Triple-negative breast cancer (TNBC) is a malignant subtype of breast cancer with the absence of targeted therapy, resulting in poor prognosis in patients. Chemotherapy remains the mainstay of treatment for TNBC; however, development of drug resistance is the main obstacle for successful treatments. In recent years, long non-coding RNA (lncRNA) has been implicated in multiple biological functions in various diseases, particularly cancers. Accumulating evidence suggested that lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) expression is dysregulated in many human cancers and thus is a useful prognostic marker for cancer patients. Nevertheless, the mechanism of how NEAT1 confers drug resistance in TNBC is still largely unknown. We performed lncRNA profiling by the LncRNA Profiler qPCR Array Kit in normal control (NC) and breast cancers (BC) blood samples and further validated in a larger cohort of samples by qRT-PCR. Gene expression level and localization were investigated by qRT-PCR, western blotting, and immunofluorescence staining. Flow cytometric analysis was carried out to detect cancer stem cells. Functional studies were performed both in vitro and in vivo xenograft model. Among 90 lncRNAs, NEAT1 was highly expressed in the blood samples of breast cancer patients than in NC. In particular, the expression of NEAT1 was higher in TNBC tissues than other subgroups. Functional studies revealed that NEAT1 conferred oncogenic role by regulating apoptosis and cell cycle progression in TNBC cells. We identified that knockdown of NEAT1 sensitized cells to chemotherapy, indicating the involvement in chemoresistance. Importantly, shNEAT1 reduced stem cell populations such as CD44+/CD24−, ALDH+, and SOX2+, implicating that NEAT1 was closely related to cancer stemness in TNBC. Our data highlighted the roles of NEAT1 chemoresistance and cancer stemness, suggesting that it could be used as a new clinical therapeutic target for treating TNBC patients especially those with drug resistance.
There is a wide variety of kinds of lipids, and complex structures which determine the diversity and complexity of their functions. With the basic characteristic of water insolubility, lipid molecules are independent of the genetic information composed by genes to proteins, which determine the particularity of lipids in the human body, with water as the basic environment and genes to proteins as the genetic system. In this review, we have summarized the current landscape on hormone regulation of lipid metabolism. After the well-studied PI3K-AKT pathway, insulin affects fat synthesis by controlling the activity and production of various transcription factors. New mechanisms of thyroid hormone regulation are discussed, receptor α and β may mediate different procedures, the effect of thyroid hormone on mitochondria provides a new insight for hormones regulating lipid metabolism. Physiological concentration of adrenaline induces the expression of extrapituitary prolactin in adipose tissue macrophages, which promotes fat weight loss. Manipulation of hormonal action has the potential to offer a new therapeutic horizon for the global burden of obesity and its associated complications such as morbidity and mortality.
Breast cancer is one of the leading causes of mortality in females. Over the past decades, intensive efforts have been made to uncover the pathogenesis of breast cancer. Interleukin-6 (IL-6) is a pleiotropic factor which has a vital role in host defense immunity and acute stress. Moreover, a wide range of studies have identified the physiological and pathological roles of IL-6 in inflammation, immune and cancer. Recently, several IL-6 signaling pathway-targeted monoclonal antibodies have been developed for cancer and immune therapy. Combination of IL-6 inhibitory antibody with other pathways blockage drugs have demonstrated promising outcome in both preclinical and clinical trials. This review focuses on emerging studies on the strong linkages of IL-6/IL-6R mediated regulation of inflammation and immunity in cancer, especially in breast cancer.
Triple-negative breast cancer (TNBC) remains a poor prognostic factor for breast cancer since no effective targeted therapy is readily available. Our previous studies confirmed miR-199a-5p is a TNBC-specific circulating biomarker, however, its functional roles in breast cancer is largely unknown. Thus, we investigated the functional implication of miR-199a-5p in TNBC and its potential underlying mechanisms. MTT assay was performed to investigate the cell proliferation after transient transfection of miR-199a-5p in MDA-MB-231 cell line, followed by cell cycle analysis. Transwell invasion assay and wound healing assay were used to study the invasion and migration ability respectively. To further investigate the stemness-related characteristics of miR-199a-5p in breast cancer cells, single-cell clonogenic assay and aldehyde dehydrogenase (ALDH) assay were performed. 32 normal and 100 breast cancer patients’ plasma were recruited to identify the potential circulating markers by qPCR. Cell proliferation assay revealed significant inhibition after miR-199a-5p ectopic expression (p < 0.0001), as a result of decreased S phase (p = 0.0284), increased G0/G1 phase (p = 0.0260) and apoptosis (p = 0.0374). Invasiveness (p = 0.0005) and wound healing ability were also decreased upon miR-199a-5p overexpression. It significantly altered EMT-related genes expression, namely CDH1, ZEB1 and TWIST. Single-cell clonogenic assay showed decreased colonies in miR-199a-5p (p = 0.0182). Significant downregulation (p = 0.0088) and inhibited activity (p = 0.0390) of ALDH was observed in miR-199a-5p. ALDH1A3, which is the dominant isoform of ALDH, is significantly upregulated in breast cancer plasma especially in TNBC (p = 0.0248). PIK3CD was identified as a potential downstream target of miR-199a-5p. Taken together, we unraveled, for the first time, the tumor-suppressive role of miR-199a-5p in TNBC, which attributed to EMT and cancer stemness properties, providing a novel therapeutic options towards this aggressive disease.
Zinc finger protein X-linked (ZFX) is a zinc finger protein of Zfy family, which is highly conserved in vertebrates. This transcriptional regulator is not only highly expressed in embryonic stem cells (ESC) and hematopoietic stem cells, but is also upregulated in a number of human cancers where it is functional related to cell proliferation and survival. Hepatocellular carcinoma (HCC) is highly aggressive cancer that commonly resistant to most chemotherapies and displays stemness characteristics. In this study, we examined the expression of ZFX in HCC and its possible functional implications in liver tumorigenesis. Quantitative RT-PCR analysis showed common overexpressions of ZFX in 51.8% HCC tumors when compared with their adjacent nonmalignant liver (n = 43/83; p = 0.004). Inline with the pluripotency role of ZFX, we found silencing of ZFX readily inhibited self-renewal capability (p = 0.0022), colony formation ability (p < 0.0001) and cell proliferation (p < 0.0001) through G0/G1 cell cycle arrest of HCC cells (p = 0.0038). In addition, suppression of ZFX sensitized HCC cells to chemotherapeutic agent cisplatin (p < 0.0001). Further investigations suggested that ZFX bind on the promoter of two important mediators, namely Nanog and SOX-2, activating their expressions in HCC (p < 0.0001). Moreover, in vivo xenograft study demonstrated that overexpression of ZFX would promote the tumor growth (p = 0.031). Taken together, our results show, for the first time, commonly overexpressions of ZFX in HCC, where it likely contributes to the stemness and pluripotent behavior of this highly malignant cancer.