Relationship of protoporphyrin IX synthesis to photodynamic effects by 5-aminolaevulinic acid and its esters on various cell lines derived from the skin

Tyrosinase-mediated melanogenesis in melanoma cells: Array comparative genome hybridization integrating proteomics and bioinformatics studies

We investigated the tyrosinase-associated melanogenesis in melanoma cells by using OMICS techniques. We characterized the chromosome copy numbers, including Chr 11q21 where the tyrosinase gene is located, from several melanoma cell lines (TXM13, G361, and SK-MEL-28) by using array CGH. We revealed that 11q21 is stable in TXM13 cells, which is directly related to a spontaneous high melanin pigment production. Meanwhile, significant loss of copy number of 11q21 was found in G361 and SK-MEL-28. We further profiled the proteome of TXM13 cells by LC-ESI-MSMS and detected more than 900 proteins, then predicted 11 hub proteins (YWHAZ; HSP90AA1; HSPA5; HSPA1L; HSPA9; HSP90B1; HSPA1A; HSPA8; FKSG30; ACTB; DKFZp686DQ972) by using an interactomic algorithm. YWHAZ (25% interaction in the network) is thought to be a most important protein as a linking factor between tyrosinase-triggered melanogenesis and melanoma growth. Bioinformatic tools were further applied for revealing various physiologic mechanisms and functional classification. The results revealed clues for the spontaneous pigmentation capability of TXM13 cells, contrary to G361 and SK-MEL-28 cells, which commonly have depigmentation properties during subculture. Our study comparatively conducted the genome-wide screening and proteomic profiling integrated interactomics prediction for TXM13 cells and suggests new insights for studying both melanogenesis and melanoma.

Hexyl aminolevulinate, 5-aminolevulinic acid nanoemulsion and methyl aminolevulinate in photodynamic therapy of non-aggressive basal cell carcinomas: A non-sponsored, randomized, prospective and double-blinded trial

BACKGROUND

In the photodynamic therapy (PDT) of non-aggressive basal cell carcinomas (BCCs), 5-aminolevulinic acid nanoemulsion (BF-200ALA) has shown non-inferior efficacy when compared with methyl aminolevulinate (MAL), a widely used photosensitizer. Hexyl aminolevulinate (HAL) is an interesting alternative photosensitizer. To our knowledge, this is the first study using HAL-PDT in the treatment of BCCs.

OBJECTIVES

To compare the histological clearance, tolerability (pain and post-treatment reaction) and cosmetic outcome of MAL, BF-200 ALA and low-concentration HAL in the PDT of non-aggressive BCCs.

METHODS

Ninety-eight histologically verified non-aggressive BCCs met the inclusion criteria, and 54 patients with 95 lesions completed the study. The lesions were randomized to receive LED-PDT in two repeated treatments with MAL, BF-200 ALA or HAL. Efficacy was assessed both clinically and confirmed histologically at three months by blinded observers. Furthermore, cosmetic outcome, pain, post-treatment reactions fluorescence and photobleaching were evaluated.

RESULTS

According to intention-to-treat analyses, the histologically confirmed lesion clearance was 93.8% (95% confidence interval [CI] = 79.9-98.3) for MAL, 90.9% (95% CI = 76.4-96.9) for BF-200 ALA and 87.9% (95% CI = 72.7-95.2) for HAL, with no differences between the arms (P = 0.84). There were no differences between the arms as regards pain, post-treatment reactions or cosmetic outcome.

CONCLUSIONS

Photodynamic therapy with low-concentration HAL and BF-200 ALA has a similar efficacy, tolerability and cosmetic outcome compared to MAL. HAL is an interesting new option in dermatological PDT, since good efficacy is achieved with a low concentration.

Nitric oxide regulates the expression of heme carrier protein-1 via hypoxia inducible factor-1α stabilization

Photodynamic therapy (PDT) is a cancer therapy that capitalizes on cancer-specific porphyrin accumulation. We have investigated this phenomenon to propose the following three conclusions: 1) the mechanism underlying this phenomenon is closely related to both nitric oxide (NO) and heme carrier protein-1 (HCP-1), 2) NO inactivates ferrochelatase, and thus, the intracellular porphyrin levels in the cells are increased by the administration of an NO donor after 5-aminolevulinic acid treatment, 3) HCP-1 transports not only heme but also other porphyrins. Since NO stabilizes hypoxia-inducible factor (HIF)-1α, resulting in the upregulation of heme biosynthesis, HCP-1 expression can be increased by HIF-1α stabilization. In this study, we determined whether NO regulates HCP-1 expression by stabilizing HIF-1α expression. For this purpose, rat gastric cancer cell line RGK36 was treated with L-arginine or N6-(1-iminoethyl)-L-lysine (L-NIL). L-arginine treatment increased the intracellular NO concentration, and both HCP-1 and HIF-1α expression, while L-NIL treatment decreased them. Cytotoxicity of PDT was enhanced by L-arginine, following intracellular hemato-porphyrin dihydrochloride (HpD) accumulation. Both Cytotoxicity of PDT and HpD accumulation were decreased by L-NIL. The HCP-1 and HIF-1α expression, intracellular HpD accumulation and PDT cytotoxicity were decreased by 2-methoxyestradiol, which is a HIF-1α inhibitor. Moreover, these phenomena were not increased by a combination of both L-arginine and 2-Me. Thus, HCP-1 can be a downstream target of HIF-1α. These effects were also induced in the human gastric cancer cell line MKN45. Taken together, we conclude that HCP-1 expression is regulated by NO via HIF-1α stabilization.

The influence of different illumination parameters on protoporphyrin IX induced cell death in squamous cell carcinoma cells

BACKGROUND

Topical photodynamic therapy (PDT) is a highly effective therapy especially for extended cancerized fields of the skin. Whenever extended fields are treated pain management is advisable. Light source mediated pain management can be performed by reducing fluence rates, as long as this does not compromise efficacy.

METHODS

Two squamous cell carcinoma cell lines (A431 and SCC-13) were subjected to in vitro PDT using two different ALA concentrations and synthesis intervals and protoporphyrin IX (PpIX) synthesis was assessed. Two total light doses (6 J/cm² and 37 J/cm²) were applied at three different fluence rates and cell viability was measured using the MTS-test.

RESULTS

Both cell lines synthetized PpIX at different kinetics. A431 cells produced a maximum 28.6 nmol/l PpIX, while SCC-13 reached only a production of 8.7 nmol/l. Illumination reduced cell viability depending on PpIX content and light dose. When a lower light dose (6 J/cm²) was applied, only the combination with the highest PpIX content was effective in A431 cells and no effect could be detected in SCC-13 cells. With a light dose of 37 J/cm², lower PpIX amounts became effective in A431 and cell death could be induced in SCC-13 cells. Light fluence rate had no differential effect in this setup.

CONCLUSIONS

In both, A431 and SCC-13 cells, total light dose is a key factor for photodynamic efficacy. Additionally, our results hint towards a threshold concentration of PpIX upon which a drastic loss of viability occurs. Light fluence rate in the analyzed range is not a limiting factor of photodynamic cytotoxicity. This may allow for the clinical implementation of low fluence rate protocols for pain management without compromising efficacy.

Inhibitory effect of aloe emodin mediated photodynamic therapy on human oral mucosa carcinoma in vitro and in vivo

We report a study on inhibition of human oral squamous cell carcinoma in vitro and in vivo, using novel photosensitizer (PS) aloe emodin (AE) mediated photodynamic therapy (PDT). Distinct morphology changes of oral mucosa carcinoma KB cells were observed under an optical microscope and cell migrations were inhibited owing to AE-PDT. The cell proliferation was blocked in G1 phase and the apoptosis increase were both caused by massive reactive oxygen species (ROS) generated from photoactivated AE. The upregulation of Caspase-3 and Bax protein levels and downregulation of Bcl-2 protein levels were observed after AE-PDT. The survival time of tumor mouse was prolonged without side effects ascribed to AE-PDT and its inhibitory effect on mice transplantation tumors was significant. It is indicated that AE mediated PDT is an innovative way to oral cancer treatment with the dominances of effectivity, minimal invasion, tissue integrity retention and none side effects on main organs.

Aminolevulinic Acid-Mediated Photodynamic Therapy Causes Cell Death in MG-63 Human Osteosarcoma Cells

OBJECTIVE

The aim of this study was to test the efficacy of aminolevulinic acid-mediated photodynamic therapy (PDT) against the human osteosarcoma cell line MG-63.

BACKGROUND DATA

Osteosarcoma is the most common type of primary malignant bone tumor diagnosed in the United States among adolescents and children. Treatments for osteosarcoma often result in diminished limb use or amputation. Because ALA-mediated PDT exhibits dual specificity in the context of tumor killing, this therapy could represent a less invasive, but effective, treatment for this disease.

MATERIALS AND METHODS

To assess ALA dark toxicity in MG-63 cells, cells were incubated with varying concentrations of ALA, and cell viability was determined by crystal violet assay. Protoporphyrin IX (PpIX) accumulation was assessed subsequent to ALA incubation at various concentrations using spectrofluorometry. Cell death subsequent to ALA-PDT was determined by illuminating cells at a wavelength of 635 nm at various light intensities subsequent to ALA incubation. Cell viability was assessed using the MTT assay.

RESULTS

ALA dark toxicity was observed only at the highest concentrations of 2, 5, and 10 mM. Maximal PpIX concentration was observed at 0.5 and 1 mM ALA, subsequent to a 24-h incubation. Maximal cell death with minimal light toxicity was observed at 0.5 and 1 mM ALA after illumination with 0.6 and 3 J/cm(2) light.

CONCLUSIONS

Collectively, our data indicate that ALA-PDT can result in the death of MG-64 human osteosarcoma cells in vitro.

Daylight photodynamic therapy with 1.5% 3-butenyl 5-aminolevulinate gel as a convenient, effective and safe therapy in acne treatment: A double-blind randomized controlled trial

While daylight photodynamic therapy (PDT) is a simpler and more tolerable treatment procedure for both clinicians and patients, it has never been applied for acne treatment. In this study, we evaluated efficacy, safety and histological changes of facial acne after application of the novel variant of 5-aminolevulinate (ALA)-ester, 1.5% 3-butenyl ALA-bu gel, using daylight only as the potential visible light source. Forty-six acne patients were randomly assigned to either ALA-bu or vehicle application group in a double-blind fashion. Both groups applied the allocated gel to facial acne lesions every other day for 12 weeks. At the final 12 week, both inflammatory and non-inflammatory acne lesions had decreased significantly by 58.0% and 34.1% in the ALA-bu group, respectively. Only a few patients expressed mild adverse effects. In the histopathological analysis, attenuated inflammatory cell infiltrations were observed and immunostaining intensities for interleukin-8, interleukin-1β, matrix metalloproteinase-9 and phosphorylated nuclear factor-κB were reduced concomitantly. Changes of their mRNA expression demonstrated comparable patterns. In conclusion, this ambulatory PDT was effective, very well tolerated and convenient for treating inflammatory acne lesions. Experimental results correlated well with clinical results. This novel regimen would provide a viable option for acne therapy.

Cell death pathways in photodynamic therapy of cancer

Photodynamic therapy (PDT) is an emerging cancer therapy that uses the combination of non-toxic dyes or photosensitizers (PS) and harmless visible light to produce reactive oxygen species and destroy tumors. The PS can be localized in various organelles such as mitochondria, lysosomes, endoplasmic reticulum, Golgi apparatus and plasma membranes and this sub-cellular location governs much of the signaling that occurs after PDT. There is an acute stress response that leads to changes in calcium and lipid metabolism and causes the production of cytokines and stress response mediators. Enzymes (particularly protein kinases) are activated and transcription factors are expressed. Many of the cellular responses center on mitochondria and frequently lead to induction of apoptosis by the mitochondrial pathway involving caspase activation and release of cytochrome c. Certain specific proteins (such as Bcl-2) are damaged by PDT-induced oxidation thereby increasing apoptosis, and a build-up of oxidized proteins leads to an ER-stress response that may be increased by proteasome inhibition. Autophagy plays a role in either inhibiting or enhancing cell death after PDT.

Efficacy of photodynamic diagnosis-guided Mohs micrographic surgery in primary squamous cell carcinoma

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) usually has ill-defined margins because of its irregular invasive patterns.

OBJECTIVE

To evaluate the surgical efficacy of photodynamic diagnosis (PDD) in primary cSCC treated using Mohs micrographic surgery (MMS).

METHODS & MATERIALS

We examined 67 cases of biopsy-proven primary facial cSCC treated with MMS. The 67 SCC were divided into the two groups depending on PDD application: PDD group (n = 38, 56.7%) and non-PDD group (n = 29, 43.3%). We analyzed the differences in surgical features between the PDD and non-PDD groups.

RESULTS

The PDD group required fewer Mohs stages (1.37 vs 1.83, p = .02) and smaller surgical margins (8.03 vs 11.24 mm, p = .03). PDD showed additional benefits in terms of surgical margin and Mohs stage, especially in low-risk SCC, including thin (≤4 mm), small (≤20 mm), well-differentiated, and nonulcerative tumors (p < .05) but did not show beneficial effects in high-risk SCC (p > .05) during MMS.

CONCLUSION

PDD can increase surgical efficacy of primary cSCC during MMS. These benefits are more pronounced in low-risk SCC. We recommend PDD as a simple and useful technique for delineating the margins of low-risk SCC before MMS.

The enhanced anti-cancer effect of hexenyl ester of 5-aminolaevulinic acid photodynamic therapy in adriamycin-resistant compared to non-resistant breast cancer cells

BACKGROUND AND OBJECTIVE

5-Aminolaevulinic acid (ALA) and its derivatives act as precursors of the photosensitizer protoporphyrin IX (PpIX). In this study, we compared cytotoxic effects of photodynamic therapy (PDT) with the hexenyl ester of ALA (ALA-hx) between MCF-7 human breast cancer cells and adriamycin-resistant MCF-7 (MCF-7/ADR) cells.

MATERIALS AND METHODS

Cell viability and apoptosis were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylte-trazolium bromide (MTT), flow cytometry assays. Chick chorioallantoic membrane (CAM) assays were applied to assess in vivo effect of ALA-hx PDT. Molecular analyses using Western blots and minimal reporter constructs containing the antioxidant response element (ARE) region were performed to reveal mechanistic basis for the differential PDT sensitivity of MCF-7 and MCF-7/ADR cells.

RESULTS

In MCF-7/ADR cells, PDT with ALA-hx more efficiently produced reactive oxygen species (ROS) and suppressed cell viability compared to MCF-7 cells. Cell death induced by ALA-hx PDT in MCF-7/ADR cells was mainly due to apoptosis. CAM assays confirmed that the apoptotic activity of PDT in MCF-7/ADR cells was significantly higher than that in control MCF-7 cells. We also found that MCF-7/ADR cells produced lower levels of glutathione (GSH), a major antioxidant, than control MCF-7 cells. Expression of Nrf2-dependent anti-oxidant genes including γ-glutamylcysteine ligase, heme oxygenase-1, and quinone oxidoreductase were down-regulated in MCF-7/ADR cells, and Nrf2 overexpression partially decreased the susceptibility of ALA-hx PDT in MCF-7/ADR cells. Moreover, PpIX synthesis and expression levels of protoporphyrinogen oxidase (PPO) and coproporphyrinogen oxidase (CPO) were much higher in MCF-7/ADR cells than MCF-7 cells.

