Biomedical subjects

M Andreeff

Publications and source records attributed to M Andreeff.

At least 145 records · Page 8Linked to original sources

PubMed1995

Allogeneic blood stem cell transplantation: peripheralization and yield of donor-derived primitive hematopoietic progenitor cells (CD34+ Thy-1dim) and lymphoid subsets, and possible predictors of engraftment and graft-versus-host disease.

Apheresis-derived hematopoietic progenitor cells have recently been used for allogeneic transplantation. Forty-one normal donors were studied to assess the effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) (12 micrograms/kg/d) on the peripheralization of hematopoietic progenitor cells and lymphoid subsets. The white blood cell, polymorphonuclear cell (PMNC), and lymphocyte concentrations at the peak of rhG-CSF effect in the donor's peripheral blood (PB) exceeded baseline by 6.4-, 8.0-, and 2.2-fold, respectively. Corresponding concentrations of PB CD34+ cells and primitive subsets such as CD34+ Thy-1dim, and CD34+ Thy-1dim CD38- cells increased by 16.3-fold, 24.2-fold, and 23.2-fold, respectively in eight normal donors. The percentage of CD34+ Thy-1dim and CD34+ Thy-1dim CD38- cells among CD34+ cells increased as well, suggesting an additional peripheralization effect of rhG-CSF on primitive CD34+ subsets. The preapheresis PB CD34+ and CD34+ Thy-1dim cell concentrations were predictive of their corresponding apheresis yield per liter of donor blood processed PB lymphoid subsets were not significantly affected by rhG-CSF treatment. The mean apheresis-derived yield of CD34+, CD34+ Thy-1dim, and CD34+ Thy-1dim CD38- cells per kilogram of recipient body weight and per liter of donor blood processed was 48.9 x 10(4) (n = 41), 27.2 x 10(4) (n = 10), and 1.9 x 10(4) (n = 10), respectively. As compared with 43 single bone marrow (BM) harvest, the CD34+ cell yield of peripheral blood progenitor cell allografts of 41 normal donors exceeded that of BM allografts by 3.7-fold and that of lymphoid subsets by 16.1-fold (CD3+), 13.3-fold (CD4+), 27.4-fold (CD8+), 11.0-fold (CD19+), and 19.4-fold (CD56+CD3-). All PBPC allografts were cryopreserved before transplantation. The mean recovery of CD34+ cells after freezing, thawing, and washing out dimethylsulfoxide was 86.6% (n = 31) and the recovery of lymphoid subsets was 115.5% (CD3+), 121.4% (CD4+), 105.6% (CD8+), 118.1% (CD19+), and 102.4% (CD56+CD3-). All donors were related to patients: 39 sibling-to-sibling, 1 parent-to-child, and 1 child-to-parent transplant. Thirty-eight transplants were HLA fully identical, two transplants differed in one and two antigens. Engraftment occurred in 38 recipients; two patients died too early to be evaluated, and one patient did not engraft. The lowest CD34+ cell dose transplanted and resulting in complete and sustained engraftment was 2.5 x 10(6)/kg of recipient body weight. There was no significant correlation between the total number of CD34+ cells transfused and the time to reach PMNC >0.5 x 10(9)/L or platelets > 50 x 10(9)/L posttransplant, nor was there a correlation found between the total number of CD3+, CD4+, and CD8+ cells transfused and the development of acute graft-versus-host disease (GVHD). The actuarial probability of developing acute GVHD in 38 evaluable patients was 48%. In 13 patients followed longer than 100 days posttransplant, the actuarial probability of developing chronic GVHD was 66% (median follow-up, 264 days).

Adolescent↗

PubMed1995

In vivo biologic effects of PIXY321, a synthetic hybrid protein of recombinant human granulocyte-macrophage colony-stimulating factor and interleukin-3 in cancer patients with normal hematopoiesis: a phase I study.

