ABSTRACT
Objective To investigate the expression of sphingosine kinase 1(SphK1)and NF-κB in colon carcinoma tissues and their correlation with clinicopathologic features.Methods Sixty-six paraffinembedded colon carcinoma samples and 66 fresh colon carcinoma samples were tested using immunohistochemistry,RT-PCR and Western blot,respectively.Results In 66 fresh colon carcinoma samples,the positive rate of SphK1 and NF-κB mRNA expression were 84.85％(56/66)and 74.24％(49/66),while the positive rate of SphK1 and NF-κB protein detected by Western blot were 78.79％(52/66)and 69.70％(46/66).The positive rates were higher than those in the adjacent tissues[mRNA:63.64％(42/66),48.49％(32/66);protein:57.58％(38/66),45.45％(30/66)]and the normal mucosa [mRNA:42.42％(28/66),25.76％(17/66); protein:36.36％(24/66),24.24％(16/66)],with statistical significances(all P values ＜ 0.05).The mean expressive levels of SphK1 and NF-kB mRNA and protein in colon carcinoma were both significantly higher than those in the adjacent tissues and the normal mucosa(mRNA:0.55±0.06 vs0.35 ±0.05 vs0.25±0.05,0.75 ±0.06 vs0.43±0.05 vs0.30±0.04 ; protein:0.77 ± 0.05 vs 0.38 ± 0.06 vs 0.12 ± 0.03,0.45 ± 0.08 vs 0.23 ± 0.05 vs 0.13 ± 0.03 ;all P values ＜ 0.05).There was a close correlation between SphK1 and NF-kB expression levels (r =0.459,P =0.036).The results of immunohistochemistry were similar to those of RT-PCR and Western blot.Overexpression of SphK1 and NF-κB in colon carcinoma was related with depth of invasion,distant and lymph node metastasis and Dukes'stages(all P values ＜0.05).The expression of SphK1 was also related with differentiation(P ＜ 0.05).Conclusions Overexpression of SphK1 and NF-κB may be involved in the pathogenesis and progression of colon carcinoma.Moreover,SphK1 and NF-κB may be correlated with the invasion and metastasis of colon carcinoma.