hAG-2, the human homologue of the Xenopus laevis cement gland gene XAG-2, is coexpressed with estrogen receptor in breast cancer cell lines.

hAG-2, the human homologue of the Xenopus laevis cement gland gene Xenopus Anterior Gradient-2 (XAG-2), has been found to be coexpressed with estrogen receptor (ER) in breast cancer cell lines by using suppression subtractive hybridization. Sequence analysis of clones obtained from a human breast adenocarcinoma MCF7 cDNA library suggests that at least three mRNA transcripts, differing in their 3'-untranslated regions, are transcribed from the hAG-2 gene. Northern blot analyses identified two principal hAG-2 signals in all ER-positive breast carcinoma cell lines that were absent in cell lines not expressing, or minimally expressing, ER. Coexpression of hAG-2 with ER suggests that hAG-2 may be involved in the tumor biology specific to the well-differentiated phenotype of hormonally-responsive breast cancers.