LncRNA SEMA3B-AS1 suppresses the tumor-initiating characteristics of triple negative breast cancer via engaging in MLL4-mediated H3K4 trimethylation.

Long noncoding RNAs (lncRNAs) are crucial regulators of tumor-initiating cells (TICs) and hold particular importance in triple negative breast cancer (TNBC). Yet, the precise mechanisms by which TIC-associated lncRNAs influence TNBC remain unclear. Our research utilized The Cancer Genome Atlas Breast Cancer (BC) data set to identify prognostic lncRNAs. We then conducted extensive assays to explore their impact on the tumor-initiating phenotype of TNBC cells and the underlying mechanisms. Notably, we found that low expression of lncRNA SEMA3B-AS1 correlated with unfavorable survival in BC patients. SEMA3B-AS1 was also downregulated in TNBC and linked to advanced tumor stage. Functional experiments confirmed its role as a TIC-suppressing lncRNA, curtailing mammosphere formation, ALDH + TIC cell proportion, and impairing clonogenicity, migration, and invasion. Mechanistic insights unveiled SEMA3B-AS1's nuclear localization and interaction with MLL4 (mixed-lineage leukemia 4), triggering H3K4 methylation-associated transcript activation and thus elevating the expression of SEMA3B, a recognized tumor suppressor gene. Our findings emphasize SEMA3B-AS1's significance as a TNBC-suppressing lncRNA that modulates TIC behavior. This study advances our comprehension of lncRNA's role in TNBC progression, advocating for their potential as therapeutic targets in this aggressive BC subtype.

Single molecule chromogenic in situ hybridization assay for RNA visualization in fixed cells and tissues.

Visualization of gene expression at single RNA molecular level represents a great challenge to both imaging technologies and molecular engineering. Here we show a single molecule chromogenic in situ hybridization (smCISH) assay that enables counting and localizing individual RNA molecules in fixed cells and tissue under bright-field microscopy. Our method is based on in situ padlock probe assays directly using RNA as a ligation template and rolling circle amplification combined with enzyme catalyzed chromogenic reaction for amplification product visualization. We show potential applications of our method by detecting gene expression variations in single cells, subcellular localization information of expressed genes, and gene expression heterogeneity in formalin-fixed, paraffin-embedded tissue sections. This facile and straightforward method can in principle be applied to any type of RNA molecules in different samples.

Comparative analysis of surgical modalities for the gynecomastia treatment: efficiency and aesthetic outcomes.

This retrospective study rigorously compares the clinical efficacy of three surgical methodologies for treating gynecomastia while providing guidance for future surgical modality selection. We analyzed records of 77 gynecomastia patients treated between January 2015 and October 2022. Patients were categorized into three groups: Group A (subcutaneous gland resection via areola incision), Group B (liposuction combined with single-hole endoscopic gland resection), and Group C (liposuction combined with three-hole endoscopic gland resection). Parameters assessed included patient demographics, intraoperative bleeding, surgical duration, hospitalization duration, costs, postoperative drainage, complications, and patient satisfaction. Group A had significantly shorter operation time and lower cost than Groups B and C (P < 0.05). There were no significant differences in postoperative drainage (P > 0.05). Group A had a higher incidence of subcutaneous fluid complications. All groups achieved 100% overall postoperative efficiency. Group B demonstrated superior outcomes for scarring and patient satisfaction. All three surgical modalities effectively treat gynecomastia. Circumareolar incision subcutaneous gland resection is optimal for mild to moderate cases due to reduced operation time and cost. Liposuction with single-hole endoscopic gland resection and three-hole endoscopic gland resection offers fewer complications and discreet incisions. Notably, the liposuction and single-hole endoscopic approach yielded superior postoperative patient satisfaction, aligning with minimally invasive principles and warranting broad clinical application.

A novel disulfidptosis-associated expression pattern in breast cancer based on machine learning.

