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MicroRNAs (miRNAs) are small, non-coding RNAs that regulate the expression level of the target genes in the cell. Breast cancer is responsible for the majority of cancer-related deaths among women globally. It has been proven that deregulated miRNAs may play an essential role in the progression of breast cancer. It has been shown in many cancers, including breast cancer, that aberrant expression of miRNAs may be associated with drug resistance. This study investigated the effect of let-7b-5p, detected by bioinformatics methods, on Dox resistance through the Aurora Kinase B (AURKB) gene. In silico analysis using publicly available miRNA expression, GEO datasets revealed that let-7b-5p significantly downregulated in BC. Further in silico studies revealed that of the genes among the potential targets of let-7b-5p, AURKB was the most negatively correlated and may be closely associated with Dox resistance. Expression analysis via quantitative PCR confirmed that let-7b-5p was downregulated and AURKB was upregulated in breast cancer tissue samples. Later, functional studies conducted with MCF-10A, MCF-7, and MDA-MB-231 cell lines demonstrated that let-7b-5p inhibits cancer cells through AURKB and sensitizes them to Dox resistance. In conclusion, it has been shown that the let-7b-5p/AURKB axis may be significant in breast cancer progression and the disruption in this axis may contribute to the trigger of Dox resistance. [ABSTRACT FROM AUTHOR]

Objective: Breast cancer (BC) is highly heterogeneous and one of the most common cancers. Luminal A (LUM A) is a subtype of BC with a better prognosis than other BC subtypes. The molecular mechanisms underlying the initiation and progression of the LUM A subtype are still unclear. Big data generated from microarray and sequencing systems can be re-analyzed, especially with the help of various in silico tools developed in recent years, and made applicable for in vitro and in vivo research. This work aimed to identify genes that may play a role in the progression of LUM A subtype of BC using both computational and laboratory-based methods. Materials and Methods: Overlapping genes associated with BC were identified from the The Cancer Genome Atlas database, GSE233242, GSE100925 geodata sets, and the geneshot tool. The network functional analysis between overlapping genes was determined with STRING 12.0. Expression levels of overlapping genes in BC were investigated with the TNMplot (https://tnmplot.com/analysis/) in silico tool. The effect of overlapping genes on the overall survival of LUM A cancer patients was defined using the Kaplan-Meier plotter tool. Expressions of genes identified using bioinformatics data were investigated via quantitative real-time-polymerase chain reaction (qRT-PCR) in LUM A tumor and adjacent tissue samples. The data were evaluated using the t-test. Both the sensitivity and specificity of selected genes have been determined using the receiver operating characteristic curve. Results: In silico investigation showed that eleven genes were possibly associated with BC. Among them CDC25A, AURKB, and TOP2A were considerably increased in LUM A samples according to qRT-PCR results. An overall survival analysis also showed that overexpression of these three genes could reduce the overall survival of LUM A patients. Conclusion: The genes CDC25A, AURKB, and TOP2A may play crucial functions in LUM A pathogenesis. Therapeutic strategies that diminish the expression of these connected genes may enhance the prognosis of LUM A patients. [ABSTRACT FROM AUTHOR]

Objective: Curcumin is considered an epigenetic regulator with anticancer effects. The micro-RNA (miRNA) miR-145-5p is a tumor suppressor that shows low expression levels in various cancers, including breast cancer (BC). This study aims to investigate whether curcumin inhibits MCF-7 human BC cell line proliferation and migration by regulating miR-145-5p and its possible target genes. Material and Method: MCF-7 cells were treated with curcumin and its solvent control. Additionally, cells were transfected with an miR-145-5p mimic and a non-targeting miRNA mimic. Cell viability was then evaluated, and the scratch wound assay was used to assess cell migration. The study predicts the miR-145- 5p putative target genes by searching for overlapping genes in the miRNet and miRTarBase v8 databases via the overexpressed genes in the BC tissue samples in the Cancer Genome Atlas (TCGA) datasets. Expression levels of miR-145-5p and the selected genes were detected using the quantitative real-time polymerase chain reaction (qRT-PCR). The 2-ΔΔCt method was used for the quantification analysis, with p<0.05 being considered statistically significant. Result: Curcumin treatment and overexpression of miR-145- 5p via the transfection of an miR-145-5p mimic significantly decreased the proliferation and migration of MCF-7 cells. Moreover, curcumin treatment significantly increased the expression of miR-145-5p. The possible target genes of miR-145- 5p (i.e., MCM2, MMP1, MMP9, EEF1A2) were downregulated in curcumin-treated MCF-7 cells. Additionally, miR-145-5p mimictransfected cells showed low expression levels of the MCM2, MMP1, and MMP9 genes. Conclusion: Curcumin inhibits the proliferation and migration of MCF-7 cells by acting on miR-145-5p and its possible target genes. [ABSTRACT FROM AUTHOR]

