Vandetanib inhibits cell growth in EGFR-expressing cutaneous squamous cell carcinoma

Revolutionizing non-melanoma skin cancer treatment: Receptor tyrosine kinase inhibitors take the stage

BACKGROUND

Innovative treatments for non-melanoma skin cancers (NMSCs) are required to enhance patient outcomes.

AIMS

This review examines the effectiveness and safety of receptor tyrosine kinase inhibitors (RTKIs).

METHODS

A comprehensive review was conducted on the treatment potential of several RTKIs, namely cetuximab, erlotinib, gefitinib, panitumumab, and lapatinib.

RESULTS

The findings indicate that these targeted therapies hold great promise for the treatment of NMSCs. However, it is crucial to consider relapse rates and possible adverse effects. Further research is needed to improve treatment strategies, identify patient groups that would benefit the most, and assess the long-term efficacy and safety, despite the favorable results reported in previous studies. Furthermore, it is crucial to investigate the potential benefits of integrating RTKIs with immunotherapy and other treatment modalities to enhance the overall efficacy of therapy for individuals with NMSC.

CONCLUSIONS

Targeted therapies for NMSCs may be possible with the use of RTKIs. The majority of studies focused on utilizing epidermal growth factor receptor inhibitors as the primary class of RTKIs for the treatment of NMSC. Other RTKIs were only employed in experimental investigations. Research indicates that RTKIs could potentially serve as a suitable alternative for elderly patients who are unable to undergo chemotherapy and radiotherapy.

miR-184 represses β-catenin and behaves as a skin tumor suppressor

miR-184-knockout mice display perturbed epidermal stem cell differentiation. However, the potential role of miR-184 in skin pathology is unclear. Here, we report that miR-184 controls epidermal stem cell dynamics and that miR-184 ablation enhances skin carcinogenesis in mice. In agreement, repression of miR-184 in human squamous cell carcinoma (SCC) enhances neoplastic hallmarks of human SCC cells in vitro and tumor development in vivo. Characterization of miR-184-regulatory network, suggests that miR-184 inhibits pro-oncogenic pathways, cell proliferation, and epithelial to mesenchymal transformation. Of note, depletion of miR-184 enhances the levels of β-catenin under homeostasis and following experimental skin carcinogenesis. Finally, the repression of β-catenin by miR-184, inhibits the neoplastic phenotype of SCC cells. Taken together, miR-184 behaves as an epidermal tumor suppressor, and may provide a potentially useful target for skin SCC therapy.

Targeted Inhibitors of EGFR: Structure, Biology, Biomarkers, and Clinical Applications

Members of the EGFR family of tyrosine kinase receptors are major regulators of cellular proliferation, differentiation, and survival. In humans, abnormal activation of EGFR is associated with the development and progression of many cancer types, which makes it an attractive target for molecular-guided therapy. Two classes of EGFR-targeted cancer therapeutics include monoclonal antibodies (mAbs), which bind to the extracellular domain of EGFR, and tyrosine kinase inhibitors (TKIs), which mostly target the intracellular part of EGFR and inhibit its activity in molecular signaling. While EGFR-specific mAbs and three generations of TKIs have demonstrated clinical efficacy in various settings, molecular evolution of tumors leads to apparent and sometimes inevitable resistance to current therapeutics, which highlights the need for deeper research in this field. Here, we tried to provide a comprehensive and systematic overview of the rationale, molecular mechanisms, and clinical significance of the current EGFR-targeting drugs, highlighting potential candidate molecules in development. We summarized the underlying mechanisms of resistance and available personalized predictive approaches that may lead to improved efficacy of EGFR-targeted therapies. We also discuss recent developments and the use of specific therapeutic strategies, such as multi-targeting agents and combination therapies, for overcoming cancer resistance to EGFR-specific drugs.

Targeting the EGFR signaling pathway in cancer therapy: What's new in 2023?

INTRODUCTION

Epidermal growth factor receptor (EGFR) is frequently amplified, overexpressed, and mutated in multiple cancers. In normal cell physiology, EGFR signaling controls cellular differentiation, proliferation, growth, and survival. During tumorigenesis, mutations in EGFR lead to increased kinase activity supporting survival, uncontrolled proliferation, and migratory functions of cancer cells. Molecular agents targeting the EGFR pathway have been discovered, and their efficacy has been demonstrated in clinical trials. To date, 14 EGFR-targeted agents have been approved for cancer treatments.

