A Single-Cell Atlas of Tumor-Infiltrating Immune Cells in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies with limited treatment options. To guide the design of more effective immunotherapy strategies, mass cytometry was employed to characterize the cellular composition of the PDAC-infiltrating immune cells. The expression of 33 protein markers was examined at the single-cell level in more than two million immune cells from four types of clinical samples, including PDAC tumors, normal pancreatic tissues, chronic pancreatitis tissues, and peripheral blood. Based on the analyses, we identified 23 distinct T-cell phenotypes, with some cell clusters exhibiting aberrant frequencies in the tumors. Programmed cell death protein 1 (PD-1) was extensively expressed in CD4+ and CD8+ T cells and coexpressed with both stimulatory and inhibitory immune markers. In addition, we observed elevated levels of functional markers, such as CD137L and CD69, in PDAC-infiltrating immune cells. Moreover, the combination of PD-1 and CD8 was used to stratify PDAC tumors from The Cancer Genome Atlas database into three immune subtypes, with S1 (PD-1+CD8+) exhibiting the best prognosis. Further analysis suggested distinct molecular mechanisms for immune exclusion in different subtypes. Taken together, the single-cell protein expression data depicted a detailed cell atlas of the PDAC-infiltrating immune cells and revealed clinically relevant information regarding useful cell phenotypes and targets for immunotherapy development.

Integrated Proteomics and Single-Cell Mass Cytometry Analysis Dissects the Immune Landscape of Ankylosing Spondylitis.

Mass cytometry is a powerful single-cell technology widely adopted to depict immune cell heterogeneity in different contexts. However, this method is only capable of examining several dozens of proteins simultaneously and requires a prior knowledge of the markers to be analyzed. Here we propose that the integration of mass cytometry with shot-gun proteomics may serve as a valuable tool to achieve an in-depth understanding of the immune system. By implementing such a strategy, we investigated the immune landscape of ankylosing spondylitis (AS), a chronic inflammatory arthritis with unclear etiology. The proteome alteration in peripheral blood mononuclear cells (PBMCs) was investigated by quantitative proteomics, and then mass cytometry analysis was conducted to decipher the immunome by considering the signaling molecules identified with differential expression by proteomics. As a result, we identified a wide spectrum of proteins dysregulated in AS, e.g., upregulation of glycolytic enzymes, downregulation of lipid transporters, and dysregulation of chemokine signaling molecules involved in proinflammatory cytokine production and leucocyte migration. Moreover, the single-cell analysis showed the upregulation of chemokine signaling regulators in subclusters of both innate and adaptive immune cells in AS. In addition, correlation analysis unveiled the interplay among Phenograph-identified subclusters of monocytes, CD4+ T cells, and CD8+ T cells. Taken together, our findings demonstrated that the integration of mass spectrometry-based proteomics and single-cell mass cytometry may serve as a useful tool to reveal clinically relevant information regarding useful targets and cellular phenotypes that could be further exploited to develop novel therapeutic strategies.

Low-dose anlotinib confers improved survival in combination with immune checkpoint inhibitor in advanced non-small cell lung cancer patients.

BACKGROUND: Anti-angiogenic drugs increase anti-tumor efficacy of immune checkpoint inhibitors (ICIs). However, the optimal dose of anti-angiogenic drugs remains unclear. METHODS: We retrospectively analyzed efficacy and safety data from patients diagnosed with advanced or metastatic non-small cell lung cancer (NSCLC) that received PD-1 blockade with low-doses of anlotinib, a highly selective receptor tyrosine kinase inhibitor mainly targeting vascular endothelial growth factor receptors, as second or later line therapy. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), overall response rate (ORR), disease control rate (DCR), and safety profile. Univariate and multivariate analyses were used to identify prognostic factors. RESULTS: A total of 40 eligible patients were included. The median PFS was 11.4 months. The median OS of the entire cohort was 27.0 months. ORR was achieved in 16 patients (40.0%) and DCR was maintained in 33 patients (82.5%). The overall incidence of adverse events (AEs) was 52.5%, and the most common all grade AE was gastrointestinal reactions, which occurred in four patients (10.0%). Treatment-related grade 3/4 toxicity was observed in one patient (2.5%). Conclusions Low-dose anlotinib may be an effective and well-tolerated anti-angiogenesis partner for combination therapy with ICIs in second-line and later settings for advanced NSCLC.

Luminescent gold nanoclusters for in vivo tumor imaging.

Fluorescent gold nanoclusters (AuNCs) are emerging as novel imaging contrast agents. These molecules offer excellent prospects for non-invasive tumor diagnosis strategies because of their ultra-small size, tunable emissions from the visible to the near-infrared range, excellent biocompatibility, and suitable pharmacokinetic properties. In this tutorial review, we introduce the physiological features of the tumor microenvironment, followed by a description of AuNC pharmacokinetics. Next, we outline the strategies used to deliver AuNCs specifically to tumor tissues for in vivo tumor imaging. Finally, examples are presented to highlight the application potential of AuNCs for in vivo tumor imaging.

A comparative study of sampling methods in the detection of esophageal cancer-related microbiota.

Esophageal cancer (EC) is a multifaceted disease. Our understanding of the involvement of esophageal microbiota in its pathogenesis and progression is limited, which is due to the lack of proper endoscopic sampling methods. Hereby, we conducted a comparative analysis of paired samples obtained through endoscopic brushing and cytosponge, aiming at assessing the feasibility of using cytosponge as a minimally invasive sampling way for studying esophageal microbiota. Our findings suggest that cytosponge sampling yielded significantly superior community richness and diversity compared to endoscopic brushing in both controls (non-cancerous) and EC individuals. The analysis of beta-diversity revealed distinct microbial community pattern in the genus diversity between the two sampling methods, underscoring the importance of selecting appropriate sampling methods to effectively characterize the esophageal microbiota. Specifically, Lactococcus and Serratia showed higher abundance in the samples collected by endoscopic brushing, while Alloprevotella and Leptotrichia were more enriched in the samples collected by cytosponge. These differences in dominant microbes were associated with metabolic pathways that particularly were related to host inflammation, such as pyruvate and glucose metabolisms. Notably, the phylogenetic levels of the microbiota indicated varied explanatory power for different detection purposes. This study underscores the substantial impact of sampling method selection on the acquisition of esophageal microbiota associated with the EC development, encompassing considerations of both abundance and diversity. This highlights the significance of selecting an appropriate sampling method for investigating the esophageal microbial status and studying the micro-environment in EC-related individuals. IMPORTANCE: This study addresses a critical issue in esophageal cancer study by comparing two different sampling methods, endoscopic brushing and cytosponge, for investigating the esophageal microbiota. Our work highlights the suitability of the cytosponge technique as a minimally invasive sampling method for studying the esophageal microbiota and emphasizes the importance of selecting an appropriate sampling method to characterize the microbial community. Our findings have significant implications for advancing the understanding of the role of the esophageal microbiota in cancer development and will inform future research and clinical approaches in this field.

METTL1-mediated tRNA m7G methylation and translational dysfunction restricts breast cancer tumorigenesis by fueling cell cycle blockade.

BACKGROUND: RNA modifications of transfer RNAs (tRNAs) are critical for tRNA function. Growing evidence has revealed that tRNA modifications are related to various disease processes, including malignant tumors. However, the biological functions of methyltransferase-like 1 (METTL1)-regulated m7G tRNA modifications in breast cancer (BC) remain largely obscure. METHODS: The biological role of METTL1 in BC progression were examined by cellular loss- and gain-of-function tests and xenograft models both in vitro and in vivo. To investigate the change of m7G tRNA modification and mRNA translation efficiency in BC, m7G-methylated tRNA immunoprecipitation sequencing (m7G tRNA MeRIP-seq), Ribosome profiling sequencing (Ribo-seq), and polysome-associated mRNA sequencing were performed. Rescue assays were conducted to decipher the underlying molecular mechanisms. RESULTS: The tRNA m7G methyltransferase complex components METTL1 and WD repeat domain 4 (WDR4) were down-regulated in BC tissues at both the mRNA and protein levels. Functionally, METTL1 inhibited BC cell proliferation, and cell cycle progression, relying on its enzymatic activity. Mechanistically, METTL1 increased m7G levels of 19 tRNAs to modulate the translation of growth arrest and DNA damage 45 alpha (GADD45A) and retinoblastoma protein 1 (RB1) in a codon-dependent manner associated with m7G. Furthermore, in vivo experiments showed that overexpression of METTL1 enhanced the anti-tumor effectiveness of abemaciclib, a cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitor. CONCLUSION: Our study uncovered the crucial tumor-suppressive role of METTL1-mediated tRNA m7G modification in BC by promoting the translation of GADD45A and RB1 mRNAs, selectively blocking the G2/M phase of the cell cycle. These findings also provided a promising strategy for improving the therapeutic benefits of CDK4/6 inhibitors in the treatment of BC patients.

An EBV-related CD4 TCR immunotherapy inhibits tumor growth in an HLA-DP5+ nasopharyngeal cancer mouse model.

Adoptive transfer of T cell receptor-engineered T cells (TCR-T) is a promising strategy for immunotherapy against solid tumors. However, the potential of CD4+ T cells in mediating tumor regression has been neglected. Nasopharyngeal cancer is consistently associated with EBV. Here, to evaluate the therapeutic potential of CD4 TCR-T in nasopharyngeal cancer, we screened for CD4 TCRs recognizing EBV nuclear antigen 1 (EBNA1) presented by HLA-DP5. Using mass spectrometry, we identified EBNA1567-581, a peptide naturally processed and presented by HLA-DP5. We isolated TCR135, a CD4 TCR with high functional avidity, that can function in both CD4+ and CD8+ T cells and recognizes HLA-DP5-restricted EBNA1567-581. TCR135-transduced T cells functioned in two ways: directly killing HLA-DP5+EBNA1+ tumor cells after recognizing EBNA1 presented by tumor cells and indirectly killing HLA-DP5-negative tumor cells after recognizing EBNA1 presented by antigen-presenting cells. TCR135-transduced T cells preferentially infiltrated into the tumor microenvironment and significantly inhibited tumor growth in xenograft nasopharyngeal tumor models. Additionally, we found that 62% of nasopharyngeal cancer patients showed 50%-100% expression of HLA-DP on tumor cells, indicating that nasopharyngeal cancer is well suited for CD4 TCR-T therapy. These findings suggest that TCR135 may provide a new strategy for EBV-related nasopharyngeal cancer immunotherapy in HLA-DP5+ patients.

Microbiome changes in esophageal cancer: implications for pathogenesis and prognosis.

Esophageal cancer (EC) is an aggressive malignancy with a poor prognosis. Various factors, including dietary habits, and antacid and antibiotic use, have been shown to influence the esophageal microbiome. Conversely, enrichment and diversity of the esophageal microbiome can also impact its function. Recent studies have revealed prevalent changes in the esophageal microbiome among patients with EC, thus suggesting the potential contribution of the esophageal microbiome to EC development. Additionally, distinct microbiome compositions have been observed in patients with different responses to radiotherapy and chemotherapy, indicating the role of the esophageal microbiome in modulating treatment outcomes. In this review, we have examined previous studies on the esophageal microbiome in healthy individuals and patients with EC or other esophageal diseases, with a focus on identifying microbial communities associated with EC pathogenesis and prognosis. Understanding the role of the microbiome in EC may aid in early detection and optimized treatment strategies, ultimately leading to better outcomes for patients.

When N7-methyladenosine modification meets cancer: Emerging frontiers and promising therapeutic opportunities.

N7-methylguanosine (m7G) methylation, one of the most common RNA modifications in eukaryotes, has recently gained considerable attention. The biological functions of m7G modification in RNAs, including tRNA, rRNA, mRNA, and miRNA, remain largely unknown in human diseases. Owing to rapid advances in high-throughput technologies, increasing evidence suggests that m7G modification plays a critical role in cancer initiation and progression. As m7G modification and hallmarks of cancer are inextricably linked together, targeting m7G regulators may provide new possibilities for future cancer diagnoses and potential intervention targets. This review summarizes various detection methods for m7G modification, recent advances in m7G modification and tumor biology regarding their interplay and regulatory mechanisms. We conclude with an outlook on the future of diagnosing and treating m7G-related diseases.

EIF4A3-mediated circ_0042881 activates the RAS pathway via miR-217/SOS1 axis to facilitate breast cancer progression.

Breast cancer (BC) is one of the most frequent cancer-related deaths in women worldwide. Studies have shown the potential impact of circRNAs in multiple human tumorigeneses. Research on the vital signaling pathways and therapeutic targets of circRNAs is indispensable. Here, we aimed to investigate the clinical implications and underlying mechanisms of circ_0042881 in BC. RT-qPCR validated circ_0042881 was notably elevated in BC tissues and plasma, and closely associated with BC clinicopathological features. Functionally, circ_0042881 significantly accelerated the proliferation, migration, and invasion of BC cells in vitro and tumor growth and metastasis in vivo. Mechanistically, circ_0042881 promoted BC progression by sponging miR-217 to relieve its inhibition effect in son of sevenless 1 (SOS1), which further activated RAS protein and initiated downstream signaling cascades, including MEK/ERK pathway and PI3K/AKT pathway. We also demonstrated that treatment of BAY-293, an inhibitor of SOS1 and RAS interaction, attenuated BC progression induced by circ_0042881 overexpression. Furthermore, Eukaryotic initiation factor 4A-III (EIF4A3) could facilitate circ_0042881 circularization. Altogether, we proposed a novel signaling network in which circ_0042881, induced by EIF4A3, influences the process of BC tumorigenesis and metastasis by miR-217/SOS1 axis.

N6-methyladenosine modification of REG1α facilitates colorectal cancer progression via ß-catenin/MYC/LDHA axis mediated glycolytic reprogramming.

Aerobic glycolysis has been considered as a hallmark of colorectal cancer (CRC). However, the potential functional regulators of glycolysis in CRC remains to be elucidated. In the current study, we found that Regenerating islet-derived protein 1-alpha (REG1α) was significantly increased in both CRC tissues and serum, and positively associated with CRC patients' lymph node metastasis, advanced tumor stage, and unfavorable prognosis. Ectopic expression of REG1α contributed to various tumorigenic properties, including cell proliferation, cell cycle, migration, invasion, and glycolysis. In contrast, REG1α deficiency in CRC cells attenuated malignant properties and glucose metabolism. Mechanically, REG1α promoted CRC proliferation and metastasis via ß-catenin/MYC axis-mediated glycolysis upregulation. Moreover, the malignant behaviors governed by REG1α could be effectively abolished by silencing of Wnt/ß-catenin/MYC axis or glycolysis process using specific inhibitors. Besides, REG1α expression was mediated by METTL3 in an m6A-dependent manner. Overall, our work defines a novel regulatory model of the METTL3/REG1α/ß-catenin/MYC axis in CRC, which indicates that REG1α could function as a novel biomarker and a potential therapeutic target for patients with CRC.

Differential Effects of Sevoflurane Exposure on Long-Term Fear Memory in Neonatal and Adult Rats.

It remains unclear whether exposure to sevoflurane produces different effects on long-term cognitive function in developing and mature brains. In the present study, Sprague-Dawley neonatal rats at postnatal day (PND) 7 and adult rats (PND 56) were used in all experiments. We performed fear conditioning testing to examine long-term fear memory following 4-h sevoflurane exposure. We assessed hippocampal synapse ultrastructure with a transmission electron microscope. Moreover, we investigated the effect of sevoflurane exposure on the expression of postsynaptic protein 95 (PSD-95) and its binding protein kalirin-7 in the hippocampus. We observed that early exposure to sevoflurane in neonatal rats impairs hippocampus-dependent fear memory, reduces hippocampal synapse density, and dramatically decreases the expressions of PSD-95 and kalirin-7 in the hippocampus of the developing brain. However, sevoflurane exposure in adult rats has no effects on hippocampus-dependent fear memory and hippocampal synapse density, and the expressions of PSD-95 and kalirin-7 in the adult hippocampus are not significantly altered following sevoflurane treatment. Our results indicate that sevoflurane exposure produces differential effects on long-term fear memory in neonatal and adult rats and that PSD-95 signaling may be involved in the molecular mechanism for early sevoflurane exposure-caused long-term fear memory impairment.

Current advances and future perspectives on the functional roles and clinical implications of circular RNAs in esophageal squamous cell carcinoma: more influential than expected.

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive gastrointestinal cancers with high incidence and mortality. Therefore, it is necessary to identify novel sensitive and specific biomarkers for ESCC detection and treatment. Circular RNAs (circRNAs) are a type of noncoding RNAs featured by their covalently closed circular structure. This special structure makes circRNAs more stable in mammalian cells, coupled with their great abundance and tissue specificity, suggesting circRNAs may present enormous potential to be explored as valuable prognostic and diagnostic biomarkers for tumor. Mounting studies verified the critical roles of circRNAs in regulating ESCC cells malignant behaviors. Here, we summarized the current progresses in a handful of aberrantly expressed circRNAs, and elucidated their biological function and clinical significance in ESCC, and introduced a series of databases for circRNA research. With the improved advancement in high-throughput sequencing and bioinformatics technique, new frontiers of circRNAs will pave the path for the development of precision treatment in ESCC.

EGFR exon 20 insertion mutations in advanced non-small-cell lung cancer: current status and perspectives.

Platinum-based chemotherapy was previously the first-choice treatment for lung cancer. The discovery of epidermal growth factor receptor (EGFR) gene mutations and the development of EGFR tyrosine kinase inhibitors (TKIs) marked the beginning of the targeted therapy era for non-small-cell lung cancer (NSCLC). Thirty percent of NSCLC patients carry EGFR gene mutations. For these advanced NSCLC patients, EGFR-TKIs are currently preferred for their superior activity and survival benefits over platinum-based chemotherapy. However, therapeutic efficacy is quite different in patients with EGFR exon 20 insertion (ex20ins) mutations versus common mutations. Patients with ex20ins mutations are insensitive to EGFR-TKIs and have poor prognosis. Some drugs targeting EGFR ex20ins mutations have been approved. Here, we systematically reviewed the recent clinical research of and treatments used for EGFR ex20ins mutations, summarized the latest data on emerging therapies, and discussed future prospects and treatments.

IGF2BP2-induced circRUNX1 facilitates the growth and metastasis of esophageal squamous cell carcinoma through miR-449b-5p/FOXP3 axis.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is one of the most common digestive malignancies with relatively high morbidity and mortality. Emerging evidence suggests circular RNAs (circRNAs) play critical roles in tumor cell malignancy. However, the biological function and clinical significance of many circRNAs in ESCC remain elusive. METHODS: The expression level and clinical implication of circRUNX1 in ESCC tissues were evaluated using qRT-PCR. In vitro and in vivo functional studies were conducted to investigate the underlying biological effects of circRUNX1 on ESCC cell growth and metastasis. Moreover, bioinformatics analysis, RNA sequencing (RNA-seq), RNA immunoprecipitation (RIP) assays, dual-luciferase reporter assays, and rescue experiments were performed to explore the relationships between circRUNX1, miR-449b-5p, Forkhead box protein P3 (FOXP3), and insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2). RESULTS: CircRUNX1 was found to be significantly up-regulated in ESCC tissues and associated with TNM stage and differentiation grade. Functionally, circRUNX1 promoted ESCC cell proliferation and metastasis in vitro and in vivo. CircRUNX1 enhanced FOXP3 expression by competitively sponging miR-449b-5p. Notably, both miR-449b-5p mimics and FOXP3 knockdown restored the effects of circRUNX1 overexpression on cell proliferation and metastasis. Furthermore, IGF2BP2 binding to circRUNX1 prevented its degradation. CONCLUSIONS: IGF2BP2 mediated circRUNX1 functions as an oncogenic factor to facilitate ESCC progression through the miR-449b-5p/FOXP3 axis, implying that circRUNX1 has the potential to be a promising diagnostic marker and therapeutic target for ESCC patients.

