Two important factors that contribute to resistance to immune checkpoint inhibitors (ICI) are an immune-suppressive microenvironment and limited antigen presentation by tumor cells. In this study, we examine whether inhibition of the methyltransferase enhancer of zeste homolog 2 (EZH2) can increase ICI response in lung squamous cell carcinomas (LSCC). Our in vitro experiments using two-dimensional human cancer cell lines as well as three-dimensional murine and patient-derived organoids treated with two inhibitors of the EZH2 plus IFNγ showed that EZH2 inhibition leads to expression of both MHC class I and II (MHCI/II) expression at both the mRNA and protein levels. Chromatin immunoprecipitation sequencing confirmed loss of EZH2-mediated histone marks and gain of activating histone marks at key loci. Furthermore, we demonstrate strong tumor control in models of both autochthonous and syngeneic LSCC treated with anti-PD1 immunotherapy with EZH2 inhibition. Single-cell RNA sequencing and immune cell profiling demonstrated phenotypic changes toward more tumor suppressive phenotypes in EZH2 inhibitor–treated tumors. These results indicate that EZH2 inhibitors could increase ICI responses in patients undergoing treatment for LSCC. Significance: The data described here show that inhibition of the epigenetic enzyme EZH2 allows derepression of multiple immunogenicity factors in LSCC, and that EZH2 inhibition alters myeloid cells in vivo. These data support clinical translation of this combination therapy for treatment of this deadly tumor type.

Background: Generative artificial intelligence (GenAI) models are increasingly used for medical information retrieval, due to their accessibility and efficiency. However, the accuracy and readability of their responses, specifically for upper gastrointestinal cancers, remain inadequately evaluated. This gap highlights the need for rigorous assessment to ensure reliable patient education and clinical integration. Objective: This study aimed to assess the accuracy and readability of responses generated by four prominent GenAI models (Kimi, DeepSeek, ChatGPT, and Gemini) when addressing patient-focused questions related to esophageal and gastric cancers. Methods: Twenty-five standardized medical questions about esophageal and gastric cancer covering domains of disease definition, treatment and management were posed to each model. Responses were assessed by four oncologists for accuracy by a 5-point Likert scale and analyzed for readability using Flesch–Kincaid Reading Ease, Flesch–Kincaid Grade Level, and SMOG metrics. High-interest questions for patients were identified via questionnaires. Results: Comparing the accuracy of GenAI-generated responses, DeepSeek achieved the highest overall accuracy score and outperformed other models in questions about definitions and treatments, while ChatGPT excelled in management-related inquiries. In subgroup analysis, GenAI models exhibited higher accuracy in answering definition and management questions, which patients preferred to inquire, compared with questions about cancer therapies. The responses produced by all models required a reading capacity from 11th-grade to college level. Conclusions: This study revealed that in this comparative evaluation application of GenAI models, DeepSeek provides the most accurate responses for upper GI cancer inquiries about definition and treatment, while ChatGPT showed superiority in management-related questions. However, all models generate texts requiring advanced reading levels, highlighting a need for readability optimization without compromising accuracy. GenAI shows promise for patient education but requires rigorous validation for clinical integration.

While poly (adenosine diphosphate-ribose) polymerase inhibitors (PARPi) have achieved specific clinical benefits in a subset of pancreatic ductal adenocarcinoma (PDAC) patients, the potential role of the PARPi niraparib in PDAC necessitates further exploration. In this study, we demonstrated that Niraparib exhibited a pronounced inhibitory effect on autophagy in PDAC both in vitro and in vivo. Mechanistically, this inhibition was primarily attributed to niraparib's ability to disrupt the fusion process between autophagosomes and lysosomes, while potentially exerting a relatively minor impact on the initial stage of autophagy. The blockade effect observed may be mediated via modulation of the ERK signaling pathway, and this effect can be mitigated by the application of an ERK inhibitor (FR180204). Notably, the combined treatment regimen of niraparib and gemcitabine failed to elicit the anticipated synergistic effects in wild-type PANC-1 cells, instead exhibiting pronounced antagonistic interactions. However, in gemcitabine-resistant PANC-1 cells, the combination of niraparib and gemcitabine exhibited modest additive effects. Furthermore, niraparib demonstrated a heightened cytotoxic potency against gemcitabine-resistant PANC-1 cells compared to wild-type PANC-1 cells, both in vitro and in vivo. Our research established that niraparib inhibits late-stage autophagy in PDAC, potentially representing a valuable salvage therapy for gemcitabine-resistant PDAC. Further clinical studies are justified.

