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Hormone receptor-positive and HER2-negative breast cancer (HR+/HER2-BC) is the most common type with a favorable prognosis under endocrine therapy. However, it still demonstrates unpredictable progression and recurrences influenced by high tumoral diversity and microenvironmental status. To address these heterogeneous molecular characteristics of HR+/HER2-BC, we aimed to simultaneously characterize its transcriptomic landscape and genetic architecture at the same resolution. Using advanced single-cell RNA and DNA sequencing techniques together, we defined four distinct tumor subtypes. Notably, the migratory tumor subtype was closely linked to genomic alterations of EGFR, related to the tumor-promoting behavior of IL6-positive inflammatory tumor-associated fibroblast, and contributing to poor prognosis. Our study comprehensively utilizes integrated analysis to uncover the complex dynamics of this breast cancer subtype, highlighting the pivotal role of the migratory tumor subtype in influencing surrounding cells. This sheds light on potential therapeutic targets by offering enhanced insights for HR+/HER2-BC treatment. [ABSTRACT FROM AUTHOR]

Complex of platelet-derived growth factor (PDGF) isoforms and PDGF receptors have important functions in the regulation of growth and survival of various cell types. Herein, it was found that aberrant PDGFC expression is closely associated with survival rates in triple-negative breast cancer (TNBC) patients. In addition, PDGFC expression was identified to be significantly increased in TNBC cells unlike other subtypes such as PDGFA, PDGFB, and PDGFD. Apparently, the effects of specific PDGF receptor (PDGFR) inhibitors such as sunitinib and ponatinib on HCC1806 and Hs578T TNBC cells were investigated. Both inhibitors decreased cell viability in a dose-dependent manner. In addition, the inhibitors completely inhibited cell growth in both the cell lines and decreased the expression of matrix metalloproteinase-1 (MMP-1), one of the metastasis-related genes. Cell migration was also decreased by the inhibitors. Finally, the combined effects of the inhibitors with doxorubicin (DOX) were investigated. The results showed that the combination of two PDGFR inhibitors with DOX inhibited the growth of cells and enhanced the apoptotic cell death more uniformly than DOX. Consequently, it is demonstrated that PDGFR inhibitors, sunitinib and ponatinib hold the potential for effective treatment of TNBC. [ABSTRACT FROM AUTHOR]

WNT5A is abnormally increased in a variety of cancers including breast cancer and has an adverse effect on the prognosis. However, the biological function of WNT5A is not fully known in HER2-positive (HER2+) breast cancer. Using public clinical data, we analyzed disease-free survival (DFS) and distant metastasis-free survival (DMFS). Here, we found that abnormal WNT5A induction is a correlation with the poor prognosis of HER2+ breast cancer. WNT5A expression was also decreased by pan-HER inhibitor neratinib but not by trastuzumab. In addition, WNT5A augmented cell invasiveness of HER2+ breast-cancer cells. To find WNT5A-induced metastatic-related factors, we did a human cytokine array. The levels of GM-CSF and CXCL8 were significantly increased by WNT5A. CXCL8 also accelerated cell invasiveness in HCC1954 breast-cancer cells. The expression of CXCL8 induced by WNT5A has been significantly reduced by MEK inhibitor, binimetinib. Finally, we studied the effect of CXCR2 antagonist, SB225002, to verify the relevance of CXCL8 in WNT5A-induced cell invasion. As expected, we found that WNT5A-induced cell invasion is completely inhibited by SB225002. Taken together, we have demonstrated that WNT5A directly mediates cell invasion through the induction of CXCL8 and ultimately affects the survival rate of HER2+ breast cancer. [ABSTRACT FROM AUTHOR]