CONCLUSIONS

ALA-hx PDT more potently produced intracellular ROS in MCF-7/ADR cells, which might be due to down-regulation of Nrf2-mediated anti-oxidant gene transcription and up-regulation of PpIX synthesis via the induction of CPO and PPO. These findings suggest that ALA-hx PDT may be usable as a therapeutic alternative for adriamycin-resistant breast cancer.

The microfluidic system for studies of carcinoma and normal cells interactions after photodynamic therapy (PDT) procedures

This study reports on the use of a microsystem for evaluation of photodynamic therapy (PDT) procedures on the "mixed" (carcinoma-normal) cultures. Balb/3T3 (normal mouse embryo) and A549 (human lung carcinoma) cells were tested in separated and "mixed" cultures. Interactions and migration of cells cultured together were observed. The PDT procedures were examined in the hybrid (PDMS/glass) microsystem which contains cell culture microchambers integrated with network of microchannels. We investigated that the number of dead cells after PDT procedures is dependent on the kind of cell culture. Moreover, the influence of the carcinoma cells on the viability of normal cells in the "mixed" culture was observed.

δ-Aminolevulinic acid and its methyl ester induce the formation of Protoporphyrin IX in cultured sensory neurones

Application of δ-aminolevulinic acid (ALA) or its methyl ester (MAL) onto cutaneous tumours increases intracellular Protoporphyrin IX (PpIX), serving as photosensitizer in photodynamic therapy (PDT). While PDT is highly effective as treatment of neoplastic skin lesions, it may induce severe pain in some patients. Here, we investigated ALA and MAL uptake and PpIX formation in sensory neurones as potential contributor to the pain. PpIX formation was induced in cultured sensory neurones from rat dorsal root ganglion by incubation with ALA or MAL. Using inhibitors of GABA transporters (GAT), a pharmacological profile of ALA and MAL uptake was assessed. GAT mRNA expression in the cultures was determined by RT-PCR. Cultured sensory neurones synthesised Protoporphyrin IX (PpIX) from extracellularly administered ALA and MAL. PpIX formation was dose- and time-dependent with considerably different kinetics for both compounds. While partial inhibition occurred using L-arginine, PpIX formation from both ALA and MAL could be fully blocked by the GABA-Transporter (GAT)-2/3 inhibitor (S)-SNAP 5114 with similar K (i) (ALA: 195 ± 6 μM; MAL: 129 ± 13 μM). GAT-1 and GAT-3 could be detected in sensory neurons using RT-PCR on mRNA level and using [³H]-GABA uptake on protein level. Cultured sensory neurones take up ALA and MAL and synthesize PpIX from both, enabling a direct impact of photodynamic therapy on cutaneous free nerve endings. The pharmacological profile of ALA and MAL uptake in our test system was very similar and suggests uptake via GABA and amino acid transporters.

Aminolevulinic Acid (ALA) as a Prodrug in Photodynamic Therapy of Cancer

Aminolevulinic acid (ALA) is an endogenous metabolite normally formed in the mitochondria from succinyl-CoA and glycine. Conjugation of eight ALA molecules yields protoporphyrin IX (PpIX) and finally leads to formation of heme. Conversion of PpIX to its downstream substrates requires the activity of a rate-limiting enzyme ferrochelatase. When ALA is administered externally the abundantly produced PpIX cannot be quickly converted to its final product - heme by ferrochelatase and therefore accumulates within cells. Since PpIX is a potent photosensitizer this metabolic pathway can be exploited in photodynamic therapy (PDT). This is an already approved therapeutic strategy making ALA one of the most successful prodrugs used in cancer treatment.

