RNAi: The Dream Makes a Comeback

This Promega Notes Cover from 2004 celebrated the potential stop and go power of DNA-directed RNAi.
This Promega Notes Cover from 2004 celebrated the potential stop and go power of DNA-directed RNAi.

In the early 2000s, RNAi was a hot topic. The science world was abuzz with all the possibilities that harnessing this natural process could hold. And why not? The idea of posttranscriptionally silencing genes using only a small fragment of double-stranded RNA is huge—big enough to earn the scientists who discovered it a Nobel Prize in 2006.

The process of RNAi starts with short (~70 nucleotieds), double-stranded fragments of RNA called short hairpin RNAs (shRNA). These shRNAs are exported into the cytoplasm and cleaved by the enzyme Dicer into smaller pieces of RNA that are about 21 nucleotides long and are referred to as small interfering RNAs (siRNA). The siRNAs reduce or stop expression of proteins through a sequence of events where the antisense strand of the siRNA is incorporated into and RNA-induced silencing complex (RISC), which then attaches to and degrades its complimentary messenger RNA, thereby reducing or completely stopping expression.

It turned out, however, that harnessing the promise of RNAi was a little trickier than anticipated. Continue reading “RNAi: The Dream Makes a Comeback”

Could the Next Chemotherapy be Derived from a Weed?

As much as I may complain about weeds, one that I enjoy (in moderation and not among my vegetables) is dandelions. The bright yellow flowers herald spring, and the seed puffballs, while not as visually interesting, offer entertainment as I watch birds landing on the shaft, bending it and eating the seeds. When I am pulling out the taproots with my dandelion weeding tool, I like to leave them on my lawn to break down because the roots are known to draw up nutrients. As it turns out, dandelion root is more than a nutrient source for other plants; it has been used for medicinal purposes. And now Ovadje, Hamm and Pandey have published research showing that dandelion root extract is able to induce apoptosis of leukemia cell lines while leaving normal blood cells untouched. Continue reading “Could the Next Chemotherapy be Derived from a Weed?”