Two important factors that contribute to resistance to immune checkpoint inhibitors (ICI) are an immune-suppressive microenvironment and limited antigen presentation by tumor cells. In this study, we examine whether inhibition of the methyltransferase enhancer of zeste homolog 2 (EZH2) can increase ICI response in lung squamous cell carcinomas (LSCC). Our in vitro experiments using two-dimensional human cancer cell lines as well as three-dimensional murine and patient-derived organoids treated with two inhibitors of the EZH2 plus IFNγ showed that EZH2 inhibition leads to expression of both MHC class I and II (MHCI/II) expression at both the mRNA and protein levels. Chromatin immunoprecipitation sequencing confirmed loss of EZH2-mediated histone marks and gain of activating histone marks at key loci. Furthermore, we demonstrate strong tumor control in models of both autochthonous and syngeneic LSCC treated with anti-PD1 immunotherapy with EZH2 inhibition. Single-cell RNA sequencing and immune cell profiling demonstrated phenotypic changes toward more tumor suppressive phenotypes in EZH2 inhibitor–treated tumors. These results indicate that EZH2 inhibitors could increase ICI responses in patients undergoing treatment for LSCC.Significance:The data described here show that inhibition of the epigenetic enzyme EZH2 allows derepression of multiple immunogenicity factors in LSCC, and that EZH2 inhibition alters myeloid cells in vivo. These data support clinical translation of this combination therapy for treatment of this deadly tumor type.

Supplementary Figure 5 shows additional analysis of tumors from EZH2 inhibition and anti-PD1 treated mice.

EZH2 inhibition allows upregulation of MHCI and MHCII in 2D human LSCC cell lines. A, Schematic for proposed mechanism: Inhibition of EZH2 methyltransferase activity by the drugs GSK126 or EPZ6438 will lead to derepression of antigen presentation genes that can then be more effectively activated by IFNγ. B, qRT-PCR in the indicated four human lung cancer cell lines treated for 7 days with vehicle or 5 µmol/L EZH2 inhibition with 20 ng/mL IFNγ added on day 5 for the genes B2M, HLA-A, CIITA, and HLA-DRA, mean ± SEM is graphed, n = 4 individual cultures, *, P < 0.04; **, P < 0.008; ***, P < 0.0009; ****, P < 0.0001 by one-way ANOVA with pairwise comparisons and Holm-Šídák post hoc test. C, Flow cytometry analysis of indicated four human lung cancer cell lines treated for 7 days with vehicle or 5 µmol/L EZH2 inhibition with 20 ng/mL IFNγ added on day 5 for the cell surface proteins HLA-A,B,C and HLA-DR; mean ± SEM is graphed; n = 4 individual cultures; *, P < 0.04; **, P < 0.006; ***, P < 0.0009; ****, P < 0.0001 by one-way ANOVA with pairwise comparisons and Holm-Šídák's post hoc test. Representative histograms from HCC15 cell lines are shown, G = GSK126, E = EPZ6438, I = IFNγ, I+G = IFNγ+GSK126, and I+E = IFNγ+EPZ6438. D, Western blotting of A549 and HCC15 cell lines treated for 7 days with vehicle or 5 µmol/L EZH2 inhibition with 20 ng/mL IFNγ added on day 5 for the proteins B2M, HLA-DR, DQ, DP, EZH2, H3K27me3 and total histone H3. Data are representative of two individual cultures. See also Supplementary Fig. S1.