Cui Zhi, Sun Shiqun, Li Jia, Li Jianing, Sha Tong, He Jie, Zuo Linjing
The Third Department of Oral and Maxillofacial Surgery, Hospital of Stomatology, Jilin University, Changchun, Jilin, China.
Department of Prosthodontics, Hospital of Stomatology, Jilin University, Changchun, Jilin, China.
Curr Cancer Drug Targets. 2022;22(9):771-783. doi: 10.2174/1568009622666220406104732.
Inhibitor of growth 4 (ING4) level was reported to be decreased in head and neck squamous cell carcinoma (HNSC) tissue, however, it is unknown whether and how ING4 participates in regulating the development of oral squamous cell carcinoma (OSCC).
This study aimed to investigate the role and mechanism of ING4 in OSCC.
ING4 was forced to up- or down-regulated in two OSCC cell lines, and its effects on the malignant behavior of OSCC cells were investigated in vitro. The ubiquitination level of NF-kB p65 in ING4 upregulated cells was measured by co-immunoprecipitation. Moreover, the effects of ING4 on the methylation level of ALDH1A2 were evaluated by methylation-specific polymerase chain reaction (MSP) assay. The role of ING4 in OSCC growth in vivo was observed in nude mice.
Our results showed that the expression of ING4 in OSCC cell lines was lower than that in normal oral keratinocyte cells. In vitro, ING4 overexpression inhibited the proliferation, migration, and invasion of OSCC cell lines and ING4 silencing exhibited opposite results. We also demonstrated that ING4 overexpression promoted the ubiquitination and degradation of P65 and reduced DNA methyltransferase 1 (DNMT1) expression and Aldehyde dehydrogenase 1A2 (ALDH1A2) methylation. Moreover, overexpression of p65 rescued the suppression of malignant behavior, induced by ING4 overexpression. In addition, ING4 negatively regulated the growth of OSCC xenograft tumors in vivo.
Our data evidenced that ING4 played a tumor-repressing role in OSCC in vivo and in vitro via NF-κB/DNMT1/ALDH1A2 axis.
有报道称头颈部鳞状细胞癌（HNSC）组织中生长抑制因子4（ING4）水平降低，然而，ING4是否以及如何参与调节口腔鳞状细胞癌（OSCC）的发展尚不清楚。
本研究旨在探讨ING4在OSCC中的作用及机制。
在两种OSCC细胞系中强制上调或下调ING4，体外研究其对OSCC细胞恶性行为的影响。通过免疫共沉淀法检测ING4上调细胞中NF-κB p65的泛素化水平。此外，通过甲基化特异性聚合酶链反应（MSP）分析评估ING4对醛脱氢酶1A2（ALDH1A2）甲基化水平的影响。在裸鼠体内观察ING4对OSCC生长的作用。
我们的结果显示，ING4在OSCC细胞系中的表达低于正常口腔角质形成细胞。在体外，ING4过表达抑制了OSCC细胞系的增殖、迁移和侵袭，而ING4沉默则表现出相反的结果。我们还证明，ING4过表达促进了P65的泛素化和降解，并降低了DNA甲基转移酶1（DNMT1）的表达和醛脱氢酶1A2（ALDH1A2）的甲基化。此外，p65的过表达挽救了ING4过表达诱导的恶性行为抑制。此外，ING4在体内负向调节OSCC异种移植瘤的生长。
我们的数据证明，ING4在体内和体外通过NF-κB/DNMT1/ALDH1A2轴在OSCC中发挥肿瘤抑制作用。
