1
|
Krisanits BA, Schuster R, Randise J, Nogueira LM, Lane JT, Panguluri GA, Li H, Helke K, Cuitiño MC, Koivisto C, Spruill L, Ostrowski MC, Anderson SM, Turner DP, Findlay VJ. Pubertal exposure to dietary advanced glycation end products disrupts ductal morphogenesis and induces atypical hyperplasia in the mammary gland. Breast Cancer Res 2023; 25:118. [PMID: 37803429 PMCID: PMC10559657 DOI: 10.1186/s13058-023-01714-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 09/18/2023] [Indexed: 10/08/2023] Open
Abstract
BACKGROUND Advanced glycation end products (AGEs) are reactive metabolites intrinsically linked with modern dietary patterns. Processed foods, and those high in sugar, protein and fat, often contain high levels of AGEs. Increased AGE levels are associated with increased breast cancer risk, however their significance has been largely overlooked due to a lack of direct cause-and-effect relationship. METHODS To address this knowledge gap, FVB/n mice were fed regular, low AGE, and high AGE diets from 3 weeks of age and mammary glands harvested during puberty (7 weeks) or adulthood (12 weeks and 7 months) to determine the effects upon mammary gland development. At endpoint mammary glands were harvested and assessed histologically (n ≥ 4). Immunohistochemistry and immunofluorescence were used to assess cellular proliferation and stromal fibroblast and macrophage recruitment. The Kruskal-Wallis test were used to compare continuous outcomes among groups. Mammary epithelial cell migration and invasion in response to AGE-mediated fibroblast activation was determined in two-compartment co-culture models. In vitro experiments were performed in triplicate. The nonparametric Wilcoxon rank sum test was used to compare differences between groups. RESULTS Histological analysis revealed the high AGE diet delayed ductal elongation, increased primary branching, as well as increased terminal end bud number and size. The high AGE diet also led to increased recruitment and proliferation of stromal cells to abnormal structures that persisted into adulthood. Atypical hyperplasia was observed in the high AGE fed mice. Ex vivo fibroblasts from mice fed dietary-AGEs retain an activated phenotype and promoted epithelial migration and invasion of non-transformed immortalized and tumor-derived mammary epithelial cells. Mechanistically, we found that the receptor for AGE (RAGE) is required for AGE-mediated increases in epithelial cell migration and invasion. CONCLUSIONS We observed a disruption in mammary gland development when mice were fed a diet high in AGEs. Further, both epithelial and stromal cell populations were impacted by the high AGE diet in the mammary gland. Educational, interventional, and pharmacological strategies to reduce AGEs associated with diet may be viewed as novel disease preventive and/or therapeutic initiatives during puberty.
Collapse
Affiliation(s)
- Bradley A Krisanits
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Reid Schuster
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Jaime Randise
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Lourdes M Nogueira
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Jackson T Lane
- Department of Surgery and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA
| | - Gowtami A Panguluri
- Department of Surgery and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA
| | - Hong Li
- Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC, USA
- Department of Public Health Sciences, University of California, Davis, CA, USA
| | - Kristi Helke
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA
- Department of Comparative Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Maria C Cuitiño
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
- College of Health Sciences, Comprehensive Cancer Center, Ohio State University, Columbus, OH, USA
| | - Christopher Koivisto
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Laura Spruill
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Michael C Ostrowski
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Steven M Anderson
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - David P Turner
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA.
- Department of Surgery and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA.
| | - Victoria J Findlay
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA.
- Department of Surgery and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA.
| |
Collapse
|
2
|
Lefler JE, MarElia-Bennett CB, Thies KA, Hildreth BE, Sharma SM, Pitarresi JR, Han L, Everett C, Koivisto C, Cuitino MC, Timmers CD, O'Quinn E, Parrish M, Romeo MJ, Linke AJ, Hobbs GA, Leone G, Guttridge DC, Zimmers TA, Lesinski GB, Ostrowski MC. STAT3 in tumor fibroblasts promotes an immunosuppressive microenvironment in pancreatic cancer. Life Sci Alliance 2022; 5:e202201460. [PMID: 35803738 PMCID: PMC9270499 DOI: 10.26508/lsa.202201460] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 06/30/2022] [Accepted: 06/30/2022] [Indexed: 01/21/2023] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is associated with an incredibly dense stroma, which contributes to its recalcitrance to therapy. Cancer-associated fibroblasts (CAFs) are one of the most abundant cell types within the PDAC stroma and have context-dependent regulation of tumor progression in the tumor microenvironment (TME). Therefore, understanding tumor-promoting pathways in CAFs is essential for developing better stromal targeting therapies. Here, we show that disruption of the STAT3 signaling axis via genetic ablation of Stat3 in stromal fibroblasts in a Kras G12D PDAC mouse model not only slows tumor progression and increases survival, but re-shapes the characteristic immune-suppressive TME by decreasing M2 macrophages (F480+CD206+) and increasing CD8+ T cells. Mechanistically, we show that loss of the tumor suppressor PTEN in pancreatic CAFs leads to an increase in STAT3 phosphorylation. In addition, increased STAT3 phosphorylation in pancreatic CAFs promotes secretion of CXCL1. Inhibition of CXCL1 signaling inhibits M2 polarization in vitro. The results provide a potential mechanism by which CAFs promote an immune-suppressive TME and promote tumor progression in a spontaneous model of PDAC.
