Superparamagnetic iron oxide nanoparticle enhanced percutaneous microwave ablation: Ex-vivo characterization using magnetic resonance thermometry.

BACKGROUND: Percutaneous microwave ablation (pMWA) is a minimally invasive procedure that uses a microwave antenna placed at the tip of a needle to induce lethal tissue heating. It can treat cancer and other diseases with lower morbidity than conventional surgery, but one major limitation is the lack of control over the heating region around the ablation needle. Superparamagnetic iron oxide nanoparticles have the potential to enhance and control pMWA heating due to their ability to absorb microwave energy and their ease of local delivery. PURPOSE: The purpose of this study is to experimentally quantify the capabilities of FDA-approved superparamagnetic iron oxide Feraheme nanoparticles (FHNPs) to enhance and control pMWA heating. This study aims to determine the effectiveness of locally injected FHNPs in increasing the maximum temperature during pMWA and to investigate the ability of FHNPs to create a controlled ablation zone around the pMWA needle. METHODS: PMWA was performed using a clinical ablation system at 915 MHz in ex-vivo porcine liver tissues. Prior to ablation, 50 uL 5 mg/mL FHNP injections were made on one side of the pMWA needle via a 23-gauge needle. Local temperatures at the FHNP injection site were directly compared to equidistant control sites without FHNP. First, temperatures were compared using directly inserted thermocouples. Next, temperatures were measured non-invasively using magnetic resonance thermometry (MRT), which enabled comprehensive four-dimensional (volumetric and temporal) assessment of heating effects relative to nanoparticle distribution, which was quantified using dual-echo ultrashort echo time (UTE) subtraction MR imaging. Maximum heating within FHNP-exposed tissues versus control tissues were compared at multiple pMWA energy delivery settings. The ability to generate a controlled asymmetric ablation zone using multiple FHNP injections was also tested. Finally, intra-procedural MRT-derived heat maps were correlated with gold standard gross pathology using Dice similarity analysis. RESULTS: Maximum temperatures at the FHNP injection site were significantly higher than control (without FHNP) sites when measured using direct thermocouples (93.1 ± 6.0°C vs. 57.2 ± 8.1°C, p = 0.002) and using non-invasive MRT (115.6 ± 13.4°C vs. 49.0 ± 10.6°C, p = 0.02). Temperature difference between FHNP-exposed and control sites correlated with total energy deposition: 66.6 ± 17.6°C, 58.1 ± 8.5°C, and 20.8 ± 9.2°C at high (17.5 ± 2.2 kJ), medium (13.6 ± 1.8 kJ), and low (8.8 ± 1.1 kJ) energies, respectively (all pairwise p < 0.05). Each FHNP injection resulted in a nanoparticle distribution within 0.9 ± 0.2 cm radially of the injection site and a local lethal heating zone confined to within 1.1 ± 0.4 cm radially of the injection epicenter. Multiple injections enabled a controllable, asymmetric ablation zone to be generated around the ablation needle, with maximal ablation radius on the FHNP injection side of 1.6 ± 0.2 cm compared to 0.7 ± 0.2 cm on the non-FHNP side (p = 0.02). MRT intra-procedural predicted ablation zone correlated strongly with post procedure gold-standard gross pathology assessment (Dice similarity 0.9). CONCLUSIONS: Locally injected FHNPs significantly enhanced pMWA heating in liver tissues, and were able to control the ablation zone shape around a pMWA needle. MRI and MRT allowed volumetric real-time visualization of both FHNP distribution and FHNP-enhanced pMWA heating that was useful for intra-procedural monitoring. This work strongly supports further development of a FHNP-enhanced pMWA paradigm; as all individual components of this approach are approved for patient use, there is low barrier for clinical translation.

Intratumoral drug-releasing microdevices allow in situ high-throughput pharmaco phenotyping in patients with gliomas.

The lack of reliable predictive biomarkers to guide effective therapy is a major obstacle to the advancement of therapy for high-grade gliomas, particularly glioblastoma (GBM), one of the few cancers whose prognosis has not improved over the past several decades. With this pilot clinical trial (number NCT04135807), we provide first-in-human evidence that drug-releasing intratumoral microdevices (IMDs) can be safely and effectively used to obtain patient-specific, high-throughput molecular and histopathological drug response profiling. These data can complement other strategies to inform the selection of drugs based on their observed antitumor effect in situ. IMDs are integrated into surgical practice during tumor resection and remain in situ only for the duration of the otherwise standard operation (2 to 3 hours). None of the six enrolled patients experienced adverse events related to the IMD, and the exposed tissue was usable for downstream analysis for 11 out of 12 retrieved specimens. Analysis of the specimens provided preliminary evidence of the robustness of the readout, compatibility with a wide array of techniques for molecular tissue interrogation, and promising similarities with the available observed clinical-radiological responses to temozolomide. From an investigational aspect, the amount of information obtained with IMDs allows characterization of tissue effects of any drugs of interest, within the physiological context of the intact tumor, and without affecting the standard surgical workflow.

MYC Deregulation and PTEN Loss Model Tumor and Stromal Heterogeneity of Aggressive Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) patients have a poor prognosis and few treatment options. Mouse models of TNBC are important for development of new therapies, however, few mouse models represent the complexity of TNBC. Here, we develop a female TNBC murine model by mimicking two common TNBC mutations with high co-occurrence: amplification of the oncogene MYC and deletion of the tumor suppressor PTEN. This Myc;Ptenfl model develops heterogeneous triple-negative mammary tumors that display histological and molecular features commonly found in human TNBC. Our research involves deep molecular and spatial analyses on Myc;Ptenfl tumors including bulk and single-cell RNA-sequencing, and multiplex tissue-imaging. Through comparison with human TNBC, we demonstrate that this genetic mouse model develops mammary tumors with differential survival and therapeutic responses that closely resemble the inter- and intra-tumoral and microenvironmental heterogeneity of human TNBC, providing a pre-clinical tool for assessing the spectrum of patient TNBC biology and drug response.

Panobinostat Induced Spatial In Situ Biomarkers Predictive of Anti-PD-1 Efficacy in Mouse Mammary Carcinoma.

Immunotherapies, including anti-PD-1 immune checkpoint blocking (ICB) antibodies, have revolutionized the treatment of many solid malignancies. However, their efficacy in breast cancer has been limited to a subset of patients with triple-negative breast cancer, where ICBs are routinely combined with a range of cytotoxic and targeted agents. Reliable biomarkers predictive of the therapeutic response to ICB in breast cancer are critically missing, though a combination response has been associated with immunogenic cell death (ICD). Here, we utilized a recently developed integrated analytical platform, the multiplex implantable microdevice assay (MIMA), to evaluate the presence and spatial cell relations of literature-based candidate markers predictive of ICB efficacy in luminal mouse mammary carcinoma. MIMA integrates (i) an implantable microdevice for the localized delivery of small amounts of drugs inside the tumor bed with (ii) sequential multiplex immunohistochemistry (mIHC) and spatial cell analysis pipelines to rapidly (within days) describe drug mechanisms of action and find predictive biomarkers in complex tumor tissue. We show that the expression of cleaved caspase-3, ICAM-1, neuropilin-1, myeloperoxidase, calreticulin, galectin-3, and PD-L1 were spatially associated with the efficacy of panobinostat, a pan-HDAC inhibitor that was previously shown to induce immunogenic cell death and synergize with anti-PD-1 in breast cancer. PD-L1 by itself, however, was not a reliable predictor. Instead, ICB efficacy was robustly identified through the in situ hotspot detection of galectin-3-positive non-proliferating tumor zones enriched in cell death and infiltrated by anti-tumor cytotoxic neutrophils positive for ICAM-1 and neuropilin-1. Such hotspots can be specifically detected using distance-based cluster analyses. Single-cell measurements of the functional states in the tumor microenvironment suggest that both qualitative and quantitative effects might drive effective therapy responses. Overall, the presented study provides (i) complementary biological knowledge about the earliest cell events of induced anti-tumor immunity in breast cancer, including the emergence of resistant cancer stem cells, and (ii) newly identified biomarkers in form of specific spatial cell associations. The approach used standard cell-type-, IHC-, and FFPE-based techniques, and therefore the identified spatial clustering of in situ biomarkers can be readily integrated into existing clinical or research workflows, including in luminal breast cancer. Since early drug responses were detected, the biomarkers could be especially applicable to window-of-opportunity clinical trials to rapidly discriminate between responding and resistant patients, thus limiting unnecessary treatment-associated toxicities.

