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Background: Breast cancer has become a dangerous killer for the female, which seriously threatened women's life, leading to huge pressures to society. The present study assessed the mechanism underlying the involvement of bone marrow tyrosine kinase on chromosome X (BMX) in breast cancer development., Methods: The expression of BMX was examined by qPCR and immunohistochemistry. The effect of BMX on cell proliferation and migration was detected by Clone formation assay and Transwell assay. In vitro study, the correlation of BMX with Wnt/β-catenin pathway was explored by western blot and TOP/FOP flash assay., Results: In the present study, we found that BMX was up-regulated in breast cancer, which was associated with the tumor differentiation and TNM stage. Oncogenic BMX enhanced the ability of breast cancer cell proliferation and migration. Furthermore, BMX could up-regulate the protein expression levels of p-β-catenin (Y142), p-β-catenin(Y654) and inhibit the expression level of p-β-catenin (S33/37), thus activating Wnt/β-catenin pathway in MCF-7 and MDA-MB-231 cells. In addition, we revealed that BMX promoted GSK3β phosphorylation, which suppressed the degradation of β-catenin., Conclusions: In this study, we identified that BMX-activated Wnt/β-catenin signaling pathway, playing an oncogenic role in breast cancer, suggesting that BMX could become a potential treatment target of breast cancer.

Breast cancer is one of the most common malignant tumors worldwide. Metastasis remains the leading cause of death in breast cancer patients. Research on the mechanism of breast cancer metastasis has become a core issue in breast cancer research. Our previous series of studies have shown that VASP, as a key oncogene, plays an important role in the development of various tumors such as breast cancer. In this study, we find that miR-638 can target to inhibit VASP expression, and Lin28 acts as an RNA-binding protein to regulate the processing of miR-638, which inhibits its maturation and promotes the expression of VASP. In addition, we also find that CREB1 acts as a transcription factor that binds to the promoter of Lin28 gene and activates the Lin28/miR-638/VASP pathway. Furthermore, CREB1 can also directly bind to the promoter of VASP, and activate VASP expression, forming a CREB/Lin28/miR-638/VASP interactive network, which plays an important role in promoting cell proliferation and migration in breast cancer. Our study explained the mechanism of CREB1/Lin28/miR-638/VASP network promoting the development of breast cancer, which further elucidated the mechanism of VASP as a key oncogene, and also provided a theoretical basis for expanding new approaches to tumor biotherapy., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

The important role of LncRNA in the development of breast cancer is attracting more and more attention. In the previous study, we found that the expression level of LncRNA SNHG6 in breast cancer tissues and cells was significantly increased, but its mechanism in the development of breast cancer was still unclear. Our study found that knockdown of SNHG6 significantly inhibited the proliferation, migration and invasion of breast cancer cells MCF-7 and MDA-MB-231 cells. Further study showed that knockdown of SNHG6 significantly inhibited the expression level of VASP. More importantly, SNHG6 and VASP both can bind directly to miR-26a, suggesting that SNHG6 could act as a ceRNA to sponge miR-26a, thereby promoting the expression of VASP, which leading to activated proliferation, migration and invasion of breast cancer cells. Taken together, this study revealed the important role of the SNHG6/miR-26a/VASP regulatory network in the development of breast cancer, and provided a reference for exploring new pathogenesis and biomarkers of breast cancer., (Copyright © 2019 Elsevier GmbH. All rights reserved.)

Saikosaponin b2 (SSb2) can be extracted from Bupleurum spp. roots (Radix Bupleuri), which belongs to the Umbelliferae family. The current study aimed to explore the effects of SSb2 on proliferation of breast cancer cells and to identify the mechanism by which SSb2 affects breast cancer cell migration. mRNA expression levels of STAT3 and vasodilator‑stimulated phosphoprotein (VASP) were determined and increased expression was observed in 16 breast cancer tissues compared with the paracancerous tissues. MTT, wound healing, colony formation assays and western blot suggested that SSb2 inhibited MCF‑7 proliferation and migration. It was further identified by western blot analysis that SSb2 treatment reduced levels of phosphorylated STAT3, VASP, matrix metallopeptidase (MMP) 2 and MMP9 in MCF‑7 compared with the untreated cells. In addition, it was demonstrated that inhibition of STAT3 phosphorylation decreased VASP expression levels and induction of STAT3 phosphorylation increased VASP levels. Furthermore, it was observed that the treatment of Kunming mice with SSb2 at 30 mg/kg/day for 30 days induced no obvious changes in the liver or kidney tissues, as determined by haematoxylin and eosin staining. In conclusion, these results indicated that SSb2 may be a potential antitumor drug for the treatment of breast cancer, which acts by suppressing proliferation and migration by downregulating the STAT3 signalling pathway and inhibiting the expression of VASP, MMP2 and MMP9 expression.

Breast cancer was the highest incidence of tumor in women, which seriously threaten women's health. Our previous study found that the expression of IQUB (IQ motif and ubiquitin domain containing) was significantly increased in the development of breast cancer by transcriptome sequencing. However, there were no studies on the mechanism of IQUB in tumorigenesis. Further study showed that IQUB expression was significantly increased in breast cancer, which had a significantly positive correlation with pathological differentiation of breast cancer by tissue microarray analysis. Furthermore, we also discovered that IQUB overexpression could obviously promote the proliferation and migration of MCF-7 cells and increase the proportion of MCF-7 cells in S and G2/M phase in vitro study, while knockdown of IQUB caused inhibition of cell proliferation and migration in MDA-MB-231 cells and increased the proportion of MDA-MB-231 cells in G1 phase. Furthermore, IQUB overexpression or knockdown combined with treatment of Licl or MG-132 showed that IQUB activated Akt to promote GSK3β phosphorylation, which in turn activated Wnt/β-catenin signaling pathway in breast cancer cells. Taken together, these results indicated that upregulated IQUB promoted breast cancer cell proliferation and migration via activating Akt/GSK3β/β-catenin signaling pathway, which played an important part in the tumorigenesis and development of breast cancer., (© 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)