Collapse
Affiliation(s)
- Julia E Lefler
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Catherine B MarElia-Bennett
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Katie A Thies
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Blake E Hildreth
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Sudarshana M Sharma
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Jason R Pitarresi
- Division of Gastroenterology, Department of Medicine and Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA, USA
| | - Lu Han
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Caroline Everett
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Christopher Koivisto
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Maria C Cuitino
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Cynthia D Timmers
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Elizabeth O'Quinn
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Melodie Parrish
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Martin J Romeo
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Amanda J Linke
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - G Aaron Hobbs
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Gustavo Leone
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Denis C Guttridge
- Department of Pediatrics and Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA
| | - Teresa A Zimmers
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Gregory B Lesinski
- Department of Hematology and Medical Oncology, Winship Cancer Institute of Emory University, Atlanta, GA, USA
| | - Michael C Ostrowski
- Hollings Cancer Center and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| |
Collapse
|
3
|
Ochoa-Rios S, O'Connor IP, Kent LN, Clouse JM, Hadjiyannis Y, Koivisto C, Pecot T, Angel PM, Drake RR, Leone G, Mehta AS, Rockey DC. Imaging Mass Spectrometry Reveals Alterations in N-Linked Glycosylation That Are Associated With Histopathological Changes in Nonalcoholic Steatohepatitis in Mouse and Human. Mol Cell Proteomics 2022; 21:100225. [PMID: 35331917 PMCID: PMC9092512 DOI: 10.1016/j.mcpro.2022.100225] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 03/14/2022] [Accepted: 03/17/2022] [Indexed: 01/20/2023] Open
Abstract
Nonalcoholic steatohepatitis (NASH) is the progressive form of nonalcoholic fatty liver disease (NAFLD) and is characterized by inflammation, hepatocyte injury, and fibrosis. Further, NASH is a risk factor for cirrhosis and hepatocellular carcinoma. Previous research demonstrated that serum N-glycan profiles can be altered in NASH patients. Here, we hypothesized that these N-glycan modifications may be associated with specific liver damage in NAFLD and NASH. To investigate the N-glycome profile in tissue, imaging mass spectrometry was used for a qualitative and quantitative in situ N-linked glycan analysis of mouse and human NAFLD/NASH tissue. A murine model was used to induce NAFLD and NASH through ad libitum feeding with either a high-fat diet or a Western diet, respectively. Mice fed a high-fat diet or Western diet developed inflammation, steatosis, and fibrosis, consistent with NAFLD/NASH phenotypes. Induction of NAFLD/NASH for 18 months using high caloric diets resulted in increased expression of mannose, complex/fucosylated, and hybrid N-glycan structures compared to control mouse livers. To validate the animal results, liver biopsy specimens from 51 human NAFLD/NASH patients representing the full range of NASH Clinical Research Network fibrosis stages were analyzed. Importantly, the same glycan alterations observed in mouse models were observed in human NASH biopsies and correlated with the degree of fibrosis. In addition, spatial glycan alterations were localized specifically to histopathological changes in tissue like fibrotic and fatty areas. We demonstrate that the use of standard staining's combined with imaging mass spectrometry provide a full profile of the origin of N-glycan modifications within the tissue. These results indicate that the spatial distribution of abundances of released N-glycans correlate with regions of tissue steatosis associated with NAFLD/NASH.
Collapse
Affiliation(s)
- Shaaron Ochoa-Rios
- Department of Cell and Molecular Pharmacology, Medical University of South Carolina, Charleston, South Carolina, USA.
| | - Ian P O'Connor
- Digestive Disease Research Center, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Lindsey N Kent
- Department of Obstetrics and Gynecology, Washington University in St Louis Center for Reproductive Health Sciences, St Louis, Missouri, USA
| | - Julian M Clouse
- Department of Cancer Biology and Genetics, The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA
| | - Yannis Hadjiyannis
- Department of Cancer Biology and Genetics, The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA
| | - Christopher Koivisto
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
| | | | - Peggi M Angel
- Department of Cell and Molecular Pharmacology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Richard R Drake
- Department of Cell and Molecular Pharmacology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Gustavo Leone
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA; Department of Biochemistry, Medical College of Wisconsin, MCW Cancer Center, Milwaukee, Wisconsin, USA
| | - Anand S Mehta
- Department of Cell and Molecular Pharmacology, Medical University of South Carolina, Charleston, South Carolina, USA.
| | - Don C Rockey
- Digestive Disease Research Center, Medical University of South Carolina, Charleston, South Carolina, USA
| |
Collapse
|
4
|
Yoshida A, Phillips-Mason P, Tarallo V, Avril S, Koivisto C, Leone G, Diehl JA. Non-phosphorylatable cyclin D1 mutant potentiates endometrial hyperplasia and drives carcinoma with Pten loss. Oncogene 2022; 41:2187-2195. [PMID: 35210557 PMCID: PMC10056880 DOI: 10.1038/s41388-022-02243-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/25/2022] [Accepted: 02/10/2022] [Indexed: 11/08/2022]
Abstract
Cyclin D1 is a regulatory subunit of -Cyclin Dependent Kinases 4 and 6 (CDK4/6) and regulates progression from G1 to S phase of the cell cycle. Dysregulated cyclin D1-CDK4/6 contributes to abnormal cell proliferation and tumor development. Phosphorylation of threonine 286 of cyclin D1 is necessary for ubiquitin-dependent degradation. Non-phosphorylatable cyclin D1 mutants are stabilized and concentrated in the nucleus, contributing to genomic instability and tumor development. Studies investigating the tumor-promoting functions of cyclin D1 mutants have focused on the use of artificial promoters to drive the expression which unfortunately may not accurately reflect tumorigenic functions of mutant cyclin D1 in cancer development. We have generated a conditional knock-in mouse model where cyclin D1T286A is expressed under the control of its endogenous promoter following Cre-dependent excision of a lox-stop-lox sequence. Acute expression of cyclin D1T286A following tamoxifen-inducible Cre recombinase triggers inflammation, lymphocyte abnormality and ultimately mesenteric tumors in the intestine. Tissue-specific expression of cyclin D1T286A in the uterus and endometrium cooperates with Pten loss to drive endometrial hyperplasia and cancer. Mechanistically, cyclin D1T286A mutant activates NF-κB signaling, augments inflammation, and contributes to tumor development. These results indicate that mutation of cyclin D1 at threonine 286 has a critical role in regulating inflammation and tumor development.
Collapse
Affiliation(s)
- Akihiro Yoshida
- Department of Dermatology, University Hospitals Cleveland Medical Center and Case Western Reserve University, Cleveland, OH, 44106, USA.
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, 44106, USA.
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, 44106, USA.
| | - Polly Phillips-Mason
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Vincenzo Tarallo
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Stefanie Avril
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, 44106, USA
- Department of Pathology, University Hospitals Cleveland Medical Center and Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Christopher Koivisto
- Department of Biochemistry, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Gustavo Leone
- Medical College of Wisconsin Cancer Center, Department of Biochemistry, Medical College of Wisconsin, Wauwatosa, WI, 53226, USA
| | - J Alan Diehl
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, 44106, USA.
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, 44106, USA.
| |
Collapse
|
5
|
Iwanowycz S, Ngoi S, Li Y, Hill M, Koivisto C, Parrish M, Guo B, Li Z, Liu B. Type-2 dendritic cells mediate control of cytotoxic T cell-resistant tumors. JCI Insight 2021; 6:e145885. [PMID: 34283809 PMCID: PMC8492342 DOI: 10.1172/jci.insight.145885] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 07/15/2021] [Indexed: 11/17/2022] Open
Abstract
Type 2 DCs (DC2s) comprise the majority of conventional DCs within most tumors; however, little is known about their ability to initiate and sustain antitumor immunity, as most studies have focused on antigen cross-presenting DC1s. Here, we report that DC2 infiltration identified by analysis of multiple human cancer data sets showed a significant correlation with survival across multiple human cancers, with the benefit being seen in tumors resistant to cytotoxic T cell control. Characterization of DC subtype infiltration into an immunotherapy-resistant model of breast cancer revealed that impairment of DC1s through 2 unique models resulted in enhanced DC2 functionality and improved tumor control. BATF3 deficiency depleted intratumoral DC1s, which led to increased DC2 lymph node migration and CD4+ T cell activation. Enhancing DC2 stimulatory potential by genetic deletion of Hsp90b1 (encoding molecular chaperon GP96) led to a similar enhancement of T cell immunity and improved survival in a spontaneous breast cancer model. These data highlight the therapeutic and prognostic potential of DC2s within checkpoint blockade–resistant tumors.
Collapse
Affiliation(s)
- Stephen Iwanowycz
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, United States of America
| | - Soo Ngoi
- Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, United States of America
| | - Yingqi Li
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, United States of America
| | - Megan Hill
- Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, United States of America
| | - Christopher Koivisto
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, United States of America
| | - Melodie Parrish
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, United States of America
| | - Beichu Guo
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, United States of America
| | - Zihai Li
- The Pelotonia Institute for Immuno-Oncology, The Ohio State University College of Medicine, Columbus, United States of America
| | - Bei Liu
- Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, United States of America
| |
Collapse
|
6
|
Park D, Shakya R, Koivisto C, Pitarresi JR, Szabolcs M, Kladney R, Hadjis A, Mace TA, Ludwig T. Murine models for familial pancreatic cancer: Histopathology, latency and drug sensitivity among cancers of Palb2, Brca1 and Brca2 mutant mouse strains. PLoS One 2019; 14:e0226714. [PMID: 31877165 PMCID: PMC6932818 DOI: 10.1371/journal.pone.0226714] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 12/03/2019] [Indexed: 12/14/2022] Open
Abstract
Alterations of the PALB2 tumor suppressor gene have been identified in familial breast, ovarian and pancreatic cancer cases. PALB2 cooperates with BRCA1/2 proteins through physical interaction in initiation of homologous recombination, in maintenance of genome integrity following DNA double-strand breaks. To determine if the role of PALB2 as a linker between BRCA1 and BRCA2 is critical for BRCA1/2-mediated tumor suppression, we generated Palb2 mouse pancreatic cancer models and compared tumor latencies, phenotypes and drug responses with previously generated Brca1/2 pancreatic cancer models. For development of Palb2 pancreatic cancer, we crossed conditional Palb2 null mouse with mice carrying the KrasG12D; p53R270H; Pdx1-Cre (KPC) constructs, and these animals were observed for pancreatic tumor development. Individual deletion of Palb2, Brca1 or Brca2 genes in pancreas per se using Pdx1-Cre was insufficient to cause tumors, but it reduced pancreata size. Concurrent expression of mutant KrasG12D and p53R270H, with tumor suppressor inactivated strains in Palb2-KPC, Brca1-KPC or Brca2-KPC, accelerated pancreatic ductal adenocarcinoma (PDAC) development. Moreover, most Brca1-KPC and some Palb2-KPC animals developed mucinous cystic neoplasms with PDAC, while Brca2-KPC and KPC animals did not. 26% of Palb2-KPC mice developed MCNs in pancreata, which resemble closely the Brca1 deficient tumors. However, the remaining 74% of Palb2-KPC animals developed PDACs without any cysts like Brca2 deficient tumors. In addition, the number of ADM lesions and immune cells infiltrations (CD3+ and F/480+) were significantly increased in Brca1-KPC tumors, but not in Brca2-KPC tumors. Interestingly, the level of ADM lesions and infiltration of CD3+ or F/480+ cells in Palb2-KPC tumors were intermediate between Brca1-KPC and Brca2-KPC tumors. As expected, disruption of Palb2 and Brca1/2 sensitized tumor cells to DNA damaging agents in vitro and in vivo. Altogether, Palb2-KPC PDAC exhibited features observed in both Brca1-KPC and Brca2-KPC tumors, which could be due to its role, as a linker between Brca1 and Brca2.
Collapse
Affiliation(s)
- Dongju Park
- Department of Cancer Biology and Genetics, The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America
| | - Reena Shakya
- The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America
| | - Christopher Koivisto
- Department of Cancer Biology and Genetics, The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America
| | - Jason R Pitarresi
- Department of Cancer Biology and Genetics, The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America
| | - Matthias Szabolcs
- Institute for Cancer Genetics, Department of Pathology and Cell Biology, and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York, United States of America
| | - Raleigh Kladney
- Department of Cancer Biology and Genetics, The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America
| | - Ashley Hadjis
- Department of Cancer Biology and Genetics, The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America
| | - Thomas A Mace
- Department of Internal Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Thomas Ludwig
- Department of Cancer Biology and Genetics, The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America
| |
Collapse
|
7
|
Thies K, Hammer A, Hildreth B, Russell L, Sizemore S, Trimboli A, Kladney R, Steck S, Das M, Bolyard C, Pilarski R, Cuitino M, Koivisto C, Schoenfield L, Otero J, Chakravarti A, Ringel M, Li Z, Kaur B, Leone G, Ostrowski M, Sizemore G. BSCI-11. STROMAL PLATELET DERIVED GROWTH FACTOR RECEPTOR-β (PDGFRβ) PROMOTES BREAST CANCER BRAIN METASTASIS. Neurooncol Adv 2019. [PMCID: PMC7213233 DOI: 10.1093/noajnl/vdz014.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Stromal platelet-derived growth factor receptor-beta (PDGFRβ) has emerged as an actionable mediator of breast tumor-stromal communication. As a receptor tyrosine kinase, PDGFRβ is activated by its ligand, PDGFB, which is released by neighboring tumor epithelium and endothelium. However, how PDGF signaling mediates breast cancer (BC) initiation, progression, and metastasis remains unclear. To evaluate PDGFRβ in this disease, we developed a mouse model of stromal-specific PDGFRβ activation using the Fsp-cre transgene previously published by our group. Mesenchymal-specific activation of PDGFRβ promotes preferential experimental brain metastasis of PDGFB-expressing mammary tumor cells when injected intravenously and accelerates intracranial tumor growth of these cells. Mammary tumor cells expressing low levels of PDGFB do not exhibit a similar increase in brain metastases in PDGFRβ mutant mice. To our knowledge, this is the first example where genetic manipulation of the stroma leads to an increased incidence of BCBM. Our pre-clinical data suggests that primary breast tumors that express high PDGFB could preferentially metastasize to the brain. To test this in patients, we analyzed PDGFB protein expression in a tissue microarray comprised of HER2-positive and triple negative BC primary tumors. While high PDGFB did not correlate with site-independent metastatic recurrence, it was prognostic of brain metastasis, mirroring our mouse data. Our findings suggest that high primary tumor PDGFB expression defines a subset of BC patients predisposed to brain metastases. These patients may benefit from therapeutic intervention of PDGFRβ signaling. To test this pre-clinically, we treated mice harboring intracranial tumors with the PDGFR-specific inhibitor, crenolanib. Excitingly, crenolanib treatment significantly inhibited the brain tumor burden in these mice. Combined, our findings (1) advocate that primary tumor expression of PDGFB is a novel prognostic biomarker for the development of BCBM and (2) support clinical trial evaluation of PDGFR inhibitors for the prevention and treatment of BCBM.
Collapse
Affiliation(s)
| | | | - Blake Hildreth
- Medical University of South Carolina, Charleston, SC, USA
| | | | | | | | | | | | | | | | | | - Maria Cuitino
- Medical University of South Carolina, Charleston, SC, USA
| | | | | | - Jose Otero
- Ohio State University, Columbus, OH, USA
| | | | | | - Zaibo Li
- Ohio State University, Columbus, OH, USA
| | | | - Gustavo Leone
- Medical University of South Carolina, Charleston, SC, USA
| | | | | |
Collapse
|
8
|
Basree MM, Shinde N, Koivisto C, Cuitino M, Kladney R, Zhang J, Stephens J, Palettas M, Zhang A, Kim HK, Acero-Bedoya S, Trimboli A, Stover DG, Ludwig T, Ganju R, Weng D, Shields P, Freudenheim J, Leone GW, Sizemore GM, Majumder S, Ramaswamy B. Abrupt involution induces inflammation, estrogenic signaling, and hyperplasia linking lack of breastfeeding with increased risk of breast cancer. Breast Cancer Res 2019; 21:80. [PMID: 31315645 PMCID: PMC6637535 DOI: 10.1186/s13058-019-1163-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 06/21/2019] [Indexed: 12/12/2022] Open
Abstract
Background A large collaborative analysis of data from 47 epidemiological studies concluded that longer duration of breastfeeding reduces the risk of developing breast cancer. Despite the strong epidemiological evidence, the molecular mechanisms linking prolonged breastfeeding to decreased risk of breast cancer remain poorly understood. Methods We modeled two types of breastfeeding behaviors in wild type FVB/N mice: (1) normal or gradual involution of breast tissue following prolonged breastfeeding and (2) forced or abrupt involution following short-term breastfeeding. To accomplish this, pups were gradually weaned between 28 and 31 days (gradual involution) or abruptly at 7 days postpartum (abrupt involution). Mammary glands were examined for histological changes, proliferation, and inflammatory markers by immunohistochemistry. Fluorescence-activated cell sorting was used to quantify mammary epithelial subpopulations. Gene set enrichment analysis was used to analyze gene expression data from mouse mammary luminal progenitor cells. Similar analysis was done using gene expression data generated from human breast samples obtained from parous women enrolled on a tissue collection study, OSU-2011C0094, and were undergoing reduction mammoplasty without history of breast cancer. Results Mammary glands from mice that underwent abrupt involution exhibited denser stroma, altered collagen composition, higher inflammation and proliferation, increased estrogen receptor α and progesterone receptor expression compared to those that underwent gradual involution. Importantly, when aged to 4 months postpartum, mice that were in the abrupt involution cohort developed ductal hyperplasia and squamous metaplasia. Abrupt involution also resulted in a significant expansion of the luminal progenitor cell compartment associated with enrichment of Notch and estrogen signaling pathway genes. Breast tissues obtained from healthy women who breastfed for < 6 months vs ≥ 6 months showed significant enrichment of Notch signaling pathway genes, along with a trend for enrichment for luminal progenitor gene signature similar to what is observed in BRCA1 mutation carriers and basal-like breast tumors. Conclusions We report here for the first time that forced or abrupt involution of the mammary glands following pregnancy and lack of breastfeeding results in expansion of luminal progenitor cells, higher inflammation, proliferation, and ductal hyperplasia, a known risk factor for developing breast cancer. Electronic supplementary material The online version of this article (10.1186/s13058-019-1163-7) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Mustafa M Basree
