DNA repair genes polymorphisms in multiple myeloma: no association with XRCC1 (Arg399Gln) polymorphism, but the XRCC4 (VNTR in intron 3 and G-1394T) and XPD (Lys751Gln) polymorphisms is associated with the disease in Turkish patients

Figures & data

Table 1. XRCC1 (A399G), XPD (−751), XRCC4 (VNTR in intron 3 and G-1394T) primer sequences, restriction enzymes and amplification conditions (on over night incubation)

Repair genes	Primer sequence	Annealing	Restriction enzyme and conditions
XRCC1 (Arg399Gln)	5′-AGT AGT CTG CTG GCT CTG G-3′, 5′-TCT CCC TTG GTC TCC AAC CT-3	55°C ve 32 cycles	Msp1, 37°C – ON and 2% agarose
XPD (Lys751Gln)	5′-ATC CTG TCC CTA CTG GCC ATT C-3′, 5′-TGT GGA CGT GAC AGT GAG AAA T-3′	60°C ve 32 cycles	Pst1, 37°C – ON and 2·5% agarose
XRCC4 (VNTR in intron 3)	5′-TCC TGT TAC CAT TTC AGT GTT AT-3′, 5′-CAC CTG TGT TCA ATT CCA GCT T-3′	55°C ve 32 cycles	3% agarose
XRCC4 (G-1394T)	5′-GAT GCG AAC TCA AAG ATA CTG A-3′, 5′-TGT AAA GCC AGT ACT CAA ACT T-3′	55°C ve 32 cycles	HincII, 37°C – ON and 2·5% agarose

Table 2. Clinical characteristics and treatment regimens of multiple myeloma patients

		Multiple myeloma		Healthy control
		Median	n* (%)	n* (%)
Age		59 (36–80)		41 (20–66)
Gender	Female/male		26/34 (43/57)	33/37 (47/53)
Ig subtypes	κ/λ		44/16 (73/27)
	G/A		36/24 (60/40)
	Light chain		10 (17)
Stage (Salmon–Durie)	II/III		19/41 (32/68)
	A/B		45/15 (75/25)
IPI	I		16 (27)
	II/III		23/21 (38/35)
ECOG	>1		14 (23)
Hemoglobin	g/dl	9·8 (6·0–14·7)
Leukocytes	μl	6770 (1620–15160)
Trombocytes	10^3/μl	167 (26–700)
C-reactive protein	mg/dl	6·65 (2·9–70)
LDH	IU/l	386 (164–2540)
b2-microglobulin	mg/l	4·2 (1·7–27)
Albumin	g/l	3·3 (2·1–4·7)
Treatment (n = 52)	1st line (VAD, MP)		47/5
	2nd line (ASCT/T, BODEC, TD)		17/17/13
	3rd line (ASCT/T, BODEC, TD)		6/15/3
Mortality			18 (30)
Median follow-up (months)		30·2 (6·6–85·2)

Note: *n = 60.

VAD, vincristine, adriamycin and dexamethasone; MP, melphalan, prednisolone; BODEC, bortezomib, dexamethasone, cyclosphosphamide; TD, thalidomide, dexamethasone; ASCT, autologous stem cell transplantation; ECOG, performance evaluation at diagnosis; LDH, lactic dehydrogenase; IPI, International prognostic index.

Table 3. Comparison of genotype of XPD, XRCC1, XRCC4 gene polymorphisms between patients with multiple myeloma and healthy controls

	Genotype	MM	Healthy control	OR	95%CI	P
		n* (%)	n† (%)
XPD	AA	25 (41·7)	37 (52·9)	0·520	0·157–1·719	0·283
(Arg399Gln)	AC	24 (40·0)	24 (34·3)	1·066	0·310–3·669	0·919
	CC	11 (18·3)	9 (12·8)	0·657	0·252–1·713	0·468
XRCC1	AA	23 (38·3)	25 (35·7)	1·005	0·351–2·879	0·993
(Lys751Gln)	AG	20 (33·3)	24 (34·3)	1·167	0·404–3·374	0·776
	GG	17 (28·4)	21 (30)	1·084	0·507–2·316	0·849
XRCC4	DD	1 (1·7)	10 (14·3)	0·043	0·004–0·504	0·012
(VNTR in intron 3)	DI	36 (60·0)	42 (60)	1·000	0·495–2·022	1·000
	II	23 (38·3)	18 (25·7)	0·390	0·145–1·047	0·062
XRCC4	GG	20 (33·3)	17 (24·3)	4·398	1·338–14·461	0·015
(G-1394T)	GT	27 (45·0)	26 (37·1)	0·722	0·358–1·458	0·377
	TT	13 (21·7)	27 (38·6)	4·481	1·427–14·074	0·010

Note: *n = 60.

