Deregulated Expression of Long Non-coding RNA HOX Transcript Antisense RNA (HOTAIR) in Egyptian Patients with Multiple Myeloma.

Increasing evidence of involvement of non-coding RNAs, especially long non-coding RNAs (lncRNAs), in the molecular biology of various malignancies have been recently reported. Their utilization as markers for diagnosis, prognosis and evaluation of treatment response was widely investigated. As the impact of lncRNA HOTAIR on multiple myeloma (MM) was not properly highlighted, we aimed to explore the expression levels of HOTAIR in three groups of MM patients and to analyze its relationship to different patients' characteristics. Plasma samples were withdrawn from 24 newly diagnosed MM patients, 23 post-therapy patients in complete response (CR) or very good partial response (VGPR) and 15 patients who had either progressive disease (PD) or relapse. The expression of lncRNA HOTAIR in MM patients and 20 healthy controls was analyzed by quantitative reverse transcription polymerase chain reactions. HOTAIR was significantly upregulated in newly diagnosed and PD/relapse categories in comparison with controls and MM patients who had achieved CR or VGPR (P < 0.001). Furthermore; HOTAIR expression levels correlated with the percentage of malignant plasma cells in bone marrow (P = 0.006) and disease stage (ISS stage) (P = 0.031). HOTAIR may be employed as  prognostic molecular marker and novel therapeutic tool for newly diagnosed MM patients.