Hepatotoxicity of FDA-approved small molecule kinase inhibitors

Underlying mechanisms and management strategies for regorafenib-induced toxicity in hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) accounts for 85% of liver cancer cases and is the third leading cause of cancer death. Regorafenib is a multi-target inhibitor that dramatically prolongs progression-free survival in HCC patients who have failed sorafenib therapy. However, one of the primary factors limiting regorafenib's clinical utilization is toxicity. Using Clinical Trials.gov and PubMed, we gathered clinical data on regorafenib and conducted a extensive analysis of the medication's adverse reactions and mechanisms. Next, we suggested suitable management techniques to improve regorafenib's effectiveness.

AREAS COVERED

We have reviewed the mechanisms by which regorafenib-induced toxicity occurs and general management strategies through clinical trials of regorafenib. Furthermore, by examining the literature on regorafenib and other tyrosine kinase inhibition, we summarized the mechanics of the onset of regorafenib toxicity and mechanism-based intervention strategies by reviewing the literature related to regorafenib and other tyrosine kinase inhibition.

EXPERT OPINION

One of the primary factors restricting regorafenib's clinical utilization and combination therapy is its toxicity reactions. To optimize regorafenib treatment regimens, it is especially important to further understand the specific toxicity mechanisms of regorafenib as a multi-kinase inhibitor.

Liver Pathology Related to Onco-Therapeutic Agents

Oncotherapeutic agents can cause a wide range of liver injuries from elevated liver functions tests to fulminant liver failure. In this review, we emphasize a newer generation of drugs including immune checkpoint inhibitors, protein kinase inhibitors, monoclonal antibodies, and hormonal therapy. A few conventional chemotherapy agents are also discussed.

Metabolic activation of tyrosine kinase inhibitors: recent advance and further clinical practice

At present, receptor tyrosine kinase signaling-related pathways have been successfully mediated to inhibit tumor proliferation and promote anti-angiogenesis effects for cancer therapy. Tyrosine kinase inhibitors (TKIs), a group of novel chemotherapeutic agents, have been applied to treat diverse malignant tumors effectively. However, the latent toxic and side effects of TKIs, such as hepatotoxicity and cardiotoxicity, limit their use in clinical practice. Metabolic activation has the potential to lead to toxic effects. Numerous TKIs have been demonstrated to be transformed into chemically reactive/potentially toxic metabolites following cytochrome P450-catalyzed activation, which causes severe adverse reactions, including hepatotoxicity, cardiotoxicity, skin toxicity, immune injury, mitochondria injury, and cytochrome P450 inactivation. However, the precise mechanisms of how these chemically reactive/potentially toxic species induce toxicity remain poorly understood. In addition, we present our viewpoints that regulating the production of reactive metabolites may decrease the toxicity of TKIs. Exploring this topic will improve understanding of metabolic activation and its underlying mechanisms, promoting the rational use of TKIs. This review summarizes the updated evidence concerning the reactive metabolites of TKIs and the associated toxicities. This paper provides novel insight into the safe use of TKIs and the prevention and treatment of multiple TKIs adverse effects in clinical practice.

Exploring Low-Toxicity Chemical Space with Deep Learning for Molecular Generation

Creating a wide range of new compounds that not only have ideal pharmacological properties but also easily pass long-term toxicity evaluation is still a challenging task in current drug discovery. In this study, we developed a conditional generative model by combining a semisupervised variational autoencoder (SSVAE) with an MGA toxicity predictor. Our aim is to generate molecules with low toxicity, good drug-like properties, and structural diversity. For multiobjective optimization, we have developed a method with hierarchical constraints on the toxicity space of small molecules to generate drug-like small molecules, which can also minimize the effect on the diversity of generated results. The evaluation results of the metrics indicate that the developed model has good effectiveness, novelty, and diversity. The generated molecules by this model are mainly distributed in low-toxicity regions, which suggests that our model can efficiently constrain the generation of toxic structures. In contrast to simply filtering toxic ones after generation, the low-toxicity molecular generative model can generate molecules with structural diversity. Our strategy can be used in target-based drug discovery to improve the quality of generated molecules with low-toxicity, drug-like, and highly active properties.

