TY - JOUR
T1 - Presence of human papillomavirus sequences in tumour-derived human oral keratinocytes expressing mutant p53
AU - Yeudall, W. A.
AU - Paterson, I. C.
AU - Patel, V.
AU - Prime, S. S.
N1 - Funding Information:
Acknowledgements-We are grateful to Dr L. Crawford for providing us with initial aliquots of PAbl801 antibody and the pProSp53 cDNA clone and Dr A. Williams for HT29 cells. We thank Drs K. Parkinson and A. Williams for helpful discussion and comments, and MS K. Elsegood and Mr A. Fathers for technical assistance. We thank Mr G. Irvine and Dr A.W. Barrett for access to patient details, and Professor C. Scully for continuing support and encouragement. This work was supported by a United Bristol Hospitals Trust grant to WAY and SSP, and a Unilever Award to WAY. ICI’ is funded by the MRC.
PY - 1995/3
Y1 - 1995/3
N2 - A series of eight oral epithelial cell lines derived from untreated human oral squamous cell carcinomas, which had arisen in patients with different tobacco histories, were examined for the presence of human papillomavirus (HPV) DNA, expression of stable p53 protein and p53 point mutation. Polymerase chain reaction (PCR)-based screening, but not Southern blot analysis, showed HPV-16 early region sequences to be present at low copy number (< 1 copy per cell) in two cell lines at early passage (3-5) in vitro (H400, T45), implying that only subpopulations of cells harboured viral DNA. HPV sequences were undetectable in cells at later passage (12-15), suggesting that viral sequences had been lost during growth in vitro, or that negative selection of HPV-containing cells had occurred. High levels of p53 were detected in the two HPV-positive cell lines and in three others (H103, H314, H357) by Western blotting, suggesting expression of mutant (stable) p53 molecules. A sixth cell line (H157) expressed a truncated p53. Sequence analysis of exons 2-11 of the p53 gene revealed missense mutations in six cell lines, one of which (H413) did not result in high levels of protein, and nonsense mutations in the remaining two cell lines (H157, H376). The results suggest that p53 mutation is a frequent genetic event in oral cancer. In addition, the expression of mutant p53 in oral cancer cells does not preclude a papillomaviral aetiology for these tumours. Analysis of p53 expression alone may result in underestimation of the frequency of p53 mutations in human cancers. In contrast to other studies, we demonstrate that positive staining of p53 in oral cancer does not necessarily reflect a tobacco aetiology.
AB - A series of eight oral epithelial cell lines derived from untreated human oral squamous cell carcinomas, which had arisen in patients with different tobacco histories, were examined for the presence of human papillomavirus (HPV) DNA, expression of stable p53 protein and p53 point mutation. Polymerase chain reaction (PCR)-based screening, but not Southern blot analysis, showed HPV-16 early region sequences to be present at low copy number (< 1 copy per cell) in two cell lines at early passage (3-5) in vitro (H400, T45), implying that only subpopulations of cells harboured viral DNA. HPV sequences were undetectable in cells at later passage (12-15), suggesting that viral sequences had been lost during growth in vitro, or that negative selection of HPV-containing cells had occurred. High levels of p53 were detected in the two HPV-positive cell lines and in three others (H103, H314, H357) by Western blotting, suggesting expression of mutant (stable) p53 molecules. A sixth cell line (H157) expressed a truncated p53. Sequence analysis of exons 2-11 of the p53 gene revealed missense mutations in six cell lines, one of which (H413) did not result in high levels of protein, and nonsense mutations in the remaining two cell lines (H157, H376). The results suggest that p53 mutation is a frequent genetic event in oral cancer. In addition, the expression of mutant p53 in oral cancer cells does not preclude a papillomaviral aetiology for these tumours. Analysis of p53 expression alone may result in underestimation of the frequency of p53 mutations in human cancers. In contrast to other studies, we demonstrate that positive staining of p53 in oral cancer does not necessarily reflect a tobacco aetiology.
KW - chemical carcinogens
KW - gene mutation
KW - human papillomavirus
KW - oral cancer
KW - p53
KW - tumour progression
KW - tumour suppressor
KW - viral oncogenesis
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U2 - 10.1016/0964-1955(94)00030-8
DO - 10.1016/0964-1955(94)00030-8
M3 - Article
C2 - 7633286
AN - SCOPUS:0029079133
SN - 0964-1955
VL - 31
SP - 136
EP - 143
JO - European Journal of Cancer. Part B: Oral Oncology
JF - European Journal of Cancer. Part B: Oral Oncology
IS - 2
ER -