Comparable patterns of RHAMM isoform expression by PC in individual and aggregate PC
MM patients nos. . | RHAMM-exon4/RHAMMFL ratio ± SE in 1000 PC . | No. cells examined . | RHAMMFL expression (%) . | RHAMM-exon4 expression (%) . | Both (%) . | Absent (%) . |
|---|---|---|---|---|---|---|
| 1 | 0.404 ± 0.01 | 24* | 20 | 2 | 1 | 1 (4.2) |
| 2 | 0.548 ± 0.18 | 35* | 11 | 6 | 3 | 15 (42.9) |
| 3 | 0.565 ± 0.13 | 24* | 4 | 2 | 1 | 17 (70.8) |
| 4 | 0.655 ± 0.06 | 17* | 8 | 0 | 0 | 9 (52.9) |
| 5 | 0.802 ± 0.07 | 15* | 4 | 2 | 0 | 9 (60.0) |
| 6 | 0.875 ± 0.001 | 46* | 21 | 6 | 3 | 16 (34.8) |
| 7 | 0.987 ± 0.02 | 29* | 4 | 2 | 1 | 22 (75.9) |
| 8 | 1.799 ± 0.01 | 24* | 3 | 14 | 4 | 3 (12.5) |
| Mean, MM | NA | 26.8* | 9.4 (35.0) | 4.3 (15.9) | 1.6 (6.1) | 11.5 (43.0) |
| Control patients, n = 3 | UD | 92† | 8 (8.7) | 8 (8.7) | 18 (19.6) | 58 (63.0) |
MM patients nos. . | RHAMM-exon4/RHAMMFL ratio ± SE in 1000 PC . | No. cells examined . | RHAMMFL expression (%) . | RHAMM-exon4 expression (%) . | Both (%) . | Absent (%) . |
|---|---|---|---|---|---|---|
| 1 | 0.404 ± 0.01 | 24* | 20 | 2 | 1 | 1 (4.2) |
| 2 | 0.548 ± 0.18 | 35* | 11 | 6 | 3 | 15 (42.9) |
| 3 | 0.565 ± 0.13 | 24* | 4 | 2 | 1 | 17 (70.8) |
| 4 | 0.655 ± 0.06 | 17* | 8 | 0 | 0 | 9 (52.9) |
| 5 | 0.802 ± 0.07 | 15* | 4 | 2 | 0 | 9 (60.0) |
| 6 | 0.875 ± 0.001 | 46* | 21 | 6 | 3 | 16 (34.8) |
| 7 | 0.987 ± 0.02 | 29* | 4 | 2 | 1 | 22 (75.9) |
| 8 | 1.799 ± 0.01 | 24* | 3 | 14 | 4 | 3 (12.5) |
| Mean, MM | NA | 26.8* | 9.4 (35.0) | 4.3 (15.9) | 1.6 (6.1) | 11.5 (43.0) |
| Control patients, n = 3 | UD | 92† | 8 (8.7) | 8 (8.7) | 18 (19.6) | 58 (63.0) |
CD138+ or CD38+ PCs derived from BM aspirates were sorted into PCR tubes containing lysis buffer at 1 cell/tube or 1000 cells/tube and stored at −80°C. RT-PCR was performed as outlined in “Patients, materials, and methods” using RHAMM-specific primers that flank exon 4. Only cDNA samples that were positive for both β2-microgobulin (MM and control) and clonal message (MM) are tabulated. Single-cell RT-PCR products were precipitated prior to GeneScan analysis. RHAMM-specific RT-PCR amplification of 1000 cells/well samples resulted in 2 product peaks representing RHAMM-exon4 product (150 bp) and RHAMMFL product (200 bp). The area under each peak was calculated by GeneScan Analysis software and exported to Microsoft Excel to determine the ratio of RHAMM-exon4/RHAMMFL peak intensities. RHAMM ratios were unobtainable from 1000 PCs/well (n = 3 patients examined) and bulk BM (n = 4 patients examined) populations from 7 control patient populations.
UD indicates unable to determine; NA indicates not applicable.
Clonal cells examined.
Plasma cells examined.