Programmed cell death (PCD) pathways, such as apoptosis, necroptosis and ferroptosis, play a critical role in organism development, tissue homeostasis and malignancy pathogenesis. Evasion of PCD is essential to sustain tumor growth and contributes to tumor resistance against therapies. Acute myeloid leukemia (AML) is a heterogeneous hematologic malignancy with unmet clinical needs. Therapies directly stimulating apoptosis have shown clinical promise in treating some subsets of patients with AML. However, resistance to such therapies is commonly observed in patients. Our research goals are thus to expand the knowledge domain of PCD and leverage it in treating AML and other hematological malignancies.
Identifying the novel genetic and chemical regulators of programmed cell death (PCD)
We are applying functional genomics approaches to identify the novel regulators of PCD for tackling cancer.
As elucidating PCD operation can advance anti-cancer strategies, one focus of our research will be the identification and in-depth mechanistic investigation of genes essential for restraining PCD activation in AML cells. We have applied parallel CRISPR screens to systematically uncover novel genetic regulators of PCD. While apoptosis has long been exploited as a defense mechanism against cancer, we will also focus on other PCD modes, such as necroptosis and ferroptosis, which have emerged as promising avenues to eliminate cancers resistant to apoptosis. A similar screen platform will be utilized to elucidate the cell death mechanisms of cytotoxic small molecule compounds with anti-leukemia potential, and to identify novel chemical inducers of PCD. Our research will improve our understanding of PCD regulation and provide guidance for designing more efficacious therapy combinations against difficult-to-treat cancers. Notably, our discovery efforts have revealed MARCH5, an ubiquitin E3 ligase localized on mitochondria, as an important apoptosis regulator and a promising therapeutic target for AML. We have shown that MARCH5 is required for maintaining the activity of MCL1, an important apoptosis defender in AML and many other cancers. Depletion of MARCH5 not only triggers AML cell death but also enhances the efficacy of other apoptosis-directed therapies. Our ongoing work will elucidate the mechanism of MARCH5 in regulating AML apoptosis and delineate the molecular machinery of MARCH5, which will offer opportunities for developing MARCH5-targeted therapies as an AML treatment.
Investigating the vulnerabilities of acute leukemia driven by onco-fusion proteins
We are utilizing integrated methods to dissect survival programs essential for acute leukemia driven by onco-fusion proteins.
Acute leukemia driven by an onco-fusion protein commonly develops a dependency on selective survival programs to cope with oncogenic stresses and sustain tumor growth. For instance, leukemia cells harboring MLL-fusion proteins depend on BCL2 to evade apoptosis, and those with AML1-ETO rely on MPL-BCLXL pathway to survive. The CBFA2T3-GLIS2 (CG) fusion protein drives a subset of pediatric AML that is highly refractory to current standard therapies and has an extremely poor outcome. Integrating multiple approaches, such as functional genomic screens, CRISPR-competent patient-derived xenografts (PDXs), and leukemogenesis modeling with health human CD34+ hematopoietic stem cells, we will work on dissecting the survival pathways underlying CG-driven AML.
We will evaluate the translational potential of candidate targets in preclinical studies using PDX models and immunodeficient mice. We will also investigate the functional impact of inhibiting those targets on human normal hematopoiesis. Our goal is to discover the effective and selective therapeutic opportunities against CG-driven AML.
- Lin S, Larrue C, Seong BKA, Dharia NV, Kuljanin M, Wechsler CS, Kugener G, Robichaud AL, Conway AS, Mashaka T, Mouche S, Adane B, Ryan JA, Mancias JD, Younger ST, Piccioni F, Lee LH, Wunderlich M, Letai A, Tamburini J, Stegmaier K. An in vivo CRISPR screening platform for prioritizing therapeutic targets in AML. Cancer Discovery. 2022; 12(2):432-449. PMCID: PMC8831447.
- Tarumoto Y*, Lin S*, Wang J, Milazzo JP, Xu Y, Lu B, Yang Z, Wei Y, Polyanskaya S, Wunderlich M, Gray NS, Stegmaier K, Vakoc CR. Salt-Inducible Kinase inhibition suppresses acute myeloid leukemia progression in vivo. Blood. 2020; 135(1):56-70. PMCID: PMC6940199.
- Lin S, Ptasinska A, Chen X, Shrestha M, Assi SA, Chin PS, Imperato MR, Aronow B, Zhang J, Weirauch MT, Bonifer C, Mulloy JC. A FOXO1-induced oncogenic network defines the AML1-ETO preleukemic program. Blood. 2017; 130(10):1213-1222. PMCID: PMC5606002.
- Lin S*, Luo RT*, Ptasinska A, Kerry J, Assi SA, Wunderlich M, Imamura T, Kaberlein JJ, Rayes A, Althoff MJ, Anastasi J, O'Brien MM, Meetei AR, Milne TA, Bonifer C, Mulloy JC, Thirman MJ. Instructive Role of MLL-Fusion Proteins Revealed by a Model of t(4;11) Pro-B Acute Lymphoblastic Leukemia. Cancer Cell. 2016; 30(5):737-749.
See a complete list of publications in Dr. Lin's NCBI bibliography.