ALA-induced photodynamic effect on vitality, apoptosis, and secretion of vascular endothelial growth factor (VEGF) by colon cancer cells in normoxic environment in vitro.

BACKGROUND: Cancer therapy is often based on combination of conventional methods of cancer treatment with immunotherapy. Photodynamic therapy (PDT) is one of the immunomodulating methods used in oncology. We examined how PDT influences the secretory activity of colon cancer cells in vitro, especially the secretion of vascular endothelial growth factor (VEGF) in aerobic conditions. METHODS: We used two cancer cell lines with different malignancy potentials: a metastatic SW620 line and a non-metastatic SW480 line. In the first stage of the experiment, we exposed each cell line to three different concentrations of photosensitizer's precursor: 5-aminolevulinic acid (ALA) and varying levels of light radiation, after which we assessed cell viability and apoptosis induction in these lines, using the MTT and LDH assays. Then, we determined the secretion of VEGF by these cells in aerobic conditions and under the ALA-PDT parameters at which cells presented the highest viability. RESULTS: Photodynamic treatment with ALA did not influence on VEGF secretion by the non-metastatic SW480 cells, but caused a decrease in VEGF secretion by the metastatic SW 620 cell line by 29% (p<0.05). SW 620 cell line secreted more actively VEGF than the SW480 cells, both before and after photo dynamic therapy (p<0.05). CONCLUSION: The outcome of this in vitro study presented a beneficial effect of ALA-PDT, resulting in a decrease of VEGF secretion in the more malignant SW620 cell lines. Further studies should be considered to confirm the clinical relevance of this finding.

Impact of low frequency pulsed magnetic fields on pain intensity, quality of life and sleep disturbances in patients with painful diabetic polyneuropathy.

AIM: The aim of this randomized, placebo-controlled, double-blind study was to assess whether a low frequency magnetic field can influence pain intensity, quality of life and sleep, and glycaemic control in patients with painful diabetic polyneuropathy. METHODS: Sixty-one patients were randomized into two groups: the study group comprised 32 patients exposed to a low frequency magnetic field, average pain duration 23 months; the control group included 29 patients who received sham exposure, average pain duration 28 months. Patients were exposed for three weeks, 20 min a day, five days a week. The magnetic field generator was a Viofor JPS device (Med & Life, Komorow, Poland). All subjects filled out the following questionnaires five times (at the beginning and after one, two, three and five weeks): SFMPQ-VAS (pain evaluation), EuroQol EQ-5D and MOS Sleep Scale. HbA(1c) was evaluated at baseline and after five weeks. RESULTS: Significant reductions in pain intensity were seen in both the study group (visual analogue scale [VAS] value of 73 mm at baseline versus 33 mm after three weeks) and controls (VAS 69 mm at baseline versus 41 mm after three weeks). The extent of pain reduction did not differ significantly between the groups at any time. Also, both groups had similar improvements in EuroQol, MOS and HbA(1c) values. CONCLUSION: Genuine magnetic field exposure has no advantage over sham exposure in reducing pain intensity, improving quality of life, and decreasing sleep disturbances and HbA(1c).