Emergence and evolution of mosaic penA-60 and penA-237 alleles in a Neisseria gonorrhoeae core genogroup that was historically susceptible to extended spectrum cephalosporins.

Introduction: Neisseria gonorrhoeae (Ng) has successively developed resistance to all previously recommended antimicrobial therapies, with ceftriaxone being the last option for monotherapy of gonorrhea. Global emergence and international spread of the FC428 clone derived mosaic penA-60 allele, associated with highlevel ceftriaxone minimum inhibitory concentrations (MICs) in non FC428 clone Ng lineages, has become an increasing concern. The penA-60 allele carrying Ng was first identified in the U.S. in Las Vegas, Nevada (2019; GCWGS-102723), with a multi-locus sequence type (MLST)-1901 strain, in a non FC428 clone Ng lineage, which is associated with a historically ceftriaxone susceptible core genogroup. Later in 2022, an allele genetically similar to penA-60, mosaic penA-237, was identified in the UK (H22-722) and France (F92) with high-level ceftriaxone MICs and both belonged to MLST-1901. Methods: In this study, we assessed phylogenomic relatedness and antimicrobial resistance (AMR) determinant profiles of these three isolates with high-level ceftriaxone MICs among a global collection of 2,104 genomes belonging to the MLST-1901 core genome cluster group 31, which includes strains separated by a locus threshold of 200 or fewer differences (Ng_cgc_200). Recombination events in and around the penA coding region were catalogued and potential sources of inter species recombinant DNA were also inferred. Results: The global population structure of MLST-1901 core genogroup falls into 4 major lineages. Isolates GCWGS-10723, F92, and H22-722 clustered within Lineage 1, which was dominated by non-mosaic penA-5 alleles. These three isolates formed a clade within Lineage 1 that consisted of isolates from North America and southeast Asia. Neisseria subflava and Neisseria sicca were identified as likely progenitors of two independent recombination events that may have led to the generation of mosaic penA-60 and penA-237, within a possible non-mosaic penA-5 background. Discussions: Our study suggests that there are multiple evolutionary pathways that could generate concerning mosaic penA alleles via homologous recombination of historically susceptible Ng lineages with Neisseria commensals. Enhanced surveillance of gonococcal strains and Neisseria commensals is crucial for understanding of the evolution of AMR, particularly in less-studied regions (e.g., Asia), where high-level ceftriaxone MICs and multi-drug resistance are more prevalent.

Molecular determinants of resurgent sodium currents mediated by Navß4 peptide and A-type FHFs.

Introduction: Resurgent current (INaR ) generated by voltage-gated sodium channels (VGSCs) plays an essential role in maintaining high-frequency firing of many neurons and contributes to disease pathophysiology such as epilepsy and painful disorders. Targeting INaR may present a highly promising strategy in the treatment of these diseases. Navß4 and A-type fibroblast growth factor homologous factors (FHFs) have been identified as two classes of important INaR mediators; however, their receptor sites in VGSCs remain unknown, which hinders the development of novel agents to effectively target INaR . Methods: Navß4 and FHF4A can mediate INaR generation through the amino acid segment located in their C-terminus and N-terminus, respectively. We mainly employed site-directed mutagenesis, chimera construction and whole-cell patch-clamp recording to explore the receptor sites of Navß4 peptide and FHF4A in Nav1.7 and Nav1.8. Results: We show that the receptor of Navß4-peptide involves four residues, N395, N945, F1737 and Y1744, in Nav1.7 DI-S6, DII-S6, and DIV-S6. We show that A-type FHFs generating INaR depends on the segment located at the very beginning, not at the distal end, of the FHF4 N-terminus domain. We show that the receptor site of A-type FHFs also resides in VGSC inner pore region. We further show that an asparagine at DIIS6, N891 in Nav1.8, is a major determinant of INaR generated by A-type FHFs in VGSCs. Discussion: Cryo-EM structures reveal that the side chains of the critical residues project into the VGSC channel pore. Our findings provide additional evidence that Navß4 peptide and A-type FHFs function as open-channel pore blockers and highlight channel inner pore region as a hotspot for development of novel agents targeting INaR .

