Chk1 suppression leads to a reduction in the enhanced radiation-induced invasive capability on breast cancer cells

Secreted S100A4 causes asthmatic airway epithelial barrier dysfunction induced by house dust mite extracts via activating VEGFA/VEGFR2 pathway

The airway epithelial barrier dysfunction plays a crucial role in pathogenesis of asthma and causes the amplification of downstream inflammatory signal pathway. S100 calcium binding protein A4 (S100A4), which promotes metastasis, have recently been discovered as an effective inflammatory factor and elevated in bronchoalveolar lavage fluid in asthmatic mice. Vascular endothelial growth factor-A (VEGFA), is considered as vital regulator in vascular physiological activities. Here, we explored the probably function of S100A4 and VEGFA in asthma model dealt with house dust mite (HDM) extracts. Our results showed that secreted S100A4 caused epithelial barrier dysfunction, airway inflammation and the release of T-helper 2 cytokines through the activation of VEGFA/VEGFR2 signaling pathway, which could be partial reversed by S100A4 polyclonal antibody, niclosamide and S100A4 knockdown, representing a potential therapeutic target for airway epithelial barrier dysfunction in asthma.

Exosomal delivery of 7SK long non-coding RNA suppresses viability, proliferation, aggressiveness and tumorigenicity in triple negative breast cancer cells

AIMS

RN7SK (7SK), a highly conserved non-coding RNA, serves as a transcription regulator via interaction with a few proteins. Despite increasing evidences which support the cancer-promoting roles of 7SK-interacting proteins, limited reports address the direct link between 7SK and cancer. To test the hypothetic suppression of cancer by overexpression of 7SK, the effects of exosomal 7SK delivery on cancer phenotypes were studied.

MATERIALS AND METHODS

Exosomes derived from human mesenchymal stem cells were loaded with 7SK (Exo-7SK). MDA-MB-231, triple negative breast cancer (TNBC), cell line was treated with Exo-7sk. Expression levels of 7SK were evaluated by qPCR. Cell viability was assessed via MTT and Annexin V/PI assays as well as qPCR assessment of apoptosis-regulating genes. Cell proliferation was evaluated by growth curve analysis, colony formation and cell cycle assays. Aggressiveness of TNBCs was evaluated via transwell migration and invasion assays and qPCR assessment of genes regulating epithelial to mesenchymal transition (EMT). Moreover, tumor formation ability was assessed using a nude mice xenograft model.

KEY FINDINGS

Treatment of MDA-MB-231 cells with Exo-7SK resulted in efficient overexpression of 7SK; reduced viability; altered transcription levels of apoptosis-regulating genes; reduced proliferation; reduced migration and invasion; altered transcription of EMT-regulating genes; and reduced in vivo tumor formation ability. Finally, Exo-7SK reduced mRNA levels of HMGA1, a 7SK interacting protein with master gene regulatory and cancer promoting roles, and its bioinformatically-selected cancer promoting target genes.

SIGNIFICANCE

Altogether, as a proof of the concept, our findings suggest that exosomal delivery of 7SK may suppress cancer phenotypes via downregulation of HMGA1.

ARHGEF19 promotes the growth of breast cancer in vitro and in vivo by the MAPK pathway

OBJECTIVE

To assess the expression of ARHGEF19 in human breast cancer, investigate its role in breast cancer, and clarify the mechanism.

METHODS

Bioinformatics analysis, immunoblot, quantitative PCR, and immunohistochemical (IHC) assays were performed to assess ARHGEF19 expression in breast cancer. CCK-8 and Edu assays were conducted to reveal its role in breast cancer cell proliferation. Flow cytometry (FCM) assays and immunoblot were performed to confirm its effects on breast cancer apoptosis. Immunoblot was also performed to clarify the mechanism. Finally, tumor growth assays were aimed to confirm the role of ARHGEF19 in mice.

RESULTS

We observed that ARHGEF19 was highly expressed in human breast cancer. ARHGEF19 promoted breast cancer cell growth in vitro, and suppressed apoptosis. In addition, we found that ARHGEF19 could activate the MAPK pathway in breast cancer cells. Our findings further confirmed that ARHGEF19 contributed to breast cancer growth in mice.

CONCLUSION

We observed that ARHGEF19 promoted the growth of breast cancer in vitro and in vivo via MAPK pathway, and presume it could serve as a breast cancer therapeutic target.