Habitat radiomics and deep learning fusion nomogram to predict EGFR mutation status in stage I non-small cell lung cancer: a multicenter study.

Develop a radiomics nomogram that integrates deep learning, radiomics, and clinical variables to predict epidermal growth factor receptor (EGFR) mutation status in patients with stage I non-small cell lung cancer (NSCLC). We retrospectively included 438 patients who underwent curative surgery and completed driver-gene mutation tests for stage I NSCLC from four academic medical centers. Predictive models were established by extracting and analyzing radiomic features in intratumoral, peritumoral, and habitat regions of CT images to identify EGFR mutation status in stage I NSCLC. Additionally, three deep learning models based on the intratumoral region were constructed. A nomogram was developed by integrating representative radiomic signatures, deep learning, and clinical features. Model performance was assessed by calculating the area under the receiver operating characteristic (ROC) curve. The established habitat radiomics features demonstrated encouraging performance in discriminating between EGFR mutant and wild-type, with predictive ability superior to other single models (AUC 0.886, 0.812, and 0.790 for the training, validation, and external test sets, respectively). The radiomics-based nomogram exhibited excellent performance, achieving the highest AUC values of 0.917, 0.837, and 0.809 in the training, validation, and external test sets, respectively. Decision curve analysis (DCA) indicated that the nomogram provided a higher net benefit than other radiomics models, offering valuable information for treatment.

EGFR mutations induce the suppression of CD8+ T cell and anti-PD-1 resistance via ERK1/2-p90RSK-TGF-ß axis in non-small cell lung cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) patients with EGFR mutations exhibit an unfavorable response to immune checkpoint inhibitor (ICI) monotherapy, and their tumor microenvironment (TME) is usually immunosuppressed. TGF-ß plays an important role in immunosuppression; however, the effects of TGF-ß on the TME and the efficacy of anti-PD-1 immunotherapy against EGFR-mutated tumors remain unclear. METHODS: Corresponding in vitro studies used the TCGA database, clinical specimens, and self-constructed mouse cell lines with EGFR mutations. We utilized C57BL/6N and humanized M-NSG mouse models bearing EGFR-mutated NSCLC to investigate the effects of TGF-ß on the TME and the combined efficacy of TGF-ß blockade and anti-PD-1 therapy. The changes in immune cells were monitored by flow cytometry. The correlation between TGF-ß and immunotherapy outcomes of EGFR-mutated NSCLC was verified by clinical samples. RESULTS: We identified that TGF-ß was upregulated in EGFR-mutated NSCLC by EGFR activation and subsequent ERK1/2-p90RSK phosphorylation. TGF-ß directly inhibited CD8+ T cell infiltration, proliferation, and cytotoxicity both in vitro and in vivo, but blocking TGF-ß did not suppress the growth of EGFR-mutated tumors in vivo. Anti-TGF-ß antibody combined with anti-PD-1 antibody significantly inhibited the proliferation of recombinant EGFR-mutated tumors in C57BL/6N mice, which was superior to their monotherapy. Mechanistically, the combination of anti-TGF-ß and anti-PD-1 antibodies significantly increased the infiltration of CD8+ T cells and enhanced the anti-tumor function of CD8+ T cells. Moreover, we found that the expression of TGF-ß1 in EGFR-TKI resistant cell lines was significantly higher than that in parental cell lines. The combination of anti-TGF-ß and nivolumab significantly inhibited the proliferation of EGFR-TKI resistant tumors in humanized M-NSG mice and prolonged their survival. CONCLUSIONS: Our results reveal that TGF-ß expression is upregulated in NSCLC with EGFR mutations through the EGFR-ERK1/2-p90RSK signaling pathway. High TGF-ß expression inhibits the infiltration and anti-tumor function of CD8+ T cells, contributing to the "cold" TME of EGFR-mutated tumors. Blocking TGF-ß can reshape the TME and enhance the therapeutic efficacy of anti-PD-1 in EGFR-mutated tumors, which provides a potential combination immunotherapy strategy for advanced NSCLC patients with EGFR mutations.

Dacomitinib overcomes acquired resistance to osimertinib in advanced NSCLC patients with EGFR L718Q mutation: A two-case report.

