To assess and compare the effects of mutant MYH9 alleles in MDA-MB-231 and HeLa cultured cell lines.
Methods
The phenotypes of MDA-MB-231 and HeLa cells were studied after transient transfection with two MYH9 dominant mutant alleles, MYH9-R702C and MYH9-R705H which are linked to syndromic and nonsyndromic hearing loss respectively. Expression of the exogenous gene product was detected with fluorescence-tagged GFP. In both cultured cell lines, transfection efficiency was greater than 95%. Actin filaments were visualized by incubation with rhodamine-phalloidin and cell nuclei were marked with DAPI nucleic acid stain.
Results
MDA-MB-231 cells transfected with MYH9-R705H were found to have a longer cell shape and increased actin cytoskeleton disarray than the wild type and MYH9-R702C mutant. Cell morphology and actin cytoskeletal configuration of MYH9-R702C transfected cells were similar to that of wild type MYH9. The cell morphology of HeLa cells transfected with MYH9 mutant alleles were similar to that of wild type MYH9.
Conclusions
The in vitro dysfunction detected within the MDA-MB-231 cell line may provide a first step towards deciphering the pathogenic mechanisms by which MYH9 mutants cause hearing loss.
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