I am a rising senior at Penn majoring in molecular and cellular biology with plans to apply to continue my education at the graduate level. I became interested in environmental toxicology during the course of my junior year research. I studied the outcomes of cigarette smoke on lung adenocarcinoma in Dr. David Feldser’s lab, which I continued as a STEER participant this summer.
Cigarette smoke is known to be a substantial risk factor for Kras-driven lung adenocarcinoma. Amplification of the Raf/Mek/Erk (MAPK) pathway has been shown to drive both initiation and progression in murine Kras-driven lung adenocarcinoma. As lung adenocarcinoma is frequently caused by insults to the lungs, we were interested in probing whether smoking-related lung adenocarcinoma is a MAPK amplification-mediated process. It has been previously demonstrated that immortalized human bronchial epithelial cells (HBECs) with expression of oncogenic KrasV12 and loss of p53 do not achieve complete malignant transformation (Sato et al 2006). We hypothesize the extent to which MAPK is driven in this model (by endogenous oncogenic Kras expression) is insufficient for transformation so we look to investigate the potential of cigarette smoke to drive MAPK signaling in HBECs and if that increase in signaling increases transformation.
To go about probing this, we set up a system where HBECs were seeded on transwell permeable inserts and exposed to the air/liquid interface (ALI) before being exposed to cigarette smoke. I tested the air/liquid interface (ALI) cell culture setup used throughout these experiments by forced air exposure and demonstrated viability by flow cytometry. I then exposed HBEC cells to whole smoke with a Vitrocell VC1 smoking machine. I assessed viability post smoke exposure by flow cytometry and compared viability to forced air and incubator controls. Going forward, I plan to assess MAPK signaling activity and the transformative ability of HBECs post smoke exposure.