New PIK3CA gene mutation in cervical cancer patients

Abstract

Objectives: This study aimed to detect PIK3CA gene mutations in Pap smears from cervical cancer patients using SYBR green real time-PCR (SYBR green RT-PCR) and to estimate the frequency of PIK3CA gene mutations in cervical cancer patients from Kalasin Hospital, Kalasin Province, Thailand. Method: The DNA from Pap smears of 73 cervical cancer patients was extracted. Mutations of the PIK3CA gene on exons 9 and 20 were detected using SYBR green PCR. Then the melting curve was analyzed. The mutations in the samples were confirmed by DNA sequencing. Result: There were three (16.6%) cases that had a mutation of the PIK3CA gene on exon 9. Two of them were found to have the mutation at S555T (serine to threonine; c. 1668 G>C and c.1669T del). Another one was found with the mutation at S555T (c. 1668 G>C and c.1669T del) plus E545A (glutamic acid to alanine; c.1634A>C). All of them had Tm values lower than the Tm values of the negative control. There were no mutations on exon 20. Conclusion: Pap smear samples could be used for screening of the mutation of PIK3CA on exons 9 and 20 using SYBR green PCR before DNA sequencing. This could save costs and could be performed in general hospitals.