We’re living in such an exiting time now. We can perform experiments even without manual bench-work, just using online databases. Data mining experiments, for example, allow us to compare gene expression profile of cancer stem cell (CSC) versus normal or non-tumorigenic counterparts.

I failed on one data mining experiment on microarray data sets from Michael Clarke’s group of CD44+/CD24-/lo several months ago. I compared non-tumorigenic cancer cells to tumorigenic cancer cells using GSEA (Gene Set Enrichment Analysis by Tamayo, PNAS, 2005). I got NO difference, nothing significant pops up. If I combine recent publication from Sean Morrison’s group, then it is so clear that CD44+/CD24-/lo cell population is only more “tumorigenic” than other populations in NOD/SCID mice, NOT in NOG mice. Most likely, the difference observed in NOD/SCID mice is from the ability of these cells to escape from host immunity surveillance, specifically, NK cells. I ask myself if there are really cancer stem cells?

Eric Lander and Robert Weinberg just published their latest findings on inhibitors of cancer stem cell - they can be selectively killed!!! Marvelous. They performed a proof-of-concept screen to identify agents that selectively kill CD44+/CD24-/lo breast cancer cells. A magic compound called Salinomylcin popped up out of several diverse commercial libraries containing around 16K compounds. If you think CD44+/CD24-/lo cell population represents for CSC, then congratulations, somebody finally found chemotherapeutic agent that can selectively kill CSC!!!

It may be way too early to setup different chemotherapy protocols which basically dump more toxins on already suffering organisms right now. More detailed and in-depth researches are in desperate need to fill in the gap between light-headed basic research and down-to-earth clinical application.

Should we still choose cancer research as career? Definitely yes. Cancer contributes 1/4 death for human being and ranks second on the list of cause of death. Encouraging results have already emerged from kinase inhibitors, such as Gleevec and PKC412, which can make some leukemias controllable. Novel therapies, such as miRNA, are on their way to application. We are ready to rock!