A multiplex implantable microdevice assay identifies synergistic combinations of cancer immunotherapies and conventional drugs.

Systematically identifying synergistic combinations of targeted agents and immunotherapies for cancer treatments remains difficult. In this study, we integrated high-throughput and high-content techniques-an implantable microdevice to administer multiple drugs into different sites in tumors at nanodoses and multiplexed imaging of tumor microenvironmental states-to investigate the tumor cell and immunological response signatures to different treatment regimens. Using a mouse model of breast cancer, we identified effective combinations from among numerous agents within days. In vivo studies in three immunocompetent mammary carcinoma models demonstrated that the predicted combinations synergistically increased therapeutic efficacy. We identified at least five promising treatment strategies, of which the panobinostat, venetoclax and anti-CD40 triple therapy was the most effective in inducing complete tumor remission across models. Successful drug combinations increased spatial association of cancer stem cells with dendritic cells during immunogenic cell death, suggesting this as an important mechanism of action in long-term breast cancer control.

A PDE Model of Breast Tumor Progression in MMTV-PyMT Mice.

The evolution of breast tumors greatly depends on the interaction network among different cell types, including immune cells and cancer cells in the tumor. This study takes advantage of newly collected rich spatio-temporal mouse data to develop a data-driven mathematical model of breast tumors that considers cells' location and key interactions in the tumor. The results show that cancer cells have a minor presence in the area with the most overall immune cells, and the number of activated immune cells in the tumor is depleted over time when there is no influx of immune cells. Interestingly, in the case of the influx of immune cells, the highest concentrations of both T cells and cancer cells are in the boundary of the tumor, as we use the Robin boundary condition to model the influx of immune cells. In other words, the influx of immune cells causes a dominant outward advection for cancer cells. We also investigate the effect of cells' diffusion and immune cells' influx rates in the dynamics of cells in the tumor micro-environment. Sensitivity analyses indicate that cancer cells and adipocytes' diffusion rates are the most sensitive parameters, followed by influx and diffusion rates of cytotoxic T cells, implying that targeting them is a possible treatment strategy for breast cancer.

Investigating key cell types and molecules dynamics in PyMT mice model of breast cancer through a mathematical model.

The most common kind of cancer among women is breast cancer. Understanding the tumor microenvironment and the interactions between individual cells and cytokines assists us in arriving at more effective treatments. Here, we develop a data-driven mathematical model to investigate the dynamics of key cell types and cytokines involved in breast cancer development. We use time-course gene expression profiles of a mouse model to estimate the relative abundance of cells and cytokines. We then employ a least-squares optimization method to evaluate the model's parameters based on the mice data. The resulting dynamics of the cells and cytokines obtained from the optimal set of parameters exhibit a decent agreement between the data and predictions. We perform a sensitivity analysis to identify the crucial parameters of the model and then perform a local bifurcation on them. The results reveal a strong connection between adipocytes, IL6, and the cancer population, suggesting them as potential targets for therapies.

A Mathematical Model of Breast Tumor Progression Based on Immune Infiltration.

Breast cancer is the most prominent type of cancer among women. Understanding the microenvironment of breast cancer and the interactions between cells and cytokines will lead to better treatment approaches for patients. In this study, we developed a data-driven mathematical model to investigate the dynamics of key cells and cytokines involved in breast cancer development. We used gene expression profiles of tumors to estimate the relative abundance of each immune cell and group patients based on their immune patterns. Dynamical results show the complex interplay between cells and molecules, and sensitivity analysis emphasizes the direct effects of macrophages and adipocytes on cancer cell growth. In addition, we observed the dual effect of IFN-γ on cancer proliferation, either through direct inhibition of cancer cells or by increasing the cytotoxicity of CD8+ T-cells.

Microenvironment-Mediated Mechanisms of Resistance to HER2 Inhibitors Differ between HER2+ Breast Cancer Subtypes.

