Selected Grantee Publications
Metabolic Transitions Define Spermatogonial Stem Cell Maturation
Voigt et al., Human Reproduction. 2022.
https://www.doi.org/10.1093/humrep/deac157
The spermatogonial stem cell (SSC) is the basis of male fertility. One potential option to preserve fertility in patients treated with anti-cancer therapy is isolation and laboratory culture of the juvenile SSC pool with subsequent transplantation to restore spermatogenesis. However, efficient culture of undifferentiated spermatogonia, including SSCs, in mammals other than rodents remains challenging. Investigators reported that the metabolic phenotype of prepubertal human spermatogonia is distinct from that of adult spermatogonia and that SSC development is characterized by specific metabolic transitions from oxidative phosphorylation to anaerobic metabolism. Supported by ORIP (R01OD016575) and NICHD.
Rbbp4 Loss Disrupts Neural Progenitor Cell Cycle Regulation Independent of Rb and Leads to Tp53 Acetylation and Apoptosis
Schultz-Rogers et al., Developmental Dynamics. 2022.
https://www.doi.org/10.1002/dvdy.467
Retinoblastoma binding protein 4 (Rbbp4) is a component of transcription regulatory complexes that control cell cycle gene expression by cooperating with the Rb tumor suppressor to block cell cycle entry. The authors used genetic analysis to examine the interactions of Rbbp4, Rb, and Tp53 in zebrafish neural progenitor cell cycle regulation and survival. Rbbp4 is upregulated across the spectrum of human embryonal and glial brain cancers, and it is essential for zebrafish neurogenesis. Rbbp4 loss leads to apoptosis and γ-H2AX in the developing brain that is suppressed by tp53 knockdown or maternal zygotic deletion. Mutant retinal neural precursors accumulate in M phase and fail to initiate G0 gene expression. Rbbp4; Rb1 double mutants show an additive effect on the number of M phase cells. The study demonstrates that Rbbp4 is necessary for neural progenitor cell cycle progression and initiation of G0, independent of Rb, and suggests that Rbbp4 is required for cell cycle exit and contributes to neural progenitor survival. Supported by ORIP (R24OD020166) and NIGMS.
Stromal P53 Regulates Breast Cancer Development, the Immune Landscape, and Survival in an Oncogene-Specific Manner
Wu et al., Molecular Cancer Research. 2022.
https://www.doi.org/10.1158/1541-7786.MCR-21-0960
Loss of stromal p53 function drives tumor progression in breast cancer, but the exact mechanisms have been relatively unexplored. Using mouse models, researchers demonstrated that loss of cancer-associated fibroblast (CAF) p53 enhances carcinoma formation driven by oncogenic KRAS G12D, but not ERBB2, in mammary epithelia. These results corresponded with increased tumor cell proliferation and DNA damage, as well as decreased apoptosis, in the KRAS G12D model. Furthermore, a gene cluster associated with CAF p53 deficiency was found to associate negatively with survival in microarray and heat map analyses. These data indicate that stromal p53 loss promotes mammary tumorigenesis in an oncogene-specific manner, influences the tumor immune landscape, and ultimately affects patient survival. Supported by ORIP (K01OD026527) and NCI.
Antibody-Peptide Epitope Conjugates for Personalized Cancer Therapy
Zhang et al., Cancer Research. 2022.
https://pubmed.ncbi.nlm.nih.gov/34965933/
Antibody-peptide epitope conjugates (APEC) are a new class of modified antibody-drug conjugates that redirect T cell viral immunity against tumor cells. Investigators developed an experimental pipeline to create patient-specific APECs and identified new preclinical therapies for ovarian carcinoma. Based on functional assessment of viral peptide antigen responses to common viruses like cytomegalovirus in ovarian cancer patients, a library of 192 APECs with distinct protease cleavage sequences was created using the anti-epithelial cell adhesion molecule (EpCAM) antibody. The streamlined and systemic approach includes assessing APEC function in vivo using a new zebrafish xenograft platform that facilitates high-resolution single-cell imaging to assess therapy responses and then validating top candidates using traditional mouse xenograft studies and primary patient samples. This study develops a high-throughput preclinical platform to identify patient-specific antibody-peptide epitope conjugates that target cancer cells and demonstrates the potential of this immunotherapy approach for treating ovarian carcinoma. Supported by ORIP (R24OD016761).
Intra-Strain Genetic Variation of Platyfish (Xiphophorus maculatus) Strains Determines Tumorigenic Trajectory
Lu et al., Frontiers in Genetics . 2020.
https://www.frontiersin.org/articles/10.3389/fgene.2020.562594/full
Xiphophorus interspecies hybrids represent a valuable model system to study heritable tumorigenesis. Although the ancestors of the two X. maculatus parental lines, Jp163 A and Jp163 B, were siblings produced by the same mother, backcross interspecies hybrid progeny between X. hellerii and X. maculatus Jp163 A develop spontaneous melanoma initiating at the dorsal fin due to a regulator encoded by the X. maculatus genome; the backcross hybrid progeny with X. hellerii or X. couchianus and Jp163 B exhibit melanoma on their flanks. Comparative genomic analyses revealed genetic differences are associated with pathways highlighting fundamental cellular functions. Disruption of these baselines may give rise to spontaneous or inducible tumorigenesis. Supported by ORIP (R24OD011120), NCI, and NIGMS.
Induction and Characterization of Pancreatic Cancer in a Transgenic Pig Model
Boas et al., PLOS One. 2020.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0239391
Preclinical testing of new therapies for pancreatic cancer has been challenging due to lack of a suitable large animal model. Pigs, however, have similar physiology and immune response to humans. Boas et al report the development of a porcine model for pancreatic cancer. H&E and immunohistochemical stains revealed undifferentiated carcinomas, like those of human pancreatobiliary systems. In several pigs, angiographies revealed that the artery supplying the pancreatic tumor could be catheterized using a 2.4 F microcatheter. In summary, pancreatic cancer can be induced in a transgenic pig, and intra-arterial procedures using catheters designed for human interventions were feasible in this model. Supported by ORIP (U42OD011140) and NCI.