Cancer Biology Commons^™

P300/Cbp Inhibition With Inobrodib In Combination With Gilteritinib And Venetoclax Targets Leukemia Stem Cells In Epigenetic Mutant Aml, Melanie L. Goetz, Jennifer S. Romer-Seibert, Amanda M. Versace, Scott Kogan, Chetan Jeurkar, Robert L. Bowman, Nigel Brooks, Kris Frese, Sara E. Meyer

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Acute myeloid leukemia (AML) is a fatal blood cancer with cytotoxic chemotherapy offering at best 25% 5-year survival. While targeted BCL2 and FLT3 inhibitors venetoclax and gilteritinib are used upfront in the treatment of a subset of adult patients with AML and help to extend the survival of some patients, a curative treatment combination with minimal side effects has yet to be discovered. We find that use of the dual histone acetyltransferase p300/CBP bromodomain inhibitor CCS1477 (inobrodib), together with venetoclax and gilteritinib, virtually eliminates leukemia stem cells in an aggressive preclinical model of DNMT3A/FLT3-mutant AML by impairing pro-oncogenic survival and …

Diacylglycerol Kinase Eta As A Novel Target In Nras Mutant Melanoma, Haley P. Wilson, Casey D. Stefanski, Signe Caksa, Glenn L. Mersky, Scott D. Varney, Jelan I. Haj, Dan A. Erkes, Timothy J. Purwin, Vivian Chua, Andrew E. Aplin

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

NRAS mutations occur in 10%-30% of cutaneous melanomas and are associated with high tumor mutational burden. Mutant NRAS signaling drives aberrant cell growth and proliferation, in part, through activation of the RAF-MEK-ERK1/2 kinase pathway; however, targeted therapies to this pathway have limited effectiveness in patients with NRAS mutant melanoma. The role of other targetable signaling pathways in NRAS mutant melanoma is poorly characterized. Here, we demonstrated that one isoform of diacylglycerol kinase, diacylglycerol kinase eta (DGKη), a lipid signaling regulator, was highly expressed in NRAS mutant melanoma patient samples. Knockdown of DGKH in NRAS mutant melanoma cell lines resulted in …

Synthetic Lethality Between Rb-Loss And E2f3 Inhibition In Small Cell Cancers Targeted By Pyrimidine Synthesis Blockade, Evan R. Abt, Liang Wang, Grigor Varuzhanyan, Jack Freeland, Tian He, Guadalupe M. Peña-Garcia, Lauryn Ruegg, Jami Mclaughlin, Donghui Cheng, Nikolas G. Balanis, Chia-Chun Chen, Yang Xu, Yi Xing, Sanaz Memarzadeh, Caius G. Radu, Thomas G. Graeber, Owen N. Witte

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Small cell carcinoma is a highly lethal cancer variant often found with neuroendocrine (NE) features, as exemplified by small cell lung cancer and small cell NE prostate cancer (SCPC). A genome-wide CRISPR dependency screen using SCPC models generated through human prostate cell transformation identifies a requirement for the transcription factor E2F3. E2F3 dependency is linked to RB inactivation, a near universal occurrence across small cell cancers. The requirement for E2F3 is shared by RB-deficient cells originating from the prostate, lung, and adnexa. In RB-deficient cancer cells, E2F3 inhibition restrains cell cycle progression, proliferation, and tumor growth in vivo. Inhibition of …

Runx2 Cooperates With Srebp1 To Rewire Cancer Metabolism And Promote Aggressiveness, Emanuele Vitale, Mila Gugnoni, Veronica Manicardi, Silvia Muccioli, Federica Torricelli, Benedetta Donati, Simonetta Piana, Gloria Manzotti, Elisa Salviato, Francesca Reggiani, Cristian Ascione, Rebecca Vezzani, Moira Ragazzi, Mattia Forcato, Oriana Romano, Silvio Bicciato, Aaron Goldman, Marco Tigano, Alessia Ciarrocchi

