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Svingen T, Jørgensen A, Rajpert-De Meyts E. Validation of endogenous normalizing genes for expression analyses in adult human testis and germ cell neoplasms. Mol Hum Reprod 2014; 20:709-18. [PMID: 24743772 DOI: 10.1093/molehr/gau030] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The measurement of gene expression levels in cells and tissues typically depends on a suitable point of reference for inferring biological relevance. For quantitative (or real-time) RT-PCR assays, the method of choice is often to normalize gene expression data to an endogenous gene that is stably expressed across the samples analysed: a so-called normalizing or housekeeping gene. Although this is a valid strategy, the identification of stable normalizing genes has proved challenging and a gene showing stable expression across all cells or tissues is unlikely to exist. Therefore, it is necessary to define suitable normalizing genes for specific cells and tissues. Here, we report on the performance of a panel of nine commonly employed normalizing genes in adult human testis and testicular pathologies. Our analyses revealed significant variability in transcript abundance for commonly used normalizers, highlighting the importance of selecting appropriate normalizing genes as comparative measurements can yield variable results when different normalizing genes are employed. Based on our results, we recommend using RPS20, RPS29 or SRSF4 when analysing relative gene expression levels in human testis and associated testicular pathologies. OCT4 and SALL4 can be used with caution as second-tier normalizers when determining changes in gene expression in germ cells and germ cell tumour components, but the relative transcript abundance appears variable between different germ cell tumour types. We further recommend that such studies should be accompanied by additional assessment of histology and cellularity of each sample.
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Affiliation(s)
- T Svingen
- Department of Growth and Reproduction, Copenhagen University Hospital (Rigshospitalet), Copenhagen DK-2100, Denmark
| | - A Jørgensen
- Department of Growth and Reproduction, Copenhagen University Hospital (Rigshospitalet), Copenhagen DK-2100, Denmark
| | - E Rajpert-De Meyts
- Department of Growth and Reproduction, Copenhagen University Hospital (Rigshospitalet), Copenhagen DK-2100, Denmark
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Rajpert-De Meyts E. Developmental model for the pathogenesis of testicular carcinoma in situ: genetic and environmental aspects. Hum Reprod Update 2006; 12:303-23. [PMID: 16540528 DOI: 10.1093/humupd/dmk006] [Citation(s) in RCA: 304] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Carcinoma in situ testis (CIS), also known as intratubular germ cell neoplasia (ITGCN), is a pre-invasive precursor of testicular germ cell tumours, the commonest cancer type of male adolescents and young adults. In this review, evidence supporting the hypothesis of developmental origin of testicular germ cell cancer is summarized, and the current concepts regarding aetiology and pathogenesis of this disease are critically discussed. Comparative studies of cell surface proteins (e.g. PLAP and KIT), some of the germ cell-specific markers (e.g. MAGEA4, VASA, TSPY and NY-ESO-1), supported by studies of regulatory elements of the cell cycle (e.g. p53, CHK2 and p19-INK4d) demonstrated a close similarity of CIS to primordial germ cells and gonocytes, consistent with the pre-meiotic origin of CIS. Recent gene expression profiling studies showed that CIS cells closely resemble embryonic stem cells (ESCs). The abundance of factors associated with pluripotency (NANOG and OCT-3/4) and undifferentiated state (AP-2gamma) may explain the remarkable pluripotency of germ cell neoplasms, which are capable of differentiating to various somatic tissue components of teratomas. Impaired gonadal development resulting in the arrest of gonocyte differentiation and retention of its embryonic features, associated with an increasing genomic instability, is the most probable model for the pathogenesis of CIS. Genomic amplification of certain chromosomal regions, e.g. 12p, may facilitate survival of CIS and further invasive progression. Genetic studies, have so far not identified gene polymorphisms predisposing to the most common non-familial testicular cancer, but this research has only recently begun. Association of CIS with other disorders, such as congenital genital malformations and some forms of impaired spermatogenesis, all rising in incidence in a synchronous manner, led to the hypothesis that CIS might be a manifestation of testicular dysgenesis syndrome (TDS). The aetiology of TDS including testicular cancer remains to be elucidated, but epidemiological trends suggest a primary role for environmental factors, probably combined with genetic susceptibility.
