Hematopoietic cell transplantation in patients with myelodysplastic syndrome or acute myeloid leukemia arising from myelodysplastic syndrome: similar outcomes in patients with de novo disease and disease following prior therapy or antecedent hematologic disorders.

We analyzed outcomes after hematopoietic cell transplantation (HCT) in 257 patients, 3 to 72.7 years old (median, 43 y), with secondary myelodysplastic syndrome (MDS) including those with transformation to acute myeloid leukemia (tAML). Conditioning regimens included high-dose total-body irradiation (TBI)/chemotherapy (n = 83); busulfan (BU)/cyclophosphamide (CY) (BUCY, n = 122; with BU targeting [tBUCY], n = 93); fludarabine (Flu) with tBU (FLUtBU; n = 12); Flu plus 200 cGy TBI (n = 26); and miscellaneous regimens (n = 14). Donors were HLA-identical or partially mismatched family members in 135 and unrelated individuals in 122 patients. Five-year relapse-free survival was highest (43%) and nonrelapse mortality lowest (28%) among tBUCY-conditioned patients. Outcomes were compared with results in 339 patients who received transplants for de novo MDS/tAML, and a multivariate analysis failed to show significant differences in outcome between the 2 cohorts. Relapse probability and relapse-free survival correlated significantly with disease stage (P < .001) and karyotype (P < .001). Relapse incidence was lower (P = .003) and relapse-free survival superior (P = .02) with unrelated donor transplants. The data suggest that overall inferior outcome in patients with secondary MDS/tAML was related to the frequency of high-risk cytogenetics. For both cohorts, transplantation outcomes improved over the time interval studied.

Cytogenetic characterization and H-ras associated transformation of immortalized human mammary epithelial cells.

INTRODUCTION: Immortalization is a key step in malignant transformation, but immortalization alone is insufficient for transformation. Human mammary epithelial cell (HMEC) transformation is a complex process that requires additional genetic changes beyond immortalization and can be accomplished in vitro by accumulation of genetic changes and expression of H-ras. METHODS: HMEC were immortalized by serial passaging and transduction with the catalytic subunit of the human telomerase gene (hTERT). The immortalized cells were passaged in vitro and studied by a combination of G-banding and Spectral Karyotyping (SKY). H-ras transduced, hTERT immortalized cells were cloned in soft agar and injected into nude mice. Extensive analysis was performed on the tumors that developed in nude mice, including immunohistochemistry and western blotting. RESULTS: Immortal HMEC alone were not tumorigenic in gamma-irradiated nude mice and could not grow in soft agar. Late passage hTERT immortalized HMEC from a donor transduced with a retroviral vector containing the mutant, autoactive, human H-ras61L gene acquired anchorage independent growth properties and the capacity for tumorigenic growth in vivo. The tumors that developed in the nude mice were poorly differentiated epithelial carcinomas that continued to overexpress ras. These cells were resistant to doxorubicin mediated G1/S phase arrest but were sensitive to treatment with a farnesyltransferase inhibitor. CONCLUSION: Some of the cytogenetic changes are similar to what is observed in premalignant and malignant breast lesions. Despite these changes, late passage immortal HMEC are not tumorigenic and could only be transformed with overexpression of a mutant H-ras oncogene.

Allogeneic hematopoietic cell transplantation for infants with acute lymphoblastic leukemia.

