[Basic and translational research progress of gastrointestinal neuroendocrine neoplasmas]

Gastrointestinal neuroendocrine tumors are a group of highly heterogeneous tumors. Their incidences have increased in the Western countries as well as in Asia for years. In recent years, predominant progression has been made in the basic and translational studies on gastrointestinal neuroendocrine tumors. Gastric neuroendocrine neoplasmas are classified as four types: type I( occurs on the basis of autoimmune atrophic gastritis, type II( clinically manifests as multiple endocrine tumor type I( and Zollinger-Ellison syndrome, type III( is sporadic neuroendocrine neoplasmas, and type IIII( is neuroendocrine carcinoma. According to the location of primary tumor, intestinal neuroendocrine neoplasmas are classified as small intestine neuroendocrine neoplasmas and colorectal neuroendocrine neoplasmas. The latest finding shows that familial type I( gastric neuroendocrine neoplasmas exists homozygous missense mutation (c.2107C>T) of ATP4A gene. A number of researches focus on small intestine neuroendocrine neoplasmas recently. The chromosome instability, whole genome low methylation and abnormal expression of microRNA can be found in small intestine neuroendocrine neoplasmas. Part of them presents heterozygous mutations and loss of heterozygosity of CDKN1B gene. A recent study showed the heterozygous mutations of IPMK gene (c.990-993del) in familial small intestinal neuroendocrine neoplasmas. PROX1 and Annexin A1 may be involved in the malignant progression of rectal neuroendocrine neoplasmas via the Wnt pathway. The molecular mechanism of gastrointestinal neuroendocrine carcinoma is significantly different from gastrointestinal neuroendocrine tumors. The expression of mTOR, thymidylate synthase and PD-L1 protein, and gene mutation of BRAF V600E and KRAS have been exclusively found in gastrointestinal neuroendocrine carcinoma. The expression of thymidylate synthase, p27, p16, Gα15, PROX1 and Annexin A1 in gastrointestinal neuroendocrine neoplasmas is associated with the prognosis of these patients. Neurokinin A is a specific peripheral blood tumor biomarker for the prognosis and response to the treatment of patients with small intestinal neuroendocrine neoplasmas. INSL5 can be used as a unique biomarker for rectal neuroendocrine neoplasmas.