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Affiliation(s)
- Ewa Rajpert-De Meyts
- University Department of Growth and Reproduction, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark.
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von Eyben FE. Chromosomes, genes, and development of testicular germ cell tumors. ACTA ACUST UNITED AC 2004; 151:93-138. [PMID: 15172750 DOI: 10.1016/j.cancergencyto.2003.09.008] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2003] [Revised: 09/01/2003] [Accepted: 09/09/2003] [Indexed: 12/25/2022]
Abstract
A literature review found 265 articles on testicular germ cell tumors (TGCTs) detailing the copy number of chromosomal regions and expression of 245 genes. An initial precursor stage, intratubular germ cell neoplasia (IGCN), is characterized by triploidization and an upregulation of KIT, ALPP, CCDN2, and ZNF354A, and a downregulation of CDKN2D. TGCT regularly have a series of chromosomal aberrations: a decrease in copy number at 4q21 approximately qter and 5q14 approximately qter; an increase at 7p21 approximately pter, 7q21 approximately q33, and 8q12 approximately q23 (especially high increase in seminoma); a decrease at 11p11 approximately p15 and 11q14 approximately q24; an increase at 12p11 approximately pter; a decrease at 13q14 approximately q31; an increase of 17q11 approximately q21 (only for nonseminoma); a decrease of 18q12 approximately qter; and an increase at 21q21 approximately qter, 22q11 approximately qter (only for seminoma), and Xq. Macroscopically overt TGCT is associated with a characteristic series of abnormalities in the retinoblastoma pathway including upregulation of cyclin D2 and p27 and downregulation of RB1 and the cyclin-dependent kinase inhibitors p16, p18, p19, and p21. TGCT thus has a synergistic pattern in gene expressions of the retinoblastoma pathway that is rare in other malignancies.
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Affiliation(s)
- Finn Edler von Eyben
- Medical Knowledge Center, Odense University Hospital, DK-5000 Odense M, Denmark.
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Gundy S, Babosa M, Baki M, Bodrogi I. Increased predisposition to cancer in brothers and offspring of testicular tumor patients. Pathol Oncol Res 2004; 10:197-203. [PMID: 15619639 DOI: 10.1007/bf03033760] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2004] [Accepted: 11/20/2004] [Indexed: 12/17/2022]
Abstract
Cancer susceptibility was examined in first-degree relatives of 293 testicular tumor patients (TTPs) and 586 age-matched healthy males. Significantly increased risk was found in the families of TTPs (OR: 1.4; CI: 1.08-1.79), however, except for testicular cancer of 7 brothers (OR: 11.7; CI: 1.42-256.5), and 6 various childhood tumors (bilateral Wilms' tumor, neuroblastoma, medulloblastoma, ALL, histiocytosis-X, testicular tumor) of 200 offspring (OR: 12.9; CI: 1.54-286.2), no association with other malignancies was observed. No differences were seen between the fertility of patients and controls when occupational or socio-economic status of the families was taken into account. However, the majority of the controls (85%) fathered the first child between 20-30 years of age, while only 61% of TTPs had the first child in the same age group. TTPs fathered more girls than boys (P=0.009), and the lower male - higher female ratio of index children was also identical, irrespective of the conception taking place before or after the father's treatment. Occupations did not, but smoking might have influenced cancer susceptibility of the patients. Aggregation of fraternal testicular tumors, and both dramatically increased cancer risk and altered sex ratio of the offspring indicate a remarkable role of hereditary factors in tumorigenesis and later consequences of a certain portion of testicular malignancies, which must be refined by molecular studies.
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Affiliation(s)
- Sarolta Gundy
- Department of Onco-Cytogenetics, National Institute of Oncology, Budapest, Hungary.