Local ablation of pulmonary malignancies abutting pleura: Evaluation of midterm local efficacy and safety.

Objective: To retrospectively evaluate the efficacy and safety of local ablation treatment for adjacent pleural lung tumors. Materials and methods: Sixty-two patients who underwent pulmonary nodule ablation at the Affiliated Cancer Hospital of Zhengzhou University were enrolled between January 2016 and December 2020. All patients were followed up with enhanced computed tomography or magnetic resonance imaging within 48 h after treatment and 2, 4, 6, 9, and 12 months after treatment. All patients were followed for at least 12 months. Results: A total of 84 targeted tumors (62 patients) underwent 94 ablations. In the 12-month follow-up images, 69 of the 84 targeted tumors were completely ablated, 15 had incomplete ablation, and the 12-month incomplete ablation rate was 17.8% (15/84). Of the 15 incompletely ablated tumors, six had partial responses, five had stable disease, and four had progressive disease. The most common adverse event was pneumothorax, with an incidence of 54.8% (34/62). The second most common complication was pleural effusion, with an incidence rate of 41.9% (26/62). The incidence of needle-tract bleeding was 21% (13/62) and all patients were cured using hemostatic drugs. Serious complications were bronchopleural fistula in four patients (6.5%, 4/62) and needle tract metastasis in one patient. Four cases of bronchopleural fistula were found in the early stages and were cured after symptomatic treatment. Conclusion: Local ablation is effective for the treatment of adjacent pleural lung tumors, and its operation is safe and controllable.

A high interferon gamma signature of CD8+ T cells predicts response to neoadjuvant immunotherapy plus chemotherapy in gastric cancer.

Background: While the tumor microenvironment (TME) affects immune checkpoint blockade (ICB) efficacy, ICB also reshapes the characteristics of TME. Thus far, studies have focused on the TME evolution during neoadjuvant or adjuvant ICB therapy in gastric cancer (GC). However, the interaction between TME characteristics and neoadjuvant immunotherapy plus chemotherapy remains to be elucidated. Methods: We performed single-cell RNA sequencing on ten GC specimens pre- and post-neoadjuvant camrelizumab plus mFOLFOX6 to determine the impact of the TME on the efficacy of the combination therapy and the remodeling of TME by the therapy. Results: A high baseline interferon gamma (IFN-γ) signature in CD8+ T cells predicts better responses to the combination therapy. We also observed that the IFN-γ signature significantly decreased in multiple cell types, and the exhausted signature of CD8+ T cells was significantly suppressed during the neoadjuvant therapy. Conclusions: Our data reveal interactions between the TME and neoadjuvant immunotherapy plus chemotherapy in GC. Importantly, it also highlights the signature of CD8+ T cells in predicting response to the combination therapy in GC.

Case report: TP53 and RB1 loss may facilitate the transformation from lung adenocarcinoma to small cell lung cancer by expressing neuroendocrine markers.

