In Search of TGCT Biomarkers: A Comprehensive In Silico and Histopathological Analysis

Abstract

Testicular germ cell tumors (TGCTs) are ever more affecting the young male population. Germ cell neoplasia in situ (GCNIS) is the origin of TGCTs, namely, seminomas (SE) and a heterogeneous group of nonseminomas (NS) comprising embryonal carcinoma, teratoma, yolk sac tumor, and choriocarcinoma. Response to the treatment and prognosis, especially of NS, depend on precise diagnosis with a necessity for discovery of new biomarkers. We aimed to perform comprehensive in silico analysis at the DNA, RNA, and protein levels of six prospective (HOXA9, MGMT, CFC1, PRSS21, RASSF1A, and MAGEC2) and six known TGCT biomarkers (OCT4, SOX17, SOX2, SALL4, NANOG, and KIT) and assess its congruence with histopathological analysis in all forms of TGCTs. Cancer Hallmarks Analytics Tool, the Search Tool for the Retrieval of Interacting Genes/Proteins database, and UALCAN, an interactive web resource for analyzing cancer OMICS data, were used. In 108 TGCT and 48 tumor-free testicular samples, the immunoreactivity score (IRS) was calculated. SE showed higher frequency in DNA alteration, while DNA methylation was significantly higher for all prospective biomarkers in NS. In GCNIS, we assessed the clinical positivity of RASSF1 and PRSS21 in 52% and 62% of samples, respectively, in contrast to low or nil positivity in healthy seminiferous tubules, TGTCs as a group, SE, NS, or all NS components. Although present in approximately 80% of healthy seminiferous tubules (HT) and GCNIS, HOXA9 was diagnostically positive in 64% of TGCTs, while it was positive in 82% of NS versus 29% of SE. Results at the DNA, mRNA, and protein levels on putative and already known biomarkers were included in the suggested panels that may prove to be important for better diagnostics of various forms of TGCTs.

Testicular Germ Cell Tumors: Serological and Immunohistochemical Diagnosis

“…Genetic and molecular biologic profiling of GCT has been performed in numerous laboratories providing genetic underpinning to the clinical and serologic tests. Many of these genetic studies, including those that are still in the experimental stage, have been reviewed in detail in several lengthy articles (106)(107)(108)(109)(110)(111)(112)(113), clearly showing that molecular biology will play a pivotal role in future research and many international efforts to refine the diagnosis of testicular GCT. Collaborative initiatives such as Gene Expression Omnibus (GEO), an international public repository that archives and freely distributes microarray and nextgeneration sequencing (NGS) data, could facilitate the search for novel GCT markers (114).…”

CNV Hotspots in Testicular Seminoma Tissue and Seminal Plasma

“…Therefore, we investigated CNVs of specific genes, located on the chromosomal regions with detected gains in SE. In addition, aberrant expression of selected genes in SE was reported [ 5 ]. The investigation was conducted not only on tissue samples but on seminal plasma samples as well.…”

“…All TGCT arises from the same precursor lesion, the germ cell neoplasia in situ (GCNIS) [ 4 ], but based on their degree of differentiation and histological characteristics, TGCT are divided into seminomas (SE) and nonseminomas. SE represents approximately 55% of all TGCT cases [ 5 ].…”

“…KITLG takes part in the KIT-KITLG signal pathway, which is a central pathway in TGCT tumorigenesis [ 16 ]. MAGEC2 is a cancer-testis gene, for which disturbed protein expression is associated with SE [ 5 ]. RASSF1A is a tumour-suppressor gene whose methylation is altered in various cancers [ 17 ].…”

Glycan signatures for the identification of cisplatin‐resistant testicular cancer cell lines: Specific glycoprofiling of human chorionic gonadotropin (hCG)

“…Testicular cancer (TC) is the most frequent type of cancer among young men aged between 15 and 34 years and represents 1.5% of all cancer types in men and 5% of urological tumours overall 1 . The current annual TC incidence is 10 new cases per 100,000 men in Western countries with an annual increase of up to 6% in Caucasian populations 1 and with a projected annual incidence of 85,635 new cases worldwide by 2040 2 . This is due to environmental risk factors, together with a genetic contribution 3 .…”