A BLOODY RICE
A BLOODY RICE
A group xv of researchers from Wuhan University, in China, has developed a transgenic variety of rice in order to face the worldwide market demand for human serum albumin (HSA).
SA is a soluble, globular, unglycosylated monomeric protein that functions primarily as a carrier protein for steroids, fatty acids and thyroid hormones and plays an important role in stabilizing extracellular fluid volume. The market demand for HSA is estimated at more than 500 tons per year worlwide since it is widely used clinically to treat serious burn injuries, hemorrhagic shock, hypoproteinemia, fetal erythroblastosis and ascites caused by cirrhosis of the liver.
Currently, commercial production of HSA is mainly based on collected human plasma, which is limited in supply. Because of this, the shortage of human plasma led to a rapid increase in price of HSA, which resulted in fake albumin appearing on the market. Furthermore, there is an increasing public health concern with plasma-derived HSA due to its potential risk for transmission of blood-derived infectious pathogens such as hepatitis and HIV. Thus, the development of a low-cost method for the production of recombinant HSA is essential as a safer and potentially unlimited alternative to plasma-derived HSA.
In order to settle this problem, several transgenic systems have been sucessfully developed, from E. coli to transgenic animals, but none of them has proven to be cost-effective at large scale. These researchers from Wuhan University have developed a transgenic variety of rice, Oryza sativa, which expresses HSA gene under a strong endosperm-specific promoter. HSA levels in seeds reached almost 11% of total soluble protein and analysis of recombinant HSA confirm that there is no difference between plasma-derived HSA and recombinant HSA. Furthermore, this system shows a productivity rate of 2,75 g/kg of rice, being much higher that the cost-effective threshold (0,1 g/kg).
The only point to be assessed in the future is the field-scale production of this transgenic rice, but there shouldn't be any problem meanwhile its production follows the current guidelines from regulatory authorities.