RATIONALE: Acquired resistance still inevitably occurs in patients treated with third-generation TKI osimertinib. Although the EGFR L718Q mutation has been reported as a scarce mechanism of osimertinib resistance, advanced therapeutic strategies are still in development. In this report, we included 2 cases of patients who acquired EGFR L858R/L718Q mutation after osimertinib and were overcome by dacomitinib. PATIENT CONCERNS: Case 1: A 77-year-old woman was diagnosed with stage IV lung adenocarcinoma. Case 2: A 64-year-old woman was diagnosed with stage IV lung adenocarcinoma. DIAGNOSES: Case 1: The patient was diagnosed with adenocarcinoma with EGFR L858R mutation. Since then, treatment with gefitinib was administrated, leading to a progression-free survival of 18 months. The treatment was switched to osimertinib based on the detection of EGFR T790M mutation, resulting in a progression-free survival of 24 months. Subsequently, EGFR L718Q mutation was detected. Case 2: The patient was diagnosed with adenocarcinoma with EGFR L858R mutation. Icotinib was used as the first-line treatment for 7 months. Osimertinib was applied as the second-line treatment for 13 months based on the EGFR T790M mutation. Subsequently, EGFR L718Q mutation was detected. INTERVENTIONS: Case 1: Dacomitinib was administered. Case 2: Dacomitinib was administered. OUTCOMES: Case 1:The progression-free survival was 8 months. Case 2: The progression-free survival was 3 months. LESSONS: Dacomitinib is a potential treatment option for NSCLC patients with EGFR L718Q mutation after resistance to Osimertinib. Further research is needed to validate the efficacy of Dacomitinib in this context.

A non-enhancing, T2 fluid-attenuated inversion recovery hyperintense, diffusion-restricting brainstem lesion in an EGFR tyrosine kinase inhibitor-treated non-small-cell lung cancer patient.

Leptomeningeal metastasis (LM) is a devastating complication of malignancy. Diagnosis relies on both contrast enhancement on imaging and malignant cells in cerebral spinal fluid cytology. Though early detection and prompt intervention improves survival, the detection of LM is limited by false negatives. A rare brainstem imaging finding uncovered specifically in EGFR mutation-positive lung cancer patients may represent an early sign of LM. This sign demonstrates high signal on T2 fluid-attenuated inversion recovery and diffusion-weighted imaging sequences, but paradoxically lacks correlative contrast enhancement. Here we report a case of a 72-year-old female EGFR-positive lung cancer patient who developed this lesion following treatment with two first-generation EGFR tyrosine kinase inhibitors then showed subsequent response to osimertinib, an irreversible third-generation EGFR tyrosine kinase inhibitor.

A non-enhancing, T2 FLAIR hyperintense, diffusion-restricting brainstem lesion in an EGFR-positive lung cancer patient may represent an early indicator of leptomeningeal metastases.

Pathogenic strategies of Pseudogymnoascus destructans during torpor and arousal of hibernating bats.

Millions of hibernating bats across North America have died from white-nose syndrome (WNS), an emerging disease caused by a psychrophilic (cold-loving) fungus, Pseudogymnoascus destructans, that invades their skin. Mechanisms of P. destructans invasion of bat epidermis remain obscure. Guided by our in vivo observations, we modeled hibernation with a newly generated little brown bat (Myotis lucifugus) keratinocyte cell line. We uncovered the stealth intracellular lifestyle of P. destructans, which inhibits apoptosis of keratinocytes and spreads through the cells by two epidermal growth factor receptor (EGFR)-dependent mechanisms: active penetration during torpor and induced endocytosis during arousal. Melanin of endocytosed P. destructans blocks endolysosomal maturation, facilitating P. destructans survival and germination after return to torpor. Blockade of EGFR aborts P. destructans entry into keratinocytes.

EGFR V834L and L858R Comutation Is Associated With Response to Osimertinib in Non-Small-Cell Lung Cancer.

Up-front osimertinib leads to clinical benefit in EGFR V834L and L858R comutated NSCLC.

Exploring chromone-2-carboxamide derivatives for triple-negative breast cancer targeting EGFR, FGFR3, and VEGF pathways: Design, synthesis, and preclinical insights.

