rhEGF Treatment Improves EGFR Inhibitor-Induced Skin Barrier and Immune Defects

Improvement of classical therapy in EGFR inhibitors-induced cutaneous adverse reaction by microneedle delivery and Astragalus polysaccharide

EGFR (epidermal growth factor receptor) inhibitors, as the first-line drugs of targeted therapy, often cause additional distress for patients due to the induced cutaneous adverse reactions (EICAR), while classical therapies represented by topical minocycline and epidermal growth factor have limitations especially for exacerbating immune imbalance. Here, we used Astragalus polysaccharide (APS), which has modulatory effects on both the epidermis and the immune system, as an adjuvant drug to reduce EICAR and achieve immune balance. APS, combined with minocycline or epidermal growth factor, was delivered by dissolvable microneedles (MN), a novel drug delivery method that penetrates the stratum corneum to deliver the drug directly into the skin tissue. The results demonstrated that this therapy with the developed MN system not only restored local epidermal conditions, but also reestablished the balance of immune cells. Significantly, the addition of APS also promoted the alleviation of EICAR in non-treated areas, suggesting that local administration can result in systemic effects. The application of APS and the MN delivery system can provide new strategy for clinical treatment of EICAR and potential solutions for other skin diseases.

Brigatinib can inhibit proliferation and induce apoptosis of human immortalized keratinocyte cells

Background

Brigatinib is approved in multiple countries for the treatment of patients with anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC). Despite its superior efficacy, the dermal toxicities caused by brigatinib cannot be overlooked. However, its underlying mechanism remains unknown.

Methods

The effects of brigatinib on the proliferation ability of human immortalized keratinocyte (HaCaT) cells were evaluated using Cell Counting Kit-8 (CCK-8) proliferation, colony formation, and 5-ethynyl-2'-deoxyuridine (EdU) incorporation assays. The effects of brigatinib on apoptosis were detected using Annexin FITC/PI and Acridine Orange (AO) staining assays. Cell cycle was assessed with flow cytometry. An analysis of transcriptome by RNA sequencing procedures (RNA-seq) was performed to reveal the key regulatory genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to find out the biological function and related signal pathways. The expressions of amphiregulin, epiregulin and transforming growth factor alpha (TGFA) and the protein levels of Phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) and Cleaved-Caspase three were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot assay.

Results

Brigatinib inhibits cell proliferation with an IC50 value of 2.9 μmol/L and significantly increases apoptosis rates. Transcriptome sequencing (RNA-seq) indicates that brigatinib could significantly downregulate the expression of amphiregulin, epiregulin and TGFA. In addition, we demonstrated that brigatinib reduced the protein expression of amphiregulin, epiregulin, TGFA, PI3K, AKT and phosphorylated AKT (p-AKT).

Conclusion

This study confirms the inhibition of HaCaT cells growth and progression by brigatinib and highlights the potential value of the PI3K/AKT pathway as a therapeutic target for brigatinib-induced dermal toxicities.

Epidermal growth factor dampens pro-inflammatory gene expression induced by interferon-gamma in global transcriptome analysis of keratinocytes

BACKGROUND

Epidermal growth factor receptor inhibitors (EGFRIs) are used to treat certain cancers but frequently cause cutaneous inflammation that can hinder treatment. This is due in part to the effects of EGFRIs on pro-inflammatory signaling by interferon-γ (IFN-γ). However, the impact of EGFR ligands (i.e. EGF) on interferon signaling is unclear. The purpose of this study was to investigate the impact of EGF on IFN-γ transcriptional responses on a genome-wide scale in keratinocytes.

METHODS

RNA-seq was performed in human keratinocyte (HaCaT) cells treated with IFN-γ, EGF, both, or neither (control). Differentially expressed genes in each treatment group, relative to control, were identified using DESeq2 with a false discovery rate (FDR) threshold of 0.01. Associated biologic processes and gene pathways were examined in gene-set enrichment analyses. Correlations between gene expression were investigated in vivo using RNA-seq data from biopsies of psoriatic and matched normal skin, which were collected from 116 individuals with psoriasis enrolled in the AMAGINE randomized clinical trials.

