Multiparametric optical and MR imaging demonstrate inhibition of tumor angiogenesis natural history by mural cell therapy.

PURPOSE: To determine whether functional imaging using MRI and fibered confocal fluorescence microscopy (FCFM) could be used to monitor cell therapy by mural progenitor cells (MPC). METHODS: Fifty mice bearing TC1 murine xenograft tumors were allocated into: control (n = 17), sham (phosphate buffer saline, n = 16), and MPC-treated (MPC, n = 17) groups. MRI was performed before (D0 ) and 7 days (D7 ) after injection measuring tumor size, R2 * under air, oxygen, and carbogen using blood oxygen level dependent (BOLD) and f (fraction linked to microcirculation), D* (perfusion related coefficient) and Dr (restricted diffusion coefficient) using diffusion-weighted sequences based on the IVIM (intravoxel incoherent motion) method. FCFM was performed at D7 measuring "index leakage" (capillary permeability). RESULTS: Tumor growth was significantly slowed down in the MPC-treated animals (P = 0.002) on D7 . R2 *air significantly decreased in controls between D0 and D7 (P = 0.03), reflecting a decrease in tumor oxygenation. ΔR2 *O2CO2 significantly increased in controls between D0 and D7 (P = 0.01) reflecting loss of vessel response to carbogen. D* significantly decreased in controls between D0 and D7 (P = 0.03). Finally, "index leakage" was lower in the MPC-treated tumors (P = 0,009). CONCLUSION: Treatment by MPC resulted in slowing down of tumor growth, capillary permeability decrease, and stabilization of tumor angiogenesis.

Dynamic contrast enhanced-MRI in rectal cancer: Inter- and intraobserver reproducibility and the effect of slice selection on pharmacokinetic analysis.

PURPOSE: To assess inter- and intraobserver reproducibility of DCE-MRI measurements and possible differences between two directly adjacent slices. MATERIALS AND METHODS: DCE-MRI measurements of 30 patients with histologically proven rectal carcinoma were performed on a 1.5 Tesla (T) MR system during intravenous contrast agent application before and after neoadjuvant radiochemotherapy with two directly adjacent slices used for calculation per patient. Images were analyzed semiquantitatively (parameters TTP and MITR) and quantitatively using the Brix compartment model (parameters kep and A) by two different observers and at two different time points. The concordance correlation coefficient was calculated for every parameter in intra-/interobserver comparison and slice comparison. RESULTS: Median relative differences below 10% for all parameters and high values of the concordance correlation coefficient (CCC) were found for most pharmacokinetic parameters in inter-/intraobserver comparison and slice comparison, with the exception of the parameter A before therapy in intra-/ interobserver comparison (CCC: 0.315/0.452) and kep before therapy in intraobserver comparison (CCC: 0.362). CONCLUSION: Our results indicate good inter- and intraobserver reproducibility for most pharmacokinetic parameters and for the two adjacent slices measured. However, as there were some parameters that demonstrated poor correlation, testing for reproducibility and a multiobserver approach might be considered whenever using pharmacokinetic parameters as biomarkers.

Rectal cancer: dynamic contrast-enhanced MRI correlates with lymph node status and epidermal growth factor receptor expression.

PURPOSE: To evaluate correlations between dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and clinicopathologic data as well as immunostaining of the markers of angiogenesis epidermal growth factor receptor (EGFR) and CXC-motif chemokine receptor 4 (CXCR4) in patients with rectal cancer. MATERIALS AND METHODS: Presurgical DCE-MRI was performed in 41 patients according to a standardized protocol. Two quantitative parameters (k21 , A) were derived from a pharmacokinetic two-compartment model, and one semiquantitative parameter (TTP) was assessed. Standardized surgery and histopathologic examinations were performed in all patients. Immunostaining for EGFR and CXCR4 was performed and evaluated with a standardized scoring system. RESULTS: DCE-MRI parameter A correlated significantly with the N category (P = 0.048) and k21 with the occurrence of synchronous and metachronous distant metastases (P = 0.029). A trend was shown toward a correlation between k21 and EGFR expression (P = 0.107). A significant correlation was found between DCE-MRI parameter TTP and the expression of EGFR (P = 0.044). DCE-MRI data did not correlate with CXCR4 expression. CONCLUSION: DCE-MRI is a noninvasive method which can characterize microcirculation in rectal cancer and correlates with EGFR expression. Given the relationship between the dynamic parameters and the clinicopathologic data, DCE-MRI data may constitute a prognostic indicator for lymph node and distant metastases in patients with rectal cancer.

Quantitative mapping of hemodynamics in the lung, brain, and dorsal window chamber-grown tumors using a novel, automated algorithm.

