Causes and effects of heterogeneous perfusion in tumors.

摘要: A characteristic of solid tumors is their heterogeneous distribution blood flow, with significant hypoxia and acidity in low-flow regions. We review effects tumor perfusion are reviewed propose a conceptual model for its cause. Hypoxic-acidic regions resistant to chemo- radiotherapy may stimulate progression more metastatic phenotype. In normal tissues, induce angiogenesis, which expected improve perfusion. However, aggressive can have high local microvessel density simultaneously acidosis. possible explanation this apparent contradiction that the mechanisms regulating growth adaptation vascular networks impaired. According recent theory structural networks, four interrelated adaptive responses work as self-regulating system produce mature efficient tissues. It proposed result from perturbation system. Angiogenesis increase heterogeneity by increasing disparity between parallel low- high-resistance flow pathways. This provides basis future rational therapies. For example, it indicates selective destruction vasculature efficiency therapeutic efficacy.