Expression of integrins.

(A) Comparison of the relative amounts of α-integrins expressed in the SLGC lines indicated (data from proteome array). Based on the assumption that the antibodies spotted on the filters of the proteome array possessed similar KDs, the relative expression of the integrins was calculated. The sum of the signals of all integrins was arbitrary set at 100%. The bars indicate to what percentage the individual α-integrins contribute to this expression. (B) Similar analysis as in (A) comparing the relative expression of the integrins β1, β2, β3, β4, β5, and β6. (C) Western blot analysis using antibodies directed against the integrins αv, β1, β3, and β5. The loading controls Actin and GAPDH (glyceraldehyde-3-phosphate dehydrogenase) are shown below the corresponding blots. (D) Flow cytometry analysis experiment using early passages of SLGCs. The established non-SLGC cells lines U87 (glioblastoma) and CaCo2 (colon carcinoma) lack stemness. (E) Expression of mRNAs coding for the β-Integrins indicated. Total RNA was isolated from SLGC lines, subjected to reverse transcription and qRT- PCR analysis. Signal intensities were normalized against gapdh. (F) A similar experiment as in (E) investigating the effect of serum (10% fetal calf serum) on the expression of α- and β-integrin mRNAs, respectively. In order to highlight serum-mediated changes, the relative expression obtained with RNAs isolated from the corresponding serum-free cultures was arbitrary set at 1.- SC, derived from an orthotopic tumor. (TIF)