Cytogenetic studies of testicular germ cell tumors and tumor cell lines

4555 Background: Cisplatin-based chemotherapy cures over 80% of testicular germ cell tumors (TGCTs); nucleotide-excision repair (NER) modifies the sensitivity to cisplatin. In this work we explored the association between NER-proteins and their polymorphisms (SNPs) with cisplatin-sensitivity (CPS) and overall survival (OS) of patients with advanced non-seminomatous (ns)-TGCTs treated with bleomycin-etoposide-cisplatin (BEP). Methods: ERCC1, XPA-expression and gammaH2AX-presence, were tested in cisplatin-treated cancer cell lines. ERCC1 and XPA-expression were also analyzed in ns-TGCTs by qPCR. Immunohistochemistry was performed to detect ERCC1 protein in ns-TGCTs specimens. The SNPs were genotyped by PCR-RFLPs technique. Results: High basal ERCC1-expression was observed in non-CPS cancer cell lines; ERCC1-expression augmented further, as well as gammaH2AX, after cisplatin-treatment. Basal ERCC1 expression increases in the non-CPS patients in Mexican and Peruvian populations compared to CPS patients (p<0.001; p=0.002). XPAexpression levels weren’t different. These polymorphisms weren’t associated with CPS or OS. ERCC1-positive immunostaining was observed in 30/108 patients (27.8%). From 76 patients that were CPS, 59 (77.6%) were ERCC1-negative, compared with 17 (22.4%) that were ERCC1-positive (p=0.05). 5-year OS probability was smaller for those patients ERCC1-positive and non-CPS (15.38%) than tumor ERCC1-negative and CPS (89.3%) (p<0.001). Using the Cox Model, adjusted on the prognosis groups, the hazard ratio (HR) of death in patients with ERCC1-negative and non-CPS was >14.43 and in patients ERCC1-positive and non-CPS the HR was >11.86 (p<0.001). Conclusions: High-levels of ERCC1-expression and ERCC1-protein are associated with non-CPS, suggesting the use of ERCC1 as a potential indicator of response to cisplatin-based chemotherapy and the prognosis in patients with ns-TGCTs. Moreover, it’s important to identify patients potentially non-CPS in order to diminish the toxicity of cisplatin and improved quality of life avoiding adverse effects due to this agent. Work supported by CONACYT 83959 and PAPIIT IN213311-3.

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XIST-Promoter Demethylation as Tissue Biomarker for Testicular Germ Cell Tumors and Spermatogenesis Quality

Cancers ◽

10.3390/cancers11091385 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1385 ◽

Cited By ~ 9

Author(s):

Lobo ◽

Nunes ◽

Gillis ◽

Barros-Silva ◽

Miranda-Gonçalves ◽

...

Keyword(s):

Germ Cell ◽

Cell Lines ◽

X Chromosome ◽

Germ Cell Tumors ◽

X Chromosome Inactivation ◽

Chromosome Inactivation ◽

Lower Amount ◽

Testicular Germ Cell Tumors ◽

Testicular Germ Cell ◽

Xist Promoter

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.

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