted this study with larger samples. A total of 809 patients with CRC and 1005 gender matched controls were collected. The rs353292 polymorphism was genotyped by using TaqMan allelic discrimination. Dual luciferase reporter assay was carried out to measure the transcriptional activity. We found that the rs353292 polymorphism was associated with an increased risk for developing CRC in heterozygous comparison (adjusted OR = 1.70, 95% CI, 1.32–2.20, P < 0.001), dominant genetic model (adjusted OR = 1.62, 95% CI, 1.26–2.09, P < 0.001), and allele comparison (adjusted OR = 1.46, 95% CI, 1.16–1.84, P = 0.001). The rs353292 CT/TT carriers exhibited a lower expression of miR-143 compared to the CC carriers (P = 0.04). Moreover, the pGL3-rs353292T displayed a significantly lower luciferase activity than pGL3-rs353292C (P < 0.01). These findings indicate that the rs353292 polymorphism is functional and may be a risk factor for the development of CRC.

Evaluation of the pri-miR-34b/c rs4938723 polymorphism and its association with breast cancer risk

MicroRNAs (miRNAs or miRs) are a family of small non-coding RNAs that function as oncogenes or tumor suppressor genes. Recent evidence suggests that the pri-miR-34b/c rs4938723 variant is associated with the development of cancer. At present, there is an inconsistent association between the single-nucleotide polymorphism in pri-miR-34b/c and cancer in the limited studies. The present study is a case-control investigation, with 263 breast cancer (BC) patients and 221 control women, which examined the potential association of the pri-miR-34b/c rs4938723 polymorphisms with BC susceptibility. The polymorphisms were genotyped by the polymerase chain reaction restriction fragment length polymorphism method. No significant association between the pri-miR-34b/c rs4938723 variant and BC was identified [TC vs. TT: Odds ratio (OR), 0.87; 95% confidence interval (CI), 0.60-1.26; P=0.506; CC vs. TT: OR, 1.22; 95% CI, 0.61-2.47; P=0.600; TC+CC vs. TT: OR, 0.91; 95% CI, 0.64-1.31; P=0.648; CC vs. TT+TC: OR, 1.32; 95% CI, 0.67-2.59; P=0.498; C vs. T: OR, 0.99; 95% CI, 0.75-1.31; P=0.986]. However, a significant association was observed between the pri-miR-34b/c rs4938723 genotypes and clinicopathological characteristics, such a grade, progesterone receptor and human epidermal growth factor receptor 2 status were observed (P<0.05). These findings suggest that the pri-miR-34b/c rs4938723 variant may not be a risk factor for the development of BC.

Is miR-34a a Well-equipped Swordsman to Conquer Temple of Molecular Oncology?

Overwhelmingly increasing advancements in miRNA biology have opened new avenues for pharmaceutical companies to initiate studies on designing effective, safe, and therapeutically active candidates using miRNA mimetics and miRNA inhibitors. In accordance with this approach, development of miravirsen and SPC3649, an LNA-based (locked nucleic acid) antisense molecule against miR-122, to treat hepatitis C has sparked interest in identifying most efficient microRNAs for journey from bench-top toward pharmaceutical industry and breakthroughs in delivery technology will pave the way to 'final frontier'. MRX34, a liposome-formulated mimic of miR-34 for treatment of metastatic cancer with liver involvement and unresectable primary liver cancer, has also entered in clinical trial. There is a successive increase in the research work related to miR-34 biology and miRNA regulation of modulators of intracellular signaling cascades. We partition this review into how miR-34a is regulated by different proteins and how Wnt- and TGF-induced intracellular signaling cascades are modulated by miR-34a. In this review, we bring to limelight how miR-34a regulates its target genes to induce apoptosis and inhibit cell proliferation as evidenced by in vitro and in vivo analysis. We also discuss miR-34 regulation of PDGFR and c-MET and recent advancements in nanotechnologically delivered miR-34a. Spotlight is also set on modulation of chemotherapeutic sensitivity by miR-34a in cancer cells using reconstruction studies. Clinical trial of miR-34 is indicative of its tremendous potential, and continuous cutting research will prove to be effective in efficiently translating laboratory findings into clinically effective therapeutics.

