Quantitative profiles of the mRNAs of ER-alpha and its novel variant ER-alpha36 in breast cancers and matched normal tissues.

Abstract

OBJECTIVE:

The novel estrogen receptor-alpha (ER-alpha) variant ER-alpha36 is reported to be functional in the estrogen signaling pathway and is related to tamoxifen resistance in breast cancer. However, ER-alpha36 tends to be a favorable factor for survival in patients without tamoxifen therapy. To investigate the mechanisms behind this paradox, we determined the differences between the transcriptional profiles of ER-alpha36 and full-length ER-alpha (ER-alpha66) in breast cancers and matched normal tissues.

METHODS:

We analyzed ER-alpha36 and ER-alpha66 messenger RNA (mRNA) levels in 74 pairs of breast cancers and matched normal tissues using a real-time quantitative polymerase chain reaction (PCR) assay, and correlated the results with their clinicopathological characteristics.

RESULTS:

Breast cancers expressed lower ER-alpha36 mRNA levels than matched normal tissues regardless of their ER-alpha66 expression status. Down-regulation of ER-alpha36 mRNA was correlated with local progression, lymph node metastasis, and advanced cancer stage. The level of ER-alpha66 mRNA was lower in ER-alpha negative breast cancers compared with matched normal tissues. No differences in ER-alpha66 mRNA levels were observed during cancer progression.

CONCLUSION:

Down-regulation of ER-alpha36 is associated with carcinogenesis and progression of breast cancer.

• Authors: Yi Zheng, Jing Zhang, Zhen-zhen Xu, Jian-ming Sheng, Xiao-chen Zhang, Hao-hao Wang, Xiao-dong Teng, Xiao-jiao Liu, Jiang Cao, Li-song Teng
• Journal: Journal of Zhejiang University. Science. B (J Zhejiang Univ Sci B) Vol. 11 Issue 2 Pg. 144-50 (Feb 2010) ISSN: 1862-1783 [Electronic] China
• PMID: 20104649 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA Primers
• Estrogen Receptor alpha
• RNA, Messenger
• RNA, Neoplasm

Topics

• Adult
• Aged
• Aged, 80 and over
• Base Sequence
• Breast Neoplasms (genetics, metabolism, pathology)
• DNA Primers (genetics)
• Down-Regulation
• Estrogen Receptor alpha (chemistry, genetics)
• Female
• Genetic Variation
• Humans
• Middle Aged
• Neoplasms, Hormone-Dependent (genetics, metabolism, pathology)
• Polymerase Chain Reaction
• RNA, Messenger (genetics, metabolism)
• RNA, Neoplasm (genetics, metabolism)