Mammary adipocytes stimulate breast cancer invasion through metabolic remodeling of tumor cells

• Text
• PDF

Abstract

In breast cancer, a key feature of peritumoral adipocytes is their loss of lipid content observed both in vitro and in human tumors. The free fatty acids (FFAs), released by adipocytes after lipolysis induced by tumor secretions, are transferred and stored in tumor cells as triglycerides in lipid droplets. In tumor cell lines, we demonstrate that FFAs can be released over time from lipid droplets through an adipose triglyceride lipase–dependent (ATGL-dependent) lipolytic pathway. In vivo, ATGL is expressed in human tumors where its expression correlates with tumor aggressiveness and is upregulated by contact with adipocytes. The released FFAs are then used for fatty acid β-oxidation (FAO), an active process in cancer but not normal breast epithelial cells, and regulated by coculture with adipocytes. However, in cocultivated cells, FAO is uncoupled from ATP production, leading to AMPK/acetyl-CoA carboxylase activation, a circle that maintains this state of metabolic remodeling. The increased invasive capacities of tumor cells induced by coculture are completely abrogated by inhibition of the coupled ATGL-dependent lipolysis/FAO pathways. These results show a complex metabolic symbiosis between tumor-surrounding adipocytes and cancer cells that stimulate their invasiveness, highlighting ATGL as a potential therapeutic target to impede breast cancer progression.

Authors

Yuan Yuan Wang, Camille Attané, Delphine Milhas, Béatrice Dirat, Stéphanie Dauvillier, Adrien Guerard, Julia Gilhodes, Ikrame Lazar, Nathalie Alet, Victor Laurent, Sophie Le Gonidec, Denis Biard, Caroline Hervé, Frédéric Bost, Guo Sheng Ren, Françoise Bono, Ghislaine Escourrou, Marc Prentki, Laurence Nieto, Philippe Valet, Catherine Muller

BET inhibitors block pancreatic stellate cell collagen I production and attenuate fibrosis in vivo

• Text
• PDF

Abstract

The fibrotic reaction, which can account for over 70%–80% of the tumor mass, is a characteristic feature of human pancreatic ductal adenocarcinoma (PDAC) tumors. It is associated with activation and proliferation of pancreatic stellate cells (PSCs), which are key regulators of collagen I production and fibrosis in vivo. In this report, we show that members of the bromodomain and extraterminal (BET) family of proteins are expressed in primary PSCs isolated from human PDAC tumors, with BRD4 positively regulating, and BRD2 and BRD3 negatively regulating, collagen I expression in primary cancer-associated PSCs. We show that the inhibitory effect of pan-BET inhibitors on collagen I expression in primary cancer-associated PSCs is through blocking of BRD4 function. Importantly, we show that FOSL1 is repressed by BRD4 in primary cancer-associated PSCs and negatively regulates collagen I expression. While BET inhibitors do not affect viability or induce PSC apoptosis or senescence, BET inhibitors induce primary cancer-associated PSCs to become quiescent. Finally, we show that BET inhibitors attenuate stellate cell activation, fibrosis, and collagen I production in the EL-Kras^G12D transgenic mouse model of pancreatic tumorigenesis. Our results demonstrate that BET inhibitors regulate fibrosis by modulating the activation and function of cancer-associated PSCs.

Authors

Krishan Kumar, Brian T. DeCant, Paul J. Grippo, Rosa F. Hwang, David J. Bentrem, Kazumi Ebine, Hidayatullah G. Munshi

Real-time genomic profiling of histiocytoses identifies early-kinase domain BRAF alterations while improving treatment outcomes

• Text
• PDF

Abstract

Many patients with histiocytic disorders such as Langerhans cell histiocytosis (LCH) or Erdheim-Chester disease (ECD) have treatment-refractory disease or suffer recurrences. Recent findings of gene mutations in histiocytoses have generated options for targeted therapies. We sought to determine the utility of prospective sequencing of select genes to further characterize mutations and identify targeted therapies for patients with histiocytoses. Biopsies of 72 patients with a variety of histiocytoses underwent comprehensive genomic profiling with targeted DNA and RNA sequencing. Fifteen patients (21%) carried the known BRAF V600E mutation, and 11 patients (15%) carried various mutations in MAP2K1, which we confirm induce constitutive activation of extracellular signal–regulated kinase (ERK) and were sensitive to inhibitors of mitogen-activated protein kinase kinase (MEK, the product of MAP2K1). We also identified recurring ALK rearrangements, and 4 LCH patients with an uncommon in-frame deletion in BRAF (N486_P490del or N486_T491>K), resulting in constitutive activation of ERK with resistance to V600E-specific inhibitors. We subsequently describe clinical cases where patients with aggressive multisystem LCH experience dramatic and sustained responses to monotherapy with either dabrafenib or trametinib. These findings support our conclusion that comprehensive genomic profiling should be regularly applied to these disorders at diagnosis, and can positively impact clinical care.

Authors

Lynn H. Lee, Anjelika Gasilina, Jayeeta Roychoudhury, Jason Clark, Francis X. McCormack, Joseph Pressey, Michael S. Grimley, Robert Lorsbach, Siraj Ali, Mark Bailey, Philip Stephens, Jeffrey S. Ross, Vincent A. Miller, Nicolas N. Nassar, Ashish R. Kumar

An early-biomarker algorithm predicts lethal graft-versus-host disease and survival

• Text
• PDF

Abstract

BACKGROUND. No laboratory test can predict the risk of nonrelapse mortality (NRM) or severe graft-versus-host disease (GVHD) after hematopoietic cellular transplantation (HCT) prior to the onset of GVHD symptoms.

METHODS. Patient blood samples on day 7 after HCT were obtained from a multicenter set of 1,287 patients, and 620 samples were assigned to a training set. We measured the concentrations of 4 GVHD biomarkers (ST2, REG3α, TNFR1, and IL-2Rα) and used them to model 6-month NRM using rigorous cross-validation strategies to identify the best algorithm that defined 2 distinct risk groups. We then applied the final algorithm in an independent test set (n = 309) and validation set (n = 358).

RESULTS. A 2-biomarker model using ST2 and REG3α concentrations identified patients with a cumulative incidence of 6-month NRM of 28% in the high-risk group and 7% in the low-risk group (P < 0.001). The algorithm performed equally well in the test set (33% vs. 7%, P < 0.001) and the multicenter validation set (26% vs. 10%, P < 0.001). Sixteen percent, 17%, and 20% of patients were at high risk in the training, test, and validation sets, respectively. GVHD-related mortality was greater in high-risk patients (18% vs. 4%, P < 0.001), as was severe gastrointestinal GVHD (17% vs. 8%, P < 0.001). The same algorithm can be successfully adapted to define 3 distinct risk groups at GVHD onset.

CONCLUSION. A biomarker algorithm based on a blood sample taken 7 days after HCT can consistently identify a group of patients at high risk for lethal GVHD and NRM.

FUNDING. The National Cancer Institute, American Cancer Society, and the Doris Duke Charitable Foundation.

Authors

Matthew J. Hartwell, Umut Özbek, Ernst Holler, Anne S. Renteria, Hannah Major-Monfried, Pavan Reddy, Mina Aziz, William J. Hogan, Francis Ayuk, Yvonne A. Efebera, Elizabeth O. Hexner, Udomsak Bunworasate, Muna Qayed, Rainer Ordemann, Matthias Wölfl, Stephan Mielke, Attaphol Pawarode, Yi-Bin Chen, Steven Devine, Andrew C. Harris, Madan Jagasia, Carrie L. Kitko, Mark R. Litzow, Nicolaus Kröger, Franco Locatelli, George Morales, Ryotaro Nakamura, Ran Reshef, Wolf Rösler, Daniela Weber, Kitsada Wudhikarn, Gregory A. Yanik, John E. Levine, James L.M. Ferrara

