Electrospun Poly(vinyl alcohol)-Based Conductive Semi-interpenetrating Polymer Network Fibrous Hydrogel: A Toolbox for Optimal Cross-Linking.

Cross-linking of poly(vinyl alcohol) (PVA) creates a three-dimensional network by bonding adjacent polymer chains. The cross-linked structure, upon immersion in water, turns into a hydrogel, which exhibits unique absorption properties due to the presence of hydrophilic groups within the PVA polymer chains and, simultaneously, ceases to be soluble in water. The properties of PVA can be adjusted by chemical modification or blending with other substances, such as polymers, e.g., conductive poly[3-(potassium-5-butanoate)thiophene-2,5-diyl] (P3KBT). In this work, PVA-based conductive semi-interpenetrating polymer networks (semi-IPNs) are successfully fabricated. The systems are obtained as a result of electrospinning of PVA/P3KBT precursor solutions with different polymer concentrations and then cross-linking using "green", environmentally safe methods. One approach consists of thermal treatment (H), while the second approach combines stabilization with ethanol and heating (E). The comprehensive characterization allows to evaluate the correlation between the cross-linking methods and properties of nanofibrous hydrogels. While both methods are successful, the cross-linking density is higher in the thermally cross-linked samples, resulting in lower conductivity and swelling ratio compared to the E-treated samples. Moreover, the H-cross-linked systems have better mechanical properties-lower stiffness and greater tensile strength. All the tested systems are biocompatible, and interestingly, due to the presence of P3KBT, they show photoresponsivity to solar radiation generated by the simulator. The results indicate that both methods of PVA cross-linking are highly effective and can be applied to a specific system depending on the target, e.g., biomedical or electronic applications.

Follicular Lymphoma Microenvironment Traits Associated with Event-Free Survival.

The majority of patients with Follicular Lymphoma (FL) experience subsequent phases of remission and relapse, making the disease "virtually" incurable. To predict the outcome of FL patients at diagnosis, various clinical-based prognostic scores have been proposed; nonetheless, they continue to fail for a subset of patients. Gene expression profiling has highlighted the pivotal role of the tumor microenvironment (TME) in the FL prognosis; nevertheless, there is still a need to standardize the assessment of immune-infiltrating cells for the prognostic classification of patients with early or late progressing disease. We studied a retrospective cohort of 49 FL lymph node biopsies at the time of the initial diagnosis using pathologist-guided analysis on whole slide images, and we characterized the immune repertoire for both quantity and distribution (intrafollicular, IF and extrafollicular, EF) of cell subsets in relation to clinical outcome. We looked for the natural killer (CD56), T lymphocyte (CD8, CD4, PD1) and macrophage (CD68, CD163, MA4A4A)-associated markers. High CD163/CD8 EF ratios and high CD56/MS4A4A EF ratios, according to Kaplan-Meier estimates were linked with shorter EFS (event-free survival), with the former being the only one associated with POD24. In contrast to IF CD68+ cells, which represent a more homogeneous population, higher in non-progressing patients, EF CD68+ macrophages did not stratify according to survival. We also identify distinctive MS4A4A+CD163-macrophage populations with different prognostic weights. Enlarging the macrophage characterization and combining it with a lymphoid marker in the rituximab era, in our opinion, may enable prognostic stratification for low-/high-grade FL patients beyond POD24. These findings warrant validation across larger FL cohorts.

Combining preclinical tools and models to unravel tumor complexity: Jump into the next dimension.

Tumors are complex and heterogeneous diseases characterized by an intricate milieu and dynamically in connection with surrounding and distant tissues. In the last decades, great efforts have been made to develop novel preclinical models able to recapitulate the original features of tumors. However, the development of an in vitro functional and realistic tumor organ is still utopic and represents one of the major challenges to reproduce the architecture of the tumor ecosystem. A strategy to decrypt the whole picture and predict its behavior could be started from the validation of simplified biomimetic systems and then proceed with their integration. Variables such as the cellular and acellular composition of tumor microenvironment (TME) and its spatio-temporal distribution have to be considered in order to respect the dynamic evolution of the oncologic disease. In this perspective, we aim to explore the currently available strategies to improve and integrate in vitro and in vivo models, such as three-dimensional (3D) cultures, organoids, and zebrafish, in order to better understand the disease biology and improve the therapeutic approaches.

