Effects Of AIP Gene Mutations From A Han Chinese Pituitary Adenoma Cohort On Cell Proliferation

Background: Pituitary adenomas (PAs) account for15%of primary intracranialneoplasms and are the second most common type of intracranial tumor. The vastmajority of PAs are sporadic. However, a small proportion is characterized by a familialaggregation and has been well described in the setting of an endocrine tumor syndrome,such as multiple endocrine neoplasia type1(MEN1) and Carney complex (CNC), aswell as familial isolated PA (FIPA), in which pituitary tumors occur in multiplemembers of a single family in the absence of MEN1or CNC. FIPA was discovered toaccount for about2%of all adenomas. Studies suggest that aryl hydrocarbon receptorinteracting protein (AIP) gene mutation can explain about20%of FIPA. FIPA has maintypes of growth hormone adenoma or prolactin adenoma or mixed，age<40years, mostlymen and often a huge tumor volume. AIP mutations are also present in patients withsporadic pituitary adenomas. AIP gene is located at11q13and is considered to be tumorsuppressor gene, encodes AIP protein. C-terminal region of AIP protein plays animportant role in the predisposition to pituitary adenomas. AIP protein has interactionswith many factors and tetratricopeptide repeat(TPR) at C-terminal is the key structure.There is the first study on the Han Chinese FIPA family members and sporadic pituitarypatients AIP gene screening, finding several mutations disrupt the structure of TPR.These mutations are presumed pathogenic variants. Objective: To observe effects of AIP gene on cell proliferation and invasiveness and toverify whether AIP acts a tumor suppressor gene; to come to a preliminary conclusionwhether mutations in Han Chinese pituitary adenoma patients directly lead totumorigenesis.Methods: Transfect the plasmids containing the mutant and wild-type AIP gene intoHEK293T, GH3cells with transfection reagent; Observe transfection efficiency byco-transfection with EGFP plasmid; Verify protein expressed by AIP gene by WesternBlotting and immunofluorescence; Proliferation assay on cells transfected by the mutantand wild-type AIP gene and empty vector was accessed by cell counting kit-8(CCK-8);Observe invasiveness of cells by transwell co-culture invasion assay.Conclusions:1. AIP gene can inhibit cell proliferation.2. AIP gene may not affect cellinvasiveness.3.AIP gene mutations reported from a Han Chinese cohort may not havethe direct pathopoiesis in pituitary adenoma, there would be another pathogenicmutation or other causes in Han FIPA kindreds.