胃腺癌的详细分子特征鉴定

胃癌是癌症死亡的主要原因之一，但其分子和临床特征的分析由于组织学和病原学的异质性而变得错综复杂。作为癌症基因组图集（ The Cancer Genome Atlas ， TCGA）计划的一部分，科学家们对295位原发性胃腺癌患者进行了详细的分子鉴定。他们提出一种分子分类方法，将胃癌分为四种亚型：（1） EB病毒阳性型肿瘤，其分子特征表现为周期性的PIK3CA基因突变、极度DNA甲基化，以及JAK2、CD274（又称PD-L1）和PDCDILG2（又称PD-L2）基因扩增；（2）微卫星不稳定型肿瘤，显示出较高的基因突变率，其中包括编码靶向致癌信号蛋白的基因突变；（3）基因组稳定型肿瘤，富含广泛的组织学变异和RHOA基因突变，或者是涉及与RHO家族GTP酶活性蛋白的融合；（4）染色体不稳定型肿瘤，表现出显著的非整倍体和酪氨酸激酶受体的局部扩增。胃癌亚型鉴定为胃癌患者分期和实验性靶向治疗指明了方向。

A novel male-specific SET domain-containing gene setdm identified from extra microchromosomes of gibel carp males

Various genes have been screened on extra chromosomes, but their molecular characterization, expression pattern and biological function are still unclear. Here, we utilized a male-specific sequence of polyploid gibel carp （Carassius gibelio） to identify a novel male-specific SET （Su（var）3-9, Enhancer- of-zeste, Trithorax） domain-containing gene setdm on extra microchromosomes of gibel carp males. And setdm was characterized in molecule and expression aspects, in which its expression was specific to testis, and had relative high transcription during middle/late stages of testis development. Moreover, prominent expression of Setdm in spermatogenic cells was observed in testis through immunofluorescence co-localization analysis. These results suggest that biological function of setdrn might be related to testis development and spermatogenesis of gibel carp. Additionally, the homeologous gene setdmf of setdm, was also characterized, and its expression was gonad-specific, in which its expressed product was detected to mainly distribute in gametogenic cells of testis and ovary, and to have dynamic expression pattern similar to that of setdm. Based on the current results, we propose that the novel male-specific setdm on extra microchromosomes might be functional divergence gene of the gonad-specific setdmf. Therefore, these findings will help us to further understand evolutionary fate and functional role of genes on extra microchromosomes.