Pro-inflammatory RNA:DNA Hybrids Are p53 Independently Boosted by Hyperbaric Oxygen: a Subcellular Distribution Analysis by Automated Quantitative Imaging.

PURPOSE: RNA:DNA hybrids are co-transcriptional products with acknowledged cytoplasmic pro-inflammatory role as activators of the cGAS-STING pathway. We recently proved them also as radiation-induced senescence messages for the abscopal effect mediation, demonstrating the need for a functional p53 for their production and release in A549 and H1299 tumour cells. However, little is known about their role under different stress conditions, especially in cancer cells. METHODS: In this work, we open the investigation making use of automated quantitative imaging to characterize the hybrid subcellular distribution in HeLa cells grown under different oxygen pressures or exposed to different ionizing radiation doses. After cell imaging by confocal fluorescent microscopy, we apply automated imaging methods developed on purpose to quantify hybrid foci and nuclear cluster intensity, regional and local density and dimension. RESULTS: We show that alteration of culture oxygenation increases hybrid cytoplasmic presence, especially when caused by an hyperoxic environment, with evident hybrid gathering at the cell membrane. Ionizing radiations always fail to increase hybrids, in accordance with the absence of functional p53 in HeLa cells. However, dose-dependent effects are still evident and suggest a threshold dose of 7.5 Gy for remarkable hybrid reduction. CONCLUSION: Together with our previous results, these data demonstrate for the first time that different types of stress can increase hybrid production in cancer cells and by at least two different pathways, one p53-dependent triggerable by ionizing radiations and one p53-independent triggerable by oxidative stress. Together, our findings provide a starting point for understanding hybrid role in tumour stress response.

KRAS mutation predict response and outcome in advanced non-small cell lung carcinoma without driver alterations receiving PD-1 blockade immunotherapy combined with platinum-based chemotherapy: a retrospective cohort study from China.

Background: The selection of patients for immunotherapy remains challenging given the lack of highly specific and highly sensitive biomarkers. Kirsten rat sarcoma (KRAS) mutation is the most frequent molecular alteration found in advanced non-small cell lung carcinoma (NSCLC). We explored whether KRAS mutation status predicted the effects of first-line immune checkpoint inhibitor (ICI) treatment and platinum-based chemotherapy in Chinese patients with advanced NSCLC. Methods: Clinical data were extracted from medical records of patients with advanced NSCLC at the First Affiliated Hospital of Guangzhou Medical University in China between January 2019 and March 2020. Overall survival (OS) and progression-free survival (PFS) rates were compared via log-rank tests, and independent prognostic factors were identified via Cox regression. Results: Patients with advanced NSCLC without driver alterations who were treated with ICI and platinum-based chemotherapy (N=80) were identified, including 28.7% with KRAS mutations and 71.3% with non-KRAS mutations. Tumor programmed death-ligand 1 (PD-L1) expression was analyzed using a 1% cutoff, and 32.5% of patients were negative and 67.5% were positive. The median tumor mutational burden (TMB) was 7.29 mutations per megabase (muts/Mb) (range, 0.08-44.8 muts/Mb), with 32.5% of cases <5 muts/Mb and 67.5% ≥5 muts/Mb. The median PFS and OS for the entire cohort were 9.8 (95% CI: 9.1-10.5) and 17.6 (95% CI: 14.4-20.8) months, respectively. The 6-month PFS rate was 67.5% and the 1-year OS rate was 72.5%. Thirty-five patients survived until the last follow-up. The OS and PFS of patients with KRAS mutations were significantly higher than those in the non-KRAS mutant group (P<0.05). The Cox multivariate analyses showed that brain metastasis [hazard ratio (HR) =0.232, 95% CI: 0.102-0.530; P=0.001], TMB (HR =5.675, 95% CI: 1.948-16.535; P=0.001), KRAS mutation (HR =2.552, 95% CI: 1.141-5.708; P=0.023) were independent predictors of OS in patients treated with ICIs and platinum-based chemotherapy. Liver metastasis (HR =0.344, 95% CI: 0.191-0.619; P<0.001) and KRAS/tumor protein p53 (TP53) co-mutation (HR =0.220, 95% CI: 0.067-0.725; P=0.013) were the prognostic factor for PFS of qualified patients. Conclusions: This work provides evidence that KRAS mutation in advanced NSCLC may be served as a potential predictive biomarker for immunotherapeutic efficacy.

Emerging roles of purinergic signaling in anti-cancer therapy resistance.

Cancer is a complex disease with a rapid growing incidence and often characterized by a poor prognosis. Although impressive advances have been made in cancer treatments, resistance to therapy remains a critical obstacle for the improvement of patients outcome. Current treatment approaches as chemo-, radio-, and immuno-therapy deeply affect the tumor microenvironment (TME), inducing an extensive selective pressure on cancer cells through the activation of the immune system, the induction of cell death and the release of inflammatory and damage-associated molecular patterns (DAMPS), including nucleosides (adenosine) and nucleotides (ATP and ADP). To survive in this hostile environment, resistant cells engage a variety of mitigation pathways related to metabolism, DNA repair, stemness, inflammation and resistance to apoptosis. In this context, purinergic signaling exerts a pivotal role being involved in mitochondrial function, stemness, inflammation and cancer development. The activity of ATP and adenosine released in the TME depend upon the repertoire of purinergic P2 and adenosine receptors engaged, as well as, by the expression of ectonucleotidases (CD39 and CD73) on tumor, immune and stromal cells. Besides its well established role in the pathogenesis of several tumors and in host-tumor interaction, purinergic signaling has been recently shown to be profoundly involved in the development of therapy resistance. In this review we summarize the current advances on the role of purinergic signaling in response and resistance to anti-cancer therapies, also describing the translational applications of combining conventional anticancer interventions with therapies targeting purinergic signaling.

Why the complications of COVID-19 patients differ in elderly and young cancer patients.

Zhang et al. reported the impact of different risk factors and comorbidities in COVID-19 lethality. The authors observed that the odds of dying by COVID-19 in cancer patients decrease with age and cancer becomes a non-significant factor above 80 years. We speculate on the possible causes for the different COVID-19 severity between elderly and young patients. Several factors that can have a different impact on young and elderly have to be taken into account such as inflammation, microbiota and anti-cancer therapies. Inflammaging is a complex process that characterizes elderly people and it is believed to contribute to the severity of COVID-19 associated with old age. Cancer and related therapies may alter the process of inflammaging both quantitatively and qualitatively and could impact on COVID-19 severity. Moreover, therapies used in elderly cancer patients are usually different from that used for young people where the presence of comorbidities and the mechanisms of action of the different drugs both on the susceptibility genes and on other factors have to be considered. Sex hormones and anti-estrogen therapies affect significantly gene expression in target cells thereby modulating the susceptibility of the tissues to SARS-CoV-2 infection and as a consequence the extent of the symptoms. The concentration of sex hormones varies with aging and among sexes. Interestingly, recent evidences, further corroborate the hypothesis that also sex hormones or anti-estrogen therapies impact the susceptibility to COVID-19 and its severity.

TROP2 (trophoblast cell-surface antigen 2): a drug target for breast cancer.

INTRODUCTION: Breast cancer (BC) is the most common diagnosed cancer and the second leading cause of cancer-associated death in women, with the triple negative (TNBC) subtype being characterized by the poorest prognosis. New therapeutic targets are urgently needed to overcome the high metastatic potential, aggressiveness and poor survival of these tumors. Trop2 transmembrane glycoprotein, acting as an intracellular calcium signal transducer, recently emerged as a new potential target in epithelial cancers, in particular in breast cancer. AREAS COVERED: We summarize the key features of Trop2 structure and function, describing the therapeutic strategies targeting this protein in cancer. Particular attention is paid to antibody-drug conjugates (ADCs), actually representing the most successful strategy. EXPERT OPINION: ADCs targeting Trop2 recently received an accelerated FDA approval for the therapy of metastatic TNBC. The prospects for these novel ADCs in BC subtypes other than TNBC are discussed, taking into account the main pitfalls relative to Trop2 structure and function.

Emerging Roles of Aldehyde Dehydrogenase Isoforms in Anti-cancer Therapy Resistance.