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Embryonic Transcription Factors (TFs) are often reactivated in cancer, driving developmental gene programs that support phenotypic plasticity. Metabolic adaptation fuels this plasticity by supplying energy and molecular building blocks for growth. RUNX2, the master regulator of bone morphogenesis, is ectopically expressed in epithelial cancer, promoting metastasis through trans-differentiation processes like Epithelial-to-Mesenchymal Transition (EMT) and osteomimicry. By combining omics data with functional validation, we demonstrated that RUNX2 drives cancer cell metabolic rewiring by repressing mitochondrial respiration while promoting anabolic processes. We showed that RUNX2 upregulates key genes of lipid biosynthesis by regulating and cooperating with SREBP1. In vivo expression analysis in …

Setdb1 Is Critically Required For Uveal Melanoma Growth And Represents A Promising Therapeutic Target, Imène Krossa, Céline Pisibon, Yann Cheli, Karine Bille, Mélanie Dalmasso, Sabah Hamadat, Chrystel Husser, Marie Irondelle, Julien Cherfils-Vicini, Frédéric Soysouvanh, Sacha Nahon-Esteve, Arnaud Martel, Sandra Lassalle, Jean-Pierre Caujolle, Célia Maschi, Stéphanie Baillif, Dan Hasson, Saul Carcamo, Andrerw E. Aplin, Irwin Davidson, Emily Bernstein, Valeria Naim, Robert Ballotti, Corine Bertolotto, Thomas Strub

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Metastatic uveal melanomas are highly resistant to all existing treatments. To identify actionable vulnerabilities, we conducted a CRISPR-Cas9 knockout screen using a library composed of chromatin regulators. We revealed that the lysine methyltransferase, SETDB1, plays a critical role in metastatic uveal melanoma cell proliferation and survival. Functionally, SETDB1 deficiency induces a DNA damage response, senescence-like state and growth arrest. Knockdown of SETDB1 is associated with a decreased expression of genes related to replication and cell cycle. Moreover, deficiency in CDC6, an essential regulator of DNA replication, phenocopies SETDB1 inhibition. Using a pre-clinical model, we further demonstrated that anti-SETDB1 therapy impairs …

A Novel Sialylation Pathway Mediated By Extracellular Vesicles In Aggressive Prostate Cancer, Camila A. Bach, Md Niamat Hossain, Ishan J. Chaudhari, Cecilia E. Verrillo, Nicole M. Naranjo, Isabella Amoroso, Anna Testa, Samuel Sey, W. Kevin Kelly, Susan L. Bellis, Aurelio Lorico, Ada G. Blidner, Gabriel A. Rabinovich, Lucia R. Languino

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Altered cell surface glycosylation is a hallmark of cancer; among aberrant glycan structures, hypersialylated proteins contribute to disease progression. The enzyme ST6 β-galactoside α2,6-sialyltransferase 1 (ST6GAL1) mediates α2,6-linked sialylation of N-glycosylated proteins and is upregulated in many cancers, including prostate cancer (PrCa). We propose that ST6GAL1 may be released by cancer cells in small extracellular vesicles (sEVs) in the PrCa tumor microenvironment to potentially modulate cell surface sialylation in recipient cells. We isolated sEVs from PrCa cells by density gradient separation and characterized them by nanoparticle tracking analysis using ZetaView and immunoblotting analysis. We identified ST6GAL1 in both its membrane-bound …

Elevated Nr2f1 Underlies The Persistence Of Invasive Disease After Treatment Of Braf-Mutant Melanoma, Manoela Tiago, Timothy J. Purwin, Casey D. Stefanski, Renaira Oliveira Da Silva, Mitchell E. Fane, Yash Chhabra, Jelan I. Haj, Jessica L. F. Teh, Rama Kadamb, Weijia Cai, Sheera Rosenbaum, Vivian Chua, Nir Hacohen, Michael A. Davies, Jessie Villanueva, Inna Chervoneva, Ashani T. Weeraratna, Dan A. Erkes, Claudia Capparelli, Julio A. Aguirre-Ghiso, Andrew E. Aplin

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Despite the success of targeted inhibitors in cutaneous melanoma, therapeutic responses are limited by the aged tumor microenvironment and drug-tolerant residual cells. Given the similarities between drug tolerance and cellular dormancy, we studied the dormancy marker, nuclear receptor subfamily 2 group F member 1 (NR2F1), in response to BRAF-V600E inhibitors (BRAFi) plus MEK inhibitors (MEKi) in BRAF-mutant melanoma models. Transcriptomic analysis of melanoma patient samples treated with BRAFi + MEKi showed increased NR2F1. NR2F1 was highly expressed in the drug-tolerant invasive cell state of minimal residual disease in patient-derived and mouse-derived xenografts on BRAFi + MEKi. NR2F1 over-expression was sufficient …

Irradiation Of Prostate Cancer Alters Circulating Small Extracellular Vesicle Functions, Aejaz Sayeed, Vaughn Garcia, Cecilia E. Verrillo, Rachel M. Derita, Md Niamat Hossain, Shiv R. Krishn, Samuel Sey, Christopher D. Shields, Adrian D. Altieri, Qin Liu, Khalid Sossey-Alaoui, William K. Kelly, Lucia R. Languino

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

It is known that β1 integrins and a downstream signaling molecule c-Src are upregulated in prostate cancer (PrCa) tissues, are co-expressed in circulating small extracellular vesicles (sEVs) and contribute to cancer progression. Here, we demonstrate that sEVs from PrCa patients show robust expression of both β1 integrins and c-Src. The impact of irradiation, a widely used therapy for the treatment of PrCa, on circulating sEVs is however not fully understood. We show that sEVs isolated from the plasma of transgenic adenocarcinoma of mouse prostate (TRAMP) mice, stimulate migration and anchorage-independent growth of recipient cancer cells, but sEVs are not active …

Targeting Bard1 Suppresses A Myc-Dependent Transcriptional Program And Tumor Growth In Pancreatic Ductal Adenocarcinoma, Sohum Patel, Eleanor Jenkins, Rutuj P. Kusurkar, Sherry Lee, Wei Jiang, Avinoam Nevler, Matthew Mccoy, Michael J. Pishvaian, Rosalie C. Sears, Jonathan R. Brody, Charles J. Yeo, Aditi Jain

Department of Surgery Faculty Papers

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers demanding better and more effective therapies. BARD1 or BRCA1-Associated -Ring Domain-1 plays a pivotal role in homologous recombination repair (HRR). However, its function and the underlying molecular mechanisms in PDAC are still not fully elucidated. Here, we demonstrate that BARD1 is overexpressed in PDAC and its genetic inhibition suppresses c-Myc and disrupts c-Myc dependent transcriptional program. Mechanistically, BARD1 stabilizes c-Myc through ubiquitin-proteasome system by regulating FBXW7. Importantly, targeting BARD1 using either siRNAs or CRISPR/Cas9 deletion blocks PDAC growth in vitro and in vivo, without any signs of toxicity to mice. …

Sigma1 Inhibitor Suppression Of Adaptive Immune Resistance Mechanisms Mediated By Cancer Cell Derived Extracellular Vesicles, Paola A. Castagnino, Derick A. Haas, Luca Musante, Nathalia A. Tancler, Bach V. Tran, Rhonda Kean, Alexandra R. Steck, Luis A. Martinez, Elahe A. Mostaghel, D. Craig Hooper, Felix J. Kim

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Adaptive immune resistance in cancer describes the various mechanisms by which tumors adapt to evade anti-tumor immune responses. IFN-γ induction of programmed death-ligand 1 (PD-L1) was the first defined and validated adaptive immune resistance mechanism. The endoplasmic reticulum (ER) is central to adaptive immune resistance as immune modulatory secreted and integral membrane proteins are dependent on ER. Sigma1 is a unique ligand-regulated integral membrane scaffolding protein enriched in the ER of cancer cells. PD-L1 is an integral membrane glycoprotein that is translated into the ER and processed through the cellular secretory pathway. At the cell surface, PD-L1 is an immune …

