A review of the current state of Hair Cloning and Tissue Engineering research, written by Dr. Jerry Cooley. We also have a complete abstract from the October ISHRS conference covering yet another step forward in conquering this technology…The following excerpt was used with permission. Below the excerpt is the full abstract on the latest research presented at the ISHRS conference on hair cloning.
Dr. Jerry Cooley
The possibility of creating a large number of hair follicles from a single hair follicle is sometimes inaccurately referred to as “hair follicle cloning”. The term cloning is used by scientists to refer to the technique where genes are inserted into a cell, and the daughter cells all have the same gene. Genes are sequences of DNA which code for a particular protein necessary for the proper functioning of the cells of our bodies. For example, an individual gene for protein X may be inserted into a cell. The daughter cells of this original cell will all produce the same protein X. We then say we have ‘cloned’ that gene. An extension of this technique is to not just take one gene, but all the genes which make up an organism and insert these into an embryonic cell which subsequently develops into an exact replica of the original organism. The most famous example of this technique is ‘Dolly’, the cloned lamb, who burst on the international scene in 1996.
The mechanism where a single hair follicle could be turned into hundreds or thousands of hair follicles is not ‘cloning’ but tissue engineering or what is sometimes called cell therapy. This technique does not involve the insertion of particular genes but works at a higher level, the cell. Cells are the basic building blocks of life. The number of cells in an organism varies from the one-celled viruses and bacteria to humans which are composed of billions of cells.
Cells can be isolated from an organism and then can be grown in the laboratory by keeping the cells bathed in special medium (culture medium) and controlling the amount of oxygen and other gases around the cells. Cell therapy consists of taking these cultured cells and placing them into a patient to correct a particular condition. Cell therapy is one of the most exciting areas of medical research today. Conditions which are or will be treated by cell therapy include skin ulcers and burns, arthritis, diabetes, cancer, Parkinson’s Disease, liver failure, to name a few. It does not take a big stretch of the imagination to see how this idea could be used to treat hair loss. Nor is it surprising that several research groups around the world are actively trying to do just that.
The potential application of tissue engineering for treating human hair loss is obvious and exciting. By analogy, cell therapy treatment for burns and ulcers consists of taking a postage size area of skin and growing it in the laboratory to create enough cells to cover an entire football field. These cells can then be used to treat several patients. If the cells of the hair follicle could be multiplied in the laboratory and placed back into the balding scalp, it may be possible to create thousands of hair follicles from that original follicle. In fact, this phenomenon has already been proven feasible in humans. However, this research is currently still in the most preliminary of stages and there are indeed many obstacles to making this treatment safe and effective.
One important obstacle is ensuring that the implanted cells produce hair that has the same cosmetic characteristics of the original hair. Just as in hair transplantation procedures performed today, one key feature would be hair growth direction. The difference between an acceptable hair transplant and a truly superb, undetectable transplant can be as simple as the latter having hair growing at the natural acute angle to the skin. Even one-haired micrografts may not look natural if they grow straight up at a right angle. If cell therapy were ever proven successful for producing hair growth, that would not be enough. It would have to produce natural looking hair.
The most important consideration for government regulators such as the Food and Drug Administration (FDA) will be ensuring the safety of cell therapy for hair loss. The chief worry with using laboratory grown cells is that they might cause tumors when placed back into the skin. So far cell therapy for other applications has not been known to be associated with tumor formation. Before granting approval, the FDA would require adequate proof that implanted hair follicle cells did not give rise to any tumors.
Although the potential for cell therapy to provide an answer to those suffering with hair loss is great, these obstacles will prove challenging to researchers. Although a research group may at any point unexpectedly report that they have achieved success in these areas, the more likely scenario is many more years of basic research before we know what role cell therapy will play in the treatment of hair loss.
“Hair Cloning” is the ultimate goal of every hair transplantation surgeon. And it has been proven that cultured dermal papilla cells with a few passages retain their hair producing activity in rats. However, after several passages, their hair incusing actvity is lost. We believe the analysis of gene expression profile differences between in vivo dermal papilla and cultured dermal papilla cells is the key step experiment for successful hair cloning in humans. Previously, we have established many cDNA libraries from cultured dermal papilla cells and conducted a small EST (expressed sequence tags) project by sequencing randomly selected cDNA clones. We also constructed cDNA chips consisted of those EST clones that can be most appropriately used for hair research.
In this study, the authors examined the gene expression profile differences between in vivo derma papilla and cultured derma papilla cells using our hair specific cDNA microarray (TrichoGene chip).
In a previous experiment, we had shown that the gene expression profile of cultured derma papilla cells is unique and pretty much different from cultured derma fibroblasts. Cultured dermal papilla cells have myofibroblast-like characteristics and predominantly controlled by transforming growth factors (TGFs) pathway. In this study, cultured dermal papilla cells overexpressed the genes related with myofibroblaast-like cell nature. The functions of the most overexpressed genes in in vivo derma papilla in the develpoment or cycling of hair are not well known. Several factors, such as supplement of the factors originated from out root sheath cells, may partly revert their gene expression profile to in vivo dermal papilla.
According to gene expression analysis, culcutred dermal papilla cells are more like myfibroblast-like cells and pretty much different from in vivo derma papilla. Finding the factors or chemicals that can revert the gene expression patterns of cultured dermal papilla cells to in vivo dermal papilla will be the next goal.