Multikinase Inhibitors Induce Cutaneous Toxicity through OAT6-Mediated Uptake and MAP3K7-Driven Cell Death

Safety profile of vascular endothelial growth factor receptor tyrosine-kinase inhibitors in pediatrics: a pharmacovigilance disproportionality analysis

Introduction: existing research on children consists primarily of phase I/II clinical trials for VEGFR-TKI. System reports of safety on the use of VEGFR-TKI in pediatrics are lacking. Aim: to investigate the safety profiles of VEGFR-TKI in pediatrics via the FDA Adverse Event Reporting System (FAERS). Method: data regarding VEGFR-TKIs were extracted from the FAERS between 2004Q1 to 2022Q3 and categorized by the Medical Dictionary for Regulatory Activities (MedDRA). Population characteristics were analyzed, and reporting odds ratio (ROR) was performed to identify risk signals associated with VEGFR-TKI. Results: 53,921 cases containing 561 children were identified in the database from 18 May 2005, to 30 September 2022. Among those in the system organ class, skin, subcutaneous tissue disorders, and blood and lymphatic system disorders in pediatrics contributed to over 140 cases. Palmar-plantar eythrodysesthesia syndrome (PPES) in VEGFR-TKI presented the most significant 340.9 (95% 229.2-507.0). And pneumothorax also gave a high reporting odds ratio of 48.9 (95% 34.7-68.9). For a specific drug, musculoskeletal pain gave a ROR of 78.5 (95% 24.4-252.6) in cabozantinib and oesophagitis in lenvatinib with a ROR of 95.2 (95% 29.5-306.9). Additionally, hypothyroidism presented a high signal, especially sunitinib, with a ROR of 107.8 (95% 37.6-308.7). Conclusion: the present study explored the safety profile of VEGFR-TKI in pediatrics using the FAERS database. Multiple skin and subcutaneous tissue disorders, as well as blood and lymphatic system disorders, were common VEGFR-TKI-related AEs in system organ class. No serious hepatobiliary AEs were detected. For the specific AEs, PPES and pneumothorax were VEGFR-TKI-related AEs that presented significantly higher signals than those in the general population.

Evaluation of Delayed-Type Hypersensitivity to Antineoplastic Drugs-An Overview

Nowadays, clinical practice encounters the problem of delayed-type hypersensitivity (DTH) induced by several drugs. Antineoplastic treatments are among the drugs which show an elevated proportion of DHT reactions, leading to the worsening of patients' quality of life. The range of symptoms in DHT reactions can vary from mild, such as self-limiting maculopapular eruptions, to severe, such as Stevens-Johnson Syndrome. The development of these reactions supposes a negative impact, not only by limiting patients' quality of life, but also leading to economic loss due to market withdrawal of the affected drugs and high hospitalization costs. However, despite this problem, there are no available standard in vitro or in vivo methods that allow for the evaluation of the sensitizing potential of drugs in the preclinical phase. Therefore, the aim of this review is to summarize the skin reactions caused by the different antineoplastic families, followed by a comprehensive evaluation of the in vitro and in vivo methods used to detect DTHs and that could be suitable to test antineoplastic hypersensitivity reactions.

Evaluation of Antineoplastic Delayed-Type Hypersensitivity Skin Reactions In Vitro

Delayed-type hypersensitivity (DTH) is caused by a broad number of drugs used in clinic, and antineoplastic drugs show an elevated proportion of DTH, which potentially affects the quality of life of patients. Despite the serious problem and the negative economic impact deriving from market withdrawal of such drugs and high hospitalization costs, nowadays, there are no standard validated methods in vitro or in vivo to evaluate the sensitizing potential of drugs in the preclinical phase. Enhanced predictions in preclinical safety evaluations are really important, and for that reason, the aim of our work is to adapt in vitro DPRA, ARE-Nrf2 luciferase KeratinoSens^TM, and hCLAT assays for the study of the sensitizing potential of antineoplastic agents grouped by mechanism of action. Our results reveal that the above tests are in vitro techniques able to predict the sensitizing potential of the tested antineoplastics. Moreover, this is the first time that the inhibition of the VEGFR1 pathway has been identified as a potential trigger of DTH.

Nitric oxide in multikinase inhibitor-induced hand-foot skin reaction

Hand-foot skin reaction (HFSR) is the most debilitating and prevalent side effect caused by multikinase inhibitors (MKIs) that share vascular endothelial growth factor receptor (VEGFR) as the common inhibition target, such as sorafenib, regorafenib, axitinib, etc. Though not life-threatening, HFSR can significantly deteriorate patients' quality of life and jeopardize the continuity of cancer therapy. Despite years of efforts, there are no FDA-approved treatments for HFSR and the understanding of the precise pathogenic mechanism is still limited. In this study, we hypothesized that nitric oxide has the potential therapeutic effect to reverse the toxicity caused by MKI through upregulation of several VEGF/VEGFR downstream signaling pathways. We found that glyceryl trinitrate (GTN), a nitric oxide donor, could stimulate cell proliferation, migration, and protect cells from apoptosis induced by MKIs in vitro. Local application of GTN mitigated tissue damage in a rat model, while not impacting the anti-tumor effect of the MKI in HepG2 tumor-bearing mice. Finally, GTN ointment alleviated cutaneous damages and improved quality of life in 6 HFSR patients. Our study proposed and validated the mechanism to counteract VEGFR inhibition, providing GTN as the potential treatment to MKI-induced HFSR, which may further improve the therapeutic window of various MKI based cancer therapies.

