Contributions
Abstract: PB1353
Type: Publication Only
Session title: Acute lymphoblastic leukemia - Biology & Translational Research
Background
Adhesion of acute leukemic cells (blasts) to the VE was significantly influenced by TNF and TGFβ1. TNF and TGFβ1 often accumulated in the blood of AL pts and correlated with the negative course of the AL. The pathogenetic role of cytokines in the spread of the AL has not been definitively established.
Aims
The aim of our investigation was to determine the role of TNF and TGFβ1 in changing the adhesive properties of the VE in 9 primary patients (pts) with AL (6 pts with ALL and 3 - AML).
Methods
Median of pts age was 68 years. The number of blasts in peripheral blood - 58,62±10,53%. We identified the attachment of labeled by 3H-thymidine cells lines K562, L1210 to the monolayer of human umbilical vein endothelial cells (HUVECs) in vitro after treated of plasma or 24 h-conditional mediums (CM) of blasts from blood pts, and to compare obtained data with concentration of TNF and TGFβ1 in the experimental samples. We also evaluated the effect of different doses of rhTGFβ1, rhTNF on the adhesive properties of HUVECs. Doses of rhTNF and rhTGFβ1 were selected according to the determined in plasma and CM of blasts from AL pts. The level of TNF and TGFβ1 was detected by bioassays using L929 and CCL64 in accordance. The attachment of K562, L1210 to HUVECs was estimated by the index of adhesion (IA). K562, L1210 were not activated before the investigation.
Results
TNF and TGFβ1 levels in plasma of AL pts were higher than in healthy donors (p<0,001). Plasma showed more strong influence on adhesion to HUVECs of K562 cells (IA=2,37±0,24), in comparison to L1210 (IA=1,28±0,8; p<0,05). Nevertheless TGFβ1 levels in CM of blasts AL pts was two-fold higher than in plasma of AL pts and inversely correlated with blasts number (r= - 0,40). Blasts of AL pts influenced on adhesive activity of HUVECs to K562 and L1210 (IA=1,99±0,38 and 1,92±0,24, respectively). CM of blasts secreted higher level of TGFβ1, than it was in plasma pts (p<0,05) We found that low concentrations (0,01 up to 2,40 ng/ml) of rhTGFβ1 stimulated significantly the adhesive properties of HUVECs. rhTGFβ1 in the ranges from 3,60 ng/ml up to 8,30 ng/ml inhibited adhesion of K562 cells (IA<1,00) but in the higher doses it stimulated adhesive properties of HUVECs again (IA>1,00). On the other hand we found that low concentrations of rhTNF (0,001 up to 0,01 ng/ml) correlated inversely with adhesion of K562 to HUVECs (IA from 4,33 to 1,0). rhTNF in the range 0,01 up to 0,1 ng/ml didn’t stimulate the attachment of K562 to HUVECs. Incubation of HUVECs with rhTNF in concentrations 0,8 up to 4,1 ng/ml resulted in significant increase of K562 adhesion (IA>1,0). After influence of rhTNF (0,001 up to 0,024 ng/ml) HUVECs demonstrated considerable adhesiveness to L1210 (IA from 1,42 to 3,02). rhTNF in range 0,03 up to 0,06 ng/ml diminished the attachment of L1210 (IA<1,0), but in the range (0,07 up to 2,03 ng/ml) it significantly induced the adhesion of L1210 again. Pretreatment of HUVECs by rhTNF more than 3,12 ng/ml didn’t induce any adhesion, perhaps via its cytotoxic influence on EC monolayer.
Conclusion
.Blasts were the powerful source of cytokines secretion that was able to modulated the adhesive properties of VE and may pathogenetically influence on spreading of AL.
TNF and TGFβ1 can affect different types of leukemia cells in different ways. On the other hand rhTNF and rhTGFβ1 in vitro changes the adhesive properties of HUVECs in a dose-dependent manner. Therefore, the adjustment of cytokine levels in the blood of AL pts may be an important step in the treatment of AL.
