Oncology Commons^™

Xpo1 Blockade With Kpt-330 Promotes Apoptosis In Cutaneous T-Cell Lymphoma By Activating The P53-P21 And P27 Pathways, Nitin Chakravarti, Amy Boles, Rachel Burzinski, Paola Sindaco, Colleen Isabelle, Kathleen Mcconnell, Anjali Mishra, Pierluigi Porcu

Kimmel Cancer Center Faculty Papers

Dysregulated nuclear-cytoplasmic trafficking has been shown to play a role in oncogenesis in several types of solid tumors and hematological malignancies. Exportin 1 (XPO1) is responsible for the nuclear export of several proteins and RNA species, mainly tumor suppressors. KPT-330, a small molecule inhibitor of XPO1, is approved for treating relapsed multiple myeloma and diffuse large B-cell lymphoma. Cutaneous T-cell lymphoma (CTCL) is an extranodal non-Hodgkin lymphoma with an adverse prognosis and limited treatment options in advanced stages. The effect of therapeutically targeting XPO1 with KPT-330 in CTCL has not been established. We report that XPO1 expression is upregulated in …

Targeting The Αvβ3/Ngr2 Pathway In Neuroendocrine Prostate Cancer, Anna Testa, Fabio Quaglia, Nicole M. Naranjo, Cecilia E. Verrillo, Christopher D. Shields, Stephen Lin, Maxwell W. Pickles, Drini F. Hamza, Tami Von Schalscha, David A. Cheresh, Benjamin E Leiby, Qin Liu, Jianyi Ding, William K. Kelly, D. Craig Hooper, Eva Corey, Edward F. Plow, Dario C. Altieri, Lucia R. Languino

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Highly aggressive, metastatic, neuroendocrine prostate cancer, which typically develops from prostate cancer cells acquiring resistance to androgen deprivation therapy, is associated with limited treatment options and hence poor prognosis. We have previously demonstrated that the αVβ3 integrin is over-expressed in neuroendocrine prostate cancer. We now show that LM609, a monoclonal antibody that specifically targets the human αVβ3 integrin, hinders the growth of neuroendocrine prostate cancer patient-derived xenografts in vivo. Our group has recently identified a novel αVβ3 integrin binding partner, NgR2, responsible for regulating the expression of neuroendocrine markers and for inducing neuroendocrine differentiation in prostate cancer cells. Through in …

Scutellaria Baicalensis Enhances 5-Fluorouracil-Based Chemotherapy Via Inhibition Of Proliferative Signaling Pathways, Haizhou Liu, Hui Liu, Zhiyi Zhou, Jessica Chung, Guojing Zhang, Jin Chang, Robert A Parise, Edward Chu, John C Schmitz

Abington Jefferson Health Papers

Fluoropyridine-based chemotherapy remains the most widely used treatment for colorectal cancer (CRC). In this study, we investigated the mechanism by which the natural product Scutellaria baicalensis (Huang Qin; HQ) and one of its main components baicalin enhanced 5-fluorouracil (5-FU) antitumor activity against CRC. Cell proliferation assays, cell cycle analysis, reverse-phase protein array (RPPA) analysis, immunoblot analysis, and qRT-PCR were performed to investigate the mechanism(s) of action of HQ and its active components on growth of CRC cells. HQ exhibited in vitro antiproliferative activity against drug resistant human CRC cells, against human and mouse CRC cells with different genetic backgrounds and …

Ctpathway: A Crosstalk-Based Pathway Enrichment Analysis Method For Cancer Research, Haizhou Liu, Mengqin Yuan, Ramkrishna Mitra, Xu Zhou, Min Long, Wanyue Lei, Shunheng Zhou, Yu-E Huang, Fei Hou, Christine M. Eischen, Wei Jiang

Department of Cancer Biology Faculty Papers

Background: Pathway enrichment analysis (PEA) is a common method for exploring functions of hundreds of genes and identifying disease-risk pathways. Moreover, different pathways exert their functions through crosstalk. However, existing PEA methods do not sufficiently integrate essential pathway features, including pathway crosstalk, molecular interactions, and network topologies, resulting in many risk pathways that remain uninvestigated.

