Medicine and Health Sciences Commons^™

Novel Spirocyclic Dimer, Spid3, Targets Chronic Lymphocytic Leukemia Survival Pathways With Potent Preclinical Effects, Alexandria Eiken, Audrey L. Smith, Sydney A. Skupa, Elizabeth Schmitz, Sandeep Rana, Sarbjit Singh, Siddhartha Kumar, Jayapal Reddy Mallareddy, Aguirre A. De Cubas, Akshay Krishna, Achyuth Kalluchi, M. Jordan Rowley, Christopher R. D'Angelo, Matthew A. Lunning, Gregory Bociek, Julie M. Vose, Amarnath Natarajan, Dalia El-Gamal

Journal Articles: Oncology and Hematology

Chronic lymphocytic leukemia (CLL) cell survival and growth is fueled by the induction of B-cell receptor (BCR) signaling within the tumor microenvironment (TME) driving activation of NFκB signaling and the unfolded protein response (UPR). Malignant cells have higher basal levels of UPR posing a unique therapeutic window to combat CLL cell growth using pharmacologic agents that induce accumulation of misfolded proteins. Frontline CLL therapeutics that directly target BCR signaling such as Bruton tyrosine kinase (BTK) inhibitors (e.g., ibrutinib) have enhanced patient survival. However, resistance mechanisms wherein tumor cells bypass BTK inhibition through acquired BTK mutations, and/or activation of alternative survival …

Bet Inhibition Reforms The Immune Microenvironment And Alleviates T Cell Dysfunction In Chronic Lymphocytic Leukemia, Audrey L. Smith, Sydney A. Skupa, Alexandria P. Eiken, Timothy E. Reznicek, Elizabeth Schmitz, Nolan Williams, Dalia Y. Moore, Christopher R. D'Angelo, Avyakta Kallam, Matthew A. Lunning, Gregory Bociek, Julie M. Vose, Eslam Mohamed, Anna R. Mahr, Paul W. Denton, Ben Powell, Gideon Bollag, M. Jordan Rowley, Dalia El-Gamal

Journal Articles: Oncology and Hematology

Redundant tumor microenvironment (TME) immunosuppressive mechanisms and epigenetic maintenance of terminal T cell exhaustion greatly hinder functional antitumor immune responses in chronic lymphocytic leukemia (CLL). Bromodomain and extraterminal (BET) proteins regulate key pathways contributing to CLL pathogenesis and TME interactions, including T cell function and differentiation. Herein, we report that blocking BET protein function alleviates immunosuppressive networks in the CLL TME and repairs inherent CLL T cell defects. The pan-BET inhibitor OPN-51107 reduced exhaustion-associated cell signatures resulting in improved T cell proliferation and effector function in the Eμ-TCL1 splenic TME. Following BET inhibition (BET-i), TME T cells coexpressed significantly fewer …

Tgfβ/Smad3 Regulates Proliferation And Apoptosis Through Irs-1 Inhibition In Colon Cancer Cells., Katie L. Bailey, Ekta Agarwal, Sanjib Chowdhury, Jiangtao Luo, Michael G. Brattain, Jennifer D. Black, J. Wang

Journal Articles: Eppley Institute

In this study, we have uncovered a novel crosstalk between TGFβ and IGF-1R signaling pathways. We show for the first time that expression and activation of IRS-1, an IGF-1R adaptor protein, is decreased by TGFβ/Smad3 signaling. Loss or attenuation of TGFβ activation leads to elevated expression and phosphorylation of IRS-1 in colon cancer cells, resulting in enhanced cell proliferation, decreased apoptosis and increased tumor growth in vitro and in vivo. Downregulation of IRS-1 expression reversed Smad3 knockdown-mediated oncogenic phenotypes, indicating that TGFβ/Smad3 signaling inhibits cell proliferation and increases apoptosis at least partially through the inhibition of IRS-1 expression and activation. …

Muc1 Facilitates Metabolomic Reprogramming In Triple-Negative Breast Cancer, Gennifer Goode, Venugopal Gunda, Nina V. Chaika, Vinee Purohit, Fang Yu, Pankaj K. Singh

Journal Articles: Eppley Institute

BACKGROUND: Mucin1 (MUC1), a glycoprotein associated with chemoresistance and an aggressive cancer phenotype, is aberrantly overexpressed in triple-negative breast cancer (TNBC). Recent studies suggest that MUC1 plays a role in modulating cancer cell metabolism and thereby supports tumor growth. Herein, we examined the role of MUC1 in metabolic reprogramming in TNBC.

METHODS: MUC1 was stably overexpressed in MDA-MB-231 TNBC cells and stably knocked down in MDA-MB-468 cells. We performed liquid chromatography-coupled tandem mass spectrometry-assisted metabolomic analyses and physiological assays, which indicated significant alterations in the metabolism of TNBC cells due to MUC1 expression.