The role of transplantation in infants with acute lymphoblastic leukemia (ALL) is not defined. We analyzed results of 40 infants diagnosed before age 12 months who received a hematopoietic cell transplant (HCT) between July 1982 and February 2003 in first complete remission (CR1; n = 17), CR2/3 (n = 7), or relapse (n = 16). Patients were conditioned with cyclophosphamide with total body irradiation (n = 39) or busulfan (n = 1). Donors were matched related (n = 8), mismatched related (n = 16), or unrelated (n = 16). Graft-versus-host disease (GVHD) prophylaxis was methotrexate or cyclosporine (n = 7) or methotrexate plus cyclosporine (n = 33). Thirty-nine patients engrafted, 20 developed acute GVHD, and 7 developed chronic GVHD. Sixteen patients relapsed and 7 died of other causes. Patients in CR1 had disease-free survival (DFS) of 76% compared with 45% for CR2/CR3 and 8% for relapse (P < .001). Of 33 patients with cytogenetic data, 26 (79%) had MLL gene rearrangement. Fourteen of these 26 were in CR1 and 11 survive in remission. Outcome was associated with phase of disease, but having the MLL gene was not a factor predictive of outcome. Late effects included growth and other hormone deficiencies. These data demonstrate that infants with ALL and MLL gene have excellent DFS when they received transplants in CR1, and consideration for transplantation in CR1 is warranted.

Production of spindle cell carcinoma by transduction of H-Ras 61L into immortalized human mammary epithelial cells.

Human mammary epithelial cells (HMEC) were immortalized by serial passaging through senescence (M0) and subsequent transduction with the catalytic subunit of the human telomerase gene (hTERT). These cells acquired multiple non-random cytogenetic abnormalities with lengthy passaging in vitro, but are still not tumorigenic in irradiated nude mice and cannot grow in soft agar. Transduction, of late passage immortal HMEC from a single donor, with a retroviral vector containing the mutant autoactive H-Ras 61L gene, enabled immortal HMEC to acquire anchorage independent growth properties. Three colonies were picked and all three were found to be tumorigenic. One colony exclusively produced epithelial tumors in nude mice, but the other two colonies gave rise exclusively to malignancies in which the cells displayed a spindle morphology. In this paper we describe the characteristics of the tumors arising from one of these 'spindle colonies'. These tumors were strongly positive for vimentin staining and virtually negative for pan-cytokeratin staining, on immunohistochemistry. Cytogenetic analysis of the cells derived from these tumors confirmed that they were derived from the original cultured, immortalized mammary cells. We conclude that the HMEC have undergone metaplastic transformation due to the high levels of H-Ras 61L and telomerase activity that they display, and the derived tumors are best described as spindle cell carcinomas.

Predictors of relapse and overall survival in Philadelphia chromosome-positive acute lymphoblastic leukemia after transplantation.

Allogeneic transplantation offers a potential cure for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). We performed a retrospective analysis examining pretransplantation and posttransplantation prognostic factors in 90 patients with Ph+ ALL. The median age of the patients was 33 years, with slightly more than half of the patients (58%) in clinical remission at the time of transplantation. Overall, patients had a nonrelapse mortality rate of 30%, a relapse percentage of 34%, and an estimated 5-year disease-free survival rate of 30%. Pretransplantation risk factors for relapse included the expression of the p190 transcript (relative risk [RR] = 5.1; P =.037), evidence of morphologic disease at the time of transplantation (RR = 3.9; P <.001), and type of donor (RR = 2.5; P =.015), with patients receiving autologous or matched related transplants having the highest risk of relapse. The detection of minimal residual disease by reverse transcription polymerase chain reaction for bcr-abl transcripts was a significant posttransplantation risk factor for relapse (RR = 4.4; P =.001), with posttransplantation patients expressing the p190 transcript having the highest risk of relapse (RR = 8.7; P =.0001). In addition, patients with chronic extensive graft-versus-host disease showed a significantly lower risk of relapse (RR = 0.33; P =.038). Thus, these findings indicate that several pretransplantation and posttransplantation risk factors exist for patients with Ph+ ALL. Together, these factors can be used to improve our risk stratification of patients with Ph+ ALL who undergo transplantation, which will greatly enhance our ability to counsel these patients and potentially lead to the development of more specific treatment plans for them.

NOD/SCID mice transplanted with marrow from patients with myelodysplastic syndrome (MDS) show long-term propagation of normal but not clonal human precursors.

