Browsing by Author "Bai, Shoumei"

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    EGFL6 regulates the asymmetric division, maintenance and metastasis of ALDH+ ovarian cancer cells
    (American Association for Cancer Research, 2016-11-01) Bai, Shoumei; Ingram, Patrick; Chen, Yu-Chih; Deng, Ning; Pearson, Alex; Niknafs, Yashar; O'Hayer, Patrick; Wang, Yun; Zhang, Zhong-Yin; Boscolo, Elisa; Bischoff, Joyce; Yoon, Euisik; Buckanovich, Ronald J; Biochemistry and Molecular Biology, School of Medicine
    Little is known about the factors that regulate the asymmetric division of cancer stem-like cells. Here we demonstrate that EGFL6, a stem cell regulatory factor expressed in ovarian tumor cells and vasculature, regulates ALDH+ ovarian cancer stem-like cells (CSC). EGFL6 signaled at least in part via the oncoprotein SHP2 with concomitant activation of ERK. EGFL6 signaling promoted the migration and asymmetric division of ALDH+ ovarian CSC. As such, EGFL6 increased not only tumor growth but also metastasis. Silencing of EGFL6 or SHP2 limited numbers of ALDH+ cells and reduced tumor growth, supporting a critical role for EGFL6/SHP2 in ALDH+ cell maintenance. Notably, systemic administration of an EGFL6-neutralizing antibody we generated restricted tumor growth and metastasis, specifically blocking ovarian cancer cell recruitment to the ovary. Together, our results offer a preclinical proof of concept for EGFL6 as a novel therapeutic target for the treatment of ovarian cancer.
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    Essential metabolic, anti-inflammatory, and anti-tumorigenic functions of miR-122 in liver
    (The Journal of Clinical Investigation, 2012-08-01) Hsu, Shu-hao; Wang, Bo; Kota, Janaiah; Yu, Jianhua; Costinean, Stefan; Kutay, Huban; Yu, Lianbo; Bai, Shoumei; La Perle, Krista; Chivukula, Raghu R.; Mao, Hsiaoyin; Wei, Min; Clark, K. Reed; Mendell, Jerry R.; Caligiuri, Michael A.; Jacob, Samson T.; Mendell, Joshua T.; Ghoshal, Kalpana
    miR-122, an abundant liver-specific microRNA (miRNA), regulates cholesterol metabolism and promotes hepatitis C virus (HCV) replication. Reduced miR-122 expression in hepatocellular carcinoma (HCC) correlates with metastasis and poor prognosis. Nevertheless, the consequences of sustained loss of function of miR-122 in vivo have not been determined. Here, we demonstrate that deletion of mouse Mir122 resulted in hepatosteatosis, hepatitis, and the development of tumors resembling HCC. These pathologic manifestations were associated with hyperactivity of oncogenic pathways and hepatic infiltration of inflammatory cells that produce pro-tumorigenic cytokines, including IL-6 and TNF. Moreover, delivery of miR-122 to a MYC-driven mouse model of HCC strongly inhibited tumorigenesis, further supporting the tumor suppressor activity of this miRNA. These findings reveal critical functions for miR-122 in the maintenance of liver homeostasis and have important therapeutic implications, including the potential utility of miR-122 delivery for selected patients with HCC and the need for careful monitoring of patients receiving miR-122 inhibition therapy for HCV.