Triple blockade of EGFR, MEK and PD-L1 has antitumor activity in colorectal cancer models with constitutive activation of MAPK signaling and PD-L1 overexpression

Càncer colorectal; Resistència a inhibidors de MEK; Inhibidors de PD-L1Cáncer colorrectal; Resistencia a inhibidores de MEK; Inhibidores de PD-L1Colorectal cancer; MEK inhibitor resistance; PD-L1 inhibitorsBackground Molecular mechanisms driving acquired resistance to anti-EGFR therapies in metastatic colorectal cancer (mCRC) are complex but generally involve the activation of the downstream RAS-RAF-MEK-MAPK pathway. Nevertheless, even if inhibition of EGFR and MEK could be a strategy for overcoming anti-EGFR resistance, its use is limited by the development of MEK inhibitor (MEKi) resistance. Methods We have generated in vitro and in vivo different CRC models in order to underline the mechanisms of MEKi resistance. Results The three different in vitro MEKi resistant models, two generated by human CRC cells quadruple wild type for KRAS, NRAS, BRAF, PI3KCA genes (SW48-MR and LIM1215-MR) and one by human CRC cells harboring KRAS mutation (HCT116-MR) showed features related to the gene signature of colorectal cancer CMS4 with up-regulation of immune pathway as confirmed by microarray and western blot analysis. In particular, the MEKi phenotype was associated with the loss of epithelial features and acquisition of mesenchymal markers and morphology. The change in morphology was accompanied by up-regulation of PD-L1 expression and activation of EGFR and its downstream pathway, independently to RAS mutation status. To extend these in vitro findings, we have obtained mouse colon cancer MC38- and CT26-MEKi resistant syngeneic models (MC38-MR and CT26-MR). Combined treatment with MEKi, EGFR inhibitor (EGFRi) and PD-L1 inhibitor (PD-L1i) resulted in a marked inhibition of tumor growth in both models. Conclusions These results suggest a strategy to potentially improve the efficacy of MEK inhibition by co-treatment with EGFR and PD-L1 inhibitors via modulation of host immune responses.This research has been supported by a grant from Associazione Italiana per la Ricerca sul Cancro (AIRC) to FC (AIRC IG 18972) and and Regione Campania Cancer Research Campaign I-CURE grant to FC

The project \u201cInteractive Topography of Dante\u2019s Inferno\u201d : transfer of knowledge and design of didactic tools

The project \u201ctopography of Dante\u2019s inferno\u201d is an experiment on alternative mode of access to a complex text relying on an evident topographical structure. The artifact (a website) is designed with the aim of introducing young students (11\u201314 years old) to a text usually read and studied by older students (16\u201319 years old). The design of the artifact was based on the theories of Sinsem\ueda applied to interaction design, and the testing focused on (1) usability and (2) on the understanding of the topography of the poem as a precondition for understanding the text

Antitumor Efficacy of Dual Blockade with Encorafenib + Cetuximab in Combination with Chemotherapy in Human BRAFV600E-Mutant Colorectal Cancer

