p53 mutations, protein expression and cell proliferation in squamous cell carcinomas of the head and neck

A non-random deletion in the p53 gene in oral squamous cell carcinoma

“…The obvious predominance of missense over non-missense mutations is, however, only seen between codons 130 and 286 (Greenblatt et al, 1994). In an earlier study of p53 mutations in SCCHN we found a deletion of 14 bp in exon 8 in one tumour (Nylander et al, 1995). Big deletions have been reported in other studies of SCCHN (Ahomadegbe et al, 1995;Magnusson et al, 1995;Zariwala et al, 1994) as well as in other tumours, such as colon cancer, breast cancer, leukaemia and oesophageal carcinoma (Jego et al, 1993;Huang et al, 1994).…”

“…In SCCHN, mutations in the p53 gene have been found in around 40-50% of the tumours (Boyle et al, 1993;Brachman et al, 1992;Brennan et al, 1995;Nylander et al, 1995).…”

p53 and Rb1 protein expression: are they prognostically useful in colorectal cancer?

“…However, in multivariate Cox proportional hazards analysis, the prognostic effect of aberrant Rbl protein expression failed to achieve independent prognostic significance. (Iggo et al, 1990 (Dunn et al, 1993;Baas et al, 1994Baas et al, , 1996McManus et al, 1994;Kocialkowski et al, 1995;Nylander et al, 1995). It has been stated that mutation of the p53 gene is one of the commonest mutations in human cancers, although mutations of p53 occur late in the adenoma-carcinoma sequence of colorectal cancer (Fearon and Vogelstein, 1990).…”

“…Mutant forms of p53 no longer possess the ability to arrest cell growth and induce apoptosis (Michalovitz et al, 1990) and are unable to bind specific DNA response sequences and to activate the transcription of genes with an adjacent p53 recognition sequence (Kern et al, 1992). Much interest was aroused by initial studies that showed that expression of p53 protein correlated with p53 gene mutations (Iggo et al, 1990), although subsequent studies have shown that immunohistochemical expression of p53 may also occur in the absence of p53 gene mutations (Dunn et al, 1993;Kocialkowski et al, 1995;McManus et al, 1994;Nylander et al, 1995). p53 mutations are thought to be a late event in the adenoma-carcinoma sequence in colorectal cancer (Fearon and Vogelstein, 1990).…”

Prognostic value of p53 mutations, bax, and spontaneous apoptosis in maxillary sinus squamous cell carcinoma

“…9,[15][16][17] In head and neck squamous cell carcinoma (SCC), a number of reports have documented overexpression of p53 protein 18 -21 and p53 gene mutation. 16,19,[22][23][24][25] However, conflicting results have been presented with regard to the correlation between prognosis and overexpression of p53. Some studies showed no correlation, 19,26 -28 whereas others showed a significant correlation between p53 expression and prognosis.…”