Loss of the Fanconi anemia-associated protein NIPA causes bone marrow failure

Unraveling the Potential of ALK-Targeted Therapies in Non-Small Cell Lung Cancer: Comprehensive Insights and Future Directions

Background and Objective: This review comprehensively explores the intricate landscape of anaplastic lymphoma kinase (ALK), focusing specifically on its pivotal role in non-small cell lung cancer (NSCLC). Tracing ALK's discovery, from its fusion with nucleolar phosphoprotein (NPM)-1 in anaplastic large cell non-Hodgkin's lymphoma (ALCL) in 1994, the review elucidates the subsequent impact of ALK gene alterations in various malignancies, including inflammatory myofibroblastoma and NSCLC. Approximately 3-5% of NSCLC patients exhibit complex ALK rearrangements, leading to the approval of six ALK-tyrosine kinase inhibitors (TKIs) by 2022, revolutionizing the treatment landscape for advanced metastatic ALK + NSCLC. Notably, second-generation TKIs such as alectinib, ceritinib, and brigatinib have emerged to address resistance issues initially associated with the pioneer ALK-TKI, crizotinib. Methods: To ensure comprehensiveness, we extensively reviewed clinical trials on ALK inhibitors for NSCLC by 2023. Additionally, we systematically searched PubMed, prioritizing studies where the terms "ALK" AND "non-small cell lung cancer" AND/OR "NSCLC" featured prominently in the titles. This approach aimed to encompass a spectrum of relevant research studies, ensuring our review incorporates the latest and most pertinent information on innovative and alternative therapeutics for ALK + NSCLC. Key Content and Findings: Beyond exploring the intricate details of ALK structure and signaling, the review explores the convergence of ALK-targeted therapy and immunotherapy, investigating the potential of immune checkpoint inhibitors in ALK-altered NSCLC tumors. Despite encouraging preclinical data, challenges observed in trials assessing combinations such as nivolumab-crizotinib, mainly due to severe hepatic toxicity, emphasize the necessity for cautious exploration of these novel approaches. Additionally, the review explores innovative directions such as ALK molecular diagnostics, ALK vaccines, and biosensors, shedding light on their promising potential within ALK-driven cancers. Conclusions: This comprehensive analysis covers molecular mechanisms, therapeutic strategies, and immune interactions associated with ALK-rearranged NSCLC. As a pivotal resource, the review guides future research and therapeutic interventions in ALK-targeted therapy for NSCLC.

Gene editing of hematopoietic stem cells restores T-cell response in familial hemophagocytic lymphohistiocytosis

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory disorder characterized by a life-threatening cytokine storm and immunopathology. Familial HLH type 3 (FHL3) accounts for approximately 30% of all inborn HLH cases worldwide. It is caused by mutations in the UNC13D gene that result in impaired degranulation of cytotoxic vesicles and hence compromised T-cell- and natural killer-cell-mediated killing. Current treatment protocols, including allogeneic hematopoietic stem cell (HSC) transplantation, still show high mortality.

OBJECTIVE

We sought to develop and evaluate a curative genome editing strategy in the preclinical FHL3 Jinx mouse model. Jinx mice harbor a cryptic splice donor site in Unc13d intron 26 and develop clinical symptoms of human FHL3 upon infection with lymphocytic choriomeningitis virus (LCMV).

METHODS

We employed clustered regularly interspaced short palindromic repeats (CRISPR)-Cas technology to delete the disease-causing mutation in HSCs and transplanted Unc13d-edited stem cells into busulfan-conditioned Jinx recipient mice. Safety studies included extensive genotyping and chromosomal aberrations analysis by single targeted linker-mediated PCR sequencing (CAST-Seq)-based off-target analyses. Cure from HLH predisposition was assessed by LCMV infection.

RESULTS

Hematopoietic cells isolated from transplanted mice revealed efficient gene editing (>95%), polyclonality of the T-cell receptor repertoire, and neither signs of off-target effects nor leukemogenesis. Unc13d transcription levels of edited and wild-type cells were comparable. While LCMV challenge resulted in acute HLH in Jinx mice transplanted with mock-edited HSCs, Jinx mice grafted with Unc13d-edited cells showed rapid virus clearance and protection from HLH.

CONCLUSIONS

Our study demonstrates that transplantation of CRISPR-Cas edited HSCs supports the development of a functional polyclonal T-cell response in the absence of genotoxicity-associated clonal outgrowth.

