AUTHOR=Snigdha Kirti , Gangwani Karishma Sanjay , Lapalikar Gauri Vijay , Singh Amit , Kango-Singh Madhuri 

TITLE=Hippo Signaling in Cancer: Lessons From Drosophila Models

JOURNAL=Frontiers in Cell and Developmental Biology

VOLUME=7

YEAR=2019

URL=https://www.frontiersin.org/journals/cell-and-developmental-biology/articles/10.3389/fcell.2019.00085

DOI=10.3389/fcell.2019.00085

ISSN=2296-634X

ABSTRACT=<p>Hippo pathway was initially identified through genetic screens for genes regulating organ size in fruitflies. Recent studies have highlighted the role of Hippo signaling as a key regulator of homeostasis, and in tumorigenesis. Hippo pathway is comprised of genes that act as tumor suppressor genes like <italic>hippo</italic> (<italic>hpo</italic>) and <italic>warts</italic> (<italic>wts</italic>), and oncogenes like <italic>yorkie</italic> (<italic>yki</italic>). YAP and TAZ are two related mammalian homologs of <italic>Drosophila</italic> Yki that act as effectors of the Hippo pathway. Hippo signaling deficiency can cause YAP- or TAZ-dependent oncogene addiction for cancer cells. YAP and TAZ are often activated in human malignant cancers. These transcriptional regulators may initiate tumorigenic changes in solid tumors by inducing cancer stem cells and proliferation, culminating in metastasis and chemo-resistance. Given the complex mechanisms (e.g., of the cancer microenvironment, and the extrinsic and intrinsic cues) that overpower YAP/TAZ inhibition, the molecular roles of the Hippo pathway in tumor growth and progression remain poorly defined. Here we review recent findings from studies in whole animal model organism like <italic>Drosophila</italic> on the role of Hippo signaling regarding its connection to inflammation, tumor microenvironment, and other oncogenic signaling in cancer growth and progression.</p>