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Journal of Clinical & Experimental Pathology | ISSN: 2161-0681 | Volume 8
December 03-04, 2018 | Chicago, USA
American Pathology and Oncology Research
&
15
th
International Congress on
Microbial Genetics and Molecular Microbiology
International Conference on
ROS and miRNA signaling in ovarian cancer angiogenesis, tumor growth and treatment resistance
Ling-Zhi Liu
Uinversity of Iowa, USA
O
varian cancer represents the fifth leading cause of cancer-related death among women. However, the mechanisms of
ovarian cancer development and the treatment resistance remain to be elucidated. We found that ovarian cancer cells
generate higher levels of reactive oxygen species (ROS) through NOX4 overexpression compared to immortalized normal
ovarian epithelial cells, which are involved in inducing tumor growth and angiogenesis. More interestingly, ROS inhibit miR-
199a and miR-125b expression through increasing the promoter methylation of the miR-199a and miR-125b genes by DNA
methyltransferase 1, thus increasing their targets HER2 or/and HER3 expression in ovarian cancer cells to regulate tumor
angiogenesis. Cisplatin is commonly used in ovarian cancer treatment by inducing apoptosis in cancer cells as a result of
lethal DNA damage. The cytoprotective functions of autophagy in cancer cells have been suggested as a potential mechanism
for chemoresistance. We also demonstrated miR-152 as a new autophagy-regulating miRNA that plays a role in cisplatin
resistance. MiR-152 expression was dramatically downregulated in the cisplatin-resistant cell lines and in ovarian cancer
tissues associated with cisplatin resistance. Overexpression of miR-152 sensitized cisplatin-resistant ovarian cancer cells by
reducing cisplatin-induced autophagy, enhancing cisplatin-induced apoptosis and inhibition of tumor growth through its
direct target ATG14. Collectively, these data provide insights into novel mechanisms for ROS and miRNAs signaling in ovarian
cancer angiogenesis, tumor growth, and treatment resistance.
Biography
Ling-Zhi Liu has completed her MD, PhD in 2000 from China Medical University. She is an Associate Professor in the Department of Pathology, University of Iowa.
She has published more than 50 papers in high profiled journals and has been serving as an Editorial Board Member and Ad-hoc reviewers of several journals.
ling-zhi-liu@uiowa.eduLing-Zhi Liu, J Clin Exp Pathol 2018, Volume 8
DOI: 10.4172/2161-0681-C5-057