Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001511 (Adhesion)
 5,955 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Their glycolytic metabolism imposes an increased acid load upon tumour cells. The surplus protons are extruded by the Na+/H+ exchanger (NHE) which causes an extracellular acidification. It is not yet known by what mechanism extracellular pH (pHe) and NHE activity affect tumour cell migration and thus metastasis. We studied the impact of pHe and NHE activity on the motility of human melanoma (MV3) cells. Cells were seeded on/in collagen I matrices. Migration was monitored employing time lapse video microscopy and then quantified as the movement of the cell centre. Intracellular pH (pHi) was measured fluorometrically. Cell-matrix interactions were tested in cell adhesion assays and by the displacement of microbeads inside a collagen matrix. Migration depended on the integrin alpha2beta1. Cells reached their maximum motility at pHe approximately 7.0. They hardly migrated at pHe 6.6 or 7.5, when NHE was inhibited, or when NHE activity was stimulated by loading cells with propionic acid. These procedures also caused characteristic changes in cell morphology and pHi. The changes in pHi, however, did not account for the changes in morphology and migratory behaviour. Migration and morphology more likely correlate with the strength of cell-matrix interactions. Adhesion was the strongest at pHe 6.6. It weakened at basic pHe, upon NHE inhibition, or upon blockage of the integrin alpha2beta1. We propose that pHe and NHE activity affect migration of human melanoma cells by modulating cell-matrix interactions. Migration is hindered when the interaction is too strong (acidic pHe) or too weak (alkaline pHe or NHE inhibition).
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PMID:Migration of human melanoma cells depends on extracellular pH and Na+/H+ exchange. 1594 60

Adhesion and proliferation of cells are often suppressed in rigid hydrogels as gel stiffness induces mechanical stress to embedded cells. Herein, the composite hydrogel systems to facilitate high cellular activities are described, while maintaining relatively high gel stiffness. This unusual property is obtained by harmonizing gelatin-poly(ethylene glycol)-tyramine (GPT, semisynthetic polymer) and gelatin-hydroxyphenyl propionic acid conjugates (GH, natural polymer) into hydrogels. A minimum GH concentration of 50% is necessary for cells to be proliferative. GPT is utilized to improve biological stability (>1 week) and gelation time (<20 s) of the hydrogels. These results suggest that deficiency in cellular activity driven by gel stiffness could be overcome by finely tuning the material properties in the microenvironments.
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PMID:Enhanced Cellular Activity in Gelatin-Poly(Ethylene Glycol) Hydrogels without Compromising Gel Stiffness. 2666 97