†n = 70.

‡OR (95%CI) was adjusted by age and sex.

§Fisher’s Exact Test.

Figure 1. Kaplan–Meier plots on overall survival (OS) time according to the type of IPI risk score at diagnosis.

Figure 2. Kaplan–Meier plots on event-free survival (EFS) time according to the type of XPD (Lys751Gln) genotypes.

Table 4. Initial treatment modalities and treatment response of myeloma patients

		n	Median OS mo (6 yr %)	Log rank P value	Median EFS mo (6 yr %)	Log rank P value
All patients		52	65		34·5
Initial treatment	VAD+ASCT	17	73·4		38·8
	VAD or M+BODEC	16	(61)		20·6
	VAD or M+TD	13	65	0·279	33·5	0·324
Initial treatment	CR	15	73·2		62·7
Response	VGPR	9	(88)		57·3
	PR	16	37·9		24·6
	SD+PROG	6	56·3	0·050	14·8	0·005

Note: OS, overall survival; EFS, event-free survival; VAD, vincristine, adriamycin and dexamethasone; MP, melphalan, prednisolone; BODEC, bortezomib, dexamethasone, cyclosphosphamide; TD, thalidomide, dexamethasone; ASCT, autologous stem cell transplantation.

Table 5. Univariate analysis (Log rank test) of XPD, XRCC1, XRCC4 − intron 3 and XRCC4 – 1394 Gene Polymorphisms in the patients with multiple myeloma

		n	Median OS mo (6 yr %)	Log rank P value	Median EFS mo (6 yr %)	Log rank P value
All patients		52	65		34·5
Gender	Female/male	21/31	(57)/65	0·908	30·1/48·7	0·028
Age	<65/⩾65	37/15	65/53·2	0·671	34·5/35	0·375
Stage (Salmon–Durie)	II/III	19/33	(81)/56·3	0·148	33·5/48·7	0·155
	A/B	39/13	73·2/65	0·139	40·2/33·5	0·392
IPI (ISS)	I	14	(86)		57·3
	II	19	(56)		33·5
	III	19	56·3	0·044	29·7	0·131
Ig subtypes	κ/λ	38/14	67·1/73·4	0·182	35/20·6	0·300
	G	30	65		35
	A	12	67·1		67·1
	Light chain	10	73·4	0·744	29·4	0·232
ECOG	⩽1/>1	43/9	73·2/53·2	0·037	33·5/48·7	0·452
Platelets (×10^9/l)	<150/⩾150	14/38	37·9/73·2	0·033	24·6/38·8	0·479
LDH (IU/l)	<480/⩾480	41/11	53·2/67·1	0·278	34·5/38·8	0·352
C-reactive protein (mg/l)	<5/⩾5	19/33	37·9/65	0·497	35/38·8	0·820
Initial treatment	VAD+ASCT	17	73·4		38·8
	VAD or M+BODEC	16	(61)		20·6
	VAD or M+TD	13	65	0·279	33·5	0·324
Initial treatment	CR	15	73·2		62·7
Response	VGPR	9	(88)		57·3
	PR	16	37·9		24·6
	SD+PROG	6	56·3	0·050	14·8	0·005
XPD (Lys751Gln)	AA	21	73·2		48·7
	AC	20	37·9		30·1
	CC	11	67·1	0·136	20·6	0·137
	AA/AC, CC	21/31	73·2/56·3	0·061	29·7/47·7	0·047
XRCC1 (Arg399Gln)	AA	19	65		48·7
	AG	18	56·3		27·2
	GG	15	67·1	0·236	35	0·081
	AA/AG, GG	19/33	65/56·3	0·116	29·7/47·7	0·067
XRCC4 – intron 3	DD	1	73·2		62·7
	DI	32	56·3		34·5
	II	19	65	0·980	38·8	0·867
XRCC4 (G-1394T)	GG	19	63		35
	GT	21	56·3		29·7
	TT	12	65	0·238	62·7	0·194

Note: *Median (year).

OS, overall survival; EFS, event-free survival; VAD, vincristine, adriamycin and dexamethasone; MP, melphalan, prednisolone; BODEC, bortezomib, dexamethasone, cyclosphosphamide; TD, thalidomide, dexamethasone; ASCT, autologous stem cell transplantation; ECOG, performance evaluation at diagnosis; LDH, lactic dehydrogenase; IPI; International prognostic index.