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Soto-Heras S, Reinacher L, Wang B, Oh JE, Bunnell M, Park CJ, Hess RA, Ko CJ. Cryptorchidism and testicular cancer in the dog: unresolved questions and challenges in translating insights from human studies†. Biol Reprod 2024; 111:269-291. [PMID: 38738783 DOI: 10.1093/biolre/ioae075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 05/02/2024] [Accepted: 05/09/2024] [Indexed: 05/14/2024] Open
Abstract
Cryptorchidism, the failure of one or both testes to descend into the scrotum, and testicular cancer show a strong correlation in both dogs and humans. Yet, long-standing medical debates persist about whether the location of undescended testes directly causes testicular cancer in humans or if both conditions stem from a common origin. Although testicular cancer is a prevalent disease in dogs, even less is known about its cause and correlation with testicular descent in this species. This review investigates the relation between these two disorders in dogs, drawing insights from human studies, and examines key biomarkers identified thus far. In addition, it explores potential causal links, including the impact of temperature on maturing testicular cells and a potential shared genetic origin. Notably, this literature review reveals significant differences between men and dogs in reproductive development, histological and molecular features of testicular tumors, and the prevalence of specific tumor types, such as Sertoli cell tumors in cryptorchid dogs and germ cell tumors in humans. These disparities caution against using dogs as models for human testicular cancer research and underscore the limitations when drawing comparisons between species. The paper concludes by suggesting specific research initiatives to enhance our understanding of the complex interplay between cryptorchidism and testicular cancer in dogs.
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Affiliation(s)
- Sandra Soto-Heras
- Epivara, Inc., 2109 S. Oak Street, Suite 100A, Champaign, IL 61820, USA
| | - Lindsey Reinacher
- Epivara, Inc., 2109 S. Oak Street, Suite 100A, Champaign, IL 61820, USA
| | - Bensen Wang
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Ji Eun Oh
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Mary Bunnell
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Chan Jin Park
- Epivara, Inc., 2109 S. Oak Street, Suite 100A, Champaign, IL 61820, USA
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Rex A Hess
- Epivara, Inc., 2109 S. Oak Street, Suite 100A, Champaign, IL 61820, USA
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - CheMyong Jay Ko
- Epivara, Inc., 2109 S. Oak Street, Suite 100A, Champaign, IL 61820, USA
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
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Chai S, Huang X, Wu T, Xu S, Ren W, Yang G. Comparative genomics reveals molecular mechanisms underlying health and reproduction in cryptorchid mammals. BMC Genomics 2021; 22:763. [PMID: 34702182 PMCID: PMC8547080 DOI: 10.1186/s12864-021-08084-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 10/12/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mammals have wide variations in testicular position, with scrotal testes in some species and ascrotal testes in others. Although cryptorchidism is hazardous to human health, some mammalian taxa are natural cryptorchids. However, the evolution of testicular position and the molecular mechanisms underlying the maintenance of health, including reproductive health, in ascrotal mammals are not clear. RESULTS In the present study, comparative genomics and evolutionary analyses revealed that genes associated with the extracellular matrix and muscle, contributing to the development of the gubernaculum, were involved in the evolution of testicular position in mammals. Moreover, genes related to testicular position were significantly associated with spermatogenesis and sperm fertility. These genes showed rapid evolution and the signature of positive selection, with specific substitutions in ascrotal mammals. Genes associated with testicular position were significantly enriched in functions and pathways related to cancer, DNA repair, DNA replication, and autophagy. CONCLUSIONS Our results revealed that alterations in gubernaculum development contributed to the evolution of testicular position in mammals and provided the first support for two hypotheses for variation in testicular position in mammals, the "cooling hypothesis", which proposes that the scrotum provides a cool environment for acutely heat-sensitive sperm and the "training hypothesis", which proposes that the scrotum develops the sperm by exposing them to an exterior environment. Further, we identified cancer resistance and DNA repair as potential protective mechanisms in natural cryptorchids. These findings provide general insights into cryptorchidism and have implications for health and infertility both in humans and domestic mammals.
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Affiliation(s)
- Simin Chai
- School of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Xin Huang
- School of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Tianzhen Wu
- School of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Shixia Xu
- School of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Wenhua Ren
- School of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China.
| | - Guang Yang
- School of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China.
