Breast Cancer

Breast cancer is the most frequent malignancy in women, contributing to 11.7% of all new cancer cases and 6.8% of all cancer-related deaths worldwide in 2020. Whilst medical interventions and diagnoses are a major focus of the breast cancer field, extensive research surrounding the inherent biology of breast cancer remains ongoing.

Research Areas
Literature (15)
Pathways (2)
Breast cancer is a heterogeneous disease that can be divided into several molecular subtypes defined by the expression of specific receptors namely: Luminal A/B, Basal-Like, Human Epidermal Growth Factor Receptor positive (HER2+) and Triple Negative Breast Cancer (TNBC) (see Table 1). HER2+ and TNBC are the least common subtypes but are associated with a poorer prognosis and higher mortality rate than the other subtypes. Initial diagnosis of breast cancer subtype is through histology and immunohistochemistry, which defines treatment strategies (Table 2).

Table 1. Breast cancer molecular subtypes.

Each subtype can be characterized by the expression of estrogen, progesterone and HER2 receptors. The expression of a particular receptor within a subtype is indicated by '+', absence of a particular receptor is indicated with '-'.

  Receptors
Subtype Estrogen Progesterone HER2
Luminal A + + -
Luminal B + + +
HER2+ - - +
TBNC - - -

The genomics of breast cancers have been thoroughly dissected revealing the heterogeneity in driver mutations. Studies have identified further subtypes within HER2+ and TNBC tumors, allowing stratification of these tumors and more refined treatment options. Inhibition of distinct pathways can be used in research to mimic treatment and show how tumor sub-populations adapt and respond. For example, Lapatinib (Cat. No. 6811), a HER-2 inhibitor, and Avagacestat (Cat. No. 6363), a γ-secretase inhibitor, have been used to explore the dynamics of HER2 heterogenous tumor populations and the resulting tumor response and adaptation. Another strategy uses targeted protein degradation to knockdown specific proteins in cells. For example, the PROTAC® Degrader SJF 1528 (Cat. No. 7262) degrades HER2 and EGFR and can be used to understand cancer pathways and responses to the degradation of these proteins.

Table 2. Histological breast cancer subtypes

Histological subtype Ductal Lobular

Preinvasive (25%)

Cells are limited to the basement membrane

Ductal carcinoma in situ

Likely to spread through ducts and cause distortion of structure

Tends to be unilateral

Small proportion progress to invasive

Lobular carcinoma in situ

No distortion of duct structure

Genetic E-cadherin loss

Can be bilateral

Invasive (75%)

Cells extend beyond the basement membrane

Invasive ductal carcinoma

Usually progression from ductal carcinoma

Fibrous, palpable mass

Lymph and blood metastasis

Invasive lobular carcinoma

Metastasis to GI, ovaries, uterus

Less fibrosis or palpable mass

Usually ER+

RNA in-situ hybridization (ISH) approaches are increasingly being applied to improve subtype characterization and to direct therapeutic selection. RNAscope™ is an example of this technique, allowing for biomarker identification, tumor subtyping and expression analysis, in addition to many other research applications. For example, RNA probes for EGFR and ERBB2 could be used to understand the transcriptional changes and responses within a cancer cell to treatment with Lapatinib. Combining these RNA-based assays with compound screens can also be a way to identify new genes, drugs of interest, or novel drug effects.

Despite the enormous heterogeneity, there are some genetic changes that are characteristic amongst several breast cancers and between different subtypes. Some of the most frequently mutated genes include oncogenic/hyper activation of PIK3CA, MAP2K4 and KMT2C, and loss of tumor suppressors such as TP53 and PTEN. BRCA1/2 mutations and their role in the increased familial risk of breast cancer is well established; mutations in BRCA1/2 and other DNA damage response (DDR) genes are frequently observed at later stages of breast cancer tumorigenesis. As a result of this, BRCA-deficient cells are reliant on other DNA repair pathways that can create therapeutic vulnerabilities, for example the RAD52 inhibitor 6-Hydroxy-DL-DOPA (Cat. No. 5740) inhibits proliferation in BRCA-deficient cells.

