In this report, we have measured the formation and repair of cisplatin induced DNA adducts in the dihydrofolate reductase (DHFR) and ribosomal RNA (rRNA) genes in three cell lines: normal human fibroblasts, Fanconi's anemia complementation group A (FAA) and Xeroderma pigmentosum complementation group A (XPA).
These two different assays confirmed that our retroviral vectors were capable of transferring a functional FACC gene to lymphoid cell lines established from FA(C) patients.
We demonstrated efficient transduction, expression, and phenotypic correction in lymphoblastoid cell lines derived from FA (C) patients using a recombinant adeno-associated virus (rAAV) vector containing the FACC gene.
Abnormal lymphokine production: a novel feature of the genetic disease Fanconi anemia. II. In vitro and in vivo spontaneous overproduction of tumor necrosis factor alpha.
Treatment of FA cells with IL-6, which partially restored an almost normal sensitivity to MMC of FA cells also reduces the TNF alpha overproduction in FA lymphoblasts.
FA lymphoblasts had a normal sensitivity to the cytostatic effect of hyperoxia, while in both control and FA lymphoblasts FAC mRNA levels were unaffected by oxygen.
The therapeutic potential of this system was established by stably transducing B-lymphoblastoid cells from a Fanconi anaemia group C (FA-C) patient with a mini-EBV constitutively expressing the normal FACC cDNA and showing in vitro correction of the FA phenotype.
As the p53 tumor suppressor gene encodes a transcriptional activator whose targets include genes that regulate genomic stability, cellular response to DNA damage and cell cycle progression, we suggest that altered expression of p53 may be relevant to the FA phenotype.
We have previously demonstrated efficient retroviral-mediated gene transduction and correction of FA(C) cell lines and peripheral blood-derived CD34+ progenitors from patients carrying mutant FACC alleles.
For FA(C) hematopoietic cell infection, vector supernatant transduction in the presence of recombinant human IL-3, IL-6, and SCF was found to be superior to transduction supported by autologous FA(C) patient stroma.
For FA(C) hematopoietic cell infection, vector supernatant transduction in the presence of recombinant human IL-3, IL-6, and SCF was found to be superior to transduction supported by autologous FA(C) patient stroma.
For FA(C) hematopoietic cell infection, vector supernatant transduction in the presence of recombinant human IL-3, IL-6, and SCF was found to be superior to transduction supported by autologous FA(C) patient stroma.
Chromosome analyses were performed on lymphocytes from seven patients with MEN 1, four healthy first-degree relatives (three of whom were children), six phenotypically normal volunteers, and three patients with Fanconi's anemia.
Expression of FACC gamma 1 in FACC-deficient Fanconi anemia (FA) lymphoblasts corrected the hypersensitivity of these cells to mitomycin C. Binding of FACC gamma 1 to protein A-agarose and incubation with radiolabeled cell lysates identified three polypeptides with molecular masses of 65, 50, and 35 kDa that were also detected on immunoblots probed with the purified FACC gamma 1 polypeptide.
Restriction site assays were established for all 8 pathogenic mutations identified in the FAC gene to date and used to screen a total of 94 unrelated FA patients.
To address this possibility, nonadherent low density T-lymphocyte depleted (NALT-) cells from fresh or cryopreserved cord blood were sorted for CD34 phenotype, transduced with a recombinant retroviral vector encoding Fanconi anemia complementation C (FACC) gene, and cells expanded ex vivo in suspension culture for 7 days with growth factors.
A known mutant allele of FAC resulting from the substitution of Pro for Leu at codon 554 fails to correct the sensitivity of FA group C cells to mitomycin C. We reasoned that overexpression of the mutant protein in a wild-type cellular background might induce the FA phenotype by competing with endogenous FAC for binding to the accessory proteins.
Both the cross-linking defect and the enhanced cytotoxicity of cross-linkers on Fanconi anemia group C cells are corrected completely by cytoplasmic isoforms of the FAC protein, but not by an isoform targeted to the nucleus.