Methods: To overcome these limitations, we develop a new crosstalk-based PEA method, CTpathway, based on a global pathway crosstalk map (GPCM) with >440,000 edges by combing pathways from eight resources, transcription factor-gene regulations, and large-scale protein-protein interactions. Integrating gene differential expression and crosstalk effects in …

Cyclin D1 Restrains Oncogene-Induced Autophagy By Regulating The Ampk-Lkb1 Signaling Axis., Mathew C. Casimiro, Gabriele Disante, Agnese Di Rocco, Emanuele Loro, Claudia Pupo, Timothy G. Pestell, Sara Bisetto, Marco A. Velasco-Velázquez, Xuanmao Jiao, Zhiping Li, Christine M. Kusminski, Erin L. Seifert, Chenguang Wang, Daniel Ly, Bin Zheng, Che-Hung Shen, Philipp E. Scherer, Richard Pestell

Department of Cancer Biology Faculty Papers

Autophagy activated after DNA damage or other stresses mitigates cellular damage by removing damaged proteins, lipids, and organelles. Activation of the master metabolic kinase AMPK enhances autophagy. Here we report that cyclin D1 restrains autophagy by modulating the activation of AMPK. In cell models of human breast cancer or in a cyclin D1-deficient model, we observed a cyclin D1-mediated reduction in AMPK activation. Mechanistic investigations showed that cyclin D1 inhibited mitochondrial function, promoted glycolysis, and reduced activation of AMPK (pT172), possibly through a mechanism that involves cyclin D1-Cdk4/Cdk6 phosphorylation of LKB1. Our findings suggest how AMPK activation by cyclin D1 …

Dysregulated Gpcr Signaling And Therapeutic Options In Uveal Melanoma., Vivian Chua, Dominic Lapadula, Clinita Randolph, Jeffrey L. Benovic, Philip B. Wedegaertner, Andrew E. Aplin

Department of Biochemistry and Molecular Biology Faculty Papers

Uveal melanoma is the most common primary intraocular malignant tumor in adults and arises from the transformation of melanocytes in the uveal tract. Even after treatment of the primary tumor, up to 50% of patients succumb to metastatic disease. The liver is the predominant organ of metastasis. There is an important need to provide effective treatment options for advanced stage uveal melanoma. To provide the preclinical basis for new treatments, it is important to understand the molecular underpinnings of the disease. Recent genomic studies have shown that mutations within components of G protein-coupled receptor (GPCR) signaling are early events associated …

Co-Targeting Hgf/Cmet Signaling With Mek Inhibitors In Metastatic Uveal Melanoma., Hanyin Cheng, Vivian Chua, Connie Liao, Timothy J. Purwin, Mizue Terai, Ken Kageyama, Michael A. Davies, Takami Sato, Andrew E. Aplin

Department of Cancer Biology Faculty Papers

Patients with metastatic uveal melanoma usually die within 1 year of diagnosis, emphasizing an urgent need to develop new treatment strategies. The liver is the most common site of metastasis. Mitogen-activated protein kinase kinase (MEK) inhibitors improve survival in V600 BRAF-mutated cutaneous melanoma patients but have limited efficacy in patients with uveal melanoma. Our previous work showed that hepatocyte growth factor (HGF) signaling elicits resistance to MEK inhibitors in metastatic uveal melanoma. In this study, we demonstrate that expression of two BH3-only family proteins, Bim-EL and Bmf, contributes to HGF-mediated resistance to MEK inhibitors. Targeting HGF/cMET signaling with LY2875358, a …

