Blog about neuroblastoma research
My WordPress Blog is about neuroblastoma biology and Cancer Bioengineering Group
The research is a long-term investment. It is always built up on the work of the predecessors. Keep research running is crucial to make the dreams come true. Dreams for better treatment options and quality of life.
Thank you to everyone involved in raising funds for CMRF!
CMRF Spring Newsletter can be found here – CMRF-Spring Newsletter Final 15.05.17
A Research Project Grant funded by National Children’s Research Centre will be starting in April.
The ultimate aim is to identify biomarkers of tumour response to drugs in the blood of children with high-risk neuroblastoma.
Challenge: Treatment regimens for patients with high-risk neuroblastoma involve intensive, multi-modal chemotherapy. Many patients response to initial therapy very well, but has only short-term effects, with most becoming resistant to treatment and developing progressive disease.
The project has two parts which complement each other.
Part 1
Part 2
How does this project contribute to the biomedical community?
This study aims to contribute to the better understanding of the disease mechanisms and scientific knowledge in the area, and in particular how neuroblastoma cells communicate with other cells helping tumour to create a unique microenvironment and protect themselves from chemotherapy pressure. The new data will give insights in biologically active proteins and miRNAs involved in cell-to-cell communication and drug responsiveness.
What are potential benefits of the proposed research to neuroblastoma patients?
This project aims to develop exosomal biomarkers of tumour response to drugs that might be used to help select patients for treatment and identify novel targets for the development of more effective personalised therapy with the anticipated improvement in outcomes. This work will contribute to the more efficient design of re-initiation treatment, sparing patients unnecessary rounds of chemotherapy and ultimately increasing survival. These new circulating markers will benefit children with high-risk neuroblastoma whose tumours are relapsed leading to less harmful and more tailored treatment options and improving their quality of life.
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.
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.
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.
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.
Recommended reading
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).
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.
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?
References