Keyword(s): Acute leukemia, Adhesion, Transforming growth factor-, Tumor necrosis factor (TNF)
Abstract: PB1353
Type: Publication Only
Session title: Acute lymphoblastic leukemia - Biology & Translational Research
Background
Adhesion of acute leukemic cells (blasts) to the VE was significantly influenced by TNF and TGFβ1. TNF and TGFβ1 often accumulated in the blood of AL pts and correlated with the negative course of the AL. The pathogenetic role of cytokines in the spread of the AL has not been definitively established.
Aims
The aim of our investigation was to determine the role of TNF and TGFβ1 in changing the adhesive properties of the VE in 9 primary patients (pts) with AL (6 pts with ALL and 3 - AML).
Methods
Median of pts age was 68 years. The number of blasts in peripheral blood - 58,62±10,53%. We identified the attachment of labeled by 3H-thymidine cells lines K562, L1210 to the monolayer of human umbilical vein endothelial cells (HUVECs) in vitro after treated of plasma or 24 h-conditional mediums (CM) of blasts from blood pts, and to compare obtained data with concentration of TNF and TGFβ1 in the experimental samples. We also evaluated the effect of different doses of rhTGFβ1, rhTNF on the adhesive properties of HUVECs. Doses of rhTNF and rhTGFβ1 were selected according to the determined in plasma and CM of blasts from AL pts. The level of TNF and TGFβ1 was detected by bioassays using L929 and CCL64 in accordance. The attachment of K562, L1210 to HUVECs was estimated by the index of adhesion (IA). K562, L1210 were not activated before the investigation.
Results
TNF and TGFβ1 levels in plasma of AL pts were higher than in healthy donors (p<0,001). Plasma showed more strong influence on adhesion to HUVECs of K562 cells (IA=2,37±0,24), in comparison to L1210 (IA=1,28±0,8; p<0,05). Nevertheless TGFβ1 levels in CM of blasts AL pts was two-fold higher than in plasma of AL pts and inversely correlated with blasts number (r= - 0,40). Blasts of AL pts influenced on adhesive activity of HUVECs to K562 and L1210 (IA=1,99±0,38 and 1,92±0,24, respectively). CM of blasts secreted higher level of TGFβ1, than it was in plasma pts (p<0,05) We found that low concentrations (0,01 up to 2,40 ng/ml) of rhTGFβ1 stimulated significantly the adhesive properties of HUVECs. rhTGFβ1 in the ranges from 3,60 ng/ml up to 8,30 ng/ml inhibited adhesion of K562 cells (IA<1,00) but in the higher doses it stimulated adhesive properties of HUVECs again (IA>1,00). On the other hand we found that low concentrations of rhTNF (0,001 up to 0,01 ng/ml) correlated inversely with adhesion of K562 to HUVECs (IA from 4,33 to 1,0). rhTNF in the range 0,01 up to 0,1 ng/ml didn’t stimulate the attachment of K562 to HUVECs. Incubation of HUVECs with rhTNF in concentrations 0,8 up to 4,1 ng/ml resulted in significant increase of K562 adhesion (IA>1,0). After influence of rhTNF (0,001 up to 0,024 ng/ml) HUVECs demonstrated considerable adhesiveness to L1210 (IA from 1,42 to 3,02). rhTNF in range 0,03 up to 0,06 ng/ml diminished the attachment of L1210 (IA<1,0), but in the range (0,07 up to 2,03 ng/ml) it significantly induced the adhesion of L1210 again. Pretreatment of HUVECs by rhTNF more than 3,12 ng/ml didn’t induce any adhesion, perhaps via its cytotoxic influence on EC monolayer.
Conclusion
.Blasts were the powerful source of cytokines secretion that was able to modulated the adhesive properties of VE and may pathogenetically influence on spreading of AL.
TNF and TGFβ1 can affect different types of leukemia cells in different ways. On the other hand rhTNF and rhTGFβ1 in vitro changes the adhesive properties of HUVECs in a dose-dependent manner. Therefore, the adjustment of cytokine levels in the blood of AL pts may be an important step in the treatment of AL.
Keyword(s): Acute leukemia, Adhesion, Transforming growth factor-, Tumor necrosis factor (TNF)