Antitumor efficacy; Chemotherapy; Colorectal cancerEficàcia antitumoral; Quimioteràpia; Càncer colorectalEficacia antitumoral; Quimioterapia; Cáncer colorrectalPurpose: Encorafenib + cetuximab (E+C) is an effective therapeutic option in chemorefractory BRAFV600E metastatic colorectal cancer (mCRC). However, there is a need to improve the efficacy of this molecular-targeted therapy and evaluate regimens suitable for untreated BRAFV600E in patients with mCRC. Experimental Design: We performed a series of in vivo studies using BRAFV600E mCRC tumor xenografts. Mice were randomized to receive 5-fluoruracil (5-FU), irinotecan, or oxaliplatin regimens (FOLFIRI or FOLFOX), (E+C) or the combination. Patients received long-term treatment until disease progression, with deescalation strategies used to mimic maintenance therapy. Transcriptomic changes after progression on cytotoxic chemotherapy or targeted therapy were assessed. Results: Antitumor activity of either FOLFIRI or E+C was better as first-line treatment as compared with second-line, with partial cross-resistance seen between a cytotoxic regimen and targeted therapy with an average 62% loss of efficacy for FOLFIRI after E+C and a 45% loss of efficacy of E+C after FOLFIRI (P < 0.001 for both). FOLFIRI-treated models had upregulation of epithelial–mesenchymal transition (EMT) and MAPK pathway activation, where E+C treated models had suppressed MAPK signaling. In contrast, with chemotherapy with E+C, EMT and MAPK signaling remained suppressed. FOLFOX or FOLFIRI, each in combination with E+C, were the most active first-line treatments as compared with E+C or to chemotherapy alone. Furthermore, FOLFOX in combination with E+C as first-line induction therapy, followed by E+C ± 5-FU as maintenance therapy, was the most effective strategy for long-term disease control. Conclusions: These results support the combination of cytotoxic chemotherapy and molecular-targeted therapy as a promising therapeutic approach in the first-line treatment of BRAFV600E mCRC.A research grant that partially covered the costs of the study was provided by Regione Campania (I-Cure Research Project, grant number: Cup 21C17000030007, to F. Ciardiello and L. Altucci). This work was also supported by Cancer Center Support Grant – Gastrointestinal Program (Project Number: 5P30 CA016672–46). O.E. Villarreal was supported by the CPRIT Training Program (RP210028)

Localization and subcellular association of Grapevine Pinot Gris Virus in grapevine leaf tissues

Despite the increasing impact of Grapevine Pinot gris disease (GPG-disease) worldwide, etiology about this disorder is still uncertain. The presence of the putative causal agent, the Grapevine Pinot Gris Virus (GPGV), has been reported in symptomatic grapevines (presenting stunting, chlorotic mottling, and leaf deformation) as well as in symptom-free plants. Moreover, information on virus localization in grapevine tissues and virus-plant interactions at the cytological level is missing at all. Ultrastructural and cytochemical investigations were undertaken to detect virus particles and the associated cytopathic effects in field-grown grapevine showing different symptom severity. Asymptomatic greenhouse-grown grapevines, which tested negative for GPGV by real time RT-PCR, were sampled as controls. Multiplex real-time RT-PCR and ELISA tests excluded the presence of viruses included in the Italian certification program both in field-grown and greenhouse-grown grapevines. Conversely, evidence was found for ubiquitous presence of Grapevine Rupestris Stem Pitting-associated Virus (GRSPaV), Hop Stunt Viroid (HSVd), and Grapevine Yellow Speckle Viroid 1 (GYSVd-1) in both plant groups. Moreover, in every field-grown grapevine, GPGV was detected by real-time RT-PCR. Ultrastructural observations and immunogold labelling assays showed filamentous flexuous viruses in the bundle sheath cells, often located inside membrane-bound organelles. No cytological differences were observed among field-grown grapevine samples showing different symptom severity. GPGV localization and associated ultrastructural modifications are reported and discussed, in the perspective of assisting management and control of the disease. \ua9 2017 The Author(s

Sinsemia as a tool for designing interactive artifacts for teaching. The case study of The topography of Dante’s Inferno and the detailed definition of reference frame

“The Topography of Dante’s Inferno” is a synsemic interactive artifact which is designed for 11-14 years old students. The design process has been based on the fundamental concepts of synsemia, which lead to an artifact that includes and combines different didactic mediators; in particular, in this article is described more in detail the fundamental concept of reference frame. The reference frame can be described as the frame (consisting of graphic elements) which allows to contextualize the graphic elements of a synsemic text. The artifact has been qualitatively evaluated in two focus groups (one with 12 teachers in training and one with 12 teachers in service), in which some reflections emerged, like some misinterpretations due to a more or less correct design of the reference frame and the didactic mediators