Role Of Kindlin 2 In Prostate Cancer, Katarzyna Bialkowska, Lamyae El Khalki, Priyanka Rana, Wei Wang, Daniel Lindner, Yvonne Parker, Lucia Languino, Dario Altieri, Elzbieta Pluskota, Khalid Sossey-Alaoui, Edward Plow

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Kindlin-2 is a cytoskeletal adapter protein that is present in many different cell types. By virtue of its interaction with multiple binding partners, Kindlin-2 intercalates into numerous signaling pathways and cytoskeletal nodes. A specific interaction of Kindlin-2 that is of paramount importance in many cellular responses is its direct binding to the cytoplasmic tails of integrins, an interaction that controls many of the adhesive, migratory and signaling responses mediated by members of the integrin family of cell-surface heterodimers. Kindlin-2 is highly expressed in many cancers and is particularly prominent in prostate cancer cells. CRISPR/cas9 was used as a primary approach …

Stanniocalcin 2 Governs Cancer Cell Adaptation To Nutrient Insufficiency Through Alleviation Of Oxidative Stress, Shuo Qie, Haijuan Xiong, Yaqi Liu, Chenhui Yan, Yalei Wang, Lifeng Tian, Chenguang Wang, Nianli Sang

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Solid tumours often endure nutrient insufficiency during progression. How tumour cells adapt to temporal and spatial nutrient insufficiency remains unclear. We previously identified STC2 as one of the most upregulated genes in cells exposed to nutrient insufficiency by transcriptome screening, indicating the potential of STC2 in cellular adaptation to nutrient insufficiency. However, the molecular mechanisms underlying STC2 induction by nutrient insufficiency and subsequent adaptation remain elusive. Here, we report that STC2 protein is dramatically increased and secreted into the culture media by Gln-/Glc- deprivation. STC2 promoter contains cis-elements that are activated by ATF4 and p65/RelA, two transcription factors activated by …

Expression Of The Αvβ3 Integrin Affects Prostate Cancer Sev Cargo And Density And Promotes Sev Pro-Tumorigenic Activity In Vivo Through A Gpi-Anchored Receptor, Ngr2, Cecilia Verrillo, Fabio Quaglia, Christopher Shields, Stephen Lin, Andrew Kossenkov, Hsin-Yao Tang, David Speicher, Nicole Naranjo, Anna Testa, William Kelly, Qin Liu, Benjamin Leiby, Luca Musante, Khalid Sossey-Alaoui, Navneet Dogra, Tzu-Yi Chen, Dario Altieri, Lucia Languino

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

It is known that small extracellular vesicles (sEVs) are released from cancer cells and contribute to cancer progression via crosstalk with recipient cells. We have previously reported that sEVs expressing the αVβ3 integrin, a protein upregulated in aggressive neuroendocrine prostate cancer (NEPrCa), contribute to neuroendocrine differentiation (NED) in recipient cells. Here, we examine the impact of αVβ3 expression on sEV protein content, density and function. sEVs used in this study were isolated by iodixanol density gradients and characterized by nanoparticle tracking analysis, immunoblotting and single vesicle analysis. Our proteomic profile of sEVs containing αVβ3 shows downregulation of typical effectors involved …

The Janus Kinase 1 Is Critical For Pancreatic Cancer Initiation And Progression, Hridaya Shrestha, Patrick Rädler, Rayane Dennaoui, Madison Wicker, Nirakar Rajbhandari, Yunguang Sun, Amy Peck, Kerry Vistisen, Aleata Triplett, Rafic Beydoun, Esta Sterneck, Dieter Saur, Hallgeir Rui, Kay-Uwe Wagner

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Interleukin-6 (IL-6)-class inflammatory cytokines signal through the Janus tyrosine kinase (JAK)/signal transducer and activator of transcription (STAT) pathway and promote the development of pancreatic ductal adenocarcinoma (PDAC); however, the functions of specific intracellular signaling mediators in this process are less well defined. Using a ligand-controlled and pancreas-specific knockout in adult mice, we demonstrate in this study that JAK1 deficiency prevents the formation of KRAS^G12D-induced pancreatic tumors, and we establish that JAK1 is essential for the constitutive activation of STAT3, whose activation is a prominent characteristic of PDAC. We identify CCAAT/enhancer binding protein δ (C/EBPδ) as a biologically relevant …

