“The experience of visiting another lab broadened my vision of how research is conducted” – Hugo Poplimont’s Travel Fellowship

Hugo posing next to the SP8 confocal microscope.

With COVID-19 putting a stop to travel throughout 2020 and 2021, we’re beginning to have have our first Travel Fellows return post-coronavirus. The EACR in collaboration with Worldwide Cancer Research provides Travel Fellowships of up to €3,000 to enable early-career cancer researchers to gain new skills through a short-term visit to a lab or research group in another country.

We ask our Travel Fellows to send us a report of their experiences at their home institutions. You can read about Hugo’s time in Barcelona in his report below:

You can read about other Travel Fellowship awardees and their experiences here.

Name: Hugo Poplimont
Job title: Postdoctoral researcher
Home institute: St Anna Children’s Cancer Research Institute, Vienna, Austria
Host institute: Centre for Genomic Regulation, Barcelona, Spain
Dates of visit: 14/04/2022 – 30/04/2022
Research: I study cancer metastasis, which is responsible for 90% of cancer death. Metastasis is the spread of cancer cells to a different body part from where it started. While navigating the body, cancer cells end up being squeezed, notably in small blood capillaries. Interestingly, when squeezed, cancer cells can become more motile, and this could lead them to invade new organs more efficiently. During my visit to Verena Ruprecht’s lab, I used a device to squeeze cancer cells to understand how squeezing can make cells more motile, to eventually try to impair this process to inhibit the spread of metastasis.

Why did you decide to apply for an EACR Travel Fellowship?

I applied to this travel fellowship to support my visit to Verena Ruprecht’s laboratory in Barcelona in which I learned how to confine cancer cells in vitro. The undergoing project is strongly focusing on cancer metastasis which is a topic of interest for the EACR and the funding allowed me to cover the travel and accommodation costs in Barcelona for two weeks.

Why did you choose the host lab?

The Verena Ruprecht’s lab published a landmark paper on the impact of cell confinement on migration (Science, 2020). They notably showed that upon confinement myosin II is recruited to the cortex of the cells which switch cells from an idle to a migratory phenotype. This paper is one of the pieces of literature that laid the foundation of our scientific hypothesis for this project, it is therefore only natural that we approached Verena Ruprecht to start a collaboration with her lab. Interested in the project, she assigned Fabio Pezzano, a PhD student in her lab, to start performing preliminary confinement experiments with cells we sent to her lab. After seeing the promising results, obtained by Fabio, we decided to further strengthen the collaboration to perform more complex experiments and learn how to use the confinement devices ourselves by organizing this visit to her laboratory.

Can you summarise the research you did or what you learned on your visit?

Hugo working on the SP8 confocal microscope.

During my visit to the CRG, I studied how mechanosensation is involved in metastasis in Osteosarcoma cancer cells. We hypothesised that upon confinement, cancer cells become more invasive and that this invasiveness is associated with cPLA2 activation. To verify this, I squeezed cells (that I engineered and sent to the lab prior my arrival) using two different confinement methods (magnetic or vacuum pump confinement). High-resolution time-lapse images were acquired before during and after confinement by confocal microscopy. First, I confined different Osteosarcoma cell lines to study their behaviour (quantifying blebbing and increased motility upon confinement).

Then I used Osteosarcoma cell lines expressing fluorescent probes allowing me to follow cell activation (GCaMP8s) and to study pathways that could potentially be activated upon confinement and important for metastasis (cPLA2 KO and cPLA2 fluorescent reporter).

Our results showed that Osteosarcoma cells get activated (increase of intracellular calcium concentration) and in some cases show cPLA2 activity upon confinement. Preliminary analysis also shows that cPLA2 expression correlates with increased cell motility and blebbing which correlates with the increased invasive behaviour we observed with these cells when transplanted in zebrafish.

Describe a ‘typical day’ on your visit

I would work exclusively with Fabio Pezzano who is a PhD student who extensively contributed to the landmark Science paper published by the lab in 2020 on cell confinement. A typical day will start with the extensive cleaning of the compression device we would use for the day (cleaning with Ethanol, MilliQ water, plasma cleaning, priming with PLL PEG…), after this we would prepare the cells in the tissue culture room and then go down to the basement of the building to perform confocal imaging and set up time-lapses during which we would prepare the second batch of cells and equipment.

The view from the institute

Lunch break would take place on the institute terrace with the view on the beach. A typical day would also include meetings or the manufacturing of the coverslips with PDMS pillars of 3µm height designed specifically for the need of my project. I was fully involved in the laboratory routine and participated to lab meetings and seminar taking place at the institute and had the occasion to present my research.

What were you able to do that you could not have achieved in your home lab?

I was able to learn how to use devices specifically designed to confine cells in vitro. I also brought some devices (two magnetic confinement devices and a coverslips with PDMS pillars) to our laboratory back in Vienna in order to further continue this project. Discussing my project in depth and testing different confinement heights and devices I was able to tailor the experiment to the specific needs of my project and test it directly on the cell I sent which would have been impossible without the help of cell confinement experts and a broad range of confinement devices available at the CRG.

