BACKGROUND/AIM: Recurrence and metastasis of cancer caused by cancer stem cells (CSCs) is a challenge to overcome. Low level laser therapy is a new treatment strategy to suppress their invasiveness. We have assessed the inhibitory effects of 470 nm blue LED on the invasiveness of them to determine the molecular mechanisms of anti-invasiveness. MATERIALS AND METHODS: The effects of blue LEDs on their viability, proliferation and invasion were analyzed using MTT and transwell methods. In addition, the anti-invasiveness effect of blue LED on them was evaluated by zymography, semi-quantitative RT-PCR and western blot analysis. RESULTS: Irradiation with blue LED at 3 J/cm2 resulted in inhibition of their viability, proliferation and invasiveness. Their matrix metalloproteinase 2 (MMP-2) and MMP-9 activities were reduced by blue LED irradiation. Semi-quantitative RT-PCR also showed similar results. In addition, western blotting analyses showed that cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) synthesis were significantly inhibited by LED irradiation in CD133+ colorectal CSCs. CONCLUSION: Down-regulation of the COX-2/PGE2 signaling pathway by blue LED irradiation led to reduce expression of MMP-2 and MMP-9, inhibiting the invasiveness of CD133+ colorectal CSC.
AC133 Antigen/metabolism , Cyclooxygenase 2/metabolism , Dinoprostone/metabolism , Lasers, Semiconductor , Neoplastic Stem Cells/radiation effects , Signal Transduction/radiation effects , AC133 Antigen/genetics , Cell Proliferation/genetics , Cell Proliferation/radiation effects , Cell Survival/genetics , Cell Survival/radiation effects , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , Cyclooxygenase 2/genetics , Down-Regulation/radiation effects , Gene Expression Regulation, Neoplastic/radiation effects , Humans , Matrix Metalloproteinase 2/genetics , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/genetics , Matrix Metalloproteinase 9/metabolism , Neoplasm Invasiveness , Neoplastic Stem Cells/metabolism , Tumor Cells, Cultured
AIM: To investigate the bactericidal effects of calcium chelated N-acetylneuraminic acid-glycomacropeptide (CaG-NANA) against Helicobacter pylori (H. pylori). METHODS: For manufacture of CaG-NANA, calcium (Ca) was combined with glycomacropeptide (GMP) by chelating, and N-acetylneuraminic acid (NANA) was produced with Ca-GMP substrate by an enzymatic method. The final concentration of each component was 5% Ca, 7% NANA, 85% GMP, and 3% water. For in vitro study, various concentrations of CaG-NANA were investigated under the minimal inhibitory concentration (MIC). For in vivo study, CaG-NANA was administered orally for 3 wk after H. pylori infection. The levels of inflammatory cytokines in blood were analyzed by enzyme-linked immunosorbent assay and eradication of H. pylori was assessed by histological observation. RESULTS: The time-kill curves showed a persistent decrease in cell numbers, which depended on the dose of CaG-NANA, and MIC of CaG-NANA against H. pylori was 0.5% in vitro. Histopathologic observation revealed no obvious inflammation or pathologic changes in the gastric mucosa in the CaG-NANA treatment group in vivo. The colonization of H. pylori was reduced after CaG-NANA treatment. The levels of interleukin (IL)-6, IL-1ß, tumor necrosis factor-α, and IL-10 were also decreased by CaG-NANA. CONCLUSION: CaG-NANA demonstrates effective anti-bactericidal activity against H. pylori both in vitro and in vivo.
