Dataset Information

Heterogeneity of luminal breast cancer characterised by immunohistochemical expression of basal markers.

ABSTRACT:

Background

Luminal A breast cancer defined as hormone receptor positive and human epidermal growth factor receptor 2 (HER2) negative is known to be heterogeneous. Previous study showed that luminal A tumours with the expression of basal markers ((cytokeratin (CK) 5 or CK5/6) or epidermal growth factor receptor (EGFR)) were associated with poorer prognosis compared with those that stained negative for basal markers. Prompted by this study, we assessed whether tumour characteristics and risk factors differed by basal marker status within luminal A tumours.

Methods

We pooled 5040 luminal A cases defined by immunohistochemistry (4490 basal-negative ((CK5 (or CK5/6))- and EGFR-) and 550 basal-positive ((CK5 (or CK5/6+)) or EGFR+)) from eight studies participating in the Breast Cancer Association Consortium. Case-case comparison was performed using unconditional logistic regression.

Results

Tumour characteristics and risk factors did not vary significantly by the expression of basal markers, although results suggested that basal-positive luminal tumours tended to be smaller and node negative, and were more common in women with a positive family history and lower body mass index.

Conclusions

Most established breast cancer risk factors were similar in basal-positive and basal-negative luminal A tumours. The non-significant but suggestive differences in tumour features and family history warrant further investigations.

SUBMITTER: Sung H

PROVIDER: S-EPMC4742579 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature

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Publications

Heterogeneity of luminal breast cancer characterised by immunohistochemical expression of basal markers.

Sung Hyuna H Garcia-Closas Montserrat M Chang-Claude Jenny J Blows Fiona M FM Ali H Raza HR Figueroa Jonine J Nevanlinna Heli H Fagerholm Rainer R Heikkilä Päivi P Blomqvist Carl C Giles Graham G GG Milne Roger L RL Southey Melissa C MC McLean Catriona C Mannermaa Arto A Kosma Veli-Matti VM Kataja Vesa V Sironen Reijo R Couch Fergus J FJ Olson Janet E JE Hallberg Emily E Olswold Curtis C Cox Angela A Cross Simon S SS Kraft Peter P Tamimi Rulla M RM Eliassen A Heather AH Schmidt Marjanka K MK Bolla Manjeet K MK Wang Qin Q Easton Douglas D Howat William J WJ Coulson Penny P Pharoah Paul D P PD Sherman Mark E ME Yang Xiaohong R XR

British journal of cancer 20151217 3

<h4>Background</h4>Luminal A breast cancer defined as hormone receptor positive and human epidermal growth factor receptor 2 (HER2) negative is known to be heterogeneous. Previous study showed that luminal A tumours with the expression of basal markers ((cytokeratin (CK) 5 or CK5/6) or epidermal growth factor receptor (EGFR)) were associated with poorer prognosis compared with those that stained negative for basal markers. Prompted by this study, we assessed whether tumour characteristics and ri ...[more]

PMID: 26679376

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Project description:BACKGROUND:The majority of estrogen receptor-positive (ER?+) breast cancers respond to endocrine therapies. However, resistance to endocrine therapies is common in 30% of cases, which may be due to altered ER? signaling and/or enhanced plasticity of cancer cells leading to breast cancer subtype conversion. The mechanisms leading to enhanced plasticity of ER?-positive cancer cells are unknown. METHODS:We used short hairpin (sh)RNA and/or the CRISPR/Cas9 system to knockdown the expression of the dependence receptor UNC5A in ER?+ MCF7 and T-47D cell lines. RNA-seq, quantitative reverse transcription polymerase chain reaction, chromatin immunoprecipitation, and Western blotting were used to measure the effect of UNC5A knockdown on basal and estradiol (E2)-regulated gene expression. Mammosphere assay, flow cytometry, and immunofluorescence were used to determine the role of UNC5A in restricting plasticity. Xenograft models were used to measure the effect of UNC5A knockdown on tumor growth and metastasis. Tissue microarray and immunohistochemistry were utilized to determine the prognostic value of UNC5A in breast cancer. Log-rank test, one-way, and two-way analysis of variance (ANOVA) were used for statistical analyses. RESULTS:Knockdown of the E2-inducible UNC5A resulted in altered basal gene expression affecting plasma membrane integrity and ER? signaling, as evident from ligand-independent activity of ER?, altered turnover of phosphorylated ER?, unique E2-dependent expression of genes effecting histone demethylase activity, enhanced upregulation of E2-inducible genes such as BCL2, and E2-independent tumorigenesis accompanied by multiorgan metastases. UNC5A depletion led to the appearance of a luminal/basal hybrid phenotype supported by elevated expression of basal/stem cell-enriched ?Np63, CD44, CD49f, epidermal growth factor receptor (EGFR), and the lymphatic vessel permeability factor NTN4, but lower expression of luminal/alveolar differentiation-associated ELF5 while maintaining functional ER?. In addition, UNC5A-depleted cells acquired bipotent luminal progenitor characteristics based on KRT14+/KRT19+ and CD49f+/EpCAM+ phenotype. Consistent with in vitro results, UNC5A expression negatively correlated with EGFR expression in breast tumors, and lower expression of UNC5A, particularly in ER?+/PR+/HER2- tumors, was associated with poor outcome. CONCLUSION:These studies reveal an unexpected role of the axon guidance receptor UNC5A in fine-tuning ER? and EGFR signaling and the luminal progenitor status of hormone-sensitive breast cancers. Furthermore, UNC5A knockdown cells provide an ideal model system to investigate metastasis of ER?+ breast cancers.

Dataset Information

Heterogeneity of luminal breast cancer characterised by immunohistochemical expression of basal markers.

Background

Methods

Results

Conclusions

Publications

Heterogeneity of luminal breast cancer characterised by immunohistochemical expression of basal markers.

Similar Datasets

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