Tag: #neuroblastoma

#JournalClubwithRonja: Reaping the benefits of PhDs past

It’s the second round of journal club blog posts, and this time around, we’ll be looking at papers published by this very lab. I’ll be focussing on the paper in which the cell line I am currently working with (KellyCis83) was developed: “The development of cisplatin resistance in neuroblastoma is accompanied by epithelial to mesenchymal transition in vitro” This research addresses a critical challenge in cancer treatment: drug resistance, of course focusing on neuroblastoma, pediatric cancer notorious for its aggressive nature and poor prognosis that this lab has been studying for years.

Neuroblastoma is typically treated with cisplatin, a potent chemotherapy drug that induces DNA damage in cancer cells, leading to their death. The issue is that over time and particularly during relapse, some neuroblastoma cells develop resistance to cisplatin, rendering the treatment ineffective. Understanding the mechanisms behind this resistance is crucial for developing new therapeutic strategies.

In this study, neuroblastoma cell lines resistant to cisplatin were created by gradually exposing the cells to increasing drug concentrations over 6 months. This approach mimics the clinical scenario where tumours are exposed to chemotherapy over an extended period, eventually leading to resistance. The resistant cell lines were then characterized to uncover the molecular changes that had occurred alongside or as part of the increased drug-resistance.

The cisplatin-resistant neuroblastoma cells exhibited significant disruptions in their cell cycle regulation, as highlighted by the most altered pathways identified by mass spectrometry. Cisplatin typically causes DNA damage that halts the cell cycle, leading to cell death. However, the researchers found upregulated pathways in resistant cells that allowed these cells to bypass this damage-induced arrest. One key finding was the identification of Vimentin upregulation in the upstream regulator analysis. Vimentin is a marker typically associated with epithelial-to-mesenchymal transition (EMT).

EMT is a process where epithelial cells acquire mesenchymal, fibroblast-like properties, including enhanced motility and apoptosis resistance. The link between EMT and cancer progression is well-established, as EMT not only facilitates metastasis but also contributes to drug resistance. In the context of neuroblastoma, the upregulation of Vimentin and dysregulation of related EMT proteins found in two of the resistant cell lines (specifically SNAI1 and TWIST1) suggests that these cells are not only evading cisplatin-induced cell cycle arrest but are also acquiring more aggressive, invasive characteristics. This links back to their findings on invasiveness, which showed greater levels in the two resistant cell lines that also had greater changes in EMT-related proteins (Figure 1).

Figure 1 A Relative invasiveness of the parental cell lines compared to the cisplatin resistant daughter cell lines.  Graphed data represent mean values ± SD of three independent experiments. Asterisks indicate statistical significance obtained using a paired Student’s t-test. * p < 0.05, ** p < 0.01, ***p < 0.001, n = 3 for all experiments. B The fold change in protein expression of drug resistant cells compared to their parental counterparts was quantified by densitometric analysis of two biological repeat experiments, normalised against endogenous control ACTB. (Adapted from (Piskareva et al., 2015).

Understanding the role of EMT in cisplatin-resistance opens up new avenues for therapeutic intervention. Targeting EMT-related pathways Vimentin could potentially restore the sensitivity of these resistant neuroblastoma cells to cisplatin, by targeting the evasive mechanisms the cells developed to bypass the cell-cycle disruption. Such therapies would offer a new strategy to tackle drug-resistant relapse cases, which currently have very poor outcomes.

Overall, this study provides a valuable model for investigating drug resistance in neuroblastoma and highlights the crucial role of EMT and its associated pathways in finding ways to treat drug-resistant tumours. As we continue to explore these avenues, these models will serve us as a strong foundation facilitating the research currently taking place in our lab towards finding such combination therapies and hopefully improving outcomes for children battling this devastating cancer in the future.

Written By Ronja Struck

September – Childhood Cancer Awareness Month, 2024

Cancer is the 2nd most common cause of death among children after accidents. 

Childhood cancer is an umbrella term for many other types of this disease. Every September, many charities, researchers and parents of children with cancer work hard to raise awareness of this cancer. You may learn more about kids with cancer, their loving families, the doctors and caregivers who look after them and treat them, the young survivors of cancer and those kids and teens who lost their battle, and the scientists who work hard to find a way to stop childhood cancer.

This year, our research team will run the Pub Quiz on September 18th, 2024, in honour of Childhood Cancer Awareness Month. All donations will go to the Conor Foley Neuroblastoma Research Foundation (CFNRF).

If you would like to get involved in this amazing challenge and help us raise vital funds for childhood cancers, you can contribute to our fundraising page:

#JournalClubwithRabia: How Can Fish Help Us Study Anticancer Drugs?

