The Study of the Expression of CGB1 and CGB2 in Human Cancer Tissues

Abstract

Human chorionic gonadotropin (hCG) is a well-known hormone produced by the trophoblast during pregnancy as well as by both trophoblastic and non-trophoblastic tumors. hCG is built from two subunits: α (hCGα) and β (hCGβ). The hormone-specific β subunit is encoded by six allelic genes: CGB3, CGB5, CGB6, CGB7, CGB8, and CGB9, mapped to the 19q13.32 locus. This gene cluster also encompasses the CGB1 and CGB2 genes, which were originally considered to be pseudogenes, but as documented by several studies are transcriptionally active. Even though the protein products of these genes have not yet been identified, based on The Cancer Genome Atlas (TCGA) database analysis we showed that the mutual presence of CGB1 and CGB2 transcripts is a characteristic feature of cancers of different origin, including bladder urothelial carcinoma, cervical squamous cell carcinoma, esophageal carcinoma, head and neck squamous cell carcinoma, ovarian serous cystadenocarcinoma, lung squamous cell carcinoma, pancreatic adenocarcinoma, rectum adenocacinoma, testis germ cell tumors, thymoma, uterine corpus endometrial carcinoma and uterine carcinosarcoma.