Background and Objective: The severity of the spinal muscular atrophy phenotype is inversely associated with the expression levels of the SMN۲ gene; this correlation is not absolute, for this reason there is currently no effective treatment. The interference of other severity modifying factors, apart from SMN۲ gene expression has been suggested. Here we investigate the effects of valproic acid as a STAT۵ inducer not only on SMN۲ expression but on STAT۵A gene expression as well as on the rate of apoptosis.
Materials and Methods: Expression levels of the SMN۲ and STAT۵A genes were determined using Real-time PCR
while apoptotic rates were determined using flow cytometry in lymphocyte cell lines derived from three patients and two normal controls in response to valproic acid.
Results: STAT۵A gene induction, enhanced FL-SMN۲ expression and reduced apoptotic rate were seen in lymphocyte cell lines after valproic acid treatment (p<۰.۰۵, t-test).
Conclusion: Since STAT۵A gene induction was accompanied with SMN۲ transcriptional upregulation, these findings propose the involvement of STAT۵A gene both as a component of the STAT۵ pathway and as a target gene in drug responsiveness.