Abstract: Objective To investigate the effect of 17-AAG combined with paclitaxel (PTX) on the proliferation and apoptosis of
esophageal squamous cell carcinoma cell line Eca-109 in vitro. Methods Eca-109 cells were treated with 17-AAG and PTX either
alone or in combination. The proliferation of Eca-109 cells was detected by MTT assay, and the cell cycle changes and cell
apoptosis were determined by flow cytometry. Results Compared with the control group, both 17-AAG and PTX significantly
inhibited the proliferation of Eca-109 cells. A combined treatment of the cells with 0.5 μmol/L PTX and 0.625 μmol/L 17-AAG
produced an obviously stronger inhibitory effect on the cell proliferation than either of the agents used alone (P<0.01). Flow
cytometry showed that, 17-AAG and PTX used alone caused Eca-109 cell cycle arrest in G2/M phase and S phase, respectively,
and their combined use caused cell cycle arrest in both G2/M and S phases. The cell apoptosis rates of Eca-109 cells treated with
17-AAG, PTX and their combination were 4.52%, 10.91%, and 29.88%, respectively, all significantly higher than that in the
control group (1.32%); the combined treatment resulted in a distinct apoptotic peak that was significantly higher than that
caused by either of the agents alone. Conclusion 17-AAG and PTX can inhibit cell proliferation and promote apoptosis of
Eca-109 cells, and their combination produces stronger effects in inhibiting cell proliferation and increasing cell apoptosis.