Extrinsic signals are implicated in breast cancer resistance to HER2-targeted tyrosine kinase inhibitors (TKIs). To examine how microenvironmental signals influence resistance, we monitored TKI-treated breast cancer cell lines grown on microenvironment microarrays composed of printed extracellular matrix proteins supplemented with soluble proteins. We tested ∼2,500 combinations of 56 soluble and 46 matrix microenvironmental proteins on basal-like HER2+ (HER2E) or luminal-like HER2+ (L-HER2+) cells treated with the TKIs lapatinib or neratinib. In HER2E cells, hepatocyte growth factor, a ligand for MET, induced resistance that could be reversed with crizotinib, an inhibitor of MET. In L-HER2+ cells, neuregulin1-ß1 (NRG1ß), a ligand for HER3, induced resistance that could be reversed with pertuzumab, an inhibitor of HER2-HER3 heterodimerization. The subtype-specific responses were also observed in 3D cultures and murine xenografts. These results, along with bioinformatic pathway analysis and siRNA knockdown experiments, suggest different mechanisms of resistance specific to each HER2+ subtype: MET signaling for HER2E and HER2-HER3 heterodimerization for L-HER2+ cells.

Long-Term Engraftment of Primary Bone Marrow Stromal Cells Repairs Niche Damage and Improves Hematopoietic Stem Cell Transplantation.

Hematopoietic stem cell (HSC) transplantation represents a curative treatment for various hematological disorders. However, delayed reconstitution of innate and adaptive immunity often causes fatal complications. HSC maintenance and lineage differentiation are supported by stromal niches, and we now find that bone marrow stroma cells (BMSCs) are severely and permanently damaged by the pre-conditioning irradiation required for efficient HSC transplantation. Using mouse models, we show that stromal insufficiency limits the number of donor-derived HSCs and B lymphopoiesis. Intra-bone transplantation of primary, but not cultured, BMSCs quantitatively reconstitutes stroma function in vivo, which is mediated by a multipotent NT5E+ (CD73)+ ENG- (CD105)- LY6A+ (SCA1)+ BMSC subpopulation. BMSC co-transplantation doubles the number of functional, donor-derived HSCs and significantly reduces clinically relevant side effects associated with HSC transplantation including neutropenia and humoral immunodeficiency. These data demonstrate the potential of stroma recovery to improve HSC transplantation.

CAS directly interacts with vinculin to control mechanosensing and focal adhesion dynamics.

Focal adhesions are cellular structures through which both mechanical forces and regulatory signals are transmitted. Two focal adhesion-associated proteins, Crk-associated substrate (CAS) and vinculin, were both independently shown to be crucial for the ability of cells to transmit mechanical forces and to regulate cytoskeletal tension. Here, we identify a novel, direct binding interaction between CAS and vinculin. This interaction is mediated by the CAS SRC homology 3 domain and a proline-rich sequence in the hinge region of vinculin. We show that CAS localization in focal adhesions is partially dependent on vinculin, and that CAS-vinculin coupling is required for stretch-induced activation of CAS at the Y410 phosphorylation site. Moreover, CAS-vinculin binding significantly affects the dynamics of CAS and vinculin within focal adhesions as well as the size of focal adhesions. Finally, disruption of CAS binding to vinculin reduces cell stiffness and traction force generation. Taken together, these findings strongly implicate a crucial role of CAS-vinculin interaction in mechanosensing and focal adhesion dynamics.

SH3 domain tyrosine phosphorylation--sites, role and evolution.

BACKGROUND: SH3 domains are eukaryotic protein domains that participate in a plethora of cellular processes including signal transduction, proliferation, and cellular movement. Several studies indicate that tyrosine phosphorylation could play a significant role in the regulation of SH3 domains. RESULTS: To explore the incidence of the tyrosine phosphorylation within SH3 domains we queried the PhosphoSite Plus database of phosphorylation sites. Over 100 tyrosine phosphorylations occurring on 20 different SH3 domain positions were identified. The tyrosine corresponding to c-Src Tyr-90 was by far the most frequently identified SH3 domain phosphorylation site. A comparison of sequences around this tyrosine led to delineation of a preferred sequence motif ALYD(Y/F). This motif is present in about 15% of human SH3 domains and is structurally well conserved. We further observed that tyrosine phosphorylation is more abundant than serine or threonine phosphorylation within SH3 domains and other adaptor domains, such as SH2 or WW domains. Tyrosine phosphorylation could represent an important regulatory mechanism of adaptor domains. CONCLUSIONS: While tyrosine phosphorylation typically promotes signaling protein interactions via SH2 or PTB domains, its role in SH3 domains is the opposite - it blocks or prevents interactions. The regulatory function of tyrosine phosphorylation is most likely achieved by the phosphate moiety and its charge interfering with binding of polyproline helices of SH3 domain interacting partners.