[Hematoporphyrin derivative-mediated photodynamic therapy for human colon carcinoma: a comparative study with LoVo and CoLo205 cells in vitro].

OBJECTIVE

To investigate the killing effect of photodynamic therapy (PDT) mediated by hematoporphyrin derivative (HpD) on human colon carcinoma LoVo and CoLo205 cells in vitro.

METHODS

LoVo and CoLo205 cells cultured in vitro were incubated in the presence of 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, and 4.0 microg/ml HpD for 4 h and exposed to different light doses delivered using a semiconductor laser at 630 nm with the energy density of 2, 5, 10, and 20 J/cm(2). After further culture for 24 h, the survival rate of LoVo and CoLo205 cells were analyzed by MTT assay, and the cellular fluorescence intensities of HpD were measured with a luminescence spectrometer.

RESULTS

HpD-PDT resulted in effective cell killing to a comparable magnitude in LoVo and CoLo205 cells cultured in vitro (P>0.05). The killing effects were positively correlated with the concentration of HpD and the dosage of laser irradiation. Exposure to 20 J/cm(2) resulted in an IC(50) of LoVo and CoLo205 cells of 0.4 and 0.6 microg/ml respectively, which were not significantly different (P>0.05). The cellular HpD fluorescence intensities were also similar between the two cells.

CONCLUSION

HpD-PDT may effectively kill LoVo and CoLo205 cells cultured in vitro.