Proteoglycan Neofunctions: Regulation Of Inflammation And Autophagy In Cancer Biology., Liliana Schaefer, Claudia Tredup, Maria A. Gubbiotti, Renato V. Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Inflammation and autophagy have emerged as prominent issues in the context of proteoglycan signaling. In particular, two small, leucine-rich proteoglycans, biglycan and decorin, play pivotal roles in the regulation of these vital cellular pathways and, as such, are intrinsically involved in cancer initiation and progression. In this minireview, we will address novel functions of biglycan and decorin in inflammation and autophagy, and analyze new emerging signaling events triggered by these proteoglycans, which directly or indirectly modulate these processes. We will critically discuss the dual role of proteoglycan-driven inflammation and autophagy in tumor biology, and delineate the potential mechanisms through which …

V-Src Oncogene Induces Trop2 Proteolytic Activation Via Cyclin D1., Xiaoming Ju, Xuanmao Jiao, Adam Ertel, Mathew C. Casimiro, Gabriele Disante, Shengqiong Deng, Zhiping Li, Agnese Di Rocco, Tingting Zhan, Adam Hawkins, Tanya Stoyanova, Sebastiano Andò, Alessandro Fatatis, Michael P. Lisanti, Leonard G. Gomella, Lucia R. Languino, Richard G. Pestell

Department of Cancer Biology Faculty Papers

Proteomic analysis of castration-resistant prostate cancer demonstrated the enrichment of Src tyrosine kinase activity in approximately 90% of patients. Src is known to induce cyclin D1, and a cyclin D1-regulated gene expression module predicts poor outcome in human prostate cancer. The tumor-associated calcium signal transducer 2 (TACSTD2/Trop2/M1S1) is enriched in the prostate, promoting prostate stem cell self-renewal upon proteolytic activation via a γ-secretase cleavage complex (PS1, PS2) and TACE (ADAM17), which releases the Trop2 intracellular domain (Trop2 ICD). Herein, v-Src transformation of primary murine prostate epithelial cells increased the proportion of prostate cancer stem cells as characterized by gene expression, …

Mitochondrial Akt Regulation Of Hypoxic Tumor Reprogramming., Young Chan Chae, Valentina Vaira, M. Cecilia Caino, Hsin-Yao Tang, Jae Ho Seo, Andrew V. Kossenkov, Luisa Ottobrini, Cristina Martelli, Giovanni Lucignani, Irene Bertolini, Marco Locatelli, Kelly G. Bryant, Jagadish C. Ghosh, Sofia Lisanti, Bonsu Ku, Silvano Bosari, Lucia R. Languino, David W. Speicher, Dario C. Altieri

Department of Cancer Biology Faculty Papers

Hypoxia is a universal driver of aggressive tumor behavior, but the underlying mechanisms are not completely understood. Using a phosphoproteomics screen, we now show that active Akt accumulates in the mitochondria during hypoxia and phosphorylates pyruvate dehydrogenase kinase 1 (PDK1) on Thr346 to inactivate the pyruvate dehydrogenase complex. In turn, this pathway switches tumor metabolism toward glycolysis, antagonizes apoptosis and autophagy, dampens oxidative stress, and maintains tumor cell proliferation in the face of severe hypoxia. Mitochondrial Akt-PDK1 signaling correlates with unfavorable prognostic markers and shorter survival in glioma patients and may provide an "actionable" therapeutic target in cancer.

Obesity-Induced Colorectal Cancer Is Driven By Caloric Silencing Of The Guanylin-Gucy2c Paracrine Signaling Axis., Jieru E. Lin, Francheska Colon-Gonzalez, Erik S. Blomain, Gilbert W. Kim, Amanda Aing, Brian Stoecker, Justin Rock, Adam E. Snook, Tingting Zhan, Terry M. Hyslop, Michal Tomczak, Richard S. Blumberg, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Obesity is a well-known risk factor for colorectal cancer but precisely how it influences risks of malignancy remains unclear. During colon cancer development in humans or animals, attenuation of the colonic cell surface receptor guanylyl cyclase C (GUCY2C) that occurs due to loss of its paracrine hormone ligand guanylin contributes universally to malignant progression. In this study, we explored a link between obesity and GUCY2C silencing in colorectal cancer. Using genetically engineered mice on different diets, we found that diet-induced obesity caused a loss of guanylin expression in the colon with subsequent GUCY2C silencing, epithelial dysfunction, and tumorigenesis. Mechanistic investigations …

Rac1 P29s Regulates Pd-L1 Expression In Melanoma., Ha Linh Vu, Sheera Rosenbaum, Timothy J. Purwin, Michael A. Davies, Andrew E. Aplin

Department of Cancer Biology Faculty Papers

Whole exome sequencing of cutaneous melanoma has led to the detection of P29 mutations in RAC1 in 5-9% of samples, but the role of RAC1 P29 mutations in melanoma biology remains unclear. Using reverse phase protein array analysis to examine the changes in protein/phospho-protein expression, we identified cyclin B1, PD-L1, Ets-1, and Syk as being selectively upregulated with RAC1 P29S expression and downregulated with RAC1 P29S depletion. Using the melanoma patient samples in TCGA, we found PD-L1 expression to be significantly increased in RAC1 P29S patients compared to RAC1 WT as well as other RAC1 mutants. The finding that PD-L1 …

Structure-Based Screen Identifies A Potent Small Molecule Inhibitor Of Stat5a/B With Therapeutic Potential For Prostate Cancer And Chronic Myeloid Leukemia., Zhiyong Liao, Lei Gu, Jenny Vergalli, Samanta A. Mariani, Marco De Dominici, Ravi K. Lokareddy, Ayush Dagvadorj, Puranik Purushottamachar, Peter A. Mccue, Edouard J. Trabulsi, Costas D. Lallas, Shilpa Gupta, Elyse Ellsworth, Shauna Blackmon, Adam Ertel, Paolo Fortina, Benjamin E. Leiby, Guanjun Xia, Hallgeir Rui, David T. Hoang, Leonard G Gomella, Gino Cingolani, Vincent Njar, Nagarajan Pattabiraman, Bruno Calabretta, Marja T. Nevalainen

Department of Cancer Biology Faculty Papers

Bypassing tyrosine kinases responsible for Stat5a/b phosphorylation would be advantageous for therapy development for Stat5a/b-regulated cancers. Here, we sought to identify small molecule inhibitors of Stat5a/b for lead optimization and therapy development for prostate cancer and Bcr-Abl-driven leukemias. In silico screening of chemical structure databases combined with medicinal chemistry was used for identification of a panel of small molecule inhibitors to block SH2 domain-mediated docking of Stat5a/b to the receptor-kinase complex and subsequent phosphorylation and dimerization. We tested the efficacy of the lead compound IST5-002 in experimental models and patient samples of two known Stat5a/b-driven cancers, prostate cancer and chronic …

Targeting Cell Cycle And Hormone Receptor Pathways In Cancer., C E S Comstock, M A Augello, J F Goodwin, R De Leeuw, M J Schiewer, W F Ostrander, R A Burkhart, A K Mcclendon, Peter Mccue, Edouard J. Trabulsi, Costas D. Lallas, Leonard G Gomella, Md, M M Centenera, Jonathan Brody, Md, L M Butler, W D Tilley, K E Knudsen, Phd

Department of Cancer Biology Faculty Papers

The cyclin/cyclin-dependent kinase (CDK)/retinoblastoma (RB)-axis is a critical modulator of cell cycle entry and is aberrant in many human cancers. New nodes of therapeutic intervention are needed that can delay or combat the onset of malignancies. The antitumor properties and mechanistic functions of PD-0332991 (PD; a potent and selective CDK4/6 inhibitor) were investigated using human prostate cancer (PCa) models and primary tumors. PD significantly impaired the capacity of PCa cells to proliferate by promoting a robust G1-arrest. Accordingly, key regulators of the G1-S cell cycle transition were modulated including G1 cyclins D, E and A. Subsequent investigation demonstrated the ability …

Cyclin D1 Determines Estrogen Signaling In The Mammary Gland In Vivo., Mathew C Casimiro, Chenguang Wang, Z Li, Gabriele Disante, Nicole E Willmart, Sankar Addya, Lei Chen, Yang Liu, Michael P. Lisanti, Richard Pestell

