association of beta-catenin gene mutations and human papillomavirus in carcinoma of esophagus in a high-risk population of India

ABSTRACT

Esophageai cancer [EC] is the sixth leading cause of death from cancer. In high-risk regions, squamous cell carcinoma is the most common type of EC, and its etiology remains poorly understood. It shows uneven geographical distribution in its occurrence, reflecting the influence of local environmental conditions, lifestyle and genetic predisposition in the development of the cancer. Kashmir, in the north of India, has been described as a high-risk area for esophageal squamous cell carcinoma [ESCC]. In the present investigation an attempt was made to study the role of p-catenin mutations and human papillomavirus in 62 ESCC patients from Kashmir. The hot spot mutation region of p-catenin exon 3 was evaluated in matched tumor and normal tissues using a combination of PCR-SSCP and direct sequencing. We used two different sets of consensus primers viz., GP5+ and GP6+; PGMY09 and PGMY11 in conjunction with reverse line blot assay to screen for human papillomavirus [HPV]. None of the tumors showed the presence of commonly reported mutations in p-catenin. In view of the fact that HPV has been linked to pathogenesis of EC, we screened all the tumor and control specimens for the presence of HPV and we didn't detect HPV in any of the matched tumor and control specimens in contrast to the positive controls we used. In conclusion our results suggest that squamous cell carcinoma of esophagus in Kashmir may arise independent of oncogenic p-catenin mutations and HPV is unlikely to be an etiologic factor for ESCC in this region