Research showcased at MLSFF shows drugs impacting gene expression could treat rare childhood cancer
A rare cancer that affects children could potentially be treated with drugs that limit the expression of a cancer-linked gene, according to new research that will be showcased at MLS Future Forum later this month.
The research, by Shalom Ndofula, an undergraduate at Birmingham City University, will be highlighted at the Minoritised Life Scientists Future Forum (MLSFF26) at Edinburgh International Conference Centre from March 23 to 25.
MLSFF26 is the only major conference in Europe dedicated to supporting and showcasing the contributions of marginalised and underrepresented communities in the life sciences and is expected to attract hundreds of scientists to Edinburgh. With the city’s remarkable history of scientific invention and discovery, it’s the ideal location for young scientists to share their own breakthroughs.
Shalom explained that MYCN, a proto-oncogene, is overexpressed in high-risk neuroblastoma (NB) and is linked to poor prognosis. Her research has found that treating CHLA-20 neuroblastoma cells with the epigenetic drugs Nanaomycin A and BI-2536 reduced the expression level of MYCN.
“High-risk neuroblastoma is responsible for majority of childhood cancer deaths. It is a very aggressive form of the disease, has a low survival rate in most cases, and is difficult to treat, she said.
“A contributing factor is MYCN, a proto-oncogene which is normally involved in important biological processes like cell differentiation, proliferation and apoptosis (programmed cell death). However, MYCN overamplification is found in high-risk cases of neuroblastoma. It also seems to lead to tumour suppressor gene silencing through hypermethylation, allowing the cancer cells to proliferate uncontrollably.
“The drugs Nanaomycin A and BI-2536 have the potential to mitigate this through epigenetic changes, but there is limited research that characterises their effects on MYCN.”
Nanaomycin A is an antibiotic that inhibits DNA methyltransferase 3B (DNMT3B), an enzyme involved in de novo methylation. Thus, it may have some effect on MYCN through downstream mechanisms that cause the gene to become hypermethylated, Shalom explained.
Meanwhile, BI-2536 is a drug that inhibits the enzyme polo-like kinase 1 (PLK1), which promotes cell cycle progression from G2 to mitosis, where cell division occurs. PLK1 has been shown to stabilise MYCN, so its inhibition may induce a cellular stress response leading to cell death in neuroblastoma.
“My project aimed to investigate and characterise the response of neuroblastoma cells, specifically the CHLA-20 lines, to the Nanaomycin A and BI-2536 treatments. I specifically looked at the expression levels of MYCN, and Bax as a cell death/apoptosis marker,” Shalom said.
She first treated CHLA-20 neuroblastoma cells with 1nM of either Nanaomycin A or BI-2536 for 24 hours. Untreated CHLA-20 cells were used as a control for comparison. Afterwards, RNA was extracted from the samples and assessed for quality and quantity, before cDNA was synthesised using oligoDT18 primers. These specific primers were chosen to reverse transcribe mRNA. cDNA was then used as a template for the PCR and quantitative PCR (qPCR) experiments.
PCR was carried out using MYCN and Bax specific primers, with β-actin as a housekeeping gene control. The primers have been designed and confirmed by using the NCBI Primer-BLAST tool.
Next, qPCR was used to quantify the expression levels of MYCN, Bax and β-actin. The fold change expression of MYCN and Bax was then calculated using the 2^-ΔΔCt formula.
“The fold change expression showed a downregulation of MYCN in CHLA-20 cells treated with Nanaomycin A, and BI-2536. This suggests that both drugs may be effective to treat the overexpression of MYCN in NB,” Shalom said.
“One surprise was that Bax expression levels, the apoptosis marker, were also downregulated in CHLA-20 cells that received the drug treatment.
“I thought there would be an upregulation of Bax, indicating some induced cell death. However, apoptosis could not be confirmed from this result alone, leaving room to investigate whether it occurred, or was mediated through another pathway, i.e. non-intrinsically or post-translationally.”
Shalom’s findings would mean that epigenetic drugs may potentially be used to treat NB with MYCN overexpression. The downregulation of MYCN could restore normal cell function and increase the likelihood for recovery of high-risk NB.
“The effect of epigenetic drug treatment has to be confirmed for other NB cell lines. Also, downstream mechanisms that lead to MYCN downregulation have to be characterised. Since induction of apoptosis could not be confirmed in CHLA-20 cells, additional cell death markers should be used to exclude or confirm apoptosis.”
The study was led by project supervisor Dr. Irmgard (Irmi) Haussmann, and supported by Birmingham City University. “I am so thankful for Irmi’s guidance throughout my research project!” Shalom said.
Find out more about MLS Future Forum HERE.
For more information about MLSFF26 or to arrange interviews with members of the steering committee, contact [email protected].