Department of Cancer Biology Faculty Papers

The CCND1 gene, which is frequently overexpressed in cancers, encodes the regulatory subunit of a holoenzyme that phosphorylates the retinoblastoma protein. Although it is known that cyclin D1 regulates estrogen receptor (ER)α transactivation using heterologous reporter systems, the in vivo biological significance of cyclin D1 to estrogen-dependent signaling, and the molecular mechanisms by which cyclin D1 is involved, are yet to be elucidated. Herein, genome-wide expression profiling conducted of 17β-estradiol-treated castrated virgin mice deleted of the Ccnd1 gene demonstrated that cyclin D1 determines estrogen-dependent gene expression for 88% of estrogen-responsive genes in vivo. In addition, expression profiling of 17β-estradiol-stimulated cyclin …

The Tweak Receptor Fn14 Is A Therapeutic Target In Melanoma: Immunotoxins Targeting Fn14 Receptor For Malignant Melanoma Treatment., Hong Zhou, Suhendan Ekmekcioglu, John W Marks, Khalid A Mohamedali, Kaushal Asrani, Keeley K Phillips, Sharron A N Brown, Emily Cheng, Michele B Weiss, Walter N Hittelman, Nhan L Tran, Hideo Yagita, Jeffrey A Winkles, Michael G Rosenblum

Department of Cancer Biology Faculty Papers

Fibroblast growth factor-inducible protein 14 (Fn14), the cell surface receptor for tumor necrosis factor-like weak inducer of apoptosis (TWEAK), is overexpressed in various human solid tumor types and can be a negative prognostic indicator. We detected Fn14 expression in ∼60% of the melanoma cell lines we tested, including both B-Raf WT and B-Raf(V600E) lines. Tumor tissue microarray analysis indicated that Fn14 expression was low in normal skin, but elevated in 173/190 (92%) of primary melanoma specimens and in 86/150 (58%) of melanoma metastases tested. We generated both a chemical conjugate composed of the recombinant gelonin (rGel) toxin and the anti-Fn14 …

Gsk3Β Inhibition Blocks Melanoma Cell/Host Interactions By Downregulating N-Cadherin Expression And Decreasing Fak Phosphorylation., Jobin K John, Kim H T Paraiso, Vito W Rebecca, Liliana P Cantini, Ethan V Abel, Nicholas Pagano, Eric Meggers, Rahel Mathew, Clemens Krepler, Victoria Izumi, Bin Fang, John M Koomen, Jane L Messina, Meenhard Herlyn, Keiran S M Smalley

Department of Cancer Biology Faculty Papers

This study addresses the role of glycogen synthase kinase (GSK)-3β signaling in the tumorigenic behavior of melanoma. Immunohistochemical staining revealed GSK3β to be focally expressed in the invasive portions of 12 and 33% of primary and metastatic melanomas, respectively. GSK3 inhibitors and small interfering RNA (siRNA) knockdown of GSK3β were found to inhibit the motile behavior of melanoma cells in scratch wound, three-dimensional collagen-implanted spheroid, and modified Boyden chamber assays. Functionally, inhibition of GSK3β signaling was found to suppress N-cadherin expression at the messenger RNA and protein levels, and was associated with decreased expression of the transcription factor Slug. Pharmacological …

Trop-2 Inhibits Prostate Cancer Cell Adhesion To Fibronectin Through The Β1 Integrin-Rack1 Axis., Marco Trerotola, Jing Li, Saverio Alberti, Lucia R. Languino

Department of Cancer Biology Faculty Papers

Trop-2 is a transmembrane glycoprotein upregulated in several human carcinomas, including prostate cancer (PrCa). Trop-2 has been suggested to regulate cell-cell adhesion, given its high homology with the other member of the Trop family, Trop-1/EpCAM, and its ability to bind the tight junction proteins claudin-1 and claudin-7. However, a role for Trop-2 in cell adhesion to the extracellular matrix has never been postulated. Here, we show for the first time that Trop-2 expression in PrCa cells correlates with their aggressiveness. Using either shRNA-mediated silencing of Trop-2 in cells that endogenously express it, or ectopic expression of Trop-2 in cells that …

