Visualising the dynamics of live pancreatic microtumours self-organised through cell-in-cell invasion

Yukiko Miyatake,Yusuke Ohta,Maho Amano,Shunji Ikeshita,Kaori Kuribayashi-Shigetomi,Akira Kakugo,Kazuhisa Sueoka,Agus Subagyo,Masanori Kasahara,Takaharu Okajima,Toshiyuki Takahashi

doi:10.1038/s41598-018-32122-w

Yukiko Miyatake, Yusuke Ohta + Show 9 more

Open Access

https://doi.org/10.1038/s41598-018-32122-w

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Journal: Scientific Reports	Publication Date: Sep 19, 2018
Citations: 7	License type: open-access

Affiliation: Hokkaido University, Hokkaido hospital

Abstract

Pancreatic ductal adenocarcinoma (PDAC) reportedly progresses very rapidly through the initial carcinogenesis stages including DNA damage and disordered cell death. However, such oncogenic mechanisms are largely studied through observational diagnostic methods, partly because of a lack of live in vitro tumour imaging techniques. Here we demonstrate a simple live-tumour in vitro imaging technique using micro-patterned plates (micro/nanoplates) that allows dynamic visualisation of PDAC microtumours. When PDAC cells were cultured on a micro/nanoplate overnight, the cells self-organised into non-spheroidal microtumours that were anchored to the micro/nanoplate through cell-in-cell invasion. This self-organisation was only efficiently induced in small-diameter rough microislands. Using a time-lapse imaging system, we found that PDAC microtumours actively stretched to catch dead cell debris via filo/lamellipoedia and suction, suggesting that they have a sophisticated survival strategy (analogous to that of starving animals), which implies a context for the development of possible therapies for PDACs. The simple tumour imaging system visualises a potential of PDAC cells, in which the aggressive tumour dynamics reminds us of the need to review traditional PDAC pathogenesis.

Highlights

Despite accumulating evidence on the pathological features exhibited by cancer cells in various carcinomas, recent in vitro cancer cell studies have focused on the behavior of single cells in isolation
When PCI-55 cells were grafted intraperitoneally into SCID mice, similar peri-membranous expression of α-tubulin was observed in PCI-55 microtumours that colonized in the peritoneum in vivo (Fig. 4m). These results suggest that MTs composed of α-tubulin are involved in the formation of anchorage-dependent Pancreatic ductal adenocarcinoma (PDAC) microtumours
We found that anchorage-dependent PDAC microtumours on the micro/nanoplate integrally formed huge lamellipoedia (Fig. 6a), and the morphological polarity covered by membranous α-tubulin expression was very close to that of single cells (Fig. 6b)

Summary

Introduction

Despite accumulating evidence on the pathological features exhibited by cancer cells in various carcinomas, recent in vitro cancer cell studies have focused on the behavior of single cells in isolation. In current cancer research, directly linking in vitro cell-based studies with in vivo tissue-based pathological studies could result in a huge gap in our understanding. A recent study using genetically engineered mouse models of PDAC development reported that carcinoma cells could metastasise without activating EMT programs[19,20]. The micro/nanoplate enables visualisation of live tumour dynamics; the microtumours endocytose debris-derived surface nucleosides directly into vacuoles and accumulate dead cell-derived phosphatidylserine (PS) on their surfaces (resulting in PS externalisation, a cause of cancer immune evasion). The tumour dynamics visualised by our simple technology urge us to review the well-known pathogenesis of this intractable cancer and will contribute to the development of innovative new anticancer drugs

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