Cancer Stem Cells: Why Do Tumours Recur?

The main goal of modern medical science in the field of oncology is to increase survival in patients with malignancies. These diseases often recur after the initial successful treatment, a phenomenon largely due to the presence of the so-called “cancer stem cells” in the tumour. Due to their specific properties, these cells are more resistant to anticancer therapy than most other tumour cells.

In October 2019 the Research Institute at Medical University “Prof. Dr. Paraskev Stoyanov” – Varna (RIMU) started working on the TranStem project in the field of Translational Stem Cell Biology, funded by the European Commission, with EUR 2.5 million over a period of 5 years. TranStem project sets ambitious goals for science in Bulgaria and Europe, namely to promote state-of-the-art fundamental and applied stem cell research and its clinical application. To achieve these objectives, a strong research group has been created in this area, focused on research, development and innovation activities in stem cell research and therapies and regenerative medicines. The project attracted Dr. Manlio Vinciguerra, a leading international expert on cancer stem cells, as a European Research Area (ERA) Chair.

Who is Dr. Manlio Vinciguerra?

Dr. Vinciguerra has extensive professional experience, rich biography with a world-class scientific publication and leadership track record that enable him to lead the TranStem research team members at MU – Varna.

Manlio Vinciguerra was born in 1976 in Catania, Italy. He obtained a degree in Biomolecular Sciences from the University of Catania, Italy, in 1999. He received his Ph.D. in Internal Medicine (2004) and research training at the University of Geneva Medical School, Switzerland, and at the European Molecular Biology Laboratory (EMBL), in Italy and in Germany (2005-2011).

In 2008 he won the prestigious fellowship awarded by the European Molecular Biology Laboratory (EMBL), headquartered in Heidelberg, Germany.

In 2012 Dr. Manlio Vinciguerra obtained his first independent position and became Senior Lecturer at the Division of Medicine, University College London, UK. He created a small research group, which investigated the progression of liver diseases, from fat accumulation to cancer.

In 2016 he won a grant from the European Regional Development Fund (ERFD) to work on age-associated liver diseases and find out the role of cancer stem cells in the development of these diseases. During his research experience across Europe, Dr. Vinciguerra teamed up with a lot of great scientists, and together they were able to publish more than 175 papers.

He is a member of Who’s Who in Gerontology, Cancer Epigenetics Society (CES), Via Academy – Top Italian Scientists, International Cell Senescence Association (ICSA), European Association for the Study of Diabetes (EASD), European Association for the Study of the Liver (EASL), American Society of Cell Biology (ASCB).

Dr. Vinciguera, what are cancer stem cells?

Cancer stem cells are cancer cells that are not differentiated and are able to generate all type of cells present in a tumour. The can be considered as the malignant version of the normal stem cells present in healthy tissues.

Why do tumours relapse?

Current therapies to fight cancer, such as radiotherapy and chemotherapy, are ineffective against cancer stem cells, which are very resistant. An accredited hypothesis is that after radio- and chemo- therapies successfully kill cancer cells and the tumour mass shrinks, the surviving cancer stem cells can start to proliferate, differentiate and give rise to a recurrent new tumour.

Are there options to control cancer stem cells to prevent cancer recurrence?

Currently, there are no approved or effective options to kill cancer stem cells, in a way that they will not cause tumour recurrences.

Has specific therapy been developed targeted at suppressing cancer stem cells?

Again, unfortunately specific therapies do not exist, also because the localization and the number of cancer stem cells within tumours, are not entirely understood. Experimental therapies developed in many laboratories in the world include the use of nanoparticles targeting specific proteins on the surface of cancer stem cells, and the use of drugs targeting autophagy. Autophagy is a process by which cells „self-eat“ or recycle their inner components. Cancer stem cells survive by using autophagy, and the use of autophagy inhibitors can potentially kill them.

What is the role of prevention for successful cancer therapy? 

The European Commission presented this year the Europe’s Beating Cancer Plan. Prevention is fundamental; by reducing risky behaviours, mainly smoking and alcohol consumption, and promoting a healthy lifestyle, 40% of cancers can be prevented. In this respect, obesity is linked with a higher risk of getting 13 types of cancer. Unfortunately, 60% of cancers cannot be prevented; in these cases, early screening, access to good quality health care and support to patients and their caregivers are the main objectives of the European health plan.

The TranStem project provides an opportunity for research and innovation in the field of Translational Stem Cell Biology. How does the team of specialists of the Medical University of Varna work in this area?

Our team of specialists of the TranStem project, within the Medical University of Varna, are studying focus on specific human stem cell applications for diagnostic and therapeutic purposes. These applications include hematopoietic stem cells, mesenchymal stem cells, neural (brain) stem cells, cancer stem cells, induced pluripotent stem cells and corneal/limbal stem cells, developed within the research groups of our four principal investigators. Our innovative approaches include epigenetic drug targeting – in particular to kill cancer stem cells present in solid tumours, systems biology, 3D bioprinting and artificial intelligence.