We have further demonstrated that alternatively spliced PR mRNA is present in MDA-MB-231 cells and in reportedly PR-negative breast tumour tissue which could encode the truncated PR proteins detected by the C-terminal antibody.
RNA expression analyses of several human cell lines with different tissue origin and paired human tumor/normal tissues, as well as of several PR+ and PR- breast tumors revealed that PIBF mRNA was overexpressed in highly proliferating cells independent of the presence of PR.
The 26 successfully retrieved archival NF1 breast tumours were more often associated with unfavourable prognostic factors, such as oestrogen and progesterone receptor negativity and HER2 amplification.
In rat mammary tumour models, treatment with the PR antagonist completely suppressed the growth of established tumours and prevented the development of breast tumours.
The aim of this study was to measure osteonectin mRNA and protein expression in breast tumour biopsies and compare these with oestrogen (ER) and progesterone receptor (PR) levels in the same tumours.
The present study has shown for the first time that phosphorylation of ER-alpha Ser167, but not Ser118, and expression of PRA and PRB, as well as ER-alpha and PR in primary breast tumors are predictive of response to endocrine therapy, whereas expression of ER-beta1 and ER-betacx/beta2 did not affect response to the therapy.
By utilizing a big dataset (TCGA) with sufficient statistical power, we found that high expression of miRNA-18a, miRNA-205, and miRNA-744 in the breast tumor samples were all associated with better overall survival in ER/PR-positive, lymph node-negative disease supporting their role as a tumor suppressor in breast cancer.
Herein, we evaluated the anti-tumor activity of a commercially available PR modulator, ulipristal acetate (UPA), and a new selective and passive PR antagonist "APR19" in a novel preclinical approach based on patient-derived breast tumor (HBCx-34) xenografted in nude mice.
Of the 141 breast tumors, 45 samples (32%) had high HRD scores and were associated with high histological grade (P = 0.001), negative progesterone receptor (P = 0.018), high Ki67 index (P = 0.032), and BRCA1 promoter methylation (P = 3.6e-07).
P1 was hypermethylated in metastatic lymph nodes compared with matched primary breast tumours whereas P2 hypermethylation was associated with loss of either oestrogen receptor or progesterone receptor.
Our results show that kin17 expression was markedly increased in clinical breast tumors and was associated with tumor grade, Ki-67 expression, p53 mutation status and progesterone receptor expression, which were assessed in a clinicopathologic characteristics review.
An absolute and relative increase in ER-beta mRNA levels in ER negative and PR negative breast tumors, which rarely respond to endocrine therapy, suggests the possible involvement of up-regulation of ER-beta mRNA in the development of estrogen-independent tumors.
An interesting association was found between ER/PR (Oestrogen/Progesterone receptor) and HER2/Neu (Human epidermal growth factor receptor-2) positivity with HPV occurrence in breast tumours.
In order to determine whether changes in D6-PR variant expression could occur during tumorigenesis, its expression was investigated by reverse transcription and polymerase chain reaction in ten normal reduction mammoplasty samples, nine breast tumours with high PR levels (> 100 fmol mg(-1) protein) and eight breast tumours with low PR levels (< 15 fmol mg(-1) protein), as determined by ligand binding assay.
However, when combined with MSI/LOH in AR, ERβ and CYP19 genes, we were able to detect significant associations with the GSTP1 wild-type genotype in PR (progesterone receptor) negative breast cancers or the CYP17 wild-type genotype in ER (estrogen receptor) and PR-negative breast tumors.
Collectively, these findings support the role of PR-B in breast epithelial cell integrity and reinforce the importance in targeting PR-B as a potential strategy to restrict breast tumor cell invasion and metastasis.
Discordances between the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), expression between primary breast tumors and their subsequent brain metastases (BM) were investigated in breast cancer patients.