An Insight into the Novel Immunotherapy and Targeted Therapeutic Strategies for Hepatocellular Carcinoma and Cholangiocarcinoma

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) constitute highly malignant forms of primary liver cancers. Hepatocellular and bile duct carcinogenesis is a multiplex process, caused by various genetic and epigenetic alterations, the influence of environmental factors, as well as the implication of the gut microbiome, which was undervalued in the previous years. The molecular and immunological analysis of the above malignancies, as well as the identification of the crucial role of intestinal microbiota for hepatic and biliary pathogenesis, opened the horizon for novel therapeutic strategies, such as immunotherapy, and enhanced the overall survival of cancer patients. Some of the immunotherapy strategies that are either clinically applied or under pre-clinical studies include monoclonal antibodies, immune checkpoint blockade, cancer vaccines, as well as the utilization of oncolytic viral vectors and Chimeric antigen, receptor-engineered T (CAR-T) cell therapy. In this current review, we will shed light on the recent therapeutic modalities for the above primary liver cancers, as well as on the methods for the enhancement and optimization of anti-tumor immunity.

Study on the Characteristics of Small-Molecule Kinase Inhibitors-Related Drug-Induced Liver Injury

Background and Aim: More than half of the small-molecule kinase inhibitors (KIs) induced liver injury clinically. Meanwhile, studies have shown a close relationship between mitochondrial damage and drug-induced liver injury (DILI). We aimed to study KIs and the binding between drugs and mitochondrial proteins to find factors related to DILI occurrence.

Methods: A total of 1,223 oral FDA-approved drugs were collected and analyzed, including 44 KIs. Fisher’s exact test was used to analyze DILI potential and risk of different factors. A total of 187 human mitochondrial proteins were further collected, and high-throughput molecular docking was performed between human mitochondrial proteins and drugs in the data set. The molecular dynamics simulation was used to optimize and evaluate the dynamic binding behavior of the selected mitochondrial protein/KI complexes.

Results: The possibility of KIs to produce DILI is much higher than that of other types (OR = 46.89, p = 9.28E-13). A few DILI risk factors were identified, including molecular weight (MW) between 400 and 600, the defined daily dose (DDD) ≥ 100 mg/day, the octanol–water partition coefficient (LogP) ≥ 3, and the degree of liver metabolism (LM) more than 50%. Drugs that met this combination of rules were found to have a higher DILI risk than controls (OR = 8.28, p = 4.82E-05) and were more likely to cause severe DILI (OR = 8.26, p = 5.06E-04). The docking results showed that KIs had a significant higher affinity with human mitochondrial proteins (p = 4.19E-11) than other drug types. Furthermore, the five proteins with the lowest docking score were selected for molecular dynamics simulation, and the smallest fluctuation of the backbone RMSD curve was found in the protein 5FS8/KI complexes, which indicated the best stability of the protein 5FS8 bound to KIs.

Conclusions: KIs were found to have the highest odds ratio of causing DILI. MW was significantly related to the production of DILI, and the average docking scores of KI drugs were found to be significantly different from other classes. Further analysis identified the top binding mitochondrial proteins for KIs, and specific binding sites were analyzed. The optimization of molecular docking results by molecular dynamics simulation may contribute to further studying the mechanism of DILI.

Lapatinib ditosylate rescues memory impairment in D-galactose/ovariectomized rats: Potential repositioning of an anti-cancer drug for the treatment of Alzheimer's disease

Epidermal growth factor receptor (EGFR) signaling plays a substantial role in learning and memory. The upregulation of EGFR has been embroiled in the pathophysiology of Alzheimer's disease (AD). Nevertheless, most of EGFR-tyrosine kinase inhibitors (EGFR-TKIs) have been extensively studied for non-CNS diseases such as cancer and rheumatoid arthritis. TKIs targeting-based research in neurodegenerative disorders sounds to be lagging behind those of other diseases. Hence, this study aims to explore the molecular signaling pathways and the efficacy of treatment with lapatinib ditosylate (LAP), as one of EGFR-TKIs that has not yet been investigated in AD, on cognitive decline induced by ovariectomy (OVX) with chronic administration of D-galactose (D-gal) in female Wistar albino rats. OVX rats were injected with 150 mg/kg/day D-gal ip for 8 weeks to induce AD. Administration of 100 mg/kg/day LAP p.o. for 3 weeks starting after the 8^th week of D-gal administration improved memory and debilitated histopathological alterations. LAP decreased the expression of GFAP, p-tau, and Aβ 1-42. Besides, it reduced EGFR, HER-2, TNF-α, NOX-1, GluR-II, p38 MAPK, and p-mTOR. LAP increased nitrite, and neuronal pro-survival transduction proteins; p-PI3K, p-AKT, and p-GSK-3β levels. Taken together, these findings suggest the role of LAP in ameliorating D-gal-induced AD in OVX rats via activating the pro-survival pathway; PI3K-Akt-GSK-3β, while inhibiting p-mTOR, NOX-1, and p38 MAPK pathways. Moreover, this research offered a significant opportunity to advance awareness of the repositioning of TKI anti-cancer drugs for the treatment of AD.