Co-mutation of p53, K-ras genes and accumulation of p53 protein and its correlation to clinicopathological features in rectal cancer

Table 1 Sequences of primers used in the study

Gene	Extron/codon	Sequences of primers	Product size
p53	Exons5-6	5’TGTTCACTTGTGCCCTGACT3’
		5’GGAGGGCCACTGACAACCA3’	489 bp
	Exon 7	5’GGCGACAGAGCGAGATTCCA3’
		5’GGGTCAGCGGCAAGCAGAGG3’	286 bp
	Exon 8	5’GACAAGGGTGGTTGGGAGTAGATG3’
		5’GCAAGGAAAGGTGATAAAAGTGAA3’	320 bp
K-ras	Codon 12-13	5’TCAAAGAATGGTCCTGCACC3’
		5’GCCTGCTGAAAATGACTGAA3’	178 bp

Table 2 Sensitivity of IHC to detect p53 gene mutation

p53 gene (PCR-SSCP)	p53 IHC staining (%)
	Negative	Positive
No mutation	21 (45.7)	25 (54.3)
Mutation	15 (29.4)	36 (70.6)

Table 3 Survival of 97 rectal cancer cases and its correlation to p53 and K-ras gene mutation

Survival (year)	p53 mutation		K-ras mutation		p53 and K-ras mutation
	(-)	(+)	(-)	(+)	Neither	Either	Both
1 -	86.52	95.83	91.04	91.53	81.25	93.48	93.44
2 -	77.04	82.30	87.79	75.37	71.48	86.55	72.29
3 -	67.25	73.16	74.79	67.93	54.17	79.44	65.06
4 -	64.33	62.32	66.91	61.36	54.17	71.08	56.38
5 -	64.33	62.32	66.91	61.36	54.17	71.08	56.38
P	0.5672		0.4536		0.2030