CRISPR/Cas9 improves targeted knock-in efficiency in Aspergillus oryzae.

Aspergillus oryzae is an important fungus in food and industrial enzyme production. In A. oryzae, targeted knock-in transformation is primarily limited to homologous recombination (HR)-based systems, in which non-homologous end-joining (NHEJ)-disruptant hosts are required. However, preparation of hosts and transformation templates for such systems is laborious, in addition to other disadvantages. In the present study, we examined alternative targeted knock-in mediated by CRISPR/Cas9, in which a microhomology-mediated end-joining (MMEJ) and single-strand annealing (SSA) repair system was employed. This approach enabled the efficient development of targeted knock-in transformants without host preparation using only a short homology template. We conclude that this new method could be applied to facilitate the transformation of A. oryzae, and will make it easier to acquire targeted knock-in transformants, especially from industrially important non-model strains.

Impact of Optimized Ku-DNA Binding Inhibitors on the Cellular and In Vivo DNA Damage Response.

Background: DNA-dependent protein kinase (DNA-PK) is a validated cancer therapeutic target involved in DNA damage response (DDR) and non-homologous end-joining (NHEJ) repair of DNA double-strand breaks (DSBs). Ku serves as a sensor of DSBs by binding to DNA ends and activating DNA-PK. Inhibition of DNA-PK is a common strategy to block DSB repair and improve efficacy of ionizing radiation (IR) therapy and radiomimetic drug therapies. We have previously developed Ku-DNA binding inhibitors (Ku-DBis) that block in vitro and cellular NHEJ activity, abrogate DNA-PK autophosphorylation, and potentiate cellular sensitivity to IR. Results and Conclusions: Here we report the discovery of oxindole Ku-DBis with improved cellular uptake and retained potent Ku-inhibitory activity. Variable monotherapy activity was observed in a panel of non-small cell lung cancer (NSCLC) cell lines, with ATM-null cells being the most sensitive and showing synergy with IR. BRCA1-deficient cells were resistant to single-agent treatment and antagonistic when combined with DSB-generating therapies. In vivo studies in an NSCLC xenograft model demonstrated that the Ku-DBi treatment blocked IR-dependent DNA-PKcs autophosphorylation, modulated DDR, and reduced tumor cell proliferation. This represents the first in vivo demonstration of a Ku-targeted DNA-binding inhibitor impacting IR response and highlights the potential therapeutic utility of Ku-DBis for cancer treatment.

NBS1 dePARylation by NUDT16 is critical for DNA double-strand break repair.

NBS1, a protein linked to the autosomal recessive disorder Nijmegen breakage syndrome, plays an essential role in the DNA damage response and DNA repair. Despite its importance, the mechanisms regulating NBS1 and the impact of this regulation on DNA repair processes remain obscure. In this study, we discovered a new post-translational modification of NBS1, ADP-ribosylation. This modification can be removed by the NUDT16 hydrolase. The loss of NUDT16 results in a reduction of NBS1 protein levels due to NBS1 PARylation-dependent ubiquitination and degradation, which is mediated by the PAR-binding E3 ubiquitin ligase, RNF146. Importantly, ADP-ribosylation of NBS1 is crucial for its localization at DSBs and its involvement in homologous recombination (HR) repair. Additionally, the NUDT16-NBS1 interaction is regulated in response to DNA damage, providing further rationale for NBS1 regulation by NUDT16 hydrolase. In summary, our study unveils the critical role of NUDT16 in governing both the stability of NBS1 and recruitment of NBS1 to DNA double-strand breaks, providing novel insights into the regulation of NBS1 in the HR repair pathway.

The complete mitochondrial genome of Castanopsis carlesii and Castanea henryi reveals the rearrangement and size differences of mitochondrial DNA molecules.