Hi all! Rabia here, I came across an intriguing paper highly relevant to my work on the rapid in vivo validation of HDAC inhibitor-based treatments using neuroblastoma zebrafish xenografts. The study outlines a zebrafish neuroblastoma yolk sac model specifically designed to evaluate both the effectiveness and toxicity of histone deacetylase (HDAC) inhibitors.

HDAC inhibitors are drugs that target specific enzymes involved in gene regulation. This study tested broad-spectrum HDAC inhibitors as standalone treatments and combined them with doxorubicin, a well-known chemotherapy drug.

But why on Zebrafish? The zebrafish model provides a rapid and efficient means of testing these treatments, offering valuable insights into their potential use in combating neuroblastoma. This model allows for assessing drug efficacy and helps understand the associated toxicities quickly, making it a powerful tool for developing new anti-cancer therapies.

In the study, fish larvae were implanted with fluorescently labelled, well-established neuroblastoma cell line (SK-N-BE(2)-C) and patient samples (HD-N33, NB-S-124) to grow tumours. Non-cancerous cells (VH7 fibroblasts) were utilized to verify that tumour progression in zebrafish was specific to tumour cells. The engraftment of human cells into fish larvae was confirmed by immunohistochemistry (IHC) staining on zebrafish sections injected with neuroblastoma cells (SK-N-BE). This was achieved using a STEM121 antibody that reacts specifically with a human cytoplasmic protein. The findings showed that pediatric tumour cells survive and grow in the zebrafish model at rates like those observed in human tumours.

Before testing drug efficacy in zebrafish xenografts, optimal drug concentrations and maximal tolerated doses (MTD) were determined. Toxicity tests were conducted by treating fish larvae cells for three days without tumour cell injection to identify the maximum tolerated dose that did not cause observable morbidity, changes in morphology, or severe aberrations in larval behaviour. and lethal dose (LD) for each compound. To find optimal drug concentrations, larvae with xenografted tumour cells were incubated with increasing drug doses 24 hours post-implantation to the maximally tolerated dose (MTD). The relative IC50 values were then determined based on changes in tumour mass volume.

To evaluate the treatment, SK-N-BE(2)- cells were used to test the broad-spectrum HDAC inhibitors, including panobinostat, vorinostat, and tubastatin A, both alone and combined with doxorubicin. The partial response rate (PR) was measured to see how well different drug combinations work to shrink tumours in the zebrafish model. Here’s what they found: Doxorubicin combined with panobinostat resulted in a 23% PR, Doxorubicin combined with tubastatin A showed a 31% PR, and Doxorubicin combined with vorinostat achieved the best result with a 36% PR.

To test the effectiveness of the HDAC inhibitor treatment, they monitored the tumour growth using a confocal microscope before and 48 hours after giving the drug. The test revealed that a 48-hour treatment of SK-N-BE (2)-C zebrafish xenografts with vorinostat and doxorubicin alone, `and in combination, increased cell death. The combination of these two drugs was the most effective, causing a significant increase in cancer cell death (apoptosis) by decreasing cell proliferation, as indicated by reduced PPH3 marker and activating the number of Cleaved caspase-3 (Figure 1).

Figure 1: Treatment for 48 h with Vorinostat, doxorubicin, or a combination of both increased the amount of cleaved caspase-3 and reduced mitotic tumour cells. Adapted from Pharmaceuticals 2020, 13(11), 345

In essence, this study validates the use of HDAC inhibitors in treating neuroblastoma and paves the way for broader applications of zebrafish models in cancer research. As we look to the future, these innovative models could significantly enhance our ability to develop effective cancer therapies, making strides towards better treatments and, ultimately, more effective cures.

Written by Rabia Saleem

#JournalClub: Anti-Cancer Immunotherapy

Hi there, Federica here! In the fast-paced world of scientific research, staying informed about the latest studies and breakthroughs is crucial. It enables researchers to build upon existing knowledge, avoid redundant efforts, and discover new directions for their work. That’s why we’ve started a new series of blog posts highlighting recent papers and explaining their significance for our research.

Recently, a fascinating study explored an innovative method to boost the effectiveness of cancer immunotherapy: “A combination of a TLR7/8 agonist and an epigenetic inhibitor suppresses triple-negative breast cancer through triggering anti-tumour immune“.

The researchers investigated a combination of immune checkpoint blockade (ICB) and other drugs to turn “immune-cold” tumours (which evade the immune system) into “immune-hot” tumours (which the immune system can attack). They developed a special delivery system using nanoparticles called metal-organic frameworks (MOFs). These nanoparticles were loaded with two types of drugs—a TLR7/8 agonist and an epigenetic inhibitor (BRD4 inhibitor). To make the nanoparticles even more effective, they were coated with vesicles from the cancer cells themselves. This coating helps the nanoparticles specifically target cancer cells.

