Prostate cancer is the second most common cause of cancer-related death among men in the United States. The PI3K-AKT-mTOR pathway is highly deregulated in prostate cancer. An outstanding and poorly understood question is the contribution of the most downstream signaling components of this pathway, 4EBP-eIF4E and p70S6Ks that control gene expression at the translation level towards prostate cancer development. The significance of this question is underscored by the tremendous therapeutic potential for targeting downstream translational components of mTOR signaling in human cancer. In this proposal, we employ a novel pharmacogenomic approach that will allow us to delineate specific steps in protein synthesis control that impinge on post-genomic control of prostate cancer development and therapeutic response, which has not been previously possible due to a lack of appropriate genetic and molecular tools. Specifically, we have designed and validated in vivo animal models to functionally restore the activity of 4EBP-eIF4E, p70S6K1 and rpS6 to normal levels in the setting of oncogenic mTOR hyperactivation. Furthermore, we will use the first ATP active site inhibitors of mTOR, which we have developed and characterized, to pharmacologically interrogate the downstream translational components of mTOR in prostate cancer initiation, progression and therapeutic response. In the context of PTEN-mediated prostatic intraepithelial neoplasia (PIN), our preliminary findings show that these inhibitors exhibit the strongest effect on aberrant mTOR dependent protein synthesis known to date and lead to the complete regression of this neoplastic lesion. This is further substantiated by the ability of these inhibitors to induce cell cycle arrest and programmed cell death in human prostate cancer cells. In addition, we have successfully optimized and employed a novel technology for examining translation of the prostate cancer genome, known as ribosome profiling (RP). This led to the first functional genome-wide analysis of the translational state of prostate cancer modulated by oncogenic mTOR signaling, which lays the groundwork for experiments proposed in this grant. Together, our current proposal, which utilizes a convergence of state-of-the-art genetic mouse models, novel mTOR inhibitors, and translation profiling, will provide an unprecedented level of insight into the post-genomic mechanisms of prostate cancer development dictated at the level of protein synthesis control. Moreover, these studies will identify novel functional biomarkers for mTOR hyperactivity that may aid in predicting clinical outcomes as well as provide the preclinical rationale for targeting the most downstream translational components of mTOR signaling in human prostate cancer.
Prostate cancer is the second-most prevalent type of cancer in American men, and is the cause of almost 30,000 deaths each year in the United States alone. The goal of this proposal is to use state-of-the-art genetic, pharmacological, and whole sequencing genome technologies to study the mechanisms by which dysfunction of specific components that control protein production lead to prostate tumor development. Our important findings will provide the rationale to usher in a new line of therapeutics that will specifically and effectively inhibit abnormal protein production towards treating prostate cancer.
|Chiu, Honyin; Jackson, Leandra V; Oh, Kwon Ik et al. (2018) The mTORC1/4E-BP/eIF4E Axis Promotes Antibody Class Switching in B Lymphocytes. J Immunol :|
|Forester, Craig M; Zhao, Qian; Phillips, Nancy J et al. (2018) Revealing nascent proteomics in signaling pathways and cell differentiation. Proc Natl Acad Sci U S A 115:2353-2358|
|Nguyen, Hao G; Conn, Crystal S; Kye, Yae et al. (2018) Development of a stress response therapy targeting aggressive prostate cancer. Sci Transl Med 10:|
|Truillet, Charles; Cunningham, John T; Parker, Matthew F L et al. (2017) Noninvasive Measurement of mTORC1 Signaling with 89Zr-Transferrin. Clin Cancer Res 23:3045-3052|
|So, Lomon; Lee, Jongdae; Palafox, Miguel et al. (2016) The 4E-BP-eIF4E axis promotes rapamycin-sensitive growth and proliferation in lymphocytes. Sci Signal 9:ra57|
|Truitt, Morgan L; Ruggero, Davide (2016) New frontiers in translational control of the cancer genome. Nat Rev Cancer 16:288-304|
|Sheridan, Christine Moore; Grogan, Tristan R; Nguyen, Hao G et al. (2015) YB-1 and MTA1 protein levels and not DNA or mRNA alterations predict for prostate cancer recurrence. Oncotarget 6:7470-80|
|Hsieh, Andrew C; Nguyen, Hao G; Wen, Lexiaochuan et al. (2015) Cell type-specific abundance of 4EBP1 primes prostate cancer sensitivity or resistance to PI3K pathway inhibitors. Sci Signal 8:ra116|
|Truitt, Morgan L; Conn, Crystal S; Shi, Zhen et al. (2015) Differential Requirements for eIF4E Dose in Normal Development and Cancer. Cell 162:59-71|
|Pelletier, Jerry; Graff, Jeremy; Ruggero, Davide et al. (2015) Targeting the eIF4F translation initiation complex: a critical nexus for cancer development. Cancer Res 75:250-63|
Showing the most recent 10 out of 25 publications