How often do you moisturize your skin? Every day? Once a month? Well researchers at Northwestern University in Chicago have given a moisturizer the ability to perform RNA interference and regulate genes.

Topical treatments are common for skin cancers like melanoma, as they can be applied directly to the affected cells. But our skin is very effective at blocking toxins getting into our bodies so the challenge was how to cross that barrier.

Again, enter the realm of nanotechnology, a topic I post about regularly.

This time, the scientists paired gold nanoparticles with small interfering RNA (siRNA) molecules to form a siRNA “sphere.” These miniscule balls were able to penetrate skin cells, and then the specifically-designed siRNA was able to effectively switch off the EGFR gene that codes for the epidermal growth factor receptor protein. EGFR is one of the crucial proteins in pathways to cancer, and can cause cancer cells to go into overdrive and proliferate.

The key factor was the sphere shape, concentrating the nucleic acid in the RNA. Linear nucleic acids can’t get into cells, but spherical ones can.

So what miraculous moisturizer did they use? La Mer? Clinique? Something mixed up in a special laboratory? Nope. They used a cheap, readily available moisturizer.

This type of breakthrough is yet another example of the brilliant strides science can make when one discipline talks to another. In this case, dermatology, cancer and chemistry came together under the remit of the Skin Disease Cancer Research Center at the Feinberg School of Medicine at Northwestern.

Different cell type (skin cells, neurons, osteoblasts, etc.) start out from less specialized cells, called stem cells. What a cell will become (its characteristics and functions) is also known as the cell’s “fate.” It may seem odd that seemingly simple skin cells can be transformed into cells that make up the thinking brain. However, all cells have a common set of DNA instructions, and it is the collection of instructions that are being actively “read” that determine what fate a cell well adopt.

In this study, two microRNAs (miR-9/9* and miR-124) were introduced into the fibroblasts. These micro RNAs then go on to alter the expression of their target genes. While RNAi can have very specific effects when there is only one target gene, in this case the micro RNAs targeted a set of genes that had global effects on which set of DNA instructions were being carried out by the cell through a process called chromatin remodeling.

Chromatin (the proteins involved in packaging DNA) determines which genes can be read by the cell, and which genes are hidden (unreadable) by the cells. Since microRNAs miR-9/9* and miR-124 act on a system of proteins (the SWI/SNF-like BAF chromatin remodeling complex) these 2 microRNAs have a greatly amplified effect on many sets of genes that are neuron specific.

Unlike other cell types which are easily collected, neuronal cells (especially in specific clinically relevant contexts) are hard to come by. Being able to create neuronal cells in a “one step” process (vs. previous research methods which could transform skin cells to neuronal cells via an intermediate stem cell step) is an advance that has great potential to speed up neuroscience research.