Hugo visiting the Cathedral of the Sagrada Familia.

Did you take part in any interesting local or cultural activities?

During the weekends, I visited the cultural landmarks the city of Barcelona has to offer such as the cathedral of the Sagrada Familia, the Park Guell and various houses designed by Gaudi. I also enjoyed the market of la boqueria and tried various local food such as the Catalan sausage “Botifarra”.

What was a personal highlight of your trip?

The personal highlight of my trip was a long-awaited experiment using a new cell line I engineered that expresses a fluorescent reporter for probing intracellular calcium concentration: GCAMP8s. When the intracellular calcium concentration increases, the fluorescence intensity of the probe increases too. It was amazing to see the fluorescence of the cell, live under the SP8 confocal microscope, quickly increasing while we were slowly confining the cells to a very precise height of 3µm. Not only this confirmed our hypothesis that Osteosarcoma cells are activated upon confinement but the images acquired were beautiful (one of the picture I sent with me posing next to the confocal microscope shows images of these cells expressing GCAMP8s on the microscope’s screen).

Was the host institution very different from your own?

The CRG in Barcelona is quite different from my institution in Vienna. It is located in an amazing building (PRBB) shared between a hospital, the university of Pompeu Fabra and also between other research institutes such as the EMBL and the Institute of Biologia Evolutiva. I particularly liked the wealth of equipment available with a broad range of microscopes including a spinning disc, a Leica SP8 and SP5, various Zeiss fluorescent microscopes. I also particularly enjoyed the design of the building and the amazing view on Barcelona and on the sea it offered. It was also a good occasion to get feedbacks from scientist working with a strong focus on fundamental cell biology (cell migration, morphodynamic plasticity, cellular mechanosensing…).

Did you have a personal mentor or anyone who particularly helped you?

From left to right: Hugo, his mentor (Fabio Pezzano), and the head of the group (Verena Ruprecht) on the terrace of the CRG institute.

My personal mentor was Fabio Pezzano and he was completely dedicated to teaching me cell confinement during my visit. Fabio is an Italian PhD student in the Ruprecht’s lab. He just submitted his thesis manuscript recently and is an expert in cell confinement. He is notably one of the main contributors of the research paper that laid the foundation for our hypothesis.

He was very patient and enthusiastic and is an amazing person to work with. He made sure I would make the most of my time in the lab by booking all microscopes in advance, having all the cells thawed before my arrival and preparing all the devices and protocols I needed; he planned everything perfectly. Every experiment I performed was performed with him. He not only taught me the science and technique behind cell confinement but help me navigate the city and taught me some words of Spanish, Catalan and Italian.

How has the trip inspired you in your research?

This trip was the occasion to see a different research environment and culture in a country I never worked before. It was also a very good occasion to have in depth discussions about the project I am undertaking with a different point of view coming from cell/developmental biologist outside my institute and to design technically challenging experiments that required the knowledge and expertise of the people in Verena’s Ruprecht lab. Fabio, my mentor is an inspiring person, passionate by science, well organised and an amazing teacher setting an example on how people should teach scientific techniques.

Have you brought back any specific knowledge that has benefited your home lab?

Techniques to confine cells in vitro are very new and experimental and it was essential for me to be at the CRG to learn how to confine cells and to understand how the devices work and what are the caveat and the different problems I can encounter with such technique. I not only brought back specific knowledge and technique concerning cell confinement in vitro, but I also brought back two cell confinement devices along with custom made geometrical confinement coverslips made by Fabio Pezzano and specifically designed for our needs after various test experiments and discussions that took place during my visit. Talking to the different experts at the CRG in Barcelona was also essential to further understand and get some inside tips and unpublished details about how different cells behave when confined.

Does your lab plan to do any future collaboration with the host lab?

Our laboratory is actively collaborating with Verena Ruprecht’s lab and we are notably applying to a FWF stand alone grant with a project in which she will assist us if successful. The data gathered during this trip is broadening our understanding of cancer cell migration during metastasis and will certainly be included in a future publication.

How has this visit been beneficial to your research and your career?

This visit was a proper practical introduction to the world of cell confinement and mechanosensation, it was also the opportunity to interact with new researchers and extend my network. This trip was highly beneficial for my research project as I acquired new knowledge and practical skills that I would not have been able to acquire otherwise. Additionally, I gathered data that is strongly reinforcing the hypothesis in my project, bringing me one step forward towards the understanding of metastatic mechanisms. Not only the skills and knowledge obtain will help me during my career but also the experience of visiting another lab and institute and experiencing another type of management broaden my vision of how research is conducted and will surely be beneficial for my career.

Want to find out more?

If you are interested in applying for the Travel Fellowship scheme, please click the EACR Travel Fellowships logo for more information.