Transient, multi-protein complexes are important facilitators of cellular functions. This includes the chaperome, an abundant protein family comprising chaperones, co-chaperones, adaptors, and folding enzymes—dynamic complexes of which regulate cellular homeostasis together with the protein degradation machinery1–6. Numerous studies have addressed the role of chaperome members in isolation, yet little is known about their relationships regarding how they interact and function together in malignancy7–17. As function is probably highly dependent on endogenous conditions found in native tumours, chaperomes have resisted investigation, mainly due to the limitations of methods needed to disrupt or engineer the cellular environment to facilitate analysis. Such limitations have led to a bottleneck in our understanding of chaperome-related disease biology and in the development of chaperome-targeted cancer treatment. Here we examined the chaperome complexes in a large set of tumour specimens. The methods used maintained the endogenous native state of tumours and we exploited this to investigate the molecular characteristics and composition of the chaperome in cancer, the molecular factors that drive chaperome networks to crosstalk in tumours, the distinguishing factors of the chaperome in tumours sensitive to pharmacologic inhibition, and the characteristics of tumours that may benefit from chaperome therapy. We find that under conditions of stress, such as malignant transformation fuelled by MYC, the chaperome becomes biochemically ‘rewired’ to form a network of stable, survival-facilitating, high-molecular-weight complexes. The chaperones heat shock protein 90 (HSP90) and heat shock cognate protein 70 (HSC70) are nucleating sites for these physically and functionally integrated complexes. The results indicate that these tightly integrated chaperome units, here termed the epichaperome, can function as a network to enhance cellular survival, irrespective of tissue of origin or genetic background. The epichaperome, present in over half of all cancers tested, has implications for diagnostics and also provides potential vulnerability as a target for drug intervention.

The genetic transfer of antigen receptors provides a means to rapidly generate autologous tumor-reactive T lymphocytes. However, recognition of tumor antigens by cytotoxic T cells is only one step towards effective cancer immunotherapy. Other crucial biological prerequisites must be fulfilled to expand tumor-reactive T cells that retain a functional phenotype, including in vivo cytolytic activity and the ability to travel to tumor sites without prematurely succumbing to apoptosis. We show that these requirements are met by expanding peripheral blood T cells genetically targeted to the CD19 antigen in the presence of CD80 and interleukin-15 (IL-15). T cells expanded in the presence of IL-15 uniquely persist in tumor-bearing severe combined immunodeficiency (SCID)-Beige mice and eradicate disseminated intramedullary tumors. Their anti-tumor activity is further enhanced by in vivo co-stimulation. In addition, transduced T cells from patients with chronic lymphocytic leukemia (CLL) effectively lyse autologous tumor cells. These findings strongly support the clinical feasibility of this therapeutic strategy.

89 78.41 h) is a positron-emitting radionuclide that displays excellent potential for use in the design and synthesis of radioimmunoconjugates for immunoPET. In the current study, we report the preparation of 89 Zr-desferrioxamine B (DFO)-J591, a novel 89 Zr-labeled monoclonal antibody (mAb) construct for targeted immunoPET and quantification of prostate-specific membrane antigen (PSMA) expression in vivo. Methods: The in vivo behavior of 89 Zr-chloride, 89 Zr-oxalate, and 89 Zr-DFO was studied using PET. High-level computational studies using density functional theory calculations have been used to investigate the electronic structure of 89 Zr-DFO and probe the nature of the complex in aqueous conditions. 89 Zr-DFO-J591 was characterized both in vitro and in vivo. ImmunoPET in male athymic nu/nu mice bearing subcutaneous LNCaP (PSMA-positive) or PC-3 (PSMA-negative) tumors was conducted. The change in 89 Zr-DFO-J591 tissue uptake in response to high-and low-specific-activity formulations in the 2 tumor models was measured using acute biodistribution studies and immunoPET. Results: The basic characterization of 3 important reagents-89 Zr-chloride, 89 Zr-oxalate, and the complex 89 Zr-DFO-demonstrated that the nature of the 89 Zr species dramatically affects the biodistribution and pharmacokinetics. Density functional theory calculations provide a rationale for the observed high in vivo stability of 89 Zr-DFO-labeled mAbs and suggest that in aqueous conditions, 89 Zr-DFO forms a thermodynamically stable, 8-coordinate complex by coordination of 2 water molecules. 89 Zr-DFO-J591 was produced in high radiochemical yield (.77%) and purity (.99%), with a specific activity of 181.7 6 1.1 MBq/mg (4.91 6 0.03 mCi/mg). In vitro assays demonstrated that 89 Zr-DFO-J591 had an initial immunoreactive fraction of 0.95 6 0.03 and remained active for up to 7 d. In vivo biodistribution experiments revealed high, target-specific uptake of 89 Zr-DFO-J591 in LNCaP tumors after 24, 48, 96, and 144 h (34.4 6 3.2 percentage injected dose per gram [%ID/g], 38.0 6 6.2 %ID/g, 40.4 6 4.8 %ID/g, and 45.8 6 3.2 %ID/g, respectively). ImmunoPET studies also showed that 89 Zr-DFO-J591 provides excellent image contrast, with tumorto-muscle ratios greater than 20, for the delineation of LNCaP xenografts between 48 and 144 h after administration. Conclusion: These studies demonstrate that 89 Zr-DFO-labeled mAbs show exceptional promise as radiotracers for immunoPET of human cancers. 89 Zr-DFO-J591 displays high tumor-to-background tissue contrast in immunoPET and can be used to delineate and quantify PSMA-positive prostate tumors in vivo.

Nanoparticle-based materials, such as drug delivery vehicles and diagnostic probes, currently under evaluation in oncology clinical trials are largely not tumor selective. To be clinically successful, the next generation of nanoparticle agents should be tumor selective, nontoxic, and exhibit favorable targeting and clearance profiles. Developing probes meeting these criteria is challenging, requiring comprehensive in vivo evaluations. Here, we describe our full characterization of an approximately 7-nm diameter multimodal silica nanoparticle, exhibiting what we believe to be a unique combination of structural, optical, and biological properties. This ultrasmall cancer-selective silica particle was recently approved for a first-in-human clinical trial. Optimized for efficient renal clearance, it concurrently achieved specific tumor targeting. Dye-encapsulating particles, surface functionalized with cyclic arginine-glycine-aspartic acid peptide ligands and radioiodine, exhibited high-affinity/avidity binding, favorable tumor-to-blood residence time ratios, and enhanced tumor-selective accumulation in α v β 3 integrin-expressing melanoma xenografts in mice. Further, the sensitive, real-time detection and imaging of lymphatic drainage patterns, particle clearance rates, nodal metastases, and differential tumor burden in a large-animal model of melanoma highlighted the distinct potential advantage of this multimodal platform for staging metastatic disease in the clinical setting.

No abstract