The tumor affinity of chlorin e6 and its sonodynamic effects on non-small cell lung cancer.
OBJECTIVE
Sonodynamic therapy (SDT) is a promising new approach for cancer therapy. The aim of this study was to investigate the tumor affinity of chlorin e6, a photosensitizer, and its sonodynamic effects on NSCLC.


METHODS
Human lung adenocarcinoma cells SPCA-1 and mice bearing SPCA-1 tumor xenograft were exposed to ultrasound in the presence or absence of chlorin e6. Chlorin e6 distribution was detected by laser scan confocal microscope. Cell apoptosis and necrosis were studied by flow cytometry analysis. Tumor size and weight were measured after different treatments.


RESULTS
The concentration of chlorin e6 in tumor tissue was remarkably higher than that in normal muscle near tumor, and the difference was greatest at 18h (the fluorescence intensity was 5.38-fold higher in tumor than in muscle, P<0.05). In vivo, ultrasound (0.4-1.6W/cm(2)) or chlorin e6 (10-40mg/kg) alone had no remarkable anti-tumor effects, but the combination of ultrasound (1.6W/cm(2)) with chlorin e6 (SDT) hampered tumor growth significantly (P<0.05). Intraperitoneal injection of 40mg/kg chlorin e6 exerted no notable side effect on blood, liver and kidney function. Flow cytometry analysis showed that chlorin e6-mediated sonodynamic effect was mainly through the induction of cell necrosis.


CONCLUSIONS
Chlorin e6 is a promising sonosensitizer and chlorin e6-mediated SDT may provide a new approach for NSCLC therapy.
Department of Oncology, Guangzhou General Hospital of Guangzhou Military Command, Guangzhou, Guangdong 510010, PR China. bzcheese@hotmail.com
Bei
B
Chen
Ruinian
R
Zheng
Duan
D
Liu
Baofeng
B
Li
Jinrong
J
Lin
Weimin
W
Zhang
D000230:Adenocarcinoma / Q000188:drug therapy / Q000473:pathology* / Q000628:therapy; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D002735:Chlorophyllides; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000628:therapy; D051379:Mice; D011166:Porphyrins / Q000494:pharmacology* / Q000627:therapeutic use; D014464:Ultrasonic Therapy; D023041:Xenograft Model Antitumor Assays
D000970:Antineoplastic Agents; D002735:Chlorophyllides; D011166:Porphyrins; C062985:phytochlorin