Background: Long non-coding RNA growth arrest-specific 5 (GAS5) is deregulated in many cancers because of its role in cell growth arrest and apoptosis. Additionally, GAS5 interacts with glucocorticoid receptor, making it a potential pharmacotranscription marker of glucocorticoid (GC) therapy. In this study, we aimed at analysing GAS5 expression in the remission induction therapy phase of childhood acute lymphoblastic leukemia (ALL), in which GCs are mandatorily used, and to correlate it with therapy response.
Methods: GAS5 expression was measured in peripheral blood mononuclear cells taken from 29 childhood ALL patients at diagnosis, on day 15 and day 33 of remission induction therapy using RT-qPCR methodology.
Results: Our results have shown interindividual differences in GAS5 expression at all time points. For each ALL patient, GAS5 expression was higher on day 15 in comparison to its level at diagnosis (p<0.0005). On day 33, the level of GAS5 expression decreased in comparison with day 15 (p<0.0005), but it was still significantly higher than at diagnosis for the majority of patients (p=0.001). Patients whose number of blasts on day 8 was below 100 per μL of peripheral blood had a higher GAS5 expression at diagnosis (p=0.016), and lower ratio day 15/diagnosis (p=0.009).
Conclusions: Our results suggest that the expression level of GAS5 could be a potential marker of therapy response in remission induction therapy of childhood ALL.
Uvod: Ekspresija duge nekodirajuće RNK GAS5 je izmenjena u mnogim kancerima zbog njene uloge u apoptozi i inhibiciji rasta ćelije. GAS5 interaguje sa glukokortikoidnim receptorom, što je čini potencijalnim farmakotranskripcionim markerom značajnim za glukokortikoidnu terapiju. Naš cilj u ovoj studiji je bio da analiziramo ekspresiju GAS5 tokom indukcione terapije kod dečje akutne limfoblastne leukemije (ALL), u kojoj se koriste glukokortikoidni lekovi, i da te rezultate povežemo sa odgovorom na terapiju.
Metode: Nivo ekspresije GAS5 u mononuklearnim ćelijama periferne krvi izolovanih od 29 dece obolelih od ALL, određen je metodologijom RT-qPCR, i to u momentu dijagnoze, 15. i 33. dana indukcione terapije.
Rezultati: Naši rezultati su pokazali da postoje interindividualne razlike u ekspresiji GAS5 kod pacijenata, i to u svim analiziranim tačkama. Kod svakog ALL pacijenta GAS5 ekspresija je 15. dana bila viša u odnosu na ekspresiju u momentu dijagnoze (p < 0,0005). Nivo ekspresije GAS5 je 33. dana bio niži u poređenju sa 15. danom (p < 0,0005), ali je i dalje bio značajno viši u odnosu na momenat dijagnoze kod većine pacijenata (p = 0,001). Pacijenti čiji je broj blasta u perifernoj krvi 8. dana bio ispod 100 po mikrolitru periferne krvi, imali su viši nivo ekspresije GAS5 (p = 0,016) i niži odnos ekspresija merenih 15. dana i u momentu dijagnoze (p = 0,009).
Zaključak: Naši rezultati ukazuju da bi nivo ekspresije GAS5 mogao da bude marker terapijskog odgovora u indukcionoj terapiji kod dece obolele od ALL.
Keywords: GAS5; childhood ALL; glucocorticoid drugs; long non-coding RNA; pharmacotranscription.