OBJECTIVE: Hemodynamic properties of vascular beds are of great interest in a variety of clinical and laboratory settings. However, there presently exists no automated, accurate, technically simple method for generating blood velocity maps of complex microvessel networks. METHODS: Here, we present a novel algorithm that addresses the problem of acquiring quantitative maps by applying pixel-by-pixel cross-correlation to video data. Temporal signals at every spatial coordinate are compared with signals at neighboring points, generating a series of correlation maps from which speed and direction are calculated. User-assisted definition of vessel geometries is not required, and sequential data are analyzed automatically, without user bias. RESULTS: Velocity measurements were validated against the dual-slit method and against in vitro capillary flow with known velocities. The algorithm was tested in three different biological models in order to demonstrate its versatility. CONCLUSIONS: The hemodynamic maps presented here demonstrate an accurate, quantitative method of analyzing dynamic vascular systems.

Traditional chinese medicine syndromes classification associates with tumor cell and microenvironment heterogeneity in colorectal cancer: a single cell RNA sequencing analysis.

BACKGROUND: Colorectal cancer (CRC) is one of the common gastrointestinal malignancies, tumor heterogeneity is the main cause of refractory CRC. Syndrome differentiation is the premise of individualized treatment of traditional Chinese medicine (TCM), but TCM syndrome lacks objective identification in CRC. This study is to investigate the correlation and significance of tumor heterogeneity and TCM syndromes classification in CRC. METHODS: In this study, we using scRNA-seq technology, investigate the significance of tumor heterogeneity in TCM syndromes classification on CRC. RESULTS: The results showed that 662 cells isolated from 11 primary CRC tumors are divided into 14 different cell clusters, and each cell subtype and its genes have different functions and signal transduction pathways, indicating significant heterogeneity. CRC tumor cell clusters have different proportions in Excess, Deficiency and Deficiency-Excess syndromes, and have their own characteristic genes, gene co-expression networks, gene functional interpretations as well as monocle functional evolution. Moreover, there were significant differences between the high expressions of MUC2, REG4, COL1A2, POSTN, SDPR, GPX1, ELF3, KRT8, KRT18, KRT19, FN1, SERPINE1, TCF4 and ZEB1 genes in Excess and Deficiency syndrome classification in CRC (P < 0.01). CONCLUSIONS: The Excess and Deficiency syndromes classification may be related to tumor heterogeneity and its microenvironment in CRC.

Contrast-enhanced Ultrasound Imaging of Antiangiogenic Tumor Therapy.

BACKGROUND/AIM: Anti-angiogenic treatment is a promising strategy for cancer therapy and is currently evaluated in clinical trials. The aim of the present study was to further investigate the effects of an anti-angiogenic therapy, inhibiting vascular endothelial growth factor (VEGF) and endothelial growth factor (EGF) using a tyrosine kinase inhibitor for blocking tumor angiogenesis and tumor progression in vivo. MATERIALS AND METHODS: Experiments were performed using C57/Bl6 mice (25 ± 5 g of body weight (b.w.)) implanted with subcutaneous Lewis lung carcinoma (LLC-1). From day 7 till 21 after tumor cell implantation, animals (n=7 per group) were treated by monotherapy using ZD6474 (50 mg/kg b.w. per os (p.o.)) daily. A control group received only the solvent polysorbate 80. Using contrast enhanced ultrasound (CE-US) parameters of intra-tumoral microcirculation animals were examined 24 h after the last application of ZD6474. Moreover, subcutaneous tumor growth was measured over the whole therapy period. Finally, histological analyses were performed to analyze the functional vessel density in the tumor tissue. RESULTS: ZD6474 reduced tumor growth of LLC-1 in C57/Bl6 mice significantly. A significant difference of maximal signal intensity (ΔSImax) and area below the intensity time curve (AUC) after antiangiogenic therapy was recorded in the tumor center by CE-US. Vessel density after hematoxyline and eosin, as well as CD31, staining showed no significant difference in both groups. CONCLUSION: Anti-angiogenic effects can be quantitatively demonstrated using CE-US imaging, which represents the spreading of efficient vessels in the tumor tissue, especially in the tumor center.

Monitoring parotid gland tumors with a new perfusion software for contrast-enhanced ultrasound.

PURPOSE: Contrast enhanced ultrasound (CE-US) is a promising imaging modality for non-invasive analysis of functional vascularisation. Lesions of the parotid gland are associated with a vascularisation that differs from normal gland tissue. The aim of this clinical study was to further analyse the perfusion in parotid gland lesions with CE-US. The new quantification software VueBox (Bracco, Italy) was used to assess the perfusion, based on DICOM datasets of CE-US examination. MATERIALS AND METHODS: CE-US measurements were performed by intravenous application of a contrast agent (SonoVue, Bracco, Italy) before surgical tumor resection. From the analysis of a time sequence of 2D DICOM contrast images, area under time intensity curve (AUC), peak enhancement (PE), wash-in-rate (WiR) and wash-in-perfusion-index (WiPI) were calculated using VueBox. These were correlated with the histological analyses of the tumor tissue. RESULTS: Significant difference of area below intensity time curve (AUC), peak enhancement (PE), wash-in-rate (WiR) and wash-in perfusion index (WiPI) were observed in the malign lesions compared to benign tumors (p < 0,05) and in pleomorphic adenoma compared to cystadenolymphoma (p < 0,05). CONCLUSION: CE-US seems to be a quantitative and independent method for discriminating between malign and benign parotid gland tumors.

Targeting tumor microenvironment: crossing tumor interstitial fluid by multifunctional nanomedicines.

INTRODUCTION: The genesis of cancer appears to be a complex matter, which is not simply based upon few genetic abnormalities/alteration. In fact, irregular microvasculature and aberrant interstitium of solid tumors impose significant pathophysiologic barrier functions against cancer treatment modalities, hence novel strategies should holistically target bioelements of tumor microenvironment (TME). In this study, we provide some overview and insights on TME and important strategies used to control the impacts of such pathophysiologic barriers. METHODS: We reviewed all relevant literature for the impacts of tumor interstitium and microvasculature within the TME as well as the significance of the implemented strategies. RESULTS: While tumorigenesis initiation seems to be in close relation with an emergence of hypoxia and alterations in epigenetic/genetic materials, large panoplies of molecular events emerge as intricate networks during oncogenesis to form unique lenient TME in favor of tumor progression. Within such irregular interstitium, immune system displays defective surveillance functionalities against malignant cells. Solid tumors show multifacial traits with coadaptation and self-regulation potentials, which bestow profound resistance against the currently used conventional chemotherapy and immunotherapy agents that target solely one face of the disease. CONCLUSION: The cancerous cells attain unique abilities to form its permissive microenvironment, wherein (a) extracellular pH is dysregulated towards acidification, (b) extracellular matrix (ECM) is deformed, (c) stromal cells are cooperative with cancer cells, (d) immune system mechanisms are defective, (e) non-integrated irregular microvasculature with pores (120-1200 nm) are formed, and (h) interstitial fluid pressure is high. All these phenomena are against cancer treatment modalities. As a result, to control such abnormal pathophysiologic traits, novel cancer therapy strategies need to be devised using multifunctional nanomedicines and theranostics.

Radiation-induced changes in microcirculation and interstitial fluid pressure affecting the delivery of macromolecules and nanotherapeutics to tumors.

The immature, chaotic microvasculature of most solid tumors can present a significant impediment to blood-borne delivery, uneven distribution, and compromised penetration of macromolecular anticancer drugs and diagnostic agents from tumor microvessels across the interstitial space to cancer cells. To reach viable tumor cells in relevant concentrations, macromolecular agents are confronted with several barriers to vascular, transvascular, and interstitial transport. Amongst those (1) heterogeneous and poor blood supply, (2) distinctly reduced or even abolished hydrostatic and oncotic pressure gradients across the microvessel wall abrogating the convective transport from the vessel lumen into the interstitial space (impairment of transvascular transport), and (3) impediment of convective transport within the interstitial compartment due to elevated interstitial fluid pressure (IFP) (resulting from hyperpermeable blood vessels coupled with non-functional lymphatics) and a dense structure of the interstitial matrix are the major mechanisms hindering drug delivery. Upon irradiation, changes in these barrier functions are inconclusive so far. Alterations in vascular transport properties following fractionated radiation up to 40 Gy are quite inconsistent in terms of direction, extent, and time course. Total doses above 45 Gy can damage tumor microvessels, additionally impeding vascular delivery. Vascular permeability for macromolecules might be enhanced up to a total dose of 45 Gy. However, this effect is counteracted/abolished by the elevated IFP in solid tumors. When assessing IFP during fractionated radiotherapy in patient tumors, inconsistent alterations have been observed, both in direction and extent. From these data it is concluded that modulations in vascular, transvascular, and interstitial transport by irradiation of solid tumors are rather unclear so far. Translation of experimental data into the clinical setting thus needs to be undertaken with especial care.

Delivery of molecular and cellular medicine to solid tumors.

To reach cancer cells in a tumor, a blood-borne therapeutic molecule or cell must make its way into the blood vessels of the tumor and across the vessel wall into the interstitium, and finally migrate through the interstitium. Unfortunately, tumors often develop in ways that hinder each of these steps. Our research goals are to analyze each of these steps experimentally and theoretically, and then integrate the resulting information in a unified theoretical framework. This paradigm of analysis and synthesis has allowed us to obtain a better understanding of physiological barriers in solid tumors, and to develop novel strategies to exploit and/or to overcome these barriers for improved cancer detection and treatment.