PIXY321 is a novel fusion protein of recombinant human granulocyte-macrophage colony-stimulating factor and interleukin-3 that exhibits biologic effects of both its parent cytokines in vitro and in preclinical studies. To evaluate the clinical safety and hematopoietic effects of this hybrid cytokine, PIXY321 was administered by subcutaneous injection twice daily at doses of 25 to 1,000 micrograms/m2/day over 14 days to 24 patients with sarcoma before chemotherapy as part of a phase I trial. The treatment was associated with significant increases in white blood cell, neutrophil, platelet, and reticulocyte counts (all P < .001). The increase in neutrophil count was dose-related and was seen during treatment with the cytokine, whereas the increase in platelet count was gradual and peaked after the cessation of the cytokine treatment and was not clearly dose related. PIXY321 treatment also increased bone marrow (BM) cellularity and the percentage of BM cells in S phase (P < .001). In addition, there was a significant increase in the number of CD34+ cells and committed and multipotential progenitors in the peripheral blood. The ex vivo expansion capacity of peripheral blood and BM progenitor cells was preserved after the in vivo treatment with PIXY321. The treatment was well tolerated, with the most common side-effect being injection site reactions. The results of this study show the biologic and clinical activity of a genetically engineered fusion molecule of two hematopoietic cytokines in humans with normal hematopoietic function.

Agranulocytosis↗

PubMed1995

Chromosome X numerical abnormalities in patients with non-Hodgkin's lymphoma. A study of 59 patients using fluorescence in situ hybridization.

Chromosome X numerical abnormalities are frequently observed in non-Hodgkin's lymphoma (NHL), with an incidence of 3% to 14% for chromosomal loss and 7% to 33% for chromosomal gain. Because sex chromosome numerical abnormalities are thought to be due to aging, little information is known about their relation to gender, therapy, and prognosis. Therefore, to determine the incidence and clinical relevance of this abnormality in NHL, we studied specimens from 59 NHL patients (31 men and 28 women) by fluorescence in situ hybridization (FISH) using a directly conjugated centromeric probe for chromosome X. The median age for the entire group was 52 years (range, 31-88 years). All specimens were obtained by fine-needle aspiration of diseased lymph nodes. Sex-matched lymphocytes from benign hyperplastic lymph nodes were used as controls. The overall incidence of chromosome X numerical abnormalities was 49.2%. Female patients had a higher overall incidence than males (76% vs. 24%; p < 0.001). The median percentage of cells involved in this abnormality in each specimen was 5.2%. There was no statistically significant difference in the incidence in previously treated than untreated patients (53.1% vs. 44.4%; p < 0.75) and in intermediate-grade NHL than low-grade NHL (61.1% vs. 50%; p < 0.75). There was a trend towards a higher incidence of chromosome X loss in older patients. While the difference in the incidence of chromosome X abnormalities observed between women and men may be due to the difference in the normal copy numbers of this chromosome in each sex group, this abnormality remained higher than any other autosomal chromosome abnormality in NHL previously evaluated by FISH. We conclude that, although FISH detected a high incidence of chromosome X numerical abnormalities and that females had a higher incidence than males, only a small percentage of the cells were involved, suggesting that this abnormality is most likely a secondary genetic defect that is not important in the pathogenesis of NHL.

Adult↗

PubMed1995

The PML gene encodes a phosphoprotein associated with the nuclear matrix.

The t(15;17)(q22;q12) translocation is the cytogenetic hallmark of acute promyelocytic leukemia (APL). The PML and retinoic acid receptor-alpha (RAR alpha) transcription factor genes are involved at translocation breakpoint. To elucidate the biologic function of PML, antipeptide antibody against PML protein was raised in rabbits. This antibody was able to detect a 90-kD PML protein and a 110-kD PML-RAR alpha fusion protein by Western blotting and a nuclear speckled pattern in all cell lines by immunofluorescent staining. In K562 and NIH/3T3 cells transfected with a PML expression plasmid, we found PML to be associated with the nuclear matrix. Our results also showed that PML is a phosphorprotein. A weak signal was detected in a Western blot containing the immunoprecipitated PML protein using the phosphotyrosine-specific monoclonal antibody. Therefore, at least one of the sites was phosphorylated by a tyrosine kinase. From our analysis of the phosphoamino acids of the PML protein by complete hydrolysis and thin-layer chromatography, we concluded that both tyrosine and serine residues of PML are phosphorylated. To investigate whether expression of the PML protein is cell-cycle related, HeLa cells synchronized at various phases of the cell cycle were analyzed by immunofluorescence staining and confocal microscopy for PML expression. We found that PML was expressed at a lower level in S, G2, and M phases and at a significantly higher level in G1 phase. Our study showed that PML has many similar properties compared with the tumor suppressor, eg, Rb. These findings further support the important role of PML in APL pathogenesis.

3T3 Cells↗

PubMed1995

Decreased expression of the deleted in colorectal carcinoma gene in non-Hodgkin's lymphoma.

