卵巢癌作为第三大常见的妇科恶性肿瘤，约有80%以上的卵巢癌患者处于晚期，5年生存率只有30% ~ 40%。且卵巢癌在初发时往往伴有广泛的腹腔内转移灶，因此以铂类药物为基础的化疗一直是卵巢癌的主要治疗方式之一。然而铂类化疗对卵巢癌的有效时间较短，70%的患者会在2年内复发并最终转为铂耐药，预后极差。目前，铂耐药仍是卵巢癌临床治疗面临的重要挑战，亟待探寻预测新辅助治疗疗效的潜在标志物及靶向铂耐药的治疗策略实现个体化的精准诊疗。卵巢癌铂耐药主要由药物积累与外排、DNA损伤修复、死亡通路、细胞代谢、表观遗传、肿瘤微环境及细胞外基质等的异常改变引起，是一个多基因多种基质参与的复杂过程。其中细胞周期蛋白依赖性激酶 (CDK) 异常激活及铜死亡通路的异常与肿瘤的化疗耐药密切相关。本研究中我们基于卵巢癌多组学数据解析，揭示CDK5与Wiskott-Aldrich 综合症蛋白质家族成员2（WASF2）参与介导卵巢的铂耐药。

基于卵巢癌基因组数据，通过cBioPortal分析，我们发现CDK5在卵巢癌中显著扩增，然而CDK5调控卵巢癌细胞转移及耐药的机制尚不明确。我们利用卵巢癌组织芯片及免疫组织化学分析发现CDK5高表达与卵巢癌转移、铂耐药及不良预后密切相关；基因集富集分析（GSEA）发现，在CDK5^High组，DNA复制和细胞周期相关基因显著富集，而在CDK5^Low组，粘附和胞外基质相关基因显著富集，提示CDK5可能参与调控细胞增殖及转移。上述研究结果提示CDK5可以作为靶向卵巢癌铂耐药的潜在治疗靶点。为了探究靶向CDK5的治疗策略，我们筛选并鉴定CDK5抑制剂20-223，借助卵巢癌原代细胞和小鼠腹腔注射模型评价20-223抑制卵巢癌细胞转移及改善铂耐药的疗效，为临床改善卵巢癌铂耐药提供了一种新的治疗策略。系统地阐述了CDK5通过调控RAC3表达，促进侵入性伪足的形成，介导卵巢癌转移的分子机制。

基于卵巢癌的单细胞测序数据，转录组数据和临床数据，我们一共确定了六种主要细胞群，包括成纤维细胞、T细胞、髓细胞、上皮细胞、内皮细胞和B细胞群。通过PROGENy 评分，我们发现T和B细胞的PI3K通路显著激活，内皮细胞和成纤维细胞的TGF-β通路激活。根据铜死亡相关基因表达高/低分组，将单个细胞分为铜死亡偏高组（cuproptosis^high）和铜死亡偏低组（cuproptosis^low），筛选了两组间的差异表达基因，确定了47个预后相关基因，同时构建了基于7个基因：TIMM8B、COX8A、SSR4、HIGD2A、WASF2、PRDX5和CLDN4 的预后模型用于预测卵巢癌预后及免疫特征。通过实验初步证实WASF2与铜死亡相关，可以促进癌细胞增殖和铂耐药。

综上所述，基于卵巢癌多组学的数据解析，确定CDK5可以作为卵巢癌潜在的治疗靶点及疗效预测的标志物，同时构建了基于7个基因的预后模型用于预测卵巢癌预后与免疫特征，并验证了其中WASF2促进卵巢癌细胞增殖和铂类抗性的功能；系统阐述了CDK5-RAC3-cofilin轴调控卵巢癌转移的分子机制，靶向CDK5有望为临床改善卵巢癌铂耐药提供了一种新的治疗策略。