Chromone-based compounds have established cytotoxic, antiproliferative, antimetastatic, and antiangiogenic effects on various cancer cell types via modulating different molecular targets. Herein, 17 novel chromone-2-carboxamide derivatives were synthesized and evaluated for their in vitro anticancer activity against 15 human cancer cell lines. Among the tested cell lines, MDA-MB-231, the triple-negative breast cancer cell line, was found to be the most sensitive, where the N-(2-furylmethylene) (15) and the α-methylated N-benzyl (17) derivatives demonstrated the highest growth inhibition with GI50 values of 14.8 and 17.1 µM, respectively. In vitro mechanistic studies confirmed the significant roles of compounds 15 and 17 in the induction of apoptosis and suppression of EGFR, FGFR3, and VEGF protein levels in MDA-MB-231 cancer cells. Moreover, compound 15 exerted cell cycle arrest at both the G0-G1 and G2-M phases. The in vivo efficacy of compound 15 as an antitumor agent was further investigated in female mice bearing Solid Ehrlich Carcinoma. Notably, administration of compound 15 resulted in a marked decrease in both tumor weight and volume, accompanied by improvements in biochemical, hematological, histological, and immunohistochemical parameters that verified the repression of both angiogenesis and inflammation as additional Anticancer mechanisms. Moreover, the binding interactions of compounds 15 and 17 within the binding sites of all three target receptors (EGFR, FGFR3, and VEGF) were clearly illustrated using molecular docking.

An epidermal growth factor receptor-targeting immunotoxin based on IgG shows potent antitumor activity against head and neck cancer.

The epidermal growth factor receptor (EGFR) is an important target for cancer therapies. Many head and neck cancer (HNC) cells have been reported to overexpress EGFR; therefore, anti-EGFR therapies have been attempted in patients with HNC. However, its clinical efficacy is limited owing to the development of drug resistance. In this study, we developed an EGFR-targeting immunotoxin consisting of a clinically proven anti-EGFR IgG (cetuximab; CTX) and a toxin fragment (LR-LO10) derived from Pseudomonas exotoxin A (PE) using a novel site-specific conjugation technology (peptide-directed photo-crosslinking reaction), as an alternative option. The immunotoxin (CTX-LR-LO10) showed specific binding to EGFR and properties of a typical IgG, such as stability, interactions with receptors of immune cells, and pharmacokinetics, and inhibited protein synthesis via modification of elongation factor-2. Treatment of EGFR-positive HNC cells with the immunotoxin resulted in apoptotic cell death and the inhibition of cell migration and invasion. The efficacy of CTX-LR-LO10 was evaluated in xenograft mouse models, and the immunotoxin exhibited much stronger tumor suppression than CTX or LR-LO10. Transcriptome analyses revealed that the immunotoxins elicited immune responses and altered the expression of genes related to its mechanisms of action. These results support the notion that CTX-LR-LO10 may serve as a new therapeutic agent targeting EGFR-positive cancers.

Silencing of lncRNA LOC105376794 promotes migration, invasion, and Gefitinib resistance of lung adenocarcinoma cells with EGFR 19Del mutation by ATF4/CHOP axis and ERK phosphorylation.

Epidermal growth factor receptor (EGFR) gene exon 19 in-frame deletion (19del) and exon 21 L858R point mutation (21L858R mutation) are prevalent mutations in lung adenocarcinoma. Lung adenocarcinoma patients with 19del presented with a better prognosis than the 21L858R mutation under the same epidermal growth factor receptor tyrosine kinase inhibitor treatment. Our study aimed to uncover the expression of long non-coding RNA LOC105376794 between 19del and 21L858R mutation, and explore the mechanism that regulates cells' biological behavior and gefitinib sensitivity in lung adenocarcinoma cells with 19del. Transcriptome sequencing was conducted to identify differentially expressed lncRNAs between EGFR 19del and 21L858R mutation in serum through the DNBSEQ Platform. Protein-protein interaction network and Kyoto Encyclopedia of Genes and Genomes pathway were conducted to analyze the relationship between lncRNAs and mRNAs through STRING and Dr. TOM. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to measure the expression of lncRNA LOC105376794 in serum and cells. Loss-of-function experiments were used to validate the biological function and gefitinib sensitivity of LOC105376794 in lung adenocarcinoma cells. Protein levels were detected by western blotting. Through transcriptome resequencing and RT-qPCR, we found the expression levels of LOC105376794 in serum were increased in the 19del group compared with the 21L858R mutation group. Inhibition of LOC105376794 promoted proliferation, migration and invasion, and reduced apoptosis of HCC827 and PC-9 cells. The low expression of LOC105376794 reduced gefitinib sensitivity in PC-9 cells. Mechanistically, we found that the knockdown of LOC105376794 suppressed activating transcription factor 4 (ATF4)/C/EBP homologous protein (CHOP) signaling pathway and facilitated the expression of extracellular signal-regulated kinase 1/2 (ERK) phosphorylation. LOC105376794 altered cell biological behavior and gefitinib sensitivity of lung adenocarcinoma cells with 19del through the ATF4/CHOP signaling pathway and the expression of ERK phosphorylation. The results further illustrated the fact that lung adenocarcinoma patients with 19del presented with a more favorable clinical outcome and provided a theoretical basis for treatment strategy for lung adenocarcinoma patients with 19del.