RESULTS

Of the 2,792 differentially expressed genes following IFN-γ treatment, 2,083 (75%) were no longer differentially expressed when EGF was added. IFN-γ-induced genes with significantly lower expression in the presence of EGF included CXCL10, IL-6, IL-1 A, HLA-DMA, and GBP5 (activator of the NLRP3 inflammasome); the top enriched biologic processes and pathways were related to MHC-class II antigen presentation (GO:0019886) and cytokine signaling (KEGG:04060). Consistent with our in vitro findings, the expression of CXCL10 and GBP5, as well as the combined expression z-scores of genes in the enriched MHC-class II and cytokine signaling pathways, were significantly lower in skin biopsies with higher EGF expression compared to those with lower EGF expression among individuals with psoriasis.

CONCLUSIONS

Our findings suggest that the pro-inflammatory IFN-γ-induced transcriptome may be globally attenuated by EGF in keratinocytes, supporting an immunomodulatory role of EGF in the skin. These studies provide insights for the non-canonical immunomodulatory role of EGF signaling and why blocking EGFR signaling (e.g., with EGFRIs) can cause cutaneous inflammation.

Immunoexpression of metallothionein, Ki‐67 and PCNA in dermoid and epidermoid cysts of the oral cavity

Objective

To assess the immunoexpression of metallothionein and cell proliferation markers (Ki‐67 and PCNA) in a series of cases comprising four dermoid cysts and six epidermoid cysts of the oral cavity.

Materials and Methods

The percentages of nuclear and/or cytoplasmic staining in the basal and suprabasal layers of the cysts' epithelial lining were assessed.

Results

This study included six males and four females, with a mean age of 33.1 years. The floor of the mouth was affected in 40% of the cases. The expression of metallothionein, Ki‐67, and PCNA was observed in all cases examined. For both lesions, the basal layer exhibited higher cytoplasmic and nuclear/cytoplasmic expression of metallothionein. Dermoid cysts exhibited higher expression of Ki‐67 and PCNA compared to epidermoid cysts in both basal and suprabasal layers, with a more pronounced expression in the suprabasal layers.

Conclusions

Our results indicate that metallothionein is present in the epithelial lining of both dermoid and epidermoid cysts of the oral cavity. The cell proliferation indices observed in both conditions reflect their benign nature and slow growth.

Assessing Barrier Function in Psoriasis and Cornification Models of Artificial Skin Using Non-Invasive Impedance Spectroscopy

Reconstructed epidermal equivalents (REEs) consist of two distinct cell layers - the stratum corneum (SC) and the keratinocyte layer (KL). The interplay of these layers is particularly crucial in pruritic inflammatory disorders, like psoriasis, where a defective SC barrier is associated with immune dysregulation. However, independent evaluation of the skin barrier function of the SC and KL in REEs is highly challenging because of the lack of quantitative methodologies that do not disrupt the counter layer. Here, a non-invasive impedance spectroscopy technique is introduced for dissecting the distinct contributions of the SC and KL to overall skin barrier function without disrupting the structure. These findings, inferred from the impedance spectra, highlight the individual barrier resistances and maturation levels of each layer. Using an equivalent circuit model, a correlation between impedance parameters and specific skin layers, offering insights beyond traditional impedance methods that address full-thickness skin only is established. This approach successfully detects subtle changes, such as increased paracellular permeability due to mild irritants and the characterization of an immature SC in psoriatic models. This research has significant implications, paving the way for detailed mechanistic investigations and fostering the development of therapies for skin irritation and inflammatory disorders.

Mechanism of action of adapalene for treating EGFR-TKI-induced skin disorder

BACKGROUND

Skin disorders are the most common side effect associated with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy. It is important to manage skin lesions. Adapalene has been used to treat skin lesions caused by EGFR-TKIs in some cases. The aim of this study was to investigate the functional mechanism of adapalene in erlotinib-induced skin disorder.