But how does it work?

The nanoparticles are designed to find and enter triple-negative breast cancer (TNBC) cells. Once inside, the drugs prompt the cancer cells to break apart and release signals that alert the immune system. These signals attract dendritic cells, which then activate CD8+ T cells—the body’s natural cancer fighters. The TLR7/8 agonist further enhances this immune response, making the treatment more powerful.

In both laboratory tests and animal models, this method showed significant promise. It not only slowed down tumour growth but also improved the body’s immune response to cancer. Importantly, the study found that this approach could remodel the tumour environment, making it more hostile to cancer cells. For example, they wanted to verify that their combined delivery system could really boost the body’s ability to fight tumours. They focused on a protein called calreticulin (CRT) that, when it shows up on the surface of tumour cells, helps the immune system spot and remove them. They found that when they used their special delivery system (CM@UN and MCM@UN), the levels of CRT on the surface of tumour cells went way up. This was especially true for the MCM@UN group, showing just how powerful their method was in getting the immune system to attack the tumours.

The original image was published in J Nanobiotechnology. 2024; 22: 296.

So, why is this study important for my work?

The principles of enhancing the immune system’s ability to fight cancer are central to both the research in the study and in my project. Like the nanoparticles in the study, mRNA vaccines can be designed to specifically target cancer cells, ensuring that the treatment reaches its intended destination. Another similarity is how the drugs activate the immune system, which parallels how mRNA vaccines work—by training the immune system to recognise and attack cancer cells.

I find this study really interesting as it sheds light on innovative strategies for cancer treatment and provides valuable insights that can inform and inspire our research on developing mRNA vaccines for childhood neuroblastoma!

Written by Federica Cottone

Class 2024: Congratulations to Ciara, Ellen and Rabia!

Massive congratulations on the official moulding of PhD and MSc by Research to our promising young scientists: Rabia Saleem, Dr Ciara Gallagher and Dr Ellen King! Great accomplishments!

Three different journeys, with two through the COVID-19 pandemic. The full range of ups and downs. Who said that the PhD is a straight line? It has never been. It is more like the Irish weather: some days are sunny and bright, and some have scattered showers, gale winds and stormy snow, with sunshine developing elsewhere. The journey was spiced up with publications, conferences, travels, days out and fundraising events with the team.

It is a proud moment for me as well. 🙂 Three PhD and one MSc by Research students graduated within the last 12 months.

Of note, Ellen was behind our Twitter activities in the past, making our team visible!

Wish you all the best of luck on your new adventure!

Olga Piskareva

Congratulations to a new Dr in the house: Dr Ellen King

Huge congrats to a newly minted Dr Ellen King!  She passed her PhD viva on April 9. This is a testimony to your dedication, strong will and hard work. May this PhD be the beginning of many more successful endeavours, Ellen!

We thank examiners Prof Sally-Ann Cryan (RCSI) and Prof Joanne Lysaght (TCD) for the time and expertise they provided.

We also thank the RCSI PhD Programme for their generous support!

From left to right: Prof Joanne Lysaght, Dr Ellen King, Dr Olga Piskareva & Prof Sally-Ann Cryan

How things work in science: targeting cell components.

How do researchers study cells? How do we get the nitty gritty?

We use many methods to tag and chase various cell components. One of my favourites is fluorescent microscopy. It allows the use of nearly all spectrum of colours from blue to purple in one go. However, we prefer to narrow it down to 2-3 colours and avoid their overlap.

How does it work? First, we use DAPI or Hoescht, which are blue fluorescent dyes used to stain DNA. This way, we tag the nucleus of the cell. Then, we tag a protein of interest. In our case, it was MYCN, a protein that acts as a transcription factor. MYCN amplification is associated with poor prognosis in neuroblastoma. As a transcription factor, it binds to genomic DNA and is located in the nucleus. We used a specific antibody that was labelled with a green fluorescent dye. Look at the image below. The green colour pattern overlaps with the blue colour. Then, we tagged the cytoskeleton, a complex of various proteins that hold the cell architecture and dynamics. We used phalloidin with red fluorescence. It is a highly selective bicyclic peptide and a popular choice for staining actin filaments.

Neuroblastoma organoids stained with DAPI, Phalloidin and anti-MYCN antibody. This work was done during the Fulbright journey to Ewald’s Lab at Johns Hopkins

Now, we can enjoy visualising cells and test different research questions. For example, how do cells respond to a drug? Or how do neuroblastoma cells spread?

