Computationally designed high specificity inhibitors delineate the roles of BCL2 family proteins in cancer
Abstract
Many cancers overexpress one or more of the six human pro-survival BCL2 family proteins to evade apoptosis. To determine which BCL2 protein or proteins block apoptosis in different cancers, we computationally designed three-helix bundle protein inhibitors specific for each BCL2 pro-survival protein. Following in vitro optimization, each inhibitor binds its target with high picomolar to low nanomolar affinity and at least 300-fold specificity. Expression of the designed inhibitors in human cancer cell lines revealed unique dependencies on BCL2 proteins for survival which could not be inferred from other BCL2 profiling methods. Our results show that designed inhibitors can be generated for each member of a closely-knit protein family to probe the importance of specific protein-protein interactions in complex biological processes.
Data availability
-
Computationally designed, high specificity inhibitors delineate the roles of BCL2 family proteins in cancerPublicly available at the NCBI Gene Expression Omnibus (accession no: GSE80194).
Article and author information
Author details
Funding
National Institutes of Health (P41GM103533)
- Stephanie Berger
- Erik Procko
- David Baker
Australian Research Council (FT150100212)
- Erinna F Lee
National Institutes of Health (R01 GM115545)
- Betty W Shen
- Barry L Stoddard
National Institutes of Health (R01 CA158921-04)
- Daciana Margineantu
- David M Hockenbery
Defense Threat Reduction Agency (HDTRA1-10-0040)
- Stephanie Berger
- Erik Procko
- David Baker
Howard Hughes Medical Institute (HHMI-027779)
- Stephanie Berger
- Erik Procko
- David Baker
National Science Foundation (Graduate Research Fellowship Program)
- Stephanie Berger
Worldwide Cancer Research (15-0025)
- Erinna F Lee
- W Douglas Fairlie
Cancer Council Victoria (1057949)
- Erinna F Lee
- W Douglas Fairlie
Pew Charitable Trusts
- Daniel-Adriano Silva
Consejo Nacional de Ciencia y Tecnología
- Daniel-Adriano Silva
National Health and Medical Research Council (1024620)
- Erinna F Lee
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2016, Berger et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 5,440
- views
-
- 1,126
- downloads
-
- 72
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Further reading
-
- Cancer Biology
Most human pancreatic ductal adenocarcinoma (PDAC) are not infiltrated with cytotoxic T cells and are highly resistant to immunotherapy. Over 90% of PDAC have oncogenic KRAS mutations, and phosphoinositide 3-kinases (PI3Ks) are direct effectors of KRAS. Our previous study demonstrated that ablation of Pik3ca in KPC (KrasG12D; Trp53R172H; Pdx1-Cre) pancreatic cancer cells induced host T cells to infiltrate and completely eliminate the tumors in a syngeneic orthotopic implantation mouse model. Now, we show that implantation of Pik3ca−/− KPC (named αKO) cancer cells induces clonal enrichment of cytotoxic T cells infiltrating the pancreatic tumors. To identify potential molecules that can regulate the activity of these anti-tumor T cells, we conducted an in vivo genome-wide gene-deletion screen using αKO cells implanted in the mouse pancreas. The result shows that deletion of propionyl-CoA carboxylase subunit B gene (Pccb) in αKO cells (named p-αKO) leads to immune evasion, tumor progression, and death of host mice. Surprisingly, p-αKO tumors are still infiltrated with clonally enriched CD8+ T cells but they are inactive against tumor cells. However, blockade of PD-L1/PD1 interaction reactivated these clonally enriched T cells infiltrating p-αKO tumors, leading to slower tumor progression and improve survival of host mice. These results indicate that Pccb can modulate the activity of cytotoxic T cells infiltrating some pancreatic cancers and this understanding may lead to improvement in immunotherapy for this difficult-to-treat cancer.
-
- Cancer Biology
- Immunology and Inflammation
In this study, we present a proof-of-concept classical vaccination experiment that validates the in silico identification of tumor neoantigens (TNAs) using a machine learning-based platform called NAP-CNB. Unlike other TNA predictors, NAP-CNB leverages RNA-seq data to consider the relative expression of neoantigens in tumors. Our experiments show the efficacy of NAP-CNB. Predicted TNAs elicited potent antitumor responses in mice following classical vaccination protocols. Notably, optimal antitumor activity was observed when targeting the antigen with higher expression in the tumor, which was not the most immunogenic. Additionally, the vaccination combining different neoantigens resulted in vastly improved responses compared to each one individually, showing the worth of multiantigen-based approaches. These findings validate NAP-CNB as an innovative TNA identification platform and make a substantial contribution to advancing the next generation of personalized immunotherapies.