Discrimination of hand-foot skin reaction caused by tyrosine kinase inhibitors based on direct keratinocyte toxicity and vascular endothelial growth factor receptor-2 inhibition

Tyrosine kinase inhibitors (TKIs) are molecular-targeted anticancer drugs. Their benefits are limited by dermal toxicities, including hand-foot skin reaction (HFSR), which is commonly found in skin areas subjected to friction. The present study aimed to explain the incidence of HFSR in patients treated with TKIs by focusing on keratinocyte toxicity and inhibition of vascular endothelial growth factor receptor (VEGFR), which plays an essential role in angiogenesis. Mice with gene knockout for the immunosuppressive cytokine interleukin-10 exhibited HFSR-like phenotypes, such as cytotoxicity in keratinocytes and increased number and size of blood vessels after repeated doses of regorafenib, sorafenib, and pazopanib, all of which cause high incidence of HFSR, in combination with tape-stripping mimicking skin damage at the friction site. Comprehensive examination of the direct cytotoxic effects of 21 TKIs on primary cultured human keratinocytes revealed that 18 of them reduced the cell viability dose-dependently. Importantly, the ratio of the trough concentration in patients (C_trough) to the LC₅₀ values of cell viability reduction was higher than unity for four HFSR-inducing TKIs, suggesting that these TKIs cause keratinocyte toxicity at clinically relevant concentrations. In addition, eight HFSR-inducing TKIs caused inhibition of VEGFR-2 kinase activity, which was validated by their ratios of C_trough to the obtained IC_50,VEGFR-2 of more than unity. All 12 TKIs with no reported incidence of HFSR exhibited less than unity values for both C_trough/LC_{50,keratinocytes} and C_trough/IC_50,VEGFR-2. These results suggested that a combination of keratinocyte toxicity and VEGFR-2 inhibition may explain the incidence of HFSR upon TKI usage in humans.

TAK1 Is a Novel Target in Hepatocellular Carcinoma and Contributes to Sorafenib Resistance

BACKGROUND & AIMS

Identifying novel and actionable targets in hepatocellular carcinoma (HCC) remains an unmet medical need. TAK1 was originally identified as a transforming growth factor-β-activated kinase and was further proved to phosphorylate and activate numerous downstream targets and promote cancer progression. However, the role of TAK1 in developed HCC progression and targeted therapy resistance is poorly understood.

METHODS

The expression of TAK1 or MTDH in HCC cell lines, tumor tissues, and sorafenib-resistant models was analyzed by in silico analysis, quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemistry. In vivo and in vitro experiments were introduced to examine the function of TAK1 or MTDH in HCC and sorafenib resistance using small interfering RNA and pharmacologic inhibitors in combination with or without sorafenib. Co-immunoprecipitation and RNA immunoprecipitation were carried out to determine the binding between TAK1 and FBXW2 or between MTDH and FBXW2 mRNA. Protein half-life and in vitro ubiquitination experiment was performed to validate whether FBXW2 regulates TAK1 degradation.

RESULTS

Our findings unraveled the clinical significance of TAK1 in promoting HCC and sorafenib resistance. We identified a novel E3 ubiquitin ligase, FBXW2, targeting TAK1 for K48-linked polyubiquitylation and subsequent degradation. We also found that MTDH contributes to TAK1 up-regulation in HCC and sorafenib resistance through binding to FBXW2 mRNA and accelerates its degradation. Moreover, combination of TAK1 inhibitor and sorafenib suppressed the growth of sorafenib-resistant HCCLM3 xenograft in mouse models.

CONCLUSIONS

These results revealed novel mechanism underlying TAK1 protein degradation and highlighted the therapeutic value of targeting TAK1 in suppressing HCC and overcoming sorafenib resistance.

Apatinib-Induced Hand-Foot Skin Reaction in Chinese Patients With Liver Cancer

Apatinib, an anti-tumor drug selectively targeting VEGFR2 (Vascular Endothelia Growth Factor Recpetor-2), has been proven effective in Chinese patients with liver cancer. Generally, treatment with apatinib achieves 16.1% of the overall objective remission rate (ORR) and 55.83% of the disease control rate (DCR) in Chinese patients with liver cancer. However, the prevalence of apatinib-induced hand–foot skin reaction (AI-HFSR) is noticeably high. The incidence of AI-HFSR is about 50.5%, of which Grades 1/2 and 3 are 38.8 and 11.6%, respectively. In addition, potential molecular mechanisms underlying the development of AI-HFSR are poorly understood and urgently needed to be investigated histologically. In this review, we summarize and review the current efficacy of apatinib and the prevalence of AI-HFSR in Chinese patients with liver cancer. Besides, we postulate the potential mechanisms underlying the development of AI-HFSR and discuss the optimal clinical management for this unwanted cutaneous side effect.

Solute transporters and malignancy: establishing the role of uptake transporters in breast cancer and breast cancer metastasis

The solute carrier (SLC) superfamily encompasses a large variety of membrane-bound transporters required to transport a diverse array of substrates over biological membranes. Physiologically, they are essential for nutrient uptake, ion transport and waste removal. However, accumulating evidence suggest that up- and/or downregulation of SLCs may play a pivotal role in the pathogenesis of human malignancy. Endogenous substrates of SLCs include oestrogen and its conjugates, the handling of which may be of importance in hormone-dependent cancers. The SLCs play a significant role in the handling of therapeutic agents including anticancer drugs. Differential SLC expression in cancers may, therefore, impact on the efficacy of treatments. However, there is also a small body of evidence to suggest the dysregulated expression of some of these transporters may be linked to cancer metastasis. This review draws on the current knowledge of the roles of SLC transporters in human cancers in order to highlight the potential significance of these solute carriers in breast cancer pathogenesis and treatment.

