Molecular Engineering of Stimuli-Activatable Protein Degraders for Precise Cancer Therapy.

TARGETED PROTEIN DEGRADATION WITH PROTACS IN CANCER THERAPY: MECHANISMS, CLINICAL ADVANCES, CHALLENGES, AND FUTURE PERSPECTIVES

This thorough analysis investigates the molecular basis of PROTAC technology, tracking its progression from an elegant intellectual notion to a clinically approved treatment platform and provides a detailed survey of the current clinical landscape.

BioPROTACs: a promising approach for targeted protein degradation.

PROTAC-Based Strategies in Neurodegenerative Diseases: Challenges and Perspectives

This review summarizes recent advances in chemical protein degradation strategies for neurodegenerative disorders and highlights potential future perspectives of multifunctional PROTACs for therapeutic development.

Delivering Degradation: Nanomedicine and Programmable Proximity Platforms for Targeted Protein Degradation

Targeted protein degradation (TPD) represents a whole new paradigm in cell-level therapeutic design, with its ability to remove target proteins, normally through the endogenous proteasomal, lysosomal, or autophagic systems, rather than the traditional occupancy-driven inhibition approach. But the clinical efficacy of degraders is becoming more restricted based on delivery rather than efficacy only. Many proteolysis-targeting chimeras and new proximity-inducing systems have low solubility, are impermeable, are pharmacodynamically complicated, lack tissue selectivity, and cannot fully access the intracellular space. Nanomedicine and PD platforms could provide strategies not only to overcome these challenges, but also to provide other advantages, including enhancing exposure to degraders, biodistribution, controlled release, and context-dependent activation. This critical review is an outline of all lipid, polymeric, inorganic, biomimetic, targeted, activatable, and self-assembling delivery systems for TPD. We assess compositional considerations, in vitro and in vivo evidence, challenges for translation, and clinical endpoints required to support delivery-enabled degradation. Trusted TPD therapeutics need to relate different aspects of their design, such as degrader chemistry, carrier structure, disease biology, and pharmacodynamic biomarkers, to one another. Further investigations are needed to establish intact delivery of the degrader to the target, target depletion in relevant tissues, prolonged pharmacodynamics, favorable safety, and compelling therapeutic benefit relative to free degraders or traditional inhibitors. Thus, it is important to view delivery not simply as an additional step during formulation but as a design principle necessary for the reliable clinical outcome of degradation medicine.

Engineering Nonpathogenic Bacteria for Synergistic Tumor-Targeted Protein Degradation and Immunotherapy by Checkpoint-Inhibiting Nanobodies.

Microbial cell therapies hold considerable promise as programmable and versatile modalities for targeted interventions in complex biological environments. Here, we developed a living bacterial delivery platform that could leverage its endogenous metabolism to synchronize the release of surface-anchored targeted protein degradation (TPD) chimeras and the secretion of immune-modulatory nanobodies (Nbs) for enhanced antitumor efficacy. By means of metabolic labeling coupled with bioorthogonal click chemistry, transferrin (Tf)-CD24 antibody chimeras (TransCACs) were covalently displayed on the surface of nonpathogenic Escherichia coli (E. coli) K12. In parallel, this strain was equipped with a constitutive expression module for the in situ biosynthesis of PD-L1-blocking nanobodies. Capitalizing on the natural tumor tropism of bacteria, our engineered E. coli K12 achieved tumor-targeted CD24 degradation, thereby augmenting macrophage-mediated phagocytosis and synergizing with PD-L1 blockade to elicit robust tumor-specific CD8+ T cell immunity. In vivo administration of engineered microbes led to marked tumor growth inhibition in both subcutaneous breast and orthotopic hepatocellular carcinoma models, along with prolonged animal survival, driven by remodeling of the suppressive tumor microenvironment through coordinated crosstalk between M1-like macrophages and tumor-resident memory (TRM)-like CD8+ T cells. Altogether, this integrated genetic engineering and metabolic labeling of bacteria (InGeM) opens avenues for the development of next-generation microbe-based cancer immunotherapies.

In situ self-assembly of PROTACs for precision cancer therapy.

Proteolysis-targeting chimeras (PROTACs) are heterobifunctional molecules that degrade pathogenic proteins via the ubiquitin-proteasome system. Their event-driven mechanism enables targeting of traditionally undruggable proteins and overcomes acquired resistance through complete protein degradation. Despite these advantages in cancer therapy, clinical translation of PROTACs is hampered by high molecular weight, poor solubility, off-target effects, and the hook effect. To address these challenges, integrating bioorthogonal in situ self-assembly of PROTACs with advanced nanodelivery platforms has emerged as a promising strategy to enhance delivery efficiency, enable spatiotemporally controlled protein degradation, and reduce toxicity. This review systematically outlines design and construction strategies for in situ self-assembling PROTACs, highlighting recent advances in nanodelivery systems that improve solubility, bioavailability, and degradation efficacy while mitigating off-target effects and the hook effect. Finally, we discuss current challenges and future perspectives for PROTACs-based precision cancer therapy.