For the Greater Good

Yesterday, Wei (the Chinese MD who works in our lab) and I "sacrificed" two mice for the purpose of extracting dendritic cells from their bone marrow. We accomplished this by sticking each mouse into a shoebox sized gas chamber (one at a time, to ensure maximum freshness) and once expired (after about one minute), dissecting away the skin and muscles of both legs. Once the soft tissue was out of the way, it was a relatively simple matter to remove all of the leg bones (femur + tibia). The whole thing sounds a lot cleaner than it actually was. The end result was 7-8 tiny bones floating around in a petri dish. We took these bones under the hood and watched the color of the bones change to pearly-white as we flushed the marrow out using a small syringe and 25 gauge needle, with a buffer solution.

Today, Wei and I anesthetized six mice for the purpose of inoculating their livers with malignant tumor cells. We accomplished this by injecting anesthetic directly into the peritoneal cavity and once unconscious, performing surgery on the mice. Wei made a horizontal incision in the upper epigastrium with a pair of scissors, both at the surface level and into the peritoneum. He would then pull a large chunk of the liver (possibly all of it) out through the incision and rest it on the mouse's abdomen while he injected it with tumor cells cultured in the lab. Once hemostasis was achieved, he placed the liver back into the abdominal cavity and then passed it to me. I closed each incision by running a suture through both layers and tying off with three knots at each end.

Sewing up these tiny incisions was the highlight of my week. My suturing skills were quite rusty, but luckily, Wei had every bit of confidence in me. As I finished stitching that first mouse we operated on, I asked Wei, "OK, I think I'm done... how's it look?" He's a man of few words: "Still alive?" We both stared at the mouse intently for about two seconds. I breathed a sigh of relief. "Still alive!" He nodded, and continued working on the next mouse.

To summarize, yesterday, we gassed two mice and ripped out all of their leg bones. Today, we gave six mice liver cancer. And eventually, in three to six weeks, we will be killing these same six mice to collect data on how much the tumor has grown, how the normal liver tissue has responded to the tumor, and how all sorts of miscellaneous parameters relate to the immune response mounted by the mouse. The autologous dendritic cells I mentioned in the first paragraph are actually being used as a novel technology to vaccinate these mice who now have cancer. The idea is that this kind of immunotherapy will strengthen the host's natural response to the tumor and the results have actually been somewhat promising so far, at least in this simple murine model. Trials of a similar nature are currently being conducted in humans, and one of our goals as a research group is to eventually develop our own clinical trial.

That's the big picture. We call the deaths of many mice "sacrifices" for good reason, and it is because they are dying to further research that may someday help discover new technologies and treatments for cancer. While a small part of me cringes at the thought of what kind of activities I've been complicit in for these last two days, my conscience is assuaged by the fact that mice aren't nearly aware enough to appreciate that they are, in fact, being subject to great difficulties. And so I will continue to sacrifice my mice and give them cancer.

For the greater good.