Introduction: Transformation from lung adenocarcinoma (LUAD) to small cell lung cancer (SCLC) is one of the mechanisms responsible for acquired EGFR-TKIs resistance. Although it rarely happens this event determines a rapid disease deterioration and needs specific treatment. Patient and method: We report a case of 75-year-old LUAD female with a p.L858R mutation in Epidermal Growth Factor Receptor (EGFR) who presented with SCLC transformation after responding to first line osimertinib treatment for only 6 months. To understand the underlying molecular mechanism, we retrospectively sequenced the first (LUAD) and the second (SCLC) biopsy using a 56 multi-gene panel. Immunohistochemistry (IHC) staining and Fluorescence In Situ Hybridization (FISH) was applied to confirm the genetic aberrations identified. Results: EGFR p.E709A and p.L858R, Tumor Protein p53 (TP53) p.A159D and Retinoblastoma 1 (RB1) c.365-1G>A were detected in both the diagnostic LUAD and transformed SCLC samples. A high copy number gain for Proto-Oncogene C-Myc (MYC) and a Phosphoinositide 3-Kinase Alpha (PIK3CA) p.E545K mutation were found in the transformed sample specifically. Strong TP53 staining and negative RB1 staining were observed in both LUAD and SCLC samples, but FISH only identified MYC amplification in SCLC tissue. Conclusion: We consider the combined presence of MYC amplification with mutations in TP53 and RB1 as drivers of SCLC transformation. Our results highlight the need to systematically evaluate TP53 and RB1 status in LUAD patients to offer a different therapeutic strategy.

Personalized Treatment of Advanced Gastric Cancer Guided by the MiniPDX Model.

BACKGROUND: The morbidity and mortality of gastric cancer are high in China. There are challenges to develop precise and individualized drug regimens for patients with gastric cancer after a standard treatment. Choosing the most appropriate anticancer drug after a patient developing drug resistance is very important to improve the patient's prognosis. MiniPDX has been widely used as a new and reliable preclinical research model to predict the sensitivity of anticancer drugs. METHODS: The OncoVee® MiniPDX system developed by Shanghai LIDE Biotech Co., Ltd. was used to establish the MiniPDX models using specimens of patients with gastric cancer. The cancer tissues were biopsied under endoscopy, and then, the tumor cell suspension was prepared for a drug sensitivity test by subcutaneously implanting into Balb/c-nude mice. The selected optimal regimen obtained from the MiniPDX assay was used to treat patients with drug-resistant gastric cancer. RESULTS: We successfully established an individualized and sensitive drug screening system for four patients from January 2021 to July 2021. MiniPDX models identified potentially effective drugs for these four patients, with partial remission in two of the patients after treatment and disease progression in the remaining of two patients. Severe side effects from chemotherapy or targeted therapy were not observed in all patients. CONCLUSION: Establishing a personalized drug screening system for patients with drug-resistant gastric cancer can guide the selection of clinical drugs, improve the clinical benefit of patients, and avoid ineffective treatments. It can be an effective supplement for treatment options.

Combination of Low-Dose Gemcitabine and PD-1 Inhibitors for Treatment in Patients With Advanced Malignancies.

Purpose: This study determined the efficacy of low-dose gemcitabine combined with programmed death-1 (PD-1) inhibitors for treating multiple malignancies, providing a cost-effective and safe treatment option. Study Design: This study included 61 patients with advanced solid tumors treated with low-dose gemcitabine combined with PD-1 inhibitors at the Henan Cancer Hospital between January 2018 and February 2022. We retrospectively reviewed medical records to evaluate several clinical factors, including progression-free survival (PFS), overall survival (OS), adverse effects (AEs), and objective response to treatment. Results: Sixty-one patients received treatment with low-dose gemcitabine combined with PD-1 inhibitors. The objective response rate (ORR) was 29.5% and the disease control rate (DCR) was 62.3%. The median PFS was 4.3 months (95% confidence interval, 2.3 to 6.3 months) and the median OS was 15.0 months (95% confidence interval, 8.8 to 21.2 months). Hematological toxicity, mainly leukopenia or thrombocytopenia, was the most common AE, with any-grade and grade 3/4 hematological toxicity reported in 60.7 and 13.1% of patients, respectively. Conclusions: Low-dose gemcitabine combined with PD-1 inhibitors may offer a novel treatment option for patients with advanced malignancies.