- The Comprehensive Cancer Center, College of Medicine, The Ohio State University, 460 West 12th Avenue, Columbus, OH, 43210, USA
| | - Neelam Shinde
- The Comprehensive Cancer Center, College of Medicine, The Ohio State University, 460 West 12th Avenue, Columbus, OH, 43210, USA
| | - Christopher Koivisto
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA.,Department of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Maria Cuitino
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA.,Department of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Raleigh Kladney
- The Comprehensive Cancer Center, College of Medicine, The Ohio State University, 460 West 12th Avenue, Columbus, OH, 43210, USA
| | - Jianying Zhang
- Department of Biomedical Informatics' Center for Biostatistics, The Ohio State University, Columbus, OH, USA
| | - Julie Stephens
- Department of Biomedical Informatics' Center for Biostatistics, The Ohio State University, Columbus, OH, USA
| | - Marilly Palettas
- Department of Biomedical Informatics' Center for Biostatistics, The Ohio State University, Columbus, OH, USA
| | - Allen Zhang
- The Comprehensive Cancer Center, College of Medicine, The Ohio State University, 460 West 12th Avenue, Columbus, OH, 43210, USA
| | - Hee Kyung Kim
- The Comprehensive Cancer Center, College of Medicine, The Ohio State University, 460 West 12th Avenue, Columbus, OH, 43210, USA
| | - Santiago Acero-Bedoya
- The Comprehensive Cancer Center, College of Medicine, The Ohio State University, 460 West 12th Avenue, Columbus, OH, 43210, USA
| | - Anthony Trimboli
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA.,Department of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Daniel G Stover
- The Comprehensive Cancer Center, College of Medicine, The Ohio State University, 460 West 12th Avenue, Columbus, OH, 43210, USA.,Department of Internal Medicine, College of Medicine, The Ohio State University, 320 West 10th Avenue, Columbus, OH, 43210, USA
| | - Thomas Ludwig
- The Comprehensive Cancer Center, College of Medicine, The Ohio State University, 460 West 12th Avenue, Columbus, OH, 43210, USA
| | - Ramesh Ganju
- The Comprehensive Cancer Center, College of Medicine, The Ohio State University, 460 West 12th Avenue, Columbus, OH, 43210, USA.,Department of Pathology, The Ohio State University, Columbus, OH, USA
| | - Daniel Weng
- The Comprehensive Cancer Center, College of Medicine, The Ohio State University, 460 West 12th Avenue, Columbus, OH, 43210, USA.,Department of Internal Medicine, College of Medicine, The Ohio State University, 320 West 10th Avenue, Columbus, OH, 43210, USA
| | - Peter Shields
- The Comprehensive Cancer Center, College of Medicine, The Ohio State University, 460 West 12th Avenue, Columbus, OH, 43210, USA.,Department of Internal Medicine, College of Medicine, The Ohio State University, 320 West 10th Avenue, Columbus, OH, 43210, USA
| | - Jo Freudenheim
- Department of Epidemiology and Environmental Health, University at Buffalo, Buffalo, USA
| | - Gustavo W Leone
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA.,Department of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Gina M Sizemore
- The Comprehensive Cancer Center, College of Medicine, The Ohio State University, 460 West 12th Avenue, Columbus, OH, 43210, USA.,Department of Radiation Oncology, The Ohio State University, Columbus, OH, USA
| | - Sarmila Majumder
- The Comprehensive Cancer Center, College of Medicine, The Ohio State University, 460 West 12th Avenue, Columbus, OH, 43210, USA.
| | - Bhuvaneswari Ramaswamy
- The Comprehensive Cancer Center, College of Medicine, The Ohio State University, 460 West 12th Avenue, Columbus, OH, 43210, USA. .,Department of Internal Medicine, College of Medicine, The Ohio State University, 320 West 10th Avenue, Columbus, OH, 43210, USA.
| |
Collapse
|
9
|
Basree MM, Shinde N, Koivisto C, Cuitino M, Kladney R, Zhang A, Kim HK, Trimboli A, Zhang J, Leone GW, Sizemore GM, Majumder S, Ramaswamy B. Abstract 2242: Breastfeeding protects against pro-tumorigenic changes in the mammary gland by limiting epithelial luminal progenitor cell expansion. Cancer Res 2018. [DOI: 10.1158/1538-7445.am2018-2242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction: Multiple epidemiological studies have shown that prolonged breastfeeding is associated with a reduced risk of developing triple-negative/basal-like breast cancers (TN/BLBC). However, no preclinical models that delineate the mechanism of this link exist. This understanding is critical not only to prevent TN/BLBC, but also to address disparity in breast cancer outcomes, as African-American women have a higher incidence of TN/BLBC and lower prevalence of breastfeeding. We present our data using mouse models that provides new insights into this link.
Experimental procedure: We modeled gradual involution (GI) and abrupt involution (AI) of mammary glands (MGs) in wild type FVB/N mice. Uniparous mice were assigned to AI or GI cohorts either by removal of all pups on day7 postpartum (AI) or allowing the pups to naturally wean (GI). MGs were harvested for analysis on postpartum day28, day56 and day120. We assessed MG morphology/histology using whole mounts and H&E stained sections, collagen deposition using Trichrome and PicroSirus red staining, inflammatory markers and immune cell infiltration using immunohistochemistry. Mammary epithelial cell hierarchy was analyzed by Fluorescence-Activated Cell Sorting of a single cell suspension prepared from the MGs. Gene expression was analyzed in mouse mammary epithelial cells using Affymatrix Gene ChIP Mouse Transcriptome array 1.0 and Gene Set Enrichment Analysis (GSEA) was used to analyze gene expression data.
Summary: Abruptly involuted MGs exhibited altered morphology including denser stroma, increased collagen deposition with higher levels of Type I collagen, increased inflammation (pStat3-Y705), increased immune cell infiltration and proliferation compared to GI glands. The mammary epithelial cell hierarchy was disrupted with marked expansion of the luminal progenitor (LP) population in the AI glands but not in the GI glands, a trend frequently observed in women heterozygous for BRCA1 mutation at higher risk of developing BLBC. Enrichment of an LP gene signature and Notch pathway was observed in mouse LP cells isolated from the AI glands. Most strikingly, the AI glands developed alveolar hyperplasia, and squamous metaplasia within 4 months of removal of the pups.
Conclusion: Involution leading to a pro-inflammatory milieu in the MG is well established. Whether involution that happens gradually after prolonged breastfeeding differs in its effect on MGs has not been well studied. Using novel animal modeling to study the differences in MGs following abrupt vs gradual involution, we report a distinct morphology in the mammary tissue favoring pro-carcinogenic changes following AI. Furthermore, we show for the first time, expansion of the LP population in AI glands, which is known to be cell of origin for TN/BLBC potentially linking the risk of TN/BLBC with lack of breastfeeding. Further studies are ongoing.
Citation Format: Mustafa M. Basree, Neelam Shinde, Christopher Koivisto, Maria Cuitino, Raleigh Kladney, Allen Zhang, Hee Kyung Kim, Anthony Trimboli, Jianying Zhang, Gustavo W. Leone, Gina M. Sizemore, Sarmila Majumder, Bhuvaneswari Ramaswamy. Breastfeeding protects against pro-tumorigenic changes in the mammary gland by limiting epithelial luminal progenitor cell expansion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2242.
