Gynecology Department, Renmin Hospital of Wuhan University, Wuhan, China.
Reproductive Medicine Center, Renmin Hospital of Wuhan University, Wuhan, China.
PLoS One. 2023 Aug 18;18(8):e0290462. doi: 10.1371/journal.pone.0290462. eCollection 2023.
Mixed pedigree kinase 4 (MLK4) is a member of the serine/threonine kinases mixed pedigree kinase (MLKs) family. Few reports on immune-related targets in Cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC), and the role of MLK4 in cervical cancer remains to be studied. The expression of MLK4 in CESC was analyzed by TCGA database containing 306 CESC tissues and 3 peritumoral tissue samples, and the effect of MLK4 on immune invasion was evaluated using the Deseq2 package(Benjamini-Hochberg corrected p-value < 0.05 and log2 fold change ≥|2|). Tissue microarray was used to verify the expression of MLK4 in CESC patients, and it was found that MLK4 was significantly overexpressed in CESC, and significantly correlated with WHO grade. Multiple analysis algorithms revealed that the high expression of MLK4 was negatively correlated with immune cell infiltration in CESC. Analysis showed that MLK4 expression was negatively correlated with the infiltration of various immune cells including CD8+T cells, and MLK4 mRNA expression was positively correlated with immune checkpoints PD-L1,CTLA4, LAG3, and negatively correlated with immune promotion genes CD86 and CD80. Furthermore, vitro assays were performed to investigate the biological characteristics of MLK4 in C33A cells. The EDU and transwell assays demonstrated that the decrease in MLK4 expression in C33A cells resulted in a decrease in cell proliferation and invasion. The silencing of MLK4 resulted in a significant increase in the expression of inflammatory cytokines IL-1β(p<0.05), TNF-α(p<0.01), and IL-6 (p<0.05). The results of cell assays indicate that knocking down MLK4 would inhibit the expression of established biochemical markers CEA, AFP and HCG. Hence, it is plausible that MLK4 could potentially exert a significant influence on the development and progression of Cervical cancer.
混合谱系激酶 4（MLK4）是丝氨酸/苏氨酸激酶混合谱系激酶（MLKs）家族的成员。关于宫颈鳞状细胞癌和宫颈内膜腺癌（CESC）中的免疫相关靶点的报道很少，MLK4 在宫颈癌中的作用仍有待研究。通过包含 306 个 CESC 组织和 3 个肿瘤旁组织样本的 TCGA 数据库分析 CESC 中 MLK4 的表达，并使用 Deseq2 包评估 MLK4 对免疫浸润的影响（Benjamini-Hochberg 校正的 p 值<0.05，对数倍数变化≥|2|）。使用组织微阵列验证 MLK4 在 CESC 患者中的表达，发现 MLK4 在 CESC 中明显过表达，且与 WHO 分级显著相关。多分析算法显示，MLK4 的高表达与 CESC 中的免疫细胞浸润呈负相关。分析表明，MLK4 的表达与包括 CD8+T 细胞在内的各种免疫细胞的浸润呈负相关，MLK4 mRNA 表达与免疫检查点 PD-L1、CTLA4、LAG3 呈正相关，与免疫促进基因 CD86 和 CD80 呈负相关。此外，在 C33A 细胞中进行了 vitro 测定以研究 MLK4 的生物学特性。EDU 和 Transwell 测定表明，C33A 细胞中 MLK4 表达的降低导致细胞增殖和侵袭减少。MLK4 的沉默导致炎症细胞因子 IL-1β（p<0.05）、TNF-α（p<0.01）和 IL-6（p<0.05）的表达显著增加。细胞测定的结果表明，敲低 MLK4 会抑制已建立的生化标志物 CEA、AFP 和 HCG 的表达。因此，MLK4 可能对宫颈癌的发生和发展产生重大影响。
