Wild-type genotypes of BRCA1 gene SNPs combined with micro-RNA over-expression in mammary tissue leading to familial breast cancer with an increased risk of distant metastases’ occurrence

Global trends in BRCA-related breast cancer research from 2013 to 2022: A scientometric analysis

Introduction

Since the mid-2000s, breast cancer incidence among women has slowly increased at about 0.5% per year. In the last three decades, Breast Cancer Susceptibility Gene (BRCA) has been proven to be the crucial gene in encouraging the incidence and development of breast cancer. However, scientometric analysis on BRCA-related breast cancer is in shortage. Thus, to have a clear understanding of the current status and catch up with the hotspots, a scientometric analysis was conducted on specific academic publications collected from the Web of Science (WoS).

Methods

We searched the Web of Science Core Collection (WoSCC) to procure associated articles as our dataset. Bibliometric, CiteSpace, VOSviewer, and HistCite software were then applied to conduct visual analyses of countries, institutions, journals, authors, landmark articles, and keywords in this research field.

Results

A total of 7,266 articles and 1,310 review articles published between 2013 to 2022 were retrieved eventually. The annual output steadily rose year by year and peaked in 2021. The USA led the way in the number of published works, total citations, and collaboration. Breast Cancer Research and Treatment was the most favoured journal in this research field. Narod SA from the University of Toronto produced the most publications. At last, the most prominent keywords were "breast cancer" (n=1,778), "women" (n=1,369), "brca1" (n=1,276), "ovarian cancer" (n=1,259), "risk" (n=1,181), and "mutations" (n=929), which exposed the hotspots within the BRCA domain of breast cancer study.

Conclusion

The tendency in the BRCA research field over the past decade was presented by the scientometric analysis. The current research focus is the clinical trials of poly-adenosine diphosphate ribose polymerase inhibitors (PARPi) drugs and their resistance mechanisms.

Long non-coding RNA NPBWR1-2 affects the development of ovarian cancer via multiple microRNAs

Ovarian cancer has a high incidence rate and mortality in gynaecologic malignancies. Epithelial ovarian cancer (EOC) accounts for >95% of ovarian cancer cases. Most of the patients with EOC are difficult to diagnose in early stage. The aim of the present study was to compare the long non-coding (lnc)RNA expression profiles of five ovarian cancer cell lines (IGROV1, A2780, SKOV3, ES2, and Hey) and an ovarian epithelial cell line (IOSE80) in order to identify differentially expressed lncRNAs and their associated microRNAs (miRNAs). The expression profiles of lncRNAs and mRNAs in these cell lines were determined by microarray gene analysis and reverse transcription-quantitative PCR. lncRNA neuropeptides B and W receptor 1–2 (NPBWR1-2) overexpression was induced in the SKOV3 cell line. Cell viability, proliferation, migration, invasion and apoptosis were evaluated using MTT, colony-formation, Transwell and flow cytometry assays, respectively. The microarray results indicated that several lncRNAs were differentially expressed in the five ovarian cancer cell lines compared with the normal ovarian epithelial cell line. Compared with IOSE80, lncRNA NPBWR1-2 was downregulated by more than two-fold in all five ovarian cancer cell lines. Moreover, NPBWR1-2 overexpression in the SKOV3 cell line decreased cell viability, inhibited proliferation, migration and invasion, and promoted apoptosis compared with the control cells. A total of 20 miRNAs, which are involved in tumorigenesis and development, were predicted to be associated with NPBWR1-2 by bioinformatics analysis. The results of the present study suggest that lncRNA NPBWR1-2 affects the occurrence and development of ovarian cancer via multiple miRNAs, providing a theoretical basis for the development of novel clinical treatments.

MicroRNA-1179 regulates proliferation and chemosensitivity of human ovarian cancer cells by targeting the PTEN-mediated PI3K/AKT signaling pathway

INTRODUCTION

Owing to widespread roles of miRs, the dysregulation of their expression in human tissues has been linked with the development of several diseases such as cancer. The study was designed to investigate the role and therapeutic potential of miR-1179 in ovarian cancer.

MATERIAL AND METHODS

Proliferation rate was monitored by MTT assay. Transfections were performed using Lipofectamine 2000 reagent. Cell cycle apoptosis was detected by AO/EB and annexin V/PI staining. Expressions analysis was carried out by qRT-PCR and western blotting. In vivo evaluation was carried out in xenografted mouse models.

RESULTS

The results revealed that miR-1179 is considerably upregulated in ovarian cancer cell lines. Inhibition of miR-1179 triggers decrease in the viability via initiation of apoptotic cell death of ovarian PA-1 cancer cells. TargetScan analysis showed PTEN to be the main target of miR-1179 in PA-1 cells. Exploration of PTEN expression in ovarian cancer cell lines revealed up to 9-fold downregulation of PTEN. However, inhibition of miR-1179 in PA-1 cells resulted in upregulation of PTEN expression. In addition, overexpression of PTEN caused a reduction of PA-1 cell viability via induction of apoptotic cell death. However, silencing of miR-1179 could rescue the effects of miR-1179 inhibition on the proliferation of miR-1179. The miR-1179 suppression was accompanied by a significant decline in phosphorylation of PI3K and AKT expression in the PA-1 cells. The in vivo study showed that miR-1179 suppression inhibits the xenografted tumor growth.

