Unique metabolic features of pancreatic cancer stroma: relevance to the tumor compartment, prognosis, and invasive potential.
Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis. The aggressiveness and therapeutic recalcitrance of this malignancy has been attributed to multiple factors including the influence of an active desmoplastic stroma. How the stromal microenvironment of PDAC contributes to the fatal nature of this disease is not well defined. In the analysis of clinical specimens, we observed diverse expression of the hypoxic marker carbonic anhydrase IX and the lactate transporter MCT4 in the stromal compartment. These stromal features were associated with the epithelial to mesenchymal phenotype in PDAC tumor cells, and with shorter patient survival. Cultured cancer-associated fibroblasts (CAFs) derived from primary PDAC exhibited a high basal level of hypoxia inducible factor 1a (HIF1α) that was both required and sufficient to modulate the expression of MCT4. This event was associated with increased transcription and protein synthesis of HIF1α in CAFs relative to PDAC cell lines, while surprisingly the protein turnover rate was equivalent. CAFs utilized glucose predominantly for glycolytic intermediates, whereas glutamine was the preferred metabolite for the TCA cycle. Unlike PDAC cell lines, CAFs were resistant to glucose withdrawal but sensitive to glutamine depletion. Consistent with the lack of reliance on glucose, CAFs could survive the acute depletion of MCT4. In co-culture and xenograft studies CAFs stimulated the invasive potential and metastatic spread of PDAC cell lines through a mechanism dependent on HIF1α and MCT4. Together, these data indicate that stromal metabolic features influence PDAC tumor cells to promote invasiveness and metastatic potential and associate with poor outcome in patients with PDAC.
McDermott Center for Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, USA.|Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.|University of Arizona Cancer Center, University of Arizona, Tucson, AZ, USA.|Department of Medicine, University of Arizona, Tucson, AZ, USA.
Erik S
ES
Knudsen
McDermott Center for Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Uthra
U
Balaji
Whitehead Institute, Massachusetts Institute of Technology, Cambridge, MA, USA.
Elizaveta
E
Freinkman
Department of Pathology, Thomas Jefferson University, Philadelphia, PA, USA.
Peter
P
McCue
McDermott Center for Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, USA.|Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.|University of Arizona Cancer Center, University of Arizona, Tucson, AZ, USA.|Department of Medicine, University of Arizona, Tucson, AZ, USA.|Department of Pathology, University of Arizona, Tucson, AZ, USA.
Agnieszka K
AK
Witkiewicz
D000818:Animals; D000951:Antigens, Neoplasm / Q000378:metabolism; D000072645:Cancer-Associated Fibroblasts / Q000378:metabolism* / Q000473:pathology; D000071231:Carbonic Anhydrase IX / Q000378:metabolism; D021441:Carcinoma, Pancreatic Ductal / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000556:secondary; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D004734:Energy Metabolism; D058750:Epithelial-Mesenchymal Transition; D015972:Gene Expression Regulation, Neoplastic; D005947:Glucose / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism; D053208:Kaplan-Meier Estimate; D051379:Mice; D027501:Monocarboxylic Acid Transporters / Q000235:genetics / Q000378:metabolism; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D009361:Neoplasm Invasiveness; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D010641:Phenotype; D016016:Proportional Hazards Models; D034622:RNA Interference; D017154:Stromal Cells / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors; D014158:Transcription, Genetic; D014162:Transfection; D000072258:Tumor Hypoxia; D059016:Tumor Microenvironment
D000951:Antigens, Neoplasm; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D027501:Monocarboxylic Acid Transporters; D009124:Muscle Proteins; C406962:SLC16A4 protein, human; D005973:Glutamine; C089226:CA9 protein, human; D000071231:Carbonic Anhydrase IX; D005947:Glucose