Uncovering the Downstream Effectors of FOXC2 in Basal Breast Cancer

Overview

Topic status: We're looking for students to study this topic.

Large scale molecular profiling studies have identified five main subtypes of human breast cancers that differ in their gene expression profiles and clinical outcomes. Of these subtypes, patients with tumours classified within the basal subtype generally have a worse prognosis. The aggressive behaviour of these tumours may be attributable to their similarity in gene expression with cells that have undergone an epithelial-tomesenchymal transition (EMT). In addition, these breast cancers have characteristics of tumour initiating breast cancer stem cells (BrCSCs). As a result, basal breast cancer cells lines contain increased numbers of CD44pos/CD24neg BrCSCs. Recently, the forkhead transcription factor, FOXC2, was shown to induce EMT in mammary epithelial cells leading to increased in vivo metastasis, with increased expression of FOXC2 correlating with aggressive basal tumours from human clinical breast cancer specimens. In collaboration with Dr Sendurai Mani (University of Texas), we have performed microarray gene expression studies on transformed breast epithelial cells constitutively overexpressing FOXC2 to identify possible FOXC2 target genes. This microarray data in combination with publicly available gene expression data from human breast tumour samples will be used to identify critical downstream targets of FOXC2 in basal breast cancer cell lines with the aim of developing novel targeted therapies for basal breast cancers expressing FOXC2.

Hypothesis: Inhibition of key downstream targets of FOXC2 will reverse the aggressive behaviour of FOXC2 expressing Basal breast cancer cell lines.

Aim 1: Identify possible downstream targets of FOXC2 by analyzing microarray gene expression data from cells overexpressing FOXC2 in comparison with expression data from basal cell lines

Aim 2: Validate direct targets of FOXC2 by in vitro analysis of FOXC2 binding to promoter regions of target genes using chromatin-immunoprecipitation (CHIP) and qRT-PCR

Aim 3: Confirm a functional role of identified target genes in FOXC2 expressing basal breast cancer cell lines using lentiviral mediated delivery of gene specific shRNAs

Methods and techniques that will be developed in the course of this project:

  • Bioinformatic analysis of microarray gene expression data
  • Cell culture & In vitro functional assays for invasion and cancer stem cell properties
  • Western blotting, qRT-PCR and CHIP
  • Lenti-viral mediated shRNA gene knockdown
  • FACS analysis of cancer stem cell populations
Study level
PhD, Honours
Supervisors
QUT External Dr Sendurai Mani
Organisational unit

Science and Engineering Faculty

Research area

Cell and Molecular Biosciences

Contact

Please contact the supervisor.