Intestinal organoids to model Salmonella infection and its impact on progenitors.

In order to survive and replicate, Salmonella has evolved mechanisms to gain access to intestinal epithelial cells of the crypt. However, the impact of Salmonella Typhimurium on stem cells and progenitors, which are responsible for the ability of the intestinal epithelium to renew and protect itself, remains unclear. Given that intestinal organoids growth is sustained by stem cells and progenitors activity, we have used this model to document the effects of Salmonella Typhimurium infection on epithelial proliferation and differentiation, and compared it to an in vivo model of Salmonella infection in mice. Among gut segments, the caecum was preferentially targeted by Salmonella. Analysis of infected crypts and organoids demonstrated increased length and size, respectively. mRNA transcription profiles of infected crypts and organoids pointed to upregulated EGFR-dependent signals, associated with a decrease in secretory cell lineage differentiation. To conclude, we show that organoids are suited to mimic the impact of Salmonella on stem cells and progenitors cells, carrying a great potential to drastically reduce the use of animals for scientific studies on that topic. In both models, the EGFR pathway, crucial to stem cells and progenitors proliferation and differentiation, is dysregulated by Salmonella, suggesting that repeated infections might have consequences on crypt integrity and further oncogenesis.

Insights into treatment-specific prognostic somatic mutations in NSCLC from the AACR NSCLC GENIE BPC cohort analysis.

BACKGROUND: Treatment of non-small lung cancer (NSCLC) has evolved in recent years, benefiting from advances in immunotherapy and targeted therapy. However, limited biomarkers exist to assist clinicians and patients in selecting the most effective, personalized treatment strategies. Targeted next-generation sequencing-based genomic profiling has become routine in cancer treatment and generated crucial clinicogenomic data over the last decade. This has made the development of mutational biomarkers for drug response possible. METHODS: To investigate the association between a patient's responses to a specific somatic mutation treatment, we analyzed the NSCLC GENIE BPC cohort, which includes 2,004 tumor samples from 1,846 patients. RESULTS: We identified somatic mutation signatures associated with response to immunotherapy and chemotherapy, including carboplatin-, cisplatin-, pemetrexed- or docetaxel-based chemotherapy. The prediction power of the chemotherapy-associated signature was significantly affected by epidermal growth factor receptor (EGFR) mutation status. Therefore, we developed an EGFR wild-type-specific mutation signature for chemotherapy selection. CONCLUSION: Our treatment-specific gene signatures will assist clinicians and patients in selecting from multiple treatment options.

Anticancer activity of Araguspongine C via inducing apoptosis, and inhibition of oxidative stress, inflammation, and EGFR-TK in human lung cancer cells: An in vitro and in vivo study.

The advanced non-small cell lung cancer (NSCLC) that harbors epidermal growth factor receptor (EGFR) mutations has put a selective pressure on the discovery and development of newer EGFR inhibitors. Therefore, the present study intends to explore the pharmacological effect of Araguspongine C (Aragus-C) as anticancer agent against lung cancer. The effect of Aragus-C was evaluated on the viability of the A549 and H1975 cells. Further biochemical assays were performed to elaborate the effect of Aragus-C, on the apoptosis, cell-cycle analysis, and mitochondrial membrane potential in A549 cells. Western blot analysis was also conducted to determine the expression of EGFR in A549 cells. Tumor xenograft mice model from A549 cells was established to further elaborate the pharmacological activity of Aragus-C. Results suggest that Aragus C showed significant inhibitory activity against A549 cells as compared to H1975 cells. It has been found that Aragus-C causes the induction of apoptosis and promotes cell-cycle arrest at the G2/M phase of A549 cells. It also showed a reduction in the overexpression of EGFR in A549 cells. In tumor xenograft mice model, it showed a significant reduction of tumor volume in a dose-dependent manner, with maximum inhibitory activity was reported by the 8 mg/kg treated group. It also showed significant anti-inflammatory and antioxidant activity by reducing the level of TNF-α, IL-1ß, IL-6, and MDA, with a simultaneous increase of superoxide dismutase and glutathione peroxidase. We have demonstrated the potent anti-lung cancer activity of Aragus-C, and it may be considered as a potential therapeutic choice for NSCLC treatment.