Decorin Suppresses Tumor Lymphangiogenesis: A Mechanism To Curtail Cancer Progression, Dipon K. Mondal, Christopher Xie, Gabriel J. Pascal, Simone Buraschi, Renato V. Iozzo

Kimmel Cancer Center Faculty Papers

The complex interplay between malignant cells and the cellular and molecular components of the tumor stroma is a key aspect of cancer growth and development. These tumor-host interactions are often affected by soluble bioactive molecules such as proteoglycans. Decorin, an archetypical small leucine-rich proteoglycan primarily expressed by stromal cells, affects cancer growth in its soluble form by interacting with several receptor tyrosine kinases (RTK). Overall, decorin leads to a context-dependent and protracted cessation of oncogenic RTK activity by attenuating their ability to drive a prosurvival program and to sustain a proangiogenic network. Through an unbiased transcriptomic analysis using deep RNAseq, …

Needle Biopsy Accelerates Pro-Metastatic Changes And Systemic Dissemination In Breast Cancer: Implications For Mortality By Surgery Delay, Hiroyasu Kameyama, Priya Dondapati, Reese Simmons, Macall Leslie, John Langenheim, Yunguang Sun, Misung Yi, Aubrey Rottschaefer, Rashmi Pathak, Shreya Nuguri, Kar-Ming Fung, Shirng-Wern Tsaih, Inna Chervoneva, Hallgeir Rui, Takemi Tanaka

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

ncreased breast cancer (BC) mortality risk posed by delayed surgical resection of tumor after diagnosis is a growing concern, yet the underlying mechanisms remain unknown. Our cohort analyses of early-stage BC patients reveal the emergence of a significantly rising mortality risk when the biopsy-to-surgery interval was extended beyond 53 days. Additionally, histology of post-biopsy tumors shows prolonged retention of a metastasis-permissive wound stroma dominated by M2-like macrophages capable of promoting cancer cell epithelial-to-mesenchymal transition and angiogenesis. We show that needle biopsy promotes systemic dissemination of cancer cells through a mechanism of sustained activation of the COX-2/PGE₂/EP2 feedforward loop, …

Kinome Profiling Identifies Mark3 And Stk10 As Potential Therapeutic Targets In Uveal Melanoma, Usman Baqai, Alison M. Kurimchak, Isabella Trachtenberg, Timothy J. Purwin, Jelan I. Haj, Anna Han, Kristine Luo, Nikole Fandino Pachon, Angela Jeon, Vivian Chua, Michael A. Davies, J Silvio Gutkind, Jeffrey L. Benovic, James S. Duncan, Andrew E. Aplin

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Most uveal melanoma cases harbor activating mutations in either GNAQ or GNA11. Despite activation of the mitogen-activated protein kinase (MAPK) signaling pathway downstream of Gαq/11, there are no effective targeted kinase therapies for metastatic uveal melanoma. The human genome encodes numerous understudied kinases, also called the "dark kinome". Identifying additional kinases regulated by Gαq/11 may uncover novel therapeutic targets for uveal melanoma. In this study, we treated GNAQ-mutant uveal melanoma cell lines with a Gαq/11 inhibitor, YM-254890, and conducted a kinase signaling proteomic screen using multiplexed-kinase inhibitors followed by mass spectrometry. We observed downregulated expression and/or activity of 22 kinases. …

Zinc Treatment Reverses And Anti-Zn-Regulated Mirs Suppress Esophageal Carcinomas In Vivo, Louise Fong, Kay Huebner, Ruiyan Jing, Karl Smalley, Christopher R Brydges, Oliver Fiehn, John Farber, Carlo M Croce