Background: Breast cancer (BC), the leading cause of cancer-related deaths among women, remains a serious threat to human health worldwide. The biological function and prognostic value of disulfidptosis as a novel strategy for BC treatment via induction of cell death remain unknown. Methods: Gene mutations and copy number variations (CNVs) in 10 disulfidptosis genes were evaluated. Differential expression, prognostic, and univariate Cox analyses were then performed for 10 genes, and BC-specific disulfidptosis-related genes (DRGs) were screened. Unsupervised consensus clustering was used to identify different expression clusters. In addition, we screened the differentially expressed genes (DEGs) among different expression clusters and identified hub genes. Moreover, the expression level of DEGs was detected by RT-qPCR in cellular level. Finally, we used the least absolute shrinkage and selection operator (LASSO) regression algorithm to establish a prognostic feature based on DEGs, and verified the accuracy and sensitivity of its prediction through prognostic analysis and subject operating characteristic curve analysis. The correlation of the signature with the tumor immune microenvironment and tumor stemness was analyzed. Results: Disulfidptosis genes showed significant CNVs. Two clusters were identified based on three DRGs (DNUFS1, LRPPRC, SLC7A11). Cluster A was found to be associated with better survival outcomes(p < 0.05) and higher levels of immune cell infiltration(p < 0.05). A prognostic signature of four disulfidptosis-related DEGs (KIF21A, APOD, ALOX15B, ELOVL2) was developed by LASSO regression analysis. The signature showed a good prediction ability. In addition, the prognostic signature in this study were strongly related to the tumor microenvironment (TME), tumor immune cell infiltration, tumor mutation burden (TMB), tumor stemness, and drug sensitivity. Conclusion: The prognostic signature we constructed based on disulfidptosis-DEGs is a good predictor of prognosis in patients with BC. This prognostic signature is closely related to TME, and its potential correlation provides clues for further studies.

Imaging of individual transcripts by amplification-based single-molecule fluorescence in situ hybridization.

An amplification-based single-molecule fluorescence in situ hybridization (asmFISH) assay is introduced that exploits improved probe design for highly specific imaging of individual transcripts in fixed cells and tissues. In this method, a pair of DNA ligation probes are ligated on RNA templates upon specific hybridization, followed by probe circularization based on enzymatic DNA ligation and rolling circle amplification for signal boosting. The method is more efficient and specific than the padlock probe assay for detection of the same RNA molecules and discrimination of single nucleotide polymorphisms. Moreover, asmFISH is a versatile method which can be applied not only to cultured cells, but also to fresh frozen and formalin-fixed, paraffin-embedded tissue sections.

Identification of Seven Cell Cycle-Related Genes with Unfavorable Prognosis and Construction of their TF-miRNA-mRNA regulatory network in Breast Cancer.

Breast cancer (BC), with complex tumorigenesis and progression, remains the most common malignancy in women. We aimed to explore some novel and significant genes with unfavorable prognoses and potential pathways involved in BC initiation and progression via bioinformatics methods. BC tissue-specific microarray datasets of GSE42568, GSE45827 and GSE54002, which included a total of 651 BC tissues and 44 normal breast tissues, were obtained from the Gene Expression Omnibus (GEO) database, and 124 differentially expressed genes (DEGs) were identified between BC tissues and normal breast tissues via R software and an online Venn diagram tool. Database for Annotation, Visualization and Integration Discovery (DAVID) software showed that 65 upregulated DEGs were mainly enriched in the regulation of the cell cycle, and Search Tool for the Retrieval of Interacting Genes (STRING) software identified the 39 closest associated upregulated DEGs in protein-protein interactions (PPIs), which validated the high expression of genes in BC tissues by the Gene Expression Profiling Interactive Analysis (GEPIA) tool. In addition, 36 out of 39 BC patients showed significantly worse outcomes by Kaplan-Meier plotter (KM plotter), and an additional Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that seven genes (cyclin E2 (CCNE2), cyclin B1 (CCNB1), cyclin B2 (CCNB2), mitotic checkpoint serine/threonine kinase B (BUB1B), dual-specificity protein kinase (TTK), cell division cycle 20 (CDC20), and pituitary tumor transforming gene 1 (PTTG1)) were markedly enriched in the cell cycle pathway. Analysis of the clinicopathological characteristics of hub genes revealed that seven cell cycle-related genes (CCRGs) were significantly highly expressed in four BC subtypes (luminal A, luminal B, HER2-positive and triple-negative (TNBC)), and except for the CCNE2 gene, high expression levels were significantly associated with tumor pathological grade and stage and metastatic events of BC. Furthermore, genetic mutation analysis indicated that genetic alterations of CCRGs could also significantly affect BC patients' prognosis. A quantitative real-time polymerase chain reaction (qRT-PCR) assay found that the seven CCRGs were significantly differentially expressed in BC cell lines. Integration of published multilevel expression data and a bioinformatics computational approach were used to predict and construct a regulation mechanism: a transcription factor (TF)-microRNA (miRNA)-messenger RNA (mRNA) regulation network. The present work is the first to construct a regulatory network of TF-miRNA-mRNA in BC for CCRGs and provides new insights into the molecular mechanism of BC.

CXCL10 mediates breast cancer tamoxifen resistance and promotes estrogen-dependent and independent proliferation.

