Figure 6

Comparative analysis of testis cancer-associated genes with genes the pre-pubertal Spga and Sertoli cells- specific gene sets. (A) Comparative analysis of gene transcripts enriched or attenuated in rat Spga and Sertoli cells at 9 and 22 dpp and of their human orthologs detected in several microarray studies of type II testicular germ cell tumors (TGCT). The orthologues of transcripts shown by different studies [69–76] to be enriched in TGCT were identified in the gene clusters defined in Figure 2. of Pairwise comparison between gene clusters reveals the relative enrichment or attenuation those orthologue transcripts as they are more (red) equally (white) or less (blue) abundant than expected in a random association. As an example, 133 transcripts orthologuous to genes over-expressed in TGCT[69–76] are enriched in S9 versus S22, whereas randomly 52 would be expected. The blue to red scale shows the statistical significance of enrichment or attenuation in the various clusters of genes was calculated using a Gaussian hyper-geometric test (Fischer exact probability test). (B) Genes in (A) detected in at least two independent TGCT studies, shown as a Venn diagram for the gene sets up-regulated at 9 dpp vs 22 dpp in Spga and Sertoli cells. (C) Quantitative assessment of pre-pupertal Spga and Sertoli cells gene expression for testis cancer-associated genes. Expression of protein phosphatase 1 regulatory subunit 1A (ppp1r1A), and of midkine (mdk) in pre-pubertal (9 dpp) and pubertal (22 dpp) spermatogonia and Sertoli cells (G9, G22, S9, S22, respectively) was quantified by real time RT-PCR. Values shown are normalized to two housekeeping genes ubc (right hand side) and ps9 (left hand side), respectively. Shown are the mean values (± SEM) from the 3 distinct cell preparations, for which genome-wide analysis by hybridization to a high density array is shown in Figure 2.