Molecular Biology Program
The John Maciejowski Lab
Research
Associate Member
Cancer genomes are unstable. Chromosomes are mis-segregated, telomeres fail, and broken chromosomes fuse and break again. Each of these leaves DNA in the wrong place or the wrong state inside the cell, and the Maciejowski lab studies what follows.
One line of work concerns the immune consequences. DNA that escapes into the cytoplasm, at micronuclei and at chromosome bridges, is detected by the sensor cGAS and triggers an inflammatory response. The lab has shown that the exonuclease TREX1 degrades this DNA from the endoplasmic reticulum, that a protein barrier assembled around the exposed DNA governs access to it, and that tumors induce TREX1 to shield themselves from immune surveillance. Removing TREX1 restores antitumor immunity in tumors able to respond.
A second line concerns what instability writes into the genome. The lab studies APOBEC3A, a major source of point mutations in human cancer, and the rare, transient cell state that licenses its activity. It also studies extrachromosomal DNA, the circular elements that carry amplified oncogenes and are inherited through an active mechanism despite lacking centromeres.
The lab combines cell biology, biochemistry, and genomics. Full details of current research, people, publications, and openings are at maciejowskilab.org.
Research Projects
Featured News
People
John Maciejowski, PhD
Associate Member
- John Maciejowski studies how genomic instability shapes cancer. His lab works on how tumors keep the immune system from detecting their own displaced DNA, and on the patterns of mutation and oncogene amplification that instability writes into the cancer genome.
- PhD, Louis V. Gerstner, Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center
- [email protected]
- Email Address
Members
Achievements
- Cancer Immunology Research Award for Outstanding Journal Article (2026)
- Louise and Allston Boyer Young Investigator Award for Basic Research (2025)
- Pershing Square Sohn Cancer Research Alliance Prize (2023)
- Frank A. Howard Scholar (2022)
- Pew Biomedical Scholar (2019)
- V Foundation Scholar (2018)
- NIH Pathway to Independence Award (2016)
- Regeneron Prize for Creative Innovation (2016)
- Tri-Institutional Breakout Prize for Junior Investigators (2016)