CONCLUSIONS

The results of this study indicate that miR-1179 may prove to be an important therapeutic target for ovarian cancer.

A genome wide SNP genotyping study in the Tunisian population: specific reporting on a subset of common breast cancer risk loci

Background

Breast cancer is the most common cancer in women worldwide. Around 50% of breast cancer familial risk has been so far explained by known susceptibility alleles with variable levels of risk and prevalence. The vast majority of these breast cancer associated variations reported to date are from populations of European ancestry. In spite of its heterogeneity and genetic wealth, North-African populations have not been studied by the HapMap and the 1000Genomes projects. Thus, very little is known about the genetic architecture of these populations.

Methods

This study aimed to investigate a subset of common breast cancer loci in the general Tunisian population and to compare their genetic composition to those of other ethnic groups. We undertook a genome-wide haplotype study by genotyping 135 Tunisian subjects using the Affymetrix 6.0-Array. We compared Tunisian allele frequencies and linkage disequilibrium patterns to those of HapMap populations and we performed a comprehensive assessment of the functional effects of several selected variants.

Results

Haplotype analyses showed that at risk haplotypes on 2p24, 4q21, 6q25, 9q31, 10q26, 11p15, 11q13 and 14q32 loci are considerably frequent in the Tunisian population (> 20%). Allele frequency comparison showed that the frequency of rs13329835 is significantly different between Tunisian and all other HapMap populations. LD-blocks and Principle Component Analysis revealed that the genetic characteristics of breast cancer variants in the Tunisian, and so probably the North-African populations, are more similar to those of Europeans than Africans.

Using eQTl analysis, we characterized rs9911630 as the most strongly expression-associated SNP that seems to affect the expression levels of BRCA1 and two long non coding RNAs (NBR2 and LINC008854). Additional in-silico analysis also suggested a potential functional significance of this variant.

Conclusions

We illustrated the utility of combining haplotype analysis in diverse ethnic groups with functional analysis to explore breast cancer genetic architecture in Tunisia. Results presented in this study provide the first report on a large number of common breast cancer genetic polymorphisms in the Tunisian population which may establish a baseline database to guide future association studies in North Africa.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-5133-8) contains supplementary material, which is available to authorized users.

Expression and polymorphism of micro-RNA according to body mass index and breast cancer presentation in Tunisian patients

Micro-RNAs (miRs) constitute a class of small noncoding RNAs implicated in the regulation of gene expression by binding to target mRNAs. A miR can target several mRNAs, being involved in different biologic processes and pathologies. This pleiotropic function might explain the link between diseases co-occurrence. Epigenetic origin of the link between obesity and breast cancer (BC) is investigated in a cohort of Tunisian patients, focusing on polymorphism at germline level (miR-146a) and on expression in mammary tumors (miR-21, miR-146a, and miR-34a), according to body mass index (BMI) and clinico-pathologic features. The measure of miR expression in 60 mammary tumors was realized using quantitative RT-PCR. Study of rs 2910164 in miR-146a was performed by PCR and direct sequencing using blood DNA of 83 affected women and 50 unrelated subjects from Great Tunis. MiR-21, miR-146a, and miR-34a have been quantified in breast tumor according to BMI. MiR-21 is significantly more expressed in tumors of obese women comparatively to nonobese patients. On the contrary, miR-34a is decreased in tumors of obese women. Moreover, in obese BC patients, a significant increase in both miR-21 and miR-146a expression is revealed in cases with lymph node metastasis. The polymorphism at rs 2910164 (miR-146a) locus was not shown as a risk factor for BC. However the mutant CC genotype was revealed to be associated with a risk for bad outcome of the disease. Chronic inflammation in obese women would be linked to aggressive breast tumors via induction of oncomiRs overexpression and decrease of tumor suppressor miRs.

MicroRNA-1179 suppresses cell growth and invasion by targeting sperm-associated antigen 5-mediated Akt signaling in human non-small cell lung cancer

Accumulating evidence has identified microRNA-1179 (miR-1179) as a novel cancer-related miRNA that is dysregulated in multiple cancers and plays an important role in regulating cancer development and progression. However, little is known about the role of miR-1179 in non-small cell lung cancer (NSCLC). Thus, in the present study, we aimed to investigate the potential biological function and regulatory mechanism of miR-1179 in NSCLC. The results showed that decreased expression of miR-1179 expression was frequently detected in primary NSCLC tissues and cell lines. Overexpression of miR-1179 suppressed the growth and invasion of NSCLC cells in vitro while its inhibition promoted the opposite effect. Sperm-associated antigen 5 (SPAG5) was an identified as a target gene of miR-1179. Moreover, SPAG5 expression was increased in NSCLC cells and showed an inverse correlation with miR-1179 in NSCLC specimens. SPAG5 knockdown inhibited the growth and invasion of NSCLC cells, results that simulated a similar effect to miR-1179 overexpression. Mechanistic investigations showed that miR-1179 overexpression or SPAG5 knockdown significantly downregulated the activation of Akt signaling. Additionally, SPAG5 overexpression partially reversed the antitumor effect of miR-1179. Overall, our results demonstrated that miR-1179 inhibited the growth and invasion of NSCLC cells by targeting SPAG5 and inhibiting Akt, findings that highlight the importance of the miR-1179/SPAG5/Akt axis in the progression of NSCCL.