aluminum-tetrasulfophthalocyanine and Skin-Neoplasms

Photodynamic therapy is a medical treatment that uses an inactive dye/drug and lasers as a light source to activate the dye/drug to produce a toxic form of oxygen that destroys the cancer cells. This study aimed at investigating the cytotoxic effects of different concentrations of aluminum tetrasulfophthalocyanines in its inactive and active state (laser induced) on melanoma skin cancer cells, healthy normal skin fibroblast and keratinocyte cells. Experimentally, 3 × 10⁴ cells/ml were seeded in 24-well plates before treatment with different concentrations of aluminum tetrasulfophthalocyanines. After 2h, cells were irradiated with a light dose of 4.5 J/cm². Post-irradiated cells were incubated for 24h before cell viability was measured using the CellTiter-Blue Viability Assay. Results showed that aluminum tetrasulfophthalocyanines at high concentrations were cytotoxic to melanoma cells in the absence of laser activation. In the presence of laser activation of aluminum tetrasulfophthalocyanines at a concentration of 40 μg/ml decreased cell viability of melanoma cells to 45%, fibroblasts to 78% and keratinocytes to 73%. At this photosensitizing concentration of aluminum tetrasulfophthalocyanines the efficacy of the treatment light dose 4.5 J/cm² and the cell death mechanism induced by photoactivated aluminum tetrasulfophthalocyanines was evaluated. A light dose of 4.5 J/cm² was more efficient in killing a higher number of melanoma cells and a lower number of fibroblast and keratinocyte cells than the other light doses of 2.5 J/cm², 7.5 J/cm² and 10.5 J/cm². Apoptosis features such as blebbing, nucleus condensation, nucleus fragmentation and the formation of apoptotic bodies were seen in the photodynamic therapy treated melanoma skin cancer cells. This in vitro photodynamic therapy study concludes that using aluminum tetrasulfophthalocyanines at a photosensitizing concentration of 40 μg/ml in combination with a laser dose of 4.5 J/cm² was potentially lethal for melanoma skin cancer cells and less harmful for the normal healthy skin cells.

Topics: Cell Death; Cell Line, Tumor; Dose-Response Relationship, Drug; Fibroblasts; Fluorescent Dyes; Humans; Indoles; Keratinocytes; Melanoma; Organometallic Compounds; Photochemotherapy; Photosensitizing Agents; Skin Neoplasms

Photodynamic therapy (PDT) may trigger apoptosis or necrosis in cancer cells. Several steps in the induction and execution of apoptosis require high amounts of adenosine-5'-triphosphate (ATP). Because the mitochondrial membrane potential (delta psi) decreases early in apoptosis, we raised the question about the mechanisms of maintaining a sufficiently high ATP level. We therefore monitored delta psi and the intracellular ATP level of apoptotic human epidermoid carcinoma cells (A431) after photodynamic treatment with aluminum (III) phthalocyanine tetrasulfonate. A maximum of caspase-3-like activity and nuclear fragmentation was found at fluences of about 4 J cm(-2). Under these conditions apoptotic cells reduced delta psi rapidly, while the ATP level remained high for 4-6 h after treatment for cells supplied with glucose. To analyze the contribution of glycolysis to the energy supply during apoptosis, experiments were carried out with cells deprived of glucose. These cells showed a rapid drop of ATP content and neither caspase activation nor nuclear fragmentation could be detected. We conclude that the use of glucose as a source of ATP is obligatory for the execution of PDT-induced apoptosis.

Topics: Adenosine Triphosphate; Apoptosis; Caspase 3; Caspases; DNA Fragmentation; Glucose; Glycolysis; Humans; Indoles; Membrane Potentials; Mitochondria; Organometallic Compounds; Photochemotherapy; Radiation-Sensitizing Agents; Skin Neoplasms; Time Factors; Tumor Cells, Cultured

The purpose of this study was to examine the effects of photodynamic therapy utilizing aluminum phthalocyanine tetrasulfonate in vitro on several human malignant and normal cell types, with or without hyperthermia. Cells examined included normal skin fibroblasts, HT-1080 fibrosarcoma cells, SCC-25 (squamous cell carcinoma) and malignant melanoma cells. An argon-pumped continuous wave tunable dye laser at 675 nm was used as the light source, hyperthermia groups were heated to 42.5 degrees C, and radioisotope incorporation was used to measure DNA and protein synthesis as toxicity assays. Results showed an energy-dose, and A1PcS-concentration dependent toxicity in all cell lines examined, with moderate selectivity toward malignant cells. Hyperthermia alone was slightly toxic in melanomas and HT-1080 cell lines but had no effect in normal fibroblasts or SCC-25 cells. Hyperthermia synergistically potentiated the effects of PDT in all cell lines, and the combined modality was significantly more toxic in all malignant cell lines compared with normal cells. Thus, addition of hyperthermia to PDT protocols may enhance the efficacy of this treatment modality in vitro.

Topics: Carcinoma, Squamous Cell; Cell Line; Cell Survival; DNA Replication; DNA, Neoplasm; Fibroblasts; Fibrosarcoma; Humans; Hyperthermia, Induced; Indoles; Laser Therapy; Melanoma; Neoplasm Proteins; Organometallic Compounds; Photochemotherapy; Radiation-Sensitizing Agents; Skin; Skin Neoplasms; Tumor Cells, Cultured