Colorectal cancer (CRC) is the second leading cause of cancer-related death in the U.S. and there has been a focused effort to understand the molecular basis of this malignancy, including its development, progression, and metastasis. Carcinogenesis is the consequence of cumulative and sequential genetic alterations. A more thorough understanding of the altered molecular pathways may contribute to improved strategies for prevention, screening, diagnosis and therapy. Genomic instability occurs when the cell is no longer capable of controlling its own mutation rate. Three separate pathways contribute to this imbalance, of which chromosomal instability (CIN) pathway is the most common, and is characterized by gains and/or losses of whole or portion of chromosomes. Among the factors that promote CIN is centrosome amplification, frequently manifested as abnormal centrosome numbers. The centrosomes are involved in a variety of cellular processes, including chromosome segregation during mitosis. Another important and life-threatening manifestation of cancer progression is metastasis, which occurs through a process involving epithelial-mesenchymal-transition (EMT). EMT allows a polarized epithelial cell to acquire a mesenchymal cell phenotype, which includes enhanced migratory capacity, invasiveness and elevated resistance to apoptosis. The full spectrum of molecular mechanisms that contribute to EMT of carcinoma cells remains unclear. The LONG-TERM GOAL of this project is to understand the molecular mechanisms responsible for the formation of colorectal cancer. The zinc finger-containing transcription factor Krppel-like factor 4 (KLF4) is expressed in the terminally differentiated intestinal epithelial cells. We have established that KLF4 is anti-proliferative and is essential for mediating the cell cycle checkpoint functions of p53 following DNA damage. KLF4 has been shown to be a potential tumor suppressor in CRC in both humans and in mouse models of intestinal tumorigenesis, and its genetic deletion results in centrosome amplification. Additionally, KLF4 was shown to be a suppressor of EMT in breast cancer cells. These findings indicate that KLF4 plays an important role in the pathogenesis of CRC, and advocates KLF4 as a potential suppressor of EMT in CRC. Based on these observations, we propose two HYPOTHESES that KLF4 (1) is a critical regulator of genomic stability and does so by regulating centrosome duplication and (2) is involved in suppressing EMT in CRC. We propose 2 SPECIFIC AIMS to test these hypotheses: (1) To determine the mechanisms by which KLF4 regulates centrosome duplication; (2) To correlate KLF4 levels with the levels of EMT markers in CRC and to determine whether KLF4 regulates EMT in CRC. These experiments will provide definitive evidence that KLF4 is a critical regulator of centrosome duplication and thus a suppressor of genetic instability in vitro and in vivo. Additionally, they will also establish KLF4 as a suppressor of EMT, and thus metastasis of colon cancer. The results will considerably advance the understanding of CRC formation and may posit KLF4 as a potential therapeutic target in colon cancer.

Public Health Relevance

Colon cancer is one of the leading causes of cancer-related death in the U. S. and is a major public health concern. In the funding period of the current grant, our group has continued to characterize the role of the zinc- finger transcription factor Krppel-like factor 4 (KLF4) as an important suppressor of colorectal cancer formation. The current proposal represents a continuing effort to understand the function of KLF4 in suppressing genomic instability and colorectal cancer metastasis. We anticipate that the experiments proposed in the next funding period will further increase the understanding of the mechanisms by which KLF4 inhibits the development and progression of colorectal cancer, and thus may help to provide novel insights towards the diagnosis, prevention or treatment of this lethal disease.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
2R01CA084197-17A1
Application #
8995416
Study Section
Clinical, Integrative and Molecular Gastroenterology Study Section (CIMG)
Program Officer
Mietz, Judy
Project Start
2000-01-01
Project End
2020-11-30
Budget Start
2015-12-01
Budget End
2016-11-30
Support Year
17
Fiscal Year
2016
Total Cost
Indirect Cost
Name
State University New York Stony Brook
Department
Type
Schools of Medicine
DUNS #
804878247
City
Stony Brook
State
NY
Country
United States
Zip Code
11794
He, Ping; Yang, Jong Won; Yang, Vincent W et al. (2018) Krüppel-like Factor 5, Increased in Pancreatic Ductal Adenocarcinoma, Promotes Proliferation, Acinar-to-Ductal Metaplasia, Pancreatic Intraepithelial Neoplasia, and Tumor Growth in Mice. Gastroenterology 154:1494-1508.e13
Nandan, Mandayam O; Bialkowska, Agnieszka B; Yang, Vincent W (2018) KLF5 mediates the hyper-proliferative phenotype of the intestinal epithelium in mice with intestine-specific endogenous K-RasG12D expression. Am J Cancer Res 8:723-731
Ghaleb, Amr M; Yang, Vincent W (2017) Krüppel-like factor 4 (KLF4): What we currently know. Gene 611:27-37
Kim, Chang-Kyung; He, Ping; Bialkowska, Agnieszka B et al. (2017) SP and KLF Transcription Factors in Digestive Physiology and Diseases. Gastroenterology 152:1845-1875
Kim, Chang-Kyung; Bialkowska, Agnieszka B; Yang, Vincent W (2016) Intestinal stem cell resurgence by enterocyte precursors. Stem Cell Investig 3:49
Snider, Ashley J; Bialkowska, Agnieszka B; Ghaleb, Amr M et al. (2016) Murine Model for Colitis-Associated Cancer of the Colon. Methods Mol Biol 1438:245-54
Ruiz de Sabando, Ainara; Wang, Chao; He, Yuanjun et al. (2016) ML264, A Novel Small-Molecule Compound That Potently Inhibits Growth of Colorectal Cancer. Mol Cancer Ther 15:72-83
Ghaleb, Amr M; Elkarim, Enas A; Bialkowska, Agnieszka B et al. (2016) KLF4 Suppresses Tumor Formation in Genetic and Pharmacological Mouse Models of Colonic Tumorigenesis. Mol Cancer Res 14:385-96
Wang, K; Xu, R; Snider, A J et al. (2016) Alkaline ceramidase 3 deficiency aggravates colitis and colitis-associated tumorigenesis in mice by hyperactivating the innate immune system. Cell Death Dis 7:e2124
Kuruvilla, Jes G; Kim, Chang-Kyung; Ghaleb, Amr M et al. (2016) Krüppel-like Factor 4 Modulates Development of BMI1(+) Intestinal Stem Cell-Derived Lineage Following ?-Radiation-Induced Gut Injury in Mice. Stem Cell Reports 6:815-824

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