The interactions between GPR30 and the major biomarkers in infiltrating ductal carcinoma of the breast in an Asian population.
OBJECTIVE
G-protein-coupled receptor 30 (GPR30) has been reported to be a novel estrogen receptor alpha (ERalpha) in vitro. Therefore, the interactions among GPR30, ERalpha, progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER-2/neu), and their prognostic utilities in the infiltrating ductal carcinoma (IDC) of the breast were evaluated.


METHODS
Messenger RNA (mRNA) levels of GPR30, ERalpha, PR and HER-2/neu in the tumor samples of 118 Taiwanese IDC patients and 27 non-tumor mammary tissues were measured via quantitative polymerase chain reaction analyses. The correlations of GPR30 mRNA levels with clinical parameters, i.e. tumor/non-tumor, ERalpha, PR, HER-2/neu, age, lymph node metastasis, lymph-vascular invasion, grade, stage and patient survival, were assessed by using appropriate statistical analyses.


RESULTS
GPR30 expression was observed to be lower in IDC (p < 0.001) than in non-tumor mammary tissues. Importantly, GPR30 mRNA level was positively correlated with that of ERalpha (p = 0.001) and PR (p = 0.001) but not correlated with that of HER-2/neu when they were analyzed as continuous variables. However, lower GPR30 was noticed in tumors with HER-2/neu protein overexpression. GPR30 expression was not correlated with age, lymph node metastasis, lymph-vascular invasion, grade and stage in IDC. GPR30 expression was not an independent prognostic factor for patient survival.


CONCLUSIONS
GPR30 expression is downregulated in IDC. GPR30 is preferentially co-expressed with ER and/or PR but is lowly expressed in HER-2/neu(+) tumors. The correlation of GPR30 expression with clinical parameters, including patient survival, was not evident in this cohort.
Kuo
Wen-Hung
WH
Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan.
Chang
Li-Yun
LY
Liu
Daisy Li-Yu
DL
Hwa
Hsiao-Lin
HL
Lin
Jen-Jen
JJ
Lee
Po-Huang
PH
Chen
Chiung-Nien
CN
Lien
Huang-Chun
HC
Yuan
Ray-Hwang
RH
Shun
Chia-Tung
CT
Chang
King-Jen
KJ
Hsieh
Fon-Jou
FJ
D044466:Asian People; D014408:Biomarkers, Tumor / Q000378:metabolism; D001940:Breast / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism* / Q000401:mortality; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism* / Q000401:mortality; D015536:Down-Regulation; D047628:Estrogen Receptor alpha / Q000378:metabolism; D005260:Female; D006801:Humans; D011379:Prognosis; D016016:Proportional Hazards Models; D012333:RNA, Messenger / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013624:Taiwan / Q000453:epidemiology
D014408:Biomarkers, Tumor; D047628:Estrogen Receptor alpha; D012333:RNA, Messenger; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D043562:Receptors, G-Protein-Coupled; D011980:Receptors, Progesterone; C109584:GPER1 protein, human; C508053:ERBB2 protein, human