Influence of Probenecid on the Pharmacokinetics and Pharmacodynamics of Sorafenib

Prior studies have demonstrated an organic anion transporter 6 (OAT6)-mediated accumulation of sorafenib in keratinocytes. The OAT6 inhibitor probenecid decreases sorafenib uptake in skin and might, therefore, decrease sorafenib-induced cutaneous adverse events. Here, the influence of probenecid on sorafenib pharmacokinetics and toxicity was investigated. Pharmacokinetic sampling was performed in 16 patients on steady-state sorafenib treatment at days 1 and 15 of the study. Patients received sorafenib (200–800 mg daily) in combination with probenecid (500 mg two times daily (b.i.d.)) on days 2–15. This study was designed to determine bioequivalence with geometric mean Area under the curve from zero to twelve hours (AUC_{0–12 h}) as primary endpoint. During concomitant probenecid, sorafenib plasma AUC_{0–12 h} decreased by 27% (90% CI: −38% to −14%; P < 0.01). Furthermore, peak and trough levels of sorafenib, as well as sorafenib concentrations in skin, decreased to a similar extent in the presence of probenecid. The metabolic ratio of sorafenib-glucuronide to parent drug increased (+29%) in the presence of probenecid. A decrease in systemic sorafenib concentrations during probenecid administration seems to have influenced cutaneous concentrations. Since sorafenib-glucuronide concentrations increased compared with sorafenib and sorafenib-N-oxide, probenecid may have interrupted enterohepatic circulation of sorafenib by inhibition of the organic anion transporting polypeptides 1B1 (OATP1B1). Sorafenib treatment with probenecid is, therefore, not bioequivalent to sorafenib monotherapy. A clear effect of probenecid on sorafenib toxicity could not be identified in this study.

Low-Dose Sorafenib Acts as a Mitochondrial Uncoupler and Ameliorates Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH) is becoming one of the leading causes of hepatocellular carcinoma (HCC). Sorafenib is the only first-line therapy for advanced HCC despite its serious adverse effects. Here, we report that at an equivalent of approximately one-tenth the clinical dose for HCC, sorafenib treatment effectively prevents the progression of NASH in both mice and monkeys without any observed significant adverse events. Mechanistically, sorafenib's benefit in NASH is independent of its canonical kinase targets in HCC, but involves the induction of mild mitochondrial uncoupling and subsequent activation of AMP-activated protein kinase (AMPK). Collectively, our findings demonstrate a previously unappreciated therapeutic effect and signaling mechanism of low-dose sorafenib treatment in NASH. We envision that this new therapeutic strategy for NASH has the potential to translate into a beneficial anti-NASH therapy with fewer adverse events than is observed in the drug's current use in HCC.

Repurposing Tyrosine Kinase Inhibitors to Overcome Multidrug Resistance in Cancer: A Focus on Transporters and Lysosomal Sequestration

Tyrosine kinase inhibitors (TKIs) are being increasingly used to treat various malignancies. Although they were designed to target aberrant tyrosine kinases, they are also intimately linked with the mechanisms of multidrug resistance (MDR) in cancer cells. MDR-related solute carrier (SLC) and ATB-binding cassette (ABC) transporters are responsible for TKI uptake and efflux, respectively. However, the role of TKIs appears to be dual because they can act as substrates and/or inhibitors of these transporters. In addition, several TKIs have been identified to be sequestered into lysosomes either due to their physiochemical properties or via ABC transporters expressed on the lysosomal membrane. Since the development of MDR represents a great concern in anticancer treatment, it is important to elucidate the interactions of TKIs with MDR-related transporters as well as to improve the properties that would prevent TKIs from diffusing into lysosomes. These findings not only help to avoid MDR, but also help to define the possible impact of combining TKIs with other anticancer drugs, leading to more efficient therapy and fewer adverse effects in patients.

Higher Systemic Exposure to Unbound Active Metabolites of Regorafenib Is Associated With Short Progression-Free Survival in Colorectal Cancer Patients

Regorafenib treatment improves survival of patients with metastatic colorectal cancer, but it is also characterized by detrimental side effects that may require modified dosing or interval schedules. Regorafenib is metabolized by cytochrome P450 3A4 in the liver to its active metabolites, M-2 and M-5. We examined area under the unbound plasma concentration-time curve (AUCu) to these compounds to establish pharmacokinetic bases for individualized dosing strategies. The plasma protein binding of M-2 and M-5 was approximately 10-fold lower than that of regorafenib, whereas AUCu values for active metabolites on both days 1 and 15 were significantly higher than that of regorafenib. Patients with higher AUCu values of M-2 or M-5 on day 1 showed significantly shorter progression-free survival than others, likely due, at least in part, to treatment discontinuation as a result of adverse events, especially occurred during first cycle.

Clinical study for external Chinese herbal medicine LC09 treating hand-foot skin reaction associated with the antitumor targeted drugs: Protocol for a prospective, randomized, controlled, double-blind, and monocentric clinical trial

BACKGROUND

Molecular targeted anticancer drugs such as multikinase inhibitors have shown obvious therapeutic advantages in a variety of tumors. The occurrence of hand-foot skin reaction (HFSR) is positively correlated with therapeutic effect, but it is also the most common cause of dose limiting toxicity for this treatment. This can lead to interruption or decrement of the treatment, a reduction in quality of life for patients, as well as potentially leading to secondary infections. As a result, the curative effect of targeted anticancer drugs will be negatively impacted. Currently, there is no certain and effective therapy. External use of Chinese herb medicine LC09 in the early treatment of HFSR has shown positive outcomes, but it is necessary to carry out further clinical research to confirm.

OBJECTIVES

The purpose of this study was to investigate the efficacy and safety of topical soaks of Chinese herbal medicine LC09 for HFSR induced by molecular targeted anticancer drugs.

METHODS

The trial is a prospective, randomized, controlled, double-blind, monocentric, and interventional study. A total of 66 patients with HFSR will be recruited and randomly assigned to receive either LC09 Granules or placebo. The primary outcomes are the assessment of HFSR grade and pain score. The secondary outcomes are the evaluation of the quality of life, incidence of targeted drug dosage reduction, and incidence of targeted drug withdrawal.

DISCUSSION

This prospective, randomized clinical trial will provide valuable data regarding the efficacy and safety of topical soak treatments with LC09 granules for HFSR. Positive results would provide evidence-based complementary therapeutic approach future treatments of HFSR.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, http://www.chictr.org.cn, ChiCTR1900023679. Registered on 7 June 2019.

Solute Carrier Transportome in Chemotherapy-Induced Adverse Drug Reactions

Members of the solute carrier (SLC) family of transporters are responsible for the cellular influx of a broad range of endogenous compounds and xenobiotics. These proteins are highly expressed in the gastrointestinal tract and eliminating organs such as the liver and kidney, and are considered to be of particular importance in governing drug absorption and elimination. Many of the same transporters are also expressed in a wide variety of organs targeted by clinically important anticancer drugs, directly affect cellular sensitivity to these agents, and indirectly influence treatment-related side effects. Furthermore, targeted intervention strategies involving the use of transport inhibitors have been recently developed, and have provided promising lead candidates for combinatorial therapies associated with decreased toxicity. Gaining a better understanding of the complex interplay between transporter-mediated on-target and off-target drug disposition will help guide the further development of these novel treatment strategies to prevent drug accumulation in toxicity-associated organs, and improve the safety of currently available treatment modalities. In this report, we provide an update on this rapidly emerging field with particular emphasis on anticancer drugs belonging to the classes of taxanes, platinum derivatives, nucleoside analogs, and anthracyclines.

Targeted Therapy for Advanced Thyroid Cancer: Kinase Inhibitors and Beyond

The treatment of advanced thyroid cancer has undergone rapid evolution in the last decade, with multiple kinase inhibitor drug approvals for each subtype of thyroid cancer and a number of other commercially available drugs that have been studied for this indication. Although most of the US Food and Drug Administration (FDA)-approved drugs are antiangiogenic multikinase inhibitors-vandetanib, cabozantinib, sorafenib, lenvatinib-there are two FDA indications that are mutation specific-dabrafenib/trametinib for BRAF-mutated anaplastic thyroid cancer and larotrectinib for NTRK-fusion thyroid cancer. Furthermore, other mutation-specific drugs, immunotherapies, and novel strategies for advanced thyroid cancer are under investigation. Understanding the molecular basis of thyroid cancer, the drugs of interest for treatment of advanced thyroid cancer, and how these drugs can be administered safely and in the appropriate clinical scenario are the topics of this review.

Sorafenib-associated hand-foot skin reaction: practical advice on diagnosis, mechanism, prevention, and management

Introduction: Sorafenib is a multitargeted tyrosine kinase inhibitor, which has been mainly used in the treatment of advanced hepatocellular carcinoma and renal cancer. However, hand-foot skin reaction (HFSR), as one of the most common adverse reactions, have hindered its long-term clinical application. At present, the mechanism of its occurrence has not been clearly studied and it leads to the lack of effective means of intervention. This article reviews known mechanism and management methods of HFSR caused by sorafenib.Areas covered: The author reviews HFSR caused by the treatment of sorafenib including the mechanism and management. English language reports located through PubMed are reviewed.Expert opinion: There are some conjectures about the mechanism of HFSR. However, the mechanism of HFSR induced by sorafenib is still unclear at present. In the absence of understanding the mechanism of HFSR, the most common method for clinical treatment of sorafenib-induced HFSR is dose down-regulation or discontinuation of treatment, which affects efficacy and even survival. Future research should focus on the mechanism of HFSR to find out new ways for prevention. Precautionary measures before the occurrence of HFSR can also be studied in the future.

Sorafenib Population Pharmacokinetics and Skin Toxicities in Children and Adolescents with Refractory/Relapsed Leukemia or Solid Tumor Malignancies

PURPOSE

To determine the pharmacokinetics and skin toxicity profile of sorafenib in children with refractory/relapsed malignancies.

PATIENTS AND METHODS

Sorafenib was administered concurrently or sequentially with clofarabine and cytarabine to patients with leukemia or with bevacizumab and cyclophosphamide to patients with solid tumor malignancies. The population pharmacokinetics (PPK) of sorafenib and its metabolites and skin toxicities were evaluated.

RESULTS

In PPK analysis, older age, bevacizumab and cyclophosphamide regimen, and higher creatinine were associated with decreased sorafenib apparent clearance (CL/f; P < 0.0001 for all), and concurrent clofarabine and cytarabine administration was associated with decreased sorafenib N-oxide CL/f (P = 7e-4). Higher bilirubin was associated with decreased sorafenib N-oxide and glucuronide CL/f (P = 1e-4). Concurrent use of organic anion-transporting polypeptide 1B1 inhibitors was associated with increased sorafenib and decreased sorafenib glucuronide CL/f (P < 0.003). In exposure-toxicity analysis, a shorter time to development of grade 2-3 hand-foot skin reaction (HFSR) was associated with concurrent (P = 0.0015) but not with sequential (P = 0.59) clofarabine and cytarabine administration, compared with bevacizumab and cyclophosphamide, and with higher steady-state concentrations of sorafenib (P = 0.0004) and sorafenib N-oxide (P = 0.0275). In the Bayes information criterion model selection, concurrent clofarabine and cytarabine administration, higher sorafenib steady-state concentrations, larger body surface area, and previous occurrence of rash appeared in the four best two-predictor models of HFSR. Pharmacokinetic simulations showed that once-daily and every-other-day sorafenib schedules would minimize exposure to sorafenib steady-state concentrations associated with HFSR.

CONCLUSIONS

Sorafenib skin toxicities can be affected by concurrent medications and sorafenib steady-state concentrations. The described PPK model can be used to refine exposure-response relations for alternative dosing strategies to minimize skin toxicity.

Clinically relevant drug interactions with multikinase inhibitors: a review

Multikinase inhibitors (MKIs), including the tyrosine kinase inhibitors (TKIs), have rapidly become an established factor in daily (hemato)-oncology practice. Although the oral route of administration offers improved flexibility and convenience for the patient, challenges arise in the use of MKIs. As MKIs are prescribed extensively, patients are at increased risk for (severe) drug–drug interactions (DDIs). As a result of these DDIs, plasma pharmacokinetics of MKIs may vary significantly, thereby leading to high interpatient variability and subsequent risk for increased toxicity or a diminished therapeutic outcome. Most clinically relevant DDIs with MKIs concern altered absorption and metabolism. The absorption of MKIs may be decreased by concomitant use of gastric acid-suppressive agents (e.g. proton pump inhibitors) as many kinase inhibitors show pH-dependent solubility. In addition, DDIs concerning drug (uptake and efflux) transporters may be of significant clinical relevance during MKI therapy. Furthermore, since many MKIs are substrates for cytochrome P450 isoenzymes (CYPs), induction or inhibition with strong CYP inhibitors or inducers may lead to significant alterations in MKI exposure. In conclusion, DDIs are of major concern during MKI therapy and need to be monitored closely in clinical practice. Based on the current knowledge and available literature, practical recommendations for management of these DDIs in clinical practice are presented in this review.

MAP3K7 is recurrently deleted in pediatric T-lymphoblastic leukemia and affects cell proliferation independently of NF-κB

BACKGROUND

Deletions of 6q15-16.1 are recurrently found in pediatric T-cell acute lymphoblastic leukemia (T-ALL). This chromosomal region includes the mitogen-activated protein kinase kinase kinase 7 (MAP3K7) gene which has a crucial role in innate immune signaling and was observed to be functionally and prognostically relevant in different cancer entities. Therefore, we correlated the presence of MAP3K7 deletions with clinical parameters in a cohort of 327 pediatric T-ALL patients and investigated the function of MAP3K7 in the T-ALL cell lines CCRF-CEM, Jurkat and MOLT-4.

METHODS

MAP3K7 deletions were detected by multiplex ligation-dependent probe amplification (MLPA). T-ALL cell lines were transduced with adeno-associated virus (AAV) vectors expressing anti-MAP3K7 shRNA or a non-silencing shRNA together with a GFP reporter. Transduction efficiency was measured by flow cytometry and depletion efficiency by RT-PCR and Western blots. Induction of apoptosis was measured by flow cytometry after staining with PE-conjugated Annexin V. In order to assess the contribution of NF-κB signaling to the effects of MAP3K7 depletion, cells were treated with TNF-α and cell lysates analyzed for components of the NF-κB pathway by Western blotting and for expression of the NF-κB target genes BCL2, CMYC, FAS, PTEN and TNF-α by RT-PCR.

RESULTS

MAP3K7 is deleted in approximately 10% and point-mutated in approximately 1% of children with T-ALL. In 32 of 33 leukemias the deletion of MAP3K7 also included the adjacent CASP8AP2 gene. MAP3K7 deletions were associated with the occurrence of SIL-TAL1 fusions and a mature immunophenotype, but not with response to treatment and outcome. Depletion of MAP3K7 expression in T-ALL cell lines by shRNAs slowed down proliferation and induced apoptosis, but neither changed protein levels of components of NF-κB signaling nor NF-κB target gene expression after stimulation with TNF-α.

CONCLUSIONS

This study revealed that the recurrent deletion of MAP3K7/CASP8AP2 is associated with SIL-TAL1 fusions and a mature immunophenotype, but not with response to treatment and risk of relapse. Homozygous deletions of MAP3K7 were not observed, and efficient depletion of MAP3K7 interfered with viability of T-ALL cells, indicating that a residual expression of MAP3K7 is indispensable for T-lymphoblasts.

Severe cutaneous adverse reactions induced by targeted anticancer therapies and immunotherapies

With the increasing use of targeted anticancer drugs and immunotherapies, there have been a substantial number of reports concerning life-threatening severe cutaneous adverse reactions (SCARs), including Stevens–Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug rash with eosinophilia and systemic symptoms, drug-induced hypersensitivity syndrome, and acute generalized exanthematous pustulosis. Although the potential risks and characteristics for targeted anticancer agent- and immunotherapy-induced SCAR were not well understood, these serious adverse reactions usually result in morbidity and sequela. As a treatment guideline for this devastating condition is still unavailable, prompt withdrawal of causative drugs is believed to be a priority of patient management. In this review, we outline distinct types of SCARs caused by targeted anticancer therapies and immunotherapies. Also, we discuss the clinical course, latency, concomitant medication, tolerability of rechallenge or alternatives, tumor response, and mortality associated with these devastating conditions. Imatinib, vemurafenib, and rituximab were the top three offending medications that most commonly caused SJS/TEN, while EGFR inhibitors were the group of drugs that most frequently induced SJS/TEN. For drug rash with eosinophilia and systemic symptoms/drug-induced hypersensitivity syndrome and acute generalized exanthematous pustulosis, imatinib was also the most common offending drug. Additionally, we delineated 10 SCAR cases related to innovative immunotherapies, including PD1 and CTLA4 inhibitors. There was a wide range of latency periods: 5.5–91 days (median). Only eight of 16 reported patients with SCAR showed clinical responses. Targeted anticancer drugs and immunotherapies can lead to lethal SCAR (14 deceased patients were identified as suffering from SJS/TEN). The mortality rate of TEN was high: up to 52.4%. The information compiled herein will serve as a solid foundation to formulate ideas for early recognition of SCAR and to discontinue offending drugs for better management.