Anti-nuclear antibodies (ANAs) are autoantibodies synthesized in response to the cell nucleus contents and use as biomarkers of systemic autoimmune diseases. Inflammation, apoptosis and necrosis of the cells are consequences that accompany breast cancer against which autoantibodies will be produced. In this study, we aimed to evaluate the presence of ANAs and anti-extractable nuclear antigens (anti-ENAs) in breast cancer. A total of 33 luminal A and luminal B breast cancer patients were assessed for presence of ANAs and anti-ENAs. All the patients had received hormone therapy at least for 6 months before the tests. Patients were screened to ANAs by indirect immunofluorescence on human epithelial type 2 (HEp-2) cells. AESKUBLOTS® ANA-17 comp kit was used to identify the concentrations of U1-snRNP, snRNP/Sm, SmD1, dsDNA, SS-A/Ro 60, SS-A/Ro 52, SS-B/La antibodies. Fifteen (45.5%) patients were luminal A and 18 (54.5%) patients were luminal B. The median of age was 57 and the median of tumor size was 25. 19 (57.6%) patients had grade I or II and 14 (42.4%) had grade III. 3 patients had ANAs test positive. All the patients who had positive ANA test were luminal A breast cancer and had grade I or II tumors and positive lymph node, whereas, pathological tumor stage were varied. No statistically significant association was found between ANAs positivity and molecular subtype, age, body mass index (BMI), grade, tumor stage or lymph node involvement. Moreover, there were negative correlations between the anti-U1-snRNP and anti-dsDNA with Ki-67 and a correlation between anti-snRNP/Sm and anti-SS-A/Ro 52 was found. Comparing with luminal A, anti-U1-snRNP and antisnRNP/Sm concentrations were statistically significantly lower in luminal B tumors (p= 0.015 and 0.016 respectively). Patients who had high grade tumors showed low concentrations of anti-snRNP/Sm (p=0.027), whereas patients who had lymph node metastasis showed high concentrations of anti-U1-snRNP (p=0.031). ANAs positivity was more common in luminal A breast cancer patients compared with luminal B. Anti-U1-snRNP and anti-snRNP/Sm concentrations were lower in luminal B. Moreover, patients who had high grade tumors showed low concentrations of anti-snRNP/Sm, whereas those who had lymph node metastasis showed high concentrations of anti-U1-snRNP. [ABSTRACT FROM AUTHOR]

Objective: Recent research suggests curcumin extracted from the turmeric plant may inhibit the proliferation of cancer cells by controlling the expression of microRNAs (miRNAs). The effect of phenolic curcumin on miR-638-5p and potential target gene expressions in the triple negative breast cancer (TNBC) cell line MDA-MB-231 was investigated in this study. Materials and Methods: GSE154255 and GSE40525 datasets were downloaded and analyzed using GEO2R to identify dysregulated miRNAs in TNBC. To find differently expressed genes in breast cancer (BRCA), The Cancer Genome Atlas Program data was examined. Utilizing in silico tools, KEGG, GO, and other enrichment analyses were performed. The databases miRNet, miRTarBase v8.0, and TarBase v.8 were used for miRNA and mRNA matching. Real-time quantitative reverse transcription polymerase chain reaction was used to examine the levels of miRNA and its targets in miRNA mimic transfected/curcumin-treated MDA-MB-231 cultures and controls. The cell viability detection kit-8 method was used to assess cell viability, and the scratch assay was used to conduct migration assessment. Results: Bioinformatics analysis showed that miR-638-5p was significantly reduced in TNBC patients. Experimental results showed that miR-638-5p was upregulated in MDA-MB-231 treated with curcumin, while the potential target genes of miR-638-5p, CFL1, SIX4, MAZ, and CDH1 were downregulated. Mimic miR-638-5p transfection inhibited MDA-MB-231 cell proliferation and reduced migration and expression of CFL1, SIX4, and MAZ genes was decreased in mimic miR-638-5p transfected cells. Conclusion: These findings suggest that curcumin exerts its anticancer effects on MDA-MB-231 cells by modulating the expression of miR-638-5p and its possible target genes. [ABSTRACT FROM AUTHOR]

Objective: Tubular breast carcinoma (TBC) is a rare subtype of breast carcinoma (BC) with a good prognosis. In this study, we aimed to assess the clinicopathological characteristics of pure TBC (PTBC), analyze factors that may influence long-term prognosis, examine the frequency of axillary lymph node metastasis (ALNM), and discuss the need for axillary surgery in PTBC. Materials and Methods: Fifty-four Patients diagnosed with PTBC between January 2003 and December 2020 at Istanbul Faculty of Medicine were included. Clinicopathological, surgical, treatment, and overall survival (OS) data were analyzed. Results: A total of 54 patients with a mean age of 52.2 years were assessed. The mean size of the tumor was 10.6 mm. Four (7.4%) patients had not undergone axillary surgery, while thirty-eight (70.4%) had undergone sentinel lymph node biopsy and twelve (22.2%) had undergone axillary lymph node dissection (ALND). Significantly, four (33.3%) of those who had undergone ALND had tumor grade 2 (p = 0.020) and eight of them (66.7%) had ALNM. Fifty percent (50%) of patients who were treated with chemotherapy had grade 2 and multifocal tumors and ALNM. Moreover, the frequency of ALNM was higher in patients with tumor diameters greater than 10 mm. Median follow-up time was 80 months (12–220). None of the patients had locoregional recurrence, but one patient had systemic metastasis. Furthermore, five-year OS was 97.9%, while ten-year OS was 93.6%. Conclusion: PTBC is associated with favorable prognosis, good clinical outcomes and high survival rate, with rare recurrences and metastases. [ABSTRACT FROM AUTHOR]