Carlos Bachier - Academia.edu (original) (raw)

Papers by Carlos Bachier

Oncogene, 1999

In order to test if the carboxyl terminal polypeptide of the Retinoblastoma (Rb) tumor suppressor... more In order to test if the carboxyl terminal polypeptide of the Retinoblastoma (Rb) tumor suppressor protein, could be used to suppress the growth factor-independent growth phenotype of p210 bcr-abl positive myeloid cells, we introduced a truncated form of the 3' end of the Rb cDNA encoding its last 173 amino acid residues (Rb Cbox) which localize into the cytoplasm where the p210 bcr-abl transforming protein is found, into myeloid cells (32D) which depends on the p210 bcr-abl protein for IL3 growth factor-independent growth (32D-p210). The expression of the plasmid vectors carrying the Rb C-box cDNAs was shown to inhibit the abl tyrosine speci®c protein kinase activity of the p210 bcr-abl oncoprotein and to suppress the IL3-independent growth phenotype of the 32D-p210 cells. The Rb C-box polypeptides did not suppress the growth of the untransfected 32D parental cell line in methylcellulose in the presence of IL3conditioned medium. These results suggest that the cytoplasmic localization of the p210 bcr-abl allows it to escape the eect of intranuclear proteins such as Rb which negatively regulate the p145 c-abl kinase.

Oncogene, 1998

We ®rst showed that the introduction of a bcr ± abl transcription unit into the 32D murine myeloi... more We ®rst showed that the introduction of a bcr ± abl transcription unit into the 32D murine myeloid cell line (P210bcrabl32D) converts this cell line from an IL3 dependent cell line to an IL3 growth independent cell line. We next cloned a fragment of the bcr ± abl cDNA, which codes for the bcr oligomerization domain and neighboring regions. To test for a transformation inhibitory eect of this oligomerization inhibitory peptide transcription unit on the p210 bcr ± abl mediated IL3 independent growth of the P210bcrabl32D cell line, we transiently co-electroporated into the growth factor dependent 32D cells, mixtures of plasmids which contained varying ratios of the plasmid expression vectors for the bcr oligomerization inhibitory peptide along with a smaller amount of the plasmid expression vector for the full length p210 bcr ± abl . (The P210 bcr ± abl protein converts the 32D from a growth factor dependent into a growth factor independent cell line.) We then showed that the oligomerization domain containing fragment from the bcr and bcr ± abl proteins, can be used to inhibit the IL3 independent growth of p210 bcr ± abl positive 32D cells. These studies may be of eventual interest for those investigators whose goal is to design molecular therapeutic approaches to CML based on the use of peptidomimetic chemical functionalities, which mimic the structure and the inhibitory binding properties of the oligomerization domain containing fragment so as to inhibit the transforming function of the P210 bcr ± abl oncoprotein.

$Research paper thumbnail of Paclitaxel plus high-dose cyclosphosphamide with G-CSF support in patients with relapsed and refractory aggressive non-Hodgkin's lymphoma$

British Journal of Haematology, 1998

Based on the single-agent activity of both paclitaxel and cyclophosphamide in the treatment of no... more Based on the single-agent activity of both paclitaxel and cyclophosphamide in the treatment of non-Hodgkin's lymphoma (NHL), we conducted a phase II study to evaluate the efficacy of the combination of the two drugs in patients with refractory and relapsed aggressive NHL. All patients received 900 mg/m 2 bolus of cyclophosphamide intravenously daily for 3 consecutive days with a concurrent infusion of 150 mg/m 2 of paclitaxel over 72 h (50 mg/m 2 /d). 24 h after the completion of chemotherapy, patients received subcutaneous injections of 5 mg/kg of granulocyte-colony stimulating factor (G-CSF) daily until white cell count recovery. Treatment was repeated every 3 weeks. Patients who had at least a partial response (PR) after two courses continued to receive a maximum of four courses. Patients with responding disease were allowed to undergo high-dose chemotherapy followed by stem-cell/bone marrow transplantation if they were eligible. Of the 77 patients who were eligible for the study, 74 (96%) were evaluable for toxicity and treatment response. The overall response rate was 45% (95% CI 33-57%). Patients who received treatment after their disease relapsed from a complete response (CR) had an 81% response rate (38% CRs), whereas those with primary refractory disease had a 22% response rate. Toxicities of >grade 2 included alopecia (100%) and stomatitis (25%). Neutropenic fever of grade >2 occurred after 18% of the courses, and platelet count of р20 × 10 9 /l developed after 20% of the courses. Thus, the combination of paclitaxel plus high-dose cyclophosphamide is an effective new regimen in the treatment of refractory and relapsed NHL.

