In addition, we included in the analyses 20 normal samples, 22 MGUS, and 137 MM from two publicly available MM gene expression datasets [ 1, 27].
Chi et al. performed miRNA expression profiling in PCs from 33 MM patients, 5 MGUS cases, 4 HMCLs, and 5 healthy donors.
Patients database included the proprietary database (4 normal samples, 12 MGUS, 132 MM, and 9 PCL), together with 20 normal samples, 22 MGUS, and 137 MM taken from 2 publicly available MM gene expression datasets [ 1, 27] (GSE6477 and GSE6691, CEL files available at Gene Expression Omnibus [ 26]), all profiled on HG-U133A.
We next used aCGH to analyze copy-number alterations in 67 MM and 6 MGUS samples, and assessed their association with the level of repetitive-element methylation.
All 32 MGUS patients (100%) showed two immunophenotypically different plasma cell populations, one with a normal and the other with an aberrant phenotype.
We elucidated the complete (miRBase v.10.1) microRNA profile of CD138+ plasma B-cells from bone marrow of 33 MM patients, 5 MGUS, 9 controls, and 4 well established MM cell lines (NCI-H929, JJN3, Thiel and RPMI-8226).
Methylated DNA was enriched from 0.5 to 2 µg of genomic DNA obtained from 9 MM, 3 MGUS and 3 NPC specimens (MethylaMiner™Methylated DNA Enrichment Kit; Life Technologies Corp., Carlsbad, CA, USA) according to the manufacturer's instructions.
Therefore we undertook a comprehensive study using microarray technology to elucidate the complete miRNome (miRBase version 13.0) of purified tumor (CD138+) cells from the bone marrow of 33 MM and 5 MGUS patients (and 9 controls).
In a recent study of 100 untreated patients (73 myeloma, 27 MGUS) using WB-MRI, almost 50% of all observed deposits would have been missed using spinal MRI only.
In one study comparing whole-body MRI and the skeletal survey in 54 patients (47 myeloma, 7 MGUS) WB-MRI correctly revealed marrow deposits in 74% of patients versus 55% for the skeletal survey.
