High Expression Levels of Long Noncoding RNA Small Nucleolar RNA Host Gene 18 and Semaphorin 5A Indicate Poor Prognosis in Multiple Myeloma

Background:The aim of this study was to detect the expression of long noncoding RNA small nucleolar RNA host gene 18 (SNHG18) andsemaphorin 5A (SEMA5A) genes in multiple myeloma (MM) patients and to explore the correlation of the expression of these genes with the clinical characteristics and prognosis of MM patients.Methods:Forty-seven newly diagnosed MM, 18 complete remission MM, 13 refractory/relapse MM, and 22 iron deficiency anemia (serving as control) samples were extracted at the Department of Hematology, Second Affiliated Hospital of Xian Jiaotong University between January 2015 and December 2016. The clinical features of the MM patients are summarized. Real-time quantitative PCR was performed to analyze the relative expression levels of theSNHG18andSEMA5Agenes. The clinical characteristics and overall survival (OS) of the MM patients were statistically analyzed while measuring different levels ofSNHG18andSEMA5Agene expression. At the same time, the correlation between the expression ofSNHG18andSEMA5Awas also analyzed.Results:The analysis confirmed thatSNHG18and its possible target geneSEMA5Awere both highly expressed in newly diagnosed MM patients. After analyzing the clinical signi?cance ofSNHG18andSEMA5Ain MM patients, we found that the expression ofSNHG18andSEMA5Awas related to the Durie-Salmon (DS), International Staging System (ISS), and Revised International Staging System (R-ISS) classification systems, and the Mayo Clinic Risk Stratification for Multiple Myeloma (mSMART;p< 0.05). Moreover, we observed a significant difference in OS between theSNHG18/SEMA5Ahigh expression group and the low expression group. We found a positive correlation betweenSNHG18andSEMA5Aexpression (r= 0.709,p< 0.01). Surprisingly, the expected median OS times of both theSNHG18andSEMA5Ahigh expression groups were significantly decreased, which was in contrast to those of both theSNHG18andSEMA5Alow expression groups and the single-gene high expression group (p<0.05).Conclusion:High expression of bothSNHG18andSEMA5Ais associated with poor prognosis in patients with MM.