Active oxygen intermediates in the degradation of hematoporphyrin derivative in tumor cells subjected to photodynamic therapy

Novel sulfonamide porphyrin TBPoS-2OH used in photodynamic therapy for malignant melanoma

The application of photodynamic therapy (PDT) for the treatment of skin diseases has been receiving much attention. Here, we examined the anti-tumor effect of a novel porphyrin-based photosensitizer TBPoS-2OH in the malignant melanoma A375 and B16 cells. TBPoS-2OH has obvious cell photo-cytotoxicity, but it has low cell dark-cytotoxicity. Further research showed that TBPoS-2OH is enriched in lysosomes after being taken up by cells. Subsequently, the apoptotic rates were significantly increased in TBPoS-2OH-treated A375 and B16 cells. The specific mechanism may be that after receiving light stimulation, TBPoS-2OH could effectively increase the level of intracellular reactive oxygen species (ROS), thereby activating mitochondrial apoptosis pathway-related proteins in A375 and B16 cells. We found an increase in the content of cytochrome C in the cytoplasm, and the levels of related proteins, such as cleaved caspase-3, cleaved caspase-9, and cleaved PARP1, were significantly increased in TBPoS-2OH-treated cells. These results indicated that the new compound TBPoS-2OH could be developed and become an alternative drug for the treatment of melanoma. Some reference ideas for the development of new photosensitizers are also provided.

High-effective reactive oxygen species inducer based on Mn-tetraphenylporphyrin loaded PLGA nanoparticles in binary catalyst therapy

The mechanisms of binary catalyst therapy (BCT) and photodynamic therapy (PDT) are based on the formation of reactive oxygen species (ROS). This ROS formation results from specific chemical reactions. In BCT, light exposure does not necessarily initiate ROS formation and BCT application is not limited to regions of tissues that are accessible to illumination like photodynamic therapy (PDT). The principle of BCT is electron transition, resulting in the interaction of a transition metal complex (catalyst) and substrate molecule. Mn^III- tetraphenylporphyrin chloride (MnClTPP) in combination with an ascorbic acid (AA) has been proposed as an appropriate candidate for cancer treatment regarding the active agents in BCT. The goal of this study was to determine whether MnClTPP in combination with AA would be a promising agent for BCT. The problem of used MnClTPP's, low solubility in water, was solved by MnClTPP loading into PLGA matrix. H₂O₂ produced during AA decomposition oxidized MnClTPP to high-reactive oxo-Mn^V species. MnClTPP in presence AA leads to the production of excessive ROS levels in vitro. ROS are mainly substrates of catalase and superoxide dismutase (H₂O₂ and O₂^●-). SOD1 and catalase were identified as the key players of the MnClTPP ROS-induced cell defense system. The cytotoxicity of MnClTPP-loaded nanoparticles (NPs) was greatly increased in the presence of specific catalase inhibitor (3-amino-1,2,4-triazole (3AT)) and superoxide dismutase 1 (SOD1) inhibitor (diethyldithiocarbamate (DDC)). Cell death resulted from the combined activation of caspase-dependent (caspase 3/9 system) and independent pathways, namely the AIF translocation to nuclei. Preliminary acute toxicity and in vivo anticancer studies have been revealed the safe and potent anticancer effect of PLGA-entrapped MnClTPP in combination with AA. The findings indicate that MnClTPP-loaded PLGA NPs are promising agents for BCT.

Monitoring of hydrogen peroxide production under photodynamic treatment using protein sensor HyPer

An interest to H₂O₂ accumulation under photodynamic treatment can be explained by its participation in intracellular signal cascades. It is important not only to detect H₂O₂ generation, but also to trace the dynamics of its intracellular content. In the present study the dynamics of cellular H₂O₂ content under photodynamic treatment was analyzed using genetically encoded reversible H₂O₂-sensitive sensor HyPer. Real-time detecting of H₂O₂ production after photodynamic treatment was performed using the protein sensor and individual features of action of different photosensitizers were revealed. Photodynamic treatment with a number of chlorin and phthalocyanine photosensitizers was found to induce secondary production of H₂O₂ in the cells. Three types of dynamic responses were registered: monotonous increase of H₂O₂ level during the entire observation time in the presence of Fotoditazin and Holosens; transient short-term accumulation in the presence of Radachlorin and Phthalosens; and relatively low-level stable increase in the presence of Photosens. The listed photosensitizers differ significantly in intracellular localization and physicochemical properties, which can determine the differences in the response of H₂O₂ after the photodynamic treatment. In general, it has been shown that the rapid transient H₂O₂ response is typical for hydrophobic compounds localized in membrane cell structures, whereas in the presence of more hydrophilic dyes a prolonged monotonous H₂O₂ accumulation occurs.

Influence of Photodynamic Therapy on Apoptosis and Invasion of Human Cholangiocarcinoma QBC939 Cell Line

OBJECTIVE

To investigate the effect of photodynamic therapy (PDT) mediated by hematoporphyrin derivative (HPD) on apoptosis and invasion of cholangiocarcinoma QBC939 cell lines.

METHODS

In vitro cultured cholangiocarcinoma QBC939 cell line was exposed to 2, 4, 6, 8, 10, 12, and 14 μg/ml HPD with 5, 10, and 15 J/cm2 light intensity, respectively. The optical density at 450 nm of the QBC939 cells was measured by CCK8 assay and its growth inhibition ratio was calculated. Flow cytometry and transwell migration assay were applied to detect cell apoptosis and invasion respectively. RT-PCR and immunocytochemistry analyses were used to detect expressions of vascular endothelial growth factor-C (VEGF-C), cyclooxygenase-2 (COX-2), and proliferating cell nuclear antigen (PCNA). Enzyme-linked immunosorbent assay (ELISA) was carried out to examine the secretion of VEGF-C and COX-2 in QBC939 cells.

RESULTS

Exposure to HPD-PDT can significantly suppress the growth of QBC939 cells (all P<0.05). HPD-PDT can promote apoptosis of QBC939 cells at the early stage. When the concentration of HPD was 2 μg/ml and light irradiation was 5 J/cm2, HPD-PDT had no obvious inhibitory effect on QBC939 cell growth, but can obviously inhibit cell invasion, and significant difference was observed between the HPD-PDT and control groups (P<0.01). The HPD-PDT can reduce the mRNA and protein expressions of VEGF-C, COX-2, and PCNA, and decrease the secretion of VEGF-C and COX-2 in QBC939 cells.

CONCLUSION

PDT could promote apoptosis and inhibit growth and invasion of cholangiocarcinoma cells QBC939 in vitro.

Forty-six cases of nasopharyngeal carcinoma treated with 50 Gy radiotherapy plus hematoporphyrin derivative: 20 years of follow-up and outcomes from the Sun Yat-sen University Cancer Center

BACKGROUND

With the improved overall survival (OS) of nasopharyngeal carcinoma (NPC) patients, the importance of quality of life (QoL) is increasingly being recognized. For some radiosensitive NPC patients, whether low-dose radiotherapy can improve the QoL without affecting clinical efficacy is unknown. This study aimed to assess the survival rates and QoL of NPC patients treated with 50 Gy radiotherapy plus hematoporphyrin derivative (HPD).

METHODS

Forty-six newly diagnosed NPC patients treated with 50 Gy radiotherapy plus HPD between June 1988 and July 1992 were analyzed. All patients were restaged according to the 7th edition of the American Joint Committee on Cancer staging system. The radiotherapy plan was designed on the basis of pretreatment computed tomography. The OS, local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and disease-free survival (DFS) rates were estimated using the Kaplan-Meier method. QoL was assessed using the Late Radiation Morbidity Scoring Criteria of the Radiation Therapy Oncology Group.

RESULTS

The 5-year OS, LRFS, DMFS, and DFS rates were 74.3%, 72.6%, 82.1%, and 61.2%, respectively. The corresponding 10-year rates were 38.4%, 62.9%, 78.5%, and 49.8%, respectively, and the 20-year rates were 27.7%, 51.4%, 78.5%, and 40.7%, respectively. None of the patients developed severe radiation-related complications, such as radiation-induced temporal lobe necrosis, hearing loss, trismus, and dysphagia.

CONCLUSION

Some NPC patients were sensitive to 50 Gy radiotherapy plus HPD, and this sensitivity was characterized by long-term survival without significant late treatment morbidities.

Evaluation of fractionated and repeated sonodynamic therapy by using dual frequency for murine model of breast adenocarcinoma

Background

Sonodynamic therapy (SDT) is a new approach for cancer treatment. Repair by reoxygenation induces cell damage in all treatment which uses photo- and sonosensitizers. In this study, the in vivo antitumor effect of dual-frequency sonication is investigated at low-level intensity and hematoporphyrin (Hp). It is used for the treatment of spontaneous breast adenocarcinoma of Balb/c mice with a variety of dose repetition and fractionation regimes.

Methods

Eighty tumor-bearing mice were divided into eight groups, the control group (A); the sham group (B); the injection of Hp alone group (C); 30-min dual-frequency sonication with Hp injection in one repetition at the first day group (D); two repetitions at the first and sixth days group (E); three repetitions at the first, sixth, and twelfth days group (F); four repetitions at the first, sixth, twelfth, and eighteenth days (30 min/repetition) group (G); and the fractional treatment group treated by dual-frequency sonication and Hp injection at the first, third, sixth, and ninth days (7.5 min/fraction) (H). For each group, the tumor growth delay was calculated during 30 days after treatment. These tumors were studied histopathologically.

Results

The results show that the treatment with ultrasound dose repetition in two, three, and four times (E, F, and G groups) were effective in delaying tumor growth compared with one-time sonication (D group) (p < 0.05). Also, the ultrasound dose fractionation is more effective in decreasing the tumor growth rate compared with the ultrasound dose repetition in four repeats and in one repeat from the 12th to the 30th day (p < 0.05). Histopathological studies indicated that the mitotic activity of tumor cells was reduced following treatment with four fraction and four repetition protocols.

Conclusion

The ultrasound dose fractionation and repetition technique with dual-frequency sonication can have a useful therapeutic effect in sonodynamic therapy with the possibility of use in future clinical applications.

Photodynamic therapy promotes apoptosis of cholangiocarcinoma QBC939 cells

AIM: To investigate the effect of photodynamic therapy on cholangiocarcinoma QBC939 cell apoptosis.

METHODS: Cultured cholangiocarcinoma QBC939 cells were given different concentrations of hematoporphyrin derivatives and different light intensity. The relative growth inhibition rate of QBC939 cells was detected by the CCK8 method. Flow cytometry assays were applied to determine the rate of QBC939 cell apoptosis. RT-PCR was used to detect transcriptional changes of proliferating cell nuclear antigen (PCNA). Immunocytochemistry was used to measure the changes in protein expression of PCNA.

RESULTS: PDT inhibited QBC939 cell growth in vitro, and significant different A values between the PDT group and control group was observed (0.403 ± 0.027 vs 2.028 ± 0.013, P < 0.05). When the concentration of HPD was 8 mg/L and the light irradiation was 5 J/cm², the relative growth inhibition rate of QBC939 cells was 80%. The increase in drug concentration or light dose did not significantly increase the growth inhibition rate. Flow cytometry assays showed that PDT could promote early apoptosis of QBC939 cells (74.6% ± 1.5%). PDT could reduce the transcriptional changes of PCNA (0.68 ± 0.06) and down-regulated the expression of PCNA protein in QBC939 cell nuclei (4.5% ± 1.4%).

CONCLUSION: PDT could inhibit QBC939 cell growth and promote early apoptosis of QBC939 cells. PDT induces QBC939 cell growth inhibition possibly by inhibiting PCNA gene and protein expression and promoting early apoptosis.

Hematoporphyrin derivative-mediated photodynamic therapy inhibits tumor growth in human cholangiocarcinoma in vitro and in vivo

AIM

To investigate the effects of hematoporphyrin derivative-mediated photodynamic therapy (HPD-PDT) on cell growth in human cholangiocarcinoma in vitro and in vivo, as well as the underlying mechanisms of these effects.

METHODS

3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate growth status of human cholangiocarcinoma cell line (QBC939). Hoechst 33258 staining and flow cytometry assays were applied to determine cell apoptosis. Western blotting analysis was performed to detect the release of cytochrome c in QBC939 cells, and caspases enzymatic assay was used to investigate the activation of caspase-3, -8, and -9. Further, tumor growth after subcutaneous implantation of QBC939 cells in nude mice was monitored.

RESULTS

HPD-PDT inhibits QBC939 cell growth via cell apoptosis in vitro, and initiates cell mitochondria apoptosis pathway by the release of cytochrome c and the activation of caspase-9 and -3. Moreover, HPD-PDT also inhibits subcutaneous tumor growth of QBC939 cells and reduces tumor cell mitosis in nude mice.

CONCLUSION

HPD-PDT inhibits tumor growth of human cholangiocarcinoma, suggesting that HPD-PDT is useful in cholangiocarcinoma therapy.