Objective  To investigate the in vitro and in vivo effects of HP-10

a hexa-peptide β-Ala-Arg-Leu-Arg-Trp-Arg

on the proliferation of human colon adenocarcinoma LoVo cells and the penetration ability of HP-10 into the LoVo cells.   Methods  MTT assays were used to identify the effects of HP-10 on the LoVo cells at 75

37.5 or 18.75 μmol/L. The membrane permeable effect of HP-10

the cell cycle and apoptosis were determined by confocal laser fluorescence microscopy and flow cytometry respectively. Then the model of colon cancer of nude mice was established with implantation of LoVo cells (3×10

6

) and the therapeutic effect of HP-10

at concentrations of 750

375 and 75 μmol/L respectively was observed.   Results  HP-10 markedly inhibited the proliferation of LoVo cells in a dose-dependent manner (P0.05). HP-10 was able to transduce directly into LoVo cells and further induce cell apoptosis (P0.05)

but had no effect on cell cycle (P0.05). Moreover

the growth of tumors was inhibited obviously by HP-10 in this adenocarcinoma model (P0.05).   Conclusion  HP-10 is an oligopeptide able to directly transduce into cells without the coupling cell-penetrating peptide. It can inhibit the growth of LoVo cells in vitro and in vivo through inducing cell apoptosis.