Expression and prognostic value of FAS receptor/FAS ligand and TrailR1/TrailR2 in acute myeloid leukemia.

We studied the expressions of FR, FL, TR1, and TR2 on blasts and T cells from 71 patients with acute myeloid leukemia (AML) and correlated expression rates with the clinical course. Compared to AML-blasts we found higher co-expressions on healthy myeloid and T cells. Expression of all markers on blasts and on T cells was similar in different subtypes and acute stages of AML. Compared to the non-responders (n = 7) responders to the AML Cooperative Group-therapy (n = 22) presented with higher proportions of blasts co-expressing the four markers (FR: 32 vs 15%; FL: 15 vs 13%; TR1: 72 vs 37%; TR2: 24 vs 23%) or T cells (FR: 88 vs 71%; FL: 76 vs 56%; TR1: 96 vs 44%; TR2: 54 vs 42%). Patients with higher expression rates of TR1 on blasts (≥ 48%) and on T cells (≥ 67%) were characterized by a prolonged survival. In summary, our data show a variable expression of FR, FL, TR1 and TR2 on blasts or T cells in different subgroups of AML. Higher co-expression rates of FR, FL, TR1 and TR2 were characterized by a better prognosis for the patients with respect to achieve a remission and to survive. Functional analyses should be performed to find out those patients in who induced upregulation of these markers could contribute to overcome drug resistance.

Use of NG2 (7.1) in AML as a tumor marker and its association with a poor prognosis.

We analyzed 70 bone marrow (BM) samples from acute myeloid leukemia (AML) patients for 11q23 aberrations and reactivity with the monoclonal antibody NG2. NG2 reactivity correlated with FAB-M5 (50% positive cases, with an average of 32% NG2(+) cells), as well as with 11q23 aberrations. We detected NG2(+) cells in AML cases with normal karyotype, however, not in healthy BM cells. This means that NG2 qualifies as a reliable AML blast tumor marker, enabling monitoring of the course of AML independently of, although often associated with, 11q23-aberrations. Patients with more than 10% NG2(+) cells showed a tendency to have a shorter progression-free survival (mean: 7 months) than patients with fewer than 10% NG2(+) cells (mean survival: 17 months; p=0.08). While 31% of the patients with NG2(+) cells responded to chemotherapy, 58% of the group with NG2(+) cells did not respond (p=0.047). In conclusion, NG2 detects many, but not all 11q23 aberrations and other cases without 11q23 aberrations. However, it does not react with healthy BM cells, thereby contributing to the detection of patients with poor prognosis.