The putative tumor suppressor gene deleted in colorectal carcinoma (DCC), located on human chromosome band 18q21, is deleted or inactivated in many solid tumors. Its role in the pathogenesis of non-Hodgkin's lymphoma (NHL) has not been studied. Recently, inactivation of this gene was reported in cases of leukemia with monosomy 18. As monosomy 18 is frequently observed in low-grade NHL, we investigated the incidence of altered DCC gene expression in patients with NHL, and correlated it with the number of copies of chromosome 18. Fifteen unselected cases of NHL were studied for evidence of DCC gene expression by reverse transcriptase-polymerase chain reaction. The results were correlated with Southern blot analysis of the DCC gene and with the number of copies of chromosome 18 determined by fluorescent in situ hybridization (FISH). The controls were tissues from normal colon mucosa and normal tonsils. Eight of 15 (53%) NHL cases lacked DCC mRNA, and one expressed substantially less than normal. Southern blot analysis showed normal configuration of the DCC gene in all samples. Two copies of chromosome 18 were found in 9 of 11 samples studied by FISH: one case had a subpopulation of cells with monosomy 18 and one had trisomy 18. All controls expressed DCC. We conclude that DCC gene expression is frequently absent or decreased in NHL and may be involved in the pathogenesis of NHL. Monosomy 18 was not required for DCC inactivation.

Adult↗

PubMed1995

Cell cycle-related shifts in subcellular localization of BCR: association with mitotic chromosomes and with heterochromatin.

The disruption of the BCR gene and its juxtaposition to and consequent activation of the ABL gene has been implicated as the critical molecular defect in Philadelphia chromosome-positive leukemias. The normal BCR protein is a multifunctional molecule with domains that suggest its participation in phosphokinase and GTP-binding pathways. Taken together with its localization to the cytoplasm of uncycled cells, it is therefore presumed to be involved in cytoplasmic signaling. By performing a double aphidicolin block for cell cycle synchronization, we currently demonstrate that the subcellular localization of BCR shifts from being largely cytoplasmic in interphase cells to being predominantly perichromosomal in mitosis. Furthermore, with the use of immunogold labeling and electron microscopy, association of BCR with DNA, in particular heterochromatin, can be demonstrated even in quiescent cells. Results were similar in cell lines of lymphoid or myeloid origin. These observations suggest a role for BCR in the phosphokinase interactions linked to condensed chromatin, a network previously implicated in cell cycle regulation.

Cell Compartmentation↗

PubMed1995

Epidemiology of influenza A virus infection in patients with acute or chronic leukemia.

Influenza infection is a significant cause of morbidity and mortality in immunocompromised hosts, but its importance in adult cancer patients is largely undescribed. We therefore conducted a prospective study of the incidence and clinical features of influenza infection in patients with acute or chronic leukemia. The cohort, which consisted of all adult leukemia patients undergoing remission-induction chemotherapy during the 1991-1992 influenza epidemic, was followed prospectively for development of signs and symptoms of acute infection of the upper or lower respiratory tract. Of these 294 patients, 111 received chemotherapy as inpatients and 183 as outpatients. Throat swabs and nasal washes for viral culture were obtained from all symptomatic patients, who were then followed until all signs and symptoms resolved. Symptoms of respiratory tract infection developed in 37 leukemia patients (13%). Among these, influenza (A/Beijing/ H3N2) caused 3 (21%) of the 14 infections that developed during hospitalization but only 1 (4%) of the 23 that developed in the community (P = 0.14). Influenza patients presented with fever, rhinorrhea, nasal congestion, headache, and myalgia; those with other infections presented with signs and symptoms of lower respiratory tract infection (productive cough, rales, or rhonchi). Development of pneumonia was common in influenza patients, 1 of whom died from secondary fungal and gram-negative pneumonia. Influenza A virus infections accounted for a substantial portion of acute respiratory infections among adult leukemia patients during a community epidemic. Most infections appeared to be nosocomial and the most likely sources were visitors or hospital personnel. Immunization of household contacts and hospital staff may reduce the risk of influenza infection and its pulmonary complications in leukemia patients.

Acute Disease↗

PubMed1995

Respiratory syncytial virus pneumonia in hospitalized adult patients with leukemia.

Respiratory syncytial virus (RSV) has been demonstrated to be an important cause of life-threatening pneumonia in adult bone marrow transplant recipients; however, its role in other immunocompromised adults has not been defined. We prospectively studied all adult patients with leukemia who were hospitalized at M. D. Anderson Cancer Center (Houston) during a 1-year period (November 1993 through October 1994). During a 19-week period when RSV was prevalent in the community, it was isolated from 9 (10%) of 87 patients with leukemia who developed an acute respiratory illness. In 6 (75%) of 8 patients with profound chemotherapy-induced myelosuppression, the RSV infection was complicated by pneumonia, with an 83% mortality rate. RSV appears to be an important cause of severe and often fatal pneumonia in myelosuppressed patients with leukemia.

Acute Disease↗

PubMed1995

Low incidence of MDR1 expression in acute promyelocytic leukaemia.

The MDR1 gene product, P-glycoprotein, functions as a transmembrane efflux pump for certain cytotoxic agents including anthracyclines. Based upon the clinical observation that patients with acute promyelocytic leukaemia (APL) respond favourably to anthracyclines, we hypothesized that APL cells may have low levels of MDR1 expression. We therefore investigated MDR1 expression in 10 patients with APL and compared results with those obtained in 18 patients with other subtypes of acute myelogenous leukaemia (AML). Prior to reverse transcriptase polymerase chain reaction with MDR1 specific primers, leukaemic cells were purified by fluorescence activated cell sorting to exclude normal haemopoietic cells, in particular lymphocytes, from the MDR1 analysis. In sorted APL cells, MDR1 expression was detected in only two of 10 patients, which was significantly different from findings in other AML subtypes (MDR1 expression in 14/18 patients; P < 0.01). When unsorted specimens from APL patients were studied, five of six cases were MDR1 positive, whereas sorted APL cells were shown to express MDR1 mRNA in only one of these cases. MDR1 mRNA levels expressed as MDR1/beta-2 microglobulin ratios were significantly lower in APL (0.24 +/- 0.2, mean +/- SD) than in AML (0.75 +/- 0.48; P < 0.01). We conclude that low or absent expression of MDR1 in APL cells may contribute to the efficacy of anthracyclines in the treatment of APL.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1995

Transduction of MDR1 into human and mouse haemopoietic progenitor cells: use of rhodamine (Rh123) to determine transduction frequency and in vivo selection.

The MDR1 gene product P-glycoprotein (P-gp) extrudes several anticancer drugs including taxol and fluorescent dyes such as rhodamine (Rh123). Modulation of the level of P-gp expression has the potential of overcoming multidrug resistance. One possible approach is the retroviral transfer of the human MDR1 gene into murine and human bone marrow (BM) progenitor cells. The rationale for this approach is increased chemoprotection, which allows chemotherapy of a greater level of intensity to be delivered. In this study, flow cytometric measurement of Rh123 extrusion was used to test P-gp function in human and mouse haemopoietic progenitor cells, which had been transduced with a virus containing the human MDR1 transcription unit. Human CD34+ selected cells were analysed immediately following transduction. In two successive experiments MDR1 cDNA transduction resulted in a 7% and 11% increase of P-gp expressing Rh123 dull cells. To monitor transduction efficiency over time as well as the possibility of in vivo selection of drug-resistant BM cells in mice treated with increasing numbers of taxol cycles, the assay was also successfully applied to peripheral blood lymphocytes of mice transplanted with MDR1 transduced BM cells, demonstrating increased Rh123 efflux in transduced cells. Analysis of another fluorescence assay using fluorescein di-beta galactopyranoside as a substrate for beta-galactosidase in cells transduced with a MDR1: beta-gal activity. We conclude that the Rh123 efflux assay is a sensitive method to monitor P-gp function in MDR1 cDNA transduced cells, and may be used to enrich transduced cells via flow cytometric cell sorting for Rh123 dull cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1995

Idarubicin cardiotoxicity: a retrospective study in acute myeloid leukemia and myelodysplasia.

