Furthermore, some pivotal fusion genes like ESR1-C6orf97 with COBRA1-C9orf167 and VAPB-IKZF3 with ACACA-STAC2 were found in Luminal A and Luminal B breast cancer, respectively.
We documented that AGTR1 overexpression occurred in the luminal A and B subtypes of breast cancer, was mutually exclusive of HER2 expression, and correlated with aggressive features that include increased lymph node metastasis, reduced responsiveness to neoadjuvant therapy, and reduced overall survival.
Finally, we examined the association between expression of AhR and BRCA-1 promoter CpG methylation in human triple-negative (TNBC), luminal-A (LUM-A), LUM-B, and epidermal growth factor receptor-2 (HER-2)-positive breast tumor samples.
Then we detected that the PKIB and pAkt respectively of immunohistochemical expression and cellular localization of four subtypes in patients which were luminal A, luminal B, HER2+/ER-type and triple negative breast cancer type.
High ALDH18A1 and high GLS protein expression was observed in the oestrogen receptor (ER)+/human epidermal growth factor receptor (HER2)- high proliferation class (Luminal B) compared with ER+/HER2- low proliferation class (Luminal A) (P=0.030 and P=0.022 respectively), however this was not observed with mRNA.
The percentages of ALDH1 positive expression in each tissue subtype were as follows: Luminal A, 20%; luminal B, 24%; human epidermal growth factor 2 (HER2), 35%; triple-negative, 21%.
We performed MethyLight analysis of the methylation status of 15 promoter CpG island loci involved in breast cancer progression (APC, DLEC1, GRIN2B, GSTP1, HOXA1, HOXA10, IGF2, MT1G, RARB, RASSF1A, RUNX3, SCGB3A1, SFRP1, SFRP4, and TMEFF2) and determined cancer stem cell phenotype by CD44/CD24 and ALDH1 immunohistochemistry in 36 luminal A, 33 luminal B, 30 luminal-HER2, 40 HER2 enriched, and 40 basal-like subtypes of breast cancer.
This finding is further supported by the positive association between the expression of MUC1 and p50 in Luminal A and Luminal B subtypes through analyzing breast cancer databases.
This finding is further supported by the positive association between the expression of MUC1 and p50 in Luminal A and Luminal B subtypes through analyzing breast cancer databases.
Not all PR low luminal A cases had poorer outcome compared to the PR high luminal A cases; poor prognosis was only limited to those with also low Bcl2 (log-rank = 23.568, P < 0.001 compared to PR high Bcl2 high cases).
Investigation of antiapoptotic Bcl-2 family members in clinical breast cancer datasets revealed greater expression and more frequent gene amplification of <i>MCL1</i> as compared with <i>BCL2</i> or <i>BCL2L1</i> (Bcl-xL) across three major molecular breast cancer subtypes, Luminal (A and B), HER2-enriched, and Basal-like.
β2M expression was positively correlated with p-CREB, p-SGK1, and Bcl-2 expression and had no correlation with HIF-1α, VEGF, and p-ERK1/2, whereas p-SGK1 exhibited a significantly positive correlation with Bcl-2 expression in cancer tissues of patients with luminal A breast cancer, which coincide with the results obtained from the same molecular types of breast cancer cells except CREB signaling.
The expression of the Bcl-2 gene differed by subtype, with the luminal A and luminal B subtypes more likely to overexpress the Bcl-2 gene (89.1% luminal A, 80.0% luminal B vs 47.6% basal-cell-like and 40.0% HER-2/neu, P < .000).
The findings of less aggressive luminal A and B subtypes in older patients, and the positive correlation with ER, PR and Bcl-2 expression reveal the potential efficacy of Bcl-2 as a marker of hormone responsiveness in these patients.
This comparison showed that immunohistochemical bio-profiles select those cases not associated with high risk-of-recurrence of disease (luminal-A/B and luminal A/B Bcl2) and those that are instead at high risk and therefore worthy of chemotherapy (luminal-B ki67 and luminal-B Bcl2/Ki67), strongly suggesting to only submit PGR-positive/Bcl2-Ki67 altered cases to Oncotype Dx, thus reducing the number of cases to be tested.
Finally, we examined the association between expression of AhR and BRCA-1 promoter CpG methylation in human triple-negative (TNBC), luminal-A (LUM-A), LUM-B, and epidermal growth factor receptor-2 (HER-2)-positive breast tumor samples.
Genomic DNA from 131 formalin-fixed paraffin-embedded (FFPE) tumors (luminal A and B, HER2+ and triple negative BC) with known BRCA1 mutation status or unscreened for BRCA1 mutation were analysed by array Comparative Genomic Hybridization (array CGH).
Especially, besides RFS, reduced BTG2 also indicated worse overall survival and distant metastasis free survival in breast cancer patients who were classified as luminal A.
High CAIX mRNA expression was significantly associated with poor survival in patients with basal-like, luminal B and triple-negative breast cancer, but not luminal A and HER+ subtypes.
Finally we reclassified early tumours in the surrogate molecular subtype according to the 2013 St. Gallen Conference criteria and found that 13/40 cases (33%) classified as luminal A were G3 with the PPH3 mitotic score and could benefit from chemotherapy.