Collapse
Affiliation(s)
| | - Neelam Shinde
- 2The Ohio State University Wexner Medical Center, Columbus, OH
| | | | - Maria Cuitino
- 3Medical University of South Carolina Hollings Cancer Center, Charleston, SC
| | - Raleigh Kladney
- 4The Ohio State University Comprehensive Cancer Center, Columbus, OH
| | - Allen Zhang
- 2The Ohio State University Wexner Medical Center, Columbus, OH
| | - Hee Kyung Kim
- 2The Ohio State University Wexner Medical Center, Columbus, OH
| | - Anthony Trimboli
- 3Medical University of South Carolina Hollings Cancer Center, Charleston, SC
| | - Jianying Zhang
- 5The Ohio State University Center of Biostatistics, Columbus, OH
| | - Gustavo W. Leone
- 3Medical University of South Carolina Hollings Cancer Center, Charleston, SC
| | - Gina M. Sizemore
- 4The Ohio State University Comprehensive Cancer Center, Columbus, OH
| | | | | |
Collapse
|
10
|
Abstract
A 4 yr old border collie presenting for mydriasis and decreased mentation and a 7 yr old Boston terrier presenting for obtundation, head tilt, and paraparesis were both evaluated using MRI. Findings in both included mass lesions of the thalamus and brainstem that were hypo- to isointense on T1-weighted images and hyperintense on T2-weighted images with regions of hypointensity, and robust contrast enhancement and displacement of adjacent structures. Postmortem histopathology findings, tumor location, and a mixed pattern of epithelial cell differentiation were consistent with germ cell tumor in both cases. Germ cell tumor of the suprasellar region is an infrequently reported neoplasm of dogs and imaging findings in this species have not been well described in the prior literature.
Collapse
Affiliation(s)
- Laurie Cook
- From the Department of Veterinary Clinical Sciences (L.C., M.T., W.T.D.) and Department of Veterinary Biosciences (C.K., M.O.), The Ohio State University, Columbus, Ohio
| | - Michelle Tensley
- From the Department of Veterinary Clinical Sciences (L.C., M.T., W.T.D.) and Department of Veterinary Biosciences (C.K., M.O.), The Ohio State University, Columbus, Ohio
| | - Wm Tod Drost
- From the Department of Veterinary Clinical Sciences (L.C., M.T., W.T.D.) and Department of Veterinary Biosciences (C.K., M.O.), The Ohio State University, Columbus, Ohio
| | - Christopher Koivisto
- From the Department of Veterinary Clinical Sciences (L.C., M.T., W.T.D.) and Department of Veterinary Biosciences (C.K., M.O.), The Ohio State University, Columbus, Ohio
| | - Michael Oglesbee
- From the Department of Veterinary Clinical Sciences (L.C., M.T., W.T.D.) and Department of Veterinary Biosciences (C.K., M.O.), The Ohio State University, Columbus, Ohio
| |
Collapse
|
11
|
Kent LN, Bae S, Tsai SY, Tang X, Srivastava A, Koivisto C, Martin CK, Ridolfi E, Miller GC, Zorko SM, Plevris E, Hadjiyannis Y, Perez M, Nolan E, Kladney R, Westendorp B, de Bruin A, Fernandez S, Rosol TJ, Pohar KS, Pipas JM, Leone G. Dosage-dependent copy number gains in E2f1 and E2f3 drive hepatocellular carcinoma. J Clin Invest 2017; 127:830-842. [PMID: 28134624 DOI: 10.1172/jci87583] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 12/06/2016] [Indexed: 12/21/2022] Open
Abstract
Disruption of the retinoblastoma (RB) tumor suppressor pathway, either through genetic mutation of upstream regulatory components or mutation of RB1 itself, is believed to be a required event in cancer. However, genetic alterations in the RB-regulated E2F family of transcription factors are infrequent, casting doubt on a direct role for E2Fs in driving cancer. In this work, a mutation analysis of human cancer revealed subtle but impactful copy number gains in E2F1 and E2F3 in hepatocellular carcinoma (HCC). Using a series of loss- and gain-of-function alleles to dial E2F transcriptional output, we have shown that copy number gains in E2f1 or E2f3b resulted in dosage-dependent spontaneous HCC in mice without the involvement of additional organs. Conversely, germ-line loss of E2f1 or E2f3b, but not E2f3a, protected mice against HCC. Combinatorial mapping of chromatin occupancy and transcriptome profiling identified an E2F1- and E2F3B-driven transcriptional program that was associated with development and progression of HCC. These findings demonstrate a direct and cell-autonomous role for E2F activators in human cancer.
Collapse
|
12
|
Kent LN, Rakijas JB, Pandit SK, Westendorp B, Chen HZ, Huntington JT, Tang X, Bae S, Srivastava A, Senapati S, Koivisto C, Martin CK, Cuitino MC, Perez M, Clouse JM, Chokshi V, Shinde N, Kladney R, Sun D, Perez-Castro A, Matondo RB, Nantasanti S, Mokry M, Huang K, Machiraju R, Fernandez S, Rosol TJ, Coppola V, Pohar KS, Pipas JM, Schmidt CR, de Bruin A, Leone G. E2f8 mediates tumor suppression in postnatal liver development. J Clin Invest 2016; 126:2955-69. [PMID: 27454291 DOI: 10.1172/jci85506] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 05/26/2016] [Indexed: 01/14/2023] Open
Abstract
E2F-mediated transcriptional repression of cell cycle-dependent gene expression is critical for the control of cellular proliferation, survival, and development. E2F signaling also interacts with transcriptional programs that are downstream of genetic predictors for cancer development, including hepatocellular carcinoma (HCC). Here, we evaluated the function of the atypical repressor genes E2f7 and E2f8 in adult liver physiology. Using several loss-of-function alleles in mice, we determined that combined deletion of E2f7 and E2f8 in hepatocytes leads to HCC. Temporal-specific ablation strategies revealed that E2f8's tumor suppressor role is critical during the first 2 weeks of life, which correspond to a highly proliferative stage of postnatal liver development. Disruption of E2F8's DNA binding activity phenocopied the effects of an E2f8 null allele and led to HCC. Finally, a profile of chromatin occupancy and gene expression in young and tumor-bearing mice identified a set of shared targets for E2F7 and E2F8 whose increased expression during early postnatal liver development is associated with HCC progression in mice. Increased expression of E2F8-specific target genes was also observed in human liver biopsies from HCC patients compared to healthy patients. In summary, these studies suggest that E2F8-mediated transcriptional repression is a critical tumor suppressor mechanism during postnatal liver development.
Collapse
|
13
|
Caserta E, Egriboz O, Wang H, Martin C, Koivisto C, Pecót T, Kladney RD, Shen C, Shim KS, Pham T, Karikomi MK, Mauntel MJ, Majumder S, Cuitino MC, Tang X, Srivastava A, Yu L, Wallace J, Mo X, Park M, Fernandez SA, Pilarski R, La Perle KMD, Rosol TJ, Coppola V, Castrillon DH, Timmers C, Cohn DE, O'Malley DM, Backes F, Suarez AA, Goodfellow P, Chamberlin HM, Macrae ER, Shapiro CL, Ostrowski MC, Leone G. Noncatalytic PTEN missense mutation predisposes to organ-selective cancer development in vivo. Genes Dev 2015; 29:1707-20. [PMID: 26302789 PMCID: PMC4561480 DOI: 10.1101/gad.262568.115] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Caserta et al. generated and analyzed Pten knock-in mice harboring a C2 domain missense mutation at phenylalanine 341 (PtenFV), found in human cancer. This PTEN noncatalytic missense mutation exposes a core tumor suppressor function distinct from inhibition of canonical AKT signaling that predisposes to organ-selective cancer development in vivo. Inactivation of phosphatase and tensin homology deleted on chromosome 10 (PTEN) is linked to increased PI3K–AKT signaling, enhanced organismal growth, and cancer development. Here we generated and analyzed Pten knock-in mice harboring a C2 domain missense mutation at phenylalanine 341 (PtenFV), found in human cancer. Despite having reduced levels of PTEN protein, homozygous PtenFV/FV embryos have intact AKT signaling, develop normally, and are carried to term. Heterozygous PtenFV/+ mice develop carcinoma in the thymus, stomach, adrenal medulla, and mammary gland but not in other organs typically sensitive to Pten deficiency, including the thyroid, prostate, and uterus. Progression to carcinoma in sensitive organs ensues in the absence of overt AKT activation. Carcinoma in the uterus, a cancer-resistant organ, requires a second clonal event associated with the spontaneous activation of AKT and downstream signaling. In summary, this PTEN noncatalytic missense mutation exposes a core tumor suppressor function distinct from inhibition of canonical AKT signaling that predisposes to organ-selective cancer development in vivo.
Collapse
Affiliation(s)
- Enrico Caserta
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Onur Egriboz
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Hui Wang
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Chelsea Martin
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Christopher Koivisto
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Thierry Pecót
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Raleigh D Kladney
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Changxian Shen
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Kang-Sup Shim
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Thac Pham
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Matthew K Karikomi
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Melissa J Mauntel
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Sarmila Majumder
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Maria C Cuitino
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Xing Tang
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Arunima Srivastava
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Lianbo Yu
- Center for Biostatistics, The Ohio State University, Columbus, Ohio 43210, USA; Department of Biomedical Informatics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Julie Wallace
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Xiaokui Mo
- Center for Biostatistics, The Ohio State University, Columbus, Ohio 43210, USA; Department of Biomedical Informatics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Morag Park
- Department of Biochemistry, McGill University, Montreal, Quebec H3A 1A1, Canada; Rosalind and Morris Goodman Cancer Center, McGill University, Montreal, Quebec H3A 1A1, Canada; Department of Oncology, McGill University, Montreal, Quebec H3A 1A1, Canada
| | - Soledad A Fernandez
- Center for Biostatistics, The Ohio State University, Columbus, Ohio 43210, USA; Department of Biomedical Informatics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Robert Pilarski
- Department of Internal Medicine, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - Krista M D La Perle
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Thomas J Rosol
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Vincenzo Coppola
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Diego H Castrillon
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Cynthia Timmers
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - David E Cohn
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, The Ohio State University, Columbus, Ohio 43210, USA
| | - David M O'Malley
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Floor Backes
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Adrian A Suarez
- Department of Pathology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Paul Goodfellow
- Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA; Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Helen M Chamberlin
- Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA
| | - Erin R Macrae
- Division of Medical Oncology, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Charles L Shapiro
- Division of Medical Oncology, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Michael C Ostrowski
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Gustavo Leone
- Solid Tumor Biology Program, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Genetics, College of Arts and Sciences, The Ohio State University, Columbus, Ohio 43210, USA; Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| |
Collapse
|
14
|
Liu H, Tang X, Srivastava A, Pécot T, Daniel P, Hemmelgarn B, Reyes S, Fackler N, Bajwa A, Kladney R, Koivisto C, Chen Z, Wang Q, Huang K, Machiraju R, Sáenz-Robles MT, Cantalupo P, Pipas JM, Leone G. Redeployment of Myc and E2f1-3 drives Rb-deficient cell cycles. Nat Cell Biol 2015; 17:1036-48. [PMID: 26192440 PMCID: PMC4526313 DOI: 10.1038/ncb3210] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 06/22/2015] [Indexed: 02/07/2023]
Abstract
Robust mechanisms to control cell proliferation have evolved to maintain the integrity of organ architecture. Here, we investigated how two critical proliferative pathways, Myc and E2f, are integrated to control cell cycles in normal and Rb-deficient cells using a murine intestinal model. We show that Myc and E2f1-3 have little impact on normal G1-S transitions. Instead, they synergistically control an S-G2 transcriptional program required for normal cell divisions and maintaining crypt-villus integrity. Surprisingly, Rb deficiency results in the Myc-dependent accumulation of E2f3 protein and chromatin repositioning of both Myc and E2f3, leading to the 'super activation' of a G1-S transcriptional program, ectopic S phase entry and rampant cell proliferation. These findings reveal that Rb-deficient cells hijack and redeploy Myc and E2f3 from an S-G2 program essential for normal cell cycles to a G1-S program that re-engages ectopic cell cycles, exposing an unanticipated addiction of Rb-null cells on Myc.
Collapse
Affiliation(s)
- Huayang Liu
- 1] Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA [2] Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio 43210, USA [3] Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - Xing Tang
- 1] Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA [2] Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio 43210, USA [3] Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - Arunima Srivastava
- 1] Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA [2] Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio 43210, USA [3] Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - Thierry Pécot
- 1] Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA [2] Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio 43210, USA [3] Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - Piotr Daniel
- 1] Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA [2] Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio 43210, USA [3] Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - Benjamin Hemmelgarn
- 1] Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA [2] Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio 43210, USA [3] Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - Stephan Reyes
- 1] Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA [2] Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio 43210, USA [3] Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - Nicholas Fackler
- 1] Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA [2] Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio 43210, USA [3] Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - Amneet Bajwa
- 1] Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA [2] Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio 43210, USA [3] Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - Raleigh Kladney
- 1] Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA [2] Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio 43210, USA [3] Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - Christopher Koivisto
- 1] Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA [2] Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio 43210, USA [3] Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - Zhong Chen
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Qianben Wang
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Kun Huang
- Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio 43210, USA
| | - Raghu Machiraju
- Department of Computer Science and Engineering, The Ohio State University, Columbus, Ohio 43210, USA
| | | | - Paul Cantalupo
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - James M Pipas
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Gustavo Leone
- 1] Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA [2] Department of Molecular Genetics, College of Biological Sciences, The Ohio State University, Columbus, Ohio 43210, USA [3] Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| |
Collapse
|
15
|
Sáenz Robles MT, Chong JL, Koivisto C, Trimboli A, Liu H, Leone G, Pipas JM. Viral oncogene expression in the stem/progenitor cell compartment of the mouse intestine induces adenomatous polyps. Mol Cancer Res 2014; 12:1355-64. [PMID: 24994749 DOI: 10.1158/1541-7786.mcr-14-0166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
UNLABELLED Genetic and epigenetic events that alter gene expression and/or protein function or localization are thought to be the primary mechanism that drives tumorigenesis and governs the clinical behavior of cancers. Yet, a number of studies have shown that the effects of oncogene expression or tumor suppressor ablation are highly dependent on cell type. The molecular basis for this cell-type specificity and how it contributes to tumorigenesis are unknown. Here, expression of a truncated SV40 large T antigen in murine intestinal crypts promoted the formation of numerous adenomatous polyps in the colon and small intestine. In contrast, when the same T-antigen construct is expressed in villous enterocytes, the consequences are limited to hyperplasia and dysplasia. The T-antigen-induced polyps show high levels of the proto-oncogene c-Myc protein even though there is no transport of β-catenin to the nucleus. Targeting the expression of viral oncogenes to intestinal crypts or villi provides a murine model system for studying cell-type specific effects in tumorigenesis, and is particularly relevant to the study of APC/β-catenin-independent pathways contributing to the generation of intestinal polyps. IMPLICATIONS This mouse model system describes the formation of colon polyps in the absence of Wnt/β-catenin signaling.
Collapse
Affiliation(s)
| | - Jean Leon Chong
- Department of Human Genetics and Cancer Center, Ohio State University, Columbus, Ohio
| | - Christopher Koivisto
- Department of Human Genetics and Cancer Center, Ohio State University, Columbus, Ohio
| | - Anthony Trimboli
- Department of Human Genetics and Cancer Center, Ohio State University, Columbus, Ohio
| | - Huayang Liu
- Department of Human Genetics and Cancer Center, Ohio State University, Columbus, Ohio
| | - Gustavo Leone
- Department of Human Genetics and Cancer Center, Ohio State University, Columbus, Ohio
| | - James M Pipas
- Department of Biological Sciences, University of Pittsburgh. Pittsburgh, Pennsylvania.
| |
Collapse
|
16
|
Koivisto C, Flake GP, Kolenda-Roberts H, Masinde T, Kissling GE, Sills RC, Hoenerhoff MJ. Immunohistochemical investigation of F344/N rat islet cell tumors from national toxicology program studies. Toxicol Pathol 2012; 40:751-63. [PMID: 22477723 DOI: 10.1177/0192623312441407] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In this study, we have investigated the immunoexpression of peptide hormones and mediators associated with human islet cell tumors in a group of proliferative islet cell lesions in F344 rats including islet cell hyperplasias, adenomas, and carcinomas, as defined by conventional histopathologic criteria. All proliferative islets expressed synaptophysin, although decreased expression intensity was observed in hyperplasias and adenomas. Most of the proliferative lesions expressed insulin, which generally decreased as lesions progressed toward malignancy. The distribution of glucagon, somatostatin, and gastrin-expressing cells was altered in proliferative islet lesions but did not comprise a large proportion of cells. Islet cell tumors were associated with increased nuclear expression of cyclin-dependent kinase 4 as well as increased proliferating cell nuclear antigen and decreased β-catenin expression. c-Myelocytomatosis oncogene expression was variable. This is the first study to describe the immunophenotype of islet cell tumors in the F344 rat and to show that islet cell tumors in the F344 rat exhibit similarities in protein expression to the human counterpart.
Collapse
Affiliation(s)
- Christopher Koivisto
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | | | | | | | | | | | | |
Collapse
|
17
|
Frankenhuyzen KV, Geen GH, Koivisto C. Direct and indirect effects of low pH on the transformation of detrital energy by the shredding caddisfly, Clistoronia magnifica (Banks) (Limnephilidae). CAN J ZOOL 1985. [DOI: 10.1139/z85-341] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A shredding caddisfly, Clistoronia magnifica (Banks), was used to test the hypotheses that increased acidity would reduce the transformation of detrital energy into shredder biomass by (i) reducing survival, (ii) increasing maintenance costs at the expense of growth, and (iii) reducing food quality as a result of inhibition of microbial activity on the leaf litter. Low pH reduced larval survival immediately after hatching and during the moult from third to fourth instar. However, surviving larvae developed faster at pH 4.2–5.2 than at pH 5.8–6.4 and produced larger pupae and adults. Low pH did not alter metabolic costs or ingestion rates of fourth- and fifth-instar larvae. Accelerated growth resulted from indirect effects of low pH on the food resource, which suggested improved nutritional quality of leaf litter conditioned at low pH. However, enhanced growth of late instar larvae did not compensate for reduced survival of early instar larvae, possibly resulting in lower shredder production under acidic conditions.
Collapse
|