Cass Nordmann - Dr. Sandra Demaria - Week 2

 Week 2 was much more eventful for me as Dr. Demaria was able to come back to work. She’s very involved in her lab’s research, so I’ve already had a lot of opportunities to see how she approaches research questions. I find it interesting how clinicians will ask about factors that are not necessarily featured in an in vitro or in vivo model but would be considered in patient care. It seems to me like clinical researchers are a lot more concerned with remaining as faithful to human physiology as possible and less with creating models for individual specific phenomena like my own research is. This week, I was able to observe how Dr. Demaria’s lab splits their organoid cultures. I was surprised by how similar it was to my own experience with cell culture. Just like with cell lines, they use trypsin to dissociate the cells, then spin them down and aspirate the supernatant. The only difference is that their organoids are grown within Matrigel bubbles so the trypsin also needs to digest the matrix proteins before the cells can be split. Sometimes, after centrifuging the cell solution, a layer of Matrigel is still visible on top of the pellet and further trypsinization is required. Some mechanical breakup might also be needed to get rid of the matrix. After they prepare the new cell-matrix solution they pipette four drops of solution into a single well and put the plate in the incubator to polymerize.

I was able to attend several meetings or talks this week. I arrived late due to the weekly immersion meeting, but at Dr. Demaria’s lab meeting Maud, the lab’s postdoc, gave a presentation on some of her work involving a model of breast cancer wherein mice are injected with a mouse mammary adenocarcinoma cell line. She performed single-cell RNA sequencing to measure dendritic cell phenotypes when given radiotherapy, an antibody treatment, or a combination therapy. I was also able to attend work-in-progress talks at the Greenberg Cancer Center on a gene mutation that drives prostate cancer phenotype and a deep learning model created to predict cancer drug synergy for precision medicine. The Radiation Oncology departmental meeting on Wednesday was a journal talk. I attended a lecture given by pathology residents on Thursday on a protein electrophoresis technique that they use and another journal talk about a preclinical hemophilia treatment study. I found it interesting that the attending physician at this lecture spoke up and was quite dissatisfied with the model presented in the paper. He felt that they were excluding important proteins involved in blood clotting from their study and that they did not adequately challenge their model to test scenarios in which they would expect adverse outcomes. He referred to the mouse model as “crude.”

This week's highlight was finally getting to see the pathology lab on Tuesday, Thursday, and Friday. On Tuesday, Dr. Demaria took me to the pathology lab herself to introduce me to the clinicians there and allowed me to attend a consensus meeting. During these meetings, a group of pathologists sits around a table with microscope eyepieces at each seat, all connected to a single microscope. One of the pathologists will operate the microscope and present a case that they were having trouble with or wanted additional input on. The consensus meetings that I attended this week were only for breast pathology cases. During this first meeting, I got a chance to see how pathologists work and a fellow explained some of the stains they used to me such as H&E, keratin, ER, and HER2 stains. It was a bit overwhelming at the time, but afterward, Dr. Demaria gave me a pathology textbook to read and I think I’ve been able to start understanding a little of what’s going on. I attended another consensus meeting on Thursday and a smaller meeting with the resident I was shadowing and a couple others and began to recognize some spots that looked invasive, the ducts in the breast tissue, and fat. One of the residents I met on Tuesday, Carlos, was kind enough to allow me to shadow him while he processed breast samples in what they call “the gross room,” as this is where specimens undergo gross examination. Between Thursday and Friday, I was able to see one of every kind of case that a breast pathologist will routinely gross: a mastectomy with axillary lymph nodes, an unoriented lumpectomy, and an oriented lumpectomy with sentinel lymph nodes. I was able to feel some of the lymph nodes, breast tissue, and a large tumor, about 9cm long. Within the mastectomy specimen, I could also see areas that looked fibrous and were associated with tumors. It gave me a lot of valuable perspective for what real breast cancer should actually look and feel like which I can hopefully translate to my in vitro model research.