BACKGROUND: Castanopsis carlesii is a dominant tree species in subtropical evergreen broad-leaved forests and holds significant ecological value. It serves as an excellent timber tree species and raw material for cultivating edible fungi. Henry Chinquapin (Castanea henryi) wood is known for its hardness and resistance to water and moisture, making it an exceptional timber species. Additionally, its fruit has a sweet and fruity taste, making it a valuable food source. However, the mitogenomes of these species have not been previously reported. To gain a better understanding of them, this study successfully assembled high-quality mitogenomes of C. carlesii and Ca. henryi for the first time. RESULTS: Our research reveals that the mitochondrial DNA (mtDNA) of C. carlesii exhibits a unique multi-branched conformation, while Ca. henryi primarily exists in the form of two independent molecules that can be further divided into three independent molecules through one pair of long repetitive sequences. The size of the mitogenomes of C. carlesii and Ca. henryi are 592,702 bp and 379,929 bp respectively, which are currently the largest and smallest Fagaceae mitogenomes recorded thus far. The primary factor influencing mitogenome size is dispersed repeats. Comparison with published mitogenomes from closely related species highlights differences in size, gene loss patterns, codon usage preferences, repetitive sequences, as well as mitochondrial plastid DNA segments (MTPTs). CONCLUSIONS: Our study enhances the understanding of mitogenome structure and evolution in Fagaceae, laying a crucial foundation for future research on cell respiration, disease resistance, and other traits in this family.

Development of a prognostic model related to homologous recombination deficiency in glioma based on multiple machine learning.

Background: Despite advances in neuro-oncology, treatments of glioma and tools for predicting the outcome of patients remain limited. The objective of this research is to construct a prognostic model for glioma using the Homologous Recombination Deficiency (HRD) score and validate its predictive capability for glioma. Methods: We consolidated glioma datasets from TCGA, various cancer types for pan-cancer HRD analysis, and two additional glioma RNAseq datasets from GEO and CGGA databases. HRD scores, mutation data, and other genomic indices were calculated. Using machine learning algorithms, we identified signature genes and constructed an HRD-related prognostic risk model. The model's performance was validated across multiple cohorts. We also assessed immune infiltration and conducted molecular docking to identify potential therapeutic agents. Results: Our analysis established a correlation between higher HRD scores and genomic instability in gliomas. The model, based on machine learning algorithms, identified seven key genes, significantly predicting patient prognosis. Moreover, the HRD score prognostic model surpassed other models in terms of prediction efficacy across different cancers. Differential immune cell infiltration patterns were observed between HRD risk groups, with potential implications for immunotherapy. Molecular docking highlighted several compounds, notably Panobinostat, as promising for high-risk patients. Conclusions: The prognostic model based on the HRD score threshold and associated genes in glioma offers new insights into the genomic and immunological landscapes, potentially guiding therapeutic strategies. The differential immune profiles associated with HRD-risk groups could inform immunotherapeutic interventions, with our findings paving the way for personalized medicine in glioma treatment.

Multimodal Spatial Profiling Reveals Immune Suppression and Microenvironment Remodeling in Fallopian Tube Precursors to High-Grade Serous Ovarian Carcinoma.

High-Grade Serous Ovarian Cancer (HGSOC) originates from fallopian tube (FT) precursors. However, the molecular changes that occur as precancerous lesions progress to HGSOC are not well understood. To address this, we integrated high-plex imaging and spatial transcriptomics to analyze human tissue samples at different stages of HGSOC development, including p53 signatures, serous tubal intraepithelial carcinomas (STIC), and invasive HGSOC. Our findings reveal immune modulating mechanisms within precursor epithelium, characterized by chromosomal instability, persistent interferon (IFN) signaling, and dysregulated innate and adaptive immunity. FT precursors display elevated expression of MHC-class I, including HLA-E, and IFN-stimulated genes, typically linked to later-stage tumorigenesis. These molecular alterations coincide with progressive shifts in the tumor microenvironment, transitioning from immune surveillance in early STICs to immune suppression in advanced STICs and cancer. These insights identify potential biomarkers and therapeutic targets for HGSOC interception and clarify the molecular transitions from precancer to cancer.

Crosstalk between BER and NHEJ in XRCC4-Deficient Cells Depending on hTERT Overexpression.

