Cass Nordmann - Dr. Sandra Demaria - Week 5

 This week was relatively slow. As Thursday was a holiday, most people in my lab didn’t work on Thursday or Friday. On Monday the Demaria lab welcomed a new postdoc, so that took a good portion of my day. The rest I spent reading literature for a small research project I began discussing with another postdoc on the previous Friday and planning for my Tuesday meetings. I spent most of my Tuesday attending various meetings; first I went to our program’s weekly meeting, then had to leave early to attend a lab meeting, then had a short break before I had a Zoom meeting with my lab back in Ithaca. During the lab meeting Diego, the medical student who I’ve been working closely with gave a progress report on his project and had some preliminary data from the flow cytometry that I shadowed. Unfortunately, of his three blood donors from which he extracted macrophages, only one had a substantial number of cells he could use to study how the immune cells responded to conditioned media from tumor organoids. Between the samples, there was a great deal of variability in the expression of key biomarkers. The blood donors he has used so far have been women in their 40s and 50s, the rationale being that breast cancer is more common in older, postmenopausal women, so the immune cells that he tests should be from this demographic to obtain the most clinically relevant results. However, the lab discussed whether the benefits of this clinical accuracy may be outweighed by the need to get samples that have higher cell counts and less cell phenotype variability.

I also briefly got to discuss the project that I hopefully will be working on for the next few weeks. Since I’ve been here, lab members have been having some trouble working with Matrigel and have been concerned about whether to use it or similar products for different organoid lines. Matrigel is a basement membrane extract, which means it is derived from the extracellular matrix that surrounds ducts and blood vessels. However, it’s properties and makeup are completely different from the majority of tissue in the breast and the rest of the body, which is mostly made of collagen I, the matrix protein that my lab in Ithaca uses. Nobody in the Demaria lab has tried to grow organoids in collagen I before so I plan to do so and compare their growth and behavior to organoids grown in Matrigel and other basement membrane extracts. I ordered some materials I’ll need this week, and, in the meantime, I’ve been doing literature review and planning how I’ll do my experiment.

On Wednesday I went to the histology core with the medical students and a lab technician from the department who works on establishing new organoids from patient samples. Diego was doing some histology on some of his organoids, so the tech was giving him some training on how to use the core facility. I was able to see how tissue samples are embedded in paraffin wax and saw the equipment for slicing the sample once it’s been fixed. We made plans with the staff at the core facility for the medical students and I to receive actual histology training next week, which I’m looking forward to.