Trackable Intratumor Microdosing and Spatial Profiling Provide Early Insights into Activity of Investigational Agents in the Intact Tumor Microenvironment.

Purpose: Cancer drug development is currently limited by a paradigm of preclinical evaluation that does not adequately recapitulate the complexity of the intact human tumor microenvironment (TME). To overcome this, we combined trackable intratumor microdosing (CIVO) with spatial biology readouts to directly assess drug effects in patient tumors in situ.

Experimental Design: In a first-of-its-kind phase 0 clinical trial, we explored the effects of an investigational stage SUMOylation-activating enzyme (SAE) inhibitor, subasumstat (TAK-981) in 12 patients with head and neck carcinoma (HNC).

SMYD2 inhibition-mediated hypomethylation of Ku70 contributes to impaired nonhomologous end joining repair and antitumor immunity.

DNA damage repair (DDR) is a double-edged sword with different roles in cancer susceptibility and drug resistance. Recent studies suggest that DDR inhibitors affect immune surveillance. However, this phenomenon is poorly understood.

Cancer-associated fibroblasts employ NUFIP1-dependent autophagy to secrete nucleosides and support pancreatic tumor growth.

Cancer-associated fibroblasts (CAFs) are one of the most prominent and active components in the pancreatic tumor microenvironment. Our data show that CAFs are critical for survival from pancreatic ductal adenocarcinoma (PDAC) on glutamine deprivation. Specifically, we uncovered a role for nucleosides, which are secreted by CAFs through autophagy in a nuclear fragile X mental retardation-interacting protein 1 (NUFIP1)-dependent manner, increased glucose utilization and promoted growth of PDAC.

Mesenchymal Lineage Heterogeneity Underlies Nonredundant Functions of Pancreatic Cancer-Associated Fibroblasts.

Cancer-associated fibroblast (CAF) heterogeneity is increasingly appreciated, but the origins and functions of distinct CAF subtypes remain poorly understood. The abundant and transcriptionally diverse CAF population in pancreatic ductal adenocarcinoma (PDAC) is thought to arise from a common cell of origin, pancreatic stellate cells (PSC), with diversification resulting from cytokine and growth factor gradients within the tumor microenvironment. Here we analyzed the differentiation and function of PSCs during tumor progression .

Non-Invasive Monitoring of Stromal Biophysics with Targeted Depletion of Hyaluronan in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDA) is characterized by a pronounced fibroinflammatory stromal reaction consisting of inordinate levels of hyaluronan (HA), collagen, immune cells, and activated fibroblasts that work in concert to generate a robust physical barrier to the perfusion and diffusion of small molecule therapeutics. The targeted depletion of hyaluronan with a PEGylated recombinant human hyaluronidase (PEGPH20) lowers interstitial gel-fluid pressures and re-expands collapsed intratumoral vasculature, improving the delivery of concurrently administered agents. Here we report a non-invasive means of assessing biophysical responses to stromal intervention with quantitative multiparametric magnetic resonance imaging (MRI) at 14 Tesla (T).

A BODIPY-Based Donor/Donor-Acceptor System: Towards Highly Efficient Long-Wavelength-Excitable Near-IR Polymer Dots with Narrow and Strong Absorption Features.

Bright long-wavelength-excitable semiconducting polymer dots (LWE-Pdots) are highly desirable for in vivo imaging and multiplexed in vitro bioassays. LWE-Pdots have been obtained by incorporating a near-infrared (NIR) emitter into the backbone of a polymer host to develop a binary donor-acceptor (D-A) system. However, they usually suffer from severe concentration quenching and a trade-off between fluorescence quantum yield (Φ ) and absorption cross-section (σ).

Photostable Ratiometric Pdot Probe for in Vitro and in Vivo Imaging of Hypochlorous Acid.

Developing probes for the detection of reactive oxygen species (ROS), a hallmark of many pathophysiological process, is imperative to both understanding the precise roles of ROS in many life-threatening diseases and optimizing therapeutic interventions. We herein report an all-in-one fluorescent semiconducting polymer based far-red to near-infrared (NIR) Pdot nanoprobe for the ratiometric detection of hypochlorous acid (HOCl). The fabrication takes the advantage of flexible polymer design by incorporating target-sensitive and target-inert fluorophores into a single conjugated polymer to avoid leakage or differential photobleaching problems existed in other nanoprobes.

Integrin-mediated traction force enhances paxillin molecular associations and adhesion dynamics that increase the invasiveness of tumor cells into a three-dimensional extracellular matrix.

Metastasis requires tumor cells to navigate through a stiff stroma and squeeze through confined microenvironments. Whether tumors exploit unique biophysical properties to metastasize remains unclear. Data show that invading mammary tumor cells, when cultured in a stiffened three-dimensional extracellular matrix that recapitulates the primary tumor stroma, adopt a basal-like phenotype.

Visualizing mechanical modulation of nanoscale organization of cell-matrix adhesions.

The mechanical properties of the extracellular matrix influence cell signaling to regulate key cellular processes, including differentiation, apoptosis, and transformation. Understanding the molecular mechanisms underlying mechanotransduction is contingent upon our ability to visualize the effect of altered matrix properties on the nanoscale organization of proteins involved in this signalling. The development of super-resolution imaging techniques has afforded researchers unprecedented ability to probe the organization and localization of proteins within the cell.

Tension and Transformation in Pancreas Cancer: Can Phenotype Break Free from the Chrysalis of Genotype?

