Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, Heilongjiang, People's Republic of China.
Oral Oncol. 2013 Aug;49(8):796-801. doi: 10.1016/j.oraloncology.2013.03.454. Epub 2013 May 9.
Ubiquitin-specific protease 22 (USP22) could exhibit a critical function in pathological processes, including oncogenesis and cell cycle progression. This study examines the protein expression of USP22 in salivary duct carcinoma (SDC) in association with patient survival and other clinicopathologic parameters.
Quantitative RT-PCR and immunohistochemistry (IHC) were used to determine the expression of USP22 protein in 44 SDCs in comparison with 20 non-cancerous salivary tissues. Furthermore, we analyzed the correlation between the expression of the USP22 protein and various clinicopathologic factors including survival status of patients with SDC.
The incidence of positive USP22 expression was 63.7% in 44 SDC tissues. The mRNA level of USP22 expression in SDC samples was significantly higher than that in non-cancerous salivary tissues (P < 0.001), which was consistent with the IHC result (P < 0.001). Moreover, statistical analysis showed that positive USP22 expression was positively related to pT classification, pN classification and AJCC stage. Notably, high USP22 expression was significantly associated with shorter overall survival (P = 0.023) and disease-specific survival (P = 0.019). Multivariate Cox regression analysis revealed that USP22 expression level was an independent prognostic factor for both overall survival (P < 0.001) and disease-free survival (P < 0.001).
Our results indicate that activation of USP22 correlates with SDC progression and therapy failure. Overexpression of USP22 may contribute to the progression of SDC and thus may serve as a new molecular marker to predict the prognosis of SDC patients.
泛素特异性蛋白酶 22（USP22）在包括肿瘤发生和细胞周期进展在内的病理过程中可能具有关键功能。本研究检测了 USP22 蛋白在唾液腺癌（SDC）中的表达情况，并与患者生存和其他临床病理参数相关联。
采用定量 RT-PCR 和免疫组织化学（IHC）检测 44 例 SDC 与 20 例非癌唾液组织中 USP22 蛋白的表达。此外，我们分析了 USP22 蛋白表达与患者 SDC 生存状态等各种临床病理因素之间的相关性。
44 例 SDC 组织中 USP22 阳性表达率为 63.7%。SDC 样本中 USP22 表达的 mRNA 水平明显高于非癌唾液组织（P<0.001），与 IHC 结果一致（P<0.001）。此外，统计分析显示，USP22 阳性表达与 pT 分级、pN 分级和 AJCC 分期呈正相关。值得注意的是，USP22 高表达与总生存期（P=0.023）和疾病特异性生存期（P=0.019）显著相关。多变量 Cox 回归分析显示，USP22 表达水平是总生存期（P<0.001）和无病生存期（P<0.001）的独立预后因素。
我们的研究结果表明，USP22 的激活与 SDC 的进展和治疗失败有关。USP22 的过表达可能有助于 SDC 的进展，因此可能成为预测 SDC 患者预后的新分子标志物。
