rheumatology-congress-physiology-2019-posters-abstracts

Page 43

December 9-10, 2019 | Barcelona, Spain

Volume 14

ARTHRITIS AND RHEUMATOLOGY

ANATOMY AND PHYSIOLOGY

International Conference on

Journal of Orthopaedics Trauma Surgery

and Related Research

Rheumatology Congress 2019 & Anatomy and Physiology 2019

December 09-10, 2019

J Orthop Trauma Surg Rel Res, ISSN: 1897-2276

Yes-associated protein (YAP) is a target for invasive breast carcinoma

Mohamed Ahmed Eladl

University of Sharjah, UAE

es-associated protein (YAP) is an oncoprotein encoded by YAP1 gene. Hippo pathway activation results in sequestration

of YAP in the cytoplasm and degradation. Whereas, when the Hippo pathway is deactivated, YAP is translocated into the

nucleus and promotes transcription of downstream genes stimulating growth and inhibiting apoptosis. Numerous studies showed

that overexpression of YAP induces epithelial-mesenchymal transition, inhibits apoptosis and increases cancer stem cells number

in-vitro

. Levels of YAP were found to be elevated in many human cancers and related to poorly differentiated tumors. Therefore,

YAP has emerged as a prime target for developing anti-cancer drugs. This study aims to investigate the immunohistochemical

expression of YAP in breast cancer tissue compared to benign tumors and normal breast tissue. The nuclear expression of YAP

was evaluated in six cases of benign fibroadenomas, 6 cases of in- situ ductal carcinomas, 6 cases of normal breast tissue samples

as well as 60 cases of invasive breast carcinoma, 57 ductal (IDC) and 3 lobular (ILC). Staining was analyzed and blindly scored.

Nuclear staining of more than 20% of the nuclei was considered positive. Cytoplasmic staining was scored according to its

intensity as (+1 mild, +2 moderate, +3 strong). The results were then correlated with grade, stage and hormone receptor positivity

in each of those tissues. All cases of normal, benign and in-situ carcinomas depicted no nuclear YAP expression. YAP expression

in these cases was mostly cytoplasmic and varied in expression between mild, moderate or strong. On the other hand, 60% of

invasive breast carcinomas cases showed positive nuclear staining suggesting that YAP is active in these tumors and could have

possible carcinogenic role. Our data showed that YAP is highly active in breast adenocarcinoma and suggest that further studies

are required to investigate the exact pathway responsible for YAP activation and its involvement in carcinogenesis.