PURPOSE: To estimate the incidence of idarubicin (IDA)-related cardiomyopathy in acute myeloid leukemia (AML) and myelodysplasia (MDS). PATIENTS AND METHODS: We analyzed a group of 127 AML/MDS patients who received IDA-based induction and postremission or salvage therapy and achieved a complete remission (CR) that lasted > or = 12 weeks for the development of IDA-related congestive heart failure (CHF). CHF was defined as definite if a resting left ventricular ejection fraction (LVEF) of < or = 45% measured by radionuclide ventriculogram (RV) accompanied the clinical diagnosis of CHF, which had to be made during or within 6 months of receiving IDA and for which no other cause was apparent; without RV confirmation, the diagnosis was considered probable. Patients who had RVs performed were evaluated for decreasing LVEF. Older age (> or = 70 years), prior/sequential anthracycline/mitoxantrone (anthraquinone) therapy, and cardiac disease/hypertension were evaluated as risk factors for the development of CHF. RESULTS: One hundred fifteen patients were assessable (median age, 40 years; median dose, 96 mg/m2). Sixty-five had RVs performed during therapy; 43 had risk factors. The probability of IDA-related cardiomyopathy was 5% at a cumulative IDA dose of 150 to 290 mg/m2, with 18 patients receiving doses greater than 150 mg/m2. At a cumulative IDA dose of 150 mg/m2, the probability of a mild or greater asymptomatic decrease probability of a mild or greater asymptomatic decrease in LVEF (> or = 10% to a level < or = 50%) was 18%, whereas the probability of a moderate or greater asymptomatic decrease in LVEF (> or = 15% to a level < or = 45%) was 7%. No patient with asymptomatic LVEF decreases developed CHF. CHF was more frequent in patients with prior/sequential exposure to anthracyclines/mitoxantrone (P = .01). CONCLUSION: In this patient group, IDA-related cardiomyopathy was uncommon with cumulative IDA doses of up to 290 mg/m2. Asymptomatic LVEF decreases were more frequent, but their predictive value for the development of CHF is unclear.

Adolescent↗

PubMed1995

Growth-factor stimulation reveals two mechanisms of retinoblastoma gene inactivation in human myelogenous leukemia cells.

Mutation or deletion of the retinoblastoma tumor suppressor gene (Rb) or abnormal Rb protein expression is found in many types of human solid tumors. Low or absent levels of Rb protein are usually found in the leukemic cells of patients with acute myelogenous leukemia (AML) who have an extremely poor prognosis. The absence of Rb protein in these AML cells could result from defects in the Rb gene or from abnormal cell cycle regulation that affects Rb expression. To test these possibilities and to examine whether a low level of Rb protein in AML cells could be up-regulated, we studied the effect that growth factors interleukin 3 (IL3) and granulocyte-macrophage colony stimulating factor (GM-CSF) had on the levels of Rb protein and Rb phosphorylation in AML cells from patients with low Rb or no Rb protein expression. We observed three responses to growth factor-stimulation in leukemic cells taken from patients with AML: (1) some AML cell samples entered a proliferative phase, and Rb protein levels increased with the appearance of normally phosphorylated forms of Rb protein and positive nuclear staining for Rb protein; (2) some AML cell samples became more proliferative, but the levels of Rb protein remained low or absent; and (3) some AML cell samples showed no response. These results indicate that at least two different mechanisms may be responsible for the lack of Rb protein in the leukemic cells of some patients with AML.

Gene Expression Regulation, Leukemic↗

PubMed1995

Expression of MDR1 by normal bone marrow cells and its implication for leukemic hematopoiesis.

Expression of MDR1 is a well-characterized mechanism leading to resistance of tumor cells to drugs like vinca-alkaloids, anthracyclines, and epipodophyllotoxins. In hematopoiesis, recent data indicate that not only leukemic cells, but also some populations of normal hematopoietic cells, particularly CD34+ progenitor cells as well as peripheral blood lymphocytes, express a functional multidrug-resistant phenotype. Among CD34+ cells, we found evidence that myeloid committed precursor cells (CD34+/CD33+) have lower levels of MDR1 expression than earlier CD34+ cell populations, but there was no difference in MDR1 expression between CD34+/HLA-DR- and CD34+/HLA-DR+ subpopulations. During normal myeloid differentiation, MDR1 expression is down-regulated, which is similar to our observations in acute myelogenous leukemia (AML): MDR1 expression was only rarely detected in acute promyelocytic leukemia, which was in contrast to other subtypes of AML; also, within leukemic subpopulations of the same patient, higher MDR1 levels were correlated with a more immature immunophenotype. Regarding regulation of MDR1 expression, we did not observe changes of MDR1 expression in normal CD34+ cells in response to various cytokines. However, in 2 patients with AML treated with interleukin-3 and granulocyte-colony stimulating factor, respectively, a significant down-regulation of MDR1 expression was found after 24 hours. In conclusion, there is evidence that the pattern of MDR1 expression observed in leukemias reflects the distribution of MDR1 in normal hematopoiesis. In contrast to normal CD34+ cells, leukemic cells from some AML patients can respond to cytokines with a down-regulation of MDR1, which may contribute to response to cytokine/chemotherapy combinations.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1995

Quantitative expression of proliferating cell nuclear antigen by western blot (PCNAWB) in peripheral blasts correlates with remission induction in patients with acute myelogenous leukemia.

