Sangjucta Barkataki; Lisanne Wenting; Kenneth L. van Golen, PhD;

Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA

Helen F. Graham Cancer Center & Research Institute, Newark, DE 19713, USA

Abstract Cell lines in the study

Background

IBC and melanoma.

Role of TGFβ in the etiology of melanoma cutaneous metastasis

(Rufli 1995; Mauviel 2013).

TGFβ signalling switches breast cancer cells from cohesive to

single cell motility – EriK Sahai (2009)

Steven van Laere (2014) – circulating TGFb in patients. Very

low TGFb in IBC patients, TGFβ signal very poor in tumors.

Van Golen’s lab – TGFβ response, size of emboli and cluster

type to single cell invasion.

Skin metastasis in IBC and melanoma (Fidler 1990; Darvishian

2011; Garbe 2004).

Dr. van Golen – melanoma cells also forms emboli.

In melanoma -when TGFβ is increased in the stroma due to

radiation, there is single cell invasion (Rufli 1995; Mauviel 2013).

Breast cancer – most prevalent, 60% of cutaneous metastases

cases (Rosen2003).

Skin metastases representation of systemic spread of the

disease.

IBC cutaneous metastasis - chest wall recurrences.

Inflammatory Breast Cancer (IBC) is the deadliest form of epithelial

breast cancer, accounting for ~10% of breast cancer deaths in the

United States. A hallmark of IBC is the formation intralymphatic

emboli that are known to be chemotherapy and radiation resistant

and contribute to rapid metastasis. This form of breast cancer

progresses very quickly, expressing aggressive behavior. IBC and

melanoma share a number of similarities in disease presentation

and progression. Both spread via dermal lymphatics, form

intralymphatic emboli and have a propensity to form cutaneous

metastases. Melanoma can also present as “inflammatory

melanoma”, which resembles IBC phenotypically. Thus, new leads

for studying cutaneous metastasis can be gathered from the

melanoma literature. Studies demonstrate a role for transforming

growth factor beta (TGFβ) in the etiology of melanoma cutaneous

metastasis. TGFβ promotes tumor cell invasion and its expression

can be induced in the stroma by radiation treatment. Recently, our

lab has demonstrated low expression of TGFβ in IBC patients,

which we believe promotes cohesive invasion of IBC cells.

Stimulation of IBC cells with 2ng/ml of TGFβ causes altered tumor

cell behavior such as stimulating single cell invasion. The invasion

of KPL4, SUM149 and MDA-MB231 cell lines were significantly

higher in TGFβ stimulated cells compared to non-stimulated cells.

As in melanoma cells we hypothesize that radiation enhanced

local TGFβ production in the stroma. We radiated normal human

epidermal fibroblasts cells with 0gy, 0.5gy, 1.0gy, 2.5gy and 5.0gy

intensity and observed that the invasion was significantly higher in

1.0gy, 2.5gy and 5.0gy. Results shows presence of TGFβR2 in IBC

cells as well as TGFβ2 expressions by irradiated fibroblasts. Our

prediction is that the increase in the invasion of IBC cells is

because of TGFβ, which alters the cohesive nature of IBC cells,

and enhance single cell invasion. Moreover, radiation increases

TGFβ levels in the stroma, which is responsible for rapid

metastasis of IBC cells to the skin.

The influence of radiation induced TGFβ on the development of inflammatory breast cancer’s (IBC) cutaneous metastases

Preliminary data

Results: Fractionated dose

Results: Radiation therapy results in

IBC invasion

Results: TGFβ inhibitors SB431542

and LY2109761

Results: Gene expression in

fibroblasts and IBC cells

SUM149

AcknowledgementWe are sincerely grateful to Inflammatory Breast

Cancer Network Foundation for the funding for the

project.

Thank you DBCC for the recognition and the travel

award.

This study is dedicated to the memory of Kathleen

Strosser, who was an inspiration and enormous

supporter of our work

Conclusions

Results: Immunofluorescence and

Flow Cytometer