Small but Mighty: The Role of MicroRNAs in the War against Cancer - by Guest Writer, Josie Crisp

Altering the essential building blocks of living organisms, MicroRNAs can perpetuate the progression of cancer but also have potential as exciting and novel treatments to suppress tumour development.

Cancer is the leading cause of death worldwide, and identification of potential life-saving treatments is at the forefront of scientific research. The World Health Organization states that early tumour detection and cancer screening of at-risk populations is crucial for patient survival. Availability of a biomarker, which holds the molecular signature for each cancer variant, would be fundamental to promoting improved care.

DNA, an essential building block of living organisms, must be strictly regulated as genetic mutations can result in various diseases. Similarly, RNA is also vital to life. MicroRNAs (miRNAs), a sub-group of RNA molecules, can alter other human genes and control protein transcription. miRNAs are required for normal human function, but when interrupted can influence normal gene function and perpetuate the expression and progression of cancerous cells.

miRNAs are specific to tumour type, may be detected in the blood, and have the potential to provide a simple, accurate and non-invasive biomarker test for diagnostic and prognostic purposes. Thus, miRNAs may become fundamental to the future of cancer treatment.

In cases where miRNAs facilitate cancer development, the application of miRNA inhibitors or mimics have the potential to reverse such activity. Preclinical studies suggest that inhibitors could impede the miRNAs that promote cancer development, and mimics may simulate the effects of tumour suppressing miRNAs.

Currently, delivery of miRNA-corrector therapeutics is a perplexing issue. miRNAs do not just target one gene but are able to modify multiple genes simultaneously. Therefore, if the tumour is not targeted directly, there may be serious genetic repercussions. To navigate such events, research is investigating miRNA packaging and delivery. miRNAs enveloped within viruses have demonstrated positive outcomes in animal research; translation into humans is expected to cause wider issues with immune responses. Subsequently, focus has shifted towards nanoparticles, whereby miRNA-correctors could be delivered directly to a tumour inside a tiny submarine-like package.

This is an exciting time for cancer research and personalised medicine, with the hope of one day rendering invasive cancer therapies unnecessary.