Written by Olga Piskareva

How things work in Science: Tìr na nÒg

In humans, NANOG, SOX2, and OCT4 are transcription factors that maintain the undifferentiated state of embryonic stem cells (ESCs). NANOG was first discovered in 2003 by Chambers et al. and Mitsui et al. as a transcription factor in ESCs responsible for cellular self-renewal. More importantly, it enables continuous self-renewal of cancer stem cells, leading to metastasis when the regulatory genes involved do not function normally. These have been identified as cancer stem cells, with NANOG being a marker of “stemness”. In multiple cancer types, NANOG has various effects, including cellular expression of mesenchymal phenotype, cellular invasion/migration, repressed apoptosis, drug resistance, and increased angiogenesis. In pathways, NANOG either promotes or represses the expression of other genes that lead to cancer-favoured cellular behaviour. Overall, a higher expression level of NANOG is usually indicated in cases of poor prognosis.

NANOG is even more interesting due to its eponym, which comes from Tìr na nÒg. A Celtic myth of the Land of Youth, where the Tuath Dé resided in a supernatural land of paradise. This land offered beauty, health, joy, and everlasting youth to the inhabitants. As the myth goes, the Tuath Dé were gods of the land, and the god that ruled, Manannán mac Lir, was the first ancestor of humans. In various Celtic legends, humans are invited by the gods to visit Tìr na nÒg on great adventures.

However, time passes much slower in Tìr na nÒg, making it precarious for humans to return to their own world. As is the fateful tale of Oisín, who fell in love with the Tìr na nÒg goddess, Niamh. He travelled with her to Tìr na nÒg, where they lived happily in paradise. Upon a visit back to Ireland, Oisín realized that all his family had died over the years. When Oisín found a group of men who were struggling to move a giant rock, he stopped to lend them a hand while on his horse. However, the weight of the rock caused his saddle strap to snap. He fell from his horse, and when he touched the ground, he suddenly aged 300 years all at once.

Written by Alysia Scott

Sources:

Gawlik-Rzemieniewska, Natalia, and Ilona Bednarek. “The role of NANOG transcriptional factor in the development of malignant phenotype of cancer cells.” Cancer biology & therapy vol. 17,1 (2016): 1-10.

“The Story of Tír Na NÓg.” Celtic Titles, 10 Feb. 2022

Congratulations to Dr Ciara Gallagher!


Huge congrats to a newly minted Dr Ciara Gallagher!  She defended her PhD on March 8 – International Women’s Day. Your enthusiasm and perseverance are truly fascinating! May this be the stepping stone towards a brighter future, Ciara!

We thank examiners Dr Marie McIlroy (RCSI) and Prof Jan Škoda (Masaryk Uni) for the time and expertise they provided.

We also thank the Irish Research Council for their generous support!

Dr Ciara Murphy (Chair), Dr Olga Piskareva (Supervisor), Dr Ciara Gallagher, Prof Jan Skoda (examiner), Dr Marie McIlroy (Examiner)

Ever wonder how scientists figure out a specific protein’s role in cancer?

Researchers use various methods, but I employ gene knockdown in my experiments. Basically, I use small RNA molecules that specifically target and degrade the mRNA of my gene of interest. This leads to a decrease in the corresponding protein levels, enabling me to observe the effects on neuroblastoma cell behaviour.

I feel a bit like Sherlock Holmes, you know? I’m selectively putting my suspect protein – the one I’m eyeing – under the spotlight to see how it’s pulling the strings on the cell’s behaviour. It’s like I’m in a cellular mystery, complete with a gene knockout magnifying glass 🔍🧬🕵

So, what I’ve been up to these past months is knocking down my protein and trying to find answers to the following questions:

Can neuroblastoma cells survive? And if not, how do they meet their demise? Do they go on a growth spree and start proliferating? Are they capable of migration? And here’s the twist – when my protein of interest takes a dip, do other proteins decide to change their expression levels?

The picture below can probably help you get an idea of what I’ve done so far. Do you see those brighter spots in Pictures A and B? Those are dead cells. Their number indicates the proportion of dead cells after a treatment. Picture A has just a few; the majority are healthy and well-spread cells. This is our negative control, a condition when we show neuroblastoma cells that have been transfected, but no gene knockdown happened. Transfection is the term for introducing small RNA molecules. Now, in Picture B, when we knocked down the protein, it caused the death of the cells, and you can clearly see that from all those many little bright spots.

We have found answers to many of the previous questions, but new questions have arisen, and we can’t wait to answer them!

Written by Federica Cottone