Objective: To study if the gene SNC73 (IgHalpha1) is expressed in human epithelial cancer cell line and to interpret the recombination mechanism.
Methods: Human epithelial cancer cells of SW480 line were cultured. RT-PCR and Western blotting were used to examine the expression of SNC73, recombination activating gene 1 (RAG1), and RAG2. The RT-PCR products were confirmed by sequencing. Immunohistochemistry was used to detect the expression of IgHalpha1, Igkappa, and Iglambda in these epithelial cancer cells.
Results: The human epithelial cancer cell line (SW480) positively expressed SNC73, RAG1, and RAG2. IgHalpha1 and Igkappa was strongly expressed in SW480 cells, but Iglambda was undetectable. The sequence of the constant region of SNC73 in SW480 cells is identical to that of IgA1. Both sequencing and Western blotting showed that the RAG1 and RAG2 expressed in SW480 cells were identical to that expressed in pre-B lymphocytes.
Conclusion: Immunoglobulin alpha-1 gene is expressed in non-lymphoid cells, which may be a potential genetic marker for the development of colorectal cancer. Recombination signal sequence (RSS)-mediated recombination may take part in the rearrangement of immunoglobulin alpha-1 gene in human epithelial cancer cell line.