👤 Gehan Safwat

Luminal breast cancer (LBC) is the most common subtype of breast cancer affecting women worldwide. Although luminal breast cancer typically has a better prognosis, it mostly responds poorly to neoadjuvant chemotherapy. Non-coding RNAs, especially long non-coding RNAs and microRNAs are crucial in regulating biological processes that contribute to breast cancer development. MALAT1, a long non-coding RNA, is pivotal in the progression of breast cancer. Epithelial-mesenchymal transition (EMT) is critical for cell movement during embryonic development. Clarifying this role could pave various avenues for developing innovative strategies for combating this subtype of malignancy. The present study aimed to investigate the expression profiles and clinical relevance of MALAT1 level and EMT-related miRNAs (miR-17-5p, miR-20a-5p, miR-93-5p, miR-135b-5p, and miR-146a-5p) alongside EMT markers (E-cadherin, N-cadherin, vimentin, fibronectin, twist, SNAI1, Slug, ZEB1, and ZEB2) in LBC patients. Fresh tissues were collected from fifty patients and twenty noncancerous controls. Differential expression of the markers was evaluated using qRT-PCR assay. Spearman Rho test assessed the relationship between the expression levels. Linear regression test evaluated the correlation between the parameters and various clinico-pathological features. Our results revealed an overall upregulation of MALAT1 in breast cancer tissues although this increase did not reach statistical significance. Overexpression of miR-20a-5p, miR-135b, and ZEB2 was reported, whereas miR146a-5p, ZEB1 and Vimentin levels were suppressed. Correlation analysis demonstrated that miR-20a-5p was positively correlated with SNAI1, E-cadherin, N-cadherin and Slug also it was significantly associated with family history and tumor laterality. Our findings suggest that miR-20a-5p plays an oncogenic role in luminal breast cancer by promoting EMT, while MALAT1 may contribute to disease progression through indirect regulatory mechanisms. Finally, MALAT1 and miR-20a-5p might serve as potential therapeutic and prognostic targets in LBC. Show less

Breast cancer is considered to be the most common cancer that affects women worldwide, where it accounts for approximately 38.8% of all cancer cases among females. Luminal subtypes are the most prevalent in Egypt. Small noncoding RNAs also called microRNAs (miRNAs) influence gene expression posttranscriptionally. Since they regulate the epithelial-mesenchymal transition process, which is vital for tumor invasion and metastasis, microRNAs play a critical role in the progression of cancer. This study has investigated the expression profiles of four microRNAs (miR-101-3p, miR-106a-5p, miR-106b-5p, and miR-130b-5p) and their impacts on genes associated with epithelial-mesenchymal transition (EMT) in luminal breast cancer. Tissue samples from 43 luminal breast cancer patients and 18 controls have been studied via real-time PCR (RT-qPCR). The association between the expression levels was evaluated using the Pearson correlation test. The correlation between the measured variables and numerous clinicopathological characteristics was assessed using the linear regression test. The results demonstrated that miR-101-3p, miR-106a-5p, and miR-106b-5p were significantly dysregulated, highlighting their possible role as oncogenes or tumor suppressors in the development of breast cancer. EMT markers, especially Twist, SNAI1, and E-cadherin, show significant alterations, indicating the activation of EMT pathways in luminal breast cancer. Correlation analysis showed interactions between miRNAs and EMT-related genes, showing a negative correlation between miR-101-3p and SNAI1, as well as a positive correlation between Twist and miR-106a-5p. Moreover, logistic regression analysis associated expression levels of those miRNAs with clinicopathological characteristics, such as body weight, age, and tumor laterality. These findings highlight the leading role of miR-101-3p and miR-106b-5p in the progression of luminal breast cancer via interacting with the EMT process and their potential as diagnostic, prognostic, and therapeutic targets. Show less