[Human multiple myeloma cell line RPMI8226 activates brain derived neurotrophic factor autocrine loop of co-cultured endothelial cells].
OBJECTIVE
To study the influence of multiple myeloma cells on normal endothelial cells in co-culture system.


METHODS
Human multiple myeloma cell line RPMI8226 was co-cultured with human umbilical vein endothelial cells (HUVECs). HUVECs cultured alone were used as control. The expression of brain derived neurotrophic factor (BDNF) and its specific acceptor TrkB mRNA and protein in HUVECs were determined by RT-PCR and Western blot, respectively, BDNF levels in culture supernatant by enzyme-linked immunosorbent assay (ELISA). After transferring the co-culture, the effects RPMI8226 on HUVECs angiogenesis were studied by modified transwell migration assay and net-like formation assay.


RESULTS
The median BDNF concentration in culture supernatant was increased in co-cultured HUVECs compared with that in HUVECs cultured alone [(31.6 +/- 7.2) ng/ml vs (12.4 +/- 5.1) ng/ml, P < 0.05]. The expression of BDNF transcript demonstrated by RT-PCR did the same in the two culture systems (1.7 fold increase, P < 0.05). TrkB mRNA was hardly detected in culture of HUVECs alone but was increased in co-cultured HUVECs (4.4- fold increase, P < 0.05). The BDNF and TrkB protein expressions determined by Western blot were similar to that of their mRNAs. On the other hand, the RPMI8226 activated HUVECs showed enhanced migration and net-like formation, being increased by 99% and 72% , respectively. Addition of anti-human BDNF antibody to the culture medium partly reduced these effects.


CONCLUSIONS
Multiple myeloma cells activated BDNF/TrkB autocrine loops in co-cultured endothelial cells and resulted in endothelial self-activating angiogenesis.
Wang
Ya-Dan
YD
Institution of Hematology and Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
Hu
Yu
Y
Sun
Chun-Yan
CY
He
Wen-Juan
WJ
Zhang
Xiao-Ping
XP
D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism*; D002450:Cell Communication; D045744:Cell Line, Tumor; D018920:Coculture Techniques; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D009101:Multiple Myeloma / Q000473:pathology*; D018919:Neovascularization, Physiologic; D012333:RNA, Messenger / Q000378:metabolism; D020813:Receptor, trkB / Q000378:metabolism*
D019208:Brain-Derived Neurotrophic Factor; D012333:RNA, Messenger; D020813:Receptor, trkB