Expression of mutant p 53 in oral squamous cell carcinoma is correlated with the effectiveness of intra-arterial chemotherapy

The aim of the present study was to evaluate the correlation between the positive expression rate of mutant p53 and the clinical characteristics of patients with oral squamous cell carcinoma (OSCC), as well as the effectiveness of intra-arterial chemotherapy. Expression of mutant p53 in tumor tissues was determined by immunohistochemical analysis of 51 OSCC patients, prior to and following intra-arterial chemotherapy. Prior to intra-arterial chemotherapy, mutant p53 positive rates in patients with higher pathological grades were significantly higher than those of the patients with lower pathological grades. The mutant p53 positive rate in patients with lymph node metastasis was 73% (19/26), which was significantly higher than that of the patients without lymph node metastasis (20%, 5/25). Mutant p53 was expressed in 17% (3/18) of clinical phase II patients, while 64% (21/33) of clinical phase III and IV patients exhibited positive expression of mutant p53 (P<0.05). The mutant p53 positive rate in chemotherapy non-responsive patients was 69% (11/16), which was significantly higher than that in the chemotherapy-responsive patients (37%, 13/35). Mutant p53 positive rates were not significantly correlated with age, gender or the location of the tumor. The mutant p53 positive rate prior to chemotherapy was 47% (24/51), and decreased to 18% (9/51) following chemotherapy. Expression of mutant p53 was decreased in all 13 (100%) chemotherapy-responsive patients, while only 5 (45%) chemotherapy non-responsive patients exhibited reduced expression levels of mutant p53 (P<0.05). In conclusion, mutant p53 has a significant role in the differentiation, development and treatment guidance of OSCC. Intra‐arterial chemotherapy with 5‐fluorourcil and carboplatin potentially exerts a therapeutic effect by reducing the expression of mutant p53. Introduction Oral squamous cell carcinoma (OSCC) is the most common tumor of the head and neck in India (1) and is the most prevalent oral malignancy worldwide, with ~274,300 cases diagnosed annually (2). Increasing attention has been paid to OSCC due to its high risk of malignancy and invasion, rapid metastasis and increasing occurrence. Although a variety of novel approaches have been proposed for the treatment of OSCC, surgery remains the most effective strategy (3), while radiotherapy and chemotherapy are recommended for malignancies. Chemotherapy has been widely applied as a significant component of comprehensive treatment for OSCC. Surgery complemented with neoadjuvant chemotherapy is the most common comprehensive treatment program for OSCC. Neoadjuvant chemotherapy may achieve short-term clinical remission of tumors and reduce the size of the primary tumor (4), thereby enhancing tumor resection rate, increasing the negative rate of the resection edge, inhibiting tumor metastasis (5), reducing postoperative tissue defects and improving the quality of life of patients, particularly those requiring oral and maxillofacial surgery. Regional arterial infusion may achieve a high concentration of anticancer drugs surrounding the tumor, and maximize the apoptotic effect on tumor cells without apparent toxicity. Therefore, this treatment strategy provides a precise, simple, long-term, low-toxicity and highly effective method of drug administration (6). Eckardt et al (7), achieved marked clinical remission for patients with advanced head and neck squamous cell carcinoma by utilizing regional arterial infusion chemotherapy. A combination of 5-fluorourcil (5‐Fu) and carboplatin has been demonstrated to be an effective treatment regimen for OSCC (8,9). Regional arterial infusion chemotherapy with 5‐Fu and carboplatin for the treatment of OSCC has previously been utilized by our group, and achieved marked clinical efficacy (10,11). Various studies have demonstrated that mutation of the p53 gene has a significant role in tumor development (12‐17). When DNA is damaged by physical and/or chemical factors, p53 gene transcription is increased and wild-type p53 protein is concentrated, which results in arrest of the cell cycle at G1/S phase and apoptosis of cells with cancerous characteristics (18). When the p53 gene is mutated, mutant p53 protein loses its cancer inhibition function and promotes the transExpression of mutant p53 in oral squamous cell carcinoma is correlated with the effectiveness of intra-arterial chemotherapy YADONG LI and JINSONG ZHANG Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China Received October 13, 2014; Accepted July 21, 2015 DOI: 10.3892/ol.2015. 3651 Correspondence to: Mr. Jinsong Zhang, Department of Oral and Maxillofacial Surgery, The First Affliated Hospital of Chongqing Medical University, 1 Youyi Road, Chongqing 400016,