Published in:
Open Access
01-10-2019 | Thyroid Cancer | Original paper
Interplay between thyroid cancer cells and macrophages: effects on IL-32 mediated cell death and thyroid cancer cell migration
Authors:
Yvette J. E. Sloot, Katrin Rabold, Thomas Ulas, Dennis M. De Graaf, Bas Heinhuis, Kristian Händler, Joachim L. Schultze, Mihai G. Netea, Johannes W. A. Smit, Leo A. B. Joosten, Romana T. Netea-Maier
Published in:
Cellular Oncology
|
Issue 5/2019
Login to get access
Abstract
Purpose
Interleukin 32 (IL-32) is a pro-inflammatory cytokine of which different isoforms have been identified. Recently, IL-32 has been shown to act as a potent inducer of cell migration in several types of cancer. Although previous research showed that IL-32 is expressed in differentiated thyroid cancer (TC) cells, the role of IL-32 in TC cell migration has not been investigated. Furthermore, tumour-associated macrophages (TAMs) may play a facilitating role in cancer cell migration. The aim of this study was to explore whether the interaction between TC cells and TAMs results in increased expression of IL-32 in TC cells and to investigate whether this affects TC cell migration.
Methods
TPC-1 cells were co-culture with TC-induced or naive macrophages. Next, transcriptome analysis on TPC-1 cells was performed and supernatants were used for stimulation of TPC-1 cells. IL-32β and IL-32γ were exogenously overexpressed in TPC-1 cells using transient transfection, after which an in vitro gap closure assay was performed to assess cell migration, and the expression of migratory factors was assessed using RT-qPCR.
Results
We found that TC-induced macrophages induced IL-32 expression in TC cells and that TAM-derived TNFα was the main inducer of IL-32β expression in TC cells. Overexpression of IL-32β and IL-32γ did not affect TC cell migration, but increased cell death. Finally, we found that IL-32β overexpression led to increased mRNA expression of the pro-survival cytokine IL-8, while the expression of other migratory factors was not affected.
Conclusions
From our data, we conclude that TAM-derived TNFα induces IL-32β in TC cells. Although IL-32β does not affect TC cell migration, alternative splicing of IL-32 towards the IL-32β isoform may be beneficial for TC cell survival through induction of the pro-survival cytokine IL-8.