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: Abstract Purpose: The present study aims to investigate apoptosis of U937 cells induced by hematoporphyrin monomethyl ether (HMME)-mediated sonodynamic therapy (SDT). Materials: HMME concentration was kept constant at 10 μg/mL. Tumor cells suspended in serum-free RPM1640 were exposed to ultrasound at 1.1 MHz for up to 60 seconds with an intensity of 1 W/cm(2) in the presence and absence of HMME. The viability of cells was determined by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltertrazolium bromide tetrazolium (MTT) test. Apoptosis was analyzed using a flow cytometer with Annexin V-PE/7-ADD staining as well as fluorescence microscopy with 4'-6-diamidino-2-phenylindole (DAPI) staining. The DNA damage of U937 cells, intracellular reactive oxygen species (ROS), and mitochondria membrane potential (MMP) were also analyzed by a flow cytometer after exposures. Western blotting and reverse transcriptase-polymerase chain reaction were used to analyze the protein and mRNA expression level of caspase-3 and poly(ADP-ribose) polymerase (PARP). Results: Fluorescent imaging revealed that HMME mainly localized in the mitochondria. MTT assay showed 55.6% of cell survival at 4 hours post-SDT. Flow cytometric analysis displayed a significant increase in the early- and late-apoptotic cell populations (35.6%) of U937 cells by HMME-mediated SDT. Compared with the control, ultrasound-alone, and HMME-alone groups, the intracellular ROS and the MMP loss were greatly increased in the combined SDT group. Obvious nuclear condensation was also found with DAPI staining, and the DNA fragment increased to 33.9% at 2 hours post-SDT treatment. Immunofluorescent staining indicated obvious Bax translocation after SDT. Western blot showed visible enhancement of caspase-3 and PARP cleavage. In addition, caspase-3 and PARP mRNA expression of U937 cells increased remarkably after SDT treatment. Conclusions: The findings demonstrated that HMME-mediated sonodynamic action (HMME-SDT) significantly induced apoptosis of U937 cells, suggesting that HMME may be a good sonosensitizer, and HMME-SDT might be a potential therapeutic strategy for cancer treatment.Cancer Biotherapy & Radiopharmaceuticals 03/2013; · 1.44 Impact Factor
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ABSTRACT: We investigated the antitumor effect and mechanism of hematoporphyrin monomethyl ether-mediated photodynamic therapy (HMME-PDT) in sarcomas. Intracellular uptake of HMME by osteosarcoma cells (LM8 and K7) was time- and dose-dependent, while this was not observed for myoblast cells (C2C12) and fibroblast cells (NIH/3T3). HMME-PDT markedly inhibited the proliferation of sarcoma cell lines (LM8, MG63, Saos-2, SW1353, TC71, and RD) (P<0.05), and the killing effect was improved with increased HMME concentration and energy intensity. Flow cytometry analysis revealed that LM8, MG63, and Saos-2 cells underwent apoptosis after treatment with HMME-PDT. Additionally, apoptosis was induced after HMME-PDT in a three-dimensional culture of osteosarcoma cells. Hoechst 33342 staining confirmed apoptosis. Cell death caused by PDT was rescued by an irreversible inhibitor (Z-VAD-FMK) of caspase. However, cell viability was not markedly decreased compared with the HMME-PDT group. Expression levels of caspase-1, caspase-3, caspase-6, caspase-9, and poly (ADP-ribose) polymerase (PARP) proteins were markedly up-regulated in the treatment groups and increased with HMME concentration as determined by western blot analysis. In vivo, tumor volume markedly decreased at 7-16 days post-PDT. Hematoxylin and eosin staining revealed widespread necrotic and infiltrative inflammatory cells in the HMME-PDT group. Immunohistochemistry analysis also showed that caspase-1, caspase-3, caspase-6, caspase-9, and PARP proteins were significantly increased in the HMME-PDT group. These results indicate that HMME-PDT has a potent killing effect on osteosarcoma cells in vitro and significantly inhibits tumor growth in vivo, which is associated with the caspase-dependent pathway.PLoS ONE 01/2013; 8(10):e77727. · 3.73 Impact Factor
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ABSTRACT: Hematoporphyrin monomethyl ether (HMME) is a promising porphyrin-related photosensitize for photodynamic therapy (PDT). There still remains unknown changes regarding the mitochondrial in canine breast cancer cells treated with HMME-PDT. The aim of this study is to investigate the effect of HMME-PDT on structure and dysfunction of mitochondrial in cancer cells. The experimental approach included an initial study on the uptake of HMME using microscopic observation of the HMME-treated cells, optimization of the PDT-induced cell death by the MTT assay. These cells were then treated with HMME and a He-Ne laser at the wavelength of 632.8nm following our optimized condition. Examination of mitochondrial changes by observing the stained cells under light microscope, mitochjondrial membrane potential flow cytometry, measuring the Ca(2+), SOD/GSH activity, ATPase and MDA contents for the mitochondria functions. The kinetics of HMME uptake in CHMm cells was determined and its cytocolic instead of nuclear distribution was demonstrated. The dose of 16mM HMME-PDT combined with 2.8J/cm(2) laser irradiation was had the maximal impact on cell viability. This treatment resulted in structural changes in mitochondria that were accompanied with the loss of mitochjondrial membrane potential. As a result, HMME-PDT increased mitochondrial ROS, inhibited the enzymatic activities of mitochondrial SOD and GSH-Px, abolished mitochondrial ability in the uptake and release of calcium, and decreased mitochondrial ATPase activity. The combination of these abnormalities led to accumulation of ROS in mitochondrial to high levels, which in turn contributed to HMME-PDT-induced damages of mitochondrial structure and mitochondrial dysfunction.Photodiagnosis and photodynamic therapy 12/2013; 10(4):414-421.