Involvement Of Tyrosine Kinase Research Articles

Novel ETV6::RAPGEF6 fusion gene in chronic eosinophilic leukemia: compiling evidence on the role of IL3 overexpression in tumorigenesis.

Chronic eosinophilic leukemia (CEL) is a rare myeloproliferative neoplasm. Diagnosis of CEL is often challenging, notably because of the lack of recurrent and specific molecular event. We report here a case of CEL occurring in a 49-year-old man who presented a persistent hypereosinophilia (HE) associated with anemia and thrombopenia. Karyotyping showed a translocation t(5;12)(q31;p13). Targeted RNA Sequencing identified a novel ETV6::RAPGEF6 fusion gene, confirmed by RT-PCR. Despite several lines of treatment, the patient died after 16 months of duration with transformation to acute myeloid leukemia (AML).Contrary to myeloid/lymphoid neoplasms with eosinophilia and tyrosine kinase gene fusions (MLN-TK), where fusion genes are both class defining and involve tyrosine kinase genes as the 3' partner, fusion genes are exceedingly rare in non-MLN-TK myeloid malignancies with HE. The most reported fusion gene is ETV6::ACSL6, in rare cases. Previously, overexpression of IL3 (interleukin 3) has been described in myeloid neoplasms with ETV6::ACSL6 (previously named ACS2). In our case of CEL with the ETV6::RAPGEF6 fusion, we also demonstrated overexpression of IL3, which could potentially result from the proximity of the IL3 gene to RAPGEF6, similar to what is observed with ACSL6 and IL3. The use of RNA sequencing in routine diagnosis of CEL could provide evidence for clonal event such as gene fusion, improving diagnosis as well as prognosis and therapeutic approaches.

Capabilities of positron emission tomography/computed tomography in a comparative assessment of the effect of various targeted therapy options in patients with <i>EGFR</i>-mutated non-small-cell lung cancer

BACKGROUND: No publications in the Russian medical literature have examined the potential of positron emission tomography combined with computed tomography through a comparative evaluation of the effect of various targeted therapies involving tyrosine kinase inhibitors in patients with non-small cell lung cancer and mutations in the EGFR gene. AIM: To explore the capabilities of positron emission tomography combined with computed tomography based on the RECIST 1.1 criteria and changes in SUVmax and SUVmean metabolic parameters for the comparative assessment of the tumor response to targeted monotherapy and combination therapy with tyrosine kinase inhibitors in patients with EGFR-mutant non-small cell lung cancer. MATERIALS AND METHODS: The 2019–2022 examination records of positron emission tomography combined with computed tomography with 18F-fluorodeoxyglucose (18F-FDG) in 105 patients with non-small cell lung cancer were analyzed, including 75 patients with EGFR-activating mutation. The radiation exposure was adjusted individually and ranged from 45 to 90 mSv. The volume activity of the 18F-FDG radiopharmaceutical was 260–500 MBq. The change in the total largest diameters of the target lesions and SUVmax and SUVmean metabolic parameters were assessed before treatment initiation and 1.5–2.0 months after it. The follow-up duration for the changes in positron emission tomography combined with computed tomography findings in 17 patients with non-small cell lung cancer was at least 12 months. RESULTS: According to positron emission tomography combined with computed tomography images and SUVmax and SUVmean changes, disease progression was significantly less common (p = 0.043 and p =0.029) in patients with EGFR-mutant non-small cell lung cancer from Groups 2 and 3 who received combination therapy with tyrosine kinase inhibitors and bevacizumab or chemotherapy than in Group 1 and control group (4.2% vs. 20.0%–21.8%). An insignificant trend (p =0.092) to a higher partial response to therapy (58.3% vs. 40.0%) was noted. Similar changes in the total largest diameters of the target lesions at the early stage of therapy appeared to be not significant (p =0.187). Within the long-term follow-up of some patients with non-small cell lung cancer, in at least 50% of cases, changes in the total largest lesion diameters are consistent with the relevant SUVmax and SUVmean alterations found in the first control study. CONCLUSIONS: Based on the positron emission tomography combined with computed tomography data and alterations in SUVmax and SUVmean metabolic parameters, the early tumor response to combined therapy with tyrosine kinase inhibitors and bevacizumab or chemotherapy compared with targeted monotherapy with tyrosine kinase inhibitors or chemotherapy of the control group was characterized by a significantly lower rate of metabolic disease progression, although a similar tendency of the change in the total largest diameters of target lesions according to RECIST 1.1. was not significant. Changes in SUVmax and SUVmean metabolic parameters at the early stage of therapy are at least 50% faster than similar changes in the total largest diameters of the target lesions, which can be used for the timely identification of patients with a high risk of further progression as determined by RECIST 1.1.

Asciminib: the next-generation bullet for first-line treatment of chronic myeloid leukemia

The standard of care for chronic myeloid leukemia (CML) involves tyrosine kinase inhibitors (TKIs), which suppress tyrosine kinase activity of BCR::ABL1. Hochhaus etal. reported that asciminib, a BCR::ABL1 inhibitor specifically targeting the ABL myristoyl pocket, showed superior efficacy and favorable safety compared with TKIs in the phase 3 ASC4FIRST trial in patients with newly diagnosed chronic-phase CML.1.

First-Line Treatments and Management of Metastatic Renal Cell Carcinoma Patients: An Italian Interdisciplinary Uro-Oncologic Group Algorithm.

The treatment landscape for metastatic renal cell carcinoma (mRCC) has undergone significant transformations in recent years. The introduction of novel combination therapies involving tyrosine kinase inhibitors (TKI) and immune checkpoint inhibitors has resulted in improved oncological outcomes compared to traditional TKI monotherapy. In this evolving paradigm, the pivotal role of the multidisciplinary tumor board is underscored, particularly in shaping the therapeutic trajectory for patients eligible for locoregional interventions like cytoreductive nephrectomy and metastasectomy. In cases where systemic treatment is deemed appropriate, the absence of direct comparisons among the various combination therapies complicates the selection of a first-line approach. The clinician is faced with the challenge of making decisions based on patient-specific factors such as performance status, risk classification according to the International Metastatic Renal Cell Carcinoma Database Consortium, comorbidities, and disease characteristics, including the number and location of metastases and tumor histology. Considering these concerns, we propose, as a member of a Tuscany Interdisciplinary Uro-Oncologic Group, an algorithm to streamline the decision-making process for mRCC patients, offering guidance to clinicians in their day-to-day clinical practice.

Abstract 5670: CRISPR-Mediated knockout of Ceruloplasmin (CP) and UCHL1 reveals angiogenic role in renal cell carcinoma (RCC) cell survival and proliferation

Abstract Clear cell renal cell carcinoma (ccRCC) is the most prevalent subtype of renal cell carcinoma, accounting for approximately 70% of all cases. Therapeutic treatment for metastatic ccRCC involve tyrosine kinase inhibitors or mTOR inhibiters. While these drugs extend patient survival, it also introduces a range of adverse side effects. Utilizing snRNA sequencing, snATACseq, and spatial transcriptomics, two potential ccRCC tumor specific markers have been identified: ceruloplasmin (CP) and UCHL1. These markers are notably overexpressed in a majority of ccRCC tumor cells and elevated CP levels have been correlated with reduced patient survival. To investigate the roles of CP and UCHL1 in ccRCC, CRISPR-based knockout experiments were conducted on two RCC cell lines, namely RCC4-VHL- and Caki-1. Through cell line characterization assays, we find that the absence of CP and UCHL1 impairs the cells' capabilities to migrate, proliferate, and adhere. Additionally, Cell-Derived Xenografts (CDX) of the knockout cell lines in nude mice revealed that cells lacking UCHL1 exhibited slower tumor growth compared to their parental lines. Bulk RNA sequencing further suggested a potential interrelationship between CP and UCHL1, as CP knockout cells showed increased UCHL1 expression relative to the parental line. These findings open new avenues for potential therapeutic strategies and biomarkers in the treatment and screening of ccRCC and further elevates our understandings of the roles of CP and UCHL1 in RCC tumor progression. Citation Format: Wagma Caravan, Yige Wu, Preet Lal, Kazu Sato, Yize Li, Nataly Naser Al Deen, Siqi Chen, Ateih Abedin, Feng Chen, Li Ding. CRISPR-Mediated knockout of Ceruloplasmin (CP) and UCHL1 reveals angiogenic role in renal cell carcinoma (RCC) cell survival and proliferation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5670.

Chronic Myeloid Leukemia/Myelofibrosis: TKI Therapy and Toxicity Management

Recent advances in the understanding of the molecular basis of chronic myeloid leukemia (CML) and myelofibrosis have led to more effective treatment options, with survival now close to that of age-matched controls in CML. The latest updates to the NCCN Guidelines for CML reflect the rapidly evolving treatment landscape, emphasizing the increasing importance of personalized medicine and various targeted therapies. For patients with CML, standard of care involves tyrosine kinase inhibitors such as imatinib, dasatinib, bosutinib, nilotinib, ponatinib, and asciminib, tailored to patient-specific factors and the severity of adverse events. In patients with myelofibrosis, the Janus kinase inhibitors ruxolitinib, pacritinib, and fedratinib have yielded improved outcomes. Critical strategies for managing treatment-related adverse events to optimize the quality of life for patients with these hematologic malignancies were also highlighted.

Advances in molecular evaluation of myeloproliferative neoplasms.

Myeloproliferative neoplasms (MPN) are a group of clonal hematopoietic stem cell disorders with uncontrolled proliferation of one or more hematopoietic cell types, including myeloid, erythroid and megakaryocytic lineages, and minimal defect in maturation. Most MPN are associated with well-defined molecular abnormalities involving genes that encode protein tyrosine kinases that lead to constitutive activation of the downstream signal transduction pathways and confer cells proliferative and survival advantage. Genome-wide sequencing analyses have discovered secondary cooperating mutations that are shared by most of the MPN subtypes as well as other myeloid neoplasms and play a major role in disease progression. Without appropriate management, the natural history of most MPN consists of an initial chronic phase and a terminal blast phase. Molecular aberrations involving protein tyrosine kinases have been used for the diagnosis, classification, detection of minimal/measurable residual disease, and target therapy. We review recent advances in molecular genetic aberrations in MPN with a focus on MPN associated with gene rearrangements or mutations involving tyrosine kinase pathways.

A review on emerging targeted therapies for the management of metastatic colorectal cancers

Colorectal cancers are among the most commonly found cancers over the world. In spite of the recent advancements in diagnosis and prognosis, the management of this metastatic condition remains a challenge. The utility of monoclonal antibodies in the healing of patients with colorectal cancer has opened a new chapter in the quest for newer therapies. The resistance to the standard treatment regimen made it mandatory to search for newer targets. Mutagenic alterations in the gene engaged in cellular differentiation and growth pathway have been the reason for resistance to treatment. The newer therapies target the various proteins and receptors involved in the signal transduction and down streaming pathways leading to cell proliferation. This review presents an insight into the newer targeted therapies for colorectal cancer involving tyrosine kinase blockers, epidermal growth factor receptors, vascular endothelial growth factor, immune checkpoint therapy, and BRAF inhibitors.

Spectrum of kinase gene rearrangements in a large series of paediatric inflammatory myofibroblastic tumours.

Inflammatory myofibroblastic tumours (IMTs), being an exceptionally rare category of paediatric neoplasms, often contain druggable gene rearrangements involving tyrosine kinases. This study presents a large consecutive series of IMTs which were analysed for the presence of translocations by the PCR test for 5'/3'-end ALK, ROS1, RET, NTRK1, NTRK2 and NTRK3 unbalanced expression, variant-specific PCR for 47 common gene fusions and NGS TruSight RNA fusion panel. Kinase gene rearrangements were detected in 71 of 82 (87%) IMTs (ALK: n = 47; ROS1: n = 20; NTRK3: n = 3; PDGFRb: n = 1). The test for unbalanced expression had 100% reliability in identifying tumours with ALK fusions, but failed to reveal ROS1 rearrangements in eight of 20 (40%) ROS1-driven IMTs; however, ROS1 alterations were detectable by variant-specific PCR in 19 of 20 (95%) cases. ALK rearrangements were particularly common in patients below 1 year of age (10 of 11 (91%) versus 37 of 71 (52%), P = 0.039). ROS1 fusions occurred more often in lung IMTs than in tumours of other organs (14 of 35 (40%) versus six of 47 (13%), P = 0.007). Among 11 IMTs with no kinase gene rearrangement identified, one tumour demonstrated ALK activationvia gene amplification and overexpression, and another neoplasm carried COL1A1::USP6 translocation. PCR-based pipeline provides a highly efficient and non-expensive alternative for molecular testing of IMTs. IMTs with no detectable rearrangements need further studies.

Whole-exome sequencing and bioinformatic analyses revealed differences in gene mutation profiles in papillary thyroid cancer patients with and without benign thyroid goitre background.

Papillary thyroid cancer (PTC) is the most common thyroid malignancy. Concurrent presence of cytomorphological benign thyroid goitre (BTG) and PTC lesion is often detected. Aberrant protein profiles were previously reported in patients with and without BTG cytomorphological background. This study aimed to evaluate gene mutation profiles to further understand the molecular mechanism underlying BTG, PTC without BTG background and PTC with BTG background. Patients were grouped according to the histopathological examination results: (i) BTG patients (n = 9), (ii) PTC patients without BTG background (PTCa, n = 8), and (iii) PTC patients with BTG background (PTCb, n = 5). Whole-exome sequencing (WES) was performed on genomic DNA extracted from thyroid tissue specimens. Nonsynonymous and splice-site variants with MAF of ≤ 1% in the 1000 Genomes Project were subjected to principal component analysis (PCA). PTC-specific SNVs were filtered against OncoKB and COSMIC while novel SNVs were screened through dbSNP and COSMIC databases. Functional impacts of the SNVs were predicted using PolyPhen-2 and SIFT. Protein-protein interaction (PPI) enrichment of the tumour-related genes was analysed using Metascape and MCODE algorithm. PCA plots showed distinctive SNV profiles among the three groups. OncoKB and COSMIC database screening identified 36 tumour-related genes including BRCA2 and FANCD2 in all groups. BRAF and 19 additional genes were found only in PTCa and PTCb. "Pathways in cancer", "DNA repair" and "Fanconi anaemia pathway" were among the top networks shared by all groups. However, signalling pathways related to tyrosine kinases were the most significantly enriched in PTCa while "Jak-STAT signalling pathway" and "Notch signalling pathway" were the only significantly enriched in PTCb. Ten SNVs were PTC-specific of which two were novel; DCTN1 c.2786C>G (p.Ala929Gly) and TRRAP c.8735G>C (p.Ser2912Thr). Four out of the ten SNVs were unique to PTCa. Distinctive gene mutation patterns detected in this study corroborated the previous protein profile findings. We hypothesised that the PTCa and PTCb subtypes differed in the underlying molecular mechanisms involving tyrosine kinase, Jak-STAT and Notch signalling pathways. The potential applications of the SNVs in differentiating the benign from the PTC subtypes requires further validation in a larger sample size.

A New Paradigm of Cardio-Hematological Monitoring in Chronic Myeloid Leukemia Patients Treated With Tyrosine Kinase Inhibitors.

Significant progress has been achieved in treating patients with onco-hematological diseases, including chronic myeloid leukemia (CML). This is primarily associated with the development of targeted therapy involving tyrosine kinase inhibitors (TKIs), such as imatinib, nilotinib, bosutinib, dasatinib, and ponatinib. Along with the increased survival of patients with CML, special attention has recently been paid to cardiovascular complications in CML patients due to the prevalence of cardiovascular diseases in the general population and the toxicity profile of targeted drugs.This article presents the strategy for reducing cardiovascular risk in CML patients treated with TKIs. We discuss the components of cardiovascular risk in CML patients and the findings of current studies. Current data confirm the increased cardiovascular risk in the CML population compared to the general population, which necessitates the widespread introduction of cardiovascular prevention strategies in CML patients. The pharmacokinetics and pharmacodynamics of TKIs on the cardiovascular system are discussed. We propose two main approaches in the strategy of cardiovascular risk prevention in patients with CML, namely, before the start of TKI administration and during TKI treatment. This article presents the diagnostic assessment before prescribing TKIs, as well as while monitoring TKI therapy, and discusses the features of the choice of TKIs depending on patients’ general and cardiovascular comorbidity. Emphasis is placed on the risk stratification in patients with CML following general population algorithms, lifestyle modifications, and statin therapy for achieving the target levels of cardiovascular indicators. We also discuss unsolved questions in the current clinical guidelines and ways to further develop a cardiovascular risk-reducing strategy for CML patients.

Therapeutic Options in Neuro-Oncology.

One of the biggest challenges in neuro-oncology is understanding the complexity of central nervous system tumors, such as gliomas, in order to develop suitable therapeutics. Conventional therapies in malignant gliomas reconcile surgery and radiotherapy with the use of chemotherapeutic options such as temozolomide, chloroethyl nitrosoureas and the combination therapy of procarbazine, lomustine and vincristine. With the unraveling of deregulated cancer cell signaling pathways, targeted therapies have been developed. The most affected signaling pathways in glioma cells involve tyrosine kinase receptors and their downstream pathways, such as the phosphatidylinositol 3-kinases (PI3K/AKT/mTOR) and mitogen-activated protein kinase pathways (MAPK). MAPK pathway inhibitors include farnesyl transferase inhibitors, Ras kinase inhibitors and mitogen-activated protein extracellular regulated kinase (MEK) inhibitors, while PI3K/AKT/mTOR pathway inhibitors are divided into pan-inhibitors, PI3K/mTOR dual inhibitors and AKT inhibitors. The relevance of the immune system in carcinogenesis has led to the development of immunotherapy, through vaccination, blocking of immune checkpoints, oncolytic viruses, and adoptive immunotherapy using chimeric antigen receptor T cells. In this article we provide a comprehensive review of the signaling pathways underlying malignant transformation, the therapies currently used in the treatment of malignant gliomas and further explore therapies under development, including several ongoing clinical trials.

Cabozantinib in the treatment of metastatic renal cell carcinoma - final data analysis from four oncology centers in the Czech Republic.

Current standard treatments for patients with metastatic renal cell carcinoma (mRCC) involve tyrosine kinase inhibitors (TKI) that inhibit angiogenesis. Cabozantinib is a multi TKI used for the treatment of mRCC in the first- and second-line setting. The aim of this study was the final analysis of treatment outcomes in patients with metastatic renal cell carcinoma (mRCC) treated with cabozantinib after previous targeted therapy. A total of 54 patients with mRCC from four oncology centers in the Czech Republic were evaluated retrospectively; the median follow-up was 18.5 months. Cabozantinib was administered in a dose of 60mg/day, a subset of patients received an initial dose of 40mg/day. The treatment was administered until the progression. The Kaplan-Meier analysis was used to calculate progression free survival (PFS) and overall survival (OS). We performed a multivariate analysis of risk factors for treatment outcomes (PFS, OS) by regression analysis. All statistics were evaluated at the significance level α = 0.05. The median PFS in all patients was 9.3 months (95% CI 7.2 - 11.4). The median OS in all patients was 21.9 months (95% CI 15.5 - 28.4). The median PFS in patients with bone metastases was not statistically significantly different compared with patients without bone metastases (9.3 vs 8.7 months, P = 0.53). The median OS in patients with bone metastases was statistically significantly shorter compared with patients without bone metastases (17.7 vs 26.8 months, P = 0.021). A treatment response was observed in 40.7 % of cases, including one complete remission. The regression analysis demonstrated a significant effect on OS in patients with the presence of subsequent treatment (P = 0.001), patients with treatment duration of first line therapy 6 months (P = 0.019) and 12 months (P = 0.003) and in patients without bone metastases (P = 0.021). Our final analysis of patients with mRCC treated with cabozantinib after previous targeted therapy confirmed its effectiveness.

Pulmonary metastasectomy in renal cell carcinoma: a mainstay of multidisciplinary treatment

Renal cell carcinoma (RCC) remains a public health issue and seems to be increasing. A significant proportion of RCC patients will develop pulmonary metastasis at some point in their evolution. In this review, we aimed to update the surgical management of pulmonary metastases as well as systemic therapy, including targeted therapies, according to recent data in the literature. We retrospectively reviewed studies evaluating the benefit of pulmonary metastasectomy in RCC patients and evaluating the place of different chemotherapies, targeted therapies and immunotherapies through November 1, 2019. Several retrospective studies have shown the benefit of pulmonary metastasectomy in metastatic RCC (mRCC), most in a situation with only pulmonary metastases. According to the prognostic criteria of the IMDC risk model, the patient is classified into a prognostic group to identify the best systemic treatment. With the development of targeted therapies, the modalities are multiple and may involve tyrosine kinase inhibitors/checkpoint inhibitors and soon vaccine therapy or CAR-T cells. At the local level, in patients who cannot benefit from surgery, stereotactic radiotherapy or radiofrequency has a place to be considered. Although there is a lack of a randomized study, pulmonary metastasectomy appears to be feasible and effective. The place and modalities of systemic therapies in the era of targeted therapies remain to be more clearly defined.

Regulation of OATP1B1 Function by Tyrosine Kinase-mediated Phosphorylation.

OATP1B1 (SLCO1B1) is the most abundant and pharmacologically relevant uptake transporter in the liver and a key mediator of xenobiotic clearance. However, the regulatory mechanisms that determine OATP1B1 activity remain uncertain, and as a result, unexpected drug-drug interactions involving OATP1B1 substrates continue to be reported, including several involving tyrosine kinase inhibitors (TKI). OATP1B1-mediated activity in overexpressing HEK293 cells and hepatocytes was assessed in the presence of FDA-approved TKIs, while rosuvastatin pharmacokinetics in the presence of an OATP1B1 inhibiting TKI were measured in vivo. Tyrosine phosphorylation of OATP1B1 was determined by LC/MS-MS-based proteomics and transport function was measured following exposure to siRNAs targeting 779 different kinases. Twenty-nine of 46 FDA-approved TKIs studied significantly inhibit OATP1B1 function. Inhibition of OATP1B1 by TKIs, such as nilotinib, is predominantly noncompetitive, can increase systemic concentrations of rosuvastatin in vivo, and is associated with reduced phosphorylation of OATP1B1 at tyrosine residue 645. Using genetic screens and functional validation studies, the Src kinase LYN was identified as a potential regulator of OATP1B1 activity that is highly sensitive to inhibition by various TKIs at clinically relevant concentrations. A novel kinase-dependent posttranslational mechanism of OATP1B1 activation was identified and interference with this process by TKIs can influence the elimination of a broad range of xenobiotic substrates.

The potential of A. Muricata Bioactive Compounds to Inhibit HIF1α Expression Via Disruption of Tyrosine Kinase Receptor Activity: an In Silico Study.

Background:Cancer is a debilitating disease that is on the increase in both developed and developing countries. The plant extract of A. muricata have been known to have a variety of anticancer effects, including anti-angiogenic potential. An in silico study is needed as a preliminary study to understand the mechanism underline this process.Objective:The aim of this study was to investigate the potential of the bioactive compounds of A. muricata in regulating angiogenesis process, primarily by the regulation of hypoxia inducible factor (HIF)-1α expression by in silico study.Methods:This study was performed by in silico analysis including the bioactive compounds preparation, biological activity prediction, protein target and pathway analysis, 3D protein modelling, protein-ligand and protein-protein docking, and the visualization of docking results.Results:There are 3 bioactive compounds of A. muricata with the ability to inhibit HIF-1α expression, including kaempferol, genistein, and glycitein. The inhibition of HIF-1α expression was associated with phosphoinositide 3-kinases (PI3K)/Akt signaling pathway, which involved tyrosine kinase receptor activity on the cell membrane. Based on the silico analysis in this study, we shown that kaempferol, genistein, and glycitein inhibit HIF-1α expression through the disruption of interleukin (IL)-6R and toll-like receptor (TLR)-4 and their respective ligands interaction.Conclusion:The findings of this study show that A. muricata bioactive compounds could inhibit HIF-1α expression through disruption of the tyrosine kinase receptor binding with its ligand.

Narrative review of molecular pathways of kinase fusions and diagnostic approaches for their detection in non-small cell lung carcinomas.

The discovery of actionable oncogenic driver alterations has significantly improved treatment options for patients with advanced non-small cell lung cancer (NSCLC). In lung adenocarcinoma (LUAD), approved drugs or drugs in clinical development can target more than half of these altered oncogenic driver genes. In particular, several gene fusions have been discovered in LUAD, including ALK, ROS1, NTRK, RET, NRG1 and FGFR. All these fusions involve tyrosine kinases (TK), which are activated due to structural rearrangements on the DNA level. Although the overall prevalence of these fusions in LUAD is rare, their detection is extremely important, as they are linked to an excellent response to TK inhibitors. Therefore, reliable screening methods applicable to small tumor samples (biopsies and cytology specimens) are required in the diagnostic workup of advanced NSCLC. Several methods are at disposal in a routine laboratory to demonstrate, directly or indirectly, the presence of a gene fusion. These methods include immunohistochemistry (IHC), fluorescence in-situ hybridization (FISH), reverse transcriptase-polymerase chain reaction (RT-PCR), multiplex digital color-coded barcode technology or next-generation sequencing (NGS) either on DNA or RNA level. In our review, we will summarize the increasing number of relevant fusion genes in NSCLC, point out their underlining molecular mechanisms and discuss different methods for the detection of fusion genes.

Treatment patterns, outcomes and clinical characteristics in advanced renal cell carcinoma: a real-world US study.

Aim: Assessing treatment patterns, outcomes and clinical characteristics in advanced renal cell carcinoma clinical practice. Materials & methods: A US cross-sectional physician survey conducted February-September 2019. Results: Surveyed physicians reported first-line treatment of 445 patients involving tyrosine kinase inhibitor monotherapy (51.0%), immuno-oncology (IO/IO combination) therapy (25.8%) or other regimens (23.1%). A total of60.9% had physician-assessed IMDC risk. Of these 61.9, 50.9 and 27.6% of patients with favorable, intermediate and poor risk, respectively, received tyrosine kinase inhibitor monotherapy. A total of16.7, 26.9 and 34.5% of patients with favorable, intermediate or poor risk received IO/IO combination therapy. Complete/partial responses (∼35% patients) remained comparable across first-line treatments. Conclusion: Guideline-recommended therapies are not widely prescribed. Many patients experienced poor clinical outcomes highlighting a need for more effective treatments.

Abstract 2991: Establishment of patient-derived cancer cell lines to elucidate the resistant mechanism of tyrosine kinase inhibitors

Abstract In non-small cell lung cancer (NSCLC), several somatic mutations such as EGFR and EML4-ALK have been identified in a significant subgroup of patients. Multiple clinical trials involving tyrosine kinase inhibitors (TKIs) have demonstrated significant improvement in the prognosis of lung cancer patients with these mutations. However, in clinic, lung cancer cells gradually acquire resistance to these inhibitors in a span of approximately 1 - 2 years. In TKI resistant lung cancer patients, next-generation sequencing of clinical samples from individual patients enables the detection of genetic alterations that contribute to drug resistance, such as EGFR T790M and EGFR C797S mutations. However, it does not always offer an appropriate treatment strategy for patients with acquired resistance. In contrast, the presence of living cancer cells allows researchers to biologically evaluate the roles of mutations or bypass pathways. For a thorough clarification of resistance mechanisms, living cancer cells, in addition to genomic information, are essential. In our report, we have established six patient-derived cancer cells (PDCs) from NSCLC patients who were treated with various TKIs and thereafter experienced disease progression. The success rate for PDCs was as high as 50% (6/12). Upon the established cell lines, 2 cases had EML4-ALK and the rest had EGFR mutation as an oncogene. After establishing the PDCs, TKI resistance was confirmed by MTS cell proliferation assay and 5 of 6 cases showed matched TKI resistance referring to the clinical background. To elucidate the adaptive resistant mechanisms in PDCs, Sanger sequence was performed and none of the gene mutations that have been previously reported to contribute to resistance to TKIs was detected. Next, to investigate the bypass pathway activation in these cell lines, we performed phospho-receptor tyrosine kinase (RTK) array screening. Interestingly, 4 of 5 cases showed activation of bypass RTK signaling and 3 of 4 cases obtained combined effectiveness with the additional RTK inhibitor. Furthermore, we have performed western blotting in 3 PDCs and detected that combination treatment attenuated the phosphorylation of the downstream molecules. In conclusion, by using PDCs, we have clarified the mechanism of acquired resistance and detected the treatment strategy to overcome these resistances. The findings suggest that PDCs may help develop precision medicine for TKI resistant patients. Citation Format: Tadashi Manabe, Hiroyuki Yasuda, Hideki Terai, Junko Hamamoto, Toshiki Ebisudani, Keigo Kobayashi, Keita Masuzawa, Shinnosuke Ikemura, Ichiro Kawada, Koichi Fukunaga, Kenzo Soejima. Establishment of patient-derived cancer cell lines to elucidate the resistant mechanism of tyrosine kinase inhibitors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2991.

The Current Genomic and Molecular Landscape of Philadelphia-like Acute Lymphoblastic Leukemia.

Philadelphia (Ph)-like acute lymphoblastic leukemia (ALL) is a high-risk B-cell Acute Lymphoblastic Leukemia (B-ALL) characterized by a gene expression profile similar to Ph-positive B-ALL but lacking the BCR-ABL1 translocation. The molecular pathogenesis of Ph-like B-ALL is heterogenous and involves aberrant genomics, receptor overexpression, kinase fusions, and mutations leading to kinase signaling activation, leukemogenic cellular proliferation, and differentiation blockade. Testing for the Ph-like signature, once only a research technique, is now available to the clinical oncologist. The plethora of data pointing to poor outcomes for this ALL subset has triggered investigations into the role of targeted therapies, predominantly involving tyrosine kinase inhibitors that are showing promising results.