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Toppari J, Haavisto AM, Alanen M. Changes in male reproductive health and effects of endocrine disruptors in Scandinavian countries. CAD SAUDE PUBLICA 2002; 18:413-20. [PMID: 11923882 DOI: 10.1590/s0102-311x2002000200005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Male reproductive health has deteriorated in many ways during the last decades. The incidence of testicular cancer has rapidly increased in Europe and European-derived populations. Sperm concentrations have declined and sperm motility and morphology have worsened in many areas. Both adverse trends have been shown to be associated with year of birth. Older birth cohorts have better reproductive health than the younger generations. Incidences of cryptorchidism and hypospadias have also increased according to several studies. The reasons for secular trends are unknown, but the rapid pace of the change points to environmental causes. Endocrine disrupting chemicals have been hypothesized to influence male reproductive health.
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Affiliation(s)
- Jorma Toppari
- Department of Pediatrics, University of Turku, Turku, Finland.
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Muroya K, Ishii T, Nakahori Y, Asakura Y, Tachibana K, Masuno M, Imaizumi K, Tanaka Y, Kawada Y, Yukizane S, Ogata T. Gonadoblastoma, mixed germ cell tumor, and Y chromosomal genotype: molecular analysis in four patients. Genes Chromosomes Cancer 1999; 25:40-5. [PMID: 10221338 DOI: 10.1002/(sici)1098-2264(199905)25:1<40::aid-gcc6>3.0.co;2-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
This study reports on Y chromosomal genotypes of three patients with gonadoblastoma and one patient with gonadoblastoma and mixed germ cell tumor. Molecular analysis for 35 Y chromosomal loci was performed for DNA samples taken from peripheral leukocytes and lymphoblastoid cell lines, showing that the four patients shared the region between DYS267 at interval 4A and DYF50S1 at interval 6D, with the exception of the region around DYS202 at interval 5K. In the patient with gonadoblastoma and mixed germ cell tumor, Y chromosomal material was preserved in the gonadoblastoma but was lost from the mixed germ cell tumor. The results, in conjunction with previous reports, suggest that GBY (gonadoblastoma locus on the Y chromosome) may be located to a roughly 5-Mb pericentromeric region between DYS267 at interval 4A and DYS270 at interval 5A. The presence of Y chromosomal material in gonadoblastoma is consistent with GBY being involved in the development of gonadoblastoma, and the absence of Y chromosomal material in mixed germ cell tumor would be explained as a consequence of Y chromosomal loss from rapidly proliferating gonadal cancer cells.
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Affiliation(s)
- K Muroya
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
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Abstract
Potential tumor markers for testis cancer have become numerous with the new molecular techniques available. New protein markers have been evaluated, and histologic factors have shown correlations with stage of disease. Cytogenetic analysis studies have also shown associations with stage progression. Chromosomal markers, oncogenes, and tumor suppressor genes are possible candidates for tumor markers. These new potential tumor markers may become as commonplace as the established markers and may enhance diagnosis, staging, and treatment of testis cancer.
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Affiliation(s)
- R C Dean
- Department of Surgery, Walter Reed Army Medical Center, Washington, DC, USA
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Strohmeyer TG, Slamon DJ. Proto-oncogenes and tumor suppressor genes in human urological malignancies. J Urol 1994; 151:1479-97. [PMID: 8189554 DOI: 10.1016/s0022-5347(17)35284-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- T G Strohmeyer
- Department of Medicine, Jonsson Comprehensive Cancer Center, University of California, Los Angeles
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Kovacs G, Tory K, Kovacs A. Development of papillary renal cell tumours is associated with loss of Y-chromosome-specific DNA sequences. J Pathol 1994; 173:39-44. [PMID: 7931836 DOI: 10.1002/path.1711730107] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Twenty-two papillary renal cell tumours were analysed by Southern hybridization using eight DNA probes from homologous regions of the X and Y chromosomes and two Y-chromosome-specific DNA probes. Sixteen of the 19 papillary renal cell tumours of male patients showed the loss of Y-chromosome-specific sequences. No loss of heterozygosity was detected in three tumours that developed in females. The frequency of loss of the Y chromosome was established in 50 non-papillary renal cell carcinomas as well. Only seven of the 31 non-papillary renal cell carcinomas obtained from male patients had lost the Y-chromosome-specific sequences, whereas no allelic loss was found in 19 non-papillary tumours obtained from female patients. Papillary renal cell tumours show a strong male preponderance (6:1) and loss of Y chromosome in 84 per cent of the cases, whereas non-papillary renal cell carcinomas show only a slight male preponderance (1.5:1) and the Y chromosome is lost in only 22 per cent of the cases. These data suggest that a tumour suppressor gene is localized at one of the homologous regions of the X and Y chromosomes, the homozygous inactivation of which is associated with the development of papillary renal cell tumours.