Cyclin D1 Induces Chromosomal Instability., Mathew C Casimiro, Richard Pestell

Department of Cancer Biology Faculty Papers

We developed mouse model systems to investigate the potential for cyclin D1 to induce CIN in vivo. In a mammary gland specific Tet-inducible model the acute expression profile regulated by cyclin D1 after 7 days was enriched in genes that rank highly with CIN. We also used a mammary gland targeted model (MMTV) to continuously express cyclin D1. The mice started to develop mammary gland tumors at 400 days and the tumor-free incidence was 40% in MMTV-cyclin D1. The gene expression profile of the tumors showed enrichment for the CIN signature. We next compared cyclin D1 expression and the highest …

Inflammatory Signaling Compromises Cell Responses To Interferon Alpha., W-C Huangfu, J Qian, C Liu, J Liu, A E Lokshin, D P Baker, H Rui, S Y Fuchs

Department of Cancer Biology Faculty Papers

Interferon alpha (IFNα) is widely used for treatment of melanoma and certain other malignancies. This cytokine as well as the related IFNβ exerts potent anti-tumorigenic effects; however, their efficacy in patients is often suboptimal. Here, we report that inflammatory signaling impedes the effects of IFNα/β. Melanoma cells can secrete pro-inflammatory cytokines that inhibit cellular responses to IFNα/β via activating the ligand-independent pathway for the phosphorylation and subsequent ubiquitination and accelerated degradation of the IFNAR1 chain of type I IFN receptor. Catalytic activity of the p38 protein kinase was required for IFNAR1 downregulation and inhibition of IFNα/β signaling induced by proinflammatory …

Gene Expression Signatures Modulated By Epidermal Growth Factor Receptor Activation And Their Relationship To Cetuximab Resistance In Head And Neck Squamous Cell Carcinoma., Elana J Fertig, Qing Ren, Haixia Cheng, Hiromitsu Hatakeyama, Adam Dicker Md, Phd, Ulrich Rodeck, Michael Considine, Michael F Ochs, Christine H Chung

Department of Radiation Oncology Faculty Papers

BACKGROUND: Aberrant activation of signaling pathways downstream of epidermal growth factor receptor (EGFR) has been hypothesized to be one of the mechanisms of cetuximab (a monoclonal antibody against EGFR) resistance in head and neck squamous cell carcinoma (HNSCC). To infer relevant and specific pathway activation downstream of EGFR from gene expression in HNSCC, we generated gene expression signatures using immortalized keratinocytes (HaCaT) subjected to ligand stimulation and transfected with EGFR, RELA/p65, or HRASVal12D.

RESULTS: The gene expression patterns that distinguished the HaCaT variants and conditions were inferred using the Markov chain Monte Carlo (MCMC) matrix factorization algorithm Coordinated Gene Activity …

Erk2 Phosphorylation Of Serine 77 Regulates Bmf Pro-Apoptotic Activity., Y Shao, A E Aplin

Department of Cancer Biology Faculty Papers

B-cell lymphoma 2 (Bcl-2) homology 3 (BH3)-only proteins represent a class of pro-apoptotic factors that neutralize pro-survival Bcl-2 proteins, and, in some cases, directly activate Bax. The mechanisms of control and the role of BH3-only proteins, such as Bcl-2 like protein 11 extra large and Bad are well studied. By contrast, relatively little is known about the regulation and role of Bcl-2 modifying factor (Bmf). The B-RAF oncogene is mutated in ∼8% of human tumors. We have previously shown that Bmf is upregulated at the transcript level and is required for apoptosis induced by targeting B-RAF signaling in tumor cells …

