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Neutrophils infiltrate several types of cancer; however, whether their presence is associated with disease progression remains controversial. Here, we show that colon tumors overexpress neutrophil chemoattractants compared to healthy tissues, leading to their recruitment to the invasive margin and the central part of colon tumors. Of note, tumor-associated neutrophils expressing tumor necrosis factor α, which usually represents an antitumoral phenotype, were predominantly located in the invasive margin. Tumor-associated neutrophils from the invasive margin displayed an antitumoral phenotype with higher ICAM-1 and CD95 expression than neutrophils from healthy adjacent tissues. A higher neutrophil/lymphocyte ratio was found at later stages compared to the early phases of colon cancer. A neutrophil/lymphocyte ratio ≤3.5 predicted tumor samples had significantly more neutrophils at the invasive margin and the central part. Moreover, tumor-associated neutrophils at the invasive margin of early-stage tumors showed higher ICAM-1 and CD95 expression. Coculture of colon cancer cell lines with primary neutrophils induced ICAM-1 and CD95 expression, confirming our in situ findings. Thus, our data demonstrate that tumor-associated neutrophils with an antitumoral phenotype characterized by high ICAM-1 and CD95 expression infiltrate the invasive margin of early-stage colon tumors, suggesting that these cells can combat the disease at its early courses. The presence of tumor-associated neutrophils with antitumoral phenotype could help predict outcomes of patients with colon cancer.Neutrophils expressing TNFα, ICAM-1, and CD95 are located at the invasive margin of early-stage human colon cancer.

A new high-pressure flowmeter(HPFM)is described which is capable of rapid water-flow measurements. The HPFM permits dynamic determination of hydraulic conductance of roots, Kr, and can be used in teh laboratory or field. The base of a root is connected to the HPFM and water is perfused into the root system opposite to the normal direction of flow during trnaspiration. The perfusion pressure is changed at a constant rate of 3–7 kPa s−1 while measuring the flow into the root every 2–4 s. The slope of the plot of flow versus applied pressure is Kr. This paper describes the HPFM, presnents the theory of dynamic flow measurements, discusses sources of error, presnets evidence that dynamic measurements of Kr in Ficus maclellandi (and six other tropical species from Panama) yield the correct result, and demonstrates the use of the method under field conditions in Panama on Cecropia obtusifolia and Palicourea guianensis.