Transgenerational increases in DNA methylation in Arabidopsis plants defective in active DNA demethylation.

Spontaneous gain or loss of DNA methylation occurs in plant and animal genomes, and DNA methylation changes can lead to meiotically stable epialleles that generate heritable phenotypic diversity. However, it is unclear whether transgenerational epigenetic stability may be regulated by any cellular factors. Here, we examined spontaneously occurring variations in DNA methylation in wild-type and ros1 mutant Arabidopsis plants that were propagated for ten generations from single-seed descent. We found that the ros1 mutant, which is defective in active DNA demethylation, showed an increased transgenerational epimutation rate. The ros1 mutation led to more spontaneously gained methylation than lost methylation at individual cytosines, compared to the wild type which had similar numbers of spontaneously gained and lost methylation cytosines. Consistently, transgenerational differentially methylated regions were also biased toward hypermethylation in the ros1 mutant. Our results reveal a genetic contribution of the ROS1 DNA demethylase to transgenerational epigenetic stability and suggest that ROS1 may have an unexpected surveillance function in preventing transgenerational DNA methylation increases.

CRISPR/Cas9-edited ROS1 + non-small cell lung cancer cell lines highlight differential drug sensitivity in 2D vs 3D cultures while reflecting established resistance profiles.

INTRODUCTION: The study of resistance-causing mutations in oncogene-driven tumors is fundamental to guide clinical decisions. Several point mutations affecting the ROS1 kinase domain have been identified in the clinical setting, but their impact requires further exploration, particularly in improved pre-clinical models. Given the scarcity of solid pre-clinical models to approach rare cancer subtypes like ROS1 + NSCLC, CRISPR/Cas9 technology allows the introduction of mutations in patient-derived cell lines for which resistant variants are difficult to obtain due to the low prevalence of cases within the clinical setting. METHODS: In the SLC34A2-ROS1 rearranged NSCLC cell line HCC78, we knocked-in through CRISPR/Cas9 technology three ROS1 drug resistance-causing mutations: G2032R, L2026M and S1986Y. Such variants are located in different functional regions of the ROS1 kinase domain, thus conferring TKI resistance through distinct mechanisms. We then performed pharmacological assays in 2D and 3D to assess the cellular response of the mutant lines to crizotinib, entrectinib, lorlatinib, repotrectinib and ceritinib. In addition, immunoblotting assays were performed in 2D-treated cell lines to determine ROS1 phosphorylation and MAP kinase pathway activity. The area over the curve (AOC) defined by the normalized growth rate (NGR_fit) dose-response curves was the variable used to quantify the cellular response towards TKIs. RESULTS: Spheroids derived from ROS1G2032R cells were significantly more resistant to repotrectinib (AOC fold change = - 7.33), lorlatinib (AOC fold change = - 6.17), ceritinib (AOC fold change = - 2.8) and entrectinib (AOC fold change = - 2.02) than wild type cells. The same cells cultured as a monolayer reflected the inefficacy of crizotinib (AOC fold change = - 2.35), entrectinib (AOC fold change = - 2.44) and ceritinib (AOC fold change = - 2.12) in targeting the ROS1 G2032R mutation. ROS1L2026M cells showed also remarkable resistance both in monolayer and spheroid culture compared to wild type cells, particularly against repotrectinib (spheroid AOC fold change = - 2.19) and entrectinib (spheroid AOC fold change = - 1.98). ROS1S1986Y cells were resistant only towards crizotinib in 2D (AOC fold change = - 1.86). Overall, spheroids showed an increased TKI sensitivity compared to 2D cultures, where the impact of each mutation that confers TKI resistance could be clearly distinguished. Western blotting assays qualitatively reflected the patterns of response towards TKI observed in 2D culture through the levels of phosphorylated-ROS1. However, we observed a dose-response increase of phosphorylated-Erk1/2, suggesting the involvement of the MAPK pathway in the mediation of apoptosis in HCC78 cells. CONCLUSION: In this study we knock-in for the first time in a ROS1 + patient-derived cell line, three different known resistance-causing mutations using CRISPR/Cas9 in the endogenous translocated ROS1 alleles. Pharmacological assays performed in 2D and 3D cell culture revealed that spheroids are more sensitive to TKIs than cells cultured as a monolayer. This direct comparison between two culture systems could be done thanks to the implementation of normalized growth rates (NGR) to uniformly quantify drug response between 2D and 3D cell culture. Overall, this study presents the added value of using spheroids and positions lorlatinib and repotrectinib as the most effective TKIs against the studied ROS1 resistance point mutations.

DNA methylation remodeled amino acids biosynthesis regulates flower senescence in carnation (Dianthus caryophyllus).

Dynamic DNA methylation regulatory networks are involved in many biological processes. However, how DNA methylation patterns change during flower senescence and their relevance with gene expression and related molecular mechanism remain largely unknown. Here, we used whole genome bisulfite sequencing to reveal a significant increase of DNA methylation in the promoter region of genes during natural and ethylene-induced flower senescence in carnation (Dianthus caryophyllus L.), which was correlated with decreased expression of DNA demethylase gene DcROS1. Silencing of DcROS1 accelerated while overexpression of DcROS1 delayed carnation flower senescence. Moreover, among the hypermethylated differentially expressed genes during flower senescence, we identified two amino acid biosynthesis genes, DcCARA and DcDHAD, with increased DNA methylation and reduced expression in DcROS1 silenced petals, and decreased DNA methylation and increased expression in DcROS1 overexpression petals, accompanied by decreased or increased amino acids content. Silencing of DcCARA and DcDHAD accelerates carnation flower senescence. We further showed that adding corresponding amino acids could largely rescue the senescence phenotype of DcROS1, DcCARA and DcDHAD silenced plants. Our study not only demonstrates an essential role of DcROS1-mediated remodeling of DNA methylation in flower senescence but also unravels a novel epigenetic regulatory mechanism underlying DNA methylation and amino acid biosynthesis during flower senescence.

Clinical significance of TP53 alterations in advanced NSCLC patients treated with EGFR, ALK and ROS1 tyrosine kinase inhibitors: An update.

 The development of targeted therapies for non-small cell lung cancer (NSCLC), such as the epidermal growth factor receptor (EGFR), anaplastic lymphoma receptor tyrosine kinase (ALK), and ROS proto-oncogene 1 (ROS1), has improved patients' prognosis and significantly extended progression-free survival. However, it remains unclear why some patients do not benefit from the treatment as much or have a rapid disease progression. It is considered that, apart from the oncogenic driver gene, molecular alterations in a number of caretaker and gatekeeper genes significantly impact the efficacy of targeted therapies. The tumor protein 53 (TP53) gene is one of the most frequently mutated genes in NSCLC. To date, numerous studies have investigated the influence of various TP53 alterations on patient prognosis and responsiveness to therapies targeting EGFR, ALK, or ROS1. This review focuses on the latest data concerning the role of TP53 alterations as prognostic and/or predictive biomarkers for EGFR, ALK, and ROS1 tyrosine kinase inhibitors (TKIs) in advanced NSCLC patients. Since the presence of TP53 mutations in NSCLC has been linked to its decreased responsiveness to EGFR, ALK, and ROS1 targeted therapy in most of the referenced studies, the review also discusses the impact of TP53 mutations on treatment resistance. It seems plausible that assessing the TP53 mutation status could aid in patient stratification for optimal clinical decision-making. However, drawing meaningful conclusions about the clinical value of the TP53 co-mutations in EGFR-, ALK- or ROS1-positive NSCLC is hampered mainly by an insufficient knowledge regarding the functional consequences of the TP53 alterations. The integration of next-generation sequencing into the routine molecular diagnostics of cancer patients will facilitate the detection and identification of targetable genetic alterations along with co-occurring TP53 variants. This advancement holds the potential to accelerate understanding of the biological and clinical role of p53 in targeted therapies for NSCLC.

Expression of NELL2/NICOL-ROS1 lumicrine signaling-related molecules in the human male reproductive tract.

The maturation of spermatozoa is a regulated process, influenced by genes expressing essential secreted proteins in the proximal epididymis. Recent genetic studies in rodents have identified the non-sex steroidal molecular signals that regulate gene expression in the proximal epididymis. Germ cells in the testis secrete ligand proteins into the seminiferous tubule lumen The ligand proteins travel through the male reproductive tract lumen to the epididymis, where they bind to receptors, triggering the differentiation of the luminal epithelium for sperm maturation. It is, however, not fully unveiled if such a testis-epididymis trans-luminal signaling mechanism exists in other species, especially humans. In the present study, the rodent-type testis-epididymis trans-luminal signaling in the human male reproductive tract was evaluated in a step-by-step manner by analyzing testis and epididymis gene expression and signaling mediator protein function. There was a significant correlation between the epididymal expressions of mouse genes upregulated by the trans-luminal signaling and those of their human orthologs, as evaluated by the correlation coefficient of 0.604. The transcript expression of NELL2 and NICOL encoding putative ligand proteins was also observed in human testicular cells. In vitro experiments demonstrated that purified recombinant human NELL2 and NICOL formed a molecular complex with similar properties to rodent proteins, which was evaluated by a dissociation equilibrium constant of 110 nM. Recombinant human NELL2 also specifically bound to its putative receptor human ROS1 in vitro. Collectively, these findings suggest that the rodent-type testis-epididymis secreted signaling mechanism is also possible in the human male reproductive tract.

Discovery of a first-in-class protein degrader for the c-ros oncogene 1 (ROS1).

The c-ros oncogene 1 (ROS1), an oncogenic driver, is known to induce non-small cell lung cancer (NSCLC) when overactivated, particularly through the formation of fusion proteins. Traditional targeted therapies focus on inhibiting ROS1 activity with ROS 1 inhibitors to manage cancer progression. However, a new strategy involving the design of protein degraders offers a more potent approach by completely degrading ROS1 fusion oncoproteins, thereby effectively blocking their kinase activity and enhancing anti-tumour potential. Utilizing PROteolysis-TArgeting Chimera (PROTAC) technology and informed by molecular docking and rational design, we report the first ROS1-specific PROTAC, SIAIS039. This degrader effectively targets multiple ROS1 fusion oncoproteins (CD74-ROS1, SDC4-ROS1 and SLC34A2-ROS1) in engineered Ba/F3 cells and HCC78 cells, demonstrating anti-tumour effects against ROS1 fusion-driven cancer cells. It suppresses cell proliferation, induces cell cycle arrest, and apoptosis, and inhibits clonogenicity. The anti-tumour efficacy of SIAIS039 surpasses two approved drugs, crizotinib and entrectinib, and matches that of the top inhibitors, including lorlatinib and taletrectinib. Mechanistic studies confirm that the degradation induced by 039 requires the participation of ROS1 ligands and E3 ubiquitin ligases, and involves the proteasome and ubiquitination. In addition, 039 exhibited excellent oral bioavailability in a mouse xenograft model, highlighting its potential for clinical application. In conclusion, our study presents a promising and novel therapeutic strategy for ROS1 fusion-positive NSCLC by targeting ROS1 fusion oncoproteins for degradation, laying the foundation for the development of further PROTAC and offering hope for patients with ROS1 fusion-positive NSCLC.

Clinical, Morphological and Molecular Features of Spitz tumors.

Spitz tumors represent a heterogeneous group of challenging melanocytic neoplasms, displaying a range of biological behaviors, spanning from benign lesions, Spitz nevi (SN) to Spitz melanomas (SM), with intermediate lesions in between known as atypical Spitz tumors (AST). They are histologically characterized by large epithelioid and/or spindled melanocytes arranged in fascicles or nests, often associated with characteristic epidermal hyperplasia and fibrovascular stromal changes. In the last decade, the detection of mutually exclusive structural rearrangements involving receptor tyrosine kinases ROS1, ALK, NTRK1, NTRK2, NTRK3, RET, MET, serine threonine kinases BRAF and MAP3K8, or HRAS mutation, led to a clinical, morphological and molecular based classification of Spitz tumors. The recognition of some reproducible histological features can help dermatopathologist in assessing these lesions and can provide clues to predict the underlying molecular driver. In this review, we will focus on clinical and morphological findings in molecular Spitz tumor subgroups.

Yes-associated protein 1 mediates initial cell survival during lorlatinib treatment through AKT signaling in ROS1-rearranged lung cancer.

Tyrosine kinase inhibitors (TKIs) that target the ROS proto-oncogene 1, receptor tyrosine kinase (ROS1) gene have shown dramatic therapeutic effects in patients with ROS1-rearranged non-small-cell lung cancer (NSCLC). Nevertheless, advanced ROS1-rearranged NSCLC is rarely cured as a portion of the tumor cells can survive the initial stages of ROS1-TKI treatment, even after maximum tumor shrinkage. Therefore, understanding the mechanisms underlying initial cell survival during ROS1-TKI treatment is necessary to prevent cell survival and achieve a cure for ROS1-rearranged NSCLC. In this study, we clarified the initial survival mechanisms during treatment with lorlatinib, a ROS1 TKI. First, we established a patient-derived ezrin gene-ROS1-rearranged NSCLC cell line (KTOR71). Then, following proteomic analysis, we focused on yes-associated protein 1 (YAP1), which is a major mediator of the Hippo pathway, as a candidate factor involved in cell survival during early lorlatinib treatment. Yes-associated protein 1 was activated by short-term lorlatinib treatment both in vitro and in vivo. Genetic inhibition of YAP1 using siRNA, or pharmacological inhibition of YAP1 function by the YAP1-inhibitor verteporfin, enhanced the sensitivity of KTOR71 cells to lorlatinib. In addition, the prosurvival effect of YAP1 was exerted through the reactivation of AKT. Finally, combined therapy with verteporfin and lorlatinib was found to achieve significantly sustained tumor remission compared with lorlatinib monotherapy in vivo. These results suggest that YAP1 could mediate initial cell resistance to lorlatinib in KTOR71 cells. Thus, combined therapy targeting both YAP1 and ROS1 could potentially improve the outcome of ROS1-rearranged NSCLC.

ROS1 Alterations as a Potential Driver of Gliomas in Infant, Pediatric, and Adult Patients.

Gliomas harboring oncogenic ROS1 alterations are uncommon and primarily described in infants. Our goal was to characterize the clinicopathological features and molecular signatures of the full spectrum of ROS1 fusion-positive gliomas across all age groups. Through a retrospective multi-institutional collaboration, we report a collection of unpublished ROS1 fusion gliomas along with the characterization and meta-analysis of new and published cases. A cohort of 32 new and 58 published cases was divided into the following 3 age groups: 19 infants, 40 pediatric patients, and 31 adults with gliomas. Tumors in infants and adults showed uniformly high-grade morphology; however, tumors in pediatric patients exhibited diverse histologic features. The GOPC::ROS1 fusion was prevalent (61/79, 77%) across all age groups, and 10 other partner genes were identified. Adult tumors showed recurrent genomic alterations characteristic of IDH wild-type glioblastoma, including the +7/-10/CDKN2A deletion; amplification of CDK4, MDM2, and PDGFRA genes; and mutations involving TERTp, TP53, PIK3R1, PIK3CA, PTEN, and NF1 genes. Infant tumors showed few genomic alterations, whereas pediatric tumors showed moderate genomic complexity. The outcomes were significantly poorer in adult patients. Although not statistically significant, tumors in infant and pediatric patients with high-grade histology and in hemispheric locations appeared more aggressive than tumors with lower grade histology or those in nonhemispheric locations. In conclusion, this study is the largest to date to characterize the clinicopathological and molecular signatures of ROS1 fusion-positive gliomas from infant, pediatric, and adult patients. We conclude that ROS1 likely acts as a driver in infant and pediatric gliomas and as a driver or codriver in adult gliomas. Integrated comprehensive clinical testing might be helpful in identifying such patients for possible targeted therapy.

Pan-tumor survey of ROS1 fusions detected by next-generation RNA and whole transcriptome sequencing.

BACKGROUND: Two ROS1 tyrosine kinase inhibitors have been approved for ROS1 fusion positive (ROS1+) non-small cell lung cancer (NSCLC) tumors. We performed a pan-tumor analysis of the incidence of ROS1 fusions to assess if more ROS1+ patients who could benefit from ROS1 TKIs could be identified. METHODS: A retrospective analysis of ROS1 positive solid malignancies identified by targeted RNA sequencing and whole transcriptome sequencing of clinical tumor samples performed at Caris Life Science (Phoenix, AZ). RESULTS: A total of 259 ROS1+ solid malignancies were identified from approximately 175,350 tumors that underwent next-generation sequencing (12% from targeted RNA sequencing [Archer]; 88% from whole transcriptome sequencing). ROS1+ NSCLC constituted 78.8% of the ROS1+ solid malignancies, follow by glioblastoma (GBM) (6.9%), and breast cancer (2.7%). The frequency of ROS1 fusion was approximately 0.47% among NSCLC, 0.29% for GBM, 0.04% of breast cancer. The mean tumor mutation burden for all ROS1+ tumors was 4.8 mutations/megabase. The distribution of PD-L1 (22C3) expression among all ROS1+ malignancies were 0% (18.6%), 1%-49% (29.4%), and ≥ 50% (60.3%) [for NSCLC: 0% (17.8%); 1-49% (27.7%); ≥ 50% (53.9%). The most common genetic co-alterations of ROS1+ NSCLC were TP53 (29.1%), SETD2 (7.3%), ARIAD1A (6.3%), and U2AF1 (5.6%). CONCLUSIONS: ROS1+ NSCLC tumors constituted the majority of ROS1+ solid malignancies with four major fusion partners. Given that > 20% of ROS1+ solid tumors may benefit from ROS1 TKIs treatment, comprehensive genomic profiling should be performed on all solid tumors.

ROS1 as a possible prognostic biomarker of cervical adenocarcinoma: An exploratory analysis with next-generation sequencing.

OBJECTIVES: Given the differences in clinical and biological characteristics between cervical adenocarcinoma and squamous cell carcinoma, this study aimed to conduct an exploratory analysis to examine the molecular characteristics of cervical adenocarcinoma in a Japanese population. METHODS: This study explored the simultaneous testing of multiple mutations targeting cervical adenocarcinoma using next-generation sequencing (NGS). The following genes were analyzed: BCAR4, CD274, PDCD1LG2, KRAS, ARID1A, PTEN, ALK, EGFR, ROS1, BRAF, PIK3CA, EP300, EBXW7, SHCBP1, TGFBR2, SMAD4, ERBB2, ERBB3, and KLF5. Tumor tissue and blood samples were obtained at the time of primary treatment. The NGS-based molecular profiles obtained from Tokai University (49 specimens) were compared with the registered data in The Cancer Genome Atlas (TCGA) database (133 specimens). RESULTS: The study cohort had higher rates of adenocarcinoma than the TCGA cohort (44.9% vs. 18.0%; P = 0.001). The adenocarcinomas in the study cohort had more alterations in ROS1, EGFR, EP300, SHCBP1, ALK, and PIK3CA than those in the TCGA cohort. Among them, ROS1 had the highest number of gene alterations (median, 7.00 ± 2.63). In the study cohort, patients with a high number of ROS1 alterations had a significantly higher recurrence rate (5-year recurrence rate, 48.8% vs. 14.6%; hazard ratio [HR], 4.32; 95% confidence interval [CI], 1.20-15.50; P = 0.014) and lower overall survival than those with low alterations (5-year survival rate, 70.7% vs. 93.1%; HR, 7.15; 95% CI, 1.08-58.22; P = 0.032). CONCLUSION: The current exploratory analysis suggests that ROS1 gene alteration may be a prognostic biomarker in cervical adenocarcinoma in Japanese patients.

Effectiveness of crizotinib in patients with ROS1-positive non-small-cell lung cancer: real-world evidence in Japan.

Aim: Crizotinib, approved in Japan (2017) for ROS1-positive NSCLC, has limited real-world data. Materials & methods: Crizotinib monotherapy real-world effectiveness and treatment status were analyzed from claims data (June 2017-March 2021; Japanese Medical Data Vision; 58 patients tested for ROS1-NSCLC). Results: Median duration of treatment ([DoT]; primary end point), any line: 12.9 months; 22 patients on crizotinib, 23 discontinued, 13 receiving post-crizotinib treatment. 1L (n = 27) median DoT: 13.0 months (95% CI, 4.4-32.0 months); 13 patients on crizotinib; seven discontinued; seven receiving post-crizotinib treatment. 2L (n = 13) median DoT: 14.0 months (95% CI, 4.6-22.2 months); 2L+ (n = 31): nine patients on crizotinib; 16 discontinued; six receiving post-crizotinib treatment. Post-crizotinib treatments (chemotherapy, cancer immunotherapy, anti-VEGF/R) did not affect crizotinib DoT. Conclusion: Data supplement crizotinib's effectiveness in ROS1-positive NSCLC previously seen in clinical trials/real-world.

Non-small-cell lung cancer (NSCLC) is a common type of cancer in the lung that is often caused by mutations in specific genes in the DNA. One type of NSCLC occurs when you have mutations in a gene called ROS1, whose normal function is not well understood. Crizotinib, an oral medicine, was approved in Japan for the treatment of NSCLC with mutations in ROS1 in 2017; however, this was based upon data from controlled clinical trials. This study was looking at crizotinib use in Japan based upon claims data from the Japanese Medical Data Vision database, which captures all use of medications provided in Japan. Data was collected from June 2017 to March 2021 for 58 Japanese patients who had NSCLC, tested positive for ROS1 mutations, and received crizotinib. Patients took crizotinib for a median of 13.0 months as a first treatment option and 14.0 months as a second treatment option for their NSCLC. The type of and duration of anticancer treatments given before crizotinib did not have an effect on the length of time crizotinib was used. Other treatments outside of crizotinib were given before or after crizotinib and include chemotherapy, therapy that modifies the immune system to treat cancer, or treatments that inhibit the growth of blood vessels that help the cancer grow/spread. Together, these real-world data provide evidence supporting the use of crizotinib in the treatment of patients with NSCLC and ROS1 mutations.

TRUST-II: a global phase II study of taletrectinib in ROS1-positive non-small-cell lung cancer and other solid tumors.

Crizotinib and entrectinib have been approved to treat ROS1 fusion-positive (ROS1+) non-small-cell lung cancer. However, unmet needs remain, including treatment of patients with resistance mutations, efficacy in brain metastasis and avoidance of neurological side effects. Taletrectinib was designed to: improve efficacy; overcome resistance to first-generation ROS1 inhibitors; and address brain metastasis while conferring fewer neurological adverse events. All of these features are demonstrated and supported by the interim data from the regional phase II TRUST-I clinical study. Here we describe the rationale and design of TRUST-II, a global phase II study of taletrectinib in patients with locally advanced/metastatic ROS1+ non-small-cell lung cancer and other ROS1+ solid tumors. The primary end point is confirmed objective response rate. Secondary end points include duration of response, progression-free survival, overall survival and safety. This trial is enrolling patients in North America, Europe and Asia.

The targeted therapies crizotinib and entrectinib are the first options available to treat a type of lung cancer called ROS1 fusion-positive non-small-cell lung cancer (ROS1⁺ NSCLC). However, not all patients with ROS1⁺ NSCLC respond to these drugs. In addition, most patients who take these drugs find their cancer eventually develops resistance and begins to grow again. Patients with disease that has spread (metastasized) to the brain have worse outcomes. Taletrectinib is a new type of targeted therapy that is being developed to treat people who have metastatic ROS1⁺ NSCLC. Data from a regional phase II clinical trial showed that taletrectinib is well tolerated, effective for patients who have never taken a ROS1 targeted therapy and inhibits ROS1⁺ NSCLC for patients whose cancer has developed some types of resistance to these drugs. It has also been shown to treat ROS1⁺ NSCLC tumors that have spread to the brain. This article discusses the rationale and design of a new trial called TRUST-II, which is a global phase II clinical trial looking at how well taletrectinib works and how safe it is. TRUST-II is actively enrolling patients in North America, Europe and Asia. Clinical Trial Registration: NCT04919811 (ClinicalTrials.gov).

Inflammatory myofibroblastic tumors: recent progress and future of targeted therapy.