RESULTS: Differential analyses identified significant differences in …

Silibinin-Mediated Metabolic Reprogramming Attenuates Pancreatic Cancer-Induced Cachexia And Tumor Growth., Surendra K. Shukla, Aneesha Dasgupta, Kamiya Mehla, Venugopal Gunda, Enza Vernucci, Joshua J. Souchek, Gennifer Goode, Ryan King, Anusha Mishra, Ibha Rai, Sangeetha Nagarajan, Nina V. Chaika, Fang Yu, Surendra K. Shukla

Journal Articles: Eppley Institute

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related deaths in the US. Cancer-associated cachexia is present in up to 80% of PDAC patients and is associated with aggressive disease and poor prognosis. In the present studies we evaluated an anti-cancer natural product silibinin for its effectiveness in targeting pancreatic cancer aggressiveness and the cachectic properties of pancreatic cancer cells and tumors. Our results demonstrate that silibinin inhibits pancreatic cancer cell growth in a dose-dependent manner and reduces glycolytic activity of cancer cells. Our LC-MS/MS based metabolomics data demonstrates that silibinin treatment induces global metabolic reprogramming in pancreatic …

Ron Knockdown And Ron Monoclonal Antibody Imc-Ron8 Sensitize Pancreatic Cancer To Histone Deacetylase Inhibitors (Hdaci)., Yi Zou, Gillian M. Howell, Lisa E. Humphrey, J. Wang, Michael G. Brattain

Journal Articles: Eppley Institute

Recepteur d'origine nantais (Ron) is overexpressed in a panel of pancreatic cancer cells and tissue samples from pancreatic cancer patients. Ron can be activated by its ligand macrophage stimulating protein (MSP), thereby activating oncogenic signaling pathways. Crosstalk between Ron and EGFR, c-Met, or IGF-1R may provide a mechanism underlying drug resistance. Thus, targeting Ron may represent a novel therapeutic strategy. IMC-RON8 is the first Ron monoclonal antibody (mAb) entering clinical trial for targeting Ron overexpression. Our studies show IMC-RON8 downmodulated Ron expression in pancreatic cancer cells and significantly blocked MSP-stimulated Ron activation, downstream Akt and ERK phosphorylation, and survivin mRNA …

Microrna-183 Family Expression In Hair Cell Development And Requirement Of Micrornas For Hair Cell Maintenance And Survival, Michael D. Weston, Marsha L. Pierce, Heather Jensen Smith, Bernd Fritzsch, Sonia Rocha-Sanchez, Kirk W. Beisel, Garrett A. Soukup

Journal Articles: Eppley Institute

MicroRNAs (miRNAs) post-transcriptionally repress complementary target gene expression and can contribute to cell differentiation. The coordinate expression of miRNA-183 family members (miR-183, miR-96, and miR-182) has been demonstrated in sensory cells of the mouse inner ear and other vertebrate sensory organs. To further examine hair cell miRNA expression in the mouse inner ear, we have analyzed miR-183 family expression in wild type animals and various mutants with defects in neurosensory development. miR-183 family member expression follows neurosensory cell specification, exhibits longitudinal (basal-apical) gradients in maturating cochlear hair cells, and is maintained in sensory neurons and most hair cells into adulthood. …

Colon Carcinoma Cells Harboring Pik3ca Mutations Display Resistance To Growth Factor Deprivation Induced Apoptosis., J. Wang, Karen Kuropatwinski, Jennie Hauser, Michael R. Rossi, Yunfei Zhou, Alexis Conway, Julie L.C. Kan, Neil W. Gibson, James K.V. Willson, John K. Cowell, Michael G. Brattain

Journal Articles: Eppley Institute

PIK3CA, encoding the p110alpha catalytic subunit of phosphatidylinositol 3-kinase (PI3K), is mutated in a variety of human cancers. We screened the colon cancer cell lines previously established in our laboratory for PIK3CA mutations and found that four of them harbored gain of function mutations. We have now compared a panel of mutant and wild-type cell lines for cell proliferation and survival in response to stress. There was little difference in PI3K activity between mutant PIK3CA-bearing cells (mutant cells) and wild-type PIK3CA-bearing cells (wild-type cells) under optimal growth conditions. However, the mutant cells showed constitutive PI3K activity during growth factor deprivation …

Distinct Gene Expression Profiles In Different B-Cell Compartments In Human Peripheral Lymphoid Organs., Yulei Shen, Javeed Iqbal, Li Xiao, Ryan C. Lynch, Andreas Rosenwald, Louis M. Staudt, Simon Sherman, Karen Dybkaer, Guimei Zhou, James D. Eudy, Jan Delabie, Timothy W. Mckeithan, Wing C. Chan

Journal Articles: Eppley Institute

BACKGROUND: There are three major B-cell compartments in peripheral lymphoid organs: the germinal center (GC), the mantle zone (MNZ) and the marginal zone (MGZ). Unique sets of B-cells reside in these compartments, and they have specific functional roles in humoral immune response. MNZ B cells are naive cells in a quiescent state and may participate in GC reactions upon proper stimulation. The adult splenic MGZ contains mostly memory B cells and is also known to provide a rapid response to particulate antigens. The GC B-cells proliferate rapidly and undergo selection and affinity maturation. The B-cell maturational process is accompanied by …