Genetic Heterogeneity of SLC22 Family of Transporters in Drug Disposition. J Pers Med. 2018;8. [PMID: 29659532 PMCID: PMC6023491 DOI: 10.3390/jpm8020014]

An important aspect of modern medicine is its orientation to achieve more personalized pharmacological treatments. In this context, transporters involved in drug disposition have gained well-justified attention. Owing to its broad spectrum of substrate specificity, including endogenous compounds and xenobiotics, and its strategical expression in organs accounting for drug disposition, such as intestine, liver and kidney, the SLC22 family of transporters plays an important role in physiology, pharmacology and toxicology. Among these carriers are plasma membrane transporters for organic cations (OCTs) and anions (OATs) with a marked overlap in substrate specificity. These two major clades of SLC22 proteins share a similar membrane topology but differ in their degree of genetic variability. Members of the OCT subfamily are highly polymorphic, whereas OATs have a lower number of genetic variants. Regarding drug disposition, changes in the activity of these variants affect intestinal absorption and target tissue uptake, but more frequently they modify plasma levels due to enhanced or reduced clearance by the liver and secretion by the kidney. The consequences of these changes in transport-associated function markedly affect the effectiveness and toxicity of the treatment in patients carrying the mutation. In solid tumors, changes in the expression of these transporters and the existence of genetic variants substantially determine the response to anticancer drugs. Moreover, chemoresistance usually evolves in response to pharmacological and radiological treatment. Future personalized medicine will require monitoring these changes in a dynamic way to adapt the treatment to the weaknesses shown by each tumor at each stage in each patient.

Anticancer Drugs Induced Severe Adverse Cutaneous Drug Reactions: An Updated Review on the Risks Associated with Anticancer Targeted Therapy or Immunotherapies

Cutaneous adverse drug reactions are commonly seen in patients with anticancer drug treatment. Anticancer drugs, including chemotherapy, target therapy, and recent immunotherapy causing skin reactions ranging from mild skin rash to life-threatening severe cutaneous adverse reactions (SCARs), such as Stevens-Johnson syndrome (SJS) and toxic epidermal necrosis (TEN) with increase morbidity and mortality while they are receiving cancer treatments, have been proposed to be a result of direct skin toxicity or drug hypersensitivity reactions (these are proposed mechanism, not definite). Differentiating SCARs from other more commonly seen reactions with a better outcome help prevent discontinuation of therapy and inappropriate use of systemic immunosuppressants for presumable allergic reactions, of which will affect the clinical outcome. In this article, we have reviewed published articles from 1950 to August 2017 for SJS/TEN associated with anticancer drugs, including chemotherapy, targeted therapy, and immunotherapy. We aimed to provide an overview of SJS/TEN associated with anticancer drugs to increase clinician recognition and accelerate future studies on the pathomechanism and managements.

Hypoxia-induced upregulation of BMX kinase mediates therapeutic resistance in acute myeloid leukemia

Oncogenic addiction to the Fms-like tyrosine kinase 3 (FLT3) is a hallmark of acute myeloid leukemia (AML) that harbors the FLT3-internal tandem duplication (FLT3-ITD) mutation. While FLT3 inhibitors like sorafenib show initial therapeutic efficacy, resistance rapidly develops through mechanisms that are incompletely understood. Here, we used RNA-Seq-based analysis of patient leukemic cells and found that upregulation of the Tec family kinase BMX occurs during sorafenib resistance. This upregulation was recapitulated in an in vivo murine FLT3-ITD-positive (FLT3-ITD+) model of sorafenib resistance. Mechanistically, the antiangiogenic effects of sorafenib led to increased bone marrow hypoxia, which contributed to HIF-dependent BMX upregulation. In in vitro experiments, hypoxia-dependent BMX upregulation was observed in both AML and non-AML cell lines. Functional studies in human FLT3-ITD+ cell lines showed that BMX is part of a compensatory signaling mechanism that promotes AML cell survival during FLT3 inhibition. Taken together, our results demonstrate that hypoxia-dependent upregulation of BMX contributes to therapeutic resistance through a compensatory prosurvival signaling mechanism. These results also reveal the role of off-target drug effects on tumor microenvironment and development of acquired drug resistance. We propose that the bone marrow niche can be altered by anticancer therapeutics, resulting in drug resistance through cell-nonautonomous microenvironment-dependent effects.

Capsaicin exerts synergistic antitumor effect with sorafenib in hepatocellular carcinoma cells through AMPK activation

In this study, we investigated the antitumoral effects of combined treatment using sorafenib and capsaicin in hepatocellular carcinoma (HCC) cells. Here we showed that the combination of the two drugs had a much stronger inhibitory effect on both HepG2 and Huh-7 human HCC cells growth than either drug alone. The isobolograms demonstrated that the combinations investigated in this study produced a synergistic interaction. In the combination treatment using capsaicin and sorafenib, increased apoptosis, followed by the activation of caspase-9 and PARP, was observed. In addition, the present study demonstrated that sorafenib treatment induces activation of Akt, probably as a mechanism of resistance, whereas capsaicin inhibits Akt providing a possible pathway whereby capsaicin sensitizes to sorafenib in HCC cells. Moreover, capsaicin singly and the combination of capsaicin and sorafenib induce AMPK activation and Acetyl CoA carboxylase phosphorylation in HCC cells. Knocking down of AMPK by selective siRNA abrogates capsaicin-induced Akt inhibition, suggesting the involvement of AMPK in the antiproliferative effect. In vivo experiments further showed that that the anti-tumor effect of sorafenib was enhanced by its combination with 2.5 mg/Kg of capsaicin. Overall, these results show that combined treatment with capsaicin and sorafenib might improve sorafenib sensitivity and therefore it represents a promising and attractive strategy for the treatment of HCC.

Sorafenib stimulates human skin type mast cell degranulation and maturation

BACKGROUND

Sorafenib is a multi-kinase inhibitor for treating advanced hepatocellular and renal cell carcinomas by targeting various types of receptors and signaling molecules, including vascular endothelial growth factor receptors, platelet-derived growth factor receptor, and Raf-1. Sorafenib may cause diverse cutaneous adverse reactions, including hand-foot reaction, facial and scalp eruptions, alopecia and pruritus. However, the mechanism of these adverse effects has not been well-investigated.