Sublethally irradiated NOD/SCID mice were transplanted with hematopoietic progenitor cells obtained from the marrow of patients with myelodysplastic syndromes (MDS). Engraftment of MDS cells, as determined by flow cytometry, was delayed compared to marrow from normal donors. Human CD38(+)CD34(-) cells were prominent in marrows and spleens of MDS chimeras. CD34(+)CD38(-), CD34(+)CD38(+) and T cells were also easily detected. Human myeloid cells (CD33(+); CD15(+)) were present in low proportions. No clonal precursors were identified by fluorescent in situ hybridization (FISH) or by molecular analysis of polymorphic X-linked markers in mice with documented engraftment of human cells more than 2 months after transplantation. These data indicate that human cells present in murine MDS chimeras, at the levels of sensitivity of our assays, were derived from residual normal cells in human MDS marrow, and suggest that the NOD/SCID environment was not conducive to the expansion of clonal MDS precursors. This model may allow identification of factors relevant for sustaining or expanding clonal precursors.

p53 and p21 form an inducible barrier that protects cells against cyclin E-cdk2 deregulation.

BACKGROUND: Cyclin E, in conjunction with its catalytic partner cdk2, is rate limiting for entry into the S phase of the cell cycle. Cancer cells frequently contain mutations within the cyclin D-Retinoblastoma protein pathway that lead to inappropriate cyclin E-cdk2 activation. Although deregulated cyclin E-cdk2 activity is believed to directly contribute to the neoplastic progression of these cancers, the mechanism of cyclin E-induced neoplasia is unknown. RESULTS: We studied the consequences of deregulated cyclin E expression in primary cells and found that cyclin E initiated a p53-dependent response that prevented excess cdk2 activity by inducing expression of the p21Cip1 cdk inhibitor. The increased p53 activity was not associated with increased expression of the p14ARF tumor suppressor. Instead, cyclin E led to increased p53 serine15 phosphorylation that was sensitive to inhibitors of the ATM/ATR family. When either p53 or p21cip1 was rendered nonfunctional, then the excess cyclin E became catalytically active and caused defects in S phase progression, increased ploidy, and genetic instability. CONCLUSIONS: We conclude that p53 and p21 form an inducible barrier that protects cells against the deleterious consequences of cyclin E-cdk2 deregulation. A response that restrains cyclin E deregulation is likely to be a general protective mechanism against neoplastic transformation. Loss of this response may thus be required before deregulated cyclin E can become fully oncogenic in cancer cells. Furthermore, the combination of excess cyclin E and p53 loss may be particularly genotoxic, because cells cannot appropriately respond to the cell cycle anomalies caused by excess cyclin E-cdk2 activity.

Conditioning with targeted busulfan and cyclophosphamide for hemopoietic stem cell transplantation from related and unrelated donors in patients with myelodysplastic syndrome.

A total of 109 patients (aged 6-66 years; median, 46 years) with myelodysplastic syndrome (MDS) were treated with busulfan (BU) targeted to plasma concentrations of 800 to 900 ng/mL plus cyclophosphamide (CY), 2 x 60 mg/kg, and hemopoietic stem cell (HSC) transplantation from related (n = 45) or unrelated donors (n = 64). At the time of transplantation, 69 patients had less than 5% myeloblasts in the marrow, and 40 patients had more advanced disease. All but 2 evaluable patients had engraftment. The Kaplan-Meier estimates of 3-year relapse-free survival (RFS) were 56% for related and 59% for unrelated recipients. The cumulative incidences of relapse were 16% for related and 11% for unrelated recipients. Nonrelapse mortality (NRM) at 100 days (3 years) was 12% (28%) for related and 13% (30%) for unrelated recipients. The only factor significant for RFS was the etiology of MDS (de novo better than treatment related; P =.03). Factors significantly correlated with relapse were advanced French-American-British classification (P =.002) and International Prognostic Scoring System score (P =.009), poor-risk cytogenetics (P =.03), and treatment-related etiology (P =.03). None of the factors examined was statistically significant for NRM. Patient age and donor type had no significant impact on outcome. RFS tended to be superior in patients receiving transplants with peripheral blood rather than marrow stem cells. Thus, a targeted BUCY regimen provided effective transplant conditioning for patients with MDS receiving transplants from HLA-identical siblings or alternative donors. Although there was still considerable nonrelapse morbidity and mortality, the present regimen was used successfully even in patients older than 60 years of age.