Diverse repetitive element RNA expression defines epigenetic and immunologic features of colon cancer

• Text
• PDF

Abstract

There is tremendous excitement for the potential of epigenetic therapies in cancer, but the ability to predict and monitor response to these drugs remains elusive. This is in part due to the inability to differentiate the direct cytotoxic and the immunomodulatory effects of these drugs. The DNA-hypomethylating agent 5-azacitidine (AZA) has shown these distinct effects in colon cancer and appears to be linked to the derepression of repeat RNAs. LINE and HERV are two of the largest classes of repeats in the genome, and despite many commonalities, we found that there is heterogeneity in behavior among repeat subtypes. Specifically, the LINE-1 and HERV-H subtypes detected by RNA sequencing and RNA in situ hybridization in colon cancers had distinct expression patterns, which suggested that these repeats are correlated to transcriptional programs marking different biological states. We found that low LINE-1 expression correlates with global DNA hypermethylation, wild-type TP53 status, and responsiveness to AZA. HERV-H repeats were not concordant with LINE-1 expression but were found to be linked with differences in FOXP3⁺ Treg tumor infiltrates. Together, distinct repeat RNA expression patterns define new molecular classifications of colon cancer and provide biomarkers that better distinguish cytotoxic from immunomodulatory effects by epigenetic drugs.

Authors

Niyati Desai, Dipti Sajed, Kshitij S. Arora, Alexander Solovyov, Mihir Rajurkar, Jacob R. Bledsoe, Srinjoy Sil, Ramzi Amri, Eric Tai, Olivia C. MacKenzie, Mari Mino-Kenudson, Martin J. Aryee, Cristina R. Ferrone, David L. Berger, Miguel N. Rivera, Benjamin D. Greenbaum, Vikram Deshpande, David T. Ting

GLUT3 upregulation promotes metabolic reprogramming associated with antiangiogenic therapy resistance

• Text
• PDF

Abstract

Clinical trials revealed limited response duration of glioblastomas to VEGF-neutralizing antibody bevacizumab. Thriving in the devascularized microenvironment occurring after antiangiogenic therapy requires tumor cell adaptation to decreased glucose, with 50% less glucose identified in bevacizumab-treated xenografts. Compared with bevacizumab-responsive xenograft cells, resistant cells exhibited increased glucose uptake, glycolysis, ¹³C NMR pyruvate to lactate conversion, and survival in low glucose. Glucose transporter 3 (GLUT3) was upregulated in bevacizumab-resistant versus sensitive xenografts and patient specimens in a HIF-1α–dependent manner. Resistant versus sensitive cell mitochondria in oxidative phosphorylation–selective conditions produced less ATP. Despite unchanged mitochondrial numbers, normoxic resistant cells had lower mitochondrial membrane potential than sensitive cells, confirming poorer mitochondrial health, but avoided the mitochondrial dysfunction of hypoxic sensitive cells. Thin-layer chromatography revealed increased triglycerides in bevacizumab-resistant versus sensitive xenografts, a change driven by mitochondrial stress. A glycogen synthase kinase-3β inhibitor suppressing GLUT3 transcription caused greater cell death in bevacizumab-resistant than -responsive cells. Overexpressing GLUT3 in tumor cells recapitulated bevacizumab-resistant cell features: survival and proliferation in low glucose, increased glycolysis, impaired oxidative phosphorylation, and rapid in vivo proliferation only slowed by bevacizumab to that of untreated bevacizumab-responsive tumors. Targeting GLUT3 or the increased glycolysis reliance in resistant tumors could unlock the potential of antiangiogenic treatments.

