Medicine and Health Sciences Commons^™

The Nogo Receptor Ngr2, A Novel Αvβ3 Integrin Effector, Induces Neuroendocrine Differentiation In Prostate Cancer, Fabio Quaglia, Shiv Ram Krishn, Khalid Sossey-Alaoui, Priyanka Shailendra Rana, Elzbieta Pluskota, Pyung Hun Park, Christopher D. Shields, Stephen Lin, Peter Mccue, Andrew V. Kossenkov, Yanqing Wang, David W. Goodrich, Sheng-Yu Ku, Himisha Beltran, William K. Kelly, Eva Corey, Maja Klose, Christine Bandtlow, Qin Liu, Dario C. Altieri, Edward F. Plow, Lucia R. Languino

Department of Cancer Biology Faculty Papers

Androgen deprivation therapies aimed to target prostate cancer (PrCa) are only partially successful given the occurrence of neuroendocrine PrCa (NEPrCa), a highly aggressive and highly metastatic form of PrCa, for which there is no effective therapeutic approach. Our group has demonstrated that while absent in prostate adenocarcinoma, the αVβ3 integrin expression is increased during PrCa progression toward NEPrCa. Here, we show a novel pathway activated by αVβ3 that promotes NE differentiation (NED). This novel pathway requires the expression of a GPI-linked surface molecule, NgR2, also known as Nogo-66 receptor homolog 1. We show here that NgR2 is upregulated by αVβ3, …

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-Mediated Microrna Expression Signature Predicts Breast Cancer Outcome, Guangxue Wang, Michael Gormley, Jing Qiao, Qian Zhao, Min Wang, Gabriele Disante, Shengqiong Deng, Lin Dong, Timothy G. Pestell, Xiaoming Ju, Mathew C. Casimiro, Sankar Addya, Adam Ertel, Ayden Tozeren, Qinchuan Li, Zuoren Yu, Richard G. Pestell

Department of Cancer Biology Faculty Papers

Background: Genetic classification of breast cancer based on the coding mRNA suggests the evolution of distinct subtypes. Whether the non-coding genome is altered concordantly with the coding genome and the mechanism by which the cell cycle directly controls the non-coding genome is poorly understood.

Methods: Herein, the miRNA signature maintained by endogenous cyclin D1 in human breast cancer cells was defined. In order to determine the clinical significance of the cyclin D1-mediated miRNA signature, we defined a miRNA expression superset from 459 breast cancer samples. We compared the coding and non-coding genome of breast cancer subtypes.

Results: Hierarchical clustering of …

Non-Hodgkin And Hodgkin Lymphomas Select For Overexpression Of Bclw., Clare M. Adams, Ramkrishna Mitra, Jerald Z. Gong, Md, Christine M. Eischen

Department of Cancer Biology Faculty Papers

Purpose: B-cell lymphomas must acquire resistance to apoptosis during their development. We recently discovered BCLW, an antiapoptotic BCL2 family member thought only to contribute to spermatogenesis, was overexpressed in diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma. To gain insight into the contribution of BCLW to B-cell lymphomas and its potential to confer resistance to BCL2 inhibitors, we investigated the expression of BCLW and the other antiapoptotic BCL2 family members in six different B-cell lymphomas. Experimental Design: We performed a large-scale gene expression analysis of datasets comprising approximately 2,300 lymphoma patient samples, including non-Hodgkin and Hodgkin lymphomas as well as …

Detection Of Activating Estrogen Receptor Gene (Esr1) Mutations In Single Circulating Tumor Cells, Carmela Paolillo, Zhaomei Mu, Giovanna Rossi, Matthew J. Schiewer, Thomas Nguyen, Laura Austin, Ettore Capoluongo, Karen E. Knudsen, Massimo Cristofanilli, Paolo Fortina

Department of Cancer Biology Faculty Papers

Purpose: Early detection is essential for treatment plans before onset of metastatic disease. Our purpose was to demonstrate feasibility to detect and monitor estrogen receptor 1 (ESR1) gene mutations at the single circulating tumor cell (CTC) level in metastatic breast cancer (MBC). Experimental Design: We used a CTC molecular characterization approach to investigate heterogeneity of 14 hotspot mutations in ESR1 and their correlation with endocrine resistance. Combining the CellSearch and DEPArray technologies allowed recovery of 71 single CTCs and 12 WBC from 3 ER-positive MBC patients. Forty CTCs and 12 WBC were subjected to whole genome amplification by MALBAC and …

