Chen Gun, Cong Linghua, Gu Chijiang, Li Ping
Department of Pathology, The Affiliated People's Hospital of Ningbo University, No. 251, Baizhang Street, Yinzhou District, Ningbo, 315000, China.
Department of Gastrointestinal Surgery, The Affiliated People's Hospital of Ningbo University, Ningbo, 315000, China.
J Bioenerg Biomembr. 2024 Dec;56(6):645-655. doi: 10.1007/s10863-024-10039-6. Epub 2024 Sep 30.
High IQ motif-containing GTPase activating protein 3 (IQGAP3) expression is considered to be associated with poor prognosis of colorectal cancer (CRC). However, its role in early-onset CRC (EOCRC) progress is unclear. The mRNA and protein levels of IQGAP3 and Parkin (PRKN) were examined by qRT-PCR and western blot. Cell proliferation, apoptosis and metastasis were determined by CCK8 assay, EdU assay, flow cytometry and transwell assay. ROS, MDA, GSH, Fe, ACSL4 and SLC7A11 levels were detected to assess cell ferroptosis. The interaction between PRKN and IQGAP3 was assessed by Co-IP assay and ubiquitination assay. Xenograft tumor models were constructed to explore the effect of PRKN and IQGAP3 on the tumorigenesis in vivo. IQGAP3 was upregulated, while PRKN was downregulated in EOCRC tissues and cells. IQGAP3 knockdown inhibited CRC cell proliferation, migration and invasion, while enhanced apoptosis and ferroptosis. PRKN ubiquitinated IQGAP3 to promote its degradation. PRKN overexpression suppressed CRC cell growth, metastasis and promoted ferroptosis, while these effects were reversed by upregulating IQGAP3. In animal study, upregulation of PRKN reduced CRC tumorigenesis by decreasing IQGAP3 expression in vivo. IQGAP3, ubiquitinated by PRKN, promoted EOCRC progression by enhancing cell proliferation, metastasis, repressing apoptosis and ferroptosis, which provided a novel target for EOCRC treatment.
含高智商基序的GTP酶激活蛋白3（IQGAP3）的表达被认为与结直肠癌（CRC）的不良预后相关。然而，其在早发性结直肠癌（EOCRC）进展中的作用尚不清楚。通过qRT-PCR和蛋白质印迹法检测IQGAP3和帕金蛋白（PRKN）的mRNA和蛋白质水平。通过CCK8法、EdU法、流式细胞术和Transwell法测定细胞增殖、凋亡和转移情况。检测活性氧（ROS）、丙二醛（MDA）、谷胱甘肽（GSH）、铁（Fe）、长链脂酰辅酶A合成酶4（ACSL4）和溶质载体家族7成员11（SLC7A11）水平以评估细胞铁死亡情况。通过免疫共沉淀（Co-IP）法和泛素化试验评估PRKN与IQGAP3之间的相互作用。构建异种移植瘤模型以探究PRKN和IQGAP3对体内肿瘤发生的影响。在EOCRC组织和细胞中，IQGAP3表达上调，而PRKN表达下调。敲低IQGAP3可抑制CRC细胞的增殖、迁移和侵袭，同时增强凋亡和铁死亡。PRKN使IQGAP3泛素化以促进其降解。PRKN过表达可抑制CRC细胞生长、转移并促进铁死亡，而通过上调IQGAP3可逆转这些作用。在动物研究中，上调PRKN可通过降低体内IQGAP3表达来减少CRC肿瘤发生。被PRKN泛素化的IQGAP3通过增强细胞增殖、转移、抑制凋亡和铁死亡来促进EOCRC进展，这为EOCRC治疗提供了一个新靶点。
