Oliver Florey

Research Summary

Research in our lab is focused on the related topics of autophagy (self eating), macroendocytosis (digestion of extracellular material) and entosis (a recently discovered form of cell cannibalism). These are 3 distinct but inter-related forms of cellular ‘eating’, which play an important role in normal biology and become deregulated during ageing or disease (eg cancer).

Our work exploits a combination of molecular and cellular biology, state-of-the-art microscopy (long-term timelapse imaging, spinning disk confocal and electron microscopy) and proteomics (mass spectrometry).

Existing projects aim to define the molecular mechanisms which underlie cellular eating, with a particular focus on the emerging pathway of non-canonical autophagy. We are also investigating the intriguing relationship between entosis and cancer.

Latest Publications

Macropinocytosis and autophagy crosstalk in nutrient scavenging.
Florey O, Overholtzer M

Adaptive strategies used by cells to scavenge and recycle essential nutrients are important for survival in nutrient-depleted environments such as cancer tissues. Autophagy and macropinocytosis are two major mechanisms that promote nutrient recycling and scavenging, which share considerable, yet poorly understood, cross-regulation. Here we review recent findings that connect these starvation response mechanisms and discuss the implications of their crosstalk. This article is part of the Theo Murphy meeting issue 'Macropinocytosis'.

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Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 374, 1471-2970, 2019

PMID: 30967004

Entosis Controls a Developmental Cell Clearance in C. elegans.
Lee Y, Hamann JC, Pellegrino M, Durgan J, Domart MC, Collinson LM, Haynes CM, Florey O, Overholtzer M

Metazoan cell death mechanisms are diverse and include numerous non-apoptotic programs. One program called entosis involves the invasion of live cells into their neighbors and is known to occur in cancers. Here, we identify a developmental function for entosis: to clear the male-specific linker cell in C. elegans. The linker cell leads migration to shape the gonad and is removed to facilitate fusion of the gonad to the cloaca. We find that the linker cell is cleared in a manner involving cell-cell adhesions and cell-autonomous control of uptake through linker cell actin. Linker cell entosis generates a lobe structure that is deposited at the site of gonad-to-cloaca fusion and is removed during mating. Inhibition of lobe scission inhibits linker cell death, demonstrating that the linker cell invades its host while alive. Our findings demonstrate a developmental function for entosis: to eliminate a migrating cell and facilitate gonad-to-cloaca fusion, which is required for fertility.

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Cell reports, 26, 2211-1247, 2019

PMID: 30893595

Imaging Noncanonical Autophagy and LC3-Associated Phagocytosis in Cultured Cells.
Jacquin E, Fletcher K, Florey O

Monitoring of ATG8 proteins by western blotting and immunofluorescence microscopy are the most common methods to monitor the autophagy pathway. However, it has recently been shown that ATG8 proteins can be lipidated to non-autophagosome, single-membrane compartments through a noncanonical autophagy pathway. This is commonly found to occur during macro-endocytic processes such as phagocytosis, where it has been termed LC3-associated phagocytosis, and upon lysosomotropic drug treatment. Therefore, care is required when interpreting data based on ATG8 in order to conclude whether a signal relates to the canonical or noncanonical pathway. Here we provide methods to monitor noncanonical autophagy through fluorescence microscopy.

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Methods in molecular biology (Clifton, N.J.), 1880, 1940-6029, 2019

PMID: 30610705

entosis and the formation of a cell-in-cell structure by MCF10A cells
A) Sequence of images showing entosis and the formation of a cell-in-cell structure by MCF10A cells in suspension. Cell 1 is engulfed by Cell 2.

B) H&E staining from a human breast carcinoma, arrows point to cell-in-cell structures (taken from Biomax.us).

C) Immunofluorescent staining of b-catenin in a cell-in-cell structure from a human breast tumor.

D) Immunofluorescent staining of E-cadherin in a cell-in-cell structure from MCF10A cells.