Authors

Ruby Kuang, Arman Jahangiri, Smita Mascharak, Alan Nguyen, Ankush Chandra, Patrick M. Flanigan, Garima Yagnik, Jeffrey R. Wagner, Michael De Lay, Diego Carrera, Brandyn A. Castro, Josie Hayes, Maxim Sidorov, Jose Luiz Izquierdo Garcia, Pia Eriksson, Sabrina Ronen, Joanna Phillips, Annette Molinaro, Suneil Koliwad, Manish K. Aghi

Prostatic compensation of the vitamin D axis in African American men

• Text
• PDF

Abstract

BACKGROUND. African American (AA) men are disproportionately affected by both prostate cancer (PCa) and vitamin D deficiency compared with European American (EA) men. Vitamin D deficiency is linked to increased PCa aggressiveness and mortality. Therefore, it has been hypothesized that vitamin D deficiency may contribute to the PCa disparity between AA and EA men.

METHODS. We studied a cross sectional group of 60 PCa patients (AA, n = 31; EA, n = 29) who underwent radical prostatectomy. Vitamin D metabolites 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)₂D) were measured in the serum and tissue by uHPLC-MS-MS. Tissue was laser capture microdissected, and gene expression was quantified by microarray. DNA isolated from whole blood was genotyped for West African ancestry markers and vitamin D–related SNPs.

RESULTS. Serum concentrations of 25(OH)D were lower in AAs, but concentrations of 1,25(OH)₂D in the prostate tissue were higher compared with EAs. Expression of the vitamin D receptor was higher in prostate tissue from AAs. Expression of the extracellular receptor of vitamin D binding protein, LRP2, was positively associated with West African ancestry and inversely associated with tissue 25(OH)D concentrations in AAs.

CONCLUSIONS. The relationships between vitamin D binding protein LRP2 and vitamin D metabolites suggest that the prohormone is actively transported into the prostate, followed by intraprostatic conversion to the active hormone, rather than passive diffusion. These findings support the presence of a compensatory response in prostate tissue to vitamin D deficiency in AAs and reveal a previously unknown complexity involving tissue distribution of vitamin D metabolites.

FUNDING. Department of Defense Prostate Cancer Research Program Idea Award for Disparities Research PC121923 (LN and RK) and the NIH 1R01MD007105 (RK).

Authors

Zachary Richards, Ken Batai, Rachael Farhat, Ebony Shah, Andrew Makowski, Peter H. Gann, Rick Kittles, Larisa Nonn

Metastasis regulation by PPARD expression in cancer cells

• Text
• PDF

Abstract

Peroxisome proliferator–activated receptor–δ (PPARD) is upregulated in many major human cancers, but the role that its expression in cancer cells has in metastasis remains poorly understood. Here, we show that specific PPARD downregulation or genetic deletion of PPARD in cancer cells significantly repressed metastasis in various cancer models in vivo. Mechanistically, PPARD promoted angiogenesis via interleukin 8 in vivo and in vitro. Analysis of transcriptome profiling of HCT116 colon cancer cells with or without genetic deletion of PPARD and gene expression patterns in The Cancer Genome Atlas colorectal adenocarcinoma database identified novel pro-metastatic genes (GJA1, VIM, SPARC, STC1, SNCG) as PPARD targets. PPARD expression in cancer cells drastically affected epithelial-mesenchymal transition, migration, and invasion, further underscoring its necessity for metastasis. Clinically, high PPARD expression in various major human cancers (e.g., colorectal, lung, breast) was associated with significantly reduced metastasis-free survival. Our results demonstrate that PPARD, a druggable protein, is an important molecular target in metastatic cancer.

