GENE REGULATION IN CANCER

CANCER GENE REGULATION BY MICRO RNA

MicroRNAs  in cancer medicine is a hot field of endeavor today.  Genes are regulated by micro RNAs  (miRNA).   If the microRNA is poorly regulated, it can cause cancer and other diseases.  This advance is useful to make early diagnoses of disease and get new targets for antiviral drugs.

MicroRNA is a small noncoding RNA found in eukaryotes.  It has a unique compartment, is rapidly reversible and evolvable.  It is linked to cancer heart disease, diabetes, viral disease and a growing list of other ailments.  Human defects are caused by their deficiency.

Five hundred of the 25,000 human genes have microRNAs.  They are the regulators of the master regulator and control the entire pathway of genes.

Some diseases have too much micronRNA and their expression could be suppressed by injecting a complimentary RNA sequence to disable the target microRNA.

HEART  

The microRNA encodes the muscle protein myosin that helps the heart contract. Small bits of these nucleic acids can affect the adult heart.  Many myosin genes have microRNA that regulate one other to keep the heart healthy.  It may be possible to shoot extra microRNA or its suppressors directly into the heart.

CANCER

MicroRNAs in cancer cells behave differently than normal cells in the same organ.  Disease prognosis can correlate with the patterns of microRNAs expression.  If a microRNA is under expressed in a cancer, replenishing its microRNA supply stops the disease.  At least in Petri dishes.  Extra microRNAs don’t affect the normal cells.

A protein (myco) is found in very active caner cells and regulates dozens of microRNAs.  Some proteins made by oncogenes disable microRNAs, but in other cancers the microRNAs control the oncogenes.

Early cancer detection can be done by looking @ microRNA activity in metastatic tumors of unknown origin.  This occurs in 3% of cancers.  The type of cancer and origin was identified in 75% of the cases.  Traditional methods only were successful in 5% of the time.

DIABETES

Insulin producing beta cells express mir-375.  This miR 375 help the pancreas adapt to stresses when the body is called to produce extra insulin.

VIRAL INFECTIONS

How do viruses interact with natural RNA machinery?  Some viruses make microRNAs that give pathogens an advantage against the human.  Herpes virus makes tons of microRNA, especially Epstein Barr virus. 

Disabling some of the viral microRNA makes the virus less harmful.  Viruses seem to need the microRNA that they carry.  Work is now being done to blunt the microRNA in the human liver.

MOLECULAR BIOLOGY COMPANIES

 Biologists are rapidly forming new companies.  Companies like Asurogen, Cragen, and Rosetta Genomics are focusing on cancers. A company called Regular Therapeutic is focusing on heart and muscle disease.  The list goes on and on.

The hunt is on for new ways to diagnose and treat common diseases.   Biologists and their companies race to decipher the promise of these RNAs.  What are needed now are genetically engineered animals born without specific microRNAs. 

Science marches on.  What do you think?

         Source: Science: March 28,2008

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