Histone deacetylase inhibitors, like suberoylanilide hydroxamic acid (SAHA), are potential
new drugs in oncologic treatment protocols. They can impact on proliferation and function
of T cells. We analysed the effects SAHA on T cells directly as well as on mesenchymal
stromal cells (MSC), which are known to modulate T cell responses. SAHA reduced the
suppressive effects of MSC on PBMC. In previous studies we found that tumor stromal
cells (TStrC) impair T cell function. As TStrC share several properties with MSC,
we hypothesized that in this particular setting SAHA may facilitate tumorimmunological
responses by downregulation of the immune suppression by TStrC. We isolated TStrC
from neuroblastoma patients and analysed the effect of SAHA on these TStrC including
cytokine patterns. Proliferation TStrC was only slightly affected at the pharmacologically
relevant concentration of 1,2µM. After treatment with SAHA, TStrC showed reduced inhibition
of the proliferation of PBMC and cytotoxicity of NK cells. These findings suggest,
that SAHA may modify the tumor microenvironment to allow for more efficient anti-tumor
immune responses.
