Objective  To detect the expression of pyruvate dehydrogenase kinase-I (PDK1) in human colon cancer tissue and cells and to study the effect of PDK1 on colon cancer cell activity.   Methods  Expression of PDK1 in human colon cancer tissue and its adjacent tissue and 4 PDK1 genes in human colon cancer cells was detected by RT-PCR

fluorescence quantitative PCR

immunofluorescence and Western blotting

respectively. Colon cancer cell activity induced by dichloroacetate (DCA)

a PDK1 specific inhibitor

was measured by MTT.   Results   The expression level of PDK1 gene was higher in colon cancer tissue than in its adjacent tissue. The 4 PDK1 genes were significantly expressed in human colon cancer cells. DCA inhibited the proliferation activity of colon cancer cells by suppressing PDK1 in a concentration-dependent manner. The activity rate of 90 mmol/L DCA for colon cancer cells was (23.90±2.79)%

(5.90±1.31)%

(32.82±4.50)% and (29.72±3.03)%

respectively.   Conclusion  The expression level of PDK1 gene is high in colon cancer tissue and cells

and low in its adjacent tissue. DCA can suppress the proliferation activity of colon cancer cells by inhibiting PDK1

thus PDK1 may become an effective target in therapy for colon cancer.