Shuin T, Misaki H, Kubota Y, Yao M, Hosaka M
Department of Urology, Yokohama City University School of Medicine, Japan.
Cancer. 1994 Mar 15;73(6):1721-7. doi: 10.1002/1097-0142(19940315)73:6<1721::aid-cncr2820730628>3.0.co;2-w.
It has been suggested that tumorigenesis of the germ cell tumor of the testis includes abnormal and developmentlike differentiation of primordial germ cells to several mature type tumors.
To clarify roles of protooncogenes in the unique tumorigenic mechanism in the human germ cell tumor, the authors examined the expression of 15 protooncogenes in human primary germ cell tumors of the testis with Northern blot analyses.
Fifteen (94%) of 16 seminomas and 5 (83%) of 6 embryonal carcinomas had a significant levels of N-myc expression, whereas they did not express two receptor type protooncogenes, c-erbB-1 and c-erbB-2. In contrast, some immature teratomas had a high level of c-erbB-1 expression, and an advanced case showed a significant level of c-erbB-2 expression. Immature teratomas did not show N-myc expression. Higher levels of c-mos expression were observed in several cases of seminomas and embryonal carcinomas. Expression of c-Ki-ras or N-ras was observed in all histologic subgroups and normal testes.
A significant level of N-myc expression may be essential for undifferentiated tumors including seminoma and embryonal carcinoma, whereas c-erbB-1 and possibly c-erbB-2 may have important roles in the differentiated tumors such as immature teratoma. These results suggest that some of the protooncogene expression may be switched critically during the differentiation from seminomas or embryonal carcinomas to the more differentiated-type tumor.
有研究表明，睾丸生殖细胞肿瘤的发生包括原始生殖细胞向几种成熟型肿瘤的异常和类似发育的分化。
为了阐明原癌基因在人类生殖细胞肿瘤独特致瘤机制中的作用，作者通过Northern印迹分析检测了15种原癌基因在人类原发性睾丸生殖细胞肿瘤中的表达。
16例精原细胞瘤中有15例（94%）和6例胚胎癌中有5例（83%）N-myc表达水平显著，而它们不表达两种受体型原癌基因c-erbB-1和c-erbB-2。相反，一些未成熟畸胎瘤c-erbB-1表达水平较高，1例晚期病例c-erbB-2表达水平显著。未成熟畸胎瘤未显示N-myc表达。在几例精原细胞瘤和胚胎癌中观察到较高水平的c-mos表达。在所有组织学亚组和正常睾丸中均观察到c-Ki-ras或N-ras的表达。
N-myc的显著表达水平可能对包括精原细胞瘤和胚胎癌在内的未分化肿瘤至关重要，而c-erbB-1以及可能的c-erbB-2可能在未成熟畸胎瘤等分化肿瘤中起重要作用。这些结果表明，在从精原细胞瘤或胚胎癌向更分化型肿瘤的分化过程中，一些原癌基因的表达可能会发生关键变化。