Although 70% of estrogen receptor (ER)-positive breast cancer patients can benefit from tamoxifen therapy, the rapid development of tamoxifen resistance hampers the treatment advantage. In this investigation, we found that the serum level of CXCL10 in breast cancer patients was positively correlated with tumor size and ER status. Furthermore, GSE22220 dataset analysis demonstrated that CXCL10 expression in the tumor was correlated with tumor grade and lymphatic metastasis status, and Kaplan-Meier analysis indicated that patients with high CXCL10 expression had a poor prognosis. Estrogen-deprived MCF7 cells were transfected with CXCL10 luciferase reporter plasmid and treated with 10 nM estrogen. Luciferase reporter assay confirmed that CXCL10 was regulated by estrogen. CXCL10 promoted the proliferation of both parental MCF7 cells and tamoxifen-resistant (TamR) MCF7 cells through the AKT pathway, while CXCL10 inhibition restored the sensitivity of TamR cells to tamoxifen. All of these data indicate that CXCL10 could be utilized as a biomarker to predict the prognosis of breast cancer and as a therapeutic target to treat tamoxifen resistant cases.

Upregulated Long Non-Coding RNA LL22NC03-N64E9.1 Promotes the Proliferation and Migration of Human Breast Cancer Cells by Silencing Kruppel-Like Factor 2 Expression.

INTRODUCTION: Recently, the significant regulatory effects of lncRNAs on the oncogenesis and growth of tumor have been demonstrated by an increasing number of research projects. A previous study showed that LL22NC03-N64E9.1 could promote the development of colorectal cancer, especially via enhanced cell proliferation. Similarly, this lncRNA should have comparable functions in breast cancer (BC), which requires in-depth investigation. Therefore, this study was designed to explore the correlation of LL22NC03-N64E9.1 with BC. METHODS: qRT-PCR was used to assess the relative expression of LL22NC03-N64E9.1 in BC tissues. Cell viability examination and colony formation experiments were performed to investigate the role of LL22NC03-N64E9.1 in BC cell's proliferation. Transwell assays were used to explore the effects of LL22NC03-N64E9.1 on BC cell's migration. RNA immunoprecipitation, chromosome immunoprecipitation assay and rescue experiments were performed to analyze the association of LL22NC03-N64E9.1 with target proteins and genes in BC cells. RESULTS: We identified that LL22NC03-N64E9.1 is an oncogene, upregulated in BC, which was verified in a cohort of 48 pairs of BC tissues. Based on the loss-of-function experiments, silencing LL22NC03-N64E9.1 expression significantly inhibited malignancy progression. In terms of the mechanism, LL22NC03-N64E9.1 acted on the enhancer of zeste homolog 2 (EZH2) by direct binding, which promoted BC cell growth. Furthermore, in the promoters of KLF2, the trimethylation of H3K27 could be regulated by LL22NC03-N64E9.1 as the mediator. CONCLUSION: Relying on the LL22NC03-N64E9.1/EZH2/KLF2 pathway, the lncRNA LL22NC03-N64E9.1 was significantly associated with BC development and could, therefore, be a potential therapeutic target to block BC growth.

MicroRNA­126­3p inhibits the proliferation, migration, invasion, and angiogenesis of triple­negative breast cancer cells by targeting RGS3.

Triple­negative breast cancer (TNBC) is characterized by fast progression with high potential for metastasis, and poor prognosis. The dysregulation of microRNAs (miRNAs) occurring in the initiation or progression of cancers often leads to aberrant gene expression. The aim of the present study was to explore the function of miR­126 in TNBC cells. Expression levels of miR­126­3p were determined by quantitative real­time PCR. Then, the effects of miR­126­3p on migration, proliferation, invasion, and angiogenesis were assessed through in vitro experiments including Cell Counting Kit­8, colony formation, Transwell invasion and vasculogenic mimicry formation assays. One of the target genes for miR­126­3p predicted by TargetScan was confirmed by luciferase activity assay. Results indicated that miR­126­3p expression was reduced in TNBC cell lines. Functional assays revealed that miR­126­3p overexpression inhibited cell proliferation, migration, invasion, colony formation capacity and vasculogenesis by 1.2­, 1.8­, 2.3­, 2.0­ and 3.3­fold, respectively, compared to the miRNA­negative control group of MDA­MB­231 cells (P<0.001, respectively). In addition, the regulator of G­protein signaling 3 (RGS3) was hypothesized and validated as a direct target of miR­126­3p in TNBC. The proliferation, migration, invasion, colony formation capacity and vasculogenesis of MDA­MB­231 cells were significantly increased by 1.4­, 2.0­, 1.8­, 1.4­ and 3.2­fold, respectively, in cells transfected with pcDNA3.0­RGS3 compared to pcDNA3.0­negative control groups (P<0.001, respectively). The influence of miR­126­3p expression was reversed by RGS3 restoration. Collectively, the present study revealed that miR­126­3p plays a role as a tumor suppressor in regulating TNBC cell activities by targeting RGS3, indicating that the miR­126­3p/RGS3 axis may be a potential treatment target.