Gastric Carcinoma Cells Research Articles

BS SO17 - Large Bowel Occlusion as a Manifestation of Gastric Adenocarcinoma in a Patient with Previous Gastric Bypass

Abstract Background Gastric bypass surgery has become one of the hallmarks of the treatment of obesity and metabolic syndrome. Over the last decade, an increasing number of gastric cancer cases have been reported following gastric bypass, particularly in the excluded stomach. The anatomical changes and the difficult access to the excluded stomach via endoscopy hinder the diagnosis and treatment of this cancer. Method Literature review and clinical case analysis through clinical records and exam results. Results A 59-year-old male with a history of gastric bypass 15 years prior was admitted to the emergency department with bowel occlusion. A CT scan revealed colonic obstruction due to invasion by a neoplastic/inflammatory process. Consequently, a right hemicolectomy was performed. Histopathological analysis revealed infiltration of the colonic wall by poorly cohesive gastric carcinoma cells. A follow-up CT scan confirmed a lesion in the excluded stomach. A LAMS (lumen-apposing metal stent) was placed to repermeabilize the excluded stomach, and biopsies confirmed gastric mixed adenocarcinoma. A gastroduodenal stent was placed for antropyloric stenosis. A multidisciplinary team opted for palliative chemotherapy. Conclusion The association between bariatric surgery and gastric cancer remains controversial. As described in previous studies, this clinical case demonstrates that gastric adenocarcinoma in patients who underwent gastric bypass often presents as an aggressive and advanced-stage disease. Given the mortality associated with gastric cancer and the increasing number of bariatric surgeries, this case report highlights the important need to develop patient selection protocols for gastric bypass and respective appropriate follow-up.

Anti-inflammatory effects of eupatilin on Helicobacter pylori CagA-induced gastric inflammation.

Eupatilin, a flavone isolated from Artemisia species, exerts anti-inflammatory, anti-oxidative, and anti-neoplastic activities. However, the effects of eupatilin on H. pylori-associated gastritis remain unclear. Thus, this study aimed to investigate the anti-inflammatory effects of eupatilin on gastric epithelial cells infected with cytotoxin-associated gene A (CagA)-positive Helicobacter pylori. AGS human gastric carcinoma cells were infected with a CagA-positive H. pylori strain and then treated with 10, 50, or 100 ng of eupatilin. After 24 h, the expression levels of CagA, phosphoinositide 3-kinase 1 (PI3K), nuclear factor (NF)-κB, interleukin (IL)-1β, and tumor necrosis factor (TNF)-α in the cell lysates were measured using western blotting, and the mRNA levels of IL-6, IL-8, and monocyte chemoattractant protein (MCP)-1 were measured using real-time polymerase chain reaction. CagA translocation into AGS cells resulted in an elongated cell morphology, which was significantly suppressed by eupatilin treatment in a dose-dependent manner. Immunofluorescence staining for anti-CagA showed that eupