The Oncogenetic Role Of Calcium-binding Protein S100A4 In Ocular Melanoma And Clinical Analyses Of Chinese Patients With Ocular Malignancy

Objectives: Ocular malignancy is an important disease that can lead to blindness,morbidity,and even mortality.Ocular melanoma primarily derives from conjunctiva and uvea.Eyelid sebaceous carcinoma usually arises from Meibomian gland or Zeis gland.And the prevalence of this disease is significantly higher than that of western countries.First,we investigated the role of S100A4 in the pathogenesis of uveal melanoma(UM)and explored a plausible targeted therapy with its inhibitor calcimycin.Furthermore,we analyzed the clinical characteristics of Chinese patients based on 2retrospective cohorts,thus providing theoretical foundation and a new strategy for the management of ocular malignancy.Methods:1.Transcriptional and label-free proteomic analyses were utilized to determine the possible oncogenes in UM.Then,the levels of S100A4 was validated in cells and tissues.The role of S100A4 in UM and its underlying mechanisms were investigated.We inhibited S100A4 either by sh RNAs or calcimycin to explore its impact on the proliferation and cell motility,in vitro as well as in vivo.Transcriptome sequencing combined with co-immunoprecipitation(Co-IP)mass spectrometry were utilized to unveil the mechanism for S100A4-promoted tumorigenesis in UM.2.A retrospective cohort study of 57 patients with conjunctival melanoma from Shanghai Ninth People's Hospital between 1996 and 2016.All eligible patients were followed up for recurrence,metastasis and tumor-related mortality.The prognostic factors were determined by Cox regression.The clinical characteristics and outcomes were compared between Chinese and Caucasian patients.3.A multicenter cohort study of 360 patients with eyelid sebaceous carcinoma from Shanghai Ninth People's Hospital,the Second Affiliated Hospital of Zhejiang University School of Medicine and Xiangya Hospital between 1991 and 2017.All eligible patients were followed up for recurrence,metastasis and tumor-related mortality.The impact of Mohs micrographic surgery(MMS)and wide local excision(WLE)on the prognoses were determined by Cox analyses.A subgroup analyses was performed in patients with pagetoid intraepithelial invasion.Results:1.S100A4 was upregulated in UM cell lines and tissues.We inhibited S100A4 either by sh RNAs or calcimycin,the proliferation and cell motility were markedly suppressed in vitro as well as in vivo.The underlying mechanism lies in that S100A4 recruits MDM2 complex with p53 and enhances direct binding of ubiquitin to p53,facilitating its degradation,finally,promoting the tumorigenesis of UM.2.The 5-year recurrence,metastasis and tumor-related mortality for conjunctival melanoma was 59.7%,38.7% and 30.5%,respectively.Tumor hemorrhage is the independent risk factors for metastasis(HR: 4.57,p=0.02)and tumor-related death(HR:18.81,p=0.01).Significant differences were noted between Chinese and Caucasians patients in clinical characteristics and outcomes(all p<0.05).3.Among 360 patients of eyelid sebaceous carcinoma included in this cohort,115(31.9%)of them underwent MMS as primary resection,whereas 245(68.1%)cases received WLE.Multivariable Cox regression indicated that,compared with the WLE group,the MMS group exhibited more favorable local recurrence control(HR=0.42;p<0.01),but a comparable metastasis rate(HR=1.38;p=0.45)and tumor-related mortality(HR=1.70;p=0.33).However,this beneficial effect became nonremarkable for patients with pagetoid intraepithelial neoplasia(HR=1.73;p=0.49).Conclusions:1.The discovery of this study carries important translation implications that S100A4 plays an important oncogenic role in ocular melanoma,and targeting it provides a plausible therapeutic strategy for the treatment of ocular melanoma.2.Conjunctival melanoma is a rare malignancy with great potential for mortality in Chinese.Special attention should be paid to patients with tumor hemorrhage.Compared to the Caucasians,Chinese patients exhibit more aggressive clinical signs with compromised prognosis.3.MMS should be proposed for eyelid sebaceous carcinoma without orbital involvement to achieve recurrence control,however,this surgery did not change the long-term outcomes in terms of metastasis and tumor-related mortality.