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Affiliation(s)
- G Kovacs
- Institute of Neuropathology, University Hospital, Zürich, Switzerland
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Affiliation(s)
- G Kovacs
- National Cancer Center Research Institute, Tokyo, Japan
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Peltomäki P, Lothe RA, Børresen AL, Fosså SD, Brøgger A, de la Chapelle A. Chromosome 12 in human testicular cancer: dosage changes and their parental origin. CANCER GENETICS AND CYTOGENETICS 1992; 64:21-6. [PMID: 1458445 DOI: 10.1016/0165-4608(92)90316-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cytogenetically, a marker chromosome interpreted as i(12p) is present in most testicular tumors of germ cell origin. In this study, 22 patients with testicular germ-cell tumors were investigated by Southern blot hybridization to characterize changes in chromosome 12. In comparison with normal DNA, tumor DNA of 18 patients showed increased dosages of 12p accompanied by a comparable or smaller increase or no change in the dosage of centromeric sequences of chromosome 12. A likely interpretation was that most testicular tumors had one or several isochromosomes for 12p that were formed by somatic division of the centromere and that the points of breakage and reunion in the centromeric region were different in different tumors. Allelic 12p fragments showing increased intensity were paternal in four and maternal in three of seven informative cases. Thus, there was no evidence of sex-limited parental imprinting. Furthermore, the observed patterns of allelic fragments suggested that the marker was an i(12p) formed by sister chromatids of one homolog number 12 rather than the result of interchange of genetic material between different homologues.
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Affiliation(s)
- P Peltomäki
- Department of Medical Genetics, University of Helsinki, Finland
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12
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Atkin NB, Baker MC. X-chromatin, sex chromosomes, and ploidy in 37 germ cell tumors of the testis. CANCER GENETICS AND CYTOGENETICS 1992; 59:54-6. [PMID: 1555191 DOI: 10.1016/0165-4608(92)90158-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
X-chromatin was present in interphase cells from nine of 14 teratomas and all of three combined tumors, but only one of 20 seminomas (which tended to have higher chromosome numbers). Eight of the 37 tumors were karyotyped; seven, only one of which (a teratoma) was X-chromatin-positive, had two X chromosomes while one, the X-chromatin-positive seminoma, had three. A possible relationship between the presence of inactive, X-chromatin-forming, X chromosomes and the number of autosomes is suggested by the data on the eight karyotyped tumors; the ratio of the number of Xs to the number of autosomes was higher for the two X-chromatin-positive tumors than for the remainder. All eight had at least one Y chromosome, and eight further tumors had one to three Y-bodies in their interphase cells. It is uncertain whether retention of the Y is a characteristic of male germ cell tumors, as tumors lacking a Y have been described by other workers. Two characteristics of these tumors, however, are high ploidy (at least 55 chromosomes), perhaps signifying an origin from a triploid or tetraploid cell, and chromosome 12 aberrations, usually resulting in an i(12p).
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Affiliation(s)
- N B Atkin
- Department of Cancer Research, Mount Vernon Hospital, Northwood, Middlesex, U.K
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