Medicine and Health Sciences Commons^™

Expression Of Carbonic Anhydrase Iii, A Nucleus Pulposus Phenotypic Marker, Is Hypoxia-Responsive And Confers Protection From Oxidative Stress-Induced Cell Death., Elizabeth S. Silagi, Philip Batista, Irving Shapiro, Makarand V. Risbud

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

The integrity of the avascular nucleus pulposus (NP) phenotype plays a crucial role in the maintenance of intervertebral disc health. While advances have been made to define the molecular phenotype of healthy NP cells, the functional relevance of several of these markers remains unknown. In this study, we test the hypothesis that expression of Carbonic Anhydrase III (CAIII), a marker of the notochordal NP, is hypoxia-responsive and functions as a potent antioxidant without a significant contribution to pH homeostasis. NP, but not annulus fibrosus or end-plate cells, robustly expressed CAIII protein in skeletally mature animals. Although CAIII expression was hypoxia-inducible, …

Scavenger Receptor Class B Type I Regulates Cellular Cholesterol Metabolism And Cell Signaling Associated With Breast Cancer Development., Christiane Danilo, Jorge L Gutierrez-Pajares, Maria Antonietta Mainieri, Isabelle Mercier, Michael P. Lisanti, Philippe G. Frank

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

INTRODUCTION: Previous studies have identified cholesterol as an important regulator of breast cancer development. High-density lipoprotein (HDL) and its cellular receptor, scavenger receptor class B type I (SR-BI) have both been implicated in the regulation of cellular cholesterol homeostasis, but their functions in cancer remain to be established.

METHODS: In the present study, we have examined the role of HDL and SR-BI in the regulation of cellular signaling pathways in breast cancer cell lines and in the development of tumor in a mouse xenograft model.

RESULTS: Our data show that HDL is capable of stimulating migration and can activate signal …

Cdk Inhibitors (P16/P19/P21) Induce Senescence And Autophagy In Cancer-Associated Fibroblasts, "Fueling" Tumor Growth Via Paracrine Interactions, Without An Increase In Neo-Angiogenesis., Claudia Capparelli, Barbara Chiavarina, Diana Whitaker-Menezes, Timothy G Pestell, Richard Pestell, James Hulit, Sebastiano Andò, Anthony Howell, Ubaldo E. Martinez-Outshoorn, Federica Sotgia, Michael P. Lisanti

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

Here, we investigated the compartment-specific role of cell cycle arrest and senescence in breast cancer tumor growth. For this purpose, we generated a number of hTERT-immortalized senescent fibroblast cell lines overexpressing CDK inhibitors, such as p16(INK4A), p19(ARF) or p21(WAF1/CIP1). Interestingly, all these senescent fibroblast cell lines showed evidence of increased susceptibility toward the induction of autophagy (either at baseline or after starvation), as well as significant mitochondrial dysfunction. Most importantly, these senescent fibroblasts also dramatically promoted tumor growth (up to ~2-fold), without any comparable increases in tumor angiogenesis. Conversely, we generated human breast cancer cells (MDA-MB-231 cells) overexpressing CDK inhibitors, …

Metabolic Remodeling Of The Tumor Microenvironment: Migration Stimulating Factor (Msf) Reprograms Myofibroblasts Toward Lactate Production, Fueling Anabolic Tumor Growth., Valentina Carito, Gloria Bonuccelli, Ubaldo E Martinez-Outschoorn, Diana Whitaker-Menezes, Maria Cristina Caroleo, Erika Cione, Anthony Howell, Richard G Pestell, Michael P. Lisanti, Federica Sotgia

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

Migration stimulating factor (MSF) is a genetically truncated N-terminal isoform of fibronectin that is highly expressed during mammalian development in fetal fibroblasts, and during tumor formation in human cancer-associated myofibroblasts. However, its potential functional role in regulating tumor metabolism remains unexplored. Here, we generated an immortalized fibroblast cell line that recombinantly overexpresses MSF and studied their properties relative to vector-alone control fibroblasts. Our results indicate that overexpression of MSF is sufficient to confer myofibroblastic differentiation, likely via increased TGF-b signaling. In addition, MSF activates the inflammation-associated transcription factor NFκB, resulting in the onset of autophagy/mitophagy, thereby driving glycolytic metabolism (L-lactate …

Two-Compartment Tumor Metabolism: Autophagy In The Tumor Microenvironment And Oxidative Mitochondrial Metabolism (Oxphos) In Cancer Cells., Ahmed F Salem, Diana Whitaker-Menezes, Zhao Lin, Ubaldo E. Martinez-Outshoorn, Herbert B Tanowitz, Mazhar Salim Al-Zoubi, Anthony Howell, Richard Pestell, Federica Sotgia, Michael P. Lisanti

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

Previously, we proposed a new paradigm to explain the compartment-specific role of autophagy in tumor metabolism. In this model, autophagy and mitochondrial dysfunction in the tumor stroma promotes cellular catabolism, which results in the production of recycled nutrients. These chemical building blocks and high-energy "fuels" would then drive the anabolic growth of tumors, via autophagy resistance and oxidative mitochondrial metabolism in cancer cells. We have termed this new form of stromal-epithelial metabolic coupling: "two-compartment tumor metabolism." Here, we stringently tested this energy-transfer hypothesis, by genetically creating (1) constitutively autophagic fibroblasts, with mitochondrial dysfunction or (2) autophagy-resistant cancer cells, with increased …

Autophagy And Senescence In Cancer-Associated Fibroblasts Metabolically Supports Tumor Growth And Metastasis Via Glycolysis And Ketone Production., Claudia Capparelli, Carmela Guido, Diana Whitaker-Menezes, Phd, Gloria Bonuccelli, Renee Balliet, Timothy G Pestell, Allison F Goldberg, Richard Pestell, Anthony Howell, Sharon Sneddon, Ruth Birbe, Aristotelis Tsirigos, Ubaldo E. Martinez-Outshoorn, Federica Sotgia, Michael P. Lisanti

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

Senescent fibroblasts are known to promote tumor growth. However, the exact mechanism remains largely unknown. An important clue comes from recent studies linking autophagy with the onset of senescence. Thus, autophagy and senescence may be part of the same physiological process, known as the autophagy-senescence transition (AST). To test this hypothesis, human fibroblasts immortalized with telomerase (hTERT-BJ1) were stably transfected with autophagy genes (BNIP3, CTSB or ATG16L1). Their overexpression was sufficient to induce a constitutive autophagic phenotype, with features of mitophagy, mitochondrial dysfunction and a shift toward aerobic glycolysis, resulting in L-lactate and ketone body production. Autophagic fibroblasts also showed …

Ctgf Drives Autophagy, Glycolysis And Senescence In Cancer-Associated Fibroblasts Via Hif1 Activation, Metabolically Promoting Tumor Growth., Claudia Capparelli, Diana Whitaker-Menezes, Carmela Guido, Renee Balliet, Timothy G Pestell, Anthony Howell, Sharon Sneddon, Richard Pestell, Ubaldo E. Martinez-Outshoorn, Michael P. Lisanti, Federica Sotgia

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

Previous studies have demonstrated that loss of caveolin-1 (Cav-1) in stromal cells drives the activation of the TGF-β signaling, with increased transcription of TGF-β target genes, such as connective tissue growth factor (CTGF). In addition, loss of stromal Cav-1 results in the metabolic reprogramming of cancer-associated fibroblasts, with the induction of autophagy and glycolysis. However, it remains unknown if activation of the TGF-β / CTGF pathway regulates the metabolism of cancer-associated fibroblasts. Therefore, we investigated whether CTGF modulates metabolism in the tumor microenvironment. For this purpose, CTGF was overexpressed in normal human fibroblasts or MDA-MB-231 breast cancer cells. Overexpression of …

Pressure-Overload-Induced Subcellular Relocalization/Oxidation Of Soluble Guanylyl Cyclase In The Heart Modulates Enzyme Stimulation., Emily J Tsai, Yuchuan Liu, Norimichi Koitabashi, Djahida Bedja, Thomas Danner, Jean-Francois Jasmin, Michael P Lisanti, Andreas Friebe, Eiki Takimoto, David A Kass

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

RATIONALE: Soluble guanylyl cyclase (sGC) generates cyclic guanosine monophophate (cGMP) upon activation by nitric oxide (NO). Cardiac NO-sGC-cGMP signaling blunts cardiac stress responses, including pressure-overload-induced hypertrophy. The latter itself depresses signaling through this pathway by reducing NO generation and enhancing cGMP hydrolysis.

OBJECTIVE: We tested the hypothesis that the sGC response to NO also declines with pressure-overload stress and assessed the role of heme-oxidation and altered intracellular compartmentation of sGC as potential mechanisms.

METHODS AND RESULTS: C57BL/6 mice subjected to transverse aortic constriction (TAC) developed cardiac hypertrophy and dysfunction. NO-stimulated sGC activity was markedly depressed, whereas NO- and heme-independent sGC …

Understanding The Warburg Effect And The Prognostic Value Of Stromal Caveolin-1 As A Marker Of A Lethal Tumor Microenvironment., Federica Sotgia, Ubaldo E Martinez-Outschoorn, Stephanos Pavlides, Anthony Howell, Richard G. Pestell, Michael P Lisanti

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

Cancer cells show a broad spectrum of bioenergetic states, with some cells using aerobic glycolysis while others rely on oxidative phosphorylation as their main source of energy. In addition, there is mounting evidence that metabolic coupling occurs in aggressive tumors, between epithelial cancer cells and the stromal compartment, and between well-oxygenated and hypoxic compartments. We recently showed that oxidative stress in the tumor stroma, due to aerobic glycolysis and mitochondrial dysfunction, is important for cancer cell mutagenesis and tumor progression. More specifically , increased autophagy/mitophagy in the tumor stroma drives a form of parasitic epithelial-stromal metabolic coupling. These findings explain …

Mitochondrial Oxidative Stress Drives Tumor Progression And Metastasis: Should We Use Antioxidants As A Key Component Of Cancer Treatment And Prevention?, Federica Sotgia, Ubaldo E Martinez-Outschoorn, Michael P Lisanti

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

The functional role of oxidative stress in cancer pathogenesis has long been a hotly debated topic. A study published this month in BMC Cancer by Goh et al., directly addresses this issue by using a molecular genetic approach, via an established mouse animal model of human breast cancer. More specifically, alleviation of mitochondrial oxidative stress, via transgenic over-expression of catalase (an anti-oxidant enzyme) targeted to mitochondria, was sufficient to lower tumor grade (from high-to-low) and to dramatically reduce metastatic tumor burden by >12-fold. Here, we discuss these new findings and place them in the context of several other recent studies …