Targeting DNA repair pathways is an important strategy in anticancer therapy. However, the unrevealed interactions between different DNA repair systems may interfere with the desired therapeutic effect. Among DNA repair systems, BER and NHEJ protect genome integrity through the entire cell cycle. BER is involved in the repair of DNA base lesions and DNA single-strand breaks (SSBs), while NHEJ is responsible for the repair of DNA double-strand breaks (DSBs). Previously, we showed that BER deficiency leads to downregulation of NHEJ gene expression. Here, we studied BER's response to NHEJ deficiency induced by knockdown of NHEJ scaffold protein XRCC4 and compared the knockdown effects in normal (TIG-1) and hTERT-modified cells (NBE1). We investigated the expression of the XRCC1, LIG3, and APE1 genes of BER and LIG4; the Ku70/Ku80 genes of NHEJ at the mRNA and protein levels; as well as p53, Sp1 and PARP1. We found that, in both cell lines, XRCC4 knockdown leads to a decrease in the mRNA levels of both BER and NHEJ genes, though the effect on protein level is not uniform. XRCC4 knockdown caused an increase in p53 and Sp1 proteins, but caused G1/S delay only in normal cells. Despite the increased p53 protein, p21 did not significantly increase in NBE1 cells with overexpressed hTERT, and this correlated with the absence of G1/S delay in these cells. The data highlight the regulatory function of the XRCC4 scaffold protein and imply its connection to a transcriptional regulatory network or mRNA metabolism.

The epistatic relationship of Drosophila melanogaster CtIP and Rif1 in homology-directed repair of DNA double-strand breaks.

Double-strand breaks (DSBs) are genotoxic DNA lesions that pose significant threats to genomic stability, necessitating precise and efficient repair mechanisms to prevent cell death or mutations. DSBs are repaired through nonhomologous end-joining (NHEJ) or homology-directed repair (HDR), which includes homologous recombination (HR) and single-strand annealing (SSA). CtIP and Rif1 are conserved proteins implicated in DSB repair pathway choice, possibly through redundant roles in promoting DNA end-resection required for HDR. Although the roles of these proteins have been well-established in other organisms, the role of Rif1 and its potential redundancies with CtIP in Drosophila melanogaster remain elusive. To examine the roles of DmCtIP and DmRif1 in DSB repair, this study employed the direct repeat of white (DR-white) assay, tracking across indels by decomposition (TIDE) analysis, and P{wIw_2 kb 3'} assay to track repair outcomes in HR, NHEJ, and SSA, respectively. These experiments were performed in DmCtIPΔ/Δ single mutants, DmRif1Δ/Δ single mutants, and DmRif1Δ/Δ; DmCtIPΔ/Δ double mutants. This work demonstrates significant defects in both HR and SSA repair in DmCtIPΔ/Δ and DmRif1Δ/Δ single mutants. However, experiments in DmRif1Δ/Δ; DmCtIPΔ/Δ double mutants reveal that DmCtIP is epistatic to DmRif1 in promoting HDR. Overall, this study concludes that DmRif1 and DmCtIP do not perform their activities in a redundant pathway, but rather DmCtIP is the main driver in promoting HR and SSA, most likely through its role in end resection.

Comparative sequencing study of mismatch repair and homology-directed repair genes in endometrial cancer and breast cancer patients from Kazakhstan.

Endometrial cancer has been associated with pathogenic variants in mismatch repair (MMR) genes, especially in the context of the hereditary Lynch Syndrome. More recently, pathogenic variants in genes of homology-directed repair (HDR) have also been suggested to contribute to a subset of endometrial cancers. In the present hospital-based study, we investigated the relative distribution of pathogenic MMR or HDR gene variants in a series of 342 endometrial cancer patients from the Oncology Clinic in Almaty, Kazakhstan. In comparison, we also sequenced 178 breast cancer patients from the same population with the same gene panel. Identified variants were classified according to ClinVar, ESM1b, and AlphaMissense prediction tools. We found 10 endometrial cancer patients (2.9%) carrying pathogenic or likely pathogenic variants in MMR genes (7 MSH6, 1 MSH2, 2 MUTYH), while 14 endometrial cancer patients (4.1%) carried pathogenic variants in HDR genes (4 BRCA2, 3 BRCA1, 3 FANCM, 2 SLX4, 1 BARD1, 1 BRIP1). In the breast cancer series, we found 8 carriers (4.5%) of pathogenic or likely pathogenic variants in MMR genes (2 MSH2, 2 MSH6, 4 MUTYH) while 12 patients (6.7%) harbored pathogenic or likely pathogenic HDR gene variants (5 BRCA1, 3 BRCA2, 1 BRIP1, 1 ERRC4, 1 FANCM, 1 SLX4). One patient who developed breast cancer first and endometrial cancer later carried a novel frameshift variant in MSH6. Our results indicate that MMR and HDR gene variants with predicted pathogenicity occur at substantial frequencies in both breast and endometrial cancer patients from the Kazakh population.

Negative feedback loop in the activation of non-homologous end joining DNA repair pathway in Helicobacter pylori infected patients with gastritis.

This study aimed to investigate the activation of error-prone DNA repair pathway in response to Helicobacter pylori infection. Relative changes in the expression levels of genes involved in the non-homologous end-joining pathway (NHEJ) in H. pylori-infected (Cases) and non-infected patients (Controls) with chronic gastritis were measured. A significant increase in the relative expression level of TP53, and significant decrease in the relative transcription of lncRNA LINP1 and XRCC5 were detected in the case group. The transcription of Lig4 and XRCC6 was increased in the case group, which was not statistically significant. The Spearman's Correlation Coefficient analysis showed a significant positive-correlation between the transcriptional levels of LINP1 and XRCC4/XRCC5/Lig4, and between XRCC5 and TP53/Lig4 both in the case and control groups. Moreover, a significant positive correlation between LinP1 and XRCC6 in the case, and a significant positive correlation between XRCC4 and Lig4, and a negative correlation between TP53 and LinP1/XRCC4/XRCC5 in the control group was detected. Although a relative difference was detected in transcriptional levels of the NHEJ gene mediators, downregulation of LinP1 in H. pylori-infected patients proposed the activation of a negative feedback loop, which may interfere with the NHEJ activity at the early stages of gastritis.

DOT1L: orchestrating methylation-dependent radiotheRAPy responses via BRCA1.

Breast Cancer Type 1 Susceptibility Protein (BRCA)-1 existing in several functionally distinct complexes, promotes DNA repair of DNA double-strand breaks (DSBs). A recent study by Tang and colleagues identifies the lysine methyltransferase Disruptor of Telomeric Silencing 1-Like (DOT1L) involved in modifying Receptor-Associated Protein 80 (RAP80) to promote BRCA1-A complex localization and repair functions at DNA breaks. This study illuminates a potential therapeutic target for cancer radiotherapy.

The DNA Damage Repair Function of Fission Yeast CK1 Involves Targeting Arp8, a Subunit of the INO80 Chromatin Remodeling Complex.

The CK1 family are conserved serine/threonine kinases with numerous substrates and cellular functions. The fission yeast CK1 orthologues Hhp1 and Hhp2 were first characterized as regulators of DNA repair, but the mechanism(s) by which CK1 activity promotes DNA repair had not been investigated. Here, we found that deleting Hhp1 and Hhp2 or inhibiting CK1 catalytic activities in yeast or in human cells increased double-strand breaks (DSBs). The primary pathways to repair DSBs, homologous recombination and nonhomologous end joining, were both less efficient in cells lacking Hhp1 and Hhp2 activity. To understand how Hhp1 and Hhp2 promote DNA damage repair, we identified new substrates of these enzymes using quantitative phosphoproteomics. We confirmed that Arp8, a component of the INO80 chromatin remodeling complex, is a bona fide substrate of Hhp1 and Hhp2 important for DNA repair. Our data suggest that Hhp1 and Hhp2 facilitate DNA repair by phosphorylating multiple substrates, including Arp8.

Template plasmids optimized for deletion of multiple genes in yeast Saccharomyces cerevisiae.

