Tyrosine Kinase Research Articles

Ocular surface adverse reactions of antitumor-targeted drugs

With the extensive application of targeted drugs, the survival rate of cancer patients has been significantly improved. However, adverse reactions to the drugs have also become apparent, especially those affecting the ocular surface, which can severely impact patients' vision and quality of life. The article systematically analyzes a variety of targeted drugs, including epidermal growth factor receptor inhibitors, human epidermal growth factor receptor 2 inhibitors, fibroblast growth factor receptor inhibitors, selective estrogen receptor modulators, vascular endothelial growth factor receptor inhibitors, aromatase inhibitors, proteasome inhibitors, antibody-drug conjugates, Bruton's tyrosine kinase inhibitors, FMS-like tyrosine kinase 3 inhibitors, and cyclin-dependent kinase inhibitors, and discusses their adverse reactions on the ocular surface. The review emphasizes the role of clinicians in monitoring and managing patients' ocular surface health and the importance of early diagnosis and intervention to ensure that patients receive optimal visual protection while undergoing antitumor treatment.

Tyrosine-protein kinase SYK-related gene signature in baseline immune cells associated with adjuvant immunotherapy-induced immune-related adverse events in melanoma.

Immune checkpoint inhibition (ICI) shows benefits in adjuvant (AT) and neoadjuvant (NAT) melanoma treatments. However, ICI frequently induces severe immune-related adverse events (irAEs). Unlike metastatic disease, where irAEs are a clinical trade-off for treatment that improves survival, the toxicity burden from ICI in AT is a substantial clinical problem urging for irAE-predictive biomarkers. We assessed post-surgical, pre-ICI treatment peripheral CD4+ and CD8+ T cells from clinical trial patients (CheckMate-915) treated with AT nivolumab (NIVO, n=130) or ipilimumab/nivolumab (COMBO, n=82). Performing RNA-seq differential gene expression analysis we tested baseline differences associated with severe (grade 3-5) irAEs and constructed an irAE-predictive model using LASSO-regularized logistic regression. The analysis of predicted protein-protein interactions among differentially expressed genes (DEGs) in peripheral CD4+ cells revealed significant enrichment of the spleen tyrosine kinase (SYK) pathway, associated with severe irAEs in COMBO-treated patients. This gene-expression signature predicted severe-irAE COMBO patients (chi-square p-value=0.001) with 73% accuracy and was independent of disease recurrence (p=0.79). The irAE-predictive model incorporating this gene-expression signature demonstrated 82% accuracy (chi-square p-value=8.91E-06). We identified baseline gene-expression differences in key immune pathways of peripheral blood T cells from COMBO-treated patients with grade 3-5 irAEs, and defined a SYK-related gene signature correctly identifying ~60% of COMBO-treated patients with grade 3-5 irAE. This finding aligns with our previous work linking anti-CTLA-4 irAEs with a germline variant associated with high SYK expression. This gene signature may serve as a baseline biomarker of severe grade 3-5 irAE risk, which is especially important in AT.

Complete response in a lung adenocarcinoma with pleural metastases initially treated with gefitinib and switched to osimertinib after cerebral oligo-progression with unknown T790M mutation: a case report and review of literature

BackgroundFirst- and second-generation anti-epithelial growth factor receptor tyrosine kinase inhibitors have shown great efficacy in the treatment of advanced adenocarcinoma with epithelial growth factor receptor mutations, but this efficacy is limited by certain resistance mechanisms, in particular the T790M mutation, which must be screened before second-line treatment with osimertinib is indicated. The search for this mutation is sometimes difficult, especially in cases of intracranial relapse, through this case report we attempt to discuss the possibility of initiating treatment with osimertinib despite an unknown T790M mutation in such situation.Case reportWe present the case of a 70-year-old Moroccan male patient diagnosed with non-small cell lung carcinoma initially metastatic to the pleura with an epithelial growth factor receptor mutation who received gefitinib in first line with a complete response, he subsequently presented with cerebral oligo-progression with extra cranial stability. The patient was started on osimertinib with unknown T790M status, as it was impossible to perform a cerebral biopsy, the evolution was characterized by a partial response followed by stereotactic radiotherapy then a complete response for 2 years.ConclusionWe can discuss osimertinib as an option for patients with stage IV non-small cell lung cancer with brain oligo-progression on prior tyrosine kinase inhibitors and unknown T790M status, further studies are needed in this area.

Multi-omics and pharmacological characterization of patient-derived glioma cell lines

Glioblastoma (GBM) is the most common brain tumor and remains incurable. Primary GBM cultures are widely used tools for drug screening, but there is a lack of genomic and pharmacological characterization for these primary GBM cultures. Here, we collect 50 patient-derived glioma cell (PDGC) lines and characterize them by whole genome sequencing, RNA sequencing, and drug response screening. We identify three molecular subtypes among PDGCs: mesenchymal (MES), proneural (PN), and oxidative phosphorylation (OXPHOS). Drug response profiling reveals that PN subtype PDGCs are sensitive to tyrosine kinase inhibitors, whereas OXPHOS subtype PDGCs are sensitive to histone deacetylase inhibitors, oxidative phosphorylation inhibitors, and HMG-CoA reductase inhibitors. PN and OXPHOS subtype PDGCs stably form tumors in vivo upon intracranial transplantation into immunodeficient mice, whereas most MES subtype PDGCs fail to form tumors in vivo. In addition, PDGCs cultured by serum-free medium, especially long-passage PDGCs, carry MYC/MYCN amplification, which is rare in GBM patients. Our study provides a valuable resource for understanding primary glioma cell cultures and clinical translation and highlights the problems of serum-free PDGC culture systems that cannot be ignored.

Bilateral Hemorrhagic Occlusive Retinal Vasculitis Induced by Osimertinib in a Patient with Non-Small Cell Lung Cancer.

To report a case of bilateral retinal vasculitis in a patient with non-small cell lung cancer undergoing treatment with osimertinib. A 58-year-old woman with lung adenocarcinoma (T4N3M1a stage IV) presented with blurry vision in both eyes (OU). Eighteen months before symptom onset, the treatment was changed from afatinib (20 mg/day) to osimertinib (80 mg/day) because of tumor progression. The visual acuity was 20/30 and 20/25 in the right and left eyes, respectively. Clinical examination revealed few anterior chamber cells, 2+ vitreous cells, haze, and multiple retinal hemorrhages in the peripheral retinas (OU). Fluorescein angiography revealed retinal vasculitis with a severely non-perfused area in the periphery. These findings indicated hemorrhagic occlusive retinal vasculitis (HORV). Osimertinib was reduced to 40 mg/day, and oral prednisolone was started at 30 mg/day. This improved retinal vasculitis; however, the ischemic area did not improve. Pan-retinal photocoagulation was performed while tapering the oral prednisolone to 10 mg/day. Although macular edema (ME) occasionally occurred (OU), systemic and local treatment with steroid-stabilized HORV and ME helped increase the dose of osimertinib to 80 mg/day without cancer progression for 18 months. Her visual acuity remained 10/20 (OU). Osimertinib, a third-generation tyrosine kinase inhibitor, can be used to treat advanced non-small cell lung cancer with epidermal growth factor receptor mutation-induced bilateral HORV. This adverse effect can be managed with systemic and local steroid treatment and continued osimertinib administration.

CADD Methods for Developing Novel Compounds Synthesized to Inhibit Tyrosine Kinase Receptors.

Growth factors and their receptor tyrosine kinases play a central role in regulating vital cellular processes such as proliferation, differentiation, division, and cell survival, and they are closely associated with the development of various types of cancer, particularly in the context of angiogenesis. Although several small chemical compounds targeting tyrosine kinase receptors have been approved by the FDA for cancer treatment by inhibiting angiogenesis, there is still a need for more effective medications. in silico studies are now crucial tools for the design of new drugs, offering considerable advantages such as cost and time reduction. In this review, we examined recent in silico research carried out between 2022 and 2024, focusing on new drug candidates synthesized to fight cancer, in particular by targeting tyrosine kinase receptors involved in the process of angiogenesis.

In vivo Bruton's tyrosine kinase inhibition attenuates alcohol-associated liver disease by regulating CD84-mediated granulopoiesis.

Severe alcohol-associated hepatitis (AH) is a life-threatening form of alcohol-associated liver disease. Liver neutrophil infiltration is a hallmark of AH, yet the effects of alcohol on neutrophil functions remain elusive. Identifying therapeutic targets to reduce neutrophil-mediated liver damage is essential. Bruton's tyrosine kinase (BTK) plays an important role in neutrophil development and function; however, the role of BTK in AH is unknown. Using RNA sequencing of circulating neutrophils, we found an increase in Btk expression (P = 0.05) and phosphorylated BTK (pBTK) in patients with AH compared with healthy controls. In vitro, physiologically relevant doses of alcohol resulted in a rapid, TLR4-mediated induction of pBTK in neutrophils. In a preclinical model of AH, administration of a small-molecule BTK inhibitor (evobrutinib) or myeloid-specific Btk knockout decreased proinflammatory cytokines and attenuated neutrophil-mediated liver damage. We found that pBTK was essential for alcohol-induced bone marrow granulopoiesis and liver neutrophil infiltration. In vivo, BTK inhibition or myeloid-specific Btk knockout reduced granulopoiesis, circulating neutrophils, liver neutrophil infiltration, and liver damage in a mouse model of AH. Mechanistically, using liquid chromatography-tandem mass spectrometry, we identified CD84 as a kinase target of BTK, which is involved in granulopoiesis. In vitro, CD84 promoted alcohol-induced interleukin-1β and tumor necrosis factor-α in primary human neutrophils, which was inhibited by CD84-blocking antibody treatment. Our findings define the role of BTK and CD84 in regulating neutrophil inflammation and granulopoiesis, with potential therapeutic implications in AH.

The Pharmacokinetics, Metabolism, and Clearance Mechanisms of Ritlecitinib, a Janus Kinase 3 and Tyrosine-Protein Kinase Family Inhibitor, in Humans.

Ritlecitinib is an oral once-daily irreversible inhibitor of Janus kinase 3 and tyrosine-protein kinase family being developed for the treatment of moderate-to-severe alopecia areata. This study examined the disposition of ritlecitinib in male participants following oral and intravenous administration using accelerator mass spectroscopy methodology to estimate pharmacokinetic parameters and characterize metabolite profiles. The results indicated ritlecitinib had a systemic clearance of 43.7 L/h, a steady state volume of distribution of 73.8 L, extent of absorption of 89%, time to maximum plasma concentration of ~0.5 hour, and absolute oral bioavailability of 64%. An observed long terminal half-life of total radioactivity was primarily attributed to ritlecitinib binding to plasma albumin. Ritlecitinib was the main circulating drug species in plasma (~30%) with one major pharmacologically inactive cysteine conjugated metabolite (M2) at >10%. Oxidative metabolism (fractional clearance 0.47) and glutathione related conjugation (fractional clearance 0.24) were the primary routes of elimination for ritlecitinib with the greatest disposition of radioactivity shown in the urine (~71%). In vitro phenotyping indicated ritlecitinib cytochrome P450 fraction of metabolism assignments of 0.29 for CYP3A, 0.09 for CYP2C8, 0.07 for CYP1A2, and 0.02 for CYP2C9. In vitro phenotyping in recombinant human glutathione S-transferases indicated ritlecitinib was turned over by a number of cytosolic and microsomal enzyme isoforms. Significance Statement This study provides a detailed understanding of the disposition and metabolism of ritlecitinib, a JAK3 and TEC family kinase inhibitor for alopecia areata, in humans, as well as characterization of clearance pathways and PK of ritlecitinib and its metabolites. As an AMS-based ADME study design, we have expanded on reporting the standard ADME endpoints, providing key pharmacokinetic parameters like clearance, volume of distribution and bioavailability allowing for a more comprehensive understanding of drug disposition.

Combination therapy consisting of transarterial chemoembolization, lenvatinib, and programmed cell death protein 1 blockade for hepatocellular carcinoma with inferior vena cava tumor thrombus: a case series study and literature review.

Patients with hepatocellular carcinoma (HCC) and inferior vena cava carcinoma tumor thrombus (IVCTT) have poor prognosis. Combination therapy involving blockade of programmed cell death protein 1 (PD-1) and tyrosine kinase inhibitors (TKIs) is an efficient treatment strategy for advanced HCC. However, surgical treatment after a combination of systemic therapy and transarterial chemoembolization (TACE) for HCC with IVCTT has not been widely reported, and the efficacy and safety of this treatment have not been studied. In the 21 cases reported herein, the patients were treated with TACE, lenvatinib, and PD-1 blockade. The treatment responses, progression-free survival (PFS), overall survival (OS), disease control rate, and toxicities were evaluated, and the related literature was reviewed. The overall response and disease control rates were 66.7% and 85.7%, respectively. The median PFS time was 16.0 months, with a 1-year PFS rate of 55.60%. The median OS was not reached, with a 1-year OS rate of 66.70%. Four patients underwent hepatectomy without serious complications and survived for 29.1, 24.7, 14.2, and 13.8 months. Three patients survived tumor-free, and one patient experienced intrahepatic recurrence. Pathological complete response and major pathological responses were observed in one and three patients, respectively. Treatment-related adverse events of any grade occurred in of 8/9 patients (88.9%), and grade 3 treatment-related adverse events occurred in one patient. The combination of TACE, lenvatinib, and PD-1 is effective for HCC with IVCTT and has acceptable adverse effects.

Comparative analysis of dual immune checkpoint inhibitor combination therapy versus immune checkpoint inhibitor plus tyrosine kinase inhibitor combination therapy for renal cell carcinoma with inferior vena cava tumor thrombosis.

Whether immune checkpoint inhibitor (ICI) plus ICI combination therapy or ICI plus tyrosine kinase inhibitor (TKI) combination therapy is useful for renal cell carcinoma (RCC) with inferior vena cava tumor thrombosis (IVCTT) remains unclear. We retrospectively evaluated the therapeutic effects and incidence of treatment-related adverse events (TRAEs) associated with ICI-based combination therapy in 36 patients with advanced RCC with IVCTT. The median age at initiation of treatment was 71years; the IVCTT stages were cT3b in 22 patients and cT3c in 14. The ICI-ICI and ICI-TKI groups comprised 15 and 21 patients, respectively. Median tumor shrinkage at the best response showed that the primary tumor diameter decreased by 1.8cm (22%), and the IVCTT height decreased by 1.5cm (26%). A higher proportion of patients in the ICI-TKI group experienced tumor shrinkage than those in the ICI-ICI group (primary tumor, p = 0.0325; IVCTT, p = 0.0112). Approximately 27% of patients experienced an increase in the IVCTT height with ICI-ICI combination therapy. No significant difference was observed in the relative tumor shrinkage of IVCTT, primary or level-down staging of IVCTT, other treatment effects, incidence of TRAEs, surgical outcomes, or prognosis between the groups. ICI-based combination therapy is effective against IVCTT and primary RCC. Although ICI-ICI is associated with a higher probability of tumor growth compared with ICI-TKI in the frequency of tumor regression, both therapies may be almost equally effective against primary RCC with IVCTT.

Mechanisms and treatment of pulmonary arterial hypertension.

Substantial progress has been made in the management of pulmonary arterial hypertension (PAH) in the past 25 years, but the disease remains life-limiting. Established therapies for PAH are mostly limited to symptomatic relief by correcting the imbalance of vasoactive factors. The tyrosine kinase inhibitor imatinib, the first predominantly non-vasodilatory drug to be tested in patients with PAH, improved exercise capacity and pulmonary haemodynamics compared with placebo but at the expense of adverse events such as subdural haematoma. Given that administration by inhalation might reduce the risk of systemic adverse effects, inhaled formulations of tyrosine kinase inhibitors are currently in clinical development. Other novel therapeutic approaches for PAH include suppression of activin receptor type IIA signalling with sotatercept, which has shown substantial efficacy in clinical trials and was approved for use in the USA in 2024, but the long-term safety of the drug remains unclear. Future advances in the management of PAH will focus on right ventricular function and involve deep phenotyping and the development of a personalized medicine approach. In this Review, we summarize the mechanisms underlying PAH, provide an overview of available PAH therapies and their limitations, describe the development of newer, predominantly non-vasodilatory drugs that are currently being tested in phase II or III clinical trials, and discuss future directions for PAH research.

Human Leukocyte Antigen-DR and Cluster Designation 34: Double-negative Acute Myeloid Leukemias – Our Experience in Clinical Setting

Abstract Introduction: Dual negativity for cluster designation (CD) 34 and human leukocyte antigen (HLA)-DR antigen in leukemia panel is an important finding in clinical practice. The combination of this finding though seen classically in acute promyelocytic leukemia (APL) is not specific to it but can be seen in many other myeloid leukemias like the ones associated with nucleophosmin 1 (NPM1) or FMS-related tyrosine kinase 3 gene-internal tandem duplication (FLT3-ITD) abnormalities. It is important to identify APL from non-APL leukemia as treatment and prognosis vary. Aims and Objectives: We analyzed CD 34 and HLA-DR dual-negative acute myeloid leukemia (AML) cases presented to us over 2.5 years (26 cases) and segregated them into APL and non-APL groups to study their morphological/flow cytometric and cytogenetic profile and correlation with treatment response. Materials and Methods: It was a prospective study including all newly diagnosed AMLs showing CD 34 and HLA-DR dual negativity in flow cytometry profile. Cases in which complete information/cytogenetics/molecular profile were not available, were excluded from the study. The patients were followed up till the end of induction to look for morphological response to induction therapy. The clinical and treatment records were pulled out from the patient database after ethical committee clearance. Results: A total of 139 new AML cases were encountered during the study period out of which 28 (20%) were found to be dual negative for CD34 and HLA-DR. The non-APL group showed higher mean age, TLC at baseline, variable morphology, and more number of aberrant expression on flow cytometry profile. No significant difference was noted in terms of gender, presence of hepatosplenomegaly, DIC as complication, or percentage of blasts/blasts equivalent at baseline. Our study found that while all APL patients had PML-RARA, the associated molecular abnormalities were much lesser as compared to the non-APL group which showed a variety of abnormalities such as NPM1, FLT3, RAS mutation, and mutations involving epigenetic modifiers. The response rate to induction therapy was significantly lower in the non-APL group as compared to the APL group. Conclusion: The non-APL myeloid leukemia which is dual negative is commonly found to be associated with cup-shaped morphology, NPM, or FLT3-ITD mutation along with other abnormalities. These patients were older in age, showed higher TLC and higher blast counts, associated with poorer response to induction therapy as compared to the APL group.

Concomitant targeting of FLT3 and SPHK1 exerts synergistic cytotoxicity in FLT3-ITD+ acute myeloid leukemia by inhibiting β-catenin activity via the PP2A-GSK3β axis

BackgroundApproximately 25–30% of patients with acute myeloid leukemia (AML) have FMS-like receptor tyrosine kinase-3 (FLT3) mutations that contribute to disease progression and poor prognosis. Prolonged exposure to FLT3 tyrosine kinase inhibitors (TKIs) often results in limited clinical responses due to diverse compensatory survival signals. Therefore, there is an urgent need to elucidate the mechanisms underlying FLT3 TKI resistance. Dysregulated sphingolipid metabolism frequently contributes to cancer progression and a poor therapeutic response. However, its relationship with TKI sensitivity in FLT3-mutated AML remains unknown. Thus, we aimed to assess mechanisms of FLT3 TKI resistance in AML.MethodsWe performed lipidomics profiling, RNA-seq, qRT-PCR, and enzyme-linked immunosorbent assays to determine potential drivers of sorafenib resistance. FLT3 signaling was inhibited by sorafenib or quizartinib, and SPHK1 was inhibited by using an antagonist or via knockdown. Cell growth and apoptosis were assessed in FLT3-mutated and wild-type AML cell lines via Cell counting kit-8, PI staining, and Annexin-V/7AAD assays. Western blotting and immunofluorescence assays were employed to explore the underlying molecular mechanisms through rescue experiments using SPHK1 overexpression and exogenous S1P, as well as inhibitors of S1P2, β-catenin, PP2A, and GSK3β. Xenograft murine model, patient samples, and publicly available data were analyzed to corroborate our in vitro results.ResultsWe demonstrate that long-term sorafenib treatment upregulates SPHK1/sphingosine-1-phosphate (S1P) signaling, which in turn positively modulates β-catenin signaling to counteract TKI-mediated suppression of FLT3-mutated AML cells via the S1P2 receptor. Genetic or pharmacological inhibition of SPHK1 potently enhanced the TKI-mediated inhibition of proliferation and apoptosis induction in FLT3-mutated AML cells in vitro. SPHK1 knockdown enhanced sorafenib efficacy and improved survival of AML-xenografted mice. Mechanistically, targeting the SPHK1/S1P/S1P2 signaling synergizes with FLT3 TKIs to inhibit β-catenin activity by activating the protein phosphatase 2 A (PP2A)-glycogen synthase kinase 3β (GSK3β) pathway.ConclusionsThese findings establish the sphingolipid metabolic enzyme SPHK1 as a regulator of TKI sensitivity and suggest that combining SPHK1 inhibition with TKIs could be an effective approach for treating FLT3-mutated AML.

TG-IGF1R: A Novel Receptor Tyrosine Kinase Fusion Oncogene in Pediatric Thyroid Cancer.

Receptor Tyrosine Kinase (RTK) fusions of RET, NTRK1/3, and ALK are enriched among pediatric thyroid cancer patients with metastatic and persistent disease and their oncoproteins represent attractive drug targets. We performed RNA-sequencing in a papillary thyroid cancer lacking other frequent driver alterations. We report a novel RTK fusion, TG-IGF1R, in a 17-year-old female patient with angioinvasive follicular variant papillary thyroid cancer. The in-frame fusion protein preserves the cholinesterase-like domain of TG with dimerization properties and the transmembrane and kinase domain of IGF1R. The tumor sample shows increased IGF1R mRNA expression and tyrosine kinase phosphorylation, augmentation of MAPK transcriptional output genes and decreased NIS levels. We reveal a novel targetable kinase fusion oncogene in thyroid cancer which is not incorporated in different thyroid-specific sequencing panels. The integration of IGF1R fusion screening in the next versions of thyroid-specific targeted NGS panels may be beneficial to thyroid cancer patients.

Regorafenib-related erythrocytosis in metastatic extra-gastrointestinal stromal tumor: a case report

IntroductionRegorafenib is an oral multi-targeted tyrosine kinase inhibitor (TKI) indicated for the treatment of various tumor types, including metastatic gastrointestinal stromal tumors (GIST), as a third-line systemic therapy. Erythrocytosis, which is characterized by an increase in erythrocyte count, hemoglobin, and hematocrit levels, has been described as a side effect of some antiangiogenic TKIs but has never been associated with regorafenib administration.Case presentationAn extra-GIST was diagnosed in a 58-year-old woman after she underwent surgery to remove a pelvic mass. Three years later, systemic therapy with imatinib was started due to pelvic disease recurrence. However, after six months, due to disease progression, we prescribed sunitinib, which the patient received for four years. Regorafenib was initiated in June 2019, and after six months, we noted an increase in the erythrocytes’ count and hemoglobin (Hb) levels. Given that the patient had clinical benefit and hematocrit was within normal range, we only monitored the blood cell count and continued to give regorafenib at the same dose. The drug was then stopped for over six weeks due to hospitalization for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and Hb levels returned to normal. Therefore, we decided to restart regorafenib at a lower dose. However, Hb levels rose again in conjunction with increased hematocrit, resulting in the need for multiple phlebotomies. We attempted to restart regorafenib every other day, but it was unsuccessful, so we stopped it permanently in May 2023, and all values returned to normal.ConclusionRegorafenib may cause secondary erythrocytosis that could not be dose-related, as this case report suggests. Secondary erythrocytosis might be a marker of TKI efficacy, given the patient’s prolonged clinical benefit during regorafenib treatment (48 months). In patients receiving regorafenib, monitoring blood count as well as any symptoms associated with erythrocytosis may be suggested.

Enhanced anti-tumor effects by combination of tucatinib and radiation in HER2-overexpressing human cancer cell lines

BackgroundTucatinib (TUC), a HER2-directed tyrosine kinase inhibitor, is the first targeted drug demonstrating intracranial efficacy and significantly prolonged survival in metastatic HER2-positive breast cancer (BC) patients with brain metastases. Current treatments for brain metastases often include radiotherapy, but little is known about the effects of combination treatment with TUC. Therefore, we examined the combined effects of irradiation and TUC in human HER2-overexpressing BC, non-small cell lung cancer (NSCLC), and colorectal cancer (CRC) cell lines. For the latter two, a standard therapy successfully targeting HER2 is yet to be established.MethodsNine HER2-overexpressing (BC: BT474, ZR7530, HCC1954; CRC: LS411N, DLD1, COLO201; NSCLC: DV90, NCI-H1781) and three control cell lines (BC: MCF7, HCC38; NSCLC: NCI-H2030) were examined. WST-1 assay (metabolic activity), BrdU ELISA (proliferation), γH2AX assay (DNA double-strand breaks (DSB), Annexin V assay (apoptosis), and clonogenic assay (clonogenicity) were performed after treatment with TUC and/or irradiation (IR). The relevance of the treatment sequence was analyzed exemplarily.ResultsIn BC, combinatorial treatment with TUC and IR significantly decreased metabolic activity, cell proliferation, clonogenicity and enhanced apoptotis compared to IR alone, whereby cell line-specific differences occurred. In the PI3KCA-mutated HCC1954 cell line, addition of alpelisib (ALP) further decreased clonogenicity. TUC delayed the repair of IR-induced DNA damage but did not induce DSB itself. Investigation of treatment sequence indicated a benefit of IR before TUC versus IR after TUC. Also in CRC and NSCLC, the combination led to a stronger inhibition of metabolic activity, proliferation, and clonogenic survival (only in NSCLC) than IR alone, whereby about 10-fold higher concentrations of TUC had to be applied than in BC to induce significant changes.ConclusionOur data indicate that combination of TUC and IR could be more effective than single treatment strategies for BC. Thereby, treatment sequence seems to be an important factor. The lower sensitivity to TUC in NSCLC and particularly in CRC (compared to BC) implicates, that tumor promotion there might be less HER2-related. Combination with inhibitors of other driver mutations may aid in overcoming partial TUC resistance. These findings are of high relevance to improve long-time prognosis especially in brain-metastasized situations given the intracranial activity of TUC.

Early-Stage Non-Small Cell Lung Cancer: New Challenges with Immune Checkpoint Blockers and Targeted Therapies

The recent advent of tyrosine kinase inhibitors (TKIs) and immune checkpoint blockers (ICBs) in early-stage non-small cell lung cancer (NSCLC) has dramatically modified treatment strategies by improving the prognosis in this setting. Osimertinib and alectinib, both TKIs, have shown significant improvements in outcomes for patients with resected EGFR- and ALK-positive NSCLC, respectively, changing the standard of care in these subgroups. More recently, the LAURA trial showed the efficacy of osimertinib after chemoradiotherapy in patients with unresectable stage III NSCLC harboring EGFR mutations. Numerous trials are still ongoing to investigate neoadjuvant/perioperative TKIs in several oncogene-driven NSCLC. In addition, several ICBs have been tested and approved as adjuvant (atezolizumab and pembrolizumab), neoadjuvant (nivolumab), and perioperative treatments (pembrolizumab) for patients with resectable early-stage NSCLC. Despite these advances, many challenges remain regarding the use of TKIs and ICBs in this setting, including the optimal duration of adjuvant TKI or induction ICB therapy, the role of minimal residual disease to identify patients at high-risk of disease relapse and to guide adjuvant treatment decisions, and the role of adjuvant chemotherapy in resected oncogene-driven NSCLC. Furthermore, potential predictive biomarkers for efficacy are needed to eventually intensify the entire perioperative strategies. This review aims to summarize and discuss the available evidence, the ongoing trials, and the challenges associated with TKI- and ICB-based approaches in early-stage NSCLC.

Inhibition of Tumoral VISTA to Overcome TKI Resistance via Downregulation of the AKT/mTOR and JAK2/STAT5 Pathways in CML.

Tyrosine kinase inhibitors (TKIs) have revolutionized the treatment landscape for chronic myeloid leukemia (CML). However, TKI resistance poses a significant challenge, leading to treatment failure and disease progression. Resistance mechanisms include both BCR::ABL1-dependent and BCR::ABL1-independent pathways. The mechanisms underlying BCR::ABL1 independence remain incompletely understood, with CML cells potentially activating alternative signaling pathways, including the AKT/mTOR and JAK2/STAT5 pathways, to compensate for the loss of BCR::ABL1 kinase activity. This study explored tumoral VISTA (encoded by VSIR) as a contributing factor to TKI resistance in CML patients and identified elevated tumoral VISTA levels as a marker of resistance and poor survival. Through in vitro and in vivo analyses, we demonstrated that VSIR knockdown and the application of NSC-622608, a novel VISTA inhibitor, significantly impeded CML cell proliferation and induced apoptosis by attenuating the AKT/ mTOR and JAK2/STAT5 pathways, which are crucial for CML cell survival independent of BCR::ABL1 kinase activity. Moreover, VSIR overexpression promoted TKI resistance in CML cells. Importantly, the synergistic effect of NSC-622608 with TKIs offers a potent therapeutic avenue against both imatinib-sensitive and imatinib-resistant CML cells, including those harboring the challenging T315I mutation. Our findings highlight the role of tumoral VISTA in mediating TKI resistance in CML, suggesting that inhibition of VISTA, particularly in combination with TKIs, is an innovative approach to enhancing treatment outcomes in CML patients, irrespective of BCR::ABL1 mutation status. This study not only identified a new pathway contributing to TKI resistance but also revealed the possibility of targeting tumoral VISTA as a means of overcoming this significant clinical challenge.

Advancement of DDR1 and DDR2 Inhibitors: Therapeutic Potential of Bioactive Compounds, Designing Strategies, and Structure‐Activity Relationship (SAR)

AbstractDDR1 and DDR2 are nonintegrin collagen receptors in the receptor tyrosine kinase family. Both DDRs bind to various collagen types and perform crucial functions in embryo development. DDRs are different from other receptor tyrosine kinases due to their interaction with extracellular matrix components and unusual activation kinetics. DDR regulates cell migration, survival, proliferation, differentiation, and extracellular matrix remodeling. Dysregulated DDR function is linked to the advancement of several human illnesses, including fibrosis, arthritis, neurodegenerative diseases, and cancer. DDRs play a vital role in disease progression and development. Therefore, the use of DDR inhibitors represents a promising therapeutic strategy, particularly for disorders with limited therapy alternatives. In recent years, DDRs have been regarded as attractive targets for drug development, as evidenced by a significant rise in research in this field. The current review illustrates about recent advancement of small molecules, their designing strategies and structure‐activity relationship. The DDR inhibitors can contain various core structures such as pyrimidine, phthalazine, pyrazole, pyrazine, imidazo[1,2‐a]sspyrazine, quinazoline, and thieno[3,2‐b]pyridin‐7‐yl derivatives. Furthermore, based on the constructive analysis of the published derivatives, we found that the majority of the powerful compounds have a similar scaffold (amide linker, hydrophobic tail, hinge binder with or without spacer). Among the different literature, the most potent compounds 4 (imidazo[1,2‐a]pyrazine), 5 (pyridine), 19 (pyridine), and 24 (quinazoline) displayed potent activity against DDR1 with IC50 values ranging from 2.26 – 4.67 nM, while DDR2 IC50 values ranging from 3.2 – 7.29 nM. This approach will help medicinal chemists to refine and develop novel small molecules targeting DDR1 and DDR2.

Effects of tyrosine kinase inhibitors used for the treatment of non-small cell lung carcinoma on cytochrome P450 2J2 activities

1. Cytochrome P450 (CYP) 2J2 is responsible for the epoxidation of arachidonic acid, producing epoxyeicosatrienoic acids (EETs) that are known to enhance tumorigenesis. CYP2J2 is prominently expressed in the heart and also found in the lungs. Furthermore, the expression level of CYP2J2 in tumour tissues is higher than that in adjacent normal tissues. Non-small cell lung carcinoma is a common cancer, and tyrosine kinase inhibitors (TKIs) are powerful tools for its treatment. This study aimed to elucidate the inhibitory effects of 17 TKIs on CYP2J2 activity using LC-MS/MS. 2. Seventeen TKIs exhibited different inhibitory effects on CYP2J2-catalysed astemizole O-demethylation in recombinant CYP2J2. Pralsetinib and selpercatinib showed strong competitive inhibition, with inhibition constant values of 0.48 and 1.1 µM, respectively. They also inhibited other CYP2J2 activities, including arachidonic acid epoxidation, hydroxyebastine carboxylation, and rivaroxaban hydroxylation. 3. In conclusion, we showed that pralsetinib and selpercatinib strongly inhibit CYP2J2 activity. Inhibition of 14,15-EET production by these TKIs may be a novel mechanism for suppressing tumour growth and proliferation. Additionally, when these TKIs are co-administered with a CYP2J2 substrate, we may consider the possibility of drug–drug interactions via CYP2J2 inhibition.