Ovarian cancer is the deadliest form of gynecologic cancer and ranks as the third most common gynecologic malignancy worldwide with a 5-year overall survival rate of about 30% ~ 40%. About 80% of ovarian cancer patients are in advanced stage. Ovarian cancer is often accompanied by extensive intraperitoneal metastases at the initial onset. Platinum-based chemotherapy has been the backbone of systemic treatment in ovarian cancer, and the initial response is pretty high. However, 70% of patients eventually relapse and turn to platinum resistance, leading to poor survival. At present, platinum resistance is still a challenge in the clinical treatment of ovarian cancer, and it is urgent to explore potential markers to predict the efficacy of neoadjuvant therapy and therapeutic strategies targeting platinum resistance to achieve individualized precision diagnosis and treatment. Platinum resistance of ovarian cancer, as a complex process involving multiple genes and multiple matrices, is mainly caused by abnormal changes in drug accumulation and efflux, DNA damage repair, cell death, cell metabolism, epigenetics, tumor microenvironment and extracellular matrix. Abnormal activation of cyclin- dependent kinase (CDK) and abnormal cuproptosis are closely related to chemoresistance. In this study, based on multi-omics data analysis of ovarian cancer, we revealed that CDK5 and Wiskott-Aldrich syndrome protein family member 2 (WASF2) are involved in mediating ovarian platinum resistance.

 Based on the genomic data in ovarian cancer, we found that cyclin-dependent kinase-5 (CDK5) represents the most significant oncogene amplified in ovarian cancer through the cBioPortal for Cancer Genomics. We further consolidated the clinical relevance of CDK5 expression via immunohistochemistry (IHC) in ovarian cancer tissue microarrays. We demonstrated that CDK5 prompts worse clinical characteristics and platinum resistance in ovarian cancer. Intriguingly, gene ontology (GO) analysis of the differentially expressed genes (DEGs) in the TCGA database showed genes related to “DNA replication” and “cell cycle” were significantly enriched in ovarian cancer patients with higher CDK5 expression, while genes related to “focal adhesion” and “extracellular matrix organization” were significantly enriched in ovarian cancer patients with lower CDK5 expression. These results signified CDK5 as a potential biomarker and promising target for ovarian cancer therapy. Moreover, the usage of CDK5 inhibitor 20-223 can effectively suppress cancer proliferation and metastasis in cancer cells, and synergize the killing effect of platinum-based chemotherapy with the application of patient-derived cells (PDCs), and mouse models by intraperitoneal injection, providing a better strategy for boosting the efficacy of platinum-based chemotherapeutics in ovarian cancer. Through RNA-sequencing analysis, we found that CDK5 can influence the remodeling of the actin cytoskeleton and the formation of invadopodia through RAC3, leading to altered cell motility.

Based on integrated single-cell sequencing data, transcriptome data, and clinical data from multiple databases of ovarian cancer, we assessed the activation of tumor-associated pathways in six cell groups: fibroblast, T cell, myeloid, epithelial cell, endothelial cell, and B cell populations. The PROGENy score revealed the significant activation of the PI3K pathway in T and B cells, and activation of the TGF-β pathway in endothelial cells and fibroblasts. Based on gene set enrichment analysis (GSEA) of the cuproptosis pathway, the single cells were divided into the cuproptosishigh and cuproptosislow groups. The differentially expressed genes (DEGs) between the two groups were screened, and 47 prognosis-related genes were identified. TIMM8B, COX8A, SSR4, HIGD2A, WASF2, PRDX5 and CLDN4 were selected to construct a prognostic model from the identified 47 prognosis-related genes, which can accurately predict the prognosis and immune characteristics of ovarian cancer patients. The functional experiments showed that WASF2 is associated with cuproptotic resistance and promotes cancer cell proliferation and resistance to platinum.

Collectively, based on the analysis of multi-omics data of ovarian cancer, these results show that CDK5 is a potential biomarker and promising target for ovarian cancer therapy. Moreover, the establishment of a clinically significant cuproptosis-related prognostic model based on 7 genes can accurately predict the prognosis and immune characteristics of ovarian cancer patients, and we found that WASF2, as one of the cuproptosis-related gene in the prognostic model, promotes the proliferation and platinum resistance, and leads poor prognosis. Moreover, we systematically elaborated the molecular mechanism of CDK5-RAC3-Cofilin axis in ovarian cancer metastasis, and selected an effective CDK5 inhibitor 20-223, which provided a new therapeutic strategy for improving platinum resistance of ovarian cancer.