Effect of ubiquitin-specific proteinase 43 on ovarian serous adenocarcinoma and its clinical significance

Ovarian cancer stands as a highly aggressive malignancy. The core aim of this investigation is to uncover genes pivotal to the progression and prognosis of ovarian cancer, while delving deep into the intricate mechanisms that govern their impact. The study entailed the retrieval of RNA-seq data and survival data from the XENA database. Outliers were meticulously excluded in accordance with TCGA guidelines and through principal components analysis. The R package ‘deseq2’ was harnessed to extract differentially expressed genes. WGCNA was employed to prioritise these genes, and Cox regression analysis and survival analysis based on disease-specific time were conducted to identify significant genes. Immunohistochemistry validation was undertaken to confirm the distinct expression of USP43. Furthermore, the influence of USP43 on the biological functions of ovarian cancer cells was explored using techniques such as RNA interference, western blotting, scratch assays, and matrigel invasion assays. The examination of immune infiltration was facilitated via CIBERSORT. The study unearthed 5195 differentially expressed genes between ovarian cancer and normal tissue, comprising 3416 up-regulated and 1779 down-regulated genes. WGCNA pinpointed 204 genes most intimately tied to tumorigenesis. The previously undisclosed gene USP43 exhibited heightened expression in tumour tissues and exhibited associations with overall survival and disease-specific survival. USP43 emerged as a driver of cell migration (43.27 ± 3.91% vs 19.69 ± 1.94%) and invasion ability (314 ± 32 vs 131 ± 12) through the mechanism of epithelial mesenchymal transition, potentially mediated by the KRAS pathway. USP43 was also identified as a booster of CD4+ T memory resting cell infiltration, while concurrently reducing M1 macrophages within cancer, thereby fostering a milieu with relatively immune suppressive traits. Interestingly, USP43 demonstrated connections with epigenetically regulated-mRNAsi, although not with mRNAsi. This study underscores the role of USP43 in facilitating tumour migration and invasion. It postulates USP43 as a novel therapeutic target for ovarian cancer treatment. Ovarian cancer is the most deadly tumour among all gynecological tumours. Thus we tried to explore the relevant mechanism of ovarian cancer because its occurrence and development mechanism has not been fully elucidated. We used bioinformatics methods to perform differential gene analysis on ovarian cancer tissues and normal tissues, and used methods such as WGCNA and COX regression analysis to find the gene USP43 related to tumour development and prognosis. USP43 is a gene that has not been studied in ovarian cancer before. Through RNA interference technology, we found that it can promote the migration and invasion ability of ovarian cancer and promote epithelial-mesenchymal transition of ovarian cancer cells. In addition, this gene has also been proven to be related to tumour immunity and tumour stemness. These results indicate that USP43 can promote the tumorigenesis of ovarian cancer and can be used as a drug target.

卵巢癌是一种高侵袭性恶性肿瘤。本研究的核心目标为挖掘与卵巢癌进展及预后密切相关的关键基因，并深入解析调控这些基因发挥作用的复杂分子机制。研究从XENA数据库中获取了RNA测序（RNA-seq）数据与生存数据，依据癌症基因组图谱（TCGA）指南并通过主成分分析（PCA）严格剔除异常值。本研究借助R包‘DESeq2’提取差异表达基因，采用加权基因共表达网络分析（WGCNA）对这些基因进行优先级排序，并基于疾病特异性生存期开展Cox回归分析与生存分析，以筛选出具有统计学意义的关键基因。通过免疫组织化学（Immunohistochemistry）验证了USP43在组织中的差异表达情况；此外，本研究通过RNA干扰、蛋白质印迹（Western Blot）、划痕实验以及基质胶侵袭实验等技术手段，探究了USP43对卵巢癌细胞生物学功能的影响，并借助CIBERSORT算法分析肿瘤免疫浸润情况。本研究共筛选得到5195个卵巢癌组织与正常组织间的差异表达基因，其中上调基因3416个，下调基因1779个。经WGCNA分析，筛选出204个与肿瘤发生发展密切相关的核心基因。此前尚未在卵巢癌中被研究的USP43基因在肿瘤组织中呈高表达，且与患者总生存期及疾病特异性生存期显著相关。USP43可通过上皮间质转化（EMT）机制促进细胞迁移（迁移率分别为43.27±3.91%与19.69±1.94%）与侵袭能力（侵袭细胞数分别为314±32与131±12），其作用可能由KRAS通路介导。此外，USP43可促进静息CD4+记忆T细胞的肿瘤浸润，同时减少肿瘤内M1型巨噬细胞的浸润，进而构建出相对免疫抑制的肿瘤微环境。值得注意的是，USP43与表观遗传调控相关的mRNA干细胞样指数（epigenetically regulated-mRNAsi）存在关联，但与整体mRNA干细胞样指数（mRNAsi）无明显相关性。本研究证实了USP43在促进卵巢癌迁移与侵袭中的关键作用，并提出USP43可作为卵巢癌治疗的新型潜在靶点。

卵巢癌是所有妇科肿瘤中致死率最高的恶性肿瘤，但其发生发展的分子机制尚未完全阐明，因此本研究旨在深入解析卵巢癌的相关致病机制。本研究通过生物信息学方法对卵巢癌组织与正常组织进行差异基因分析，并结合WGCNA、Cox回归分析等手段，筛选得到与卵巢癌发生发展及预后相关的USP43基因。USP43是此前尚未在卵巢癌研究中被关注的基因，通过RNA干扰技术实验，本研究证实USP43可增强卵巢癌细胞的迁移与侵袭能力，并促进卵巢癌细胞发生上皮间质转化。此外，本研究还证实USP43与肿瘤免疫及肿瘤干细胞干性密切相关。上述研究结果表明，USP43可促进卵巢癌的发生发展，有望成为卵巢癌治疗的新型药物靶点。