AREAS COVERED

This review describes the newly identified pathways in EGFR signaling, the evolution of novel EGFR-acquired and innate resistance mechanisms, mutations, and adverse side effects of EGFR signaling inhibitors. Subsequently, the latest EGFR/panEGFR inhibitors in preclinical and clinical studies have been summarized. Finally, the consequences of combining immune checkpoint inhibitors and EGFR inhibitors have also been discussed.

EXPERT OPINION

As new mutations are threatened against EGFR-tyrosine kinase inhibitors (TKIs), we suggest the development of new compounds targeting specific mutations without inducing new mutations. We discuss potential future research on developing EGFR-TKIs specific for exact allosteric sites to overcome acquired resistance and reduce adverse events. The rising trend of EGFR inhibitors in the pharma market and their economic impact on real-world clinical practice are discussed.

Pulmonary toxicity in driver gene positive non-small cell lung cancer therapy

Molecular targeted therapy significantly improved the therapeutic efficacy in non-small cell lung cancer (NSCLC) patients with driver gene mutations but also with new toxicity profiles. Although most patients treated with these drugs developed relatively controllable toxicity, significant pulmonary toxicity events, including interstitial lung disease, occurred in a small proportion of patients and can lead to discontinuation or even be life-threatening. Pulmonary toxicity associated with these anti-tumor drugs is a problem that cannot be ignored in clinical practice. The prompt diagnosis of drug-related lung injury and the consequent differential diagnosis with other forms of pulmonary disease are critical in the management of pulmonary toxicity. Current knowledge of the pathophysiology and management of pulmonary toxicity associated with these targeted drugs is limited, and participants should be able to identify and respond to the development of drug-induced pulmonary toxicity. This review offers information about the potential pathogenesis, risk factors and management for the development of these events based on the available literature. This review focused on pulmonary toxicities in driver gene-positive NSCLC therapy by describing the related adverse events to promote the awareness and management of this important toxicity related to antitumor-targeted therapy.

Bivalent EGFR-Targeting DARPin-MMAE Conjugates

Epidermal growth factor receptor (EGFR) is a validated tumor marker overexpressed in various cancers such as squamous cell carcinoma (SSC) of the head and neck and gliomas. We constructed protein-drug conjugates based on the anti-EGFR Designed Ankyrin Repeat Protein (DARPin) E01, and compared the bivalent DARPin dimer (DD1) and a DARPin-Fc (DFc) to the monomeric DARPin (DM) and the antibody derived scFv425-Fc (scFvFc) in cell culture and a mouse model. The modular conjugation system, which was successfully applied for the preparation of protein-drug and -dye conjugates, uses bio-orthogonal protein-aldehyde generation by the formylglycine-generating enzyme (FGE). The generated carbonyl moiety is addressed by a bifunctional linker with a pyrazolone for a tandem Knoevenagel reaction and an azide for strain-promoted azide-alkyne cycloaddition (SPAAC). The latter reaction with a PEGylated linker containing a dibenzocyclooctyne (DBCO) for SPAAC and monomethyl auristatin E (MMAE) as the toxin provided the stable conjugates DD1-MMAE (drug-antibody ratio, DAR = 2.0) and DFc-MMAE (DAR = 4.0) with sub-nanomolar cytotoxicity against the human squamous carcinoma derived A431 cells. In vivo imaging of Alexa Fluor 647-dye conjugates in A431-xenografted mice bearing subcutaneous tumors as the SCC model revealed unspecific binding of bivalent DARPins to the ubiquitously expressed EGFR. Tumor-targeting was verified 6 h post-injection solely for DD1 and scFvFc. The total of four administrations of 6.5 mg/kg DD1-MMAE or DFc-MMAE twice weekly did not cause any sequela in mice. MMAE conjugates showed no significant anti-tumor efficacy in vivo, but a trend towards increased necrotic areas (p = 0.2213) was observed for the DD1-MMAE (n = 5).

Oh, the Mutations You'll Acquire! A Systematic Overview of Cutaneous Squamous Cell Carcinoma

Nearly two million cases of cutaneous squamous cell carcinoma (cSCC) are diagnosed every year in the United States alone. cSCC is notable for both its prevalence and its propensity for invasion and metastasis. For many patients, surgery is curative. However, patients experiencing immunosuppression or recurrent, advanced, and metastatic disease still face limited therapeutic options and significant mortality. cSCC forms after decades of sun exposure and possesses the highest known mutation rate of all cancers. This mutational burden complicates efforts to identify the primary factors driving cSCC initiation and progression, which in turn hinders the development of targeted therapeutics. In this review, we summarize the mutations and alterations that have been observed in patients’ cSCC tumors, affecting signaling pathways, transcriptional regulators, and the microenvironment. We also highlight novel therapeutic opportunities in development and clinical trials.