Establishment and characterization of a novel multidrug-resistant pancreatic ductal adenocarcinoma cell line, PDAC-X1.

Drug resistance remains a significant challenge in the treatment of pancreatic cancer. The development of drug-resistant cell lines is crucial to understanding the underlying mechanisms of resistance and developing novel drugs to improve clinical outcomes. Here, a novel pancreatic cancer cell line, PDAC-X1, derived from Chinese patients has been established. PDAC-X1 was characterized by the immune phenotype, biology, genetics, molecular characteristics, and tumorigenicity. In vitro analysis revealed that PDAC-X1 cells exhibited epithelial morphology and cell markers (CK7 and CK19), expressed cancer-associated markers (E-cadherin, Vimentin, Ki-67, CEA, CA19-9), and produced pancreatic cancer-like organs in suspension culture. In vivo analysis showed that PDAC-X1 cells maintained tumorigenicity with a 100% tumor formation rate. This cell line exhibited a complex karyotype, dominated by subtriploid karyotypes. In addition, PDAC-X1 cells exhibited intrinsic multidrug resistance to multiple drugs, including gemcitabine, paclitaxel, 5-fluorouracil, and oxaliplatin. In conclusion, the PDAC-X1 cell line has been established and characterized, representing a useful and valuable preclinical model to study the underlying mechanisms of drug resistance and develop novel drug therapeutics to improve patient outcomes.

Netrin-1 Is an Important Mediator in Microglia Migration.

Microglia migrate to the cerebral cortex during early embryonic stages. However, the precise mechanisms underlying microglia migration remain incompletely understood. As an extracellular matrix protein, Netrin-1 is involved in modulating the motility of diverse cells. In this paper, we found that Netrin-1 promoted microglial BV2 cell migration in vitro. Mechanism studies indicated that the activation of GSK3ß activity contributed to Netrin-1-mediated microglia migration. Furthermore, Integrin α6/ß1 might be the relevant receptor. Single-cell data analysis revealed the higher expression of Integrin α6 subunit and ß1 subunit in microglia in comparison with classical receptors, including Dcc, Neo1, Unc5a, Unc5b, Unc5c, Unc5d, and Dscam. Microscale thermophoresis (MST) measurement confirmed the high binding affinity between Integrin α6/ß1 and Netrin-1. Importantly, activation of Integrin α6/ß1 with IKVAV peptides mirrored the microglia migration and GSK3 activation induced by Netrin-1. Finally, conditional knockout (CKO) of Netrin-1 in radial glial cells and their progeny led to a reduction in microglia population in the cerebral cortex at early developmental stages. Together, our findings highlight the role of Netrin-1 in microglia migration and underscore its therapeutic potential in microglia-related brain diseases.

Establishment and characterization of the PDAC-X3 cell line: a novel Chinese-origin pancreatic ductal adenocarcinoma cell line.

In this study, a novel pancreatic cancer cell line, termed pancreatic ductal adenocarcinoma (PDAC)-X3 cell line, was successfully derived from the primary tumor. Comprehensive analyses of its malignant phenotype, molecular properties, specific biomarkers, and histological features confirmed that PDAC-X3 cells serve as a valuable model for investigating the underlying mechanisms driving pancreatic carcinogenesis and advancing potential therapeutic strategies. The newly established cell line was continuously cultured for over 12 months and was stably passaged through more than 50 generations. Morphologically, PDAC-X3 cells displayed characteristics typical of epithelial tumors. The population doubling time for PDAC-X3 cells was determined to be 50 h. Karyotype analysis revealed that 75% of PDAC-X3 cells presented as hypotriploid, while 25% were sub-tetraploid, with representative karyotypes being 53 and XY der (1) inv (9) der (22). In suspension culture, PDAC-X3 cells efficiently formed organoids. Upon inoculation into BALB/C nude mice, these cells initiated the development of xenograft tumors, achieving a tumor formation rate of 33%. Morphologically, these xenografted tumors closely resembled the primary tumor. Drug sensitivity assays indicated that PDAC-X3 cells exhibited resistance to oxaliplatin but demonstrated sensitivity to 5-Fluorouracil (5-FU), gemcitabine, and paclitaxel. Immunohistochemical analysis revealed that CK7, CK19, E-cadherin, Vimentin, CA19-9 were positively expressed in PDAC-X3 cells. Meanwhile, the expression rate for Ki-67 was 30%, and that for CEA was not detected. Our findings underscore that PDAC-X3 represents a novel pancreatic cancer cell line, positioning it as a valuable model for basic research and the advancement of therapeutic strategies against pancreatic cancer.

New phenols and one aminobenzoic acid derivative isolated from the roots of Rhus chinensis Mill.

Four new phenols and one new aminobenzoic acid derivative, with five known phenols were isolated from the roots of Rhus chinensis Mill. Their structures were elucidated by UV, IR, HRESIMS, 1D and 2D NMR spectra, as well as optical rotations. Compound 4 significantly inhibited mouse ear inflammation (inhibitory rate of 44.03%), and significantly extended the time of pain response (extension rate of 48.55%), showing significant anti-inflammatory and analgesic effects in vivo.

Paired conditional generative adversarial network for highly accelerated liver 4D MRI.

Purpose.4D MRI with high spatiotemporal resolution is desired for image-guided liver radiotherapy. Acquiring densely sampling k-space data is time-consuming. Accelerated acquisition with sparse samples is desirable but often causes degraded image quality or long reconstruction time. We propose the Reconstruct Paired Conditional Generative Adversarial Network (Re-Con-GAN) to shorten the 4D MRI reconstruction time while maintaining the reconstruction quality.Methods.Patients who underwent free-breathing liver 4D MRI were included in the study. Fully- and retrospectively under-sampled data at 3, 6 and 10 times (3×, 6× and 10×) were first reconstructed using the nuFFT algorithm. Re-Con-GAN then trained input and output in pairs. Three types of networks, ResNet9, UNet and reconstruction swin transformer (RST), were explored as generators. PatchGAN was selected as the discriminator. Re-Con-GAN processed the data (3D +t) as temporal slices (2D +t). A total of 48 patients with 12 332 temporal slices were split into training (37 patients with 10 721 slices) and test (11 patients with 1611 slices). Compressed sensing (CS) reconstruction with spatiotemporal sparsity constraint was used as a benchmark. Reconstructed image quality was further evaluated with a liver gross tumor volume (GTV) localization task using Mask-RCNN trained from a separate 3D static liver MRI dataset (70 patients; 103 GTV contours).Results.Re-Con-GAN consistently achieved comparable/better PSNR, SSIM, and RMSE scores compared to CS/UNet models. The inference time of Re-Con-GAN, UNet and CS are 0.15, 0.16, and 120 s. The GTV detection task showed that Re-Con-GAN and CS, compared to UNet, better improved the dice score (3× Re-Con-GAN 80.98%; 3× CS 80.74%; 3× UNet 79.88%) of unprocessed under-sampled images (3× 69.61%).Conclusion.A generative network with adversarial training is proposed with promising and efficient reconstruction results demonstrated on an in-house dataset. The rapid and qualitative reconstruction of 4D liver MR has the potential to facilitate online adaptive MR-guided radiotherapy for liver cancer.

Evaluating drug interaction potential from cytokine release syndrome using a physiologically based pharmacokinetic model: A case study of teclistamab.

Cytokine release syndrome (CRS) was associated with teclistamab treatment in the phase I/II MajesTEC-1 study. Cytokines, especially interleukin (IL)-6, are known suppressors of cytochrome P450 (CYP) enzymes' activity. A physiologically based pharmacokinetic model evaluated the impact of IL-6 serum levels on exposure of substrates of various CYP enzymes (1A2, 2C9, 2C19, 3A4, 3A5). Two IL-6 kinetics profiles were assessed, the mean IL-6 profile with a maximum concentration (Cmax) of IL-6 (21 pg/mL) and the IL-6 profile of the patient presenting the highest IL-6 Cmax (288 pg/mL) among patients receiving the recommended phase II dose of teclistamab in MajesTEC-1. For the mean IL-6 kinetics profile, teclistamab was predicted to result in a limited change in exposure of CYP substrates (area under the curve [AUC] mean ratio 0.87-1.20). For the maximum IL-6 kinetics profile, the impact on omeprazole, simvastatin, midazolam, and cyclosporine exposure was weak to moderate (mean AUC ratios 1.90-2.23), and minimal for caffeine and s-warfarin (mean AUC ratios 0.82-1.25). Maximum change in exposure for these substrates occurred 3-4 days after step-up dosing in cycle 1. These results suggest that after cycle 1, drug interaction from IL-6 effect has no meaningful impact on CYP activities, with minimal or moderate impact on CYP substrates. The highest risk of drug interaction is expected to occur during step-up dosing up to 7 days after the first treatment dose (1.5 mg/kg subcutaneously) and during and after CRS.

Cell division cyclin 25C knockdown inhibits hepatocellular carcinoma development by inducing endoplasmic reticulum stress.

BACKGROUND: Cell division cyclin 25C (CDC25C) is a protein that plays a critical role in the cell cycle, specifically in the transition from the G2 phase to the M phase. Recent research has shown that CDC25C could be a potential therapeutic target for cancers, particularly for hepatocellular carcinoma (HCC). However, the specific regulatory mechanisms underlying the role of CDC25C in HCC tumorigenesis and development remain incompletely understood. AIM: To explore the impact of CDC25C on cell proliferation and apoptosis, as well as its regulatory mechanisms in HCC development. METHODS: Hepa1-6 and B16 cells were transduced with a lentiviral vector containing shRNA interference sequences (LV-CDC25C shRNA) to knock down CDC25C. Subsequently, a xenograft mouse model was established by subcutaneously injecting transduced Hepa1-6 cells into C57BL/6 mice to assess the effects of CDC25C knockdown on HCC development in vivo. Cell proliferation and migration were evaluated using a Cell Counting Kit-8 cell proliferation assays and wound healing assays, respectively. The expression of endoplasmic reticulum (ER) stress-related molecules (glucose-regulated protein 78, X-box binding protein-1, and C/EBP homologous protein) was measured in both cells and subcutaneous xenografts using quantitative real-time PCR (qRT-PCR) and western blotting. Additionally, apoptosis was investigated using flow cytometry, qRT-PCR, and western blotting. RESULTS: CDC25C was stably suppressed in Hepa1-6 and B16 cells through LV-CDC25C shRNA transduction. A xenograft model with CDC25C knockdown was successfully established and that downregulation of CDC25C expression significantly inhibited HCC growth in mice. CDC25C knockdown not only inhibited cell proliferation and migration but also significantly increased the ER stress response, ultimately promoting ER stress-induced apoptosis in HCC cells. CONCLUSION: The regulatory mechanism of CDC25C in HCC development may involve the activation of ER stress and the ER stress-induced apoptosis signaling pathway.

Serum ß-klotho is a potential biomarker for the progression of hepatitis B virus-related liver diseases.

INTRODUCTION: Hepatitis B virus (HBV) infection is a global epidemic that can lead to several liver diseases, seriously affecting people's health. This study aimed to investigate the clinical potential of serum ß-klotho (KLB) as a promising biomarker in HBV-related liver diseases. METHODOLOGY: This study enrolled 30 patients with chronic hepatitis B (CHB), 35 with HBV-related cirrhosis, 66 with HBV-related hepatocellular carcinoma (HCC), and 48 healthy individuals. ELISA measured the levels of serum KLB in the four groups. We then compared the differences in serum KLB levels among the groups and analyzed the relationship between serum KLB and routine clinical parameters. RESULTS: The concentrations of serum KLB levels were increased sequentially among the healthy subjects, the HBV-related CHB group, the HBV-related cirrhosis group, and the HBV-related HCC group (p < 0.05). Expression of KLB was positively correlated with alpha-fetoprotein (AFP), total bilirubin, direct bilirubin, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl-transferase, alkaline phosphatase, total bile acid, serum markers for liver fibrosis, ascites, cirrhosis, splenomegaly, and model for end-stage liver disease sodium, while negatively correlated with platelet count, albumin, and prothrombin activity (p < 0.05). In addition, serum KLB has better sensitivity in diagnosing HCC than AFP, and serum KLB combined with AFP has higher sensitivity and specificity than AFP alone in diagnosing HCC. CONCLUSIONS: Serum KLB level is associated with the severity of HBV-related liver diseases and has important diagnostic value for HCC. Therefore, it could be a predictive biomarker for monitoring disease progression.

Potential decoupling of CO2 and Hg uptake process by global vegetation in the 21st century.

Mercury (Hg), a potent neurotoxin posing risks to human health, is cycled through vegetation uptake, which is susceptible to climate change impacts. However, the extent and pattern of these impacts are largely unknown, obstructing predictions of Hg's fate in terrestrial ecosystems. Here, we evaluate the effects of climate change on vegetation elemental Hg [Hg(0)] uptake using a state-of-the-art global terrestrial Hg model (CLM5-Hg) that incorporates plant physiology. In a business-as-usual scenario, the terrestrial Hg(0) sink is predicted to decrease by 1870 Mg yr-1 in 2100, that is ~60% lower than the present-day condition. We find a potential decoupling between the trends of CO2 assimilation and Hg(0) uptake process by vegetation in the 21st century, caused by the decreased stomatal conductance with increasing CO2. This implies a substantial influx of Hg into aquatic ecosystems, posing an elevated threat that warrants consideration during the evaluation of the effectiveness of the Minamata Convention.

Quantifying gadolinium-based nanoparticle uptake distributions in brain metastases via magnetic resonance imaging.

AGuIX, a novel gadolinium-based nanoparticle, has been deployed in a pioneering double-blinded Phase II clinical trial aiming to assess its efficacy in enhancing radiotherapy for tumor treatment. This paper moves towards this goal by analyzing AGuIX uptake patterns in 23 patients. A phantom was designed to establish the relationship between AGuIX concentration and longitudinal ( T 1 ) relaxation. A 3T MRI and MP2RAGE sequence were used to generate patient T 1 maps. AGuIX uptake in tumors was determined based on longitudinal relaxivity. AGuIX (or placebo) was administered to 23 patients intravenously at 100 mg/kg 1-5 hours pre-imaging. Each of 129 brain metastases across 23 patients were captured in T 1 maps and examined for AGuIX uptake and distribution. Inferred AGuIX recipients had average tumor uptakes between 0.012 and 0.17 mg/ml, with a mean of 0.055 mg/ml. Suspected placebo recipients appeared to have no appreciable uptake. Tumors presented with varying spatial AGuIX uptake distributions, suspected to be related to differences in accumulation time and patient-specific bioaccumulation factors. This research demonstrates AGuIX's ability to accumulate in brain metastases, with quantifiable uptake via T 1 mapping. Future analyses will extend these methods to complete clinical trial data (~ 134 patients) to evaluate the potential relationship between nanoparticle uptake and possible tumor response following radiotherapy.Clinical Trial Registration Number: NCT04899908.Clinical Trial Registration Date: 25/05/2021.

A novel multidrug-resistant cell line from a Chinese patient with pancreatic ductal adenocarcinoma.

Chemotherapy resistance poses clinical challenges in pancreatic cancer treatment. Developing cell lines resistant to chemotherapy is crucial for investigating drug resistance mechanisms and identifying alternative treatment pathways. The genetic and biological attributes of pancreatic cancer depend on its aetiology, racial demographics and anatomical origin, underscoring the need for models that comprehensively represent these characteristics. Here, we introduce PDAC-X2, a pancreatic cancer cell line derived from Chinese patients. We conducted a comprehensive analysis encompassing the immune phenotype, biology, genetics, molecular characteristics and tumorigenicity of the cell line. PDAC-X2 cells displayed epithelial morphology and expressed cell markers (CK7 and CK19) alongside other markers (E-cadherin, Vimentin, Ki-67, CEA and CA19-9). The population doubling time averaged around 69 h. In vivo, PDAC-X2 cells consistently maintained their tumorigenicity, achieving a 100% tumour formation rate. Characterised by a predominantly tetraploid karyotype, this cell line exhibited a complex genetic markup. Notably, PDAC-X2 cells demonstrated resistance to multiple drugs, including gemcitabine, paclitaxel, 5-fluorouracil and oxaliplatin. In conclusion, PDAC-X2 presents an invaluable preclinical model. Its utility lies in facilitating the study of drug resistance mechanisms and the exploration of alternative therapeutic approaches aimed at enhancing the prognosis of this tumour type.

Semaphorin3C identified as mediator of neuroinflammation and microglia polarization after spinal cord injury.

Excessive neuroinflammation after spinal cord injury (SCI) is a major hurdle during nerve repair. Although proinflammatory macrophage/microglia-mediated neuroinflammation plays important roles, the underlying mechanism that triggers neuroinflammation and aggravating factors remain unclear. The present study identified a proinflammatory role of semaphorin3C (SEMA3C) in immunoregulation after SCI. SEMA3C expression level peaked 7 days post-injury (dpi) and decreased by 14 dpi. In vivo and in vitro studies revealed that macrophages/microglia expressed SEMA3C in the local microenvironment, which induced neuroinflammation and conversion of proinflammatory macrophage/microglia. Mechanistic experiments revealed that RAGE/NF-κB was downstream target of SEMA3C. Inhibiting SEMA3C-mediated RAGE signaling considerably suppressed proinflammatory cytokine production, reversed polarization of macrophages/microglia shortly after SCI. In addition, inhibition of SEMA3C-mediated RAGE signaling suggested that the SEMA3C/RAGE axis is a feasible target to preserve axons from neuroinflammation. Taken together, our study provides the first experimental evidence of an immunoregulatory role for SEMA3C in SCI via an autocrine mechanism.

Systems pharmacodynamic model of combined gemcitabine and trabectedin in pancreatic cancer cells. Part I.Çô Effects on signal transduction pathways related to tumor growth.

Pancreatic ductal adenocarcinoma (PDAC) is often chemotherapy-resistant, and novel drug combinations would fill an unmet clinical need. Previously we reported synergistic cytotoxic effects of gemcitabine and trabectedin on pancreatic cancer cells, but underlying protein-level interaction mechanisms remained unclear. We employed a reliable, sensitive, comprehensive, quantitative, high-throughput IonStar proteomic workflow to investigate the time course of gemcitabine and trabectedin effects, alone and combined, upon pancreatic cancer cells. MiaPaCa-2 cells were incubated with vehicle (controls), gemcitabine, trabectedin, and their combinations over 72 hours. Samples were collected at intervals and analyzed using the label-free IonStar liquid chromatography-mass spectrometry (LC-MS/MS) workflow to provide temporal quantification of protein expression for 4,829 proteins in four experimental groups. To characterize diverse signal transduction pathways, a comprehensive systems pharmacodynamic (SPD) model was developed. The analysis is presented in two parts. Here, Part I describes drug responses in cancer cell growth and migration pathways included in the full model: receptor tyrosine kinase- (RTK), integrin-, G-protein coupled receptor- (GPCR), and calcium-signaling pathways. The developed model revealed multiple underlying mechanisms of drug actions, provides insight into the basis of drug interaction synergism, and offers a scientific rationale for potential drug combination strategies.

Investigating the clinical role and prognostic value of genes related to insulin-like growth factor signaling pathway in thyroid cancer.

BACKGROUND: Thyroid cancer (THCA) is the most common endocrine malignancy having a female predominance. The insulin-like growth factor (IGF) pathway contributed to the unregulated cell proliferation in multiple malignancies. We aimed to explore the IGF-related signature for THCA prognosis. METHOD: The TCGA-THCA dataset was collected from the Cancer Genome Atlas (TCGA) for screening of key prognostic genes. The limma R package was applied for differentially expressed genes (DEGs) and the clusterProfiler R package was used for the Gene Ontology (GO) and KEGG analysis of DEGs. Then, the un/multivariate and least absolute shrinkage and selection operator (Lasso) Cox regression analysis was used for the establishment of RiskScore model. Receiver Operating Characteristic (ROC) analysis was used to verify the model's predictive performance. CIBERSORT and MCP-counter algorithms were applied for immune infiltration analysis. Finally, we analyzed the mutation features and the correlation between the RiskScore and cancer hallmark pathway by using the GSEA. RESULT: We obtained 5 key RiskScore model genes for patient's risk stratification from the 721 DEGs. ROC analysis indicated that our model is an ideal classifier, the high-risk patients are associated with the poor prognosis, immune infiltration, high tumor mutation burden (TMB), stronger cancer stemness and stronger correlation with the typical cancer-activation pathways. A nomogram combined with multiple clinical features was developed and exhibited excellent performance upon long-term survival quantitative prediction. CONCLUSIONS: We constructed an excellent prognostic model RiskScore based on IGF-related signature and concluded that the IGF signal pathway may become a reliable prognostic phenotype in THCA intervention.

AAV-mediated VEGFA overexpression promotes angiogenesis and recovery of locomotor function following spinal cord injury via PI3K/Akt signaling.

Spinal cord injury (SCI) is a disorder of the central nervous system resulting from various factors such as trauma, inflammation, tumors, and other etiologies. This condition leads to impairment in motor, sensory, and autonomic functions below the level of injury. Limitations of current therapeutic approaches prompt an investigation into therapeutic angiogenesis through persistent local expression of proangiogenic factors. Here, we investigated whether overexpression of adeno-associated virus (AAV)-mediated vascular endothelial growth factor A (VEGFA) in mouse SCI promoted locomotor function recovery, and whether the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway was mechanistically involved. Three weeks before SCI, AAV-VEGFA was injected at the T10 level to induce VEGFA overexpression. Neurofunctional, histological, and biochemical assessments were done to determine tissue damage and/or recovery of neuromuscular and behavioral impairments. Daily injections of the PI3K/Akt pathway inhibitor LY294002 were made to assess a possible mechanism. AAV-VEGFA overexpression dramatically improved locomotor function and ameliorated pathological injury caused by SCI. Improved motor-evoked potentials in hindlimbs and more spinal CD31-positive microvessels were observed in AAV-VEGFA-overexpressing mice. LY294002 reduced PI3K and Akt phosphorylation levels and attenuated AAV-VEGFA-related improvements. In conclusion, sustained local AAV-mediated VEGFA overexpression in spinal cord can significantly promote angiogenesis and ameliorate locomotor impairment after SCI in a contusion mouse model through activation of the PI3K/Akt signaling pathway.

Mechanism of Acupuncture in Treating Obesity: Advances and Prospects.

Obesity is a common metabolic syndrome that causes a significant burden on individuals and society. Conventional therapies include lifestyle interventions, bariatric surgery, and pharmacological therapies, which are not effective and have a high risk of adverse events. Acupuncture is an effective alternative for obesity, it modulates the hypothalamus, sympathetic activity and parasympathetic activity, obesity-related hormones (leptin, ghrelin, insulin, and CCK), the brain-gut axis, inflammatory status, adipose tissue browning, muscle blood flow, hypoxia, and reactive oxygen species (ROS) to influence metabolism, eating behavior, motivation, cognition, and the reward system. However, hypothalamic regulation by acupuncture should be further demonstrated in human studies using novel techniques, such as functional MRI (fMRI), positron emission tomography (PET), electroencephalogram (EEG), and magnetoencephalography (MEG). Moreover, a longer follow-up phase of clinical trials is required to detect the long-term effects of acupuncture. Also, future studies should investigate the optimal acupuncture therapeutic option for obesity. This review aims to consolidate the recent improvements in the mechanism of acupuncture for obesity as well as discuss the future research prospects and potential of acupuncture for obesity.

Establishment and characterization of DPC-X4: a novel mixed-type ampullary cancer cell line.

Mixed-type ampullary cancer is a distinct subtype of ampullary cancer that manifests a merging of the biological characteristics of both intestinal and pancreaticobiliary subtypes. The absence of established cell lines specific to this subtype has resulted in a concomitant scarcity of research on its tumorigenic mechanisms and the development of novel therapeutic modalities. The present study achieved the successful establishment of a novel mixed-type ampullary cancer cell line, designated DPC-X4 through primary culture techniques. Subsequent analyses pertaining to phenotypic characteristics, molecular profiling, biomarker identification, and histological features validated the DPC-X4 cell line as a potent model for delineating the pathogenesis of mixed-type ampullary cancer and facilitating the development of new pharmacological agents. This newly established cell line was subjected to continuous cultivation for 1 year, with stable passaging for over 50 generations. Notably, the DPC-X4 cell line manifested typical morphological features associated with epithelial tumors. Furthermore, the population doubling time for the DPC-X4 cell line was determined at 70 h. Short tandem repeat (STR) analysis confirmed that the DPC-X4 cell line exhibited a high genetic concordance with the primary tumor from the patient. Karyotypic profiling indicated an abnormal sub-triploid karyotype, with representative karyotypes of 57, XXY inv (9), 14p + , 15p + , der (17), + mar. The DPC-X4 cell line demonstrated a high capacity for efficient organoid formation under suspension culture conditions. In addition, the subcutaneous inoculation of DPC-X4 cells into NXG mice led to the formation of xenografted tumors. The results of drug sensitivity testing indicated that DPC-X4 cells were sensitive to paclitaxel and resistant to oxaliplatin, 5-fluorouracil, and gemcitabine. Immunohistochemistry revealed positive expression of CK7, CK19, and CK20 in DPC-X4 cells, while CDX2 demonstrated negative expression. In addition, positive expression of E-cadherin and vimentin was identified in DPC-X4 cells, with a proliferation index indicated by Ki-67 at 70%. The findings of our study establish DPC-X4 as a novel mixed-type ampullary cancer cell line, which can serve as a potential experimental model for exploring the pathogenesis of ampullary cancer and the development of therapeutic drugs.

Establishment and Characterization of a New Intrahepatic Cholangiocarcinoma Cell Line, ICC-X2.

Background: Intrahepatic cholangiocarcinoma (ICC) is an aggressive malignant tumor of the biliary tract that is prone to recurrence and metastasis and is characterized by poor sensitivity to chemotherapy and overall prognosis. For these reasons, there is an urgent need to understand its pathological mechanisms and develop effective treatments. To address this challenge, the establishment of suitable preclinical models is critical. Methods: Fresh ICC tissue samples were used for primary culture and subculture. The cell line was evaluated by cell proliferation assays, clonal formation assays, karyotype analysis, and short tandem repeat (STR) analysis. Drug resistances against oxaliplatin, paclitaxel, gemcitabine and 5-fluorouracil (5-FU) were evaluated by CCK-8 assay. Subcutaneous injection of 1 × 106 cells to three BALB/c nude mice was conducted for xenograft studies. The hematoxylin and eosin (H&E) staining was used to detect the pathological status of the cell line. The expression of biomarkers CK7, CK19, Ki-67, E-cadherin and vimentin was determined by immunocytochemistry assay. Results: A new ICC cell line named ICC-X2 was successfully established. Like ICC-X3 established using the same patient's metastatic tumor, the cell line has been continuously cultured in vitro for more than a year and has been passaged more than 100 times. ICC-X2 retained the typical biliary epithelial morphology. The population doubling time of ICC-X2 is 48 h. The cells demonstrated an abnormal nearly tetraploid karyotype. The STR analysis confirmed that ICC-X2 was highly consistent with the primary tumor tissue and not cross-contaminated by existing cell lines. ICC-X2 cells positively expressed CK7, CK19, E-cadherin, and vimentin, and the positive expression of Ki-67 in ICC-X2 cells was 40%. The ICC-X2 cells exhibited a strong clonogenic ability. The drug sensitivity test indicated that ICC-X2 was sensitive to oxaliplatin and paclitaxel, but naturally resistant to gemcitabine and 5-FU. ICC-X2 was rapidly able to form transplanted tumors in vivo after subcutaneous inoculation in nude mice. Conclusions: ICC-X2 is an excellent experimental model that can be used for studying the occurrence, development, and metastasis of ICC and investigating the mechanism of tumor drug resistance.