An inflammatory myofibroblastic tumor is a rare component of bone and soft-tissue sarcomas that has distinct pathological features as a lymphoplasmacytic inflammatory infiltrate. As is the case for other non-small round cell sarcomas, surgical resection remains the standard treatment strategy for inflammatory myofibroblastic tumors, but recurrence is possible. Concerning systemic therapy, the available data for conventional chemotherapy (such as those of doxorubicin-based regimens) are limited, and case reports of anti-inflammatory inflammatory myofibroblastic tumor treatments describe some degree of symptom relief and efficacy against tumor progression. However, as more information about cancer genomics accumulates, the potential for molecularly targeted therapies for inflammatory myofibroblastic tumors has become more promising. Approximately half of inflammatory myofibroblastic tumors harbor anaplastic lymphoma kinase (ALK) fusion genes, and the other half could have potentially targetable fusion genes or mutations such as ROS1, NTRK and RET; case reports demonstrating the clinical efficacy of treatments targeted to inflammatory myofibroblastic tumor have been published, as have several prospective clinical trials. Few drugs are approved for the treatment of inflammatory myofibroblastic tumor, and most of them were approved for tumor-agnostic indications. Drugs that could be used for pediatric indications and dosing in inflammatory myofibroblastic tumor have also not been established. To provide effective targeted therapy for rare diseases such as inflammatory myofibroblastic tumor, it is necessary to obtain clinical evidence by designing and performing clinical trials and to find a path toward regulatory approval.

Brigatinib-associated autoimmune hepatitis: A case report.

INTRODUCTION: Brigatinib is a next-generation anaplastic lymphoma kinase (ALK) inhibitor that targets a wide variety of ALK mutations and ROS1 rearrangements. While pancreatic enzyme elevations due to brigatinib are well known, we wanted to present a case that caused liver toxicity. CASE REPORT: ALK and ROS1 translocations were detected in a 58-year-old patient diagnosed with metastatic lung adenocarcinoma. In the patient who had a good response with brigatinib, more than 5-fold elevation was detected in liver enzymes at the fifth month of treatment. MANAGEMENT & OUTCOME: After excluding other hepatitis factors, the patient was thought to have autoimmune hepatitis, and methylprednisolone was started and liver enzymes were decreased. DISCUSSION: Increased creatine kinase and lipase levels are common side effects associated with brigatinib, while liver toxicity is rare. Autoimmune hepatitis due to brigatinib was considered because of hepatic toxicity that developed in the fifth month of treatment and responded well to steroids.

Alectinib-induced hemolytic anemia.

INTRODUCTION: Alectinib is an oral anaplastic lymphoma kinase tyrosine kinase inhibitor with central nervous system activity. It is currently approved and a preferred first-line option for those with anaplastic lymphoma kinase-positive non-small cell lung cancer. Alectinib has been shown to cause anemia, usually mild. CASE REPORT: We report a case of alectinib-induced hemolytic anemia in a patient receiving alectinib as first-line treatment for anaplastic lymphoma kinase-positive non-small cell lung cancer. MANAGEMENT AND OUTCOME: The patient's dose was reduced from 600 mg twice daily to 450 mg twice daily and further down to 300 mg twice daily and eventually discontinued. At that point, the hemoglobin normalized. DISCUSSION: Our case demonstrates objective evidence for hemolytic anemia induced by alectinib.

Discovery of novel 2-aminopyridine derivatives as ROS1 and ALK dual inhibitors to combat drug-resistant mutants including ROS1G2032R and ALKG1202R.

Clinical treatment by FDA-approved ROS1/ALK inhibitor Crizotinib significantly improved the therapeutic outcomes. However, the emergence of drug resistance, especially driven by acquired mutations, have become an inevitable problem and worsened the clinical effects of Crizotinib. To combat drug resistance, some novel 2-aminopyridine derivatives were designed rationally based on molecular simulation, then synthesised and subjected to biological test. The preferred spiro derivative C01 exhibited remarkable activity against CD74-ROS1G2032R cell with an IC50 value of 42.3 nM, which was about 30-fold more potent than Crizotinib. Moreover, C01 also potently inhibited enzymatic activity against clinically Crizotinib-resistant ALKG1202R, harbouring a 10-fold potency superior to Crizotinib. Furthermore, molecular dynamic disclosed that introducing the spiro group could reduce the steric hindrance with bulky side chain (Arginine) in solvent region of ROS1G2032R, which explained the sensitivity of C01 to drug-resistant mutant. These results indicated a path forward for the generation of anti Crizotinib-resistant ROS1/ALK dual inhibitors.