British Journal of Haematology, 1997

In order to determine the activity of paclitaxel in patients with relapsed or refractory non-Hodg... more In order to determine the activity of paclitaxel in patients with relapsed or refractory non-Hodgkin's lymphoma (NHL), we conducted a phase II clinical trial in which eligible patients received paclitaxel 200 mg/m 2 intravenously over 3 h. Treatment was repeated every 3 weeks. Patients achieving complete or partial responses after two courses of paclitaxel continued to receive therapy for a maximum of eight courses, otherwise they were removed from the study. Of 96 evaluable patients, 45 (47%) had primary refractory disease, and 51 (53%) had relapsed lymphoma. The median number of prior treatment regimens was two (range one to 10 regimens). 45 patients had lowgrade, 44 had intermediate-grade, and seven had mantle cell lymphoma. 24/96 patients responded (10 complete and 14 partial remissions) for an overall response rate of 25% (95% CI 17-35%). Patients with relapsed lymphoma had a higher response rate than those with primary refractory disease (19/51=37% v 5/45=11%; P<0 . 01), and patients with relapsed intermediate-grade lymphoma had a higher response than those with relapsed low-grade lymphoma (9/18=50% v 10/31=32%; P = 0 . 22). The treatment was very well tolerated with the most common side-effects being alopecia (100%), peripheral neuropathy (35% of у grade II), and arthralgia/myalgia (25% of у grade II). After the first course of paclitaxel, grade III/IV thrombocytopenia and neutropenia were observed in 21% and 23% of the patients respectively. 23 episodes of neutropenic fever developed after 250 courses of paclitaxel therapy (8%). We conclude that paclitaxel, at this dose and schedule, is an active new drug for the treatment of non-Hodgkin's lymphoma. The activity of paclitaxel combination programmes are currently under investigation.

Science) delivered the keynote speech. Forty-eight posters were presented during the event; of th... more Science) delivered the keynote speech. Forty-eight posters were presented during the event; of these, forty-four were entered into the competition.

Stem Cells, 2006

Dendritic cells (DCs) are effective antigen-presenting cells. We hypothesized that increasing the... more Dendritic cells (DCs) are effective antigen-presenting cells. We hypothesized that increasing the DC populations in donor lymphocyte infusions (DLIs) may augment the graft versus malignancy effect, particularly if granulocyte-macrophage colony-stimulating factor (GM-CSF) mobilization resulted in increased precursor dendritic cell (pDC) 1 cells. Mature DCs, pDC1 cells, pDC2 cells, and CD34+ cells from the same donor were compared after granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood stem cell collections and GM-CSF mobilized DLI collections. Mobilization with G-CSF resulted in up to a 10-fold larger number of CD34+ cells per kg and a 3–5-fold larger number of mature DCs, pDC1 cells, and pDC2 cells within the same donor compared with GM-CSF. The ratio of pDC1 to pDC2 in each donor remained constant with either cytokine. In this small sample of normal donors, it appears that G-CSF mobilizes more CD34+ cells, mature DCs, pDC1 cells, and pDC2 cells within the same donor than does GM-CSF, with no significant polarization by G-CSF or GM-CSF for either pDC1 or pDC2 cells.

Biology of Blood and Marrow Transplantation, 2005

Acute graft-versus-host disease (aGVHD) is partly mediated through activated T cells, and these c... more Acute graft-versus-host disease (aGVHD) is partly mediated through activated T cells, and these cells are known to express the high-affinity receptor for interleukin 2 (IL-2R). Denileukin diftitox is composed of human IL-2 and diphtheria toxin that is cytotoxic to activated lymphocytes expressing the high-affinity IL-2R. We describe the results of a phase II study of denileukin diftitox in 22 patients with steroid-resistant aGVHD. Twenty patients were treated at dose level 1 (4.5 μg/kg daily on days 1–5 and then weekly on study days 8, 15, 22, and 29), and 2 patients were treated at dose level 2 (9.0 μg/kg delivered on the same schedule). Dose level 2 was associated with grade 3/4 renal and hepatic toxicity and vascular leak syndrome, and no further patients were treated at this level. Dose level 1 was generally well tolerated. The response of aGVHD was assessed at study days 36 and 100. Nine patients (41%) responded, all with a complete response at study day 36, and 6 patients (27%) responded at study day 100 (4 complete responses and 2 partial responses). Denileukin diftitox has promising activity in steroid-resistant aGVHD, and further study is warranted.

