RESUMO
Coregulation of microRNAs (miRNAs) and cancer stem cells (CSCs) is very important in carcinogenesis. miR-127-5p is known to be downregulated in breast cancer. In this study, we aimed to investigate how boric acid (BA), known for its previously unstudied anti-cancer properties, would affect the expression of miR127-5p and genes responsible for breast cancer stem cells (BC-SCs) metastasis. BC-SCs were isolated from human breast cancer cells (MCF-7) by immunomagnetic cell separation and characterized with flow cytometry and sphere formation. The viability of BC-SCs and the determination of its IC50 value in response to boric acid (BA) were assessed via the MTT assay. Boric acid exhibited dose- and time-dependent inhibition of cell viability in cells. The IC50 doses of boric acid in MCF-7 cells and BC-SCs were 45.69 mM and 41.27 mM, respectively. The impact of BA on the expression of metastatic genes and miR127-5p was elucidated through RT-qPCR analysis. While the expression of the COL1A1 (p < 0.05) and VIM (p < 0.01) was downregulated, the expression of the miR-127-5p, ZEB1 (p < 0.01), CDH1 (p < 0.05), ITGB1 (p < 0.05), ITGA5 (p < 0.05), LAMA5 (p < 0.01), and SNAIL (p < 0.05), was up-regulated in dose-treated BC-SCs (p < 0.001) to the RT-qPCR results. Our findings suggest that boric acid could induce miR-127-5p expression. However, it cannot be said that it improves the metastasis properties of breast cancer stem cells.
RESUMO
Targeting lung cancer stem cells (LC-SCs) for metastasis may be an effective strategy against lung cancer. This study is the first on epithelial-mesenchymal transition (EMT) properties of boric acid (BA) in LC-SCs. LC-SCs were isolated using the magnetic cell sorting (MACS) method. Tumor-sphere formation and flow cytometry confirmed CSC phenotype. The cytotoxic effect of BA was measured by MTT analysis, and the effect of BA on EMT was examined by migration analysis. The expression levels of ZEB1, SNAIL1, ITGA5, CDH1, ITGB1, VIM, COL1A1, and LAMA5 genes were analyzed by RT-qPCR. E-cadherin, Collagen-1, MMP-3, and Vimentin expressions were analyzed immunohistochemically. Boric acid slightly reduced the migration of cancer cells. Increased expression of transcription factor SNAIL (p < 0.001), but not ZEB1, was observed in LC-SCs. mRNA expression levels of ITGB1 (p < 0.01), ITGA5 (p < 0.001), COL1A1 (p < 0.001), and LAMA5 (p < 0.001) increased; CDH1 and VIM decreased in LC-SCs. Moreover, while E-cadherin (p < 0.001) and Collagen-1 (p < 0.01) immunoreactivities significantly increased, MMP-3 (p < 0.001) and Vimentin (p < 0.01) immunoreactivities decreased in BA-treated LC-SCs. To conclude, the current study provided insights into the efficacy and effects of BA against LC-SCs regarding proliferation, EMT, and cell death for future studies.
RESUMO
DNA double-strand break (DSB) repair genes interact with tumor stemness- and resistance-associated processes in cancer stem cells (CSCs). Therefore, targeting DNA DSB genes in cancer treatment is important for the CSC phenotype. Although the anti-cancer effect of boric acid (BA) has been studied, its effect on DNA DSB is unclear. Moreover, no studies investigate BA's effects on DNA DSB of lung cancer stem cells (LC-SCs). To fill the gap, we aimed to assess the effects of BA on A549 cancer stem cells. CSCs were isolated from human non-small cell lung cancer cells (A549) and characterized by flow cytometry. Different concentrations of BA (at doses ranging from 1 to 100 mM) were applied to cancer stem cells. Cytotoxic activities were determined using the cell viability assay (MTT assay) at 24 and 48 h. Expression levels of DNA DSB genes that BRCA1, BRCA2, RAD51, KU70/80, ATM, and XRCC4 were evaluated by RT-qPCR. Additionally, immunofluorescence staining analysis was exploited for caspase-3 and E-cadherin. ATM expression increased significantly (p < 0.001). No significant change was observed in the expression of other genes. Moreover, BA up-regulated caspase-3 and E-cadherin expression. Consequently, we can say that BA affects DNA DSB and the apoptotic abilities of LC-SCs.
RESUMO
Breast cancer pathology ranks second in mortality among women worldwide due to the resistance of cancer stem cells in tumor tissue to radiotherapy and chemotherapy and their effective DNA damage response system (DDR). Targeting the expression of DNA double-strand break (DSB) repair genes in breast cancer stem cells (BC-SCs) is essential for facilitating their elimination with conventional therapies. This study aims to investigate the effects of boric acid (BA) on the expression of DNA DSB repair genes in BC-SCs, which has not been studied in the literature before. BS-SCs were isolated by the MACS method and characterized by flow cytometry. The effects of BA on BC-SCs' DNA DSB repair genes were deciphered by cell viability assay, inverted microscopy, and RT-qPCR. While the expression of the BRCA1 and BRCA2 was upregulated, the expression of the ATM (p < 0.001), RAD51 (p < 0.001), and KU70 (p < 0.001) was downregulated in dose-treated BC-SCs (p < 0.001) to the qPCR results. Consequently, BA affects some of the DNA DSB repair genes of breast cancer stem cells. Findings from this study could provide new insights into the potential therapeutic application of BA in BC-SC elimination and cancer intervention.