ABSTRACT
<p><b>OBJECTIVE</b>To analyze the cloning result of CD40 mutant from RPMI8226 cells, a multiple myeloma (MM) cell line, and study the change of the expressions of costimulatory molecules and the apoptosis of RPMI8226 cells after activated with CD40.</p><p><b>METHODS</b>CD40 gene mutant in RPMI8226 cell was detected by RT-PCR and DNA sequencing. The cell lines were cultured with sCD40L, L929/CD40L, soluble 5C11 (an anti-CD40 mAb) plate-bound 5C11 and their respective controls. Their growth curves, change of phenotypes and cell cycles were detected. The signalosome of CD40 on RPMI8226 cells were analyzed with laser scanning confocal microscope.</p><p><b>RESULTS</b>There was a single base substitution (TCA-->TTA) in the open reading frame of CD40 from RPMI8226 cells, resulting in the conversion of a amino acid (Ser124Leu). Only plate-bound antibody could inhibit RPMI8226 cell proliferation [(2.5 +/- 0.6) x 10(5) vs (7.8 +/- 1.2) x 10(5), P <0.05] and cause G1 arrested [(58.0 +/- 3.6)% vs (42.0 +/- 2.3)%, P <0.05]. muCD40 was translocated to CD40 signalosome while CD40 activated.</p><p><b>CONCLUSION</b>The mutated CD40 in RPMI8226 cell might decrease its affinity to CD40L, leading to the disorder of CD40 signal.</p>
Subject(s)
Humans , Antibodies, Monoclonal , Pharmacology , CD40 Antigens , Genetics , Allergy and Immunology , CD40 Ligand , Genetics , Pharmacology , Cell Cycle , Cell Line, Tumor , Cell Proliferation , DNA Mutational Analysis , Multiple Myeloma , Genetics , Pathology , Mutation , Phenotype , TransgenesABSTRACT
<p><b>OBJECTIVE</b>To clarify the patients' pathogenic mechanism in an achondroplasia family not according with the genetic law of autosomal dominant inheritance disease at gene level.</p><p><b>METHODS</b>Genomic DNA from peripheral blood of all members in this family was used for amplification of the exon 10 of fibroblast growth factor receptor 3(FGFR3) gene by PCR; mutation was detected by DNA sequencing and identified by restriction endonuclease MaeIII.</p><p><b>RESULTS</b>A new mutation of A to T at nucleotide 1180 was found in patients but not in unaffected members.</p><p><b>CONCLUSION</b>Combined with pedigree analysis, it was summarized that achondroplasia patients in this family might result from this new mutation.</p>