Agroinoculation of Grapevine Pinot Gris Virus in tobacco and grapevine provides insights on viral pathogenesis

The Grapevine Pinot Gris disease (GPG-d) is a novel disease characterized by symptoms such as leaf mottling and deformation, which has been recently reported in grapevines, and mostly in Pinot gris. Plants show obvious symptoms at the beginning of the growing season, while during summer symptom recovery frequently occurs, manifesting as symptomless leaves. A new Trichovirus, named Grapevine Pinot gris virus (GPGV), which belongs to the family Betaflexiviridae was found in association with infected plants. The detection of the virus in asymptomatic grapevines raised doubts about disease aetiology. Therefore, the primary target of this work was to set up a reliable system for the study of the disease in controlled conditions, avoiding interfering factor(s) that could affect symptom development. To this end, two clones of the virus, pRI::GPGV-vir and pRI::GPGV-lat, were generated from total RNA collected from one symptomatic and one asymptomatic Pinot gris grapevine, respectively. The clones, which encompassed the entire genome of the virus, were used in Agrobacterium-mediated inoculation of Vitis vinifera and Nicotiana benthamiana plants. All inoculated plants developed symptoms regardless of their inoculum source, demonstrating a correlation between the presence of GPGV and symptomatic manifestations. Four months post inoculum, the grapevines inoculated with the pRI::GPGV-lat clone developed asymptomatic leaves that were still positive to GPGV detection. Three to four weeks later (i.e. ca. 5 months post inoculum), the same phenomenon was observed in the grapevines inoculated with pRI::GPGV-vir. This observation perfectly matches symptom progression in infected field-grown grapevines, suggesting a possible role for plant antiviral mechanisms, such as RNA silencing, in the recovery process.</div

Influence of Irradiance, Flow Rate, Reactor Geometry, and Photopromoter Concentration in Mineralization Kinetics of Methane in Air and in Aqueous Solutions by Photocatalytic Membranes Immobilizing Titanium Dioxide

Photomineralization of methane in air (10.0–1000 ppm (mass/volume) of C) at100%relative humidity (dioxygen as oxygen donor) was systematically studied at318±3 K in an annular laboratory-scale reactor by photocatalytic membranes immobilizing titanium dioxide as a function of substrate concentration, absorbed power per unit length of membrane, reactor geometry, and concentration of a proprietary vanadium alkoxide as photopromoter. Kinetics of both substrate disappearance, to yield intermediates, and total organic carbon (TOC) disappearance, to yield carbon dioxide, were followed. At a fixed value of irradiance (0.30 W⋅cm-1), the mineralization experiments in gaseous phase were repeated as a function of flow rate (4–400 m3⋅h−1). Moreover, at a standard flow rate of 300 m3⋅h−1, the ratio between the overall reaction volume and the length of the membrane was varied, substantially by varying the volume of reservoir, from and to which circulation of gaseous stream took place. Photomineralization of methane in aqueous solutions was also studied, in the same annular reactor and in the same conditions, but in a concentration range of 0.8–2.0 ppm of C, and by using stoichiometric hydrogen peroxide as an oxygen donor. A kinetic model was employed, from which, by a set of differential equations, four final optimised parameters,k1andK1,k2andK2, were calculated, which is able to fit the whole kinetic profile adequately. The influence of irradiance onk1andk2, as well as of flow rate onK1andK2, is rationalized. The influence of reactor geometry onkvalues is discussed in view of standardization procedures of photocatalytic experiments. Modeling of quantum yields, as a function of substrate concentration and irradiance, as well as of concentration of photopromoter, was carried out very satisfactorily. Kinetics of hydroxyl radicals reacting between themselves, leading to hydrogen peroxide, other than with substrate or intermediates leading to mineralization, were considered, and it is paralleled by a second competition kinetics involving superoxide radical anion

