Ann Marie Billig

Health Science, '18


miRNA analysis in mouse model of metastatic breast cancer. (Proj 2) The inhibition of PD-L1 on a Pan02 cell line w/ siRNA-nanodrug & gemcitabine treatment

Mentor: Zdravka Medarova, PhD (Martinos Center for Biomedical Imaging at Massachusetts General Hospital)

Project 1: In this project, three balb/c female mice were injected with a 4t1 cell line that promotes metastatic breast cancer. Mice were imaged every week starting three weeks post-injection using IVIS optical imaging. After about five weeks, the primary tumors were removed and their RNA was extracted. For the two weeks following primary tumor removal, the metastasis in these three mice were imaged and monitored. Upon sacrifice, metastasis was found in skull muscle, kidneys, periosteum, lungs, cardiac muscle, and lymph nodes. The RNA for these metastases were extracted using Qiagen's Rneasy Extraction Kit. Next, the RNA samples were sent to Exiqon for global microarray analysis to look for miRNA uniformly up regulated in the metastatic lesions relative to the primary tumors. MiR-645 and miR-1290 are expected to be commonly over expressed miRNAS. Project 2: For my second project, my lab focused on treating non-metastatic pancreatic cancer. We focused on the programmed dealth-ligand 1 (PD-L1). PD-L1 is a transmembrane protein that contributes to supressing the immune system by releasing a signal that inhibits the producting of CD-8+ T cells. Some studies have come to suspect that the upregulation of PD-L1 permits cancer to takeover the immune system.

For project 1: Metastases of mice with human breast cancer cell 4t1 were imaged using IVIS optical imaging three weeks post cell injection. Luciferase was used as reporter to visualize the tumors. Luciferase is a gene expressed in tumor cells that interacts with a luciferin substrate that is injected into the mice prior to imaging. This interaction produces the light that is picked up by IVIS. Region of Interest (ROI) values designates the borders of the tumors Source: