Significance of cancer testis-associated antigens ( SPAG9 and FBXO39) in colon cancer

Indian J Cancer. 2021 May 11. doi: 10.4103/ijc.IJC_873_19. Online ahead of print.


Background: Cancer testis antigens (CTA) are normally expressed in immune privileged tissues such as the testis. They are considered tumor-associated antigens because they are specifically expressed in different cancers. Their distinct nature rendered them appealing targets for cancer diagnosis, prognosis. and immunotherapy. We aimed to identify the association of two CTA genes with colon cancer (CC) in a cohort of Egyptian patients.

Methods: We measured the relative gene expression levels of two CTAs: SPAG9 and FBXO39 in colonic tumor tissue and adjacent normal-appearing mucosa in 50 newly diagnosed colon cancer patients by real-time reverse transcription polymerase chain reaction. Gene expression was also studied in relation to demographic and pathological criteria.

Results: SPAG9 and FBXO39 were overexpressed in 22% and 40% of cases, respectively. Overexpression of both genes was evident in 14% of cases. We report the significant expression of FBXO39 (P < 0.01) in tumor tissue compared to normal tissue. SPAG9 was significantly increased in large sized tumors compared to smaller sized tumors. Otherwise, there was no significant association between gene expression and the evaluated clinicopathological features (P > 0.05).

Conclusions: SPAG9 and FBXO39 are possible CC diagnostic biomarkers. Further studies are warranted to validate our findings.

Keywords: Cancer testis antigens; colon cancer; gene expression; immunotherapy; real time reverse transcription polymerase chain reaction.