OBJECTIVE

Mast cells (MCs) are reported to be associated with various types of skin diseases. To investigate the mechanism of sorafenib-induced cutaneous adverse effects, we focused on MCs in situ.

METHODS

We evaluated skin samples of organ cultured normal human skin treated with sorafenib using c-Kit, tryptase, and stem cell factor (SCF), Ki-67, and TUNEL immunohistochemistry as well as quantitative real-time polymerase chain reaction to evaluate MC number, degranulation, proliferation, and apoptosis in situ.

RESULTS

Sorafenib significantly increased the number and degranulation of skin-type MCs compared with the vehicle-treated control group in situ. However, sorafenib did not affect MC proliferation and apoptosis, suggesting that it stimulated MC maturation from resident precursors. Furthermore, sorafenib increased SCF expression in situ. The increase in MC number by sorafenib was abrogated by co-administration of SCF neutralizing antibody or the phosphoinositide 3-kinase (PI3K) inhibitor, wortmannin, but not the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor, PD98059. This suggests that SCF is involved in sorafenib-induced MC maturation. In addition, the compensatory upregulation of PI3K-signaling from inhibition of MAPK signaling by sorafenib might stimulate MC maturation in situ. We also evaluated MCs within the skin samples from patients with drug eruptions by sorafenib administration. The total and degranuated MCs number as well as SCF expression was significantly increased compared to healthy individuals.

CONCLUSION

Our results contribute to a better understanding of the mechanism by which sorafenib induces adverse cutaneous reactions via activation of skin-type MC degranulation and maturation. This activation appears to be related to PI3K signaling and SCF production, which could be a new targets for treating sorafenib-induced adverse reactions.

Recent advance in the pharmacogenomics of human Solute Carrier Transporters (SLCs) in drug disposition

Drug pharmacokinetics is influenced by the function of metabolising enzymes and influx/efflux transporters. Genetic variability of these genes is known to impact on clinical therapies. Solute Carrier Transporters (SLCs) are the primary influx transporters responsible for the cellular uptake of drug molecules, which consequently, impact on drug efficacy and toxicity. The Organic Anion Transporting Polypeptides (OATPs), Organic Anion Transporters (OATs) and Organic Cation Transporters (OCTs/OCTNs) are the most important SLCs involved in drug disposition. The information regarding the influence of SLC polymorphisms on drug pharmacokinetics is limited and remains a hot topic of pharmaceutical research. This review summarises the recent advance in the pharmacogenomics of SLCs with an emphasis on human OATPs, OATs and OCTs/OCTNs. Our current appreciation of the degree of variability in these transporters may contribute to better understanding the inter-patient variation of therapies and thus, guide the optimisation of clinical treatments.

Involvement of the Transporters P-Glycoprotein and Breast Cancer Resistance Protein in Dermal Distribution of the Multikinase Inhibitor Regorafenib and Its Active Metabolites

Regorafenib is a multikinase inhibitor orally administered to colorectal cancer patients, and is known to often exhibit dermal toxicity. The purpose of this study is to clarify possible involvement of P-glycoprotein and breast cancer resistance protein (BCRP) in the dermal accumulation of regorafenib and its active metabolites M-2 and M-5. Following intravenous administration in triple knockout (Abcb1a/1b/bcrp^-/-; TKO) and wild-type (WT) mice, delayed plasma clearance of M-2 and M-5, but not regorafenib, was observed in TKO mice compared to WT mice. Elacridar, an inhibitor of both transporters, also caused delayed clearance of M-2 and M-5, suggesting that these transporters are involved in their elimination. Skin-to-plasma concentration ratios of regorafenib, M-2, and M-5 were significantly higher in TKO mice than in WT mice. Elacridar increased skin-to-plasma and epidermis-to-plasma concentration ratios of regorafenib. Basal-to-apical transport of M-2 and M-5 was observed in LLC-PK1-Pgp and MDCKII/BCRP/PDZK1 cells, which was inhibited by elacridar and the BCRP inhibitor Ko143, respectively. The present findings thus indicate that P-glycoprotein and BCRP are involved in the accumulation of regorafenib and its active metabolites in the skin, by affecting either their systemic exposure or their plasma distribution in the circulating blood.

Trafficking and other regulatory mechanisms for organic anion transporting polypeptides and organic anion transporters that modulate cellular drug and xenobiotic influx and that are dysregulated in disease

Organic anion transporters (OATs) and organic anion-transporting polypeptides (OATPs), encoded by a number of solute carrier (SLC)22A and SLC organic anion (SLCO) genes, mediate the absorption and distribution of drugs and other xenobiotics. The regulation of OATs and OATPs is complex, comprising both transcriptional and post-translational mechanisms. Plasma membrane expression is required for cellular substrate influx by OATs/OATPs. Thus, interest in post-translational regulatory processes, including membrane targeting, endocytosis, recycling and degradation of transporter proteins, is increasing because these are critical for plasma membrane expression. After being synthesized, transporters undergo N-glycosylation in the endoplasmic reticulum and Golgi apparatus and are delivered to the plasma membrane by vesicular transport. Their expression at the cell surface is maintained by de novo synthesis and recycling, which occurs after clathrin- and/or caveolin-dependent endocytosis of existing protein. Several studies have shown that phosphorylation by signalling kinases is important for the internalization and recycling processes, although the transporter protein does not appear to be directly phosphorylated. After internalization, transporters that are targeted for degradation undergo ubiquitination, most likely on intracellular loop residues. Epigenetic mechanisms, including methylation of gene regulatory regions and transcription from alternate promoters, are also significant in the regulation of certain SLC22A/SLCO genes. The membrane expression of OATs/OATPs is dysregulated in disease, which affects drug efficacy and detoxification. Several transporters are expressed in the cytoplasmic subcompartment in disease states, which suggests that membrane targeting/internalization/recycling may be impaired. This article focuses on recent developments in OAT and OATP regulation, their dysregulation in disease and the significance for drug therapy.

