Neuroblastoma Research Dream Team 2017

It is fantastic to see so knowledgeable and enthusiastic young researchers in my research group. This year, the team is multinational with the Irish students mixing with Belgian and Malaysian. All together they are cracking the code of neuroblastoma microenvironment and tumour cells communication through understanding main differences between conventional cancer cell models and tumours.

The big research plan of the entire team consists of more smaller and focused projects to be completed within 10-12 weeks. All projects are unrestricted, they are driven by the intellectual curiosity of these students. This way is full of ups and downs, frustrations and encouragements when techniques do not work or reagents do not come in as expected. Some cancer concepts can also work differently in the given settings. Simple questions are bringing more challenges than expected.  But at the end of the road is the best reward – contribution to the conceptual advancement of neuroblastoma microenvironment.

 

 

The Neuroblastoma Research Dream Team 2017: Dr. John Nolan, NCRC funded researcher, RCSI, Joe O’Brien, TCD MSc student, Ciara Gallagher, DIT undergraduate student, Jessica Tate, RCSI Medical student, Larissa Deneweth, Erasmus student, Ghent, Ying Jie Tan, TCD MSc student.

Feeling good, excited and accomplished

This week can be rated for sure as feeling good, excited and accomplished. A UK based charity – Neuroblastoma UK has awarded a small grant to characterise a pre-clinical model of neuroblastoma which is a collaborative project between our lab and Tissue Engineering Research Group at RCSI. This project will study features of neuroblastoma cells growing on collagen-based scaffolds. The NBUK grant will contribute to one of the most expensive parts of the study – characterisation of cell secreting proteins using antibody-based profiling platforms.

Another research was accomplished yesterday –  John Nolan had his Voice Viva examination and successfully defended his PhD Thesis. This 3 year PhD project was funded by the National Children’s Research Centre. As his supervisor, I am delighted for him and wish him best of luck in his research career.

 

 

Cells having a handshake in 3D

Neuroblastoma cells growing on scaffolds.

Continue research into 3D neuroblastoma models, we imaged cells growing on collagen based scaffolds using confocal microscopy. This technique is very popular in cell biology providing depth in cell imaging.

Here you can see cells growing on scaffolds: white dots – cells, irregular fibers – collagen containing scaffold.

 

 

The results are fascinating! Cell nucleus is in blue (DAPI), cell actin is in red (phalloidin). You will be able also to see how two cells ‘having a handshake’. It is happening just in the middle.

May whatever we do at the lab today make a difference in another person’s life someday in the future.

Mei Rin Liew

I am a medical student at Penang Medical College under a twinning programme with the Royal College of Surgeons in Ireland. I studied my pre-clinical years at RCSI Dublin. In the summer of 2015, I had the opportunity to join the RCSI Research Summer School (RSS) Programme. I was mentored by Dr Olga Piskareva, from Cancer Genetics, Molecular and Cellular Therapeutics (MCT) Department, RCSI.  Being in this lab was simply one of the greatest experiences I have in my life; it was really rewarding.

My RSS project investigated the role of VDAC-1 protein on chemotherapy resistance in neuroblastoma. The only research focus of this lab is to find key players in neuroblastoma pathogenesis and to advance anti-cancer therapy.

Neuroblastoma cell line SK-N-AS. The cell line in my experiments.

I was entrusted with the task of splitting cells. I would plate them onto 96-well plates, add cisplatin drug and measure their viability afterwards. It may sound simple here, but the whole process required passion and hard-work.

Prior to this, I did not have any experience in the medical research field. During my first two weeks, everything seemed so tough; however, they became easier as the weeks flew by. My mentor, Olga, and the other staff and PhD students (Garret, John and Ross) were helpful and always guided me to explore my potentials. This programme taught me various new things which I would not have acquired on a normal day-to-day basis in school.

Introduction to Malaysian cuisine.

The people at Cancer Genetics were warm and wonderful. The hospitality, love and guidance cannot be quantified and words cannot express my immense gratitude towards them. It has been fascinating and I cherish every moment I spent there. We bonded over our weekly breakfast and tea sessions so well, and I am indeed grateful for being a part of this big family. It is my sincere wish that this positive spirit of togetherness will be preserved and will grow stronger in the future. This is something special, and I think ours is the best lab at RCSI!

Under this RSS, all the participants attended skills workshops and weekly Discovery Series lectures. We were also given a Biography of Cancer by Siddhartha Mukherjee to read; evidently a good read. Here are the links to the RCSI Research Summer School Student Testimonial Videos.

I returned to Penang Medical College to further my studies in my clinical years. I took part in the PMC Research Day 2016 in which I was awarded the First Prize in Oral Presentation. I would like to dedicate this success to Olga and everyone who has been with me throughout my time at Cancer Genetics. Without all the guidance, I would not have made it this far.

I strongly urge students to take part in the research opportunities, because you gain invaluable experiences that you do not get elsewhere. May whatever we do at the lab today make a difference in another person’s life someday in the future.