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Chai S, Tian R, Bi J, Xu S, Yang G, Ren W. Rapid evolution and molecular convergence in cryptorchidism-related genes associated with inherently undescended testes in mammals. BMC Ecol Evol 2021; 21:22. [PMID: 33568072 PMCID: PMC7877101 DOI: 10.1186/s12862-021-01753-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 01/28/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The mammalian testis is an important male exocrine gland and spermatozoa-producing organ that usually lies in extra-abdominal scrotums to provide a cooler environment for spermatogenesis and sperm storage. Testicles sometimes fail to descend, leading to cryptorchidism. However, certain groups of mammals possess inherently ascrotal testes (i.e. testes that do not descend completely or at all) that have the same physiological functions as completely descended scrotal testes. Although several anatomical and hormonal factors involved in testicular descent have been studied, there is still a paucity of comprehensive research on the genetic mechanisms underlying the evolution of testicular descent in mammals and how mammals with ascrotal testes maintain their reproductive health. RESULTS We performed integrative phenotypic and comparative genomic analyses of 380 cryptorchidism-related genes and found that the mammalian ascrotal testes trait is derived from an ancestral scrotal state. Rapidly evolving genes in ascrotal mammals were enriched in the Hedgehog pathway-which regulates Leydig cell differentiation and testosterone secretion-and muscle development. Moreover, some cryptorchidism-related genes in ascrotal mammals had undergone positive selection and contained specific mutations and indels. Genes harboring convergent/parallel amino acid substitutions between ascrotal mammals were enriched in GTPase functions. CONCLUSIONS Our results suggest that the scrotal testis is an ancestral state in mammals, and the ascrotal phenotype was derived multiple times in independent lineages. In addition, the adaptive evolution of genes involved in testicular descent and the development of the gubernaculum contributed to the evolution of ascrotal testes. Accurate DNA replication, the proper segregation of genetic material, and appropriate autophagy are the potential mechanisms for maintaining physiological normality during spermatogenesis in ascrotal mammals. Furthermore, the molecular convergence of GTPases is probably a mechanism in the ascrotal testes of different mammals. This study provides novel insights into the evolution of the testis and scrotum in mammals and contributes to a better understanding of the pathogenesis of cryptorchidism in humans.
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Affiliation(s)
- Simin Chai
- School of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Ran Tian
- School of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Juanjuan Bi
- School of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Shixia Xu
- School of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Guang Yang
- School of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China.
| | - Wenhua Ren
- School of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China.
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Urh K, Kolenc Ž, Hrovat M, Svet L, Dovč P, Kunej T. Molecular Mechanisms of Syndromic Cryptorchidism: Data Synthesis of 50 Studies and Visualization of Gene-Disease Network. Front Endocrinol (Lausanne) 2018; 9:425. [PMID: 30093884 PMCID: PMC6070605 DOI: 10.3389/fendo.2018.00425] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/09/2018] [Indexed: 12/17/2022] Open
Abstract
Background: Cryptorchidism is one of the most frequent congenital birth defects in male children and is present in 2-4% of full-term male births. It has several possible health effects including reduced fertility, increased risk for testicular neoplasia, testicular torsion, and psychological consequences. Cryptorchidism is often diagnosed as comorbid; copresent with other diseases. It is also present in clinical picture of several syndromes. However, this field has not been systematically studied. The aim of the present study was to catalog published cases of syndromes which include cryptorchidism in the clinical picture and associated genomic information. Methods: The literature was extracted from Public/Publisher MEDLINE and Web of Science databases, using the keywords including: syndrome, cryptorchidism, undescended testes, loci, and gene. The obtained data was organized in a table according to the previously proposed standardized data format. The results of the study were visually represented using Gephi and karyotype view. Results: Fifty publications had sufficient data for analysis. Literature analysis resulted in 60 genomic loci, associated with 44 syndromes that have cryptorchidism in clinical picture. Genomic loci included 38 protein-coding genes and 22 structural variations containing microdeletions and microduplications. Loci, associated with syndromic cryptorchidism are located on 16 chromosomes. Visualization of retrieved data is presented in a gene-disease network. Conclusions: The study is ongoing and further studies will be needed to develop a complete catalog with the data from upcoming publications. Additional studies will also be needed for revealing of molecular mechanisms associated with syndromic cryptorchidism and revealing complete diseasome network.
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Affiliation(s)
| | | | | | | | | | - Tanja Kunej
- Department of Animal Science, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
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