15-Lipoxygenase-2 (ALOX15B) is an arachidonic acid metabolizing enzyme that has been implicated as a functional tumor suppressor for prostate cancer. The expression and activity of 15-LOX-2 are frequently suppressed during carcinogenesis of prostate, lung, esophageal and sebaceous gland. Based on the observations that restoration of 15-LOX-2 expression in prostate cancer cells inhibited both DNA replication and tumor development, 15-LOX-2 has been proposed as a functional tumor suppressor for prostate cancer. However, it is unknown how 15-LOX-2 expression and functionality are suppressed in cancerous cells, the mechanism involved for 15-LOX-2 to suppress tumor formation, and whether or not 15-LOX-2 can be utilized as a therapeutic agent or an effector to attenuate or inhibit the disease progression. Our long term goal is to elucidate the role of 15-LOX-2 in prostate cancer and to develop targeted approach for prevention and treatment of cancer. The specific hypothesis behind the proposed research is that 15-LOX-2 is a major regulatory switch controlling tumor dormancy, and that loss of 15-LOX-2 contributes to prostate carcinogenesis.
The specific aims are: 1) to characterize ALOX15B mutations/polymorphisms in human prostate cancer using mutational and sequencing analysis of human ALOX15B loci in prostate tumor cells;2) to determine the functionality of tumor cell (tc)-15-LOX-2 in prostate cancer biology through a gain of function by expression of recombinant tc-15-LOX-2 protein or loss of function by ablation of endogenous expression of tc-15-LOX-2 using RNAi approach;and 3) to delineate the mechanistic link between 15-LOX-2 and VEGF expression using promoter deletion and mutation analysis. The proposed studies will significantly advance our understanding about 15-LOX-2, a functional tumor suppressor, in prostate cancer biology. The proposed studies will lead to a better understanding of the loss of 15-LOX-2 functionality as a tumor suppressor during prostate carcinogenesis, and the mechanism by which 15-LOX-2 keeps tumor suppressed.

Public Health Relevance

15-Lipoxygenase-2 (ALOX15B) is a newly identified functional tumor suppressor whose functionality is frequently suppressed in prostate cancer. The goals of this proposal are to examine the mutations/polymorphisms of 15-LOX-2 gene loci, to determine the routes of 15-LOX-2 suppression in prostate cancer, and to elucidate how 15-LOX-2 keeps prostate tumor suppressed in a latent stage. The studies will improve the risk assessment, detection, prevention, and treatment of prostate cancer, a major threat to public health and a financial burden to Medicare.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA131445-05
Application #
8310780
Study Section
Cancer Etiology Study Section (CE)
Program Officer
Yassin, Rihab R,
Project Start
2008-09-01
Project End
2014-07-31
Budget Start
2012-08-01
Budget End
2014-07-31
Support Year
5
Fiscal Year
2012
Total Cost
$214,879
Indirect Cost
$67,196
Name
Southern Illinois University School of Medicine
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
038415006
City
Springfield
State
IL
Country
United States
Zip Code
62794
Boral, Debasish; Nie, Daotai (2012) Cancer stem cells and niche mircoenvironments. Front Biosci (Elite Ed) 4:2502-14
Robbins, Gregory T; Nie, Daotai (2012) PPAR gamma, bioactive lipids, and cancer progression. Front Biosci (Landmark Ed) 17:1816-34
Malik, Babar; Nie, Daotai (2012) Cancer stem cells and resistance to chemo and radio therapy. Front Biosci (Elite Ed) 4:2142-9
Tang, Yong; Chen, Yakun; Jiang, Hongmei et al. (2010) Promotion of tumor development in prostate cancer by progerin. Cancer Cell Int 10:47
Yang, Dianer; Wang, Man-Tzu; Tang, Yong et al. (2010) Impairment of mitochondrial respiration in mouse fibroblasts by oncogenic H-RAS(Q61L). Cancer Biol Ther 9:122-33
Nie, Daotai (2010) Cancer stem cell and niche. Front Biosci (Schol Ed) 2:184-93
Zhang, Xuejing; Nie, Daotai; Chakrabarty, Subhas (2010) Growth factors in tumor microenvironment. Front Biosci (Landmark Ed) 15:151-65
Walia, Vijay; Ding, Ming; Kumar, Sumit et al. (2009) hCLCA2 Is a p53-Inducible Inhibitor of Breast Cancer Cell Proliferation. Cancer Res 69:6624-32
Tang, Yong; Wang, Man-Tzu; Chen, Yakun et al. (2009) Downregulation of vascular endothelial growth factor and induction of tumor dormancy by 15-lipoxygenase-2 in prostate cancer. Int J Cancer 124:1545-51
Chen, Yakun; Tang, Yong; Chen, Shuqing et al. (2009) Regulation of drug resistance by human pregnane X receptor in breast cancer. Cancer Biol Ther 8:1265-72