Fig. 4.

Enhancement of cell invasion by CD40-activated Mϕ-1 depends on tumor cell susceptibility to apoptosis. a MTT assays. KLE cells and EN-1078D cells were stimulated for 48 h in control media or with soluble factors from Mϕ1/isotype-CM or Mϕ1/αCD40-CM. Result shows viable cell number in percent of control mean. Different superscripts denote significant differences between groups; * p < 0.05, significantly decreased when compared with control mean. b Invasion assays. Result shows the number of invasive cells/field alone (basal) or after a 48 h co-culture period of KLE cells or EN-1078D cells with isotype- and CD40-activated Mϕ-1. Compared with KLE cells, EN-1078D cells are no responsive to the invasiveness induced by Mϕ-1/αCD40 macrophages. Different superscripts denote significant differences between groups; * p < 0.01, significantly increased when compared with the basal level of invasive cells. c Apoptosis assays. Hec1A, KLE, and EN-1078D cells were stimulated with CM from Mϕ1/isotype or Mϕ1/αCD40 macrophages for 48 h. Results from Western blot analysis show expression of cleaved caspase-3 (left panel). The protein β-actin was used as control to correct for loading, and blots are representative of three independent experiments. Relative level of cell apoptosis was expressed as cleaved caspase-3/β-actin ratio (right panel). Compared with KLE cells, EN-1078D cells are highly sensitive to the apoptosis induced by Mϕ1/isotype and even more by Mϕ1/αCD40 macrophage; * p < 0.01 denotes significant difference between groups