Loss of heterozygosity at adenomatous polyposis coli, mutation in colorectal cancer and deleted in colorectal cancer genetic loci in colorectal cancers

Table 1 Primer sets used in polymerase chain reaction-loss of heterozygosity assays

Primer set1	Priming region	Amplification size (base pairs)	Polymorphism type	Primer sequence
1	APC exon 11	133	Rsal RFLP	5'-GGACTACAGGCCATTGCAGAA-3'
				5'-GGCTACATCTCCAAAAGTCAA-3'
2	MCC exon 10	79 or 93	Insertion	5'-TACGAATCCAATGCCACA-3'
				5'-CTGAAGTAGCTCCAAACA-3'
3	DCC	396	MspI RFLP	5'-TTGCACCATGCTGAAGATTGT-3'
				5'-ACCCTCCCCCTGATGACTTA-3'
4	DCC	240	MspI RFLP	5'-CGACTCGATCCTACAAAATC-3'
				5'-TCTACCCAGGTCTCAGAG-3'
5	DCC	200	VNTR	5'-GATGACATTTTCCCTCTAG-3'
				5'-GTGGTTATTGCCTTGAAAAG-3'

¹Primer sets 1 and 2, Tumura et al[6]; Primer sets 3, 4, and 5, Gao et al[5]. VNTR: Variable number of tandem repeats; APC: Adenomatous polyposis coli; MCC: Mutation in colorectal cancer; DCC: Deleted in colorectal cancer; RFLP: Restriction fragment length polymorphism analysis technique; RFLP: Restriction fragment length polymorphism.

Table 2 Results of loss of heterozygosity assay at the adenomatous polyposis coli, mutation in colorectal cancer and deleted in colorectal cancer genetic loci in 41 colorectal carcinomas

Number	APC exon 11	MCC exon 10	DCC
1	HET	NI	NI
2, 6, 12, 23	HET	NI	HET
3, 5, 7, 30, 32	HET	NI	LON
4	LOH	HET	NI
8, 19, 24, 25, 31	NI	HET	LOH
9, 11, 21	HET	LOH	LOH
10, 28, 37	HET	HET	HET
13	LOH	LOH	HET
14, 33, 40	LOH	NI	HET
15, 22, 34, 38	NI	NI	LOH
16, 20, 39	NI	HET	HET
17	NI	LOH	NI
18, 29	NI	LOH	HET
26	HET	LOH	HET
27	HET	HET	LOH
35	LOH	NI	LOH
36	LOH	HET	LOH
41	NI	NI	HET

APC: Adenomatous polyposis coli; MCC: Mutation in colorectal cancer; DCC: Deleted in colorectal cancer; HET: Retained heterozygosity; NI: Not informative; LOH: Loss of heterozygosity.

Table 3 Correlation between loss of heterozygosity at the adenomatous polyposis coli, mutation in colorectal cancer and deleted in colorectal cancer genes and clinicopathological parameters of colorectal cancers

Group	LOH/ Informative (%)
	APC	MCC	DCC
Grade (differentiation)
Well/Moderate	4/14 (28.6)	4/12 (33.3)	8/20 (40.0)
Low differentiated	2/8 (25.0)	3/6 (50.0)	10/14 (71.4)
Mucoid	1/3 (33.3)	1/4 (25.0)	3/4 (75.0)
Size
≤ 3 cm	3/8 (37.5)	4/12 (33.3)	7/15 (46.6)
> 3 cm	4/17 (23.5)	4/10 (40.0)	14/23 (60.9)
Serosal invasion
Negative	5/16 (37.5)	4/14 (28.5)	10/23 (43.4)
Positive	2/9 (22.2)	4/9 (50.0)	11/15 (73.3)
Lymph-node metastasis
Negative	4/16 (25.0)	5/14 (35.7)	9/23 (39.1)
Positive	3/9 (33.3)	3/8 (37.5)	12/15 (80.0)a
Dukes' stages
Stages I and II	4/14 (28.5)	4/10 (40.0)	6/17 (35.3)
Stages III and IV	3/11 (27.3)	4/12 (33.3)	15/21 (71.4)

^aP < 0.05. LOH: Loss of heterozygosity; APC: Adenomatous polyposis coli; MCC: Mutation in colorectal cancer; DCC: Deleted in colorectal cancer