Aldehyde dehydrogenases (ALDHs) are a family of detoxifying enzymes often upregulated in cancer cells and associated with therapeutic resistance. In humans, the ALDH family comprises 19 isoenzymes active in the majority of mammalian tissues. Each ALDH isoform has a specific differential expression pattern and most of them have individual functional roles in cancer. ALDHs are overexpressed in subpopulations of cancer cells with stem-like features, where they are involved in several processes including cellular proliferation, differentiation, detoxification and survival, participating in lipids and amino acid metabolism and retinoic acid synthesis. In particular, ALDH enzymes protect cancer cells by metabolizing toxic aldehydes in less reactive and more soluble carboxylic acids. High metabolic activity as well as conventional anticancer therapies contribute to aldehyde accumulation, leading to DNA double strand breaks (DSB) through the generation of reactive oxygen species (ROS) and lipid peroxidation. ALDH overexpression is crucial not only for the survival of cancer stem cells but can also affect immune cells of the tumour microenvironment (TME). The reduction of ROS amount and the increase in retinoic acid signaling impairs immunogenic cell death (ICD) inducing the activation and stability of immunosuppressive regulatory T cells (Tregs). Dissecting the role of ALDH specific isoforms in the TME can open new scenarios in the cancer treatment. In this review, we summarize the current knowledge about the role of ALDH isoforms in solid tumors, in particular in association with therapy-resistance.

Irradiation causes senescence, ATP release, and P2X7 receptor isoform switch in glioblastoma.

Glioblastoma (GBM) is the most lethal brain tumor in adults. Radiation, together with temozolomide is the standard treatment, but nevertheless, relapse occurs in nearly all cases. Understanding the mechanisms underlying radiation resistance may help to find more effective therapies. After radiation treatment, ATP is released into the tumor microenvironment where it binds and activates purinergic P2 receptors, mainly of the P2X7 subtype. Two main P2X7 splice variants, P2X7A and P2X7B, are expressed in most cell types, where they associate with distinct biochemical and functional responses. GBM cells widely differ for the level of P2X7 isoform expression and accordingly for sensitivity to stimulation with extracellular ATP (eATP). Irradiation causes a dramatic shift in P2X7 isoform expression, with the P2X7A isoform being down- and the P2X7B isoform up-modulated, as well as extensive cell death and overexpression of stemness and senescence markers. Treatment with P2X7 blockers during the post-irradiation recovery potentiated irradiation-dependent cytotoxicity, suggesting that P2X7B activation by eATP generated a trophic/growth-promoting stimulus. Altogether, these data show that P2X7A and B receptor isoform levels are inversely modulated during the post-irradiation recovery phase in GBM cells.

Extracellular ATP is increased by release of ATP-loaded microparticles triggered by nutrient deprivation.

Rationale: Caloric restriction improves the efficacy of anti-cancer therapy. This effect is largely dependent on the increase of the extracellular ATP concentration in the tumor microenvironment (TME). Pathways for ATP release triggered by nutrient deprivation are largely unknown. Methods: The extracellular ATP (eATP) concentration was in vivo measured in the tumor microenvironment of B16F10-inoculated C57Bl/6 mice with the pmeLuc probe. Alternatively, the pmeLuc-TG-mouse was used. Caloric restriction was in vivo induced with hydroxycitrate (HC). B16F10 melanoma cells or CT26 colon carcinoma cells were in vitro exposed to serum starvation to mimic nutrient deprivation. Energy metabolism was monitored by Seahorse. Microparticle release was measured by ultracentrifugation and by Nanosight. Results: Nutrient deprivation increases eATP release despite the dramatic inhibition of intracellular energy synthesis. Under these conditions oxidative phosphorylation was dramatically impaired, mitochondria fragmented and glycolysis and lactic acid release were enhanced. Nutrient deprivation stimulated a P2X7-dependent release of ATP-loaded, mitochondria-containing, microparticles as well as of naked mitochondria. Conclusions: Nutrient deprivation promotes a striking accumulation of eATP paralleled by a large release of ATP-laden microparticles and of naked mitochondria. This is likely to be a main mechanism driving the accumulation of eATP into the TME.

Chronological age or biological age: What drives the choice of adjuvant treatment in elderly breast cancer patients?