The ability of cancer cells to adapt and evolve is a key to therapeutic resistance and relapse. For example, inhibition of poly(ADP-ribose) polymerase (PARP) by Veliparib (Cat. No. 7026) is effective in treating tumors but resistance can develop. Using cell culture or breast tumor organoids, an understanding of the mechanisms of resistance to Veliparib and the adaptive use of other pathways could be gained. Drug combinations and synthetic lethality can also be studied in this way. For example Trastuzumab and Iressa (Cat. No. 3000) are known synergistic drug combinations, effectively inhibiting breast cancer cells across several subtypes.

PROTAC® is a registered trademark of Arvinas Operations, Inc., and is used under license.

New and Top Products for Breast Cancer Research

Click product name to view details and order

Target Top Products New Products
ALK A-83-01, SB 216763 TL 13-12, TL-13-112
mTOR Torin 1, Torin 2  
AURKB ZM 447439, TC-A 2317  
CTNNB1 XAV 939 (available sythesized to cGMP guidelines), iCRT 14 xSTAx-VHLL
BRAF SB 590885 CG 858
MET PHA 665752  
HSP90 VER 155008  
MDM2 SP 141, Nutlin 3a  
SRC A 419259 ND1-YL2
Wnt PKF 115584 (Calphostin C), FH 535  
MYC KJ Pyr 9  
CDK4/6 BSJ-03-204, Ribociclib BSJ-04-132
RAR BMS 753  
PIK3CB LY 294002 hydrochloride, Wortmannin  
MEK1 SL 327  
FOXM1 RCM 1  
BRD4 (+)-JQ1, MZ 1  
STAT3 Stattic, NSC 74859 HJC 0416
ESR1 ICI 182,780, G-1  
FOXA1 (+)-JQ1  
PARP1   SK 575

Literature for Breast Cancer

Tocris offers the following scientific literature for Breast Cancer to showcase our products. We invite you to request* or download your copy today!

*Please note that Tocris will only send literature to established scientific business / institute addresses.


Cancer Research Product Guide

Cancer Research Product Guide

A collection of over 750 products for cancer research, the guide includes research tools for the study of:

  • Cancer Metabolism
  • Epigenetics in Cancer
  • Receptor Signaling
  • Cell Cycle and DNA Damage Repair
  • Angiogenesis
  • Invasion and Metastasis
Cell Cycle and DNA Damage Research Product Guide

Cell Cycle and DNA Damage Research Product Guide

This product guide provides a review of the cell cycle and DNA damage research area and lists over 170 products, including research tools for:

  • Cell Cycle and Mitosis
  • DNA Damage Repair
  • Targeted Protein Degradation
  • Ubiquitin Proteasome Pathway
  • Chemotherapy Targets
Stem Cell Research Product Guide

Stem Cell Research Product Guide

This product guide provides a background to the use of small molecules in stem cell research and lists over 200 products for use in:

  • Self-renewal and Maintenance
  • Differentiation
  • Reprogramming
  • Organoid Generation
  • GMP and Ancillary Material Grade Products
Targeted Protein Degradation Research Product Guide

Targeted Protein Degradation Research Product Guide

This brochure highlights the tools and services available from Bio-Techne to support Targeted Protein Degradation research, including:

  • Active Degraders
  • TAG Degradation Platform
  • Degrader Building Blocks
  • Custom Degrader Services
  • Ubiquitin-Proteasome System Proteins and Assays
  • Assays for Protein Degradation
Autophagy Scientific Review

Autophagy Scientific Review

Written by Patricia Boya and Patrice Codogno, this review summarizes the molecular mechanisms, physiology and pathology of autophagy. The role of autophagy in cell death and its links to disease are also discussed. Compounds available from Tocris are listed.

