Enhanced expression of the UROC28 gene in human breast cancer: Relationship to ERBB2 gene expression

Background: ERBB2, a highly important oncogene in invasive breast cancer, is not only a prognostic factor but also a predictive marker for response to therapeutic agents. Recently, An et al. (10) identified a novel gene, UROC28, that is also overexpressed in breast cancer. To examine possible interrelationships, we quantitated UROC28 and ERBB2 mRNA in breast cancers. Materials and Methods: The expression of UROC28 and ERBB2 mRNA in breast cancer tissues were determined using RT-PCR. The expression was also examined in T-47D breast cancer cells treated with estrogen. Results: UROC28 mRNA expression was greater in cancers than in noncancerous tissues (p<0.0001), as was ERBB2 mRNA. ERBB2 and UROC28 gene expression was dose-dependently down-regulated in T-47D breast cancer cells treated with estradiol. However UROC28 mRNA and ERBB2 mRNA expression did not correlate with one another. Conclusion: These results indicate that UROC28 may be a useful target molecule in breast cancer diagnosis and treatment, complementing ERBB2.