Cell block-based RNA next generation sequencing for detection of gene fusions in lung adenocarcinoma: An institutional experience.

OBJECTIVE: Targeted therapy is an important part of the treatment of lung adenocarcinoma. Tests for EGFR mutation, ALK, ROS1, RET and NTRK gene fusions are needed to make a treatment decision. These gene fusions are traditionally detected by fluorescence in situ hybridisation (FISH) or immunohistochemistry. In this study, we investigated whether gene fusions in pulmonary adenocarcinoma could be accurately detected by RNA next-generation sequencing (RNA-NGS) and whether cytology cell blocks could be used effectively for this test. METHODS: Archived cytological specimens of lung adenocarcinoma submitted for RNA sequencing between 2019 and 2022 at Fox Chase Cancer Center were retrospectively retrieved. Hybrid capture-based targeted RNA next generation sequencing was used, which covers 507 fusion genes, including ALK, ROS1, RET and NTRKs, irrespective of their partner genes. DNA NGS, FISH and chromosomal microarray analysis were used to confirm the results of the RNA-NGS. RESULTS: A total of 129 lung adenocarcinoma cytology specimens were submitted for molecular testing. Eight of 129 (6.2%) cases were excluded from RNA sequencing as their cell blocks contained inadequate numbers of tumour cells. One case (0.8%) failed to yield adequate RNA. The overall success rate was 93% (120/129). Ten of 120 (8.3%) cytology cases were positive for gene fusions, including 7 ALK, 2 ROS1 fusion genes, and 1 RET fusion gene. Twenty-two cell block cases were also tested for ALK fusion genes using FISH. However, 11 of 22 (50%) failed the testing due to inadequate material. CONCLUSIONS: Cytology cell blocks can be used as the main source of material for molecular testing for lung cancer. Detection of gene fusions by RNA-based NGS on cell blocks is convenient and reliable in daily practice.

Therapeutical Options in ROS1-Rearranged Advanced Non Small Cell Lung Cancer.

ROS proto-oncogene 1 (ROS1) rearrangements occur in 0.9-2.6% of patients with non small cell lung cancer (NSCLC), conferring sensitivity to treatment with specific tyrosine-kinase inhibitors (TKI). Crizotinib, a first-generation TKI, was the first target-therapy approved for the first-line treatment of ROS1-positive NSCLC. Recently, entrectinib, a multitarget inhibitor with an anti-ROS1 activity 40 times more potent than crizotinib and better activity on the central nervous system (CNS), received approval for treatment-naive patients. After a median time-to-progression of 5.5-20 months, resistance mechanisms can occur, leading to tumor progression. Therefore, newer generation TKI with greater potency and brain penetration have been developed and are currently under investigation. This review summarizes the current knowledge on clinicopathological characteristics of ROS1-positive NSCLC and its therapeutic options.

Analysis of CD74 Occurrence in Oncogenic Fusion Proteins.

CD74 is a type II cell surface receptor found to be highly expressed in several hematological and solid cancers, due to its ability to activate pathways associated with tumor cell survival and proliferation. Over the past 16 years, CD74 has emerged as a commonly detected fusion partner in multiple oncogenic fusion proteins. Studies have found CD74 fusion proteins in a range of cancers, including lung adenocarcinoma, inflammatory breast cancer, and pediatric acute lymphoblastic leukemia. To date, there are five known CD74 fusion proteins, CD74-ROS1, CD74-NTRK1, CD74-NRG1, CD74-NRG2α, and CD74-PDGFRB, with a total of 16 different variants, each with unique genetic signatures. Importantly, the occurrence of CD74 in the formation of fusion proteins has not been well explored despite the fact that ROS1 and NRG1 families utilize CD74 as the primary partner for the formation of oncogenic fusions. Fusion proteins known to be oncogenic drivers, including those of CD74, are typically detected and targeted after standard chemotherapeutic plans fail and the disease relapses. The analysis reported herein provides insights into the early intervention of CD74 fusions and highlights the need for improved routine assessment methods so that targeted therapies can be applied while they are most effective.