Elevated Human Chorionic Gonadotropin HCG Serum Level in Germ Cell Testicular Tumor

Abstract

Submit Manuscript | http://medcraveonline.com cancer diagnosis, determining prognosis, surveillance following curative surgery for cancer, Tumor markers are playing an increasingly important role in cancer detection and management.In case of testicular cancer diagnosis/case finding, staging, prognosis determination, alpha-fetoprotein (AFP), human chorionic gonadotropin (HCG), and lactate dehydrogenase (LDH) are recommended, they play an important role as serum tumor markers for in the staging and monitoring of germ cell tumors. 2But what the relationship between HCG serum levels and germ cell testicular tumors? Human chorionic gonadotropin (HCG)HCG is a glycoprotein hormone composed of two dissimilar subunits, α and β, joined noncovalently. It is produced by trophoblast tissue in pregnancy and trophoblast disease and in small amounts by certain poorly differentiated cancers. The α-subunit of HCG is similar to that of the pituitary glycoprotein hormones. It is produced principally by the trophoblastic cells of the placenta but may also be produced by nontrophoblastic tissues including normal pituitary and neoplastic cells.3 It is normal for non-pregnant women and men to make very small amounts of HCG, with blood levels less than 5mIU/ mL. If HCG is high in non-pregnant women or men, it may indicate cancer. 4 Where used in malignant causes as tumor marker which is secreted by some cancers including choriocarcinoma, endometrium, and ovarian carcinoma. HCG is elevated in most type of testicular cancer seminomas and non-seminoma germ cell testicular tumors.It has been found that HCG possesses a role in the angiogenic process in vivo and in vitro by increasing capillary formation and endothelial cell migration, also, hCG-induced neovascularization. HCG may regulate vascular neoformation through vascular endothelial growth factor (VEGF). 5HCG contains five acidic asparagines-linked sugar chains. These five sugar chains are derived by sialylation from three neutral oligosaccharides: two biantennary (N-1 and N-2) and one monoantennary (N-3) complex-type oligosaccharides. The malignant transformational change of the sugar moiety of HCG can be explained by an increase of a fucosyltransferas. 6 Which indicate that N-acetylglucosaminyltransferase IV (GnT-IV) is abnormally expressed in the malignant cells. There are independent variants of HCG, each produced by different cells with separate biological functions. Multiple molecular variants of HCG include intact HCG, nicked HCG (hCGn), free β-subunit HCG (hCGβ), nicked free β-subunit HCG (hCGβn), free α-subunit hCG (hCGα), and the β-core fragment hCG (hCGβcf). In addition, HCG is differentially glycosylated in various tissues, resulting in a range of molecular forms from hypoglycosylated to hyperglycosylated. So-called hyperglycosylated HCG (hCG-h) is probably the best known of these glycosylated variants, 8 each one of them sharing the common amino acid sequence but each differing in meric structure and carbohydrate side chain structure.Hcg that produced by trophoblast cells...

Glycan Analysis as Biomarkers for Testicular Cancer

“…Both subunits of hCG (37 kDa) are heavily glycosylated (Table 1) with one third of the molecular mass of hCG consisting of glycans [35]. Subunit α (92 amino acids) contains two N-glycans (Asn52 and Asn78) ( Figure 2a) and exhibits similarity with the follicle-stimulating hormone, luteinising hormone and thyroid-stimulating hormone [18,[36][37][38][39]. The larger subunit β (145 amino acids) contains two N-glycans (Asn13 and Asn30) and 4 O-glycans (Ser121, Ser127, Ser132 and Ser138) (Figure 2a).…”