Impact of Membrane Drug Transporters on Resistance to Small-Molecule Tyrosine Kinase Inhibitors

Small-molecule inhibitors of tyrosine kinases (TKIs) are the mainstay of treatment for many malignancies and represent novel treatment options for other diseases such as idiopathic pulmonary fibrosis. Twenty-five TKIs are currently FDA-approved and >130 are being evaluated in clinical trials. Increasing evidence suggests that drug exposure of TKIs may significantly contribute to drug resistance, independently from somatic variation of TKI target genes. Membrane transport proteins may limit the amount of TKI reaching the target cells. This review highlights current knowledge on the basic and clinical pharmacology of membrane transporters involved in TKI disposition and their contribution to drug efficacy and adverse drug effects. In addition to non-genetic and epigenetic factors, genetic variants, particularly rare ones, in transporter genes are promising novel factors to explain interindividual variability in the response to TKI therapy.

Systematic Analysis of Quantitative Logic Model Ensembles Predicts Drug Combination Effects on Cell Signaling Networks

A major challenge in developing anticancer therapies is determining the efficacies of drugs and their combinations in physiologically relevant microenvironments. We describe here our application of “constrained fuzzy logic” (CFL) ensemble modeling of the intracellular signaling network for predicting inhibitor treatments that reduce the phospho‐levels of key transcription factors downstream of growth factors and inflammatory cytokines representative of hepatocellular carcinoma (HCC) microenvironments. We observed that the CFL models successfully predicted the effects of several kinase inhibitor combinations. Furthermore, the ensemble predictions revealed ambiguous predictions that could be traced to a specific structural feature of these models, which we resolved with dedicated experiments, finding that IL‐1α activates downstream signals through TAK1 and not MEKK1 in HepG2 cells. We conclude that CFL‐Q2LM (Querying Quantitative Logic Models) is a promising approach for predicting effective anticancer drug combinations in cancer‐relevant microenvironments.

Loss of SLCO1B3 drives taxane resistance in prostate cancer

BACKGROUND

Both taxanes, docetaxel and cabazitaxel, are effective treatments for metastatic castration-resistant prostate cancer (mCRPC). However, resistance to taxanes is common. Our objective was to investigate mechanisms of taxane resistance in prostate cancer.

METHODS

Two docetaxel-resistant patient-derived xenografts (PDXs) of CRPC were established (PC339-DOC and PC346C-DOC) in male athymic nude mice by frequent intraperitoneal administrations of docetaxel. Next-generation sequencing was performed on PDX tissue pre- and post-docetaxel resistance and gene expression profiles were compared. [(14)C]-docetaxel and [(14)C]-cabazitaxel uptake assays in vitro and cytotoxicity assays were performed to validate direct involvement of transporter genes in taxane sensitivity.

RESULTS

Organic anion-transporting polypeptide (SLCO1B3), an influx transporter of docetaxel, was significantly downregulated in PC346C-DOC tumours. In accordance with this finding, intratumoural concentrations of docetaxel and cabazitaxel were significantly decreased in PC346C-DOC as compared with levels in chemotherapy-naive PC346C tumours. In addition, silencing of SLCO1B3 in chemo-naive PC346C resulted in a two-fold decrease in intracellular concentrations of both taxanes. Overexpression of SLCO1B3 showed higher sensitivity to docetaxel and cabazitaxel.

CONCLUSIONS

The SLCO1B3 determines intracellular concentrations of docetaxel and cabazitaxel and consequently influences taxane efficacy. Loss of the drug transporter SLCO1B3 may drive taxane resistance in prostate cancer.

Multikinase Inhibitor-Induced Hand-Foot Skin Reaction: A Review of Clinical Presentation, Pathogenesis, and Management

Multikinase inhibitors (MKIs) are targeted cancer therapies designed to inhibit multiple tyrosine kinase pathways responsible for tumor proliferation, growth, and survival. These agents are more able to target cancer cells and possess better safety profiles than conventional chemotherapies. However, MKIs can produce significant cutaneous adverse events, hand-foot skin reaction (HFSR) being the most clinically significant. Although not life threatening, HFSR can lead to MKI dose modification, interruption, or termination, potentially limiting the anti-tumor effect. This article summarizes the current knowledge concerning the epidemiology, clinical presentation, pathogenesis, histopathology, prognostic implication, and current evidence-based prophylactic and reactive treatment options for MKI-induced HFSR. Its high incidence and significant impact on the quality of life emphasizes the great need to understand the pathogenesis and improve management of this condition.

Patient-Level Adverse Event Patterns in a Single-Institution Study of the Multi-Kinase Inhibitor Sorafenib

Novel characterization of patterns of adverse events (AEs) of kinase inhibitors (KIs) could reveal new insights on human molecular physiology and methods to improve the therapeutic index of KIs. Incidence and severity of AEs for each of 157 patients enrolled in sorafenib clinical trials were determined for three clinically relevant treatment intervals: weeks 0–3, weeks 3–7, and after 7 weeks. The most common within patient co‐occurrences were mucositis with dermatologic events: hand‐foot syndrome (HFS; odds ratio [OR] = 4.36; p = 0.0017) and rash (OR = 5.32; p < 0.001). Prevalence of severe: alopecia (p = 0.02), diarrhea (p < 0.001), and fatigue (p = 0.005) increased over the course of therapy. Incidence of HFS (60%) and diarrhea (25%) increased up to a minimum steady‐state concentration (approximately 5 mcg mL^‐1) and plateaued thereafter. Common AEs of sorafenib occur in distinct temporal and tissue distribution patterns and this analysis identified unrecognized relationships among mechanism‐dependent and independent effects of a KI.