A recent study finds that impaired TGFβ signaling can initiate a positive feedback loop between increasing ECM stiffness and epithelial cell contractility in pancreas cancer. Even more surprising is the possibility that this phenotype can liberate the epithelium from dependence on the genetic events that transformed it.

Interstitial Pressure in Pancreatic Ductal Adenocarcinoma Is Dominated by a Gel-Fluid Phase.

Elevated interstitial fluid pressure can present a substantial barrier to drug delivery in solid tumors. This is particularly true of pancreatic ductal adenocarcinoma, a highly lethal disease characterized by a robust fibroinflammatory response, widespread vascular collapse, and hypoperfusion that together serve as primary mechanisms of treatment resistance. Free-fluid pressures, however, are relatively low in pancreatic ductal adenocarcinoma and cannot account for the vascular collapse.

Optical painting and fluorescence activated sorting of single adherent cells labelled with photoswitchable Pdots.

The efficient selection and isolation of individual cells of interest from a mixed population is desired in many biomedical and clinical applications. Here we show the concept of using photoswitchable semiconducting polymer dots (Pdots) as an optical 'painting' tool, which enables the selection of certain adherent cells based on their fluorescence, and their spatial and morphological features, under a microscope. We first develop a Pdot that can switch between the bright (ON) and dark (OFF) states reversibly with a 150-fold contrast ratio on irradiation with ultraviolet or red light.

Mounting Pressure in the Microenvironment: Fluids, Solids, and Cells in Pancreatic Ductal Adenocarcinoma.

The microenvironment influences the pathogenesis of solid tumors and plays an outsized role in some. Our understanding of the stromal response to cancers, particularly pancreatic ductal adenocarcinoma, has evolved from that of host defense to tumor offense. We know that most, although not all, of the factors and processes in the microenvironment support tumor epithelial cells.

Discrete spatial organization of TGFβ receptors couples receptor multimerization and signaling to cellular tension.

Cell surface receptors are central to the cell's ability to generate coordinated responses to the multitude of biochemical and physical cues in the microenvironment. However, the mechanisms by which receptors enable this concerted cellular response remain unclear. To investigate the effect of cellular tension on cell surface receptors, we combined novel high-resolution imaging and single particle tracking with established biochemical assays to examine TGFβ signaling.

Force engages vinculin and promotes tumor progression by enhancing PI3K activation of phosphatidylinositol (3,4,5)-triphosphate.

Extracellular matrix (ECM) stiffness induces focal adhesion assembly to drive malignant transformation and tumor metastasis. Nevertheless, how force alters focal adhesions to promote tumor progression remains unclear. Here, we explored the role of the focal adhesion protein vinculin, a force-activated mechanotransducer, in mammary epithelial tissue transformation and invasion.

The cancer glycocalyx mechanically primes integrin-mediated growth and survival.

Malignancy is associated with altered expression of glycans and glycoproteins that contribute to the cellular glycocalyx. We constructed a glycoprotein expression signature, which revealed that metastatic tumours upregulate expression of bulky glycoproteins. A computational model predicted that these glycoproteins would influence transmembrane receptor spatial organization and function.

YAP forces fibroblasts to feel the tension.

Cancer-associated fibroblasts (CAFs) may contribute to tissue tension and cancer progression by increasing extracellular matrix (ECM) deposition and remodelling. However, how CAFs become activated and their roles in tumour mechanics have remained unclear. YAP is now identified as a tension-stimulated CAF activator that promotes malignancy through a mechanically reinforced feed-forward loop.

Scanning angle interference microscopy reveals cell dynamics at the nanoscale.

Emerging questions in cell biology necessitate nanoscale imaging in live cells. Here we present scanning angle interference microscopy, which is capable of localizing fluorescent objects with nanoscale precision along the optical axis in motile cellular structures. We use this approach to resolve nanotopographical features of the cell membrane and cytoskeleton as well as the temporal evolution, three-dimensional architecture and nanoscale dynamics of focal adhesion complexes.

Balancing forces: architectural control of mechanotransduction.

All cells exist within the context of a three-dimensional microenvironment in which they are exposed to mechanical and physical cues. These cues can be disrupted through perturbations to mechanotransduction, from the nanoscale-level to the tissue-level, which compromises tensional homeostasis to promote pathologies such as cardiovascular disease and cancer. The mechanisms of such perturbations suggest that a complex interplay exists between the extracellular microenvironment and cellular function.

Bio-enabled synthesis of metamaterials.

Biological systems offer more than an inspiration for the spontaneous hierarchical organization of matter at length scales between 1 and 1000 nm. They also provide useful principles and molecular building blocks that have recently emerged with the proven ability to generate extended three-dimensional structures of hybrid biotic/abiotic components arranged with molecular precision. These principles and tools draw from the methods of molecular biology and modern biochemistry and are expected to provide unmatched flexibility in building supramolecular architectures, notably structures made of artificial atoms whose coupled responses to electromagnetic or elastic excitations have been predicted to yield astonishing properties unparalleled by any conventional materials.

Optical field enhancement at cusps between adjacent nanoapertures.

Optical nonlinear properties of cusps formed at the junction between two circular apertures in a metal film have been studied by scanning confocal microscopy. For gold, both second harmonic and broadband emission are enhanced when the pump polarization is directed across the gap between cusps, similar to the behavior of the recently studied bowtie antennas and apertures. However, field enhancements are also present when the polarization is perpendicular to the gap direction.