Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029463 (osteosarcoma)
 16,637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have clarified that photodynamic therapy (PDT) with acridine orange (AO) exerts a rapid and strong cytocidal effect on mouse osteosarcomas, both in vitro and in vivo, and have sought to apply this therapy to patients with musculoskeletal sarcomas, in order to reduce the surgical margin and obtain better limb function after tumor resection in limb salvage surgery. Some clinical studies have reported that the local recurrence rate after limb salvage surgery in patients receiving PDT therapy was less than 10% and that the limb functions recovered to nearly normal in these patients. For these basic and clinical studies, we used a blue light beam filtered from a xenon lamp for the AO excitation, because of its maximal absorption. However, the relationship between the cytocidal effect of PDT and the wavelength or illuminance (lux) of the excitation light in AO-PDT is unknown. Therefore, we investigated the cytocidal effects of AO-PDT on mouse osteosarcoma cells using lights of various illuminances and wavelengths from a xenon lamp. Our results revealed that, while the blue and green filtered lights exerted cytocidal effects depending on their illuminance, orange light exerted no such effect. Blue light showed the strongest cytocidal effect under constant illuminance. However, unfiltered light with 10 times the illuminance of blue light yielded a much stronger cytocidal effect, which was deduced not to be due to DNA injury by ultra-violet light or heat generation by ultra-red light, since a xenon lamp emits little of either light. Based on these results, we conclude that, for effective AO-PDT in clinical practice, strong unfiltered light from a xenon lamp is more effective and feasible than weak filtered blue light.
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PMID:Unfiltered xenon light is useful for photodynamic therapy with acridine orange. 1630 87

A photodynamic therapy technique with acridine orange (AO-PDT) was experimentally developed and applied clinically to musculoskeletal sarcoma patients to reduce the surgical margin and obtain good limb function. Furthermore, various modalities to enhance and strengthen the cytocidal effect of AO-PDT were investigated. A recent report revealed that the use of stronger unfiltered xenon light in AO-PDT enhanced the cytocidal efficacy of this treatment modality. Therefore, in this study, we investigated whether the use of a flash wave light (FWL) from a xenon lamp, as compared to that of the conventional continuous wave light (CWL), might enhance the cytocidal effect of AO-PDT, using the mouse osteosarcoma cell line, LM8. For an equal energy dose (79.6 joules/cm2), AO-PDT using FWL (10 minutes excitation) was found to exert a significantly stronger cytocidal effect than that using CWL (18 seconds excitation). For the same excitation time (10 minutes' excitation), the use of FWL (79.6 jouleslcm2) was associated with a significantly stronger cytocidal effect of AO-PDT than that of CWL (3,820 joules/cm2). These results reveal that the use of FWL entails the need for a lower excitation energy and shorter excitation time than that of CWL for the cytocidal effect of AO-PDT to be observed against the osteosarcoma cells. In addition, FWL also has the advantage of generating low heat and of having the ability to homogenously illuminate a wider area. We therefore concluded that FWL is more useful for AO-PDT than CWL in terms of saving on the excitation time and of obtaining good efficacy of destruction of the residual tumor in the treatment of musculoskeletal sarcomas.
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PMID:Flash wave light strongly enhanced the cytocidal effect of photodynamic therapy with acridine orange on a mouse osteosarcoma cell line. 1797 79

In a recent study, we demonstrated that a high-power flash wave light (FWL) from a xenon lamp exerted a stronger cytocidal effect against a mouse osteosarcoma cell line than continuous wave light (CWL) in photodynamic therapy with acridine orange (AO-PDT). Based on our in vitro results, we investigated the in vivo anti-tumor activity of AO-PDT using flash wave light from a xenon lamp in a mouse osteosarcoma model. Mouse osteosarcoma cells (LM8) were injected into the subcutaneous tissue of the back of C3H mice, and tumors that grew to approximately 3 mm in diameter were treated by AO-PDT using FWL. AO was administered by intravenous injection and 2 h later the entire body of the mouse was illuminated with FWL from a xenon lamp. Significant growth inhibition of the tumor xenografts was observed as compared with that in the control group, suggesting that AO-PDT with FWL may be useful in the treatment of osteosarcoma. An immunohistochemical study of the tumors treated by AO-PDT showed that the underlying mechanism of the tumor growth inhibition involved both apoptosis and necrosis. In conclusion, it appears that following the intravenous administration of AO, AO-PDT in combination with FWL exerts strong anti-tumor activity. Inhibitory effects against growth of the primary tumor in human patients with osteosarcoma as well as other musculoskeletal sarcomas were also observed.
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PMID:In vivo anti-tumor activity of photodynamic therapy with intravenous administration of acridine orange, followed by illumination with high-power flash wave light in a mouse osteosarcoma model. 2296 58

Osteosarcoma (OS) is the most common primary malignant bone tumor in children and adolescents. It is characterized by highly complex karyotypes with structural and numerical chromosomal alterations. The observed OS-specific characteristics in localization and frequencies of chromosomal breakages strongly implicate a specific set of responsible driver genes or a specific mechanism of fragility induction. In this study, a comprehensive assessment of somatic copy number alterations (SCNAs) was performed in 160 OS samples using whole-genome CytoScan High Density arrays (Affymetrix, Santa Clara, CA). Genes or regions frequently targeted by SCNAs were identified. Breakage analysis revealed OS specific unstable regions in which well-known OS tumor suppressor genes, including TP53, RB1, WWOX, DLG2 and LSAMP are located. Certain genomic features, such as transposable elements and non-B DNA-forming motifs were found to be significantly enriched in the vicinity of chromosomal breakage sites. A complex breakage pattern-chromothripsis-has been suggested as a widespread phenomenon in OS. It was further demonstrated that hyperploidy and in particular chromothripsis were strongly correlated with OS patient clinical outcome. The revealed OS-specific fragility pattern provides novel clues for understanding the biology of OS.
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PMID:Genome-wide analysis of somatic copy number alterations and chromosomal breakages in osteosarcoma. 2849 5

A novel singlet-oxygen sensitive drug delivery nanocarrier able to release its cargo after exposure to visible (Vis) light from a common lamp is presented. This nanodevice is based on mesoporous silica nanoparticles (MSN) decorated with porphyrin-caps grafted via reactive oxygen species (ROS)-cleavable linkages. In the presence of Vis light porphyrin-nanocaps produce singlet oxygen molecules that break the sensitive-linker, which triggers pore uncapping and therefore allows the release of the entrapped cargo (topotecan, TOP). This new system takes advantage of the non-toxicity and greater penetration capacity of Vis radiation and a double antitumor effect due to the drug release and the ROS production. In vitro tests with HOS osteosarcoma cancer cells reveal that TOP is able to be released in a controlled fashion inside the tumor cells. This research work constitutes a proof of concept that opens up promising expectations in the search for new alternatives for the treatment of cancer.
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PMID:A novel visible light responsive nanosystem for cancer treatment. 2901 95