Figure 3. Overexpression of Bcl-2 results in increased STAT3^pTyr705.

A. Human chronic myeloid leukemia CEM cells overexpressing Bcl-2 were lysed and fractionated into mitochondria-enriched purified heavy membrane (HM) and cytosolic (S) fractions. The fractions were then probed for STAT3^pTyr705, total STAT3, Bcl-2^pSer70, total Bcl-2, Rac1, VDAC and Cu/Zn SOD. B. & C. Densitometry and statistical analyses of the changing ratios between STAT3^pTyr705 and total STAT3 as well as Bcl-2^pSer70 and total Bcl-2 are represented graphically. * denoting P-value < 0.05. D. & E. Lysates from control HeLa cells or cells transiently transfected with either the empty vector or Bcl-2 wild type (1μg of Bcl-2 plasmid was used in E) for 48 hrs were probed for STAT3^pTyr705, total STAT3, Bcl-2, Rac1, β-actin and STAT3^pSer727 E.. F. HeLa cells were either lysed into whole cell lysates (WCL) or fractionated into mitochondria-enriched purified heavy membrane (HM) and cytosolic (S) fractions. The fractions were then probed for STAT3^pTyr705 & STAT3^pSer727, total STAT3, total Bcl-2, Rac1, VDAC and Cu/Zn SOD.