Deficiency of Taspase1 Results in Increased Anoikis and Decreased Anchorage-independent Growth of SK-MEL-2 Melanoma and U251 Glioblastoma Cells. A, Human cancer cell lines with control- or Taspase1-knockdown were stained with annexin V and analyzed by FACS. B, Human cancer cell lines with control- or Taspase1-knockdown were cultured in PolyHEMA pre-treated 6-well plates for 3 days, stained with annexin V, and analyzed by FACS. C, SK-MEL-2, U251, or HT-29 cells with control- or Taspase1-knockdown were plated on soft agar. Positive clones (>100 μm) were scored 2-3 weeks after the initial plating of 105 cells. Scale bar equals 500 μm. Annexin V stains positive for apoptotic cells. Data presented in A, B, and C are mean ± SD duplicates of three independent experiments.