Analysis of TP53 gene mutation and its intratumoral heterogeneity in esophageal squamous cell carcinoma

Objective To explore the correlation between TP53 gene mutation heterogeneity state of esophageal squamous cell carcinoma(ESCC) tumor and clinicopathologic features. Methods The primary tumor of Esophageal Squamous Cell Carcinoma(ESCC) and its operational end cutting issues were prepared.PCR and direct sequencing were performed to detect TP53 gene exon No. 2-11 mutation status and assesse the correlation of TP53 gene mutation and clinicopathological parameter of 4 different locations of tumor lesions and its intratumoral heterogeneity. Results Among 30 cases of Esophageal Squamous Cell Carcinoma(ESCC) tumors,18 cases were with TP53 mutations with a proportion of 60%(18/30),which including 16 cases of point mutations,3 cases of nonsense mutations,13 cases of missense mutations,and 2 cases of deletion mutation that lead to frame shift.Most mutations were focused on the TP53 gene No. 5-8 exons,while No. 5 was with the highest mutation rate of 23.3%(7/18).The 282th exons codon mutation(R282W) was found in 2 cases,175 exons codon mutations(R175H) in 3 cases.By comparing the ratio of mutant allele peak height and normal allele peak height(relative intensity,RI),we found that there was obvious differences in 4 tumor location RI in 12 of 16 cases,the remaining 4 cases were also with different location RI. Conclusion The high frequency of TP53 gene mutation in esophageal squamous cell carcinoma(ESCC) and each tumor is with different degree of intratumoral heterogeneity.