Molecular Imaging in Pancreatic Cancer - A Roadmap for Therapeutic Decisions

Pancreatic ductal adenocarcinoma (PDAC) is a deadly cancer characterized by multiple molecular alterations, the presence of an intense stroma, poor perfusion, and resistance to therapy. In addition to standard imaging techniques, experimental imaging strategies, such as those utilizing molecular probes, nanoparticle-based agents, and tagged antibodies are actively being explored experimentally. It is hoped that advances in these technologies will allow for detecting PDAC at an early stage, and could serve to validate experimental therapies, rapidly identify non-responders, and assist in the design of novel therapeutic strategies tailored to the patient’s molecular profile

Diagnostic and Therapeutic Biomarkers in Glioblastoma: Current Status and Future Perspectives

Glioblastoma (GBM) is a primary neuroepithelial tumor of the central nervous system, characterized by an extremely aggressive clinical phenotype. Patients with GBM have a poor prognosis and only 3–5% of them survive for more than 5 years. The current GBM treatment standards include maximal resection followed by radiotherapy with concomitant and adjuvant therapies. Despite these aggressive therapeutic regimens, the majority of patients suffer recurrence due to molecular heterogeneity of GBM. Consequently, a number of potential diagnostic, prognostic, and predictive biomarkers have been investigated. Some of them, such as IDH mutations, 1p19q deletion, MGMT promoter methylation, and EGFRvIII amplification are frequently tested in routine clinical practice. With the development of sequencing technology, detailed characterization of GBM molecular signatures has facilitated a more personalized therapeutic approach and contributed to the development of a new generation of anti-GBM therapies such as molecular inhibitors targeting growth factor receptors, vaccines, antibody-based drug conjugates, and more recently inhibitors blocking the immune checkpoints. In this article, we review the exciting progress towards elucidating the potential of current and novel GBM biomarkers and discuss their implications for clinical practice

Near-infrared photoimmunotherapy targeting EGFR-Shedding new light on glioblastoma treatment

Glioblastomas (GBMs) are high-grade brain tumors, differentially driven by alterations (amplification, deletion or missense mutations) in the epidermal growth factor receptor (EGFR), that carry a poor prognosis of just 12–15 months following standard therapy. A combination of interventions targeting tumor-specific cell surface regulators along with convergent downstream signaling pathways may enhance treatment efficacy. Against this background, we investigated a novel photoimmunotherapy approach combining the cytotoxicity of photodynamic therapy with the specificity of immunotherapy. An EGFR-specific affibody (ZEGFR:03115) was conjugated to the phthalocyanine dye, IR700DX, which when excited with near-infrared light produces a cytotoxic response. ZEGFR:03115–IR700DX EGFR-specific binding was confirmed by flow cytometry and confocal microscopy. The conjugate showed effective targeting of EGFR positive GBM cells in the brain. The therapeutic potential of the conjugate was assessed both in vitro, in GBM cell lines and spheroids by the CellTiter-Glo® assay, and in vivo using subcutaneous U87-MGvIII xenografts. In addition, mice were imaged pre- and post-PIT using the IVIS/Spectrum/CT to monitor treatment response. Binding of the conjugate correlated to the level of EGFR expression in GBM cell lines. The cell proliferation assay revealed a receptor-dependent response between the tested cell lines. Inhibition of EGFRvIII+ve tumor growth was observed following administration of the immunoconjugate and irradiation. Importantly, this response was not seen in control tumors. In conclusion, the ZEGFR:03115–IR700DX showed specific uptake in vitro and enabled imaging of EGFR expression in the orthotopic brain tumor model. Moreover, the proof-of-concept in vivo PIT study demonstrated therapeutic efficacy of the conjugate in subcutaneous glioma xenografts

Short-wave infrared imaging enables high-contrast fluorescence-guided surgery in neuroblastoma

Fluorescence-guided surgery is set to play a pivotal role in the intraoperative management of pediatric tumors. Short-wave infrared imaging (SWIR) has advantages over conventional near-infrared I (NIR-I) imaging with reduced tissue scattering and autofluorescence. Here, two NIR-I dyes (IRDye800CW and IR12), with long tails emitting in the SWIR range, were conjugated with a clinical-grade anti-GD2 monoclonal antibody (Dinutuximab-beta) to compare NIR-I and SWIR imaging for neuroblastoma surgery. A first-of-its-kind multispectral NIR-I/SWIR fluorescence imaging device was constructed to allow an objective comparison between the two imaging windows. Conjugates were first characterized in vitro. Tissue-mimicking phantoms, imaging specimens of known geometric and material composition, were used to assess the sensitivity and depth penetration of the NIR-I/SWIR device, showing a minimum detectable volume of ~0.9 mm3 and depth penetration up to 3 mm. In vivo, fluorescence imaging using the NIR-I/SWIR device showed a high tumor-to-background ratio (TBR) for both dyes, with anti-GD2-IR800 being significantly brighter than anti-GD2-IR12. Crucially, the system enabled higher TBR at SWIR wavelengths than at NIR-I wavelengths, verifying SWIR imaging enables high-contrast delineation of tumor margins. This work demonstrates that by combining the high-specificity of anti-GD2 antibodies with the availability and translatability of existing NIR-I dyes, along with the advantages of SWIR in terms of depth and tumor signal-to-background ratio, GD2-targeted NIR-I/SWIR-guided surgery could improve the treatment of neuroblastoma patients, warranting investigation in future clinical trials

Modular Synthesis of Semiconducting Graft Co-polymers to Achieve "clickable" Fluorescent Nanoparticles with Long Circulation and Specific Cancer Targeting

Semiconducting polymer nanoparticles (SPNs) have been explored for applications in cancer theranostics because of their high absorption coefficients, photostability and biocompatibility. However, SPNs are susceptible to aggregation and protein fouling in physiological conditions, which can be detrimental for in vivo applications. Here, we describe a method for achieving colloidally stable and low-fouling SPNs by grafting PEG onto the backbone of the fluorescent semiconducting polymer, poly(9,9'-dioctylfluorene-5-fluoro-2,1,3-benzothiadiazole) (F8BT-F), in a simple one-step substitution reaction, post-polymerisation. Further, by utilising azide-functionalised PEG we site-specifically "click" anti-HER2 antibodies, Fab fragments, or affibodies onto the SPN surface, which allows the functionalised SPNs to specifically target HER2-positive cancer cells. In vivo, our PEGylated SPNs were found to have excellent circulation efficiencies in zebrafish embryos for up to seven days post-injection. SPNs functionalised with affibodies were then shown to be able to target HER2 expressing cancer cells in a zebrafish xenograft model. The covalent PEGylated SPN system described herein shows great potential for cancer theranostics. This article is protected by copyright. All rights reserved

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms