Lv Zhongjing, Wu Kun, Qin Xing, Yuan Jian, Yan Ming, Zhang Jianjun, Wang Lizhen, Ji Tong, Cao Wei, Chen Wantao
Department of Oral and Maxillofacial-Head and Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
Department of Stomatology, Affiliated Hospital of Xuzhou Medical University, Xuzhou City, Jiangsu Province, People's Republic of China.
Cancer Manag Res. 2020 Jun 23;12:4855-4869. doi: 10.2147/CMAR.S236266. eCollection 2020.
In our previous study, serine protease inhibitor Kazal-type 5 (SPINK5), which encodes the product of serine protease inhibitor lymphoepithelial Kazal-type-related inhibitor (LEKTI) was found to be down-regulated in head and neck squamous cell carcinoma (HNSCC) using oligonucleotide microarrays. However, the function and clinical implications of SPINK5/LEKTI remain obscure in HNSCC.
The endogenous expression level of SPINK5/LEKTI was further verified in 9 HNSCC cell lines and HNSCCs by means of reverse transcription-polymerase chain reaction, real-time PCR, Western blotting and immunohistochemistry. The biological function of SPINK5/LEKTI was investigated in vitro and in vivo experiments. Kaplan-Meier survival analysis and Cox proportional hazards regression model were used to determine the correlation between SPINK5/LEKTI expression and clinical outcome.
Down-regulation expression of SPINK5/LEKTI was found in six out of nine HNSCC cell lines and in 85.7% HNSCC specimens (<0.0001). Upon silencing of SPINK5/LEKTI, the cell proliferation, plate colony formation and cell invasion of WU-HN6 cells were significantly increased, while exogenous overexpression of SPINK5/LEKTI, the proliferation, plate colony and invasion of WU-HN13 and HN30 cells were remarkably inhibited with the arrest of G1 cell cycle (=0.0001, =0.003, respectively). HNSCC patients with lower LEKTI levels had significantly inferior overall survival compared to those patients with higher LEKTI (=0.0017) by Kaplan-Meier survival analysis. Univariate and multivariate Cox proportional hazards regression model analysis revealed that LEKTI expression was an independent prognostic predictor for HNSCC patients (HR=0.114, 95% CI:0.044-0.292, <0.001).
Our results demonstrate that SPINK5/LEKTI might be a tumor suppressor in HNSCCs and serve as an independent prognostic predictor for HNSCC patients.
在我们之前的研究中，使用寡核苷酸微阵列发现，编码丝氨酸蛋白酶抑制剂淋巴细胞上皮Kazal型相关抑制剂（LEKTI）的丝氨酸蛋白酶抑制剂Kazal型5（SPINK5）在头颈部鳞状细胞癌（HNSCC）中表达下调。然而，SPINK5/LEKTI在HNSCC中的功能和临床意义仍不清楚。
通过逆转录-聚合酶链反应、实时PCR、蛋白质免疫印迹和免疫组织化学进一步验证9种HNSCC细胞系和HNSCC中SPINK5/LEKTI的内源性表达水平。通过体外和体内实验研究SPINK5/LEKTI的生物学功能。采用Kaplan-Meier生存分析和Cox比例风险回归模型确定SPINK5/LEKTI表达与临床结果之间的相关性。
在9种HNSCC细胞系中的6种以及85.7%的HNSCC标本中发现SPINK5/LEKTI表达下调（<0.0001）。沉默SPINK5/LEKTI后，WU-HN6细胞的细胞增殖、平板集落形成和细胞侵袭显著增加，而外源性过表达SPINK5/LEKTI后，WU-HN13和HN30细胞的增殖、平板集落和侵袭受到显著抑制，G1细胞周期停滞（分别为=0.0001，=0.003）。通过Kaplan-Meier生存分析，与LEKTI水平较高的患者相比，LEKTI水平较低的HNSCC患者总生存期明显较差（=0.0017）。单因素和多因素Cox比例风险回归模型分析显示，LEKTI表达是HNSCC患者的独立预后预测指标（HR=0.114，95%CI：0.044-0.292，<0.001）。
我们的结果表明，SPINK5/LEKTI可能是HNSCC中的一种肿瘤抑制因子，可作为HNSCC患者的独立预后预测指标。