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 …

Inhibition Of Age-Related Therapy Resistance In Melanoma By Rosiglitazone-Mediated Induction Of Klotho., Reeti Behera, Amanpreet Kaur, Marie R. Webster, Suyeon Kim, Abibatou Ndoye, Curtis H. Kugel, Gretchen M. Alicea, Joshua Wang, Kanad Ghosh, Phil Cheng, Sofia Lisanti, Katie Marchbank, Vanessa Dang, Mitchell Levesque, Reinhard Dummer, Xiaowei Xu, Meenhard Herlyn, Andrew E. Aplin, Alexander Roesch, Cecilia Caino, Dario C. Altieri, Ashani T. Weeraratna

Department of Cancer Biology Faculty Papers

Purpose: Aging is a poor prognostic factor for melanoma. We have shown that melanoma cells in an aged microenvironment are more resistant to targeted therapy than identical cells in a young microenvironment. This is dependent on age-related secreted factors. Klotho is an age-related protein whose serum levels decrease dramatically by age 40. Most studies on klotho in cancer have focused on the expression of klotho in the tumor cell. We have shown that exogenous klotho inhibits internalization and signaling of Wnt5A, which drives melanoma metastasis and resistance to targeted therapy. We investigate here whether increasing klotho in the aged microenvironment …

Sigma1 Targeting To Suppress Aberrant Androgen Receptor Signaling In Prostate Cancer., Jeffrey D. Thomas, Charles G. Longen, Halley M. Oyer, Nan Chen, Christina M. Maher, Joseph M. Salvino, Blase Kania, Kelsey N. Anderson, William F. Ostrander, Karen E. Knudsen, Felix J. Kim

Department of Cancer Biology Faculty Papers

Suppression of androgen receptor (AR) activity in prostate cancer by androgen depletion or direct AR antagonist treatment, although initially effective, leads to incurable castration-resistant prostate cancer (CRPC) via compensatory mechanisms including resurgence of AR and AR splice variant (ARV) signaling. Emerging evidence suggests that Sigma1 (also known as sigma-1 receptor) is a unique chaperone or scaffolding protein that contributes to cellular protein homeostasis. We reported previously that some Sigma1-selective small molecules can be used to pharmacologically modulate protein homeostasis pathways. We hypothesized that these Sigma1-mediated responses could be exploited to suppress AR protein levels and activity. Here we demonstrate that …

Not So Fast: Cultivating Mirs As Kinks In The Chain Of The Cell Cycle., Matthew J. Schiewer, Karen E. Knudsen

Department of Cancer Biology Faculty Papers

In this issue of Cancer Cell, Hydbring and colleagues define a novel class of microRNAs (miRNAs), deemed "cell-cycle-targeting miRNAs," that target several cyclins/CDKs, reduce tumor cell growth, and induce apoptosis. These miRNAs effectively suppressed chemoresistant patient-derived xenograft growth in vivo, and efficacy could be prospectively predicted with an expression-based algorithm.

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 …

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.

Erbb3-Erbb2 Complexes As A Therapeutic Target In A Subset Of Wild-Type Braf/Nras Cutaneous Melanomas., Claudia Capparelli, Sheera Rosenbaum, Lisa D. Berman-Booty, Amel Salhi, Nadège Gaborit, Tingting Zhan, Inna Chervoneva, Jason Roszik, Scott E. Woodman, Michael A. Davies, Yulius Y. Setiady, Iman Osman, Yosef Yarden, Andrew E. Aplin

Department of Cancer Biology Faculty Papers

The treatment options remain limited for patients with melanoma who are wild-type for both BRAF and NRAS (WT/WT). We demonstrate that a subgroup of WT/WT melanomas display high basal phosphorylation of ErbB3 that is associated with autocrine production of the ErbB3 ligand neuregulin-1 (NRG1). In WT/WT melanoma cells displaying high levels of phospho-ErbB3, knockdown of NRG1 reduced cell viability and was associated with decreased phosphorylation of ErbB3, its coreceptor ErbB2, and its downstream target, AKT. Similar effects were observed by targeting ErbB3 with either siRNAs or the neutralizing ErbB3 monoclonal antibodies huHER3-8 and NG33. In addition, pertuzumab-mediated inhibition of ErbB2 …

