['To investigate the effects of the Bcl-XL antisense oligodeoxynucleotides (ASODN) in suppressing the Bcl-XL expression and increasing the sensitivity of esophageal cancer cell line EC9706 to 5-fluorouracil (5-Fu).', 'The proliferation inhibitory rate of EC9706 was assessed by MTT, the expression of Bcl-XL was detected by RT-PCR and Western blot, and the apoptotic changes were examined by acridine orange (AO) fluorescent staining and flow cytometry, respectively.', 'In the group of ASODN combined with 5-Fu, the proliferation inhibitory rate of esophageal cancer cells was 71.58%, the expression inhibitory rate of Bcl-XL mRNA was 81.25%, the expression of Bcl-XL protein was decreased significantly. The apoptosis rates detected by AO fluorescent staining and flow cytometry were 69.5% and (63.32 +/- 9.23)%, respectively. There were significant differences as compared with the cell control group, the vacuity control group, the N-ODN group, the ASODN group and the 5-Fu group, respectively (P < 0.05).'] Does [ Bcl-XL antisense oligodeoxynucleotide sensitize human esophageal cancer cell line to 5-fluorouracil ]?