Oral cancer is reported to be one of the most frequent cancers among men and women around the world, and most of the cases are present in male [19–21]. From the results of epidemiologic study, a wide of environmental carcinogens have been found correlate with the tumorigenesis of oral cancer, and the most prevalent members including abuse of alcohol, betel quid and tobacco [22, 23]. The overall survival of patients with early stage oral cancer is better than the other malignancies, but it is rather poor in the patients at advanced lesion . Thus, it is necessary to develop new prognostic tools and effective therapeutics that may be beneficial for improving the clinical management of oral cancer. In the recently studies, application of prognostic biomarkers has directed the research in the tumor studies [25, 26]. For example, Xu et al. have found that fibulin-5 could serve as an independent prognostic factor and promote the proliferation and invasion in glioma . Similarily, there are some biomarkers have been found to be associated with prognosis of oral cancer. Kumar et al. have demonstrated that nuclear heterogeneous nuclear ribonucleoprotein D was correlated with cellular proliferation and overall survival, and acted as a potential prognostic factor for oral cancer patients . It is helpful to improve the prognosis and treatment of oral cancer by finding more efficient prognostic biomarkers.
KRT family represents a series of intermediate filament proteins in abundant epithelial cells . In cancer, keratins have traditionally been used as diagnostic tools, but accumulating evidence points to their importance as prognostic markers and active regulators of epithelial tumorigenesis . KRT17, a member of KRT family, has been originally described as a major KRT in the basal cell skin cancers . The studies in the last decade have demonstrated that KRT17 could be used to distinguish the cancer cases from healthy controls for diverse human carcinomas, such as lung cancer, prostate carcinoma and pancreaticobiliary adenocarcinomas [31–33]. All these data suggest its potential functional role in human cancers. In oral cancer, KRT17 has also been investigated and proved to facilitate the growth of oral cancer cells and promote the tumorigenesis .
In the present study, we found the deregulated expression of KRT17 in oral cancer tissues compared with the paired normal tissues by using qRT-PCR method. Then we wonder if KRT17 was involved in the progression of oral cancer. Thus, the relationship between KRT17 expression and oral cancer patients’ clinicopathological characteristics was assessed with Chi-square test. By this analysis, the remarkable relationship between KRT17 expression and lymph node metastasis and clinical stage was found. These results indicated that expression of KRT17 was involved in the development of oral cancer.
As the KRT17 expression was found dysregulated and correlated with progression of oral cancer, we further assessed its clinical significance in prognosis of this malignant disease. In the current study, we first examined the relationship between KRT17 expression with overall survival of oral cancer patients, and found that the high levels of KRT17 was associated with poor overall survival in the oral cancer patients. Then, we adopted the multivariate Cox regression to perform the influences of KRT17 on the overall survival of oral cancer patients. From the results of Cox analysis, we considered that the increased expression of KRT17 was an independent prognostic biomarker in patients with oral cancer.