Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.6 (chymopapain)
 407 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Expression of antigens coexpressed on cord blood (CB) CD34+ cells was evaluated by flow cytometry analysis and reverse transcriptase polymerase chain reaction (RT-PCR). Antigen expression was also comparatively analyzed by flow cytometry and limiting dilution (LD) RT-PCR to investigate effects of chymopapain on epitopes of several cell surface markers: LD RT-PCR allows detection of the expression of antigens degraded by chymopapain which are not identified by flow cytometry. Monoclonal antibodies (MoAbs) that recognize chymopapain resistant epitopes on several coexpressed cell surface markers were identified: these included MoAbs directed against CD11a, CD13, CD18, CD38, CD45RO, CD51, HLA-DR, Thy-1, c-kit, flt-3 (STK-1), and mdr-1. Interestingly, chymopapain treatment caused enhanced staining with MoAbs against HLA-DR, Thy-1, flt-3, mdr-1, and CD51. The frequency (LD RT-PCR) of CD18, CD38, Thy-1, and c-kit RT-PCR signals on pure sorted CD34+ CD18-, CD34+ CD38-, CD34+ Thy-1-, and CD34+ c-kit- cells, respectively, was similar in corresponding subsets treated or not with chymopapain. In contrast, the frequency of CD33 RT-PCR signals on sorted CD34+ CD33- cells was higher in chymopapain-treated samples than in untreated samples and thus confirmed at the transcriptional level that the epitope recognized by anti-CD33 is chymopapain sensitive. Our findings extend data on the phenotypic profile of CB CD34+ cells and show that several key cell surface markers of hematopoietic progenitor cells are chymopapain resistant. In addition, the results of the present study demonstrate that the RT-PCR can be applied to the analysis of multiple RNA species in small numbers of hematopoietic progenitor cells and show that LD RT-PCR allows the identification and frequency determination of rare cells which are undetectable by flow cytometry.
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PMID:Surface antigen expression on CD34+ cord blood cells: comparative analysis by flow cytometry and limiting dilution (LD) RT-PCR of chymopapain-treated or untreated cells. 887 54

Contamination of transplants with tumour cells may contribute to relapse after peripheral blood stem cell transplantation (PBSCT). We studied the feasibility of CD34+ cell selection from blood-derived autografts obtained following G-CSF-supported cytotoxic chemotherapy in a group of 25 patients with breast cancer (10 with high-risk stage II/III and 15 with stage IV without bone or bone marrow involvement). Using immunomagnetic beads (Isolex 300 SA. Baxter) CD34+ cells were enriched and released by chymopapain resulting in a median purity of 95% (range 82-99%) and a median recovery of 80% (range 27-132%). The enrichment procedure did not change the proportion of CD34+ subsets coexpressing HLA-DR, CD38 and Thy-1, while L-selectin was removed from the cell surface following selection. Using a sensitive immunocytological technique with a cocktail of epithelial-specific antibodies (anti-cytokeratin 8, 18 and 19; HEA125; BM7 and BM8), five leukaphereses products contained epithelial cells, whereas the selected CD34+ cell fraction was free of tumour cells. A neutrophil count of 0.5 x 10(9)/l and a platelet count of 20 x 10(9)/l was reached after a median time of 14 and 10d following 40 high-dose chemotherapy (HDC) cycles. Our results indicate that immunomagnetic selection of CD34+ cells yields highly purified autografts devoid of tumour cells whereas the engraftment ability of the progenitor and stem cells is fully retained.
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PMID:Immunomagnetic selection of CD34+ peripheral blood stem cells for autografting in patients with breast cancer. 921 92

The efficacy of an immunomagnetic purging method and the Isolex 300 devices were assessed for selecting CD34+ cells from leukapheresis products of 29 patients with non-Hodgkin's lymphoma (NHL), 39 with multiple myeloma and 34 with breast cancer. The mean purity of the CD34+ cell population was 93.6% and the mean recovery was 67.7%. Following enzymatic cleavage by chymopapain the expression of Thy-1 and Leu-8 was significantly reduced without affecting haematological recovery. The population of selected CD34+ cells of 4/8 patients with follicular lymphoma became PCR-negative. A 2.5 log reduction of tumour cells could be achieved in four patients with multiple myeloma as shown by a quantitative PCR assay. There were no tumour cells detectable in any of the 19 CD34+ cell preparations of patients with breast cancer. In 64 patients who received 94 cycles of high-dose therapy, a mean number of 4.7x 10(6) CD34+ cells/kg were autografted. The time needed for platelet reconstitution was different when a comparison was made with 156 patients, who had received unmanipulated leukapheresis products (10 v 12 d, P = 0.006). No significant differences with regard to neutrophil recovery were noted. Five patients had a graft failure. Two of them died (on day 78 and 88 following PBSCT), and three patients were rescued with unmanipulated back-up transplants. In conclusion, the immunomagnetic selection of CD34+ cells provides autografts with reduced tumour cell content and an engraftment ability similar to that of unmanipulated autografts.
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PMID:Autografting with CD34+ peripheral blood stem cells: retained engraftment capability and reduced tumour cell content. 1005 Jul 23