Combined analysis of pri-miR-34b/c rs4938723 and TP53 Arg72Pro with cervical cancer risk

miR-34 family members can form a p53-miR-34 positive feedback loop and induce apoptosis, DNA repair, angiogenesis, and cell cycle arrest. We conducted a case-control study to examine whether two polymorphisms (i.e., rs4938723 in the promoter of pri-miR-34b/c and TP53 Arg72Pro) were linked to the carcinogenesis of cervical cancer among Chinese Han women. Genotypes of the two polymorphisms in 328 cervical cancer patients and 568 control subjects were determined by using a polymerase chain reaction-restriction fragment length polymorphism assay. We found a significantly increased cervical cancer risk in the pri-miR-34b/c rs4938723 under dominant and overdominant model (CT/CC vs. TT: adjusted OR = 1.34, 95 % CI = 1.01-1.77; CT vs. TT/CC: adjusted OR = 1.37, 95 % CI = 1.05-1.80, respectively). Increased cervical cancer risks were also found in the TP53 Arg72Pro under a heterozygous comparison and overdominant model (CG vs. GG: adjusted OR = 1.44, 95 % CI = 1.06-1.95; CG vs. GG/CC: adjusted OR = 1.47, 95 % CI = 1.12-1.94, respectively). Stratification analysis showed that patients carrying the pri-miR-34b/c rs4938723 CT genotype had a significantly increased risk for developing poorly differential status and clinical stage I. Moreover, increased cancer risks were observed for the TP53 Arg72Pro polymorphism in patients with poorly differential status, clinical stage II, and without lymph node metastasis. Combined analysis revealed that the genotypes of rs4938723 CT/CC and TP53 Arg72Pro CG/CC had an increased cervical cancer risk (OR = 2.21, 95 % CI = 1.38-3.53). These findings suggest that the pri-miR-34b/c rs4938723 and TP53 Arg72Pro polymorphisms may contribute to the genesis of cervical cancer.

Pri-Mir-34b/C and Tp-53 Polymorphisms are Associated With The Susceptibility of Papillary Thyroid Carcinoma: A Case-Control Study

Tumor suppressor p53 directly regulated the abundance of the miR-34b/c. The interaction might contribute to certain cancer. We hypothesized that rs4938723 in the promoter region of pri-miR-34b/c and TP-53 Arg72Pro may be related to the risk of papillary thyroid carcinoma (PTC). A total of 784 patients with PTC and 1006 healthy controls were recruited to participate in this study. The variants were discriminated using a polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP). Additionally, the relative expression levels of miR-34b/c and TP-53 in 44 paired samples were revealed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). A significantly increased risk of PTC was observed in the miR-34b/c rs4938723 CT, CC, and CT/CC genotypes compared with the TT genotype (CT vs TT: adjusted odds ratio [OR] = 1.51, 95%confidence interval [CI] = 1.23-1.85; CC vs TT: adjusted OR = 1.89, 95%CI = 1.39-2.63; CT/CC vs TT: adjusted OR = 1.59, 95%CI = 1.30-1.92, respectively). Significantly increased PTC susceptibility was also associated with the TP-53 Arg72Pro CC and CG/CC genotypes compared with the GG genotype (CC vs GG: adjusted OR = 2.04, 95%CI = 1.54-2.70; CG/CC vs GG: adjusted OR = 1.35, 95%CI = 1.11-1.67, respectively). Stratification analysis revealed that patients carrying the TP-53 Arg72Pro C allele and CC genotype had a significantly increased risk for developing N1 (C vs. G: OR = 1.27, 95%CI = 1.03-1.56; CC vs. GG: OR = 1.62, 95%CI = 1.07-2.46, respectively). Combined analysis showed that the genotypes of rs4938723 CT/CC + TP-53CG/CC increased the risk of PTC compared with rs4938723TT + TP-53GG (OR = 2.25, 95%CI = 1.67-3.03). Additionally, level of miR-34b was significantly upregulated in PTC patients.These findings indicate that the miR-34b/c rs4938723 and TP-53 Arg72Pro polymorphisms may contribute to the susceptibility of PTC.