Key event in breast cancer development(reportedly) described

[Lani]

ABSTRACT: The changes of estrogen receptor-? variants expression in breast carcinogenesis: Decrease of estrogen receptor-?2 expression is the key event in breast cancer development [Journal of Surgical Oncology]


Backgound and Objectives: Although more than five variant forms of estrogen receptor-? (ER?) have been identified, their role has not been identified. This study was carried out to investigate the changes of ER? variants in breast cancer development.

Methods: Using reverse transcription polymerase chain reaction (RT-PCR) and triple primer PCR (TP-PCR), the expression levels of ER? variants mRNA were measured in 66 paired normal and cancer tissues. The relative expression level of ER? variants were compared between normal and cancer tissues, and also compared according to various clinicopathological parameters.

Results: Among ER? variants, ER?2 and ER?5 consist of the major proportion of ER? expression both in normal and cancer tissues. The ER? and ER?2 expression levels decreased significantly in the cancers compared with corresponding normal tissues, particularly in ER?-expressing cancers. However, ER?5 expression level increased significantly in the cancers, especially in those of postmenopausal patients. The relative increase of ER?5 expression in cancer tissues was associated with favorable differentiation.

Conclusions: Decrease of ER?2 is thought to be the key reason for the decrease in ER? expression in cancer tissues, and it is particularly associated with the development of ER?-expressing breast cancer.