57 genes associated with prognostic outcome in testis cancer

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Figure 1. Immunohistochemical staining of CLCN7 shows high (left) and low (right) expression in testis cancer samples.
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Figure 2. Immunohistochemical staining of IFT52 shows high (left) and low (right) expression in Testis cancer samples.

Testicular cancer is a rare type of cancer. Most testis cancers are curable, even at an advanced stage. The cancer can be divided into essentially two categories: Seminoma and Non-seminomatous germ cell tumors. Based on transcriptomics data and clinical metadata we have been able to determine 57 genes associated with either favorable or unfavorable prognosis in testis cancer.

Nearly all (95%) testis cancers originate from germ cells. Out of all cancers in males, testis cancer accounts for approximately one percent. Testis cancer is grouped into two categories: Seminoma and non-seminomatous germ cell tumors. The histology of seminomas show rather large tumor cells with distinct borders with centralized nuclei and one or two distinct nucleoli. The tumor stroma is characterized of a fibrovascular network with a thin septa of collagen and a variable amount of immune cells. The non-seminoma cancers, the embryonal carcinomas, exhibit more irregularities in the tumor cells, they can be large with irregular nuclei and cell borders are more difficult to distinguish. Areas of necrosis, fibrosis and hemorrhage can often be found. Knowing the histology of the different testis tumors is of importance for diagnostics. Using microscopy and histological evaluation is a key feature to determine tumor growth and absence or presence of metastatic cancer cells into the vascular or lymphatic system.

To analyze the testis cancer proteome we used the Cancer Genome Atlas TCGA database to evaluate the transcriptomics data and antibody based protein data. According to that data, 57 genes were suggested as prognostic markers based on transcriptomics and clinical data from 134 patients; 42 genes were associated with unfavorable prognosis and 15 genes were associated with favorable prognosis.

The CLCN7 gene product belongs to the CLC chloride channel family of proteins. It has been shown that this gene is associated with an unfavorable prognosis for testis cancer.Immunohistochemical using an antibody targeting CLCN7 shows differential expression pattern in testis cancer samples (Figure 1).

The IFT52 gene encodes a conserved proline-rich protein that is a component of the intraflagellar transport-B (IFT-B) core complex. The encoded protein is essential for the integrity of the IFT-B core complex, and for biosynthesis and maintenance of cilia. It has been shown that this gene is associated with a favorable outcome. Immunohistochemical staining using an antibody targeting IFT52 shows a cytoplasmic staining pattern in testis cancer samples (Figure 2).

Explore the Testis Cancer Proteome and search for your gene of interest in our Pathology Atlas!

References and links

Uhlén M et al, 2017. A pathology atlas of the human cancer transcriptome. Science.
PubMed: 28818916 DOI: 10.1126/science.aan2507

Histology dictionary - Testis Cancer

Emil Lindström