Proliferating cell nuclear antigen (PCNA) is a 36-kD nuclear protein that functions as a cofactor of delta DNA polymerase which is regulated in a cell cycle-dependent fashion. PCNA expression also increases when cells are actively engaged in DNA repair. We used Western blotting (WB) to measure the level of expression of PCNA in peripheral blasts of 36 adult acute myelogenous leukemia (AML) patients treated with Ara-C based induction regimens. PCNA levels correlated positively with the percentage of cells in S+G2M of the cell cycle. Logistic regression analysis revealed PCNA (beta = 4.5162; p = 0.0260) together with age (beta = 0.1777; p = 0.0364) as independent variables for remission induction: high PCNA levels were associated with poor response to induction therapy. PCNA expression was not, however, a predictor of survival in this subset of patients. We conclude that PCNA levels in this disease may be important for predicting response to Ara-C based remission induction chemotherapy.

Adult↗

PubMed1995

A pilot study of the biologic and therapeutic effects of granulocyte colony-stimulating factor (filgrastim) in patients with acute myelogenous leukemia.

In a carefully monitored pilot study, the in vivo biologic effects of filgrastim were investigated in eight patients with relapsed/refractory acute myelogenous leukemia. Within each patient, filgrastim was administered as a single agent prior to any chemotherapy in escalating doses of 0.12-6.0 micrograms/kg/day as a continuous intravenous infusion. The dose was increased every 14 days until an ANC of > or = 2500/mm3 had been achieved or there was evidence of proliferation of the leukemia. In patients who demonstrated growth of the leukemic clone, cytosine arabinoside was initiated at 200 mg/m2/day for 5 days. Through-out the course of therapy, the effects of filgrastim on maturation and proliferation were assessed by in vitro studies of bone marrow aspirates. Three patients demonstrated a sustained increase in ANC; one achieved a partial remission and remained on therapy for 31 weeks. Two of the three responding patients had hypocellular marrows at the time of initiating filgrastim and demonstrated a low but normal pattern of growth in CFU-GM assay early in the treatment course. This suggested that these two characteristics may define an environment in which filgrastim can induce a growth advantage for the normal residual hematopoietic elements. In this study of selected patients, filgrastim appeared safe.

Adult↗

PubMed1995

Chemotherapy resistance to taxol in clonogenic progenitor cells following transduction of CD34 selected marrow and peripheral blood cells with a retrovirus that contains the MDR-1 chemotherapy resistance gene.

A retrovirus containing the multiple drug resistance (MDR-1) cDNA, was used to transduce cultures of CD34 selected human marrow cells, on stromal monolayers in the presence of hematopoietic growth factors IL-3 and IL-6, following collection from patients recently recovered from chemotherapy-induced myelosuppression. In one experiment, these CD34 selected cells were grown in Dexter cultures for 35 days or more following MDR-1 transduction, and then plated in methylcellulose. Polymerase chain reaction (PCR) analysis of colonies picked after 10-14 days of methylcellulose culture, using a set of primers that are specific for the endogenous or the retrovirally transduced MDR-1, showed that the long-term culture initiating cells (LTCICs) were transduced by the MDR-1 virus. Analysis of the colonies from the CD34 selected MDR-1 transduced cells, with a reverse transcription (RT) PCR assay that could distinguish viral MDR-1 mRNA from endogenous MDR-1 mRNA, showed that the viral MDR-1 mRNA levels were much higher than that of the MDR-1 mRNA from the endogenous MDR-1 gene in the transduced CD34 selected cells. Fluorescence activated cell sorting (FACS) analysis of the CD34 selected transduced marrow cells within 48 h after the transduction, using the C219 and UIC2 monoclonal antibodies for p-glycoprotein, showed that the transduction frequency under these conditions varied from 7 to 20%. Rhodamine efflux studies showed that this additional p-glycoprotein was functional and that the frequency of cells with high p-glycoprotein levels was higher in the transduced cells than in the non-transduced cells. The resistance to taxol of the CD34 selected transduced cells, as judged by the plating efficiency of clonogenic progenitor cells derived from these cells by growth in methylcellulose supplemented with taxol was much higher in the transduced cells than in untransduced cells. In order to test the reproducibility of the transduction frequency of the retroviral supernatants from PA317 MDR-1 viral producer cells on CD34 selected cells, the virus produced from 12 different lots of supernatants from the PA317 MDR-1 producer cell line was used to transduce CD34 selected marrow cells from four different patients, and to transduce the peripheral blood cells of two additional patients collected following chemotherapy-induced myelosuppression. The supernatant lots used for these transduction experiments were tested by Microbiological Associates (Rockville, MD, USA), by the Mus dunni co-cultivation and amplification tests in the S+L-assay and found to be negative for replication-competent retrovirus, and later approved for human use by the Food and Drug Administration.(ABSTRACT TRUNCATED AT 400 WORDS)

