Mitochondrial microsatellite instability in gastric cancer and its precancerous lesions

Table 1 Sequences of primer for PCR analysis

Repeatsequence	mtDNAregion	Position	Annealing(°C)	Primer (5’-3’)
(C)n	270-425	D-loop	58	TCCACACAGACATCAATAACA AAAGTGCATACCGCCAAAAG
(CA)n	467-556	D-loop	55	CCCATACTACTAATCTCATCAA TTTGGTTGGTTCGGGGTATG
(C)6	3 529-3 617	ND1	55	CCGACCTTAGCTCTCACCAT AATAGGAGGCCTAGGTTGAG
(A)7	4 555-4 644	ND2	55	CCTGAGTAGGCCTAGAAATAAA ACTTGATGGCAGCTTCTGTG
(T)7	9 431-9 526	COIII	55	CCAAAAAGGCCTTCGATACG GCTAGGCTGGAGTGGTAAAA
(C)6 and (A)8	12 360-12 465	ND5	55	CACCCTAACCCTGACTTCC GGTGGATGCGACAATGGATT
(CCT)3 and (AGC)3	12 940-13 032	ND5	55	GCCCTTCTAAACGCTAATCC TCAGGGGTGGAGACCTAATT

Table 2 mtMSI in gastric cancer and its precursor

	n	mtMSI(%)
Chronic gastritis	40	5(12.5)
Intestinal metaplasia	30	6(20.0)
Dysplasia	20	5(25.0)
Gastric cancer	68	26(38.2)

Table 3 Characteristics of 68 gastric cancer patients

Characteristic	n	mtMSI-positive	tMSI-negative
Age
<40 years	15	5	10
>40 years	53	21	32
Sex
Male	42	15	27
Female	26	11	15
Size
<5 cm	38	14	24
>5 cm	30	12	18
Histological type
Intestinal	41	22b	19
Diffuse	27	4	23
Tumor location
Distal	45	23c	22
Proximal	23	3	20
Invasion
Within the wall	33	12	21
Invading serosa	35	14	21
Lymph node spread
Absent	30	11	19
Present	38	15	23

^bP=0.001 vs the groups of diffuse type and

^cP=0.002 vs the groups of proximal loation.