RESUMO
The main constituent of green tea, (-)-Epigallocatechin-3-O-gallate (EGCG), is known to have cancer-specific chemopreventive effects. In the present work, we investigated how EGCG suppresses cell adhesion by comparing the adhesion of human pancreatic cancer cells (AsPC-1 and BxPC-3) and their counterpart, normal human embryonic pancreas-derived cells (1C3D3), in catechin-containing media using organosilane monolayer templates (OMTs). The purpose of this work is (1) to evaluate the quantitativeness in the measurement of cell adhesion with the OMT and (2) to show how green-tea catechins suppress cell adhesion in a cancer-specific manner. For the first purpose, the adhesion of cancer and normal cells was compared using the OMT. The cell adhesion in different type of catechins such as EGCG, (-)-Epicatechin-3-O-gallate (ECG) and (-)-Epicatechin (EC) was also evaluated. The measurements revealed that the anti-adhesion effect of green-tea catechins is cancer-specific, and the order is EGCGâ«ECG>EC. The results agree well with the data reported to date, showing the quantitativeness of the new method. For the second purpose, the contact area of cells on the OMT was measured by reflection interference contrast microscopy. The cell-OMT contact area of cancer cells decreases with increasing EGCG concentration, whereas that of normal cells remains constant. The results reveal a twofold action of EGCG on cancer cell adhesion-suppressing cell attachment to a candidate adhesion site and decreasing the contact area of the cells-and validates the use of OMT as a tool for screening cancer cell adhesion.
Assuntos
Catequina/análogos & derivados , Adesão Celular/efeitos dos fármacos , Pâncreas/efeitos dos fármacos , Neoplasias Pancreáticas/tratamento farmacológico , Catequina/administração & dosagem , Catequina/química , Linhagem Celular Tumoral , Humanos , Neoplasias Pancreáticas/patologia , Chá/químicaRESUMO
Ischaemia-reperfusion (I/R) is involved in the development of various organ diseases. There has been increasing evidence that cutaneous I/R injury is associated with the pathogenesis of pressure ulcers (PUs), especially at the early stage presenting as non-blanchable erythema. However, there is no evidence-based treatment for early-stage PUs. Our objective was to assess the effects of topical steroid on the development of PUs after cutaneous I/R injury in mice. Cutaneous I/R was performed by trapping the dorsal skin between two magnetic plates for 12 h, followed by plate removal. Topical application of betamethasone butyrate propionate (BBP) in I/R areas significantly increased the size of PUs after I/R. The number of thromboses was increased, and CD31(+) vessels were decreased in the I/R area treated with topical BBP. The number of oxidative stress-associated DNA-damaged cells and apoptotic cells in the I/R area was increased by topical BBP treatment. In addition, the mRNA level of NADPH oxidase 4 (Nox4), the essential enzyme that produces reactive oxygen species, was significantly increased and that of NF-E2-related factor 2 (Nrf2), a transcription factor that regulates the expression of antioxidant proteins, was inhibited in the I/R area treated by BBP. The number of CD68(+) macrophages and the level of transforming growth factor-beta in lesional skin were also decreased by BBP. These results suggest that a topical steroid might accelerate the formation of PUs induced by cutaneous I/R injury by aggravating oxidative stress-induced tissue damage. Topical steroids might not be recommended for the treatment of acute-phase decubitus ulcers.