Background: The prognosis of Epithelial Ovarian Cancer (EOC) is poor, but the prognostic biomarkers are neither sensitive nor specific. Therefore, it is very important to search novel prognostic biomarkers for EOC.

Objectives: The present study aimed to investigate Myosin Light Chain 9(MYL9) expression in Epithelial Ovarian Cancer (EOC) tissues (including paraffin-embedded and fresh tissue samples) and its relationship with clinicopathological characteristics, as well as its potential prognostic value in patients with EOC.

Methods: Between March 2009 and December 2018, all of 184 paraffin-embedded cancer tissues from patients with EOC and 41 paratumor tissues, pathologically confirmed at the Memorial Hospital of Sun Yat-sen University and Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, were collected for the present study and were assessed for MYL9 protein expression patterns using Immunohistochemistry (IHC). Furthermore, from August 2013 to November 2019, 16 fresh EOC tissues and their paired paratumor tissues, pathologically confirmed at the Integrated Hospital of Traditional Chinese Medicine, Southern Medical University were analyzed using Reverse-Transcription Quantitative PCR (RT-qPCR) to detect MYL9 mRNA expression levels.

Results: The results showed that MYL9 expression was higher in cancer tissues compared with that in paratumor tissues, and MYL9 overexpression was associated with shorter Recurrence Free Survival (RFS) and Overall Survival (OS) of EOC patients. Furthermore, multivariate Cox model analysis indicated that MYL9 overexpression was an independent poor survival prediction in patients with EOC.

Conclusion: MYL9 is upregulated in EOC and may serve as a useful patent of prognostic biomarker in EOC, and it may demonstrate an important value for the clinical treatment and supervision of patients with EOC.

背景：上皮性卵巢癌（EOC）的预后较差，但预后生物标志物既不敏感也不特异。因此，寻找新的 EOC 预后生物标志物非常重要。

目的：本研究旨在探讨肌球蛋白轻链 9（MYL9）在上皮性卵巢癌（EOC）组织（包括石蜡包埋和新鲜组织样本）中的表达及其与临床病理特征的关系，以及其在患者中的潜在预后价值。与平机会。

方法：2009 年 3 月至 2018 年 12 月，在中山大学纪念医院和南方医科大学中医院进行病理证实的 EOC 患者的 184 例石蜡包埋癌组织和 41 例癌旁组织，收集用于本研究，并使用免疫组织化学 (IHC) 评估 MYL9 蛋白表达模式。此外，从 2013 年 8 月至 2019 年 11 月，使用逆转录定量 PCR (RT-qPCR) 对 16 个在南方医科大学中医院病理证实的新鲜 EOC 组织及其配对的瘤旁组织进行分析，以检测 MYL9 mRNA表达水平。

结果：结果显示，MYL9在癌组织中的表达高于癌旁组织，MYL9过表达与EOC患者的无复发生存期（RFS）和总生存期（OS）较短有关。此外，多变量 Cox 模型分析表明 MYL9 过表达是 EOC 患者的独立不良生存预测。

结论：MYL9在EOC中表达上调，可作为EOC预后生物标志物的一项有用专利，对EOC患者的临床治疗和监测具有重要价值。