Dual targeting non-overlapping epitopes in HER2 domain IV substantially enhanced HER2/HER2 homodimers and HER2/EGFR heterodimers internalization leading to potent antitumor activity in HER2-positive human gastric cancer.

BACKGROUND: Trastuzumab and pertuzumab combination has been approved for the treatment of patients with HER2-positive metastatic breast cancer. However, trastuzumab and pertuzumab combination did not show improvement in overall survival in patients with HER2-positive metastatic gastric cancer. METHODS: We developed a new HER2-targeted monoclonal antibody, HLX22, targeting HER2 subdomain IV as trastuzumab but with non-overlapping epitopes. We examined the antitumor effects of this novel HER2-antibody in gastric cell lines and cell line-derived xenograft (CDX) and patient-derived xenograft (PDX) models. RESULTS: HLX22 in combination with HLX02 (trastuzumab biosimilar) induced enhancement of HER2/HER2 homodimers and HER2/EGFR heterodimers internalization, which ultimately led to the reduction in signal transductions involving STAT3, P70 S6, and AKT; gene expressions of FGF-FGFR-PI3K-MTOR, EGF-EGFR-RAS, TGF-ß-SMAD, PLCG and cell cycle progression related pathways that favor tumor development, proliferation, progression, migration and survival in gastric cancer cell line NCI-N87 were also reduced. These differing but complementary actions contributed to the synergistic antitumor efficacy of the HLX22 and HLX02 combination in gastric cancer cell lines, CDX and PDX. In addition, HLX22 in combination with HLX02 demonstrated stronger antitumor efficacy than HLX02 and HLX11 (a potential pertuzumab biosimilar) combination treatment both in vitro and in vivo. CONCLUSIONS: These results suggested that the application of non-competing antibodies HLX22 and HLX02 targeting HER2 subdomain IV together may be of substantial benefit to gastric cancer patients who currently respond suboptimal to trastuzumab therapy.

LRIG1 controls proliferation of adult neural stem cells by facilitating TGFß and BMP signalling pathways.

Adult Neural Stem Cells (aNSCs) in the ventricular-subventricular zone (V-SVZ) are largely quiescent. Here, we characterize the mechanism underlying the functional role of a cell-signalling inhibitory protein, LRIG1, in the control of aNSCs proliferation. Using Lrig1 knockout models, we show that Lrig1 ablation results in increased aNSCs proliferation with no change in neuronal progeny and that this hyperproliferation likely does not result solely from activation of the epidermal growth factor receptor (EGFR). Loss of LRIG1, however, also leads to impaired activation of transforming growth factor beta (TGFß) and bone morphogenic protein (BMP) signalling. Biochemically, we show that LRIG1 binds TGFß/BMP receptors and the TGFß1 ligand. Finally, we show that the consequences of these interactions are to facilitate SMAD phosphorylation. Collectively, these data suggest that unlike in embryonic NSCs where EGFR may be the primary mechanism of action, in aNSCs, LRIG1 and TGFß pathways function together to fulfill their inhibitory roles.

Therapeutic potential of the secreted Kazal-type serine protease inhibitor SPINK4 in colitis.

Mucus injury associated with goblet cell (GC) depletion constitutes an early event in inflammatory bowel disease (IBD). Using single-cell sequencing to detect critical events in mucus dysfunction, we discover that the Kazal-type serine protease inhibitor SPINK4 is dynamically regulated in colitic intestine in parallel with disease activities. Under chemically induced colitic conditions, the grim status in Spink4-conditional knockout mice is successfully rescued by recombinant murine SPINK4. Notably, its therapeutic potential is synergistic with existing TNF-α inhibitor infliximab in colitis treatment. Mechanistically, SPINK4 promotes GC differentiation using a Kazal-like motif to modulate EGFR-Wnt/ß-catenin and -Hippo pathways. Microbiota-derived diacylated lipoprotein Pam2CSK4 triggers SPINK4 production. We also show that monitoring SPINK4 in circulation is a reliable noninvasive technique to distinguish IBD patients from healthy controls and assess disease activity. Thus, SPINK4 serves as a serologic biomarker of IBD and has therapeutic potential for colitis via intrinsic EGFR activation in intestinal homeostasis.

eHSP90α in front-line therapy in EGFR exon 19 deletion and 21 Leu858Arg mutations in advanced lung adenocarcinoma.

