Human papillomavirus DNA and abnormal p53 Tumor Suppressor Gene in Lung Carcinoma

A powerful relationship has been established between high-risk human papillomaviruses (HPV) and TP53 mutations with lung cancer. We evaluate the frequency of HPV types and TP53 mutations in squamous cell carcinoma (SCC) of lung, among patients from Tabriz. 50 Paraffin embedded blocks of lung SCC were selected for detection of HPV DNA by Nested PCR with the MY09/11 and GP5+/6+ primer sets, Then DNA sequenced for HPV typing. Equal numbers of positive and negative samples for the HPV DNA were examined for the presence of mutations in exons5-7 of the TP53 gene by PCR and direct sequencing. 9 (18%) out of 50 samples presented the HPV DNA; eight were HPV-18 and one was HPV-6. TP53 mutations were found in 5 samples (27.7%). One of HPV negative and three of the HPV positive cases had a mutation in exon5 and one HPV positive case had a mutation in exon7. Frequent mutations were C to G transversion (c.409C>G) in exon5 and T to A tansversion (c.770T>A) in exon7. Our study showed that HPV-18 is likely to result in development of lung cancer in some communities. Genetic alterations, alongside environmental factors, play a significant role in the pathogenesis of lung SCC.

Keywords:

Human papillomavirus , TP53 mutations , squamous cell carcinoma