Cutaneous sarcoid-like drug reaction caused by an anaplastic lymphoma kinase inhibitor

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.

Cutaneous toxicity of FDA-approved small-molecule kinase inhibitors

INTRODUCTION

By 1 January 2021, the FDA has approved a total of 62 small-molecule kinase inhibitors (SMKIs). The increasing clinical use of small-molecule kinase inhibitors has led to some side effects, the most common of which is cutaneous toxicity, as reflected by approximately 90% (57 of 62) of the FDA-approved SMKIs have reported treatment-related cutaneous toxicities. Since these cutaneous toxicities may have a crucial influence on the emotional, physical and psychosocial health of the patients, it is of great importance for doctors, patients, oncologists and interrelated researchers to be aware of the cutaneous side effects of these drugs in order to make the diagnosis accurate and the treatment appropriate.

AREAS COVERED

This review aims to summarize the potential cutaneous toxicities and the frequency of occurrence of FDA-approved 62 SMKIs, and provide a succinct overview of the potential mechanisms of certain cutaneous toxicities. The literature review was performed based on PubMed database and FDA official website.

EXPERT OPINION

It is significant to determine the risk factors for SMKI-induced cutaneous toxicity. The mechanisms underlying SMKI-induced cutaneous toxicities remain unclear at present. Future research should focus on the mechanisms of SMKI-induced cutaneous toxicities to find out mechanistically driven therapies.