PURPOSE: Extracellular heat shock protein 90 AA1(eHSP90α) is intricately linked to tumor progression and prognosis. This study aimed to investigate the difference in the value of eHSP90α in post-treatment response assessment and prognosis prediction between exon 19 deletion(19DEL) and exon 21 Leu858Arg(L858R) mutation types in lung adenocarcinoma(LUAD). METHODS: We analyzed the relationship between the expression of eHSP90α and clinicopathological features in 89 patients with L858R mutation and 196 patients with 19DEL mutation in LUAD. The Kaplan-Meier survival curve was used to determine their respective cut-off values and analyze the relationship between eHSP90α expression and the survival time of the two mutation types. The area under the curve (AUC) was used to evaluate the diagnostic performance of biomarkers. Then, the prognostic model was developed using the univariate-Cox multivariate-Cox and LASSO-multivariate logistic methods. RESULTS: In LUAD patients, eHSP90α was positively correlated with carcinoembryonic antigen(CEA), carbohydrate antigen 125(CA125), and carbohydrate antigen 153(CA153). The truncated values of eHSP90α in L858R and 19DEL patients were 44.5 ng/mL and 40.8 ng/mL, respectively. Among L858R patients, eHSP90α had the best diagnostic performance (AUC = 0.765), and higher eHSP90α and T helper cells(Th cells) expression were significantly related to shorter overall survival(OS) and worse treatment response. Also, high eHSP90a expression and short progression-free survival(PFS) were significantly correlated. Among 19DEL patients, CEA had the best diagnostic efficacy (AUC = 0.734), and CEA and Th cells were independent prognostic factors that predicted shorter OS. Furthermore, high CA125 was significantly associated with short PFS and poor curative effect. CONCLUSIONS: eHSP90α has a better prognostic value in LUAD L858R patients than 19DEL, which provides a new idea for clinical diagnosis and treatment.

Submandibular Gland Pathogenesis Following SARS-CoV-2 Infection and Implications for Xerostomia.

Although SARS-CoV-2 induces mucin hypersecretion in the respiratory tract, hyposalivation/xerostomia has been reported by COVID-19 patients. We evaluate the submandibular gland (SMGs) pathogenesis in SARS-CoV-2-infected K18-hACE2 mice, focusing on the impact of infection on the mucin production and structural integrity of acini, ductal system, myoepithelial cells (MECs) and telocytes. The spike protein, the nucleocapsid protein, hACE2, actin, EGF, TNF-α and IL-1ß were detected by immunofluorescence, and the Egfr and Muc5b expression was evaluated. In the infected animals, significant acinar hypertrophy was observed in contrast to ductal atrophy. Nucleocapsid proteins and/or viral particles were detected in the SMG cells, mainly in the nuclear membrane-derived vesicles, confirming the nuclear role in the viral formation. The acinar cells showed intense TNF-α and IL-1ß immunoexpression, and the EGF-EGFR signaling increased, together with Muc5b upregulation. This finding explains mucin hypersecretion and acinar hypertrophy, which compress the ducts. Dying MECs and actin reduction were also observed, indicating failure of contraction and acinar support, favoring acinar hypertrophy. Viral assembly was found in the dying telocytes, pointing to these intercommunicating cells as viral transmitters in SMGs. Therefore, EGF-EGFR-induced mucin hypersecretion was triggered by SARS-CoV-2 in acinar cells, likely mediated by cytokines. The damage to telocytes and MECs may have favored the acinar hypertrophy, leading to ductal obstruction, explaining xerostomia in COVID-19 patients. Thus, acinar cells, telocytes and MECs may be viral targets, which favor replication and cell-to-cell viral transmission in the SMG, corroborating the high viral load in saliva of infected individuals.

Epidermal Growth Factor Receptor Targeting in Colorectal Carcinoma: Antibodies and Patient-Derived Organoids as a Smart Model to Study Therapy Resistance.

Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide. Therefore, the need for new therapeutic strategies is still a challenge. Surgery and chemotherapy represent the first-line interventions; nevertheless, the prognosis for metastatic CRC (mCRC) patients remains unacceptable. An important step towards targeted therapy came from the inhibition of the epidermal growth factor receptor (EGFR) pathway, by the anti-EGFR antibody, Cetuximab, or by specific tyrosine kinase inhibitors (TKI). Cetuximab, a mouse-human chimeric monoclonal antibody (mAb), binds to the extracellular domain of EGFR thus impairing EGFR-mediated signaling and reducing cell proliferation. TKI can affect the EGFR biochemical pathway at different steps along the signaling cascade. Apart from Cetuximab, other anti-EGFR mAbs have been developed, such as Panitumumab. Both antibodies have been approved for the treatment of KRAS-NRAS wild type mCRC, alone or in combination with chemotherapy. These antibodies display strong differences in activating the host immune system against CRC, due to their different immunoglobulin isotypes. Although anti-EGFR antibodies are efficient, drug resistance occurs with high frequency. Resistant tumor cell populations can either already be present before therapy or develop later by biochemical adaptations or new genomic mutations in the EGFR pathway. Numerous efforts have been made to improve the efficacy of the anti-EGFR mAbs or to find new agents that are able to block downstream EGFR signaling cascade molecules. Indeed, we examined the importance of analyzing the anti-EGFR antibody-drug conjugates (ADC) developed to overcome resistance and/or stimulate the tumor host's immunity against CRC growth. Also, patient-derived CRC organoid cultures represent a useful and feasible in vitro model to study tumor behavior and therapy response. Organoids can reflect tumor genetic heterogeneity found in the tissue of origin, representing a unique tool for personalized medicine. Thus, CRC-derived organoid cultures are a smart model for studying the tumor microenvironment and for the preclinical assay of anti-EGFR drugs.

Impact of Interleukin-6 Activation and Arthritis on Epidermal Growth Factor Receptor (EGFR) Activation in Sensory Neurons and the Spinal Cord.

In tumor cells, interleukin-6 (IL-6) signaling can lead to activation of the epidermal growth factor receptor (EGFR), which prolongs Stat3 activation. In the present experiments, we tested the hypothesis that IL-6 signaling activates EGFR signaling in peripheral and spinal nociception and examined whether EGFR localization and activation coincide with pain-related behaviors in arthritis. In vivo in anesthetized rats, spinal application of the EGFR receptor blocker gefitinib reduced the responses of spinal cord neurons to noxious joint stimulation, but only after spinal pretreatment with IL-6 and soluble IL-6 receptor. Using Western blots, we found that IL-6-induced Stat3 activation was reduced by gefitinib in microglial cells of the BV2 cell line, but not in cultured DRG neurons. Immunohistochemistry showed EGFR localization in most DRG neurons from normal rats, but significant downregulation in the acute and most painful arthritis phase. In the spinal cord of mice, EGFR was highly activated mainly in the chronic phase of inflammation, with localization in neurons. These data suggest that spinal IL-6 signaling may activate spinal EGFR signaling. Downregulation of EGFR in DRG neurons in acute arthritis may limit nociception, but pronounced delayed activation of EGFR in the spinal cord may be involved in chronic inflammatory pain.

Clinical features associated with NeoRAS wild-type metastatic colorectal cancer A SCRUM-Japan GOZILA substudy.

"NeoRAS WT" refers to the loss of RAS mutations (MTs) following first-line treatment in metastatic colorectal cancer (mCRC). We evaluate the incidence and clinicopathological characteristics of NeoRAS WT mCRC using next-generation sequencing of plasma circulating tumor DNA. Patients with mCRC enrolled in the GOZILA study initially diagnosed with tissue RAS MT mCRC and received subsequent systemic therapy are eligible. NeoRAS WT is defined as the absence of detectable RAS MT in plasma and assessed in all eligible patients (Group A) and in a subgroup with at least one somatic alteration detected in plasma (Group B). Overall, 478 patients are included. NeoRAS WT prevalence is 19.0% (91/478) in Group A and 9.8% (42/429) in Group B. Absence of liver or lymph node metastasis and tissue RAS MTs other than KRAS exon 2 MTs are significantly associated with NeoRAS WT emergence. Overall, 1/6 and 2/6 patients with NeoRAS WT treated with anti-EGFR monoclonal antibodies (mAbs) show partial response and stable disease for ≥6 months, respectively. NeoRAS WT mCRC is observed at a meaningful prevalence, and anti-EGFR mAb-based therapy may be effective.