Failure of adult marrow-derived stem cells to generate marrow stroma after successful hematopoietic stem cell transplantation.

OBJECTIVE: The existence of adult, marrow-derived stem cells that retain the ability to generate various tissues is an appealing concept that has considerable therapeutic potential. The aim of this study was to test the extent of this proposed plasticity by defining the ability of adult marrow and peripheral blood stem cells to generate stromal cells of the marrow microenvironment. PATIENTS AND METHODS: We examined expanded populations of stromal cells from four patients 1 to 27 years after allogeneic, sex-mismatched marrow, or peripheral blood stem cell transplantation. The cultured stromal cells were stained by immunofluorescence and with nonspecific esterase (NSE) to detect macrophages, which can constitute a significant component of a primary long-term marrow culture. Fluorescence in situ hybridization (FISH) probes for chromosomes X and Y were applied to distinguish donor from host cells. RESULTS: FISH analysis of replicate slides indicated a good correlation between the number of NSE(+) cells and the number of donor-derived cells. By applying NSE and FISH to the same cells and capturing both bright-field and epifluorescence images, we confirmed that all donor signals were derived from NSE(+) macrophages. CONCLUSION: After successful allogeneic stem cell transplantation, the marrow stroma remains host in origin, even after 27 years of 100% donor hematopoiesis.

Hematopoietic stem cell transplantation for advanced myelodysplastic syndrome after conditioning with busulfan and fractionated total body irradiation is associated with low relapse rate but considerable nonrelapse mortality.

The objectives of this study were to develop transplantation regimens for patients with advanced myelodysplastic syndrome (MDS) that would be associated with low transplantation-related mortality and improved relapse-free survival. Sixty patients with advanced MDS or acute myeloid leukemia evolving from MDS (sAML), 12 to 62 years old (median, 40 years), were conditioned with busulfan (7 mg/kg) and TBI (6 x 200 cGy) (BU/TBI) and received transplants from related (n = 20) or unrelated donors (n = 40). By French-American-British (FAB) criteria, 21 patients had refractory anemia with excess blasts (RAEB), 16 had RAEB in transformation (RAEB-T), 15 had sAML, and 8 had chronic myelomonocytic leukemia (CMML). By International Prognostic Scoring System (IPSS) criteria, 1 patient had low, 10 had intermediate-1, 13 had intermediate-2, and 31 had high-risk MDS (5 patients had proliferative CMML). All evaluable patients achieved sustained engraftment. The cumulative incidence (CI) of acute GVHD grades II to IV was 83% with unrelated donors and 85% with related donors. The CI of relapse was 25% at 3 years. The incidence of nonrelapse mortality (NRM) at 100 days was 38%. The Kaplan-Meier estimate of survival was 26% at 3 years. Major causes of death were relapse, organ failure, GVHD, and infection. In multivariate analysis, improved relapse-free survival was associated with good cytogenetic risk (P = .002) and shorter disease duration (P = .004). NRM was increased with longer disease duration (P = .0002), positive cytomegalovirus serology (P = .02), and male sex (P = .02). Relapse was associated with poor cytogenetic risk (P = .0004). Thus, BU/TBI conditioning as used in this trial was associated with relapse rates comparable to those observed with a previously used more intensive regimen combining BU/TBI with cyclophosphamide. However, despite the omission of cyclophosphamide, transplantation-related morbidity and mortality were considerable, particularly with transplants from unrelated donors. Future trials should explore the efficacy and tolerability of reduced-intensity conditioning regimens.