Bone marrow-derived stromal cells prevent apoptotic cell death in B- lineage acute lymphoblastic leukemia

Abstract

Establishing requirements for the survival of human immature B cells in vitro has proved elusive. In this article, we report prolonged survival of B-lineage leukemic cells on ‘feeder layers’ of bone marrow (BM)- derived stromal cells in a serum-free environment. In 15 of 18 cases of B-lineage acute lymphoblastic leukemia (ALL), there was a greater than 50% decrease in the number of viable cells after 72 hours of culture in medium alone. Cell loss was preceded by molecular and cellular changes characteristic of programmed cell death, or apoptosis, and was not suppressed by adding interleukin-7 to the tissue culture medium. By contrast, the use of allogeneic BM stromal cells as feeder layers prevented apoptosis in 10 of 12 cases of ALL, leading to extended survival of the blast cells. This method was not successful when the allogeneic marrow cells were replaced with established cell lines. In six of eight cases in which the numbers of intact CD19+ lymphoblasts were counted by flow cytometry after 7 days of culture, the proportion of such cells recovered in the presence of BM stromal cells was 68.8% to 124.7% (median, 95.3%) of that originally seeded, as opposed to the 0.3% to 15.9% fraction (median, 0.7%) obtained in the absence of stromal cells. Survival requirements of the B-lineage lymphoblasts appeared to be heterogeneous, as cells from 3 of the 18 cases studied showed no signs of apoptosis in serum-free tissue culture medium that lacked BM stromal cells. The only cells not giving rise to viable cultures were from two hyperdiploid (greater than 50 chromosomes) cases with identical karyotypes. The serum-free assay described here can be used to compare the survival requirements of normal and leukemic B-cell progenitors as well as to identify the molecules involved in the interaction between BM stroma and immature B cells.

A phase 1 study of the CXCR4 antagonist plerixafor in combination with high‐dose cytarabine and etoposide in children with relapsed or refractory acute leukemias or myelodysplastic syndrome: A Pediatric Oncology Experimental Therapeutics Investigators’ Consortium study (POE 10‐03)

“…The primary objective of this phase 1 trial was to determine the safety and tolerability of plerixafor in combination with re-induction chemotherapy in pediatric and young adult patients with relapsed or refractory acute leukemias and MDS. Secondary objectives were to (1) estimate the response rate, (2) determine the pharmacokinetics (PK) of plerixafor in this treatment regimen and patient population, (3) quantify mobilization of leukemic blasts into the peripheral blood, (4) measure the quantitative expression of CXCR4 on leukemic blasts at baseline, and (5) evaluate changes in quantitative expression of CXCR4 on residual leukemic blasts after cycle 1. This phase 1 dose-escalation study utilized the rolling six-trial design, 29 which allowed between two and six patients to be enrolled concurrently onto a given dose level.…”

Genetic alterations determine chemotherapy resistance in childhood T‐ALL: modelling in stage‐specific cell lines and correlation with diagnostic patient samples

“…While most of these drug resistance studies have used only the CCRF-CEM or MOLT-4 cell lines (McGrath et al, 1989;Li et al, 1997), CCRF-CEM cells represent a Pre-T (CD1a ) surface CD3 ) ) stage of differentiation (Burger et al, 1999), and MOLT-4 shows immunophenotypic and genotypic features of natural kill (NK) cells. Furtheremore, while the direct investigation of patient samples remains an important goal in translational research, such studies are often difficult to conduct ex vivo (Manabe et al, 1992).…”

Irradiated fibroblasts protect burkitt lymphoma cells from apoptosis by a mechanism independent of BCL‐2

“…Firstly, primary tumor cells of mouse plasmacytoma, freshly induced by intraperitoneal injection of pristane into BALB/c mice, can only survive and proliferate when explanted onto a layer of peritoneal stromal cells (Degrassi et al, 1990). Similarly, human acute B-lymphoblastic leukemia cells are protected from apoptosis through contact with bone-marrow stromal cells (Manabe et aL, 1992). Given the pathogenetic similarities between mouse plasmacytoma, B lymphoblastic leukemia and Burkitt's lymphoma (Klein, 1983), the primary dependence on mesenchymal stromal cells may be regarded as a characteristic feature of high-grade B-cell malignancies of the small non-cleaved type which involve the typical myc-Ig chromosomal translocations, regardless of a leukemic or lymphomatous presentation.…”