title: Efficacy of 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a in photodynamic therapy of human esophageal squamous cancer cells.
abstract: The present study investigated the effects of 2-(1-hexyloxyethyl)-2-devinylpyro pheophorbide-a (HPPH)-mediated photodynamic therapy (PDT) onin vitrocell survival andin vivotumor growth derived from human esophageal squamous cancer cells (Eca109). A cell counting kit 8 (CCK8) assay was used to assess the phototoxicity of HPPH-mediated PDT in cultured Eca109 cells. The inhibition of tumor growth was determined by the changes in the relative tumor volume (RTV) and tumor weight. The results revealed that HPPH, in the range of 0.005-1 μg/ml, exhibited no cytotoxicity in the Eca109 cells without light exposure and that thein vitroefficiency of HPPH-mediated PDT was higher compared with that of Photofrin®-mediated PDT. Thein vivoresults indicated that graded doses of HPPH-mediated PDT significantly inhibited the xenograft tumor growth derived from the Eca109 cells in a dose-dependent manner. The inhibition efficacy of 0.6 and 1.0 mg/kg HPPH-mediated PDT was similar to that of 10 mg/kg Photofrin-mediated PDT. Furthermore, HPPH possessed a lower toxicity than Photofrin at the dose that achieved the same efficacy in mice bearing Eca109 subcutaneous tumors. The histopathological findings indicated that the tumor tissues in the photosensitizer (PS)-treated mice demonstrated varying degrees of necrosis. HPPH and Photofrin exhibited vascular cytotoxicity on the treated tumors. In conclusion, the present study demonstrated that the phototoxicity of HPPH-mediated PDT is higher than that of Photofrin-mediated PDT of the same dose. HPPH possessed lower toxicity than Photofrin at the dose that achieved the same efficacy. Therefore, HPPH may be a promising agent for treating human esophageal squamous cell cancer (ESCC).
authors.affiliation: Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangdong, Guangzhou 510080, P.R. China.
authors.forename: Dengpan
authors.initials: D
authors.lastname: Wu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.forename: Yanni
authors.initials: Y
authors.lastname: Fu
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Nan
authors.initials: N
authors.lastname: Tang
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.forename: Liang
authors.initials: L
authors.lastname: Tao
keywords: 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a photodynamic therapy; human esophageal squamous cell cancer