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 …

Expression Of The Il-11 Gene In Metastatic Cells Is Supported By Runx2-Smad And Runx2-Cjun Complexes Induced By Tgfβ1., Xuhui Zhang, Hai Wu, Jason R. Dobson, Gillian Browne, Deli Hong, Jacqueline Akech, Lucia R. Languino, Gary S. Stein, Jane B. Lian

Department of Cancer Biology Faculty Papers

In tumor cells, two factors are abnormally increased that contribute to metastatic bone disease: Runx2, a transcription factor that promotes expression of metastasis related and osteolytic genes; and IL-11, a secreted osteolytic cytokine. Here, we addressed a compelling question: Does Runx2 regulate IL-11 gene expression? We find a positive correlation between Runx2, IL-11 and TGFβ1, a driver of the vicious cycle of metastatic bone disease, in prostate cancer (PC) cell lines representing early (LNCaP) and late (PC3) stage disease. Further, like Runx2 knockdown, IL-11 knockdown significantly reduced expression of several osteolytic factors. Modulation of Runx2 expression results in corresponding changes …

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 …

Paracrine Effect Of Nrg1 And Hgf Drives Resistance To Mek Inhibitors In Metastatic Uveal Melanoma., Hanyin Cheng, Mizue Terai, Ken Kageyama, Shinji Ozaki, Peter Mccue, Takami Sato, Andrew E. Aplin

Department of Cancer Biology Faculty Papers

Uveal melanoma patients with metastatic disease usually die within one year, emphasizing an urgent need to develop new treatment strategies for this cancer. MEK inhibitors improve survival in cutaneous melanoma patients but show only modest efficacy in metastatic uveal melanoma patients. In this study, we screened for growth factors that elicited resistance in newly characterized metastatic uveal melanoma cell lines to clinical-grade MEK inhibitors, trametinib and selumetinib. We show that neuregulin 1 (NRG1) and hepatocyte growth factor (HGF) provide resistance to MEK inhibition. Mechanistically, trametinib enhances the responsiveness to NRG1 and sustained HGF-mediated activation of AKT. Individually targeting ERBB3 and …

Chromatin To Clinic: The Molecular Rationale For Parp1 Inhibitor Function., Felix Y. Feng, Johann S. De Bono, Mark A. Rubin, Karen E Knudsen

Department of Cancer Biology Faculty Papers

Poly(ADP-ribose) polymerase 1 (PARP1) inhibitors were recently shown to have potential clinical impact in a number of disease settings, particularly as related to cancer therapy, treatment for cardiovascular dysfunction, and suppression of inflammation. The molecular basis for PARP1 inhibitor function is complex, and appears to depend on the dual roles of PARP1 in DNA damage repair and transcriptional regulation. Here, the mechanisms by which PARP-1 inhibitors elicit clinical response are discussed, and strategies for translating the preclinical elucidation of PARP-1 function into advances in disease management are reviewed.

The Endogenous Cell-Fate Factor Dachshund Restrains Prostate Epithelial Cell Migration Via Repression Of Cytokine Secretion Via A Cxcl Signaling Module., Ke Chen, Kongming Wu, Xuanmao Jiao, Liping Wang, Xiaoming Ju, Min Wang, Gabriele Disante, Shaohua Xu, Qiong Wang, Kevin Li, Xin Sun, Chongwen Xu, Zhiping Li, Mathew C. Casimiro, Adam Ertel, Sankar Addya, Peter Mccue, Michael P. Lisanti, Chenguang Wang, Richard J. Davis, Graeme Mardon, Richard Pestell

