Histone deacetylase inhibitor pre-treatment enhances the efficacy of DNA-interacting chemotherapeutic drugs in gastric cancer

Table 1 List of primers used for carrying out real-time PCR on different genes

Gene	Forward primer, 5`-3`	Reverse primer, 5`-3`
RPS13	GCTCTCCTTTCGTTGCCTGA	ACTTCAACCAAGTGGGGACG
HDAC1	ATATCGTCTTGGCCATCCTG	TGAAGCAACCTAACCGATCC
HDAC2	GGGAATACTTTCCTGGCACA	ACGGATTGTGTAGCCACCTC
HDAC3	TGGCATTGACCCATAGCCTG	GCATATTGGTGGGGCTGACT
HDAC4	TCGCTACTGGTACGGGAAAAC	AGAGGGAAGTCATCTTTGGCG
HDAC5	ACTGTTCTCAGATGCCCAGC	TGGTGAAGAGGTGCTTGACG
HDAC6	AGTGGCCGCATTATCCTTATCC	ATCTGCGATGGACTTGGATGG
HDAC7	TTCCTGAGTGCAGGGGTAGT	CATCGCCAGGAGGTTGATGT
HDAC8	ATAACCTTGCCAACACGGCT	CTTGGCGTGATTTCCAGCAC
HDAC9	ACTGAAGCAACCAGGCAGTC	TTCACAGCCCCAACTTGTCC
HDAC10	CTGGCCTTTGAGGGGCAAAT	CAGCAGCGTCTGTACTGTCA
HDAC11	CCGGAAAATGGGGCAAAGTG	TAAGATAGCGCCTCGTGTGC
p27-CDKN1B	TTGGGGCAAAAATCCGAGGT	TGTGTTTACACAGCCCGAAGT
p21-CDKN1A	GCGACTGTGATGCGCTAATG	GAAGGTAGAGCTTGGGCAGG
p16-CDKN2A	ACTTCAGGGGTGCCACATTC	CGACCCTGTCCCTCAAATCC

Table 2 Regime-specific synergistic, additive or antagonistic effects of chemotherapeutic drugs and histone deacetylase inhibitors

Drugs	Treatment sequence and result of FA and median effect plot analysis		FA
			0.5	0.75	0.95
Cisplatin and VPA	Pre	Dose of Cis, VPA (µmol/L)	0.965, 386.359	2.711, 1084.65	15.361, 6144.61
		CI	0.352	0.471	0.784
	Concurrent	Dose of Cis, VPA (µmol/L)	0.705, 282.387	3.874, 1549.74	67.690, 27076.0
		CI	0.257	0.673	3.454
	Post	Dose of Cis, VPA (µmol/L)	3.254 ,1301.90	9.362, 3745.16	55.260, 22104.1
		CI	1.188	1.627	2.820
Oxaliplatin and VPA	Pre	Dose of Oxa, VPA (µmol/L)	0.788, 394.469	2.094, 1047.04	10.796, 5398.39
		CI	0.404	0.453	0.552
	Concurrent	Dose of Oxa, VPA (µmol/L)	1.533, 766.633	4.305, 2152.92	24.406, 12203.2
		CI	0.786	0.933	1.249
	Post	Dose of Oxa, VPA (µmol/L)	2.362, 1181.47	8.451, 4225.64	71.917, 35958.6
		CI	1.211	1.83182	3.68265
Epirubicin and TSA	Pre	Combined dose (µg)	0.030, 0.300	0.093, 0.931	0.623, 6.231
		CI	0.645	0.727	1.222
	Concurrent	Combined dose (µg)	0.129, 1.299	0.410, 4.105	2.835, 28.356
		CI	2.789	3.207	5.563
	Post	Combined dose (µg)	0.137, 1.375	0.301, 3.010	1.122, 11.220
		CI	2.952	2.351	2.201

FA: Fraction affected; Pre: Pre-treatment; Post: Post-treatment; TSA: Trichostatin A; Cis: Cisplatin; VPA: Valproic acid; Oxa: Oxaliplatin; CI: Combination index. Dose at Fa-0.5 for VPA- 1827.79, TSA-1.50, Cisplatin-6.84, Oxaliplatin-4.18 and Epirubicin- 0.07; Dose at Fa-0.75 for VPA- 4165.97, TSA-2.61, Cisplatin-12.85, Oxaliplatin-10.33 and Epirubicin- 0.25; Dose at Fa 0.95 for VPA- 16628.5, TSA-6.56, Cisplatin-37.06, Oxaliplatin-47.30, and Epirubicin- 2.29.