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Esophageal squamous cell carcinoma (ESCC) is a deadly disease with few prevention or treatment options. ESCC development in humans and rodents is associated with Zn deficiency (ZD), inflammation, and overexpression of oncogenic microRNAs: miR-31 and miR-21. In a ZD-promoted ESCC rat model with upregulation of these miRs, systemic antimiR-31 suppresses the miR-31-EGLN3/STK40-NF-κB-controlled inflammatory pathway and ESCC. In this model, systemic delivery of Zn-regulated antimiR-31, followed by antimiR-21, restored expression of tumor-suppressor proteins targeted by these specific miRs: STK40/EGLN3 (miR-31), PDCD4 (miR-21), suppressing inflammation, promoting apoptosis, and inhibiting ESCC development. Moreover, ESCC-bearing Zn-deficient (ZD) rats receiving Zn medication showed a 47% …

The Circadian Cryptochrome, Cry1, Is A Pro-Tumorigenic Factor That Rhythmically Modulates Dna Repair., Ayesha A Shafi, Chris M Mcnair, Jennifer J Mccann, Mohammed Alshalalfa, Anton Shostak, Tesa M Severson, Yanyun Zhu, Andre Bergman, Nicolas Gordon, Amy C Mandigo, Saswati N Chand, Peter Gallagher, Emanuela Dylgjeri, Talya S Laufer, Irina A Vasilevskaya, Matthew J Schiewer, Michael Brunner, Felix Y Feng, Wilbert Zwart, Karen E Knudsen

Department of Cancer Biology Faculty Papers

Mechanisms regulating DNA repair processes remain incompletely defined. Here, the circadian factor CRY1, an evolutionally conserved transcriptional coregulator, is identified as a tumor specific regulator of DNA repair. Key findings demonstrate that CRY1 expression is androgen-responsive and associates with poor outcome in prostate cancer. Functional studies and first-in-field mapping of the CRY1 cistrome and transcriptome reveal that CRY1 regulates DNA repair and the G2/M transition. DNA damage stabilizes CRY1 in cancer (in vitro, in vivo, and human tumors ex vivo), which proves critical for efficient DNA repair. Further mechanistic investigation shows that stabilized CRY1 temporally regulates expression of genes required …

Star-Related Lipid Transfer Protein 10 (Stard10): A Novel Key Player In Alcohol-Induced Breast Cancer Progression, Andrea Floris, Jia Luo, Jacqueline A. Frank, Jennifer Zhou, Sandro Orrù, Michela Biancolella, Sabina Pucci, Augusto Orlandi, Paolo Campagna, Antonella Balzano, Komal Ramani, Maria Lauda Tomasi

Pharmacology and Nutritional Sciences Faculty Publications

Background: Ethanol abuse promotes breast cancer development, metastasis and recurrence stimulating mammary tumorigenesis by mechanisms that remain unclear. Normally, 35% of breast cancer is Erb-B2 Receptor Tyrosine Kinase 2 (ERBB2)-positive that predisposes to poor prognosis and relapse, while ethanol drinking leads to invasion of their ERBB2 positive cells triggering the phosphorylation status of mitogen-activated protein kinase. StAR-related lipid transfer protein 10 (STARD10) is a lipid transporter of phosphatidylcholine (PC) and phosphatidylethanolamine (PE); changes on membrane composition of PC and PE occur before the morphological tumorigenic events. Interestingly, STARD10 has been described to be highly expressed in 35–40% of ERBB2-positive breast …

Nanoparticle Orientation To Control Rna Loading And Ligand Display On Extracellular Vesicles For Cancer Regression, Fengmei Pi, Daniel W. Binzel, Tae Jin Lee, Zhefeng Li, Meiyan Sun, Piotr G. Rychahou, Hui Li, Farzin Haque, Shaoying Wang, Carlo M. Croce, Bin Guo, B. Mark Evers, Peixuan Guo

Markey Cancer Center Faculty Publications

Nanotechnology offers many benefits, and here we report an advantage of applying RNA nanotechnology for directional control. The orientation of arrow-shaped RNA was altered to control ligand display on extracellular vesicle membranes for specific cell targeting, or to regulate intracellular trafficking of small interfering RNA (siRNA) or microRNA (miRNA). Placing membrane-anchoring cholesterol at the tail of the arrow results in display of RNA aptamer or folate on the outer surface of the extracellular vesicle. In contrast, placing the cholesterol at the arrowhead results in partial loading of RNA nanoparticles into the extracellular vesicles. Taking advantage of the RNA ligand for …