Mei Rin Liew

Towards 3D neuroblastoma cell models

It seems I have got a conference season. Three conferences within 2 months – no complains though. This time I went to the Matrix Biology Ireland Meeting in Galway. It was fantastic mix of topics and speakers ranging from new approaches in bone and heart repair to new matrixes in reconstruction of body tissues and diseases in the lab to minimise use of animals in pre-clinical studies.

My talk was focused on neuroblastoma microenvironment and cell-to-cell communication through exosomes. I wrote about it in October post. I talked about things that did work and did not as well as new directions. One of the new directions is reconstructing neuroblastoma by growing neuroblastoma cells on collagen based scaffolds in 3D. Collagen constitutes most of our tissues to keep it shape and strength. These scaffolds are sponge-like matrixes built from collagen and other components. Of course cells grow differently on these matrixes. They have a different shape and growing properties in 3D. Neuroblatoma cells look like water drops on the cotton wool-like collagen scaffolds. In contrast, when they grow on plastic in 2D, they are flat. Studies show that cells in 3D respond to cytotoxic stress in a similar pattern as if being within a body (details in recent reviews 1-4).  It would be a great breakthrough once these models are optimised for neuroblstoma research  field. It will help to test all new and known drugs in the environment close to clinical settings. It could be a step forward to personilised therapies for children with neuroblastoma by isolating cancer cells, growing them in 3D and testing how they respond to all therapies available. It will facilitate more efficient design of treatment for relapsed or poorly responding tumours, sparing patients unnecessary rounds of chemotherapy and ultimately increasing survival.

 

Neuroblatoma cells look like water drops on the cotton wool like collagen scaffolds. In contrast, when they grow on plastic in 2D, they are flat. Arrows point towards cells.
This is microscopic images of neuroblatoma cells growing on the collagen scaffolds and plastic. Arrows point towards cells.

 

I’ve always felt that a selection of abstracts for an oral presentation is biased. The overall background and views of conference organisers would affect works selected for an oral presentation.  The same abstract was not selected for an oral presentation by one committee, but was supported by the other.  Never give up!

Readings:

  1. Schweiger PJ, Jensen KB.Modeling human disease using organotypic cultures. Curr Opin Cell Biol. 2016 43:22-29.
  2. Salamanna F, Contartese D, Maglio M, Fini M. A systematic review on in vitro 3D bone metastases models: A new horizon to recapitulate the native clinical scenario? Oncotarget. 2016 7(28):44803-44820.
  3. Picollet-D’hahan N, Dolega ME, Liguori L, Marquette C, Le Gac S, Gidrol X, Martin DK. A 3D Toolbox to Enhance Physiological Relevance of Human Tissue Models. Trends Biotechnol. 2016 34(9):757-69.
  4. Nyga A, Neves J, Stamati K, Loizidou M, Emberton M, Cheema U. The next level of 3D tumour models: immunocompetence. Drug Discov Today. 2016 21(9):1421-8.

How we work with cancer cell lines?

How we work with cancer cell lines?

The very first human cancer cell line was developed from a patient with an aggressive cervical cancer in 1951. This cell line was called HeLa after the patient name – Henrietta Lacks. This is the most popular and robust cancer cell line in biomedical research. Since then, other cancer cell lines were developed including neuroblastoma.

The first successful neuroblastoma ‘cell lines’ were cell populations from tumours that were adapted to grow for a short period in the lab environment in 1947. These tumour cell populations were used as a tool for diagnosis. This success inspired other researchers to develop long-term or immortal neuroblastoma cell lines. To date different neuroblastoma cell lines exist.

Cancer cell lines are sensitive and delicate in handling. They can only grow in the safe environment. Researchers have to protect them against bacteria, low temperatures, and too acidic/alkaline conditions. We protect cancer cells from bacteria contamination by handling them in cabinets where all plastic and media are sterile.

Handling neuroblastoma cells in the cell culture cabinet.
Handling neuroblastoma cells in the cell culture cabinet.

Cancer cells like to grow in conditions similar to conditions in human body. They like temperature of 36.6 – 37C. To achieve it special ‘green cell houses’ – CO2 incubators are built, which maintain the constant temperature, humidity and CO2 concentration.

We place cells in plastic dishes or containers called flasks and keep flasks in the ‘green cell houses’.
We place cells in plastic dishes or containers called flasks and keep flasks in the ‘green cell houses’.

The cell growth and well being are checked regularly using microscopes. Healthy cells are to have similar shape, even distribution and grow attached to the plastic surface. Most microscopes have a camera attached to the top and linked to a computer. It helps to take picture of growing cells and record changes in cell behaviour.

Microscopic examination of drug resistant neuroblastoma cells KellyCis83. Cells look healthy and can be kept for another 2-3 days to form a more dense population.
Microscopic examination of drug resistant neuroblastoma cells KellyCis83. Cells look healthy and can be kept for another 2-3 days to form a more dense population.

