Gangliosides are a class of important glycosphingolipids containing sialic acid that are widely distributed on the outer surface of cells and are abundantly distributed in brain tissue. Disialoganglioside with three glycosyl groups (GD3) and disialoganglioside with two glycosyl groups (GD2) are markedly increased in pathological conditions such as cancers and neurodegenerative diseases. GD3 and GD2 were found to play important roles in cancers by mediating cell proliferation, migration, invasion, adhesion, angiogenesis and in preventing immunosuppression of tumors. GD3 synthase (GD3S) is the regulatory enzyme of GD3 and GD2 synthesis, and is important in tumorigenesis and the development of cancers. The study of GD3S as a drug target may be of great significance for the discovery of new drugs for cancer treatment. This review will describe the gangliosides and their roles in physiological and pathological conditions; the roles of GD3 and GD2 in cancers; the expression, functions and mechanisms of GD3S, and its potential as a drug target in cancers.

ObjectiveTo investigate the diagnostic value of ultrasound on patients with papillary thyroid carcinoma(PTC) coexisted with Hashimoto thyroiditis(HT).Methods The preoperative ultrasonography data of 2144 cases with PTC from January 2006 to December 2011 who treated with operation and diagnosed by pathology were analyzed retrospectively.Among them,265 cases coexisted with HT (PTC coexisted with HT group),1879 cases were not coexisted with HT (non-PTC coexisted with HT group).ResultsMost of the cancerous nodes in two groups exhibited in the ultrasonographic performance just like irregular shape,unclear boundary and so on (P ＞ 0.05).Most of the cancerous nodes in non-PTC coexisted with HT group exhibited hypoechoic nodules with microcalcifications,those in PTC coexisted with HT group exhibited various internal echoes with mainly microcalcifications,and the coarse calcification occupied a certain proportion(P＜ 0.01 ).The cancerous nodes in PTC coexisted with HT group were not rich in blood flow compared with non-PTC coexisted with HT group,but mostly exhibited blood disorders.When compared with non-PTC coexisted with HT group,the rate of ultrasound diagnosis in PTC coexisted with HT group was lower [ 52.8 ％( 140/265 ) vs.75.0 ％ (1409/1879),P ＜ 0.01 ],and the false positive rate in lymph node was higher [84.0％(487/580) vs.74.8％ (77/103)] (P ＜0.05).ConclusionsThe nodules are malignant when they appear as hypoechoic solid nodules,have unclear boundary and have microcalcifications should be highly suspected.The hyperechoic solid nodules or coarse calcification nodules should also be awared and taken further observation of the characteristics around the echoes and the internal blood flow,making comprehensive analysis to determine whether it could be malignant transformation and try best to reduce the misdiagnosis and missed diagnosis rates of this disease.