Ma and colleagues reported in their study on 12,004 elderly patients published on Breast J. 2020, that adjuvant chemotherapy was not associated with overall survival. Given the toxicities associated with systemic treatments, caution recommendation or omission of chemotherapy may be considered in elderly patient selection especially when comorbidities are present. We agree with authors final conclusions but we want to highlight that to define the adjuvant therapy in BC elderly patients several factors need to be taken into account. One of the main issues is the lack of universal and unique guidelines to define elderly patients. In clinical practice it can be very difficult to estimate the benefit/risk ratio in elderly patients because chemotherapy-induced toxicity is worse than in younger individuals. For these reasons, beyond comorbidities, the choice of adjuvant therapy for elderly patients must also be based both on chronological and biological age. Moreover, the multidisciplinary team for the elderly patient evaluation should include both the geriatrician and the molecular biologist.

Tumor resident microbiota and response to therapies: An insight on tissue bacterial microbiota.

The role of the intestinal microbiota in the promotion, progression, and response to therapies is gaining importance, but recent studies confirm the presence of microbiota also in the tumor, thus becoming a component of the tumor microenvironment. There is not much knowledge on the characteristics and mechanisms of action of the tumor resident microbiota, but there are already indications of its involvement in conditioning the response to therapies. In this review, we discuss recent publications on the interaction between microbiota and anticancer treatments, mechanisms of resistance and possible strategies for manipulating the microbiota that could improve treatments in a personalized medicine perspective.

P2X7 promotes metastatic spreading and triggers release of miRNA-containing exosomes and microvesicles from melanoma cells.

Tumor growth and metastatic spreading are heavily affected by the P2X7 receptor as well as microvesicles and exosomes release into the tumor microenvironment. P2X7 receptor stimulation is known to trigger vesicular release from immune and central nervous system cells. However, P2X7 role in microvesicles and exosomes delivery from tumor cells was never analyzed in depth. Here we show that P2X7 is overexpressed in patients affected by metastatic malignant melanoma and that its expression closely correlates with reduced overall survival. Antagonism of melanoma cell-expressed P2X7 receptor inhibited in vitro anchorage-independent growth and migration and in vivo dissemination and lung metastasis formation. P2X7 stimulation triggered the release of miRNA-containing microvesicles and exosomes from melanoma cells, profoundly altering the nature of their miRNA content, as well as their dimensions and quantity. Among the more than 200 miRNAs that we found up-or-down-modulated for each vesicular fraction tested, we identified three miRNAs, miR-495-3p, miR-376c-3p, and miR-6730-3p, that were enriched in both the exosome and microvesicle fraction in a P2X7-dependent fashion. Interestingly, upon transfection, these miRNAs promoted melanoma cell growth or migration, and their vesicular release was minimized by P2X7 antagonism. Our data unveil an exosome/microvesicle and miRNA-dependent mechanism for the pro-metastatic activity of the P2X7 receptor and highlight this receptor as a suitable prognostic biomarker and therapeutic target in malignant melanoma.

MISpheroID: a knowledgebase and transparency tool for minimum information in spheroid identity.

Spheroids are three-dimensional cellular models with widespread basic and translational application across academia and industry. However, methodological transparency and guidelines for spheroid research have not yet been established. The MISpheroID Consortium developed a crowdsourcing knowledgebase that assembles the experimental parameters of 3,058 published spheroid-related experiments. Interrogation of this knowledgebase identified heterogeneity in the methodological setup of spheroids. Empirical evaluation and interlaboratory validation of selected variations in spheroid methodology revealed diverse impacts on spheroid metrics. To facilitate interpretation, stimulate transparency and increase awareness, the Consortium defines the MISpheroID string, a minimum set of experimental parameters required to report spheroid research. Thus, MISpheroID combines a valuable resource and a tool for three-dimensional cellular models to mine experimental parameters and to improve reproducibility.

A Simple Method for Compensating Harmonic Distortion in Current Transformers: Experimental Validation.

