Cheng Kim Jun, Mohamed Elsa Haniffah Mejia, Syafruddin Saiful Effendi, Ibrahim Zaridatul Aini
Department of Pharmacology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
UKM Medical Molecular Biology Institute, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, 56000, Kuala Lumpur, Malaysia.
J Cell Commun Signal. 2023 Mar;17(1):189-208. doi: 10.1007/s12079-022-00681-3. Epub 2022 May 9.
Pathogenic infections have significant roles in the pathogenesis of colorectal cancer (CRC). These infections induce the secretion of various damage-associated molecular patterns (DAMPs) including interleukin-1 alpha (IL-1α) and high mobility group box-1 (HMGB1). Despite their implication in CRC pathogenesis, the mechanism(s) that modulate the secretion of IL-1α and HMGB1, along with their roles in promoting CRC tumourigenesis remain poorly understood. To understand the secretory mechanism, HT-29 and SW480 cells were stimulated with infectious mimetics; polyinosinic:polycytidylic acid [Poly(I:C)], lipopolysaccharide (LPS) and pro-inflammatory stimuli; tumour necrosis factor-alpha (TNF-α). IL-1α and HMGB1 secretion levels upon stimulation were determined via ELISA. Mechanism(s) mediating IL-1α and HMGB1 secretion in CRC cells were characterized using pharmacological inhibitors and CRISPR-Cas9 gene editing targeting relevant pathways. Recombinant IL-1α and HMGB1 were utilized to determine their impact in modulating pro-tumourigenic properties of CRC cells. Pharmacological inhibition showed that Poly(I:C)-induced IL-1α secretion was mediated through endoplasmic reticulum (ER) stress and RIPK1 signalling pathway. The secretion of HMGB1 was RIPK1-dependent but independent of ER stress. RIPK1-targeted CRC cell pools exhibited decreased cell viability upon Poly(I:C) stimulation, suggesting a potential role of RIPK1 in CRC cells survival. IL-1α has both growth-promoting capabilities and stimulates the production of pro-metastatic mediators, while HMGB1 only exhibits the latter; with its redox status having influence. We demonstrated a potential role of RIPK1-dependent signalling pathway in mediating the secretion of IL-1α and HMGB1 in CRC cells, which in turn enhances CRC tumorigenesis. RIPK1, IL-1α and HMGB1 may serve as potential therapeutic targets to mitigate CRC progression.
致病性感染在结直肠癌（CRC）的发病机制中起着重要作用。这些感染会诱导包括白细胞介素-1α（IL-1α）和高迁移率族蛋白B1（HMGB1）在内的多种损伤相关分子模式（DAMPs）的分泌。尽管它们与CRC发病机制有关，但调节IL-1α和HMGB1分泌的机制及其在促进CRC肿瘤发生中的作用仍知之甚少。为了了解分泌机制，用感染模拟物；聚肌苷酸:聚胞苷酸[Poly（I:C）]、脂多糖（LPS）和促炎刺激物；肿瘤坏死因子-α（TNF-α）刺激HT-29和SW480细胞。通过酶联免疫吸附测定（ELISA）确定刺激后IL-1α和HMGB1的分泌水平。使用药理学抑制剂和靶向相关途径的CRISPR-Cas9基因编辑来表征CRC细胞中介导IL-1α和HMGB1分泌的机制。利用重组IL-1α和HMGB1来确定它们对调节CRC细胞促肿瘤特性的影响。药理学抑制表明，Poly（I:C）诱导的IL-1α分泌是通过内质网（ER）应激和RIPK1信号通路介导的。HMGB1的分泌依赖于RIPK1，但不依赖于ER应激。靶向RIPK1的CRC细胞池在Poly（I:C）刺激后细胞活力降低，表明RIPK1在CRC细胞存活中具有潜在作用。IL-1α具有促进生长的能力，并刺激促转移介质的产生，而HMGB1仅表现出后者；其氧化还原状态有影响。我们证明了RIPK1依赖性信号通路在介导CRC细胞中IL-1α和HMGB1分泌中的潜在作用，这反过来又增强了CRC的肿瘤发生。RIPK1、IL-1α和HMGB1可能作为减轻CRC进展的潜在治疗靶点。
