Medical Specialties Commons^™

Targeting The Stat5 Pathway In Ph+ Acute Lymphoblastic Leukemia, Valentina Minieri, Marco De Dominici, Marja T. Nevalainen, Bruno Calabretta

Department of Cancer Biology Faculty Papers

No abstract provided.

Emt- And Stroma-Related Gene Expression And Resistance To Pd-1 Blockade In Urothelial Cancer., Li Wang, Abdel Saci, Peter M. Szabo, Scott D. Chasalow, Mireia Castillo-Martin, Josep Domingo-Domenech, Arlene Siefker-Radtke, Padmanee Sharma, John P. Sfakianos, Yixuan Gong, Ana Dominguez-Andres, William K. Oh, David Mulholland, Alex Azrilevich, Liangyuan Hu, Carlos Cordon-Cardo, Hélène Salmon, Nina Bhardwaj, Jun Zhu, Matthew D. Galsky

Department of Cancer Biology Faculty Papers

Cancers infiltrated with T-cells are associated with a higher likelihood of response to PD-1/PD-L1 blockade. Counterintuitively, a correlation between epithelial-mesenchymal transition (EMT)-related gene expression and T-cell infiltration has been observed across tumor types. Here we demonstrate, using The Cancer Genome Atlas (TCGA) urothelial cancer dataset, that although a gene expression-based measure of infiltrating T-cell abundance and EMT-related gene expression are positively correlated, these signatures convey disparate prognostic information. We further demonstrate that non-hematopoietic stromal cells are a major source of EMT-related gene expression in bulk urothelial cancer transcriptomes. Finally, using a cohort of patients with metastatic urothelial cancer treated with …

Semaphorin 5a Drives Melanoma Progression: Role Of Bcl-2, Mir-204 And C-Myb., Simona D'Aguanno, Elisabetta Valentini, Maria Grazia Tupone, Marianna Desideri, Marta Di Martile, Manuela Spagnuolo, Simonetta Buglioni, Cristiana Ercolani, Italia Falcone, Marco De Dominici, Michele Milella, Maria Giulia Rizzo, Bruno Calabretta, Carlo Cota, Andrea Anichini, Daniela Trisciuoglio, Donatella Del Bufalo

Department of Cancer Biology Faculty Papers

BACKGROUND: Melanoma, the most aggressive form of skin cancer, is characterized by high rates of metastasis, drug resistance and mortality. Here we investigated the role of Semaphorin 5A (Sema5A) on the properties associated with melanoma progression and the factors involved in Sema5A regulation.

METHODS: Western blotting, qRT-PCR, Chromatin immunoprecipitation (ChIP) assay, immunohistochemistry of melanoma patient specimens and xenograft tissues, in vitro Transwell assay for cell migration and invasion evaluation, in vitro capillary-like structure formation analysis.

RESULTS: A significant correlation of Sema5A mRNA expression and melanoma progression was observed by analyzing GEO profile dataset. Endogenous Sema5A protein was detected in 95% …

Mir-196b Target Screen Reveals Mechanisms Maintaining Leukemia Stemness With Therapeutic Potential., Sara E. Meyer, David E. Muench, Andrew M. Rogers, Tess J. Newkold, Emily Orr, Eric O'Brien, John P. Perentesis, John G. Doench, Ashish Lal, Patrick J. Morris, Craig J. Thomas, Judy Lieberman, Edwina Mcglinn, Bruce J. Aronow, Nathan Salomonis, H. Leighton Grimes

Department of Cancer Biology Faculty Papers

We have shown that antagomiR inhibition of miRNA miR-21 and miR-196b activity is sufficient to ablate MLL-AF9 leukemia stem cells (LSC) in vivo. Here, we used an shRNA screening approach to mimic miRNA activity on experimentally verified miR-196b targets to identify functionally important and therapeutically relevant pathways downstream of oncogenic miRNA in MLL-r AML. We found Cdkn1b (p27^Kip1) is a direct miR-196b target whose repression enhanced an embryonic stem cell–like signature associated with decreased leukemia latency and increased numbers of leukemia stem cells in vivo. Conversely, elevation of p27^Kip1 significantly reduced MLL-r leukemia self-renewal, promoted monocytic differentiation …

Mapk Reliance Via Acquired Cdk4/6 Inhibitor Resistance In Cancer., Renée De Leeuw, Christopher Mcnair, Matthew J. Schiewer, Neermala Poudel Neupane, Lucas J. Brand, Michael A. Augello, Zhen Li, Larry C. Cheng, Akihiro Yoshida, Sean M. Courtney, E. Starr Hazard, Gary Hardiman, Maha H. Hussain, J. Alan Diehl, Justin M. Drake, William Kevin Kelly, Karen E. Knudsen

Department of Cancer Biology Faculty Papers

Purpose: Loss of cell-cycle control is a hallmark of cancer, which can be targeted with agents, including cyclin-dependent kinase-4/6 (CDK4/6) kinase inhibitors that impinge upon the G₁-S cell-cycle checkpoint via maintaining activity of the retinoblastoma tumor suppressor (RB). This class of drugs is under clinical investigation for various solid tumor types and has recently been FDA-approved for treatment of breast cancer. However, development of therapeutic resistance is not uncommon.

