Department of Gastrointestinal Surgery, The First Affiliated Hospital of Ningbo University, Ningbo, Zhejiang, China.
Kaohsiung J Med Sci. 2023 Nov;39(11):1087-1095. doi: 10.1002/kjm2.12756. Epub 2023 Sep 19.
As a transcriptional factor, the Forkhead box (FOX) gene family is closely connected with apoptosis, proliferation, and other cellular processes. FOXD2, as one descendant of the FOX gene family, has been mentioned in many articles to show a high expression in several cancers. However, whether FOXD2 has a connection with gastric adenocarcinoma remains an unanswered question. Expression of FOXD2 and IQGAP3 in gastric adenocarcinoma was evaluated by bioinformatics analysis, which was further detected by real-time quantitative PCR (qRT-PCR) and western blot. The downstream target genes of FOXD2 were also mined by bioinformatics analysis. Pathway enrichment analysis was then performed on the target genes. Chromatin immunoprecipitation assay (ChIP) and dual-luciferase reporter assay were conducted to validate the regulatory relationship between FOXD2 and its downstream target gene IQGAP3. Methyl thiazolyl tetrazolium assay (MTT), combined with cell colony formation assay, was employed to assess the effect of FOXD2 and IQGAP3 on the proliferation of gastric adenocarcinoma cells. Intracytoplasmic Ca concentration was measured by Fluo-3 fluorescence staining. FOXD2 showed a high expression in gastric adenocarcinoma tissues and cells, and FOXD2 silencing considerably attenuated gastric adenocarcinoma cell proliferation. IQGAP3, a downstream target gene of FOXD2, had a positive connection with the expression of FOXD2. The binding relationship between FOXD2 and the promoter region of IQGAP3 was further verified by ChIP and dual-luciferase reporter assays. The results of cell function experiments indicated that FOXD2 could promote gastric adenocarcinoma cell proliferation by transcriptionally activating IQGAP3 to induce an increase in intracellular Ca level. This study confirmed that FOXD2 increased intracellular Ca level through transcriptional activation of IQGAP3, which in turn propelled the proliferation of gastric adenocarcinoma cells, revealing the considerable significance of FOXD2 in the development of gastric adenocarcinoma.
作为转录因子，叉头框（FOX）基因家族与细胞凋亡、增殖等过程密切相关。FOXD2 作为 FOX 基因家族的一个后裔，在许多文章中都被提到在几种癌症中高表达。然而，FOXD2 是否与胃腺癌有关仍然是一个悬而未决的问题。通过生物信息学分析评估 FOXD2 和 IQGAP3 在胃腺癌中的表达，并用实时定量 PCR（qRT-PCR）和 Western blot 进一步检测。通过生物信息学分析挖掘 FOXD2 的下游靶基因。然后对靶基因进行通路富集分析。通过染色质免疫沉淀试验（ChIP）和双荧光素酶报告基因试验验证 FOXD2 与其下游靶基因 IQGAP3 之间的调控关系。噻唑蓝（MTT）法与细胞集落形成实验相结合，评估 FOXD2 和 IQGAP3 对胃腺癌细胞增殖的影响。通过 Fluo-3 荧光染色测量细胞内 Ca 浓度。FOXD2 在胃腺癌组织和细胞中高表达，FOXD2 沉默显著抑制胃腺癌细胞增殖。IQGAP3 是 FOXD2 的下游靶基因，与 FOXD2 的表达呈正相关。ChIP 和双荧光素酶报告基因实验进一步验证了 FOXD2 与 IQGAP3 启动子区域的结合关系。细胞功能实验结果表明，FOXD2 通过转录激活 IQGAP3 促进胃腺癌细胞增殖，从而导致细胞内 Ca 水平升高。本研究证实，FOXD2 通过转录激活 IQGAP3 增加细胞内 Ca 水平，进而促进胃腺癌细胞增殖，揭示了 FOXD2 在胃腺癌发生发展中的重要意义。
