Scutellarin Inhibits Proliferation, Invasion, and Tumorigenicity in Human Breast Cancer Cells by Regulating HIPPO-YAP Signaling Pathway.
Hou Lengchen,Chen Lei,Fang Lin
Medical science monitor : international medical journal of experimental and clinical research
BACKGROUND The present study aimed to investigate the effects of Scutellarin on proliferation, invasion and tumorigenicity in human breast carcinoma MCF-7 cells and its associated molecular mechanisms. MATERIAL AND METHODS The MCF-7 cells were cultured with varies of concentrations of Scutellarin in vitro. The proliferation, invasion, and apoptosis of MCF-7 cells were studied via CCK-8 assay, transwell assay, and flow cytometry. In vivo expression of the HIPPO pathway key proteins YAP and p-YAP of MCF-7 cells were analyzed by immunohistochemistry. RESULTS The inhibition rates of Scutellarin-treated MCF-7 cells were 40.1%, 58.7%, and 70.6% for 24, 48, and 72 h, respectively. The MCF-7 cell proliferation was significantly inhibited by Scutellarin. Treating MCF-7 cells with Scutellarin led to invasion inhibition. The rates apoptotic cells were between 12.4±1.9% and 23.9±2.1% in 40-120 µM Scutellarin-administrated groups, which had a significant rise compared with the control group (7.8±1.9%, P<0.05). Scutellarin significantly inhibited MCF-7 xenograft tumor growth. Immunohistochemical analysis showed that the inhibition of tumor growth in Scutellarin-treated mice was associated with increased p-YAP and decreased YAP expression in vivo. CONCLUSIONS Scutellarin-treated breast carcinoma MCF-7 cells had significantly inhibited growth and induced apoptosis, which is associated with induction of autophagy through regulation of the HIPPO-YAP signaling pathway, providing support to the clinical use of Scutellarin-based medication to achieve optimized outcome in patients with breast carcinoma.
The transcriptional regulators TAZ and YAP direct transforming growth factor β-induced tumorigenic phenotypes in breast cancer cells.
Hiemer Samantha E,Szymaniak Aleksander D,Varelas Xaralabos
The Journal of biological chemistry
Uncontrolled transforming growth factor-β (TGFβ) signaling promotes aggressive metastatic properties in late-stage breast cancers. However, how TGFβ-mediated cues are directed to induce tumorigenic events is poorly understood, particularly given that TGFβ has clear tumor suppressing activity in other contexts. Here, we demonstrate that the transcriptional regulators TAZ and YAP (TAZ/YAP), key effectors of the Hippo pathway, are necessary to promote and maintain TGFβ-induced tumorigenic phenotypes in breast cancer cells. Interactions between TAZ/YAP, TGFβ-activated SMAD2/3, and TEAD transcription factors reveal convergent roles for these factors in the nucleus. Genome-wide expression analyses indicate that TAZ/YAP, TEADs, and TGFβ-induced signals coordinate a specific pro-tumorigenic transcriptional program. Importantly, genes cooperatively regulated by TAZ/YAP, TEAD, and TGFβ, such as the novel targets NEGR1 and UCA1, are necessary for maintaining tumorigenic activity in metastatic breast cancer cells. Nuclear TAZ/YAP also cooperate with TGFβ signaling to promote phenotypic and transcriptional changes in nontumorigenic cells to overcome TGFβ-repressive effects. Our work thus identifies cross-talk between nuclear TAZ/YAP and TGFβ signaling in breast cancer cells, revealing novel insight into late-stage disease-driving mechanisms.
Apigenin suppresses the stem cell-like properties of triple-negative breast cancer cells by inhibiting YAP/TAZ activity.
Li Ying-Wei,Xu Jian,Zhu Guo-Yuan,Huang Zhu-Juan,Lu Yan,Li Xian-Qian,Wang Neng,Zhang Feng-Xue
Cell death discovery
Triple-negative breast cancer (TNBC) remains a clinical challenge because of the absence of effective therapeutic targets. In TNBC, overexpression of YAP and TAZ correlates with bioactivities of cancer stem cells (CSCs), high histological grade, resistance to chemotherapy, and metastasis. Thus, YAP/TAZ may serve as potential therapeutic targets in TNBC. To identify YAP/TAZ inhibitors, in previous experiments, we screened a library of natural compounds by using YAP/TAZ luciferase reporter assay and identified apigenin as a potential inhibitor. In this study, we demonstrated that apigenin significantly suppressed the proliferation and migration of TNBC cells. Furthermore, we demonstrated that apigenin inhibited stemness features of TNBC cells in both in vitro and in vivo assays. Our mechanism study demonstrated that apigenin decreased YAP/TAZ activity and the expression of target genes, such as CTGF and CYR61, in TNBC cells. We also showed that apigenin disrupted the YAP/TAZ-TEADs protein-protein interaction and decreased expression of TAZ sensitized TNBC cells to apigenin treatment. Collectively, our studies suggest that apigenin is a promising therapeutic agent for the treatment of TNBC patients with high YAP/TAZ activity.