Department of Cancer Biology Faculty Papers

Prostate cancer is the second leading form of cancer-related death in men. In a subset of prostate cancer patients, increased chemokine signaling IL8 and IL6 correlates with castrate-resistant prostate cancer (CRPC). IL8 and IL6 are produced by prostate epithelial cells and promote prostate cancer cell invasion; however, the mechanisms restraining prostate epithelial cell cytokine secretion are poorly understood. Herein, the cell-fate determinant factor DACH1 inhibited CRPC tumor growth in mice. Using Dach1(fl/fl)/Probasin-Cre bitransgenic mice, we show IL8 and IL6 secretion was altered by approximately 1,000-fold by endogenous Dach1. Endogenous Dach1 is shown to serve as a key endogenous restraint to …

Novel Actions Of Next-Generation Taxanes Benefit Advanced Stages Of Prostate Cancer., Renée De Leeuw, Lisa D. Berman-Booty, Matthew J. Schiewer, Stephen J Ciment, Robert Den, Adam P. Dicker, William Kelly, Edouard J. Trabulsi, Costas D. Lallas, Leonard G. Gomella, Karen E. Knudsen

Department of Cancer Biology Faculty Papers

PURPOSE: To improve the outcomes of patients with castration-resistant prostate cancer (CRPC), there is an urgent need for more effective therapies and approaches that individualize specific treatments for patients with CRPC. These studies compared the novel taxane cabazitaxel with the previous generation docetaxel, and aimed to determine which tumors are most likely to respond.

EXPERIMENTAL DESIGN: Cabazitaxel and docetaxel were compared via in vitro modeling to determine the molecular mechanism, biochemical and cell biologic impact, and cell proliferation, which was further assessed ex vivo in human tumor explants. Isogenic pairs of RB knockdown and control cells were interrogated in vitro …

The Long Non-Coding Rna Pcat-1 Promotes Prostate Cancer Cell Proliferation Through Cmyc., John R. Prensner, Wei Chen, Sumin Han, Matthew K. Iyer, Qi Cao, Vishal Kothari, Joseph R. Evans, Karen E. Knudsen, Michelle T. Paulsen, Mats Ljungman, Theodore S. Lawrence, Arul M. Chinnaiyan, Felix Y. Feng

Department of Cancer Biology Faculty Papers

Long non-coding RNAs (lncRNAs) represent an emerging layer of cancer biology, contributing to tumor proliferation, invasion, and metastasis. Here, we describe a role for the oncogenic lncRNA PCAT-1 in prostate cancer proliferation through cMyc. We find that PCAT-1-mediated proliferation is dependent on cMyc protein stabilization, and using expression profiling, we observed that cMyc is required for a subset of PCAT-1-induced expression changes. The PCAT-1-cMyc relationship is mediated through the post-transcriptional activity of the MYC 3' untranslated region, and we characterize a role for PCAT-1 in the disruption of MYC-targeting microRNAs. To further elucidate a role for post-transcriptional regulation, we demonstrate …

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 …

A Statement On Vemurafenib-Resistant Melanoma., Edward J Hartsough, A E Aplin

Department of Cancer Biology Faculty Papers

Despite recent advancements in the treatment of late-stage mutant BRAF (V600E/K) melanomas, a major hurdle continues to be acquired resistance to BRAF inhibitors such as vemurafenib. The mechanisms for resistance have proven to be heterogeneous, emphasizing the need to use broad therapeutic approaches. In this issue, the study "Stat3-targeted therapies overcome the acquired resistance to vemurafenib in melanomas" by Liu et al. proposes that signal transducer and activator of transcription 3 (STAT3)-paired box 3 (PAX3) signaling may be a mechanism that is used by melanomas to resist RAF inhibitors.

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 …

Small Non-Coding Rnas Govern Mammary Gland Tumorigenesis., Zuoren Yu, Richard Pestell

Department of Cancer Biology Faculty Papers

Small non-coding RNAs include siRNA, miRNA, piRNA and snoRNA. The involvement of miRNAs in the regulation of mammary gland tumorigenesis has been widely studied while the role for other small non-coding RNAs remains unclear. Here we summarize the involvement of miRNA in breast cancer onset and progression through regulating the cell cycle and cellular proliferation. The regulation of breast cancer stem cells and tumor regeneration by miRNA is reviewed. In addition, the emerging evidence demonstrating the involvement of piRNA and snoRNA in breast cancer is briefly described.

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 …