aluminum-phthalocyanine-disulfonate and Carcinoma--Squamous-Cell

Treatment modalities, such as hyperthermia and photodynamic therapy (PDT) have been used in the treatment of a variety of head and neck squamous cell carcinoma (HNSCC), either alone or as an adjuvant therapy. Macrophages loaded with gold nanoshells, which convert near-infrared light to heat, can be used as transport vectors for photothermal hyperthermia of tumors. The purpose of this study was to investigate the effects of combined macrophage mediated photothermal therapy (PTT) and PDT on HNSCC cells.. Gold nanoshell loaded rat macrophages either alone or combined with human FaDu squamous cells in hybrid monolayers were subjected to PTT, PDT, or a simultaneous combination of the two light treatments. Therapies were given concurrently employing two laser light sources of λ = 670 nm (PDT) and λ = 810 nm (PTT), respectively.. Significant uptake of gold nanospheres (AuNS) by rat alveolar macrophages was observed thus providing the rationale for their use as delivery vectors. Viability of the AuNS-loaded Ma was reduced to 35 and 12% of control values at an irradiance of 14 or 28 W/cm(2) administered over a 5 minute period respectively. No significant cytotoxicity was observed for empty Ma for similar PTT exposure. AlPcS2a mediated PDT at a fluence level of 0.25 J/cm(2) and PTT at 14 W/cm(2) irradiance had little effect on cell viability for the FaDu/Ma (ratio 2:1) hybrid monolayers. In contrast, combined treatment reduced the cell viability to less than 40% at these same laser power settings.. The results of this study provide proof of concept for the use of macrophages as a delivery vector of AuNS for photothermal enhancement of the effects of PDT on squamous cell carcinoma. A significant synergy was demonstrated with combined PDT and PTT compared to each modality applied separately.

Topics: Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Line, Tumor; Combined Modality Therapy; Drug Delivery Systems; Gold; Head and Neck Neoplasms; Humans; Hyperthermia, Induced; Indoles; Macrophages; Nanoshells; Organometallic Compounds; Photochemotherapy; Photosensitizing Agents; Rats; Squamous Cell Carcinoma of Head and Neck

The use of photodynamic therapy (PDT) for the treatment of skin and oral cancer has been the subject of several clinical studies but there has been little scientific evaluation of its mechanism of action. Evidence to date suggests that whilst epithelial cell death may be secondary to vascular damage, direct cell killing may occur and may involve an apoptosis-like mechanism. To investigate the mechanism of epithelial cell death following PDT, two cell lines, human epidermal keratinocytes (UP) and oral squamous cell carcinoma-derived cells (H376) were subjected to PDT with aluminium disulphonated phthalocyanine (AlS2Pc) as the photosensitizer and red laser light at 675 nm. Control groups received red laser light, photosensitizer or neither. The effects of PDT were assessed using an MTS cell-proliferation assay, which showed a significant reduction in viability (p < 0.01) for PDT-treated cells compared to controls. For morphological analysis, cells were stained with haemotoxylin and eosin and the numbers showing typical apoptotic features counted. The treated cultures showed significantly increased numbers of apoptotic cells. Moreover, the H376 control cultures showed a baseline level of apoptosis of approx. 15%. Apoptosis was confirmed by ultrastructural analysis and by in situ end-labeling of DNA fragments. The results show that PDT using AlS2Pc as a photosensitizer promotes apoptotic cell death in UP and H376 cells in vitro and suggest that direct killing of epithelial cells may contribute to tumour necrosis in vivo.

Topics: Aluminum; Apoptosis; Carcinoma, Squamous Cell; Cell Count; Cell Division; Cell Line; Cell Survival; Coloring Agents; DNA Fragmentation; Eosine Yellowish-(YS); Epidermis; Epithelial Cells; Fluorescent Dyes; Hematoxylin; Humans; Indoles; Keratinocytes; Laser Therapy; Mouth Neoplasms; Necrosis; Organometallic Compounds; Photochemotherapy; Photosensitizing Agents; Tumor Cells, Cultured

Photosensitizer-induced fluorescence is studied as a technique for the detection of cancer. Therefore we investigated the ability of a photosensitizer, aluminum phthalocyanine disulfonate (AIPcS2), to localize in tumor tissue. In vivo endoscopic fluorescence imaging, fluorescence microscopy, conventional spectrofluorometry and high performance liquid chromatograpy combined with diode laser-induced fluorescence (HPLC-Dio-LIF) were used. Squamous cell carcinomas were induced with 4-nitro-quinoline-1-oxide (4NQO) in the mucosa of the palate of the rat. In vivo fluorescence images, taken after injection of 1.5 mumol/kg AIPcS2 intravenously, showed that 4NQO-treated palates had higher fluorescence signals than normal palates. Areas displaying locally high amounts of AIPcS2 fluorescence (hot spots) were present only in 4NQO-treated rats 2-8 h but had disappeared 24 h after injection. However, HPLC-Dio-LIF showed that the relative AIPcS2 content was highest at 24/48 h in biopsies taken in the areas of the hot spots. Fluorescence microscopy revealed that AIPcS2 was present only between 2 and 8 h in the epithelial layer, while in biopsies the connective tissue contained large quantities of AIPcS2 at 24/48 h. In vivo fluorescence imaging appears to show mainly fluorescence from the epithelial layer and the ex vivo analytical techniques mainly show the connective tissue fluorescence. Care should be taken when interpreting data using one technique only.