METHODS

To analyze the effect of adapalene on skin rash, afatinib and adapalene were administered to mice. The relationship between the concentration of adapalene and skin disorders was also examined by analyzing AQP3 expression. A skin lesion model was experimentally established in human skin keratinocytes (HaCaT) by using erlotinib with TNF-α and IL-1β. We used qRT-PCR to analyze chemokine-induced inflammation and western blotting to analyze the effects of adapalene on the NF-κB signaling pathway. Antimicrobial peptides and adhesion factors were also examined using qRT-PCR.

RESULTS

Mice administered 0.01% adapalene had less skin inflammation than mice treated with afatinib alone. The expression level of AQP3 decreased in an adapalene concentration-dependent manner. The mRNA levels of proinflammatory cytokines such as CCL2 and CCL27 in HaCaT cells were significantly reduced by adapalene. The expression of an antimicrobial peptide, hBD3, was upregulated after adapalene treatment. Adhesion factors, such as E-cadherin, were significantly downregulated by EGFR-TKI and significantly upregulated by adapalene treatment. Western blot analysis suggested that erlotinib-induced phosphorylation of p65 was decreased by adapalene.

CONCLUSION

We suggest that adapalene may be a possible treatment option for skin disorders induced by EGFR-TKIs.

The use of epidermal growth factor in dermatological practice

Epidermal growth factor (EGF) is a growth factor that plays a pivotal role in wound healing and maintaining tissue homeostasis by regulating cell survival, proliferation, migration, and differentiation. Exogenous administration of bioidentical human recombinant epidermal growth factor (rhEGF) has been known to promote skin wound healing, although rhEGF is increasingly being used in drug delivery systems and nanotechnology. However, despite considerable attention being focused on the potential clinical applications of rhEGF in several dermatological conditions beyond wound healing, the number of studies still remains relatively low. Herein, we conducted a literature search of PubMed/Medline and Google Scholar databases to retrieve published literature related to rhEGF and summarised the effects of rhEGF in the treatment of various wound types, radiotherapy or chemotherapy-related skin reactions, atopic dermatitis, skin aging, and post-inflammatory hyperpigmentation.

EGFR Activation Impairs Antiviral Activity of Interferon Signaling in Brain Microvascular Endothelial Cells During Japanese Encephalitis Virus Infection

The establishment of Japanese encephalitis virus (JEV) infection in brain microvascular endothelial cells (BMECs) is thought to be a critical step to induce viral encephalitis with compromised blood–brain barrier (BBB), and the mechanisms involved in this process are not completely understood. In this study, we found that epidermal growth factor receptor (EGFR) is related to JEV escape from interferon-related host innate immunity based on a STRING analysis of JEV-infected primary human brain microvascular endothelial cells (hBMECs) and mouse brain. At the early phase of the infection processes, JEV induced the phosphorylation of EGFR. In JEV-infected hBMECs, a rapid internalization of EGFR that co-localizes with the endosomal marker EEA1 occurred. Using specific inhibitors to block EGFR, reduced production of viral particles was observed. Similar results were also found in an EGFR-KO hBMEC cell line. Even though the process of viral infection in attachment and entry was not noticeably influenced, the induction of IFNs in EGFR-KO hBMECs was significantly increased, which may account for the decreased viral production. Further investigation demonstrated that EGFR downstream cascade ERK, but not STAT3, was involved in the antiviral effect of IFNs, and a lowered viral yield was observed by utilizing the specific inhibitor of ERK. Taken together, the results revealed that JEV induces EGFR activation, leading to a suppression of interferon signaling and promotion of viral replication, which could provide a potential target for future therapies for the JEV infection.