Anticancer effect of photodynamic therapy with hexenyl ester of 5-aminolevulinic acid in oral squamous cell carcinoma

BACKGROUND

Five-aminolaevulinic acid (ALA) and its derivatives act as precursors of the photosensitizer protoporphyrin IX (PpIX). In this study, the effect of photodynamic therapy (PDT) with hexenyl ester of ALA (ALA-hx) was examined in a human oral squamous cell carcinoma, YD10B cells.

METHODS

PpIX accumulation and mRNA expression of coproporphyrinogen oxidase (CPO) by ALA and ALA-hx was examined. Cell viability was examined by MTT assay and the molecular mechanism was investigated.

RESULTS

The PpIX synthesis and mRNA expression of CPO was much higher in the cells treated with ALA-hx than ALA. At the concentration that PDT with ALA did not affect cell growth, ALA-hx PDT effectively produced reactive oxygen species (ROS) and suppressed cell growth. Growth inhibition by ALA-hx PDT was due to mitochondrial-dependent apoptosis.

CONCLUSION

Our results suggest that ALA-hx PDT effectively induced apoptosis of YD-10B cells and can be considered as a therapeutic alternative for oral cancer.

Evaluation of photodynamic therapy (PDT) procedures using microfluidic system

A hybrid PDMS/glass microfluidic system for evaluation of the efficiency of photodynamic therapy is presented. 5-aminolevulinic acid (ALA) was used as a precursor of photosensitizer. The geometry of the microdevice presented in this paper enables to test different concentrations of the photosensitizer in a single assay. The viability of the A549 cells was determined 24 h after PDT procedure (irradiation with light which induced a photosensitizer accumulated in carcinoma cells, λ=625 nm). The presented results confirmed the possibility to perform the photodynamic therapy process in vitro in microscale and the possibility to assess its effectiveness. Moreover, because two identical microstructures on a single chip were performed, the microchip can be used for examination simultaneously various cell lines (carcinoma and normal) or various photosensitizers.

Comparison of pharmacokinetics, intracellular localizations and sonodynamic efficacy of endogenous and exogenous protoporphyrin IX in sarcoma 180 cells

PURPOSE

The aim of the present study was to investigate the differences in pharmacokinetics, sub-cellular localizations and sonodynamic efficacy between endogenous and exogenous protoporphyrin IX (endo-PpIX and exo-PpIX) in sarcoma 180 (S180) cells.

MATERIALS AND METHODS

The 5-aminolevulinic acid (ALA)-derived endo-PpIX and exo-PpIX pharmacokinetic profiles were determined by the fluorescence intensity of cell extracts with a spectrophotometer based on a standard curve. The changes in their sub-cellular localization patterns over a prolonged incubation time were evaluated by laser scanning confocal microscopy. The cytotoxic effects of 5-ALA-mediated sonodynamic therapy (ALA-SDT) and exogenous PpIX-mediated sonodynamic therapy (PpIX-SDT) were also evaluated by the MTT assay.

RESULTS

The exo-PpIX showed dose-dependent pharmacokinetics in which a plateau of intra- and extracellular content was observed 45min after administration. However, the amount of ALA-derived endogenous intracellular PpIX, as well as extracellular PpIX in the same samples, showed linear accumulation with incubation time, which was independent of ALA concentration. Fluorescent imaging revealed that the exo-PpIX mainly accumulated at the plasma membrane in the early stage, whereas the ALA-derived PpIX initially localized in the mitochondria. Cells displayed sonodynamic damage by the synthesized endo-PpIX after addition of 1mM ALA for 12h, but the cytotoxicity induced by the equivalent amount of exo-PpIX was much more significant with increasing ultrasound intensities.

CONCLUSIONS

Our findings suggest that endo- and exo-PpIX in S180 cells differ not only in pharmacokinetics but also in sub-cellular localizations, which may affect their sonodynamic efficacy and mechanisms of inducing cell death.