Supplementary Material for: AQP5 Variants Affect Tumoral Expression of AQP5 and Survival in Patients with Early Breast Cancer

<b><i>Background:</i></b> Our previous study showed the association of AQP5 upregulation with cancer proliferation and migration in breast cancer cell lines and with unfavorable prognosis in patients with early breast cancer (EBC). In the current study, we analyzed the association of<i> AQP5</i> variants or their haplotypes with AQP5 expression and their prognostic impact for survival in patients with EBC. <b><i>Methods:</i></b> Three <i>AQP5</i> polymorphisms (rs74091166, rs3736309, and rs1964676) were selected based on the SNP database and genotyped using the Sequenom MassARRAY in 374 out of 447 patients with EBC in whom AQP5 expression had been investigated in our previous study. <b><i>Results:</i></b> The allele frequencies of the selected variants in the current study were similar to those from Asian data previously reported. In a univariate analysis, both rs74091166 and rs1964676 were statistically associated with survival as a dominant model of minor allele. Moreover, a multivariate survival analysis revealed that the CC genotype of rs1964676 is an independent prognostic marker of survival in EBC patients, regardless of stage, tumor subtype, and adjuvant treatment [hazard ratio = 0.399, 0.384, and 0.205; <i>p</i> = 0.021, 0.027, and 0.016 for disease-free survival (DFS), distant DFS, and disease-specific survival, respectively]. In particular, the CT/TT genotype of rs1964676 showed an association with strong expression of AQP5 (58.6 vs. 26.0%; <i>p</i> = 0.001), without any associations with clinical or pathological characteristics including tumor subtype, stage, or histologic grade. <b><i>Conclusion:</i></b> The current study suggests <i>AQP5 </i>rs1964676 as a new potential prognostic marker in patients with EBC involved in AQP5 expression.

<b><i>背景：</i></b> 我们既往的研究表明，水通道蛋白5（AQP5）的上调与乳腺癌细胞系中的癌细胞增殖、迁移相关，同时与早期乳腺癌（EBC）患者的不良预后相关。本研究旨在分析AQP5变异体或其单倍型与AQP5表达的关联，以及其对EBC患者生存的预后影响。<b><i>方法：</i></b> 我们基于单核苷酸多态性（SNP）数据库筛选出3个AQP5多态性位点（rs74091166、rs3736309及rs1964676），并采用Sequenom MassARRAY平台对既往研究中已检测AQP5表达的447例EBC患者中的374例进行了基因分型。<b><i>结果：</i></b> 本研究中所选变异位点的等位基因频率与既往报道的亚洲人群数据相近。单因素分析结果显示，以次要等位基因的显性模型分析时，rs74091166与rs1964676均与患者生存存在统计学关联。进一步的多因素生存分析表明，rs1964676的CC基因型可作为EBC患者生存的独立预后标志物，且不受临床分期、肿瘤亚型及辅助治疗的影响[风险比（hazard ratio）分别为0.399、0.384及0.205；无病生存期（DFS）、远处无病生存期及疾病特异性生存期对应的<i>p</i>值分别为0.021、0.027及0.016]。尤为关键的是，rs1964676的CT/TT基因型与AQP5高表达显著相关（58.6% vs. 26.0%；<i>p</i>=0.001），且与肿瘤亚型、临床分期及组织学分级等临床病理特征均无显著关联。<b><i>结论：</i></b> 本研究表明，AQP5 rs1964676可作为与AQP5表达相关的早期乳腺癌患者潜在的新型预后标志物。