Loss of heterozygosity of Kras2 gene on 12p12-13 in Chinese colon carcinoma patients

Table 1 Primer sequences on 12p12-13 microsatellite markers

Markers	Primer sequences	Length(bp)
D12S89	D12S89-F:5’-ATTTGAGAGCAGCGTGTTTT-3’	254-288
	D12S89-R:5’-CCATTATGGGGAGTAGGGGT-3’
D12s358	D12s358-F:5’-GCCTTTGGGAAACTTTGG-3’	238-270
	D12s358-R:5’-TAAGCCCTTTTATTTTTCCTAAC-3’
D12s310	D12s310-F:5’-GAAAACTAATTGCCCCTTAC-3’	243-253
	D12s310-R:5’-TTTAGATTCTCCAAATGCC-3’
D12S1606	D12S1606-F:5’-ATGAGAGGCCAAATTAAAG-3’	271-279
	D12S1606-R:5’-CTACTGTTGTGTCAGGGTCA-3’
D12s1596	D12s1596-F:5’-TCATGTGGCTGGTAGAGAAG-3’	204-222
	D12s1596-R:5’-CGTGAAGCAGATTTATCGTG-3’
D12s1617	D12s1617-F:5’-AGCCTGAGGGGCCACAT-3’	215-261
	D12s1617-R:5’-TGGGCAACTTGGATAAGAAACA-3’
D12s1592	D12s1592-F:5’-GCTGAGTGTGGTGGCAC-3’	238-280
	D12s1592-R:5’-GAGACTATTCCAACAGTGTATTTTC-3’
D12S1057	D12S1057-F:5’-AGAGACAGAAGCAGTAGGATGG-3’	227
	D12S1057-R:5’-GGTTCTGACGTTTTAAGACTCG-3’
D12S1591	D12S1591-F:5’-GCGCTTTGTACTATGTTACATTT-3’	234-276
	D12S1591-R:5’-GAAGACGTTGGGTGAATC-3’
D12S823	D12S823-F:5’-GGGCAATAGAGTGAGATTCTG-3’	119
	D12S823-R:5’-CCTACCTCCTTCCCCATCC-3’
D12S1034	D12S1034-F:5’-TTTTCAAAAAGTGTGACTGTGC-3’	280-302
	D12S1034-R:5’-CAGCCTAGTAAAAAATTTAAATTGG-3’

Table 2 Frequency of LOH on the 11 markers of 12p12-13 in colon carcinoma and its adjacent tissues

Adjacent tumor tissue					Tumor tissue
Markers	LOH (n)	Signal (n)	Frequency ofLOH (%)	Heterozygo-sity (%)	LOH (n)	Signal (n)	Frequency ofLOH (%)	Heterozy-gosity (%)
D12S823	0	5	0	50	1	5	20	50
D12S1034	2	7	28.57	70	3	7	42.88	70
D12S1596	1	4	25	40	1	4	25	40
D12S1591	1	7	14.29	70	3	7	42.88	70
D12S358	0	8	0	80	2	8	25	80
D12S310	0	3	0	30	1	3	33.33	30
D12S1592	0	4	0	40	0	4	0	40
D12S89	1	8	12.5	80	1	8	12.5	80
D12S1617	1	7	14.29	70	1	7	14.29	70
D12S1057	0	7	0	70	2	7	28.57	70
D12S1606	0	6	0	60	1	6	16.67	60

Table 3 Distribution of LOH on 12p12-13 in microsatellite-labeled primers

	1		2		3		4		5		6		7		8		9		10
Biomarker	A	T	A	T	A	T	A	T	A	T	A	T	A	T	A	T	A	T	A	T
D12S823	○	○	◎	◎	◎	◎	○	○	○	○	◎	◎	◎	●	○	○	◎	◎	○	○
D12S1034	◎	◎	○	○	●	●	○	○	◎	◎	◎	◎	◎	●	○	○	◎	◎	●	●
D12S1596	◎	◎	◎	◎	○	○	○	○	○	○	○	○	●	●	○	○	○	○	◎	◎
D12S1591	○	○	◎	●	◎	◎	○	○	◎	◎	○	○	●	●	◎	◎	◎	◎	◎	●
D12S358	◎	◎	○	○	◎	◎	○	○	◎	◎	◎	◎	◎	●	◎	◎	◎	●	◎	◎
D12S310	◎	◎	○	○	○	○	○	○	○	○	○	○	○	○	◎	●	○	○	◎	○
D12S1592	○	○	◎	◎	○	○	○	○	◎	◎	○	○	◎	◎	◎	◎	○	○	○	○
D12S89	◎	◎	◎	◎	◎	◎	○	○	◎	◎	◎	◎	●	○	◎	●	○	○	◎	◎
D12S1617	○	○	◎	◎	◎	◎	○	○	◎	◎	◎	◎	●	●	◎	◎	○	○	◎	◎
D12S1057	◎	◎	◎	◎	◎	◎	○	○	○	○	◎	◎	◎	●	◎	◎	◎	●	○	○
D12S1606	◎	◎	○	○	◎	◎	○	○	◎	◎	○	○	◎	◎	◎	◎	○	○	◎	●

◎: Normal; ○: No signal; ●: LOH; A: adjacent tissue T: cancer tissue

Table 4 Correlation between LOH on chromosome 12p12-13 and clinical pathologic factors

Clinical character	LOH		Total	Ratio (%)	P
	+	-
Tissue class
Adjacent Tumor	3	7	10	30	0.17753
Tumor	6	4	10	60
Age (yr)
≤50	4	3	7	70	0.77816
>50	2	1	3	30
Sex
Male	5	2	7	70	0.25979
Female	1	2	3	30
Tumor size (cm)
<5	3	1	4	40	0.42919
≥5	3	3	6	60
Lymph node matastasis
Yes	4	2	6	60	0.598161
No	2	2	4	40