Table 2.
Differences in the transcript levels of the examined genes between the colorectal adenoma/carcinoma and the non-neoplastic tissue in the Irish and the Czech CRA/CRC patients (this study), and comparison with data from the TCGA patient cohorts.
| Gene Name | Discovery (Irish Cohort, n = 62; 40 CRA and 22 CRC) |
Validation (Czech Cohort, N = 105 CRC) Carcinoma Expression (p-Value) |
TCGA (COAD/READ) Carcinoma Expression |
|
|---|---|---|---|---|
| Adenoma Expression (p-Value) | Carcinoma Expression (p-Value) | |||
| GPX1 | NS | NS | ↑ (<0.001) | NS/NS |
| GPX2 | ↑ (<0.001) | ↑ (0.023) | ↑ (<0.001) | ↑/↑ |
| GPX3 | ↓ (<0.001) | ↓ (<0.001) | ↓ (<0.001) | ↓/↓ |
| GPX4 | NS | ↑ (0.039) | NS | NS/NS |
| SELENOF | NS | NS | NS | NS/NS |
| SELENOH | ↑ (<0.001) | NS | ↑ (<0.001) | NS/NS |
| SELENOK | NS | ↓ (0.015) | ↓ (<0.001) | NS/NS |
| SELENON | NS | NS | ↓ (<0.001) | NS/NS |
| SELENOP | ↓ (<0.001) | ↓ (0.001) | ↓ (<0.001) | ↓/↓ |
| SELENOS | ↓ (<0.001) | ↓ (<0.001) | ↓ (<0.001) | NS/NS |
| SELENOW | NS | NS | NS | NS/NS |
| SEPHS2 | ↓ (<0.001) | ↓ (0.002) | ↓ (<0.001) | NS/NS |
| TXNRD1 | NS | NS | NS | NS/NS |
| TXNRD2 | NS | NS | NS | NS/NS |
| TXNRD3 | ↑ (<0.001) | ↑ (0.003) | ↑ (<0.001) | ↑/↑ |
| SELENBP1 | NS | ↓ (<0.001) | ↓ (<0.001) | ↑/↑ |
| SOD2 | NS | ↑ (0.036) | ↑ (<0.001) | NS/NS |
Abbreviations: ↑ = higher expression in the neoplastic compared to the normal tissue, ↓ = lower expression in the neoplastic compared to the normal tissue, NS = not significant, TCGA = The Cancer Genome Atlas (https://cancergenome.nih.gov/), COAD = colon adenocarcinoma, and READ = rectum adenocarcinoma. For the seventeen genes tested in the Irish and the Czech studies, only SELENOF, SELENOW, TXNRD1, and TXNRD2 were not significantly different in at least in one of the neoplasm groups. Genes significant in all three Irish and Czech sample sets (GPX2, GPX3, SELENOP, SELENOS, SEPHS2, and TXNRD3) are marked by a dark background. p-values are in brackets. TCGA data: Analysis done on the TCGA tumor-normal data, using the GEPIA (Gene Expression Profiling Interactive Analysis) tool (http://gepia.cancer-pku.cn/about.html; Tang et al. Nucleic Acids Res. 2017; 45(W1): W98–W102).