Retrospective Study of Regorafenib Versus TAS-102 Efficacy and Safety in Chemorefractory Metastatic Colorectal Cancer (mCRC) Patients: A Multi-institution Real Life Clinical Data

INTRODUCTION: There have been significant developments in colorectal cancer (CRC) research over the last few years, with the introduction of new agents that have been prolonged median overall survival of metastatic colorectal cancer (mCRC). These therapies have improved patient outcomes; however, despite significant progress in strategies for cancer treatment, their use is limited by development of resistant mechanism. Almost 30% of patients with refractory mCRC will remain good candidates for further treatment. Regorafenib and TAS-102 are novel antitumor agents for patients with refractory mCRC. However, it is unclear which patients may derive a survival benefit from these drugs in real-life clinical practice.; METHODS: We performed a retrospective analysis evaluating safety and efficacy of TAS-102 and regorafenib in a cohort of refractory mCRC patients, in 3 different centers between January 1 2018 and May 31 2020, with the aim of assessing the optimal sequence treatment for these 2 drugs.; RESULTS: One hundred and forty mCRC patients were included in the analysis. Of these patients, 64 received regorafenib and 76 received TAS-102 as first treatment. After progression, in the regorafenib 24 (37%) patients switched to secondary treatment with TAS-102, instead, in the TAS-102 group, among 76 patients, 29 (45%) patients switched to secondary treatment with regorafenib. Disease control was achieved in 8 (12.5%) of 64 patients in the regorafenib group and 17 (22.4%) of 76 patients in the TAS-102 group. In terms of efficacy, the PFS and OS were similar in both treatment groups for primary and secondary treatments. AEs reported in this analysis were mostly consistent with the known safety profiles of regorafenib and TAS-102 in previous clinical trials.; CONCLUSION: The present study is the first one to compare the activity of the two agents in a large cohort of chemo-refractory mCRC patients providing more details about the best sequence, to be incorporated in clinical practice. Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved

Receptor tyrosine kinase-dependent PI3K activation is an escape mechanism to vertical suppression of the EGFR/RAS/MAPK pathway in KRAS-mutated human colorectal cancer cell lines

Abstract BACKGROUND: Previous studies showed that the combination of an anti-Epidermal growth factor (EGFR) and a MEK-inhibitor is able to prevent the onset of resistance to anti-EGFR monoclonal antibodies in KRAS-wild type colorectal cancer (CRC), while the same combination reverts anti-EGFR primary resistance in KRAS mutated CRC cell lines. However, rapid onset of resistance is a limit to combination therapies in KRAS mutated CRC. METHODS: We generated four different KRAS mutated CRC cell lines resistant to a combination of cetuximab (an anti-EGFR antibody) and refametinib (a selective MEK-inhibitor) after continuous exposure to increasing concentration of the drugs. We characterized these resistant cell lines by evaluating the expression and activation status of a panel of receptor tyrosine kinases (RTKs) and intracellular transducers by immunoblot and qRT-PCR. Oncomine comprehensive assay and microarray analysis were carried out to investigate new acquired mutations or transcriptomic adaptation, respectively, in the resistant cell lines. Immunofluorescence assay was used to show the localization of RTKs in resistant and parental clones. RESULTS: We found that PI3K-AKT pathway activation acts as an escape mechanism in cell lines with acquired resistance to combined inhibition of EGFR and MEK. AKT pathway activation is coupled to the activation of multiple RTKs such as HER2, HER3 and IGF1R, though its pharmacological inhibition is not sufficient to revert the resistant phenotype. PI3K pathway activation is mediated by autocrine loops and by heterodimerization of multiple receptors. CONCLUSIONS: PI3K activation plays a central role in the acquired resistance to the combination of anti-EGFR and MEK-inhibitor in KRAS mutated colorectal cancer cell lines. PI3K activation is cooperatively achieved through the activation of multiple RTKs such as HER2, HER3 and IGF1R