Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2023
Höfundar / Authors: Stamatia-Maria Rapti (1), Zarko Urosevic (1), Erna Magnúsdóttir (1)
Starfsvettvangur / Affiliations: 1. Department of Anatomy and Biomedical Science, School of Health Sciences, University of Iceland.
Kynnir / Presenter: Erna Magnusdottir
Waldenström Macroglobulinemia (WM) is an incurable B-cell lymphoma with notable heterogeneity as cell phenotype ranges from B-cell to plasma cells. Further, BLIMP1 is a well-established transcription factor crucial for the plasma cell differentiation program.
To investigate BLIMP1's role in WM, we use the RPCI-WM1 cell line, which has been engineered to knockdown (KD) the endogenous BLIMP1 with a doxycycline-induced microRNA. The KD cell line was further engineered to rescue and overexpress BLIMP1 with a lentivirally delivered exogenous expression of a Destabilization Domain EGFP-BLIMP1. The exogenous protein is continuously degraded unless in the presence of Shield-1 molecule, which protects the protein from degradation.
Our experiments show that induced KD of BLIMP1 leads to increased double-strand breaks, and on day 6 there all dead. To elucidate the impact of different BLIMP1 levels on cell cycle and cell death, we use EdU, a thymidine analog incorporated into newly synthesized DNA during replication. Our experiments show that 48hr induction of the BLIMP1 KD cell line, 62%±3.6 of the cells are in G1 and 20%±1.5 are apoptotic versus 54%±2.5 and 5.9%±0.1 respectively in control cells. In contrast, when we overexpress BLIMP1, 42.5%±5 of cells are in the S-phase versus 29%±2.6 in the control.
We aim to examine BLIMP1 levels across the cell cycle and validate our hypothesis that increased BLIMP1 expression enhances proliferation and cell survival in other WM cell lines.