Epigenetics Scientific Review

Epigenetics Scientific Review

Written by Susanne Müller-Knapp and Peter J. Brown, this review gives an overview of the development of chemical probes for epigenetic targets, as well as the impact of these tool compounds being made available to the scientific community. In addition, their biological effects are also discussed. Epigenetic compounds available from Tocris are listed.

Stem Cells Scientific Review

Stem Cells Scientific Review

Written by Kirsty E. Clarke, Victoria B. Christie, Andy Whiting and Stefan A. Przyborski, this review provides an overview of the use of small molecules in the control of stem cell growth and differentiation. Key signaling pathways are highlighted, and the regulation of ES cell self-renewal and somatic cell reprogramming is discussed. Compounds available from Tocris are listed.

Epigenetics Research Bulletin

Epigenetics Research Bulletin

Produced by Tocris and updated in 2014, the epigenetics research bulletin gives an introduction into mechanisms of epigenetic regulation, and highlights key Tocris products for epigenetics targets including:

  • Bromodomains
  • DNA Methyltransferases
  • Histone Deacetylases
  • Histone Demethylases
  • Histone Methyltransferases
Angiogenesis in Cancer Poster

Angiogenesis in Cancer Poster

Adapted from the 2015 Cancer Product Guide, Edition 3, this poster summarizes the pathogenesis of angiogenesis in cancer, as well as some of the main angiogenesis therapeutic targets.

Autophagy Poster

Autophagy Poster

Autophagy is a cellular process used by cells for degradation and recycling. Written by Patricia Boya and Patrice Codogno, this poster summarizes the molecular machinery, physiology and pathology of autophagy. Compounds available from Tocris are listed.

Cancer Metabolism Poster

Cancer Metabolism Poster

Adapted from the 2015 Cancer Product Guide, Edition 3, this poster summarizes the main targets for cancer metabolism researchers. Genetic changes and epigenetic modifications in cancer cells alter the regulation of cellular metabolic pathways. These distinct metabolic circuits could provide viable cancer therapeutic targets.

Cell Cycle & DNA Damage Repair Poster

Cell Cycle & DNA Damage Repair Poster

In normal cells, each stage of the cell cycle is tightly regulated, however in cancer cells many genes and proteins that are involved in the regulation of the cell cycle are mutated or over expressed. Adapted from the 2015 Cancer Product Guide, Edition 3, this poster summarizes the stages of the cell cycle and DNA repair. It also highlights strategies for enhancing replicative stress in cancer cells to force mitotic catastrophe and cell death.

Epigenetics in Cancer Poster

Epigenetics in Cancer Poster

Adapted from the 2015 Cancer Product Guide Edition 3, this poster summarizes the main epigenetic targets in cancer. The dysregulation of epigenetic modifications has been shown to result in oncogenesis and cancer progression. Unlike genetic mutations, epigenetic alterations are considered to be reversible and thus make promising therapeutic targets.

Stem Cell Workflow Poster

Stem Cell Workflow Poster

Stem cells have potential as a source of cells and tissues for research and treatment of disease. This poster summarizes some key protocols demonstrating the use of small molecules across the stem cell workflow, from reprogramming, through self-renewal, storage and differentiation to verification. Advantages of using small molecules are also highlighted.

Stem Cells Poster

Stem Cells Poster

Written by Rebecca Quelch and Stefan Przyborski from Durham University (UK), this poster describes the isolation of pluripotent stem cells, their maintenance in culture, differentiation, and the generation and potential uses of organoids.

Pathways for Breast Cancer

Apoptosis Signaling Pathway

Apoptosis Signaling Pathway

Apoptosis is a physiological process for cell death that is critical during aging and development. It may also be referred to as cell 'suicide'. Apoptosis can be triggered by events both inside and outside of the cell.
Estrogen Signaling Pathway

Estrogen Signaling Pathway

Estrogen is a steroid hormone that is responsible for the regulation of growth, differentiation and function of the reproductive system. Estrogen signaling is often dysregulated in breast cancer and osteoporosis.