Hepatocellular carcinoma (HCC) develops synergistically in HCV-infected patients with alcoholism, and no treatments are available for this devastating complication. Our study reveals the role of TLR4-dependent Nanog+ cancer stem cells (CSCs) in liver oncogenesis induced by alcohol in HCV Ns5aTg mice. Defective TGF-2 signaling in 22 spectrin heterozygote (22sp+/-) mice, leads to aberrant IL-6 and Nanog induction and spontaneous HCC development. These two mechanistic concepts are merged by our recent findings that the Nanog+ CSCs have defective TGF-2 signaling, and 22sp+/- mouse livers have TLR4 induction. Further, CDK4 which is activated by TLR4 signaling, may disrupt TGF-2 signaling via its interaction with 22SP and Smad3, preventing Smad complex nuclear translocation. In fact, CDK4 haploinsufficiency (Cdk4+/-) attenuates HCC incidence in 22sp+/- mice, suggesting the causal role of CDK4 in inactivating TGF-2 pathway and consequently promoting liver oncogenesis. Based on these results, we propose a ground-breaking hypothesis that reciprocal regulation of heightened TLR4 oncogenic signaling and defective TGF-2 tumor suppressor pathway are causally linked via CDK4 to render synergistic liver oncogenesis. To test this hypothesis, we will exploit the use of the putative Nanog+ CSCs and cross-utilization of Ns5aTg, 22sp+/-, and Cdk4+/- mice and pursue the following specific aims: 1) to determine the role of activated CDK4 and defective TGF-2 signaling in TLR4-dependent oncogenic activity of the Nanog+ CSCs isolated from liver tumors of alcohol-fed HCV Ns5aTg mice;2) to test whether alcohol feeding increases HCC incidence in 22sp+/- mice in a manner dependent on TLR4;3) to test whether defective TGF-2 signaling aggravates TLR4-dependent liver oncogenesis in alcohol-fed Ns5aTg:22sp+/- compound mice;and 4) to determine whether CDK4 haploinsufficiency or a novel CDK4 inhibitor protects alcohol-fed Ns5aTg:22sp+/- mice from HCC. This program will meet the charge of the Recovery Act by immediately hiring 3 new full-time laboratory personnel and retaining 2 full-time scientists. Further, results from the proposed basic and pre-clinical studies will identify the interactive causal roles of CDK4, TGF-2 and TLR4 signaling in liver oncogenesis and will lead to the development of anti-CDK4, pro-TGF-2, and anti-TLR4 modalities for prevention and treatment of HCC, which itself holds enormous potential for an economic stimulus.

Public Health Relevance

The proposed collaborative research will test a ground-breaking mechanism of liver cancer development caused by alcohol and hepatitis virus infection with a main emphasis on convergence of two reciprocally affected signaling pathways. This research will identify new therapeutic targets for liver cancer caused by HCV and alcohol, leading to development of novel preventive and therapeutic drugs.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
High Impact Research and Research Infrastructure Programs (RC2)
Project #
1RC2AA019392-01
Application #
7853626
Study Section
Special Emphasis Panel (ZAA1-GG (02))
Program Officer
Gao, Peter
Project Start
2009-09-30
Project End
2011-08-31
Budget Start
2009-09-30
Budget End
2010-08-31
Support Year
1
Fiscal Year
2009
Total Cost
$990,970
Indirect Cost
Name
University of Southern California
Department
Pathology
Type
Schools of Medicine
DUNS #
072933393
City
Los Angeles
State
CA
Country
United States
Zip Code
90089
Chen, Jian; Shukla, Vivek; Farci, Patrizia et al. (2017) Loss of the transforming growth factor-? effector ?2-Spectrin promotes genomic instability. Hepatology 65:678-693
Chen, Jian; Raju, Gottumukkala S; Jogunoori, Wilma et al. (2016) Mutational Profiles Reveal an Aberrant TGF-?-CEA Regulated Pathway in Colon Adenomas. PLoS One 11:e0153933
Chen, Jian; Shukla, Vivek; Farci, Patrizia et al. (2016) Loss of the TGF-? Effector ?2SP Promotes Genomic Instability. Hepatology :
Chen, Jian; Herlong, Franklin H; Stroehlein, John R et al. (2016) Mutations of Chromatin Structure Regulating Genes in Human Malignancies. Curr Protein Pept Sci 17:411-37
Chen, Jian; Yao, Zhi-Xing; Chen, Jiun-Sheng et al. (2016) TGF-?/?2-spectrin/CTCF-regulated tumor suppression in human stem cell disorder Beckwith-Wiedemann syndrome. J Clin Invest 126:527-42
Machida, Keigo; Feldman, Douglas E; Tsukamoto, Hidekazu (2015) TLR4-dependent tumor-initiating stem cell-like cells (TICs) in alcohol-associated hepatocellular carcinogenesis. Adv Exp Med Biol 815:131-44
Tsukamoto, Hidekazu; Mishra, Lopa; Machida, Keigo (2014) Alcohol, TLR4-TGF-? antagonism, and liver cancer. Hepatol Int 8 Suppl 2:408-12
Muñoz, Nina M; Katz, Lior H; Shina, Ji-Hyun et al. (2014) Generation of a mouse model of T-cell lymphoma based on chronic LPS challenge and TGF-? signaling disruption. Genes Cancer 5:348-352
Chen, Chia-Lin; Tsukamoto, Hidekazu; Liu, Jian-Chang et al. (2013) Reciprocal regulation by TLR4 and TGF-? in tumor-initiating stem-like cells. J Clin Invest 123:2832-49
Katz, Lior H; Li, Ying; Chen, Jiun-Sheng et al. (2013) Targeting TGF-? signaling in cancer. Expert Opin Ther Targets 17:743-60

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