“Prevention is always the best way to fight cancer,” says toxicologist Antonio Guerrero

How did you come to join RECETOX? 

I always wanted to do my postgraduate studies abroad. At first, I planned to do my master’s in another country, like Germany, but then COVID-19 happened. It was almost impossible to leave Mexico because of restrictions, so I stayed and did my master’s there. But after that, I was completely convinced about doing my PhD abroad, so I looked it up and this offer from RECETOX came up. 

What was your field? 

My background is in environmental health sciences. It’s a mix of social sciences, human health, environmental health, and more. Some of my colleagues work on social topics, others with biodiversity and species conservation, and others with public health. I chose the human health path. After my bachelor’s, I started a master’s in biomedical sciences focused on human health. I’ve always liked toxicology—human toxicology specifically. During my bachelor’s, I worked with in vitro toxicology, which is what I do now. I worked with cells, animal models like rats and mice, and even frogs and snails. 

What was your master’s project? 

I worked with a pottery community. Pottery sometimes uses dyes contaminated with lead, so these people are constantly exposed. My project focused on lead exposure and health effects like immune responses. I loved it because it combined lab work with community interaction. I enjoyed talking to people and building trust. 

And then Canada? 

Yes, I got a scholarship for a six-month research stay at the University of Saskatchewan. It was my first time abroad—and my first flight ever! I worked on developmental toxicology, mostly in the lab, with piglets. They were tiny and screamed a lot! My job was castration—I needed the testes to generate a 3D cell model resembling the tissue (organoids). Then I exposed cells to chemicals and observed the effects such as genotoxicity. I loved that project and even considered doing my Ph.D. there, but the projects in the Toxicology Department were more focused on ecotoxicology, not human toxicology, so I looked elsewhere. 

How did you find your current position? 

Through EURAXESS. I applied to positions in Europe and Canada. Eventually, I chose this project because I liked the topic of carcinogenicity risk assessment and the financial opportunities. My current supervisor, Pavel Babica, interviewed me and accepted me. 

Your current project? 

We identify chemicals that can promote carcinogenesis. For carcinogens there are two categories: genotoxic carcinogens, which damage DNA, and non-genotoxic carcinogens, which act through other mechanisms like avoiding cell death, promoting inflammation, or disrupting cell signaling. My project focuses on cell communication—gap-junction intercellular communication. These are protein channels connecting cells, like straws, allowing molecules to pass. Healthy cells communicate to maintain homeostasis. If chemicals disrupt this, cells may overgrow and become cancerous. We test chemicals suspected to be non-genotoxic carcinogens by evaluating this communication. 

Why is this important? 

For prevention. Cancer is the second leading cause of death worldwide. If we can identify carcinogenic chemicals early, we can prevent them from reaching the market. Also, we use cell-based methods, reducing animal testing, which is expensive, time-consuming, and sometimes not relevant for humans. 

Do you see any differences in the approach to science in Mexico, Canada, and the Czech Republic? 

In Mexico, resources are limited. I used to count cells manually under a microscope. Here, machines do it automatically. In Canada, I ordered kits and got them in less than a month; in Mexico, it took six months. Canada and Czech Republic invest more in science, making research faster. 

Looking back to your childhood or teenage years, what brought you to science? 

In high school, I liked biology and chemistry, so I chose environmental sciences. I’m not great at math, but I enjoy statistics when applied to real problems. 

What do you enjoy the most? 

The feeling that I’m contributing to a better world. I’m not Superman, but leaving something valuable behind for future generations matters to me. 

What do you miss about your country, if anything? 

Yes, the food—but also the life I had there. Moving abroad changes you, but it’s a chance to grow and discover new things. 

Do you have any message for young or future scientists? 

Believe in yourself and aim high. In Mexico, we have great scientists, but we need to seek bigger opportunities globally to improve our science.