Colorectal cancer (CRC) is one of the most common and lethal cancers worldwide. Under physiological conditions, the Notch and Wing-less/Int (Wnt) signaling pathways modulate homeostasis and differentiation of the intestinal epithelium. In intestinal cancers, these pathways are frequently dysregulated. Canonical Wnt/?- catenin signaling pathway activation, with resultant high ?-catenin transcriptional activity, is frequently implicated in human CRC; however, there are currently no treatments targeting this pathway. Several points of crosstalk between Notch and Wnt pathways have been described in CRC. Thus, uncovering the molecular mechanisms of transcriptional networks governed by the Notch and Wnt/?-catenin pathways in intestinal tumorigenesis is significant for advancing scientific knowledge on cancer biology, and would potentially provide a window for new CRC therapeutics. The long-term goal of the proposed research is to identify how transcriptional machinery controls intestinal cell differentiation and how critical transcription factors contribute to intestinal tumorigenesis.
In Aims 1 and 2, using the novel transgenic mouse models and unbiased highthroughput RNA and DNA sequencing techniques, I have managed several parallel projects and multiinstitutional collaborations to understand the role of transcription factor Atoh1 (Atonal homolog 1), and its downstream target, SAM Pointed Domain ETS transcription Factor (SPDEF) in CRCs. The results from the proposed project are expected to significantly advance our current understanding of transcriptional machinery in CRCs. To extend my current knowledge and gain deeper insight into the biology of cancer, in Aim 3, I plan to pursue my postdoctoral studies in the direction of understanding how these extracellular components within the tumor microenvironment contribute to the program of cancer cell metastasis, a primary cause of cancerrelated fatality with CRCs, especially how these cells grow, invade, migrate, and resist treatment. Collectively, this training is customized to give me a comprehensive education in basic science research that will be extremely in achieving my long-term career goal of becoming an independent cancer researcher.

Public Health Relevance

The regulation of transcriptional networks is crucially important for maintaining the homeostasis of the intestinal epithelium and understanding the biological mechanisms responsible for regulating these homeostatic processes is critical in dissecting physiological changes contributing to intestinal diseases, such as colorectal cancers (CRCs). I propose a study that is designed to identify transcription factors that are necessary for cell differentiation and to decipher how these factors contribute to intestinal tumor suppression. My goal is to utilize the results from this project to identify potential therapeutic targets for the treatment of CRCs.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Project #
5K00CA212433-05
Application #
9976474
Study Section
Special Emphasis Panel (ZCA1)
Program Officer
Lim, Susan E
Project Start
2017-09-01
Project End
2021-08-31
Budget Start
2020-09-01
Budget End
2021-08-31
Support Year
5
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Stanford University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
009214214
City
Stanford
State
CA
Country
United States
Zip Code
94305
Santos, António J M; Lo, Yuan-Hung; Mah, Amanda T et al. (2018) The Intestinal Stem Cell Niche: Homeostasis and Adaptations. Trends Cell Biol 28:1062-1078