SEQUENCE REARRANGEMENTS IN THE UPSTREAM REGULATORY REGION OF HUMAN PAPILLOMAVIRUS TYPE-6 - ARE THESE INVOLVED IN MALIGNANT TRANSITION

Human papillomavirus type 6 (HPV-6) was isolated from a tongue papillo ma which subsequently progressed to an invasive carcinoma. Three biops ies were taken from the same patient at different intervals during the tumour development. The HPV-6 genome in all three biopsies contained a GT-rich 94 bp insertion at nucleotide 7350 in the upstream regulator y region (URR). In comparison to previously published HPV-6 DNA isolat es, this insertion seems to be the most prevalent and constant modific ation, not present in the prototype HPV-6b, and allows an improved ali gnment with the sequence of the HPV-11 genome. The possible biological significance of these GT-rich clusterings at the beginning of the URR , present not only in these HPV-6 isolates but observed in all other ' genital' HPVs also, is discussed.