Chemoresistance is one of the major causes of therapeutic failure in breast cancer patients. In this study, the mechanism of chemoresistance in human triple-negative breast cancer (TNBC) cells (MDA-MB-231) induced by doxorubicin (DOX) gradient was investigated. These DOX-resistant cells showed higher drug efflux rate, increased anchorage-independent growth when cultured in suspension, and increased tumor-forming ability in nude mice, compared to the wild-type MDA-MB-231 cells. RNA sequencing analysis showed an increase in the expression of genes involved in membrane transport, antiapoptosis, and histone regulation. Kaplan-Meier plot analysis of TNBC patients who underwent preoperative chemotherapy showed that the relapse free survival (RFS) of patients with high HIST1H2BK (histone cluster 1 H2B family member k) expression was significantly lower than that of patients with low HIST1H2BK expression. Quantitative real-time PCR confirmed that the level of HIST1H2BK expression was increased in resistant cells. The cytotoxicity analysis showed that the DOX resistance of resistant cells was reduced by treatment with a histone deacetylase (HDAC) inhibitor. Our results suggest that, in DOX-resistant cells, HIST1H2BK expression can be rapidly induced by the high expression of genes involved in membrane transport, antiapoptosis, and histone regulation. In conclusion, chemoresistance in MDA-MB-231 cells can occur in a relatively short period by DOX gradient via this previously known mechanism of resistance, and DOX resistance is dependent on the specificity of resistant cells to HDAC. [ABSTRACT FROM AUTHOR]

Spheroids are recognized for replicating the physiological microenvironment of tumours. However, because of the lack of controllability of the spheroid size, the response to anticancer drugs is variable in conventional spheroid culture methods. In this paper, we describe a method to generate several hundreds of spheroids of various types of cancer cells including patient derived cancer cells (PDCs) using a microfluidic device with pillars (diameter: 40 μm, height: 70 μm, center-to-center distance: 140 μm), called a microfluidic pillar array (μFPA) device. About three hundred glioma (U87) spheroids were obtained in the μFPA device within 3 days, and about 90% of them ranged from 175 to 225 μm. These spheroids were more resistant to doxorubicin at 10 μM than U87 cells in a monolayer. The former showed higher expression of CD133, a cancer stem cell marker, than the latter. Hypoxia inducible factor-1α (HIF-1α), another cancer stem cell marker, was found in the nucleus of the former, but found in the cytoplasm of the cells in a monolayer. Drug responses of spheroids of another glioma cell line (U251) and triple negative breast cancer (TNBC) primary cells were also easily quantified by measuring changes in spheroid size at different concentrations of their respective drug on the μFPA device. The μFPA device can be a powerful platform for obtaining uniform spheroids and monitoring the drug response of cancer cells including PDCs. [ABSTRACT FROM AUTHOR]

Interleukin-1 (IL1) is a proinflammatory cytokine and promotes cancer cell proliferation and invasiveness in a diversity of cancers, such as breast and colon cancer. Here, we focused on the pharmacological effect of Entelon® (ETL) on the tumorigenesis of triple-negative breast cancer (TNBC) cells by IL1-alpha (IL1A). IL1A enhanced the cell growth and invasiveness of TNBC cells. We observed that abnormal IL1A induction is related with the poor prognosis of TNBC patients. IL1A also increased a variety of chemokines such as CCL2 and IL8. Interestingly, IL1A expression was reduced by the ETL treatment. Here, we found that ETL significantly decreased the MEK/ERK signaling pathway in TNBC cells. IL1A expression was reduced by UO126. Lastly, we studied the effect of ETL on the metastatic potential of TNBC cells. Our results showed that ETL significantly reduced the lung metastasis of TNBC cells. Our results showed that IL1A expression was regulated by the MEK/ERK- and PI3K/AKT-dependent pathway. Taken together, ETL inhibited the MEK/ERK and PI3K/AKT signaling pathway and suppressing the lung metastasis of TNBC cells through downregulation of IL1A. Therefore, we propose the possibility of ETL as an effective adjuvant for treating TNBC. [ABSTRACT FROM AUTHOR]