Differences and similarities are observed in Pax5 isoform usage in malignant and normal B-cell–enriched populations.

(A) RT-PCR products of 3′-ends of the coding region of Pax5 transcripts differ between malignant and normal B cell–enriched populations. (B) Alternative Pax5 d/e is expressed in both malignant and normal B cell–enriched populations. Shown in panel A are RT-PCR products that were generated with a pair of primers designed to amplify a 754-bp product in the 3′-end of the coding region of Pax5. All templates were mRNA derived from B cell–enriched populations. P indicates MM patient; H, healthy donor. (Lane M) A 100-bp ladder (Boehringer Mannheim). (Lane 1) A no-template control. (Lanes 2-7) Patients P9, P15, and P16 had not yet received any chemotherapy at the time of the BM harvest; patients P7, P11, and P14 had received treatment with chemotherapy at the time of the BM harvest (Table 2). The expected 754-bp product is faintly observed in 2 treated patients (P7 and P11) but in none of the untreated patients. (Lanes 8-10) The expected 754-bp product is expressed in all 3 healthy subjects. All other products observed with this primer pair were nonspecific. (B) (Lane 1) A no-template control. (Lanes 2-10) All MM patients, treated and untreated, and all healthy subjects express the alternative Pax5d/e isoform.