Abl Kinase Regulation By Braf/Erk And Cooperation With Akt In Melanoma, Aditi Jain, Rakshamani Tripathi, Courtney P. Turpin, Chi Wang, Rina Plattner

Pharmacology and Nutritional Sciences Faculty Publications

The melanoma incidence continues to increase, and the disease remains incurable for many due to its metastatic nature and high rate of therapeutic resistance. In particular, melanomas harboring BRAF^V600E and PTEN mutations often are resistant to current therapies, including BRAF inhibitors (BRAFi) and immune checkpoint inhibitors. Abl kinases (Abl/Arg) are activated in melanomas and drive progression; however, their mechanism of activation has not been established. Here we elucidate a novel link between BRAF^V600E/ERK signaling and Abl kinases. We demonstrate that BRAF^V600E/ERK play a critical role in binding, phosphorylating and regulating Abl localization and Abl/Arg activation …

A Naturally Generated Decoy Of The Prostate Apoptosis Response-4 Protein Overcomes Therapy Resistance In Tumors, Nikhil Hebbar, Ravshan Burikhanov, Nidhi Shukla, Shirley Qiu, Yanming Zhao, Kojo S. J. Elenitoba-Johnson, Vivek M. Rangnekar

Radiation Medicine Faculty Publications

Primary tumors are often heterogeneous, composed of therapy-sensitive and emerging therapy-resistant cancer cells. Interestingly, treatment of therapy-sensitive tumors in heterogeneous tumor microenvironments results in apoptosis of therapy-resistant tumors. In this study, we identify a prostate apoptosis response-4 (Par-4) amino-terminal fragment (PAF) that is released by diverse therapy-sensitive cancer cells following therapy-induced caspase cleavage of the tumor suppressor Par-4 protein. PAF caused apoptosis in cancer cells resistant to therapy and inhibited tumor growth. A VASA segment of Par-4 mediated its binding and degradation by the ubiquitin ligase Fbxo45, resulting in loss of Par-4 proapoptotic function. Conversely, PAF, which contains this VASA …

Temperature Induces Significant Changes In Both Glycolytic Reserve And Mitochondrial Spare Respiratory Capacity In Colorectal Cancer Cell Lines, Mihail I. Mitov, Jennifer W. Harris, Michael Alstott, Yekaterina Y. Zaytseva, B. Mark Evers, D. Allan Butterfield

Markey Cancer Center Faculty Publications

Thermotherapy, as a method of treating cancer, has recently attracted considerable attention from basic and clinical investigators. A number of studies and clinical trials have shown that thermotherapy can be successfully used as a therapeutic approach for various cancers. However, the effects of temperature on cancer bioenergetics have not been studied in detail with a real time, in a microplate, label-free detection approach.

This study investigate how changes in temperature affect the bioenergetics characteristics (mitochondrial function and glycolysis) of three colorectal cancer (CRC) cell lines utilizing the Seahorse XF96 technology. Experiments were performed at 32°C, 37°C and 42°C using assay …

P-Rex1 Promotes Resistance To Vegf/Vegfr-Targeted Therapy In Prostate Cancer, Hira Lal Goel, Bryan Pursell, Leonard D. Shultz, Dale L. Greiner, Rolf A Brekken, Craig W. Vander Kooi, Arthur M. Mercurio

Molecular and Cellular Biochemistry Faculty Publications

Autocrine VEGF signaling is critical for sustaining prostate and other cancer stem cells (CSCs), and it is a potential therapeutic target, but we observed that CSCs isolated from prostate tumors are resistant to anti-VEGF (bevacizumab) and anti-VEGFR (sunitinib) therapy. Intriguingly, resistance is mediated by VEGF/neuropilin signaling, which is not inhibited by bevacizumab and sunitinib, and it involves the induction of P-Rex1, a Rac GEF, and consequent Rac1-mediated ERK activation. This induction of P-Rex1 is dependent on Myc. CSCs isolated from the PTEN^pc−/− transgenic model of prostate cancer exhibit Rac1-dependent resistance to bevacizumab. Rac1 inhibition or P-Rex1 downregulation increases the …