Authors

Xiangsheng Zuo, Weiguo Xu, Min Xu, Rui Tian, Micheline J. Moussalli, Fei Mao, Xiaofeng Zheng, Jing Wang, Jeffrey S. Morris, Mihai Gagea, Cathy Eng, Scott Kopetz, Dipen M. Maru, Asif Rashid, Russell Broaddus, Daoyan Wei, Mien-Chie Hung, Anil K. Sood, Imad Shureiqi

Anti-SIRPα antibodies as a potential new tool for cancer immunotherapy

• Text
• PDF

Abstract

Tumor cells are thought to evade immune surveillance through interaction with immune cells. Much recent attention has focused on the modification of immune responses as a basis for new cancer treatments. SIRPα is an Ig superfamily protein that inhibits phagocytosis in macrophages upon interaction with its ligand CD47 expressed on the surface of target cells. Here, we show that SIRPα is highly expressed in human renal cell carcinoma and melanoma. Furthermore, an anti-SIRPα Ab that blocks the interaction with CD47 markedly suppressed tumor formation by renal cell carcinoma or melanoma cells in immunocompetent syngeneic mice. This inhibitory effect of the Ab appeared to be mediated by dual mechanisms: direct induction of Ab-dependent cellular phagocytosis of tumor cells by macrophages and blockade of CD47-SIRPα signaling that negatively regulates such phagocytosis. The antitumor effect of the Ab was greatly attenuated by selective depletion not only of macrophages but also of NK cells or CD8⁺ T cells. In addition, the anti-SIRPα Ab also enhances the inhibitory effects of Abs against CD20 and programmed cell death 1 (PD-1) on tumor formation in mice injected with SIRPα-nonexpressing tumor cells. Anti-SIRPα Abs thus warrant further study as a potential new therapy for a broad range of cancers.

Authors

Tadahiko Yanagita, Yoji Murata, Daisuke Tanaka, Sei-ichiro Motegi, Eri Arai, Edwin Widyanto Daniwijaya, Daisuke Hazama, Ken Washio, Yasuyuki Saito, Takenori Kotani, Hiroshi Ohnishi, Per-Arne Oldenborg, Noel Verjan Garcia, Masayuki Miyasaka, Osamu Ishikawa, Yae Kanai, Takahide Komori, Takashi Matozaki

A patient-derived-xenograft platform to study BRCA-deficient ovarian cancers

• Text
• PDF

Abstract

Approximately 50% of high-grade serous ovarian cancers (HGSOCs) have defects in genes involved in homologous recombination (HR) (i.e., BRCA1/2). Preclinical models to optimize therapeutic strategies for HR-deficient (HRD) HGSOC are lacking. We developed a preclinical platform for HRD HGSOCs that includes primary tumor cultures, patient-derived xenografts (PDXs), and molecular imaging. Models were characterized by immunohistochemistry, targeted sequencing, and reverse-phase protein array analysis. We also tested PDX tumor response to PARP, CHK1, and ATR inhibitors. Fourteen orthotopic HGSOC PDX models with BRCA mutations (BRCA^MUT) were established with a 93% success rate. The orthotopic PDX model emulates the natural progression of HGSOC, including development of a primary ovarian tumor and metastasis to abdominal viscera. PDX response to standard chemotherapy correlated to that demonstrated in the patient. Pathogenic mutations and HGSOC markers were preserved after multiple mouse passages, indicating retention of underlying molecular mechanisms of carcinogenesis. A BRCA2^MUT PDX with high p-CHK1 demonstrated a similar delay of tumor growth in response to PARP, CHK1, and ATR inhibitors. A poly (ADP-ribose) polymerase (PARP) inhibitor radiotracer correlated with PARP1 activity and showed response to PARP inhibition in the BRCA2^MUT PDX model. In summary, the orthotopic HGSOC PDX represents a robust and reliable model to optimize therapeutic strategies for BRCA^MUT HGSOC.

Authors

Erin George, Hyoung Kim, Clemens Krepler, Brandon Wenz, Mehran Makvandi, Janos L. Tanyi, Eric Brown, Rugang Zhang, Patricia Brafford, Stephanie Jean, Robert H. Mach, Yiling Lu, Gordon B. Mills, Meenhard Herlyn, Mark Morgan, Xiaochen Zhang, Robert Soslow, Ronny Drapkin, Neil Johnson, Ying Zheng, George Cotsarelis, Katherine L. Nathanson, Fiona Simpkins