Biology of Blood and Marrow Transplantation, 2009

Currently, no agents are approved by the United States Food and Drug Administration for either pr... more Currently, no agents are approved by the United States Food and Drug Administration for either prevention or treatment of acute graft-versus-host disease (GVHD). Since the field lacks formal precedents establishing a comparative basis for assessing the efficacy and safety of new investigational agents, the design of trials to demonstrate overall clinical benefit with statistical certainty remains extremely difficult both for academic and industry sponsors. As a step toward addressing this problem, a panel of experts met on two occasions to reach consensus on recommendations for terminology defining a clinically meaningful primary endpoint in studies assessing treatment for acute GVHD. The panel recommended terminology for "very good partial response" that includes both diagnostic and functional criteria. Assessment of response at day 28 after starting treatment is appropriate for the primary end point, but later time points can be considered. Since treatment agents can be designed for use on a single occasion, on repeated

Experimental Hematology, 1999

The use of hematopoietic growth factors, stromal monolayers, and frequent medium exchange allows ... more The use of hematopoietic growth factors, stromal monolayers, and frequent medium exchange allows the expansion of hematopoietic progenitors ex-vivo. We evaluated the use of ex-vivo expanded progenitor cells for hematopoietic reconstitution following high dose chemotherapy (HDC) in breast cancer patients. Patients with high-risk Stage II or metastatic breast carcinoma underwent bone marrow aspirations using general anesthesia. A total of 675–1125 × 106 mononuclear cells (MNC) were seeded for ex-vivo expansion for 12 days in controlled perfusion bioreactors (Aastrom Biosciences, Inc.). The bone marrow cultures, which included the stromal cells collected with the aspirate, were supplemented with erythropoietin, granulocyte-macrophage-colony stimulating factor (GM-CSF)/IL-3 fusion protein (PIXY 321), and flt3 ligand. Stem cell transplant was performed with expanded cells after HDC. A median bone marrow volume of 52.9 mL (range 42–187 mL) was needed to inoculate the bioreactors. Median fold expansion of nucleated cells (NC) and colony forming unit granulocyte-macrophage (CFU-GM) was 4.9 and 9.5, respectively. The median fold expansion of CD34+lin−and long-term culture–initiating culture (LTC-IC) was 0.42 and 0.32, respectively. Five patients were transplanted with ex-vivo expanded NC. Median days to an absolute neutrophil count > 500/μL was 18 (range 15–22). Median days to a platelet count > 20,000/μl was 23 (range 19–39). All patients had sustained engraftment of both neutrophils and platelets. Immune reconstitution was similar to that seen after HDC and conventional stem cell transplantation. We conclude that ex-vivo expansion of progenitor cells from perfusion cultures of small volume bone marrow aspirates, allows hematopoietic reconstitution after HDC.

Journal of Hematotherapy & Stem Cell Research, 2001

The feasibility of using ex vivo-expanded hematopoietic progenitor cells to reconstitute hematopo... more The feasibility of using ex vivo-expanded hematopoietic progenitor cells to reconstitute hematopoiesis after high-dose chemotherapy is presently being examined. Early studies have shown that myeloid and erythroid hematopoiesis can be successfully reconstituted after high-dose chemotherapy and ex vivo-expanded hematopoietic cell transplantation. The lymphoid reconstitution, however, has not been addressed previously. In this study, we examined the diversity of the T cell receptor V beta chain (TCRBV) repertoires in 5 breast cancer patients who were transplanted with ex vivo-expanded bone marrow mononuclear cells as the only source of hematopoietic graft. Using the TCRBV third complementarity determining region (CDR3) fingerprinting methodology, it is shown that CD4(+) and CD8(+) T cell subsets after ex vivo-expanded hematopoietic cell graft transplants exhibit TCRBV diversities that are similar in complexity when compared to those seen after conventional autologous peripheral blood stem cell transplants (PBSCT). No apparent difference in the extent of CDR3 diversity was found between ex vivo expanded and conventional autologous PBSCT recipients when the CD4(+) and CD8(+) subsets were further separated into CD45RA(+) "naïve" and CD45RO(+) "memory" subsets. The diversity of the CD45RA(+) naïve subsets was as complex as that of the CD45RO(+) memory subsets. These results indicate that T cell repertoire diversification is not further compromised when ex vivo-expanded hematopoietic cells are used instead of autologous peripheral blood stem cells as the only source of graft.