Vimentin Is A Novel Akt1 Target Mediating Motility And Invasion., Q-S Zhu, K Rosenblatt, K-L Huang, G Lahat, R Brobey, S Bolshakov, T Nguyen, Z Ding, R Belousov, K Bill, X Luo, A Lazar, Adam Dicker, Md, Phd, G B Mills, M-C Hung, D Lev

Department of Radiation Oncology Faculty Papers

The PI3K/AKT signaling pathway is aberrant in a wide variety of cancers. Downstream effectors of AKT are involved in survival, growth and metabolic-related pathways. In contrast, contradictory data relating to AKT effects on cell motility and invasion, crucial prometastatic processes, have been reported pointing to a potential cell type and isoform type-specific AKT-driven function. By implication, study of AKT signaling should optimally be conducted in an appropriate intracellular environment. Prognosis in soft-tissue sarcoma (STS), the aggressive malignancies of mesenchymal origin, is poor, reflecting our modest ability to control metastasis, an effort hampered by lack of insight into molecular mechanisms driving …

C-Jun Inhibits Mammary Apoptosis In Vivo., Sanjay Katiyar, Mathew C Casimiro, Luis Dettin, Xiaoming Ju, Erwin F Wagner, Hirokazu Tanaka, Richard Pestell

Department of Cancer Biology Faculty Papers

c-jun, which is overexpressed in a number of human cancers encodes a critical component of the AP-1 complex. c-jun has been shown to either induce or inhibit cellular apoptosis. Germ line deletion of both c-jun alleles is embryonically lethal. To determine the role of the endogenous c-jun gene in apoptosis, we performed mammary epithelial cell-targeted somatic deletion using floxed c-jun (c-jun(f/f)) conditional knockout mice. Laser capture microdissection demonstrated endogenous c-jun inhibits expression of apoptosis inducing genes and reactive oxygen species (ROS)-reducing genes (MnSOD, catalase). ROS have been implicated in apoptosis and undergo enzymatic elimination via MnSOD and CuZnSOD with further …

Regulation Of Cellular Protein Phosphatase-1 (Pp1) By Phosphorylation Of The Cpi-17 Family, C-Kinase-Activated Pp1 Inhibitors., Masumi Eto

Department of Molecular Physiology and Biophysics Faculty Papers

The regulatory circuit controlling cellular protein phosphatase-1 (PP1), an abundant group of Ser/Thr phosphatases, involves phosphorylation of PP1-specific inhibitor proteins. Malfunctions of these inhibitor proteins have been linked to a variety of diseases, including cardiovascular disease and cancer. Upon phosphorylation at Thr(38), the 17-kDa PP1 inhibitor protein, CPI-17, selectively inhibits a specific form of PP1, myosin light chain phosphatase, which transduces multiple kinase signals into the phosphorylation of myosin II and other proteins. Here, the mechanisms underlying PP1 inhibition and the kinase/PP1 cross-talk mediated by CPI-17 and its related proteins, PHI, KEPI, and GBPI, are discussed.

Clinical And Translational Implications Of The Caveolin Gene Family: Lessons From Mouse Models And Human Genetic Disorders., Isabelle Mercier, Jean-Francois Jasmin, Stephanos Pavlides, Carlo Minetti, Neal Flomenberg, Richard G Pestell, Philippe G Frank, Federica Sotgia, Michael P Lisanti

Department of Stem Cell Biology and Regenerative Medicine Faculty Papers & Presentations

Here we review the clinical and translational implications of the caveolin gene family for understanding the pathogenesis of human diseases, including breast and prostate cancers, pulmonary hypertension, cardiomyopathy, diabetes, and muscular dystrophy. Detailed phenotypic analysis of caveolin knockout mice has served to highlight the crucial role of a caveolin deficiency in the pathogenesis of many human disease processes. Mutations in the human caveolin genes are associated with a number of established genetic disorders (such as breast cancer, lipodystrophy, muscular dystrophy, and cardiomyopathy), making the caveolins important and novel targets for drug development. The implementation of new strategies for caveolin replacement …