For Saccharomyces cerevisiae, gene knockout is routinely performed by transformation with a linear DNA cassette consisting of a selection marker gene flanked by upstream and downstream sequences homologous to a target gene. Over the years, several plasmid sets containing a variety of selection marker genes have been developed. Targeting fidelity under this strategy was high when performing the first gene knockout in a strain. However, we found that targeting fidelity decreased substantially when performing subsequent gene knockouts. The majority of the transformants were "incorrect," in which the new selection marker gene replaced a pre-existing selection marker gene instead of its intended target. This was caused by the presence of shared regions in the knockout DNA cassettes. To minimize shared regions among knockout cassettes, we developed a set of template plasmids, in which each selection marker open reading frame is flanked by a unique promoter/terminator combination. Our SJZ series templates cover eight selection markers, namely, URA3 (C. a.), TRP1 (K.l.), his5 (S.p.), LEU2 (K.l.), nat, hph, kan, and amdS. When using our templates, targeting fidelity in subsequent gene knockouts was restored to as high as that of the first knockout, with essentially all the transformants being correct. Our templates can therefore bring efficiency improvements in future research projects involving multi-gene knockouts. IMPORTANCE: When knocking out multiple genes in yeast, recombination among selection markers produces a large portion of false-positive transformants. We developed a new set of templates designed to minimize shared regions among selection markers. The use of this new template set resulted in essentially all transformants being correct knockouts.

Prediction of homologous recombination deficiency from routine histology with attention-based multiple instance learning in nine different tumor types.

BACKGROUND: Homologous recombination deficiency (HRD) is recognized as a pan-cancer predictive biomarker that potentially indicates who could benefit from treatment with PARP inhibitors (PARPi). Despite its clinical significance, HRD testing is highly complex. Here, we investigated in a proof-of-concept study whether Deep Learning (DL) can predict HRD status solely based on routine hematoxylin & eosin (H&E) histology images across nine different cancer types. METHODS: We developed a deep learning pipeline with attention-weighted multiple instance learning (attMIL) to predict HRD status from histology images. As part of our approach, we calculated a genomic scar HRD score by combining loss of heterozygosity (LOH), telomeric allelic imbalance (TAI), and large-scale state transitions (LST) from whole genome sequencing (WGS) data of n = 5209 patients across two independent cohorts. The model's effectiveness was evaluated using the area under the receiver operating characteristic curve (AUROC), focusing on its accuracy in predicting genomic HRD against a clinically recognized cutoff value. RESULTS: Our study demonstrated the predictability of genomic HRD status in endometrial, pancreatic, and lung cancers reaching cross-validated AUROCs of 0.79, 0.58, and 0.66, respectively. These predictions generalized well to an external cohort, with AUROCs of 0.93, 0.81, and 0.73. Moreover, a breast cancer-trained image-based HRD classifier yielded an AUROC of 0.78 in the internal validation cohort and was able to predict HRD in endometrial, prostate, and pancreatic cancer with AUROCs of 0.87, 0.84, and 0.67, indicating that a shared HRD-like phenotype occurs across these tumor entities. CONCLUSIONS: This study establishes that HRD can be directly predicted from H&E slides using attMIL, demonstrating its applicability across nine different tumor types.

A Risk Model Developed based on Homologous Recombination Deficiency Genes for Evaluating the Drug Sensitivity and Prognostic Prediction of Lung Adenocarcinoma.

AIM: This study was designed to construct a risk model based on homologous recombination deficiency (HRD) to evaluate the prognosis and drug sensitivity for patients with lung adenocarcinoma (LUAD). BACKGROUND: LUAD is a subtype of lung cancer with unfavorable overall survival (OS) and prognosis. HRD has been widely studied in various tumors, but its role in LUAD has not been fully understood. OBJECTIVE: We aimed to construct an HRD-related risk model for predicting the prognosis and drug sensitivity of patients with LUAD. METHODS: Gene expression data of the LUAD samples were collected from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. We extracted HRD genes from previous literature and performed univariate COX analysis to select those closely associated with LUAD prognosis. ConsensusClusterPlus was employed to stratify the samples in the TCGA-LUAD cohort into different subtypes. A RiskScore model was established applying random forest method. Furthermore, immunotherapy response and drug sensitivity were predicted using Tumor Immune Dysfunction and Exclusion (TIDE) software and pRRophytic R package, respectively. Finally, the clinical features between High- and Low- RiskScore groups were compared. RESULTS: A total of 16 HRD genes relevant to LUAD prognosis were selected and used to classify 3 LUAD clusters (C1, C2, and C3). Specifically, C1, with a lower TIDE score displayed higher immune infiltration and immunotherapy benefit and the optimal OS, while C2 was closely correlated with tumor-relevant pathways and had the worst OS. Finally, 4 HRD genes (RAD51AP1, BRCA1, H2AFX, and FANCL) were determined to develop a RiskScore signature. It was found that a higher RiskScore was related to more advanced stages, worse OS, and tumor development pathways. Additionally, the High-RiskScore group with a higher TIDE score was sensitive to 44 traditional chemotherapy drugs. A nomogram combined with RiskScore exhibited an accurate survival prediction ability. CONCLUSION: The HRD-based RiskScore played a crucial role in LUAD development, showing a strong potential to serve as a prognostic indicator for LUAD. Our findings contributed to the diagnosis of LUAD and its treatment.

