Common Effects on Cancer Cells Exerted by a Random Positioning Machine and a 2D Clinostat.

Benjamin Svejgaard,Jayashree Sahana,Ruth Hemmersbach,Xiao Ma,Johann Bauer,Markus Wehland,Jirka Grosse,Jens Hauslage,Ganna Aleshcheva,Thomas Juhl Corydon,Elisabeth Warnke,Sascha Kopp,Tawhidul Islam,Manfred Infanger,Daniela Grimm,Yoshiaki Taniyama

doi:10.1371/journal.pone.0135157

Abstract

In this study we focused on gravity-sensitive proteins of two human thyroid cancer cell lines (ML-1; RO82-W-1), which were exposed to a 2D clinostat (CLINO), a random positioning machine (RPM) and to normal 1g-conditions. After a three (3d)- or seven-day-culture (7d) on the two devices, we found both cell types growing three-dimensionally within multicellular spheroids (MCS) and also cells remaining adherent (AD) to the culture flask, while 1g-control cultures only formed adherent monolayers, unless the bottom of the culture dish was covered by agarose. In this case, the cytokines IL-6 and IL-8 facilitated the formation of MCS in both cell lines using the liquid-overlay technique at 1g. ML-1 cells grown on the RPM or the CLINO released amounts of IL-6 and MCP-1 into the supernatant, which were significantly elevated as compared to 1g-controls. Release of IL-4, IL-7, IL-8, IL-17, eotaxin-1 and VEGF increased time-dependently, but was not significantly influenced by the gravity conditions. After 3d on the RPM or the CLINO, an accumulation of F-actin around the cellular membrane was detectable in AD cells of both cell lines. IL-6 and IL-8 stimulation of ML-1 cells for 3d and 7d influenced the protein contents of ß1-integrin, talin-1, Ki-67, and beta-actin dose-dependently in adherent cells. The ß1-integrin content was significantly decreased in AD and MCS samples compared with 1g, while talin-1 was higher expressed in MCS than AD populations. The proliferation marker Ki-67 was elevated in AD samples compared with 1g and MCS samples. The ß-actin content of R082-W-1 cells remained unchanged. ML-1 cells exhibited no change in ß-actin in RPM cultures, but a reduction in CLINO samples. Thus, we concluded that simulated microgravity influences the release of cytokines in follicular thyroid cancer cells, and the production of ß1-integrin and talin-1 and predicts an identical effect under real microgravity conditions.

Highlights

Prolonged spaceflights often cause deleterious health problems in humans
The cells of the follicular thyroid cancer cell lines ML-1 and RO82-W-1 were cultivated for 3d and 7d on the random positioning machine (RPM), on the 2D CLINO, and under normal static laboratory 1g-conditions
Up to the seventh day, the pH remained in the normal range, irrespective of whether the cells were cultured on the RPM, under 1g or on the CLINO

Summary

Introduction

Prolonged spaceflights often cause deleterious health problems in humans. A number of spaceflight effects have been extensively studied in the past and reviewed [1,2,3,4]. Some effects may be explained by well-known physiology; e.g. the lack of gravitational stress on the leg musculature results in a rapid loss of bone and muscle, and the lack of the gravitational vector causes problems related to balance and eye movements [1]. It had been shown that annulling of gravity influences the molecular mechanisms of the cells directly [3]. Multicellular aggregates were detected, which resembled the organs from which their cells had been derived [14]

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Conclusion