Expression and biological functions of inhibitor of growth family member 4 in endometrial cancer
ZHANG Ting
WEI Yuan
LAI Mengjie
LI Junying
CHEN Chen
DU Yanmin
GUO Yongzhen
ZENG Xianxu
Abstract：Objective To investigate the expression of inhibitor of growth family member 4(ING4)in endometrial cancer(EC)and its effect on the biological functions of cancer cells.Methods A total of 138 endometrial tissue specimens were collected,including 30 normal endometrial(NE),31 endometrial hyperplasia without atypia(EHA),30 atypical endometrial hyperplasia(EAH),and 47 EC tissues.The protein expression of ING4,tumor protein p53(p53),cyclin-dependent kinase inhibitor 1A(p21),and cyclin-dependent kinase inhibitor 2A(p16)was detected by immunohistochemistry.Stable ING4-overexpressing cell lines(Ad-ING4 group)and negative control cell lines(NC group)were established in Ishikawa and HEC-1B cells via lentiviral transfection.The mRNA expression levels of ING4,p53,cysteine-containing aspartate-specific protease-3(CASP3),B-cell lymphoma-2(Bcl-2),and Bcl-2-associated X protein(Bax)were measured by quantitative real-time PCR,while the protein expression levels of ING4,p53,p21,p16,CASP3,Bcl-2,Bax,signal transducer and activator of transcription 3(STAT3),and its phosphorylated form(p-STAT3)were evaluated by Western blot.Cell proliferation,migration,and invasion were assessed using the Cell Counting Kit-8(CCK-8)assay,colony formation assay,wound healing assay,and Transwell invasion assay.Apoptosis and cell cycle distribution were analyzed by flow cytometry.A subcutaneous xenograft tumor model was established in nude mice using ING4-overexpressing HEC-1B cells to observe the effect of ING4 overexpression on in vivo tumor growth.Results In EC tissues,the expression level of ING4 protein(mean optical density:0.288±0.056)was significantly lower than that in NE(0.480±0.077),EHA(0.506±0.084),and EAH(0.406±0.096)tissues(P＜0.001).Furthermore,ING4 expression showed a significant positive correlation with the expression ofp21(r=0.353,P=0.015)and p 16(r=0.451,P=0.002).In cellular experiments,compared with the NC group,the Ad-ING4 group of Ishikawa and HEC-1B cells exhibited inhibited proliferation,migration,and invasion capabilities.Specifically,EC cells in the Ad-ING4 group showed significantly reduced proliferative activity(72 h,96 h),colony formation ability,wound healing rate,and the number of Transwell invading cells,along with an increased proportion of G1-phase cells and early apoptotic cells.In the Ad-ING4 group,the p53/p21/p16 signaling pathway was activated,CASP3 expression was upregulated,the Bax/Bcl-2 ratio increased,while p-STAT3 protein expression was inhibited.In vivo animal experiments demonstrated that the subcutaneous xenograft tumor volume in the Ad-ING4 group was significantly smaller than that in the NC group[(89.00±7.55)mm3 vs.(206.70±8.51)mm3,P＜0.01],and the protein expression levels of ING4,p53,and p16 in the tumor tissues were higher.Conclusion ING4 is downregulated in EC.Its overexpression effectively inhibits tumor cell proliferation,invasion,and in vivo tumorigenesis by activating the p53/p21/p16 pathway,promoting apoptosis,and inhibiting STAT3 phosphorylation,suggesting that ING4 possesses tumor-suppressive functions.
Keywords：endometrial cancerinhibitor of growth family member 4biological functionsignal transducer and activator of transcription 3
Publication Date：2026-01-28
Online Publishing Date：2026-03-18(First online date of this platform, not the publication date of the document)
Pages：8( 1-8 )