Person: Wargo, Jennifer Ann
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Wargo
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Jennifer Ann
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Wargo, Jennifer Ann
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Publication PDGFRα up-regulation mediated by sonic hedgehog pathway activation leads to BRAF inhibitor resistance in melanoma cells with BRAF mutation(Impact Journals LLC, 2014) Sabbatino, Francesco; Wang, YangYang; Wang, Xinhui; Flaherty, Keith; Yu, Ling; Pepin, David; Scognamiglio, Giosue'; Pepe, Stefano; Kirkwood, John M.; Cooper, Zachary A.; Frederick, Dennie T.; Wargo, Jennifer Ann; Ferrone, Soldano; Ferrone, CristinaControl of BRAF(V600E) metastatic melanoma by BRAF inhibitor (BRAF-I) is limited by intrinsic and acquired resistance. Growth factor receptor up-regulation is among the mechanisms underlying BRAF-I resistance of melanoma cells. Here we demonstrate for the first time that PDGFRα up-regulation causes BRAF-I resistance. PDGFRα inhibition by PDGFRα-specific short hairpin (sh)RNA and by PDGFRα inhibitors restores and increases melanoma cells' sensitivity to BRAF-I in vitro and in vivo. This effect reflects the inhibition of ERK and AKT activation which is associated with BRAF-I resistance of melanoma cells. PDGFRα up-regulation is mediated by Sonic Hedgehog Homolog (Shh) pathway activation which is induced by BRAF-I treatment. Similarly to PDGFRα inhibition, Shh inhibition by LDE225 restores and increases melanoma cells' sensitivity to BRAF-I. These effects are mediated by PDGFRα down-regulation and by ERK and AKT inhibition. The clinical relevance of these data is indicated by the association of PDGFRα up-regulation in melanoma matched biopsies of BRAF-I +/- MEK inhibitor treated patients with shorter time to disease progression and less tumor regression. These findings suggest that monitoring patients for early PDGFRα up-regulation will facilitate the identification of those who may benefit from the treatment with BRAF-I in combination with clinically approved PDGFRα or Shh inhibitors.Publication Tumor microenvironment induces innate RAF-inhibitor resistance through HGF secretion(2012) Straussman, Ravid; Morikawa, Teppei; Shee, Kevin; Barzily-Rokni, Michal; Qian, Zhi Rong; Du, Jinyan; Davis, Ashli; Mongare, Margaret M.; Gould, Joshua; Frederick, Dennie T.; Cooper, Zachary A.; Chapman, Paul B.; Solit, David B.; Ribas, Antoni; Lo, Roger S.; Flaherty, Keith; Ogino, Shuji; Wargo, Jennifer Ann; Golub, ToddDrug resistance remains a vexing problem in the treatment of cancer patients. While many studies have focused on cell autonomous mechanisms of drug resistance, we hypothesized that the tumor microenvironment may confer innate resistance to therapy. Here we developed a co-culture system to systematically assay the ability of 23 stromal cell types to influence the innate resistance of 45 cancer cell lines to 35 anti-cancer drugs. We found that stroma-mediated resistance is surprisingly common – particularly to targeted agents. We further characterized the stroma-mediated resistance of BRAF-mutant melanoma to RAF inhibition because most of these patients exhibit some degree of innate resistance1-4. Proteomic analysis showed that stromal secretion of the growth factor hepatocyte growth factor (HGF) resulted in activation of the HGF receptor MET, reactivation of the MAPK and PI3K/AKT pathways, and immediate resistance to RAF inhibition. Immunohistochemistry confirmed stromal HGF expression in patients with BRAF-mutant melanoma and a statistically significant correlation between stromal HGF expression and innate resistance to treatment. Dual inhibition of RAF and MET resulted in reversal of drug resistance, suggesting RAF/MET combination therapy as a potential therapeutic strategy for BRAF-mutant melanoma. A similar resistance mechanism was uncovered in a subset of BRAF-mutant colorectal and glioblastoma cell lines. More generally, these studies indicate that the systematic dissection of tumor-microenvironment interactions may reveal important mechanisms underlying drug resistance.Publication Pancreatic Ductal Adenocarcinoma(Ovid Technologies (Wolters Kluwer Health), 2013) Konstantinidis, Ioannis T; Warshaw, Andrew; Allen, Jill; Blaszkowsky, Lawrence; Castillo, Carlos; Deshpande, Vikram; Hong, Theodore; Kwak, Eunice Lee; Lauwers, Gregory Y.; Ryan, David; Wargo, Jennifer Ann; Lillemoe, Keith; Ferrone, CristinaObjective: Patients who undergo an R0 resection of their pancreatic ductal adenocarcinoma (PDAC) have an improved survival compared with patients who undergo an R1 resection. It is unclear whether an R1 resection confers a survival benefit over locally advanced (LA) unresectable tumors. Our aim was to compare the survival of patients undergoing an R1 resection with those having LA tumors and to explore the prognostic significance of a 1-mm surgical margin. Methods: Clinicopathologic data from a pancreatic cancer database between January 1993 and July 2008 were reviewed. Locally advanced tumors had no evidence of metastatic disease at exploration. Results: A total of 1705 patients were evaluated for PDAC in the Department of Surgery. Of the 1084 (64%) patients who were surgically explored, 530 (49%) were considered unresectable (286 locally unresectable, 244 with distant metastasis). One hundred fifty-seven (28%) of the resected PDACs had an R1 resection. Patients undergoing an R1 resection had a slightly longer survival compared with those who had locally advanced unresectable cancers (14 vs 11 months; P < 0.001). Patients with R0 resections had a favorable survival compared with those with R1 resections (23 vs 14 months; P < 0.001), but survival after resections with 1-mm margin or less (R0-close) were similar to R1 resections: both groups had a significantly shorter median survival than patients with a margin of greater than 1 mm (R0-wide) (16 vs 14 vs 35 months, respectively; P < 0.001). Conclusions: Patients undergoing an R1 resection still have an improved survival compared with patients with locally advanced unresectable pancreatic adenocarcinoma. R0 resections have an improved survival compared with R1 resections, but this survival benefit is lost when the tumor is within 1 mm of the resection margin.Publication Pancreatic Ductal Adenocarcinoma: Long-Term Survival Does Not Equal Cure(Elsevier BV, 2012) Ferrone, Cristina; Pieretti-Vanmarcke, Rafael; Bloom, Jordan; Zheng, Hui; Szymonifka, Jackye; Wargo, Jennifer Ann; Thayer, Sarah P.; Lauwers, Gregory Y.; Deshpande, Vikram; Mino-Kenudson, Mari; Fernandez-Del Castillo, Carlos; Lillemoe, Keith; Warshaw, AndrewBackground: Pancreatic ductal adenocarcinoma represents 90% of pancreatic cancers and is an important cause of cancer death in the United States. Operative resection remains as the only treatment providing prolonged survival, but even after a curative resection, 5-year survival rates are low. Our aim was to identify the prognostic factors for long-term survival after resection of pancreatic ductal adenocarcinoma related to patients, treatments, and tumor biology. Methods: Retrospective review identified 959 patients who underwent resection of their pancreatic adenocarcinoma between February 1985 and December 2010, of whom 499 were resected before November 2006 and represent the cohort we describe in this study. Patient, tumor, and treatment-related variables were assessed for their associations with 5- and 10-year overall survival. Results: Of the 499 patients, 49% were female and median age was 65 years. The majority of patients had stage IIb disease (60%). Actual 5-year survival after resection of pancreatic adenocarcinoma was 19% (95/499), and actual 10-year survival was 10% (33/329). Significant clinicopathologic factors predicting 5- and 10-year survival were negative margins and negative nodal status. Interestingly, 41% (39/95) of long-term survivors had positive nodes and 24% (23/95) had positive margins. Conclusion: Pancreatic ductal adenocarcinoma demonstrates a very heterogeneous biology, but patients with negative resection margins and node negative cancers are more likely to survive 5 years after resection. However, our series demonstrates that the biology of the cancer rather than simple pathologic factors determine a patient's prognosis.Publication A melanocyte lineage program confers resistance to MAP kinase pathway inhibition(2014) Johannessen, Cory M.; Johnson, Laura A.; Piccioni, Federica; Townes, Aisha; Frederick, Dennie T.; Donahue, Melanie K.; Narayan, Rajiv; Flaherty, Keith; Wargo, Jennifer Ann; Root, David E.; Garraway, LeviBRAFV600E-mutant malignant melanomas depend on RAF/MEK/ERK (MAPK) signaling for tumor cell growth1. RAF and MEK inhibitors show remarkable clinical efficacy in BRAFV600E melanoma2, 3; however, resistance to these agents remains a formidable challenge2, 4. Global characterization of resistance mechanisms may inform the development of more effective therapeutic combinations. Here, we performed systematic gain-of-function resistance studies by expressing >15,500 genes individually in a BRAFV600E melanoma cell line treated with RAF, MEK, ERK, or combined RAF/MEK inhibitors. These studies revealed a cyclic AMP-dependent melanocytic signaling network not previously associated with drug resistance, including G-protein coupled receptors, adenyl cyclase, protein kinase A and cAMP response element binding protein (CREB). Preliminary analysis of biopsies from BRAFV600E melanoma patients revealed that phosphorylated (active) CREB was suppressed by RAF/MEK-inhibition but restored in relapsing tumors. Expression of transcription factors activated downstream of MAP kinase and cAMP pathways also conferred resistance, including c-FOS, NR4A1, NR4A2 and MITF. Combined treatment with MAP kinase pathway and histone deacetylase inhibitors suppressed MITF expression and cAMP-mediated resistance. Collectively, these data suggest that oncogenic dysregulation of a melanocyte lineage dependency can cause resistance to RAF/MEK/ERK inhibition, which may be overcome by combining signaling- and chromatin-directed therapeutics.Publication Melanoma genome sequencing reveals frequent PREX2 mutations(2012) Berger, Michael F.; Hodis, Eran; Heffernan, Timothy P.; Deribe, Yonathan Lissanu; Lawrence, Michael S.; Protopopov, Alexei; Ivanova, Elena; Watson, Ian; Nickerson, Elizabeth; Ghosh, Papia; Zhang, Hailei; Zeid, Rhamy; Ren, Xiaojia; Cibulskis, Kristian; Sivachenko, Andrey Y.; Wagle, Nikhil; Sucker, Antje; Sougnez, Carrie; Onofrio, Roberto; Ambrogio, Lauren; Auclair, Daniel; Fennell, Timothy; Carter, Scott L.; Drier, Yotam; Stojanov, Petar; Singer, Meredith A.; Voet, Douglas; Jing, Rui; Saksena, Gordon; Barretina, Jordi; Ramos, Alex H.; Pugh, Trevor J.; Stransky, Nicolas; Parkin, Melissa Ann; Winckler, Wendy; Mahan, Scott; Ardlie, Kristin; Baldwin, Jennifer; Wargo, Jennifer Ann; Schadendorf, Dirk; Meyerson, Matthew; Gabriel, Stacey B.; Golub, Todd; Wagner, Stephan N.; Lander, Eric; Getz, Gad; Chin, Lynda; Garraway, LeviMelanoma is notable for its metastatic propensity, lethality in the advanced setting, and association with ultraviolet (UV) exposure early in life1. To obtain a comprehensive genomic view of melanoma, we sequenced the genomes of 25 metastatic melanomas and matched germline DNA. A wide range of point mutation rates was observed: lowest in melanomas whose primaries arose on non-UV exposed hairless skin of the extremities (3 and 14 per Mb genome), intermediate in those originating from hair-bearing skin of the trunk (range = 5 to 55 per Mb), and highest in a patient with a documented history of chronic sun exposure (111 per Mb). Analysis of whole-genome sequence data identified PREX2 - a PTEN-interacting protein and negative regulator of PTEN in breast cancer2 - as a significantly mutated gene with a mutation frequency of approximately 14% in an independent extension cohort of 107 human melanomas. PREX2 mutations are biologically relevant, as ectopic expression of mutant PREX2 accelerated tumor formation of immortalized human melanocytes in vivo. Thus, whole-genome sequencing of human melanoma tumors revealed genomic evidence of UV pathogenesis and discovered a new recurrently mutated gene in melanoma.Publication Does the Mechanism of Lymph Node Invasion Affect Survival in Patients with Pancreatic Ductal Adenocarcinoma?(Springer Science + Business Media, 2010) Konstantinidis, Ioannis T; Deshpande, Vikram; Zheng, Hui; Wargo, Jennifer Ann; Fernandez-Del Castillo, Carlos; Thayer, Sarah P.; Androutsopoulos, Vasiliki; Lauwers, Gregory Y.; Warshaw, Andrew; Ferrone, CristinaBackground: Lymph node metastases are prognostically significant in pancreatic ductal adenocarcinoma. Little is known about the significance of direct lymph node invasion. Aim: The aim of this study is to find out whether direct lymph node invasion has the same prognostic significance as regional nodal metastases. Methods: Retrospective review of patients resected between 1/1/1993 and 7/31/2008. “Direct” was defined as tumor extension into adjacent nodes, and “regional” was defined as metastases to peripancreatic nodes. Results: Overall, 517 patients underwent pancreatic resection for adenocarcinoma, of whom 89 had one positive node (direct 26, regional 63), and 79 had two positive nodes (direct 6, regional 68, both 5). Overall, survival of node-negative patients was improved compared to patients with positive nodes (N0 30.8 months vs. N1 16.4 months; p < 0.001). There was no survival difference for patients with direct vs. regional lymph node invasion (p = 0.67). Patients with one positive node had a better overall survival compared to patients with ≥2 positive nodes (22.3 and 15 months, respectively; p < 0.001). The lymph node ratio (+LN/total LN) was prognostically significant after Cox regression (p < 0.001). Conclusions: Isolated direct invasion occurs in 20% of patients with one to two positive nodes. Node involvement by metastasis or by direct invasion are equally significant predictors of reduced survival. Both the number of positive nodes and the lymph node ratio are significant prognostic factors.