[Main factors affecting the effect of photodynamic therapy against human esophageal cancer cells in vitro].
OBJECTIVE
To evaluate the tumor cell-killing effect of photodynamic therapy against human esophageal cancer cells in vitro and identify the main factors affecting the effect.


METHODS
Human esophageal cancer Eca-109 cells were incubated for 24 h in vitro with hematoporphyrin derivative (HpD) and Photofrin at different concentrations prior to exposure to a light energy density of 15 J/cm(2) delivered from a DIOMED 630 PDT system. The cell killing effect was also evaluated for different HpD concentrations combined with 3 light energy densities (10, 30, and 50 J/cm(2)), respectively. The cell survival rate was measured using MTT assay, and fluorescence spectrometry was used to detect the intracellular photosensitizer fluorescence of the tumor cells after incubation with HpD for 4 h.


RESULTS
The cell survival rate after incubation with the two photosensitizers at different concentrations were significantly different, and under the 3 different light energy densities, incubation of the cells with different HpD concentrations also resulted in significantly different cell survival rates (P<0.05). At the 4 low photosensitizer concentrations and with different light energy densities, the cell survival rates were similar (P>0.05), but the 4 higher photosensitizer concentrations resulted in significant difference in the cells survival (P<0.05). Correlation analysis showed that the intracellular photosensitizer concentration was positively correlated to the photosensitizer concentrations in cell incubation (r=0.997).


CONCLUSIONS
When the light source remains constant, the light energy density, the kinds of photosensitizers and their concentrations are the main factors affecting the Eca-109 cell-killing effect of PDT.
Chen
Xiao-hua
XH
Center of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. cxh0663@yahoo.com.cn
Luo
Rong-cheng
RC
Li
Li-bo
LB
Ding
Xue-mei
XM
Lü
Cheng-wei
CW
Zhou
Xiao-ping
XP
Yan
Xiao
X
D045744:Cell Line, Tumor; D002470:Cell Survival; D017323:Dihematoporphyrin Ether / Q000494:pharmacology; D004938:Esophageal Neoplasms / Q000188:drug therapy*; D017324:Hematoporphyrin Derivative / Q000494:pharmacology; D006414:Hematoporphyrin Photoradiation; D006801:Humans; D008027:Light; D017319:Photosensitizing Agents / Q000494:pharmacology*
D017319:Photosensitizing Agents; D017324:Hematoporphyrin Derivative; D017323:Dihematoporphyrin Ether