Translation Initiation Complex Eif4f Is A Therapeutic Target For Dual Mtor Kinase Inhibitors In Non-Hodgkin Lymphoma., Christos Demosthenous, Jing Jing Han, Mary J Stenson, Matthew J Maurer, Linda E Wellik, Brian Link, Kristen Hege, Ahmet Dogan, Eduardo Sotomayor, Thomas Witzig, Mamta Gupta

Medicine Faculty Publications

Deregulated mRNA translation has been implicated in disease development and in part is controlled by a eukaryotic initiation complex eIF4F (composed of eIF4E, eIF4G and eIF4A). We demonstrate here that the cap bound fraction from lymphoma cells was enriched with eIF4G and eIF4E indicating that lymphoma cells exist in an activated translational state. Moreover, 77% (110/142) of diffuse large B cell lymphoma tumors expressed eIF4E and this was associated with an inferior event free survival. Over-expression of wild-type eIF4E (eIF4E(WT)) but not cap-mutant eIF4E (eIF4E(cap mutant)) increased the activation of the eIF4F complex. Treatment with the active-site dual mTOR inhibitor …

Clinical Significance Of A Point Mutation In Dna Polymerase Beta (Polb) Gene In Gastric Cancer., Xiaohui Tan, Hongyi Wang, Guangbin Luo, Shuyang Ren, Wenmei Li, Jiantao Cui, Harindarpal S. Gill, Sidney W. Fu, Youyong Lu

Medicine Faculty Publications

Gastric cancer (GC) is a major cause of global cancer mortality. Genetic variations in DNA repair genes can modulate DNA repair capability and, consequently, have been associated with risk of developing cancer. We have previously identified a T to C point mutation at nucleotide 889 (T889C) in DNA polymerase beta (POLB) gene, a key enzyme involved in base excision repair in primary GCs. The purpose of this study was to evaluate the mutation and expression of POLB in a larger cohort and to identify possible prognostic roles of the POLB alterations in GC. Primary GC specimens and their matched normal …

Coupling S100a4 To Rhotekin Alters Rho Signaling Output In Breast Cancer Cells, Min Chen, Anne R. Bresnick, Kathleen L. O'Connor

Markey Cancer Center Faculty Publications

Rho signaling is increasingly recognized to contribute to invasion and metastasis. In this study, we discovered that metastasis-associated protein S100A4 interacts with the Rho-binding domain (RBD) of Rhotekin, thus connecting S100A4 to the Rho pathway. Glutathione S-transferase pull-down and immunoprecipitation assays demonstrated that S100A4 specifically and directly binds to Rhotekin RBD, but not the other Rho effector RBDs. S100A4 binding to Rhotekin is calcium-dependent and uses residues distinct from those bound by active Rho. Interestingly, we found that S100A4 and Rhotekin can form a complex with active RhoA. Using RNA interference, we determined that suppression of both S100A4 and …

Inhibition Of Fatty Acid Synthase Attenuates Cd44-Associated Signaling And Reduces Metastasis In Colorectal Cancer, Yekaterina Y. Zaytseva, Piotr G. Rychahou, Pat Gulhati, Victoria Allison Elliott, William Conan Mustain, Kathleen O'Connor, Andrew J. Morris, Manjula Sunkara, Heidi L. Weiss, Eun Young Lee, B. Mark Evers

Markey Cancer Center Faculty Publications

Fatty acid synthase (FASN) and ATP-citrate lyase, key enzymes of de novo lipogenesis, are significantly upregulated and activated in many cancers and portend poor prognosis. Even though the role of lipogenesis in providing proliferative and survival advantages to cancer cells has been described, the impact of aberrant activation of lipogenic enzymes on cancer progression remains unknown. In this study, we found that elevated expression of FASN is associated with advanced stages of colorectal cancer (CRC) and liver metastasis, suggesting that it may play a role in progression of CRC to metastatic disease. Targeted inhibition of lipogenic enzymes abolished expression of …