Olaparib as maintenance therapy in non resectable pancreatic adenocarcinoma associated with homologous recombination deficiency profile: A French retrospective multicentric AGEO real-world study.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis. The POLO trial showed that olaparib (PARP inhibitor) improved progression-free survival (PFS) but not overall survival (OS), when used as maintenance therapy after ≥ 16 weeks of disease control with first-line platinum-based chemotherapy in patients with germline (g) BRCA 1 or 2 pathogenic variants (PV) metastatic PDAC. However, real-world data on the effectiveness of olaparib are missing. METHODS: Patients with unresectable PDAC associated with somatic (s) or (g)BRCA1/2 and (g)non-BRCA-HRD PV (i.e. other homologous recombination deficiency/HRD genes) who were treated with olaparib between 2020-2023 were included. The primary objective was to describe treatment patterns. Secondary exploratory objectives included OS and PFS in patients treated with olaparib according to the POLO trial or not, OS and PFS in patients with (g)HRD PV-associated PDAC versus (s)PVs, olaparib safety profile and factors associated with olaparib poor outcomes. RESULTS: Among 85 patients, 45.9 % received olaparib as defined by the POLO trial. No difference in OS and PFS was observed between patients who received olaparib according to the POLO trial versus not. Patients with (g)HRD PV-associated PDAC had better OS compared to others (22.3 versus 10.5 months, p = 0.038). Factors associated with olaparib poor outcomes included a high neutrophil-to-lymphocyte ratio and the use of olaparib outside the recommendations of the POLO trial. Few grade ≥ 3 adverse events were reported (9.4 %). CONCLUSION: Patients with (g)HRD PV-associated PDAC had longer OS than those with (s)HRD PV. Olaparib use beyond the scope of the POLO trial was associated with poor outcomes.

Exploring the impact of durvalumab on biliary tract cancer: insights from real-world clinical data.

INTRODUCTION: This study assesses the effectiveness of durvalumab with platinum and gemcitabine for biliary tract cancers (BTC). It aims to confirm the TOPAZ-1 trial results in a real-world context and explore the link between BTC molecular profiles and patient outcomes. METHODS: A retrospective analysis was conducted on 102 BTC patients treated with durvalumab, platinum, and gemcitabine at five cancer centers in Austria and one in Germany from 2022 to 2024. Molecular profiling used targeted DNA and RNA assays. Clinical endpoints, including progression-free survival (PFS) and overall survival (OS), were assessed using log-rank tests and Cox regression, with correlations to second-line molecular-targeted therapies. RESULTS: Among 102 patients, 60.8% had intrahepatic cholangiocarcinoma. The treatment achieved a disease control rate of 71.57% and an overall response rate of 35.11%. Median PFS was 6.51 months, and OS was 13.61 months. Patients under 65 had significantly better OS. Alterations in chromatin remodeling or homologous recombination repair genes were not predictive of survival benefit (HR: 0.45; p = 0.851 and HR: 1.63; p = 0.26, respectively). Patients with molecular-informed second-line therapy showed a trend toward survival benefit (HR: 0.23; p = 0.052). CONCLUSION: This study confirms the phase 3 trial results of durvalumab with platinum and gemcitabine, providing a substantial real-world dataset with detailed molecular characterization. No specific patient subgroup showed a markedly better response to durvalumab based on conventional NGS panels. Further research is needed to explore the link between immunotherapy responses and molecular subgroups.