Mechanism of Lethal Skin Toxicities Induced by Epidermal Growth Factor Receptor Inhibitors and Related Treatment Strategies

Epidermal growth factor receptor (EGFR) inhibitors are widely used to treat various types of cancers such as non-small cell lung cancer, head and neck cancer, breast cancer, pancreatic cancer. Adverse reactions such as skin toxicity, interstitial lung disease, hepatotoxicity, ocular toxicity, hypomagnesemia, stomatitis, and diarrhea may occur during treatment. Because the EGFR signaling pathway is important for maintaining normal physiological skin function. Adverse skin reactions occurred in up to 90% of cancer patients treated with EGFR inhibitors, including common skin toxicities (such as papulopustular exanthemas, paronychia, hair changes) and rare fatal skin toxicities (e.g., Stevens–Johnson syndrome, toxic epidermal necrolysis, acute generalized exanthematous pustulosis). This has led to the dose reduction or discontinuation of EGFR inhibitors in the treatment of cancer. Recently, progress has been made about research on the skin toxicity of EGFR inhibitors. Here, we summarize the mechanism of skin toxicity caused by EGFR inhibitors, measures to prevent severe fatal skin toxicity, and provide reference for medical staff how to give care and treatment after adverse skin reactions.

Exploring the role of epidermal growth factor receptor variant III in meningeal tumors

Meningioma is the second most common type of intracranial brain tumor. Immunohistochemical techniques have shown prodigious results in the role of epidermal growth factor receptor variant III (EGFR vIII) in glioma and other cancers. However, the role of EGFR vIII in meningioma is still in question. This study attempt the confer searches for the position attained by EGFR vIII in progression and expression of meningioma. Immunohistochemistry technique showed that EGFR vIII is highly expressed in benign tumors as compared to the atypical meningioma with a highly significant p-value (p<0.05). Further analysis by flow cytometry results supported these findings thus presented high intensity of EGFR vIII in low grades of meningioma. The study revealed that the significant Ki 67 values, to predictor marker for survival and prognosis of the patients. Higher expression of EGFR vIII in low grades meningiomas as compared to high-grade tumors indicate towards its oncogenic properties. To our knowledge, limited studies reported in literature expressing the EGFR vIII in meningioma tumors. Hence, Opinions regarding the role that EGFR vIII in tumorigenesis and tumor progression are clearly conflicting and, therefore, it is crucial not only to find out its mechanism of action, but also to definitely identify its role in meningioma.

Immune function in X-linked retinoschisis subjects in an AAV8-RS1 phase I/IIa gene therapy trial

This study explored systemic immune changes in 11 subjects with X-linked retinoschisis (XLRS) in a phase I/IIa adeno-associated virus 8 (AAV8)-RS1 gene therapy trial (ClinicalTrials.gov: NCT02317887). Immune cell proportions and serum analytes were compared to 12 healthy male controls. At pre-dosing baseline the mean CD4/CD8 ratio of XLRS subjects was elevated. CD11c⁺ myeloid dendritic cells (DCs) and the serum epidermal growth factor (EGF) level were decreased, while CD123⁺ plasmacytoid DCs and serum interferon (IFN)-γ and tumor necrosis factor (TNF)-α were increased, indicating that the XLRS baseline immune status differs from that of controls. XLRS samples 14 days after AAV8-RS1 administration were compared with the XLRS baseline. Frequency of CD11b⁺CD11c⁺ DCc was decreased in 8 of 11 XLRS subjects across all vector doses (1e9-3e11 vector genomes [vg]/eye). CD8⁺human leukocyte antigen-DR isotype (HLA-DR)⁺ cytotoxic T cells and CD68⁺CD80⁺ macrophages were upregulated in 10 of 11 XLRS subjects, along with increased serum granzyme B in 8 of 11 XLRS subjects and elevated IFN-γ in 9 of 11 XLRS subjects. The six XLRS subjects with ocular inflammation after vector application gave a modestly positive correlation of inflammation score to their respective baseline CD4/CD8 ratios. This exploratory study indicates that XLRS subjects may exhibit a proinflammatory, baseline immune phenotype, and that intravitreal dosing with AAV8-RS1 leads to systemic immune activation with an increase of activated lymphocytes, macrophages, and proinflammatory cytokines.