Differential expression ß2 and ß4 isoforms of retinoic acid receptor gene RARß as possible prognostic factor at multiple myeloma
In this study, for the first time the expression of ß <sub>2</sub> and ß <sub>4</sub> isoforms of RARß gene was investigated in group of 19 patients with the newly diagnosed multiple myeloma. The expression of ßoth RARß <sub>2</sub> and RARß <sub>4</sub> isoforms was detected in all patients, ßut it was different and had opposite tendency. We showed that RARß <sub>4</sub> expression level positively correlated with VEGF-A and VEGFR1 expression levels. It was found that higher levels of RARßJVEGF-A/VEGFR1 co-expression were defined of patients with statistically significant increase of plasma cell level and paraprotein concentration. The median overall survival was lower in patients with RARß <sub>4</sub> overexpression, while the maximal median overall survival was oßserved of patients with RARß <sub>2</sub> down-regulation and nearly aßsolute RARß <sub>4</sub> inactivation.