With the help of our supporters, the Melanoma Fund was able to support a melanoma microRNA biomarker project, run by the Brighton and Sussex Medical School and headed up by Prof. Sarah Newbury. We have been work closely with the team and here is their final report.
By Professor Sarah Newbury, Brighton and Sussex Medical School (BSMS)
Melanoma remains the most aggressive form of skin cancer with an increasing incidence worldwide. Survival rates depend heavily on the stage of disease at the time of diagnosis. When detected in the early non-metastatic stages (I and II), melanoma has good prognosis with a 5-year survival rate of ~100% in stage I melanoma patients and 80%-90% in stage II melanoma patients, as thin local tumours are highly curable by surgery.
Unfortunately, recurrence is common and often results in progression to locally advanced melanoma and subsequently to metastatic melanoma (stages III and IV), with a 5 year survival rate of ~50% in stage III melanoma patients and 10-25% in stage IV melanoma patients. Therefore there is a pressing need to establish robust biomarkers that allow the identification of patients at high risk of metastatic recurrence after surgical removal of a non-metastatic melanoma.
Early detection will maximise the chances of patient survival, as there are now a number of treatment options available that are effective against certain subtypes of stages I, II and III melanoma.
Circulating microRNAs are emerging as promising non-invasive cancer biomarkers that can be detected from a blood sample. MicroRNAs are small non-coding nucleic acids that function in gene silencing and are often associated with cancer progression.
These microRNAs are stable in the circulating blood because they are encapsulated in small vesicles (exosomes) or are bound to protective proteins. Previous work carried out at the Blond McIndoe Research Foundation and the Brighton and Sussex Medical School identified 3 potential microRNA biomarkers that can distinguish Stage I/II from Stage III/IV melanoma, plus three potential reference controls.
Support from the Melanoma Fund
Generous funding from the Melanoma Fund provided us with the exciting opportunity to check and validate the microRNA biomarkers identified in these initial experiments. The technician employed on the grant, Sophie Mumford, used the serum of 20 healthy, 20 melanoma stage I/II and 20 melanoma stage III/IV donors, which were originally collected at the Queen Victoria Hospital, East Grinstead.
Sophie performed 2,034 careful experiments to validate these 3 potential biomarkers and 3 reference controls as well as checking 2 new potential biomarkers identified following the re-analysis of the original data and evaluating the effect of different extraction kits and experimental conditions.
Sadly, despite all this careful experimentation, we have not found any microRNA biomarkers which clearly and consistently distinguish between non-metastatic and metastatic melanoma. We are all deeply disappointed with this result. The circulating microRNA biomarker field is still in its infancy; therefore techniques are difficult and are not yet well established.
The techniques being used to detect microRNA biomarkers in serum have improved immensely since the start of this project and continue to improve, therefore if we started this project again, we would have much more likelihood of success. With this is mind, we thought that it would be very useful to provide an up-to-date review of the literature on circulating miRNA biomarkers in melanoma, using our experience to focus on the pre-analytical and analytical variables that challenge this field.
Interestingly, none of prognostic melanoma microRNA biomarkers published have used the rigorous normalisation procedures that are now required in the field. Therefore there are, as yet, no reliable circulating microRNA biomarkers which can distinguish metastatic from non-metastatic melanoma.
Despite our difficulties in identifying microRNA biomarkers for melanoma this time, we have been successful in providing a number of outputs for the Melanoma Fund. These include our monthly reports, invitations to speak at International Conferences, poster presentations at International conferences, grants and training.
These outputs are detailed below:
2013-2015: £20,000 for a BBSRC “Sparking Impact” Award to fund a post-doc, consumables, patent searches and market surveys. Title of project “Investigating the potential of microRNAs as biomarkers in malignant melanoma.”
2016-2017: £75,588 from Cancer Research UK (through the Experimental Cancer Medicines Centres “ECMC” Network) for a project over four centres (Universities of Leeds, Sussex, Cambridge and Newcastle on a project entitled “Standardisation of analysis and reporting of miRNA biomarkers in plasma from circulating blood. £17,896 (Co-PI: 24%) per centre, with Prof. Sue Burchill (Principal Applicant (28%), University of Leeds).
2017: £1395 from the University of Sussex Research Opportunities Fund to support two “Research Strengths in Cancer” Workshops. (Co-applicants: Dr George Giamas (University of Sussex) and Dr Mel Flint (University of Brighton)).
Presentation of research at International Conferences:
Smalley, S., Gilleard, O., Aspden, J., Pacifico, M., Banwell, P., Metcalfe, A.D., Newbury, S.F. and Martin, Y. microRNAs as biomarkers for melanoma. Translation UK, Leicester, July 2014. Poster presentation.
Smalley, S., Gilleard, O., Aspden, J., Pacifico, M., Banwell, P., Metcalfe, A.D., Newbury, S.F. and Martin, Y. (2014) microRNAs as prognostic biomarkers for melanoma progression. Poster presented at the conference Non-coding RNA – From basic mechanisms to cancer, Heidelberg, Germany, June 2014. Poster presentation.
Smalley, S., Gilleard, O., Aspden, J., Pacifico, M., Banwell, P., Metcalfe, A.D., Martin, Y. and Newbury, S.F microRNAs as prognostic biomarkers for melanoma progression. BSMS Integrated Health Care Research Day. November 2014. Poster presentation.
Jones, C.I., Zabolotskaya, M.V., Smalley, S.K., Pashler, A.L., Caserta, S., Gilleard, O., Pacifico, M., Metcalfe, A.D., Martin, Y. and Newbury, S.F. “Identification of microRNAs for use as prognostic biomarkers in myeloma, melanoma and sepsis.” Circulating biomarkers 2015 Glasgow conference. Glasgow, UK. October 2015. Poster presentation.
Invitations to give research talks at International conferences
March 2016: Invited to present our work on microRNA biomarkers at BSMS to the Health and Life Sciences Networking Event (10/3/16). This has led to a number of new links with Industrialists who are likely to be helpful in facilitating Industrial funding.
October 2016: Invited by the conference organiser, Dr Ed Quazi, to be a guest speaker at the Circulating Biomarkers conference at Abertay University, Dundee, Scotland.
February, 2018: Invited by the conference organiser, Cerlin Roberts of Oxford Global, to be a guest speaker at the 13th Annual Biomarkers Congress in Manchester, UK.
Sophie Mumford has increased her expertise in the cancer biomarker field and is eager to continue her work in Cancer Research by carrying out a Ph.D.
Sarah Smalley increased her expertise in analysis of circulating biomarkers in melanoma and is now working in a Biomarkers company in the U.S.A.
Amy Pashler increased her expertise in analysis of circulating biomarkers in melanoma and is now completing her PhD in cancer.
Five reports detailing the progress on our work.
Burchill, S., Droop, A., Jones, C. I., Brownhill, S., Amankwatia, E., Prokoph, N. Viprey, V., Thorne, J., Hughes, T., Towler, B.P., Pashler, A., Murray, M., Greystoke, A. and Newbury, S.F. A systematic review of the methodologies used in the detection and analysis in circulating microRNAs in cancer: recommendations for good practice. Nature methods (in prep).
Mumford, S., Towler, B.P., Pashler, A.L., Gilleard, O., Metcalfe, A.D., Martin, Y. and Newbury, S.F. Circulating microRNA biomarkers in melanoma: tools and challenges in personalised medicine. (to be submitted to Biomolecules)