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1995

Analysis of CD7 expression in acute myelogenous leukemia: martingale residual plots combined with 'optimal' cutpoint analysis reveals absence of prognostic significance.

Conflicting results exist regarding the prognostic importance of CD7 expression in acute myelogenous leukemia (AML). Differences in the method of determining CD7 positivity, the antibody used, the therapy administered, and the CD7 level used as a cutoff point to reduce it to a binary variable have all been postulated to account for the discordant findings. We determined the level of CD7 expression by flow cytometric analysis using the Leu9 monoclonal antibody in 331 patients with newly diagnosed AML and attempted to determine the impact of CD7 on AML prognosis. This study used the same methodology and antibody as three of the four studies that reported a positive association between CD7 expression and prognosis in AML. Optimal cutpoint analysis was used to divide the population into CD7-positive (CD7+) (>10.5% expression) and CD7-negative (CD7-) (< 10.5% expression) groups with the largest survival difference. At the optimal cutpoint, the difference in survival was not statistically significantly different (P = 0.068 uncorrected, P = 0.244 corrected for optimal cutpoint search). There was a marked imbalance in the distribution of favorable cytogenetic abnormalities [t(8;21), inversion 16, t(15;17)], with 95% segregating to the CD7- group. Analysis excluding patients with favorable cytogenetic abnormalities revealed no prognostic importance for CD7 expression (P = 0.24 uncorrected). The response rate (CR) and survival experiences of CD7+ and CD7- patients were similar with six different regimens. CD7 expression was not a significant independent prognostic factor in a Cox regression model that included cytogenetics as a predictive variable, but it was marginally significant when cytogenetics was excluded. We conclude that regardless of the antibody used, the therapy received, or the cutoff point selected to determine CD7 expression, CD7 is not associated with response rate, prognosis, or survival in AML. The 'optimal cutoff point analysis' utilized in this study has applicability to other biologic parameters as well.

Adolescent↗

PubMed1995

Fludarabine plus doxorubicin in previously treated chronic lymphocytic leukemia.

Based on the activity of fludarabine and doxorubicin in chronic lymphocytic leukemia (CLL), 30 patients received this combination. The median age of these patients was 61 years; median Zubrod performance status was one; median number of prior therapies was three; and median time to treatment was 53 months. Rai stage was 0 for two patients, I/II for 19 patients, and III/IV for nine patients. Prior treatment included fludarabine in 25 patients. In this regimen, fludarabine was administered as 30 mg/m2/d IV x 3 to 10 patients, 25 mg/m2/d IV x 4 to three patients, and to 17 patients as 30 mg/m2/d IV x 4. A 50 mg/m2 IV dose of doxorubicin was given to all patients. The first 17 patients received prednisone 30 mg/m2 x 5 days; however, this was discontinued due to other data demonstrating no therapeutic advantage and increased opportunistic infections when corticosteroids were added to fludarabine. Toxicity consisted primarily of infectious episodes: pneumonia nine, bacteremia one, FUO seven, and minor infection five. Two deaths from pneumonia occurred. Standard guidelines for response were used with the addition of a nodular CR group. Despite prior treatment with fludarabine in the majority of patients, the response rate in the 29 evaluable patients was CR 3%, nodular CR 17%, PR 35%, fail 38% and early death 7%. This combination of fludarabine and doxorubicin is active against CLL and warrants further study.

Antineoplastic Combined Chemotherapy Protocols↗