A key hurdle in treating breast cancers is intratumoural heterogeneity, or the presence of multiple different cell populations within the same tumour that have distinct characteristics such as gene expression, metabolism and ability to divide, spread and grow.

These cells can also respond with varying levels of sensitivity to standard therapies, and ultimately, are a contributing factor to therapeutic resistance.

A team of researchers led by Dartmouth's and Dartmouth-Hitchcock's Norris Cotton Cancer Center have a new understanding of how tumour heterogeneity arises and how it can be curtailed to render tumours less metastatic and more sensitive to therapy.

The team identified that the mammary basal cell lineage contributes to breast cancer heterogeneity, fuelling the outgrowth of multiple aggressive tumour subpopulations.

"Through the activation of a signalling pathway driven by protein kinase A (PKA), we are able to limit the self-renewal potential of basal cells, which impedes the outgrowth of metastatic, therapy-resistant tumour cell subpopulations," says Principal Investigator and cancer biologist Diwakar Pattabiraman, PhD, who is also the corresponding author of the study.

The team's findings, "Limiting Self-Renewal of the Basal Compartment by PKA Activation Induces Differentiation and Alters the Evolution of Mammary tumours," are newly published in Developmental Cell.

Pattabiraman notes that developing an understanding of how to tackle this heterogeneity is crucial for successful therapeutic intervention.

"While there are no approaches to targeting PKA currently, there could be some therapeutic utility in pursuing the inhibition of its substrates such as Sox4. We plan to study the PKA-Sox4 connection in further detail, specifically to explore the possibility of targeting the transcriptional ability of Sox4."

Source: Dartmouth-Hitchcock Medical Center