Mechanisms of three-dimensional growth of thyroid cells during long-term simulated microgravity.

Sascha Kopp,Elisabeth Warnke,Markus Wehland,Johann Bauer,Manfred Infanger,Daniela Grimm,Nils E Magnusson,Thomas Juhl Corydon,Ganna Aleshcheva,Ruth Hemmersbach

doi:10.1038/srep16691

Abstract

Three-dimensional multicellular spheroids (MCS) of human cells are important in cancer research. We investigated possible mechanisms of MCS formation of thyroid cells. Both, normal Nthy-ori 3–1 thyroid cells and the poorly differentiated follicular thyroid cancer cells FTC-133 formed MCS within 7 and 14 days of culturing on a Random Positioning Machine (RPM), while a part of the cells continued to grow adherently in each culture. The FTC-133 cancer cells formed larger and numerous MCS than the normal cells. In order to explain the different behaviour, we analyzed the gene expression of IL6, IL7, IL8, IL17, OPN, NGAL, VEGFA and enzymes associated cytoskeletal or membrane proteins (ACTB, TUBB, PFN1, CPNE1, TGM2, CD44, FLT1, FLK1, PKB, PKC, ERK1/2, Casp9, Col1A1) as well as the amount of secreted proteins (IL-6, IL-7, IL-8, IL-17, OPN, NGAL, VEGFA). Several of these components changed during RPM-exposure in each cell line. Striking differences between normal and malignant cells were observed in regards to the expression of genes of NGAL, VEGFA, OPN, IL6 and IL17 and to the secretion of VEGFA, IL-17, and IL-6. These results suggest several gravi-sensitive growth or angiogenesis factors being involved in 3D formation of thyroid cells cultured under simulated microgravity.

Highlights

Three-dimensional multicellular spheroids (MCS) of human cells are important in cancer research
We could show that both cell types form 3D aggregates on the Random Positioning Machine (RPM) after long-term exposure
This study suggests that growth and angiogenic factors determine differences in spheroid formation behaviour of the malignant and the healthy thyroid cells

Summary

Introduction

Three-dimensional multicellular spheroids (MCS) of human cells are important in cancer research. Many cell types in 3D multicellular culture models were found to assume a more or less normal cellular architecture and exhibited gene expression profiles that were reflective of an authentic differentiated phenotype found in the real tissue[3,8]. By means of this experimental approach, mechanisms and pathways can be studied that control cancer cell growth and function. The FTC-133 cell line was derived from a PDTC from a 42-year-old male patient[24] It comprises follicular thyroid cancer cells, which formed large 3D aggregates, when cultured under real microgravity (r-μ g) and simulated μ g10,18,25. A similar reaction of both cell types to the microgravity environment may be due to a general reaction of cells to low-gravity conditions

Objectives

Methods

Results

Discussion

Conclusion