Apoptosis induced by hematoporphyrin monomethyl ether combined with He-Ne laser irradiation in vitro on canine breast cancer cells.
ABSTRACT Hematoporphyrin monomethyl ether (HMME) is a novel and promising porphyrin-related photosensitizer for photodynamic therapy (PDT). The aim of this study was to investigate HMME-induced apoptosis in CHMm cells, a canine breast cancer cell line. CHMm cells were treated with HMME and a He-Ne laser at a wavelength of 632.8 nm. Cell viability was determined using the trypan blue exclusion assay. Apoptosis was analyzed using Hoechst 33258, AO/EB, Annexin V/PI staining and single-cell gel electrophoresis (comet assay). Apoptotic morphology was further confirmed by Giemsa staining and transmission electron microscopy. Rates of apoptosis increased following PDT-HMME treatment in a time-dependent manner. Taken together, these results demonstrated that apoptosis plays a major role in PDT-HMME-induced reduction in the viability of CHMm cells.
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ABSTRACT: The effect of photodynamic therapy (PDT) on tumor growth as well as on tumor Å"il survival in vitro and in vivo was studied in the EMT-6 and RIF experimental mouse tumor systems. In vitro, RIF cells were more sensitive towards PDT than were EMT-6 cells when incubated with porphyrin (25 u,g/m\, dihema- toporphyrin ether) and subsequently given graded doses of light. In vivo, both tumor types responded to PDT (EMT-6, dihemato- porphyrin ether, 7.5 mg/kg; RIF, dihematoporphyrin ether, 10 mg/kg; both followed 24 hr later by 135 J of light at 630 nm/sq cm) with severe vascular disruption and subsequent disappear ance of tumor bulk. However, whereas the cure rate for EMT-6 tumors was 90%, it was 0% for RIF tumors. Raising the light dose to 200 J/sq cm resulted in 100% cures for EMT-6 tumors accompanied by damage to the surrounding tissues and 13% cures for RIF tumors. Tumor cell clonogenicity following PDT in vivo was assessed using the in vitro colony formation assay. In both tumors, it was found to be nearly unaffected by PDT if the tumor tissue was excised and explanted immediately following completion of treatment. This indicates that the effect of PDT on tumor cells directly was not sufficient to decrease tumor clono genicity even at doses which led to total macroscopic tumor destruction. Where the tumors remained in situ following PDT and explantation was delayed for varying lengths of time (1 to 24 hr), tumor cell death occurred rapidly and progressively, indicating that tumor cell damage was expressed only if the cells remained exposed to the in situ environment after treatment. The kinetics and extent of tumor cell death were very similar for both tumor types despite their difference in cure rates. The reduction in tumor clonogenicity at 4 hr post-PDT closely matched that of tumor deprived of oxygen for the same period of time, implying that one of the major factors contributing to tumor destruction may be damage of the tumor circulation and the consequences of treatment-induced changes in tumor phys iology.Cancer Research 03/1985; 45(2). · 8.65 Impact Factor
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ABSTRACT: More critical than for most other anatomy, intervention to cutaneous malignancy must not only be therapeutically successful but also achieve excellent cosmetic and functional outcome. As it can achieve those ends, PDT has moved to the forefront in the management of skin cancer. A number of well designed clinical trials and large patient series have reported outstanding outcomes for many histologies. This paper will review the rationale and outcomes of cutaneous PDT to malignancy using both topical and systemic photosensitizers. The benefits and drawbacks of cutaneous PDT are also examined.Photodiagnosis and Photodynamic Therapy - PHOTODIAGNOSIS PHOTODYN THER. 01/2006; 3(4):214-226.
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ABSTRACT: In order to evaluate the possibility of curative treatment of photodynamic therapy (PDT) in early stage central type lung cancer, 57 lesions in 48 patients were treated with PDT at Tokyo Medical College and 70 lesions at the Hayata Cancer Research Group of the Ministry of Health and Welfare of Japan. Apparent complete remission (CR) was obtained in 71.9% in the former and in 82% in the latter. There was a relationship between CR and the extent and growth type of the tumor. From the therapeutic results in these cases we estimated the indications of PDT in early stage lung cancer as follows. (1) The entire lesion should be visible endoscopically. (2) The tumor should be located at a site to which the laser beam can be delivered easily and sufficiently. (3) The lesion should be superficial and not more than 1.0 cm in diameter. (4) The histologic type should be squamous cell carcinoma. (5) There should be no lymph node involvement.Lung Cancer. 01/1993;