Elevated serum lncRNA TUG1 levels are a potential diagnostic biomarker of multiple myeloma

Long noncoding RNAs (lncRNAs) have increasingly been found to be key mediators of tumor biology and to have potential diagnostic value as biomarkers of particular forms of cancer. TUG1 (taurine-upregulated gene 1) is an lncRNA that has been found to be upregulated in a range of different cancer types, but levels of its expression in the serum of patients with multiple myeloma (MM) are uncertain, as is its diagnostic relevance in such a population. This study therefore explored whether TUG1 levels in patient serum serve as a diagnostic biomarker of MM. We analyzed serum TUG1 levels via quantitative real-time polymerase chain reaction in healthy control and MM patient serum and observed clear TUG1 upregulation in MM patients (p < 0.001). We further found that the levels of TUG1 in patient serum correlated with factors including disease clinical stage, β₂-microglobulin, total protein, albumin, globulin, and bone injury (p < 0.05), suggesting that this lncRNA may be independently predictive of MM disease stage. We found areas under receiver operating characteristic curves as high as 0.792 (p < 0.001) for TUG1-a value higher than that for either β₂-microglobulin (0.747) or albumin (0.597)-with the combination of all three biomarkers improving diagnostic specificity and areas under the curve of 96.9% and 0.836, respectively (p < 0.001). Together, our results suggest that serum TUG1 levels may serve as a valuable biomarker that can help to facilitate MM diagnosis.