 

Recommended reading

  1. Skloot, R. The Immortal Life of Henrietta Lacks 2011
  2. Thiele CJ. Neuroblastoma Cell Lines. Human Cell. 1998. 1-35 p.
  3. Murray M, Stout A. Distinctive Characteristics of the Sympathicoblastoma Cultivated in Vitro: A Method for Prompt Diagnosis. Am J Pathol. 1947;23(3):429–41.

 

Drug resistant neuroblastoma cells

Children with neuroblastoma undergo several cycles of intensive chemotherapy to stop disease progression with the final aim to eliminate the tumour. Chemotherapy includes carboplatin or cisplatin in various combinations with drugs such as cyclophosphamide, ifosfamide, doxorubicin, etoposide, topotecan and vincristine (1). Nevertheless, in average 1 in 5 children with stage 4 disease do not respond to therapy. Up to 50% of children that do respond experience disease recurrence with tumour resistant to multiple drugs and more aggressive behaviour that all too frequently results in death.

The development of drug resistance is the major obstacle in treatment of neuroblastoma. To tackle this problem, researchers need to study different models of disease using cell lines, 3D tumour cell models, mice models and have access to clinical samples.

The first stage in testing drugs is to understand their killing ability of cancer cells. At this stage, researchers test drugs using cell lines. Cell lines are derived from tumours which were surgically removed from children with neuroblastoma. Researchers usually take a small piece of tumour straight after surgery and bring it into the laboratory.  Here, they place this piece into special solution that has enzymes to separate cells from each other. Then the suspension of all kind of tumour cells is placed into plastic dishes or flasks in a highly nutrient media to let cells grow. Cells that can adapt to these conditions start to grow, divide and produce a new generation of cancer cells. Researchers look after their growth, inspect their shape and behaviour; and test them on the presence of tumour markers. Once identity of these cells is confirmed they become a cell line and obtain a name. These cells keep majority of characteristics of the parental tumour and represent very useful tools in cancer research.

In our lab we use such cell lines to study neuroblastoma resistance to drugs. To understand changes in neuroblastoma biology during the development of drug resistance, we created drug resistant neuroblastoma cell lines (2). We treated three neuroblastoma cell lines CHP212, SK-N-AS and Kelly with cisplatin – a common drug in anticancer therapy. SK-N-AS and Kelly cells are sensitive to this drug, while CHP212 cells responded to this drug at much higher levels that the other two. Cells were grown in media containing cisplatin for several weeks. During this period most of the cells responded to cisplatin and died. Then we let cell survivors to recover in media without drug. This cycle was repeated several times until we got a population of cell survivors that can stand doses of cisplatin that can kill 50% of parental cells.  It took us more than 6 months to generate cisplatin resistant neuroblastoma cell lines CHP212Cis100, SK-N-ASCis24 and KellyCis83.

At the next step, we studied differences between these cell lines. We first compared their behaviour and cell shapes. Two resistant cell lines KellyCis83 and CHP212Cis100 started to grow faster, but SK-N-ASCis24 – slower than their parental cell lines. Interestingly, these cells also became more resistant to other drugs such as doxorubicin, etoposide, temozolomide, irinotecan and carmustin. These results are very important as they demonstrate that one drug can activate the cell defense systems that allow to escape toxicity of other drugs. These cell lines can be used to test new drugs and find those that can overcome developed resistance.

Cisplatin resistant cells also changed their appearance. Most dramatic changes occurred in SK-N-ASCis24 cells (see Figure 1).

nbl-cells

Figure 1. Microscopic images sensitive and drug resistant neuroblastoma cells (adapted from (2)) 

Two drug resistant cell lines SK-N-ASCis24 and CHP212Cis100 cells developed additional mobility skills – they became more invasive than their parental counterparts.

 

resistant-cells

 

Then we asked a question: what type of changes allowed cells to adapt to cytotoxic environment?  We examined changes in their genomic DNA first. We found that some genes increased their copy number, other went missing.

We identified changes in protein expression. More intriguingly, some proteins with the increased presence in the cells did not increase their presence in genomic DNA. We sorted these proteins on their role in cell processes such as migration, growth, cell cycle, etc. We found that each cisplatin resistant cell line developed a unique set of features that help them to escape cytotoxic stress (2). The similar patterns are found in clinic. Each patient responds to treatment differently.

What did we learn from this study?

  • One drug, in our study cisplatin, can activate the cell defense systems that allow to escape toxicity of other drugs.
  • The development of drug resistance gives cells new advantages and changes their behaviour and appearance, e.g. mobility skills, different cell shape, response to drugs, etc.
  • Each cisplatin resistant cell line developed a unique set of features that help them to escape cytotoxic stress.
  • These cell lines can be used to test new drugs and find those that can overcome developed resistance.

References

  1. Davidoff AM. Neuroblastoma. Semin Pediatr Surg. 2012; 21(1):2–14.
  2. Piskareva O, Harvey H, Nolan J, Conlon R, Alcock L, Buckley P, et al. The development of cisplatin resistance in neuroblastoma is accompanied by epithelial to mesenchymal transition in vitro. Cancer Lett. 2015;364(2):142–55.