Transforming growth factor beta and other angiogenic factors in hematologic malignancies of childhood

ABSTRACT

Angiogenesis, a process of new blood vessels formation from an existing vasculature, has been blamed for growth, dissimination and metastasis of solid tumors. Little is known about angiogenesis and angiogenesis- related molecules in hematologic malignancies. Transforming growth factor-beta [TGF- beta] and platelet-derived growth factor-C [PDGF-C] are considered as indirect angiogenic factors in tumorigenesis. Gangliosides and hyaluronan are components of cell membrane that modulate cell membrane signal transduction of multiple growth factors. The aim of this study is to assess serum levels of TGF- beta, PDGF-C, Gangliosides, and hyaluronan in children with newly diagnosed malignancies including 15 cases with acute lymphoblastic leukemia [ALL], 15 cases with non Hodgkin lymphoma [NHL], and 10 cases with neuroblastoma. Ten matchable apparently healthy children were included as controls. Results of the study showed that cases as a whole had significantly higher levels of TGF-beta, PDGF-C, gangliosides and hyaluronan than controls. Furthermore cases with hematologic malignancies as well as those with neuroblastoma had significantly higher levels of the studied parameters than controls. On comparing the different groups of cases with each other, it was found that cases with ALL and NHL had significantly higher level of TGF-beta than cases with neuroblastoma whereas the latter group had significantly higher level of gangliosides than ALL and NHL groups and higher level of hyaluronan than ALL group. Cases of NHL and neuroblastoma with advanced disease had significantly higher levels of the studied parameters than the rest of cases. In conclusion the angiogeneic factors TGF-beta, PDGF-C, gangliosides, and hyaluronan are raised in children with ALL and NHL as well as in those with neuroblastoma. Their levels are significantly higher in severer cases with advanced stages of malignancy. The estimation of their levels therefore not only points to the severity but also help to predict progress in these cases