CULATING MICRORNA AS POTENTIAL BIOMARKERS OF MGUS AND MM

Konference: 2013 18th Congress of the European Hematology Association - účast ČR

Téma: Multiple myeloma - Biology

Číslo abstraktu: P752

Autoři: Mgr. Lenka Bešše (Kubiczková); doc. RNDr. Sabina Ševčíková, Ph.D.; MUDr. Elena Dementyeva; MUDr. Fedor Kryukov; prof. RNDr. Ondřej Slabý, Ph.D.; RNDr. Jana Nekvindová, PhD; Mgr. Lenka Radová, Ph.D.; RNDr. Henrieta Grešliková; Prof.RNDr. Petr Kuglík, CSc.; prof. MUDr. Luděk Pour, Ph.D.; prof. MUDr. Zdeněk Adam, CSc.; prof. MUDr. Roman Hájek, CSc.

Background:

MicroRNA, a family of small non-coding regulatory RNA, is implicated in deregulation of critical pathways involved in multiple myeloma (MM). Since they are also present in serum of MM and monoclonal gammopathy of undetermined significance (MGUS) patients (pts) with high stability, they could serve as effective biomarkers for such pts. We have identified a specific serum miRNA profile in newly diagnosed MM and MGUS pts, correlated it with clinical parameters, FISH and survival data.

Aims:

To identify a specific profile of serum miRNAs characteristic for MM and MGUS pts.
To evaluate the association between serum miRNAs and clinical parameters, FISH data, overall survival (OS) and time to progression (TTP).

Methods:

190 serum samples obtained from MM pts, MGUS pts and healthy donors (HD) were evaluated for this study. Screening analysis of 667 miRNAs was performed on 4 MM, 4 HD and 5 MGUS samples with TaqMan Low Density Arrays (TLDA). Levels of 6 differentially expressed miRNAs (p<0.05) between MM and HD were confirmed by quantitative real-time PCR using an absolute quantification approach on 103 MM, 57 MGUS and 30 HD samples. Receiver Operating Characteristic (ROC) analysis was used to calculate specificity and sensitivity of each miRNA and their combination. Univariate Cox proportional hazards survival model was used to evaluate prognostic impact of miRNAs. Biochemical data and cytogenetic characteristics were also available for MM and MGUS pts. P values <0.05 were considered as significant.

Results:

MiRNA TLDA arrays analysis showed 14 differentially expressed miRNAs between MM and HD, but no significantly deregulated miRNAs between MM and MGUS. Therefore, miR-222, miR-130a, miR-34a, miR-744, let-7d and let-7e were further validated on a larger cohort of MM, MGUS and HD samples.

Overall reduction of circulating serum miRNAs was observed in MM and MGUS compared to HD. MiR-744, miR-130a, let-7d and let-7e were significantly downregulated and miR-34a was upregulated in MM and MGUS cohort of pts (all p<0.001). ROC analysis showed highest sensitivity (80.6%), specificity (86.7%) (AUC=0.898) for combination of miR-34a and let-7e to distinguish MM from HD and sensitivity (91.1%), specificity (96.7%) (AUC=0.976) for miR-34a and let-7e combination to distinguish MGUS from HD. Significant positive correlation between low levels of serum miR-744, let-7d, let-7e and levels of hemoglobin (r_S=0.543; 0.508 and 0.585 resp., all p<0.0001), thrombocytes (r_S=0.555; 0.500 and 0.515 resp., all p<0.0001) and albumin (r_S=0.355; 0.385 and 0.355 resp., all p<0.0001) was observed in MM. These miRNAs significantly negatively correlated with levels of creatinine (r_S=-0.415; -0.372 and -0.406, resp., all p<0.0001) and beta₂-microglobulin (r_S=-0.504; -0.447 and -0.529 resp., all p<0.0001). In MGUS, similar correlation pattern with these parameters was observed, except for correlation between miRNA and thrombocytes, where no correlation was found. However; neither in MM, nor in MGUS, the levels of miRNAs correlated with PCs infiltration. Only in MM pts, let-7d and let-7e correlated with del (13q14) (p=0.045 and p=0.019 resp.). Levels of miR-744, let-7d and let-7e showed an inverse correlation with ISS stage (all p<0.0001). Lower levels of miR-744 were found to be significantly connected with worse OS (HR 0.998 [HR95%CI: 0.997; 0.999); p=0.001) and TTP (HR 0.998 [HR95%CI: 0.998; 0.999]; p=0.001).