Topics: Animals; Carcinoma, Squamous Cell; Chromatography, High Pressure Liquid; Indoles; Male; Microscopy, Fluorescence; Mouth Neoplasms; Organometallic Compounds; Photosensitizing Agents; Rats; Rats, Wistar; Spectrometry, Fluorescence

Sulphonated phthalocyanines are studied as photosensitizers for photodynamic therapy of cancer. Their strong fluorescence and tumour-localising properties make them also potentially useful for detection of cancer by fluorescence. For this purpose, we have studied the fluorescence kinetics and localisation of aluminum phthalocyanine disulphonate (AlPcS2) in 4-nitroquinoline 1-oxide (4NQO)-induced dysplasia and invasive cancer of the oral mucosa of the hard palate in Wistar albino rats. Twenty-two rats were divided into six groups. Five groups were subjected to a 4NQO application period of 8, 12, 16, 20 or 26 weeks and one was a control group. The dysplasia varied from slight to severe and was correlated with the duration of the application period. All animals received a dose of 1 micromol/kg AlPcS2 i.v. Fluorescence images were recorded via a specially designed 'palatoscope' with excitation at 460 +/- 20 nm for autofluorescence, 610 +/- 15 nm for AlPcS2 fluorescence and detection of emission at 675 +/- 15 nm. After subtraction of the two images the specific AlPcS2 fluorescence remained. AlPcS2-mediated fluorescence increased significantly when the severity of dysplasia increased (P<0.04). Also the phenomenon of strong fluorescent spots on the fluorescence images was observed. This always occurred within the first 10 h after injection of AlPcS2. Histological analysis showed a local alteration to a mucosa in 67% of these spots, which was either invasive cancer (29%) or inflammation (38%). These results suggest two different mechanisms of AlPcS2 uptake in tissue, one associated with the presence of generalised dysplasia and another associated with local changes of the epithelial/connective tissue, which is not necessarily specific for tumours.

Topics: 4-Nitroquinoline-1-oxide; Animals; Carcinoma, Squamous Cell; Fluorescence; Fluorescent Dyes; Indoles; Organometallic Compounds; Palatal Neoplasms; Photochemotherapy; Radiation-Sensitizing Agents; Rats; Rats, Wistar

Effective antitumor photodynamic therapy (PDT) may be related to damage of vasculature within the tumor. The purpose of this study was to determine if tumor cells secrete factors that stimulate proliferation of human umbilical vein endothelial cells (HUVEC) and result in enhanced sensitivity of HUVEC to aluminum-sulfonated phthalocyanine (AlSPc)-PDT. Three human tumor cell lines--pharyngeal squamous carcinoma, colonic carcinoma, and mammary carcinoma--were used in this study. Co-culture of HUVEC and either squamous carcinoma or colonic carcinoma, but not mammary carcinoma, significantly increased HUVEC proliferation and AlSPc-PDT mediated cell damage. In addition, supernatant from squamous carcinoma and colonic carcinoma cultures also stimulated HUVEC proliferation and sensitivity to AlSPc-PDT. Both supernatant and cell lysate from squamous carcinoma cells contained angiogenic factors consistent with basic and acidic fibroblast growth factors, as evidenced by Western blot analysis and BALB/c 3T3 fibroblast cell proliferation assays. Collectively, these results suggest that selected tumor cell lines produce angiogenic factors that induce HUVEC proliferation and subsequently enhance sensitivity to AlSPc-PDT.

Topics: 3T3 Cells; Aluminum; Animals; Blotting, Western; Carcinoma; Carcinoma, Squamous Cell; Cell Division; Cell Line; Cells, Cultured; Endothelium, Vascular; Fibroblast Growth Factor 1; Fibroblast Growth Factor 2; Humans; Indoles; Lasers; Mice; Mice, Inbred BALB C; Neovascularization, Pathologic; Organometallic Compounds; Photochemotherapy; Radiation-Sensitizing Agents; Tumor Cells, Cultured; Umbilical Veins

In order to investigate the mechanism of action of photodynamic therapy (PDT) with sulfonated aluminum phthalocyanine (AlSPc) in squamous cell carcinoma, animal experiments were performed in induced carcinomas of the mucosa of the hamster's cheek pouch and skin of the laboratory mouse. Histological examinations revealed signs of massive interstitial bleeding, indicating a vascular response to PDT with AlSPc. It was also possible to induce similar change adjacent to newly formed vessels at the margin of an inflammatory reaction in the cheek pouch of five hamsters in the absence of tumor cells. Implanted human squamous cell carcinoma cells in athymic nude mice showed that carcinoma cells removed immediately following PDT remained viable, while tumors left in situ became necrotic. These results suggest that the primary effect of PDT with AlSPc in vivo is not the malignant cell itself, but the vascular stroma of the tumor or in the immediate vicinity of the latter.

Topics: Animals; Carcinoma, Squamous Cell; Cheek; Cricetinae; Indoles; Male; Mesocricetus; Mice; Mice, Nude; Mouth Mucosa; Mouth Neoplasms; Neoplasm Transplantation; Organometallic Compounds; Photochemotherapy; Radiation-Sensitizing Agents; Skin Neoplasms