TY - JOUR
T1 - XIST-promoter demethylation as tissue biomarker for testicular germ cell tumors and spermatogenesis quality
AU - Lobo, João
AU - Nunes, Sandra P.
AU - Gillis, Ad J.M.
AU - Barros-Silva, Daniela
AU - Miranda-Gonçalves, Vera
AU - van den Berg, Annette
AU - Cantante, Mariana
AU - Guimarães, Rita
AU - Henrique, Rui
AU - Jerónimo, Carmen
AU - Looijenga, Leendert H.J.
N1 - Publisher Copyright:
© 2019 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2019/9
Y1 - 2019/9
N2 - BACKGROUND: The event of X chromosome inactivation induced by XIST, which is physiologically observed in females, is retained in testicular germ cell tumors (TGCTs), as a result of a supernumerary X chromosome constitution. X chromosome inactivation also occurs in male germline, specifically during spermatogenesis. We aimed to analyze the promoter methylation status of XIST in a series of TGCT tissues, representative cell lines, and testicular parenchyma.METHODS: Two independent cohorts were included, comprising a total of 413 TGCT samples, four (T)GCT cell lines, and 86 testicular parenchyma samples. The relative amount of methylated and demethylated XIST promoter fragments was assessed by quantitative methylation-specific PCR (qMSP) and more sensitive high-resolution melting (HRM) methylation analyses.RESULTS: Seminomas showed a lower amount of methylated XIST fragments as compared to non-seminomas or normal testis (p < 0.0001), allowing for a good discrimination among these groups (area under the curve 0.83 and 0.81, respectively). Seminomas showed a significantly higher content of demethylated XIST as compared to non-seminomas. The percentage of demethylated XIST fragment in cell lines reflected their chromosomal constitution (number of extra X chromosomes). A novel and strong positive correlation between the Johnsen's score and XIST demethylation was identified (r = 0.75, p < 0.0001).CONCLUSIONS: The X chromosome inactivation event and demethylated XIST promoter are promising biomarkers for TGCTs and for assessing spermatogenesis quality.
AB - BACKGROUND: The event of X chromosome inactivation induced by XIST, which is physiologically observed in females, is retained in testicular germ cell tumors (TGCTs), as a result of a supernumerary X chromosome constitution. X chromosome inactivation also occurs in male germline, specifically during spermatogenesis. We aimed to analyze the promoter methylation status of XIST in a series of TGCT tissues, representative cell lines, and testicular parenchyma.METHODS: Two independent cohorts were included, comprising a total of 413 TGCT samples, four (T)GCT cell lines, and 86 testicular parenchyma samples. The relative amount of methylated and demethylated XIST promoter fragments was assessed by quantitative methylation-specific PCR (qMSP) and more sensitive high-resolution melting (HRM) methylation analyses.RESULTS: Seminomas showed a lower amount of methylated XIST fragments as compared to non-seminomas or normal testis (p < 0.0001), allowing for a good discrimination among these groups (area under the curve 0.83 and 0.81, respectively). Seminomas showed a significantly higher content of demethylated XIST as compared to non-seminomas. The percentage of demethylated XIST fragment in cell lines reflected their chromosomal constitution (number of extra X chromosomes). A novel and strong positive correlation between the Johnsen's score and XIST demethylation was identified (r = 0.75, p < 0.0001).CONCLUSIONS: The X chromosome inactivation event and demethylated XIST promoter are promising biomarkers for TGCTs and for assessing spermatogenesis quality.
KW - Methylation
KW - Molecular biomarkers
KW - Spermatogenesis
KW - Testicular germ cell tumors
KW - XIST promoter
UR - http://www.scopus.com/inward/record.url?scp=85073413264&partnerID=8YFLogxK
U2 - 10.3390/cancers11091385
DO - 10.3390/cancers11091385
M3 - Article
C2 - 31533343
VL - 11
JO - Cancers
JF - Cancers
IS - 9
M1 - 1385
ER -