Characterization of AMC-HN-9, a cell line established from an undifferentiated carcinoma of the parotid gland: Expression of alpha 6 beta 4 with the absence of BP180 and 230

We recently reported the development of a cell line, AMC-HN-9, established from an undifferentiated carcinoma (UDC) of the parotid gland. AMC-HN-9 con sists mostly of spindle-shaped cells, has poor in vitro adhesiveness and an in vitro appearance that is different from that of other epithelial cell l ines. To test the hypothesis that structural or functional abnormalities of the hemidesmosomes might contribute to the morphological appearance and bi ology of UDCs, we studied the expression of hemidesmosomal proteins in AMC- HN-9. Flow cytometry, indirect immunofluorescence, immunoprecipitation, rev erse transcriptase-polymerase chain reaction, and cytogenetic analysis were used. AMC-HN-9 cells express the alpha 6 and beta 4 integrin subunits at n early the same intensity as head and neck squamous cell carcinoma cell line s. However, AMC-HN-9 does nor express BP180 and BP230, although there is no gross deletion of the loci of the BP180 and BP230 genes, suggesting that a more subtle mechanism has silenced these genes. In conclusion, the failure to express certain hemidesmosomal proteins is a likely explanantion for th e functional and morphologic characteristics of UDC cells both in vivo and in vitro.