Conventional current transformers (CTs) suffer from nonlinearities due to their ferromagnetic cores. On one hand, it is well-known that severe core saturation may occur because of large overcurrents or unidirectional transient components: this may substantially impact the operation of relays. On the other hand, weaker nonlinear effects are also present during regular working conditions. In particular, the spectral content of typical current waveforms is characterized by a strong fundamental term responsible for harmonic distortion affecting the frequency components at the secondary side. In turn, this has a significant impact on the accuracy that can be reached as long as current harmonics must be monitored. The target of this work is implementing a simple signal processing technique that allows compensating for this effect. The method, characterized by extremely low computational complexity, is first introduced and validated using numerical simulations. After this, it was tested experimentally to improve the harmonic measurement capability of inductive CTs. The achieved results highlight a noticeable reduction of errors at low-order harmonics over a wide range of primary current amplitudes. It is worth noting that the black-box approach makes the technique suitable also for compensating nonlinearities introduced by current transducers based on different operating principles. Thanks to this peculiarity and to the low computational complexity, the proposed method is suitable to be employed in power quality analyzers and merging units. In this way, high-accuracy monitoring of current harmonics in power systems can be achieved, opening the way to advanced power quality management and to the location of disturbing users.

High-pressure oxygen rewires glucose metabolism of patient-derived glioblastoma cells and fuels inflammasome response.

Human glioblastoma (GBM) is one of the most feared primary malignant brain tumors. We investigated the effect of hyperbaric oxygen (HBO) on GBM patient-derived cells and on microglia cell biology (CHME-5). HBO administered to GBM cells inhibited cell proliferation, downregulated hypoxia-inducible factor 1 α (HIF-1α) expression, and induced glucose metabolism reprogramming (glucose rewiring). It also affected the ability of a cell to perpetuate its lineage, give rise to differentiated cells and interact with its environment to maintain a balance between quiescence, proliferation and regeneration (stemness features). Such an effect may be ascribable to an increase in intracellular ROS levels and to the triggering of inflammasome signaling by HBO itself through caspase1 activation. Moreover, the results obtained from the combination of HBO and radiotherapy (RT) clearly showed a radiosensitising effect of HBO on GBM cells grown in both 2D and 3D, and a radioprotective effect of HBO in CHME-5. In addition, the exposure of M0 microglia cells to exhausted medium or extracellular vesicles (EVs) of HBO-treated GBM cells upregulated the expression of pro-inflammatory cytokines IL1ß, IL6 and STAT1, whilst also downregulating the anti-inflammatory cytokine PPARγ. Collectively, these data provide a scientific rationale for the use of HBO in combination with RT for the treatment of patients with GBM.

TP53 drives abscopal effect by secretion of senescence-associated molecular signals in non-small cell lung cancer.

BACKGROUND: Recent developments in abscopal effect strongly support the use of radiotherapy for the treatment of metastatic disease. However, deeper understanding of the molecular mechanisms underlying the abscopal effect are required to best benefit a larger proportion of patients with metastasis. Several groups including ours, reported the involvement of wild-type (wt) p53 in radiation-induced abscopal effects, however very little is known on the role of wtp53 dependent molecular mechanisms. METHODS: We investigated through in vivo and in vitro approaches how wtp53 orchestrates radiation-induced abscopal effects. Wtp53 bearing (A549) and p53-null (H1299) NSCLC lines were xenotransplanted in nude mice, and cultured in 2D monolayers and 3D tumor spheroids. Extracellular vesicles (EVs) were isolated from medium cell culture by ultracentrifugation protocol followed by Nanoparticle Tracking Analysis. Gene expression was evaluated by RT-Real Time, digital qRT-PCR, and dot blot technique. Protein levels were determined by immunohistochemistry, confocal anlysis, western blot techniques, and immunoassay. RESULTS: We demonstrated that single high-dose irradiation (20 Gy) induces significant tumor growth inhibition in contralateral non-irradiated (NIR) A549 xenograft tumors but not in NIR p53-null H1299 or p53-silenced A549 (A549sh/p53) xenografts. We further demonstrates that irradiation of A549 cells in vitro induces a senescence-associated secretory phenotype (SASP) producing extracellular vesicles (EVs) expressing CD63 and carrying DNA:RNA hybrids and LINE-1 retrotransposon. IR-A549 EVs also hamper the colony-forming capability of recipient NIR A549 cells, induce senescent phenotype, nuclear expression of DNA:RNA hybrids, and M1 macrophage polarization. CONCLUSIONS: In our models, we demonstrate that high radiation dose in wtp53 tumors induce the onset of SASP and secretion of CD63+ EVs loaded with DNA:RNA hybrids and LINE-1 retrotransposons that convey senescence messages out of the irradiation field triggering abscopal effect in NIR tumors.