Chromogranin A

Chromogranin A (CgA) is an acidic hydrophilic protein mainly present in neuroendocrine cells. It can regulate the aggregation and secretion of neurotransmitters and peptide hormones, and can be hydrolyzed to form active substances such as angiostatin, pancreastatin, and catestatin to participate in various life activities. In clinical practice, CgA is an essential diagnostic biomarker for neuroendocrine neoplasm (NEN). It is often used in combination with Syn for differential diagnosis of various NENs such as gastro-entero-pancreatic NEN, small cell lung cancer, and pituitary adenoma, and the addition of Ki-67 can distinguish between neuroendocrine tumor (NET) and neuroendocrine cancer (NEC). Moreover, the high expression of CgA is closely related to tumor growth, metastasis, and recurrence, which may be because some active substances formed by CgA can promote proliferation and metastasis of cancer cells through autocrine or paracrine pathways. In addition, CgA can be expressed in some liver cancer, colorectal cancer, and prostate cancer, speculated that the tumor has undergone neuroendocrine differentiation, which suggests poor prognosis for patients.