Chromosomes and expression in @entity1 testicular germ-cell XXXX : insight into their cell of origin and pathogenesis.

@entity1 @entity2085 @entity4729 @entity2735 @entity2440 @entity5 @entity900 @entity189 @entity4731 @entity876 @entity2969 @entity4797 @entity8882 @entity44
@entity1 germ-cell @entity5 (GCTs) are a heterogeneous group of @entity5 . Based on epidemiology, anatomical site of presentation, histology, chromosomal constitution, and pattern of genomic imprinting, GCTs are classified into five entities. Within the testis, three types of GCTs can be diagnosed: type I ( @entity44 and yolk-sac @entity5 of neonates and @entity1 ); type II (seminomas and nonseminomas); type III ( @entity2969 ). Here the focus is on the type II GCTs, the most frequent type in the adult testis (so-called TGCTs). They can also be diagnosed in dysgenetic gonads (an incomplete or defective formation of the gonad, caused by a disturbed process of migration of the germ cells and/or their correct organization in their fetal gonadal ridge), the anterior mediastinum, and pineal/suprasellar region. In the testis, they originate from the malignant counterpart of primordial germ cells/gonocytes, referred to as @entity2735 ( @entity2735 )/intratubular germ-cell neoplasia unclassified (ITGCNU). @entity2735 /ITGCNU and seminomatous cells are characterized by expression of @entity4729 and @entity2440 , while in addition @entity189 expresses @entity4731 , all identified as transcription factors related to pluripotency in @entity2085 ( @entity2085 ) cells. With the exception of @entity44 , most histological elements of TGCTs are sensitive for ( @entity900 -based) chemotherapy; @entity2735 /ITGCNU and @entity4797 cells are also sensitive to DNA damage induced by irradiation. Similar observations have been made for @entity2085 cells and their derivates. Moreover, the genetic constitution of TGCTs (low incidence of mutations and frequent @entity8882 ) can also be linked to characteristics of @entity2085 cells, likely related to their specific inability to repair DNA damage and their high sensitivity to apoptotic cell death. The unusual presence of wild-type @entity876 in TGCTs is explained by specific expression of a cluster of micro-RNAs (miRNAs), that is, hsa-miR 371-373, also expressed in @entity2085 cells, which prevents @entity876 -driven cellular senescence upon oncogenic stress. Many characteristics of @entity1 TGCTs reflect the nonmalignant counterparts from which they originate. Demonstration of these characteristics, in combination with the knowledge of the abnormal niche of these cells, normally occupied by spermatogonia, allows an informative method for (early) diagnosis. The conclusion is that TGCTs are @entity5 found in adults.