DNA damage and repair in the hematopoietic system

Although hematopoietic stem cells (HSCs) in the bone marrow are in a state of quiescence, they harbor the self-renewal capacity and the pluripotency to differentiate into mature blood cells when needed, which is key to maintain hematopoietic homeostasis. Importantly, HSCs are characterized by their long lifespan ( e. g., up to 60 months for mice), display characteristics of aging, and are vulnerable to various endogenous and exogenous genotoxic stresses. Generally, DNA damage in HSCs is endogenous, which is typically induced by reactive oxygen species (ROS), aldehydes, and replication stress. Mammalian cells have evolved a complex and efficient DNA repair system to cope with various DNA lesions to maintain genomic stability. The repair machinery for DNA damage in HSCs has its own characteristics. For instance, the Fanconi anemia (FA)/BRCA pathway is particularly important for the hematopoietic system, as it can limit the damage caused by DNA inter-strand crosslinks, oxidative stress, and replication stress to HSCs to prevent FA occurrence. In addition, HSCs prefer to utilize the classical non-homologous end-joining pathway, which is essential for the V(D)J rearrangement in developing lymphocytes and is involved in double-strand break repair to maintain genomic stability in the long-term quiescent state. In contrast, the base excision repair pathway is less involved in the hematopoietic system. In this review, we summarize the impact of various types of DNA damage on HSC function and review our knowledge of the corresponding repair mechanisms and related human genetic diseases.

NIPA (Nuclear Interaction Partner of ALK) Is Crucial for Effective NPM-ALK Mediated Lymphomagenesis

The NPM-ALK fusion kinase is expressed in 60% of systemic anaplastic large-cell lymphomas (ALCL). A Nuclear Interaction Partner of ALK (NIPA) was identified as a binding partner of NPM-ALK. To identify the precise role of NIPA for NPM-ALK-driven lymphomagenesis, we investigated various NPM-ALK+ cell lines and mouse models. Nipa deletion in primary mouse embryonic fibroblasts resulted in reduced transformation ability and colony formation upon NPM-ALK expression. Downregulating NIPA in murine NPM-ALK+ Ba/F3 and human ALCL cells decreased their proliferation ability and demonstrated synergistic effects of ALK inhibition and NIPA knockdown. Comprehensive in vivo analyses using short- and long-latency transplantation mouse models with NPM-ALK+ bone marrow (BM) revealed that Nipa deletion inhibited NPM-ALK-induced tumorigenesis with prolonged survival and reduced spleen colonies. To avoid off-target effects, we combined Nipa deletion and NPM-ALK expression exclusively in T cells using a lineage-restricted murine ALCL-like model resembling human disease: control mice died from neoplastic T-cell infiltration, whereas mice transplanted with Lck-CreTG/wtNipaflox/flox NPM-ALK+ BM showed significantly prolonged survival. Immunophenotypic analyses indicated a characteristic ALCL-like phenotype in all recipients but revealed fewer “stem-cell-like” features of Nipa-deficient lymphomas compared to controls. Our results identify NIPA as a crucial player in effective NPM-ALK-driven ALCL-like disease in clinically relevant murine and cell-based models.

ZC3HC1 Is a Novel Inherent Component of the Nuclear Basket, Resident in a State of Reciprocal Dependence with TPR

The nuclear basket (NB) scaffold, a fibrillar structure anchored to the nuclear pore complex (NPC), is regarded as constructed of polypeptides of the coiled-coil dominated protein TPR to which other proteins can bind without contributing to the NB's structural integrity. Here we report vertebrate protein ZC3HC1 as a novel inherent constituent of the NB, common at the nuclear envelopes (NE) of proliferating and non-dividing, terminally differentiated cells of different morphogenetic origin. Formerly described as a protein of other functions, we instead present the NB component ZC3HC1 as a protein required for enabling distinct amounts of TPR to occur NB-appended, with such ZC3HC1-dependency applying to about half the total amount of TPR at the NEs of different somatic cell types. Furthermore, pointing to an NB structure more complex than previously anticipated, we discuss how ZC3HC1 and the ZC3HC1-dependent TPR polypeptides could enlarge the NB's functional repertoire.

Role of gene therapy in Fanconi anemia: A systematic and literature review with future directions

Gene therapy (GT) has been reported to improve bone marrow function in individuals with Fanconi anemia (FA); however, its clinical application is still in the initial stages. We conducted this systematic review, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, to assess the long-term safety and clinical outcomes of GT in FA patients. Electronic searches from PubMed, Web of Science, Cochrane Library, and Google Scholar were conducted and full texts of articles meeting our inclusion criteria were reviewed. Three clinical trials were included, with a total of nine patients and mean age of 10.7 ± 5.7 years. All patients had lentiviral-mediated GT. A 1-year follow-up showed stabilization in blood lineages, without any serious adverse effects from GT. A metaregression analysis could not be conducted, as very little long-term follow-up data of patients was observed, and the median survival rate could not be calculated. Thus, we can conclude that GT seems to be a safe procedure in FA; however, further research needs to be conducted on the longitudinal clinical effects of GT in FA, for a better insight into its potential to become a standard form of treatment.