Experimental Design: In this study, palbociclib (a CDK4/6 inhibitor) resistance was established in models of early stage, RB-positive cancer.

Results: This study demonstrates that acquired palbociclib resistance renders cancer …

Syntaphilin Ubiquitination Regulates Mitochondrial Dynamics And Tumor Cell Movements., Jae Ho Seo, Ekta Agarwal, Kelly G. Bryant, M. Cecilia Caino, Eui Tae Kim, Andrew V. Kossenkov, Hsin-Yao Tang, Lucia R. Languino, Dmitry I. Gabrilovich, Andrew R. Cohen, David W. Speicher, Dario C. Altieri

Department of Cancer Biology Faculty Papers

Syntaphilin (SNPH) inhibits the movement of mitochondria in tumor cells, preventing their accumulation at the cortical cytoskeleton and limiting the bioenergetics of cell motility and invasion. Although this may suppress metastasis, the regulation of the SNPH pathway is not well understood. Using a global proteomics screen, we show that SNPH associates with multiple regulators of ubiquitin-dependent responses and is ubiquitinated by the E3 ligase CHIP (or STUB1) on Lys111 and Lys153 in the microtubule-binding domain. SNPH ubiquitination did not result in protein degradation, but instead anchored SNPH on tubulin to inhibit mitochondrial motility and cycles of organelle fusion and fission, …

Concurrent Regulation Of Lkb1 And Camkk2 In The Activation Of Ampk In Castrate-Resistant Prostate Cancer By A Well-Defined Polyherbal Mixture With Anticancer Properties., Amber F. Macdonald, Ahmed Bettaieb, Dallas R. Donohoe, Dina S. Alani, Anna Han, Yi Zhao, Jay Whelan

Department of Cancer Biology Faculty Papers

BACKGROUND: Zyflamend, a blend of herbal extracts, effectively inhibits tumor growth using preclinical models of castrate-resistant prostate cancer mediated in part by 5'-adenosine monophosphate-activated protein kinase (AMPK), a master energy sensor of the cell. Clinically, treatment with Zyflamend and/or metformin (activators of AMPK) had benefits in castrate-resistant prostate cancer patients who no longer responded to treatment. Two predominant upstream kinases are known to activate AMPK: liver kinase B1 (LKB1), a tumor suppressor, and calcium-calmodulin kinase kinase-2 (CaMKK2), a tumor promotor over-expressed in many cancers. The objective was to interrogate how Zyflamend activates AMPK by determining the roles of LKB1 and …

A Preexisting Rare Pik3ca E545k Subpopulation Confers Clinical Resistance To Mek Plus Cdk4/6 Inhibition In Nras Melanoma And Is Dependent On S6k1 Signaling, Gabriele Romano, Pei-Ling Chen, Ping Song, Jennifer L. Mcquade, Roger J. Liang, Mingguang Liu, Whijae Roh, Dzifa Y. Duose, Fernando C.L. Carapeto, Jun Li, Jessica L.F. Teh, Andrew A. Aplin, Merry Chen, Jianhua Zhang, Alexander J. Lazar, Michael A. Davies, P. Andrew Futreal, Rodabe N. Amaria, David Y. Zhang, Jennifer A. Wargo, Lawrence N. Kwong

Department of Cancer Biology Faculty Papers

Combined MEK and CDK4/6 inhibition (MEKi + CDK4i) has shown promising clinical outcomes in patients with NRAS- mutant melanoma. Here, we interrogated longitudinal biopsies from a patient who initially responded to MEKi + CDK4i therapy but subsequently developed resistance. Whole-exome sequencing and functional validation identified an acquired PIK3CA ^E545K mutation as conferring drug resistance. We demonstrate that PIK3CA ^E545K preexisted in a rare subpopulation that was missed by both clinical and research testing, but was revealed upon multiregion sampling due to PIK3CA ^E545K being nonuniformly distributed. This resistant population rapidly expanded after the initiation of MEKi + CDK4i therapy and …

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 …

Targeting Cdk6 And Bcl2 Exploits The "Myb Addiction" Of Ph+ Acute Lymphoblastic Leukemia, Marco De Dominici, Patrizia Porazzi, Angela Rachele Soliera, Samanta A. Mariani, Sankar Addya, Paolo Fortina, Luke F. Peterson, Orietta Spinelli, Alessandro Rambaldi, Giovanni Martinelli, Anna Ferrari, Ilaria Iacobucci, Bruno Calabretta

Department of Cancer Biology Faculty Papers

Philadelphia chromosome–positive acute lymphoblastic leukemia (Ph^þ ALL) is currently treated with BCR-ABL1 tyrosine kinase inhibitors (TKI) in combination with chemotherapy. However, most patients develop resistance to TKI through BCR-ABL1–dependent and –independent mechanisms. Newly developed TKI can target Ph^þ ALL cells with BCR-ABL1–dependent resistance; however, overcoming BCR-ABL1–independent mechanisms of resistance remains challenging because transcription factors, which are difficult to inhibit, are often involved. We show here that (i) the growth of Ph^þ ALL cell lines and primary cells is highly dependent on MYB-mediated transcriptional upregulation of CDK6, cyclin D3, and BCL2, and (ii) restoring their expression in MYB-silenced …

Differential Impact Of Rb Status On E2f1 Reprogramming In Human Cancer., Christopher Mcnair, Kexin Xu, Amy C. Mandigo, Matteo Benelli, Benjamin E. Leiby, Daniel Rodrigues, Johan Lindberg, Henrik Gronberg, Mateus Crespo, Bram De Laere, Luc Dirix, Tapio Visakorpi, Fugen Li, Felix Y. Feng, Johann De Bono, Francesca Demichelis, Mark A. Rubin, Myles Brown, Karen E. Knudsen

Department of Cancer Biology Faculty Papers

The tumor suppressor protein retinoblastoma (RB) is mechanistically linked to suppression of transcription factor E2F1-mediated cell cycle regulation. For multiple tumor types, loss of RB function is associated with poor clinical outcome. RB action is abrogated either by direct depletion or through inactivation of RB function; however, the basis for this selectivity is unknown. Here, analysis of tumor samples and cell-free DNA from patients with advanced prostate cancer showed that direct RB loss was the preferred pathway of disruption in human disease. While RB loss was associated with lethal disease, RB-deficient tumors had no proliferative advantage and exhibited downstream effects …

Erk-Mediated Phosphorylation Regulates Sox10 Sumoylation And Targets Expression In Mutant Braf Melanoma., Shujun Han, Yibo Ren, Wangxiao He, Huadong Liu, Zhe Zhi, Xinliang Zhu, Tielin Yang, Yu Rong, Bohan Ma, Timothy J. Purwin, Zhenlin Ouyang, Caixia Li, Xun Wang, Xueqiang Wang, Huizi Yang, Yan Zheng, Andrew E. Aplin, Jiankang Liu, Yongping Shao

Department of Cancer Biology Faculty Papers

In human mutant BRAF melanoma cells, the stemness transcription factor FOXD3 is rapidly induced by inhibition of ERK1/2 signaling and mediates adaptive resistance to RAF inhibitors. However, the mechanism underlying ERK signaling control of FOXD3 expression remains unknown. Here we show that SOX10 is both necessary and sufficient for RAF inhibitor-induced expression of FOXD3 in mutant BRAF melanoma cells. SOX10 activates the transcription of FOXD3 by binding to a regulatory element in FOXD3 promoter. Phosphorylation of SOX10 by ERK inhibits its transcription activity toward multiple target genes by interfering with the sumoylation of SOX10 at K55, which is essential for …

Response And Resistance To Paradox-Breaking Braf Inhibitor In Melanomas, Edward J. Hartsough, Curtis H. Kugel, Michael J. Vido, Adam C. Berger, Timothy J. Purwin, Allison F. Goldberg, Michael A. Davies, Matthew J. Schiewer, Karen E. Knudsen, Gideon Bollag, Andrew E. Aplin

Department of Cancer Biology Faculty Papers

FDA-approved BRAF inhibitors produce high response rates and improve overall survival in patients with BRAF V600E/K-mutant melanoma, but are linked to pathologies associated with paradoxical ERK1/2 activation in wild-type BRAF cells. To overcome this limitation, a next-generation paradox-breaking RAF inhibitor (PLX8394) has been designed. Here, we show that by using a quantitative reporter assay, PLX8394 rapidly suppressed ERK1/2 reporter activity and growth of mutant BRAF melanoma xenografts. Ex vivo treatment of xenografts and use of a patient-derived explant system (PDeX) revealed that PLX8394 suppressed ERK1/2 signaling and elicited apoptosis more effectively than the FDA-approved BRAF inhibitor, vemurafenib. Furthermore, PLX8394 was …