The prosurvival Bcl-2 proteins exhibit a specific pattern of interactions with BH3-only proteins that determines the cellular dependence on apoptotic stress. This specificity is crucial for the development of BH3 mimetics, a class of anticancer molecules based on the BH3 domain with promising activity in clinical trials. Although complex formation mainly takes place in the mitochondrial outer membrane, most studies so far addressed the interaction between BH3 peptides and truncated Bcl-2 proteins in solution. As a consequence, quantitative understanding of the sequence specificity determinants of BH3 peptides in the membrane environment is missing. Here, we tackle this issue by systematically quantifying the ability of BH3 peptides to compete for the complexes between cBid and Bcl-xL in giant unilamellar vesicles and compare it with solution and mitochondria. We show that the BH3 peptides derived from Hrk, Bim, Bid, and Bad are the most efficient in disrupting cBid/Bcl-xL complexes in the membrane, which correlates with their activity in mitochondria. Our findings support the targeting to the membrane of small molecules that bind Bcl-2 proteins as a strategy to improve their efficiency.
BH3 mimetics are small‑molecule inhibitors of the antiapoptotic Bcl‑2 family and have therapeutic efficacy against hematological malignancies. BH3 mimetic A‑1331852 suppresses colorectal cancer cell proliferation. Progressive resistance to the widely used anticancer agent fluorouracil (5‑FU) is a key reason for colorectal cancer recurrence; therefore, the present study tested if A‑1331852 can suppress the proliferation of 5‑FU‑resistant colorectal cancer cells.
Apoptosis-regulating proteins from the B-cell lymphoma-2 (BCL-2) family are of continued interest as they represent promising targets for anti-cancer therapies. Myeloid cell leukemia-1 (MCL-1), which usually refers to the long isoform (MCL-1L) is frequently overexpressed in various types of cancer. However, MCL1 pre-mRNA can also undergo alternative splicing through exon skipping to yield the short isoform, MCL-1S.
T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy with poor response to conventional therapy, derived from hematopoietic progenitors committed to T-cell lineage. Relapsed/Refractory patients account for nearly 20% of childhood and 45% of adult cases. Aberrant Notch signaling plays a critical role in T-ALL pathogenesis and therapy resistance.
Acute myeloid leukemia (AML) is a complex clonal disorder characterized by clinical, genetic, metabolomic, and epigenetic heterogeneity resulting in the uncontrolled proliferation of aberrant blood-forming precursor cells. Despite advancements in the understanding of the genetic, metabolic, and epigenetic landscape of AML, it remains a significant therapeutic challenge. Functional profiling techniques, such as BH3 profiling (BP), gene expression profiling (GEP), proteomics, metabolomics, drug sensitivity/resistance testing (DSRT), CRISPR/Cas9, and RNAi screens offer valuable insights into the functional behavior of leukemia cells.
School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China.
Intracellular delivery of biologicals such as peptides, proteins, and nucleic acids presents a great opportunity for innovative therapeutics. However, the endosome entrapment remains a major bottleneck in the intracellular delivery of biomacromolecules, largely limiting their therapeutic potential. Here, we converted a cell-penetrating peptide (CPP), low molecular weight protamine (LMWP), to endosomal escape peptides (EEPs) by masking LMWP with a pH-responsive counter-ionic peptide.
