Winning Abstract of Breaking News ISCOMS 2016

Title: Transient Receptor Potential Channels and Inflammatory Breast Cancer A novel approach to understand

Author: Emma van der Harst

Field of research: Oncology

Inflammatory breast cancer (IBC) is known as a unique type of breast cancer affecting relatively young women.
It is characterized by extremely high metastatic potential, which begins with invasion of tumor emboli in the
lymphatic system. IBC specific treatment is desirable to improve the dismal outcome of this disease. Transient
Receptor Potential (TRP) channels are widely expressed non‐selective cation channels, which play an important
role in the calcium homeostasis of both excitable and non‐excitable cells. In cancer, TRP channels show an
altered expression and are involved in processes of tumor initiation and progression. However, TRP channels
have yet to be studied in IBC. Aim of study: to determine of TRP channel expression in IBC, and subsequently,
the involvement of these channels in tumor emboli formation, adhesion and invasion in a preclinical setting.

Material & methods
Expression of TRP channels was investigated using conventional Polymerase Chain Reactions (PCR). IBC cell
lines SUM 149 and KPL‐4, non‐IBC cell line MDA‐MB‐231 and non‐tumorigenic cell line MCF10A were used.
Thereafter, IBC tumor emboli were formed in the presents of selective and non‐selective TRP channel
inhibitors and activators. Lastly, invasion assays of treated and untreated tumor emboli were performed.

The PCR results revealed that TRP channels are widely expressed in IBC cell lines, with a unique pattern
compared to non‐IBC and non‐tumorigenic cell lines. Additionally, TRPV‐1 and multiple members of the TRPC
subfamily showed a difference in TRP channel expression between IBC cells grown in monolayer and IBC cells
grown in tumor emboli. While treatment with the selective TRPV‐1 agonist capsaicin showed a difference in
emboli size, treatment with non‐selective TRPC antagonist progesterone caused a significant difference in
emboli number, size, morphology, and invasive capabilities.

These preliminary studies suggest a role for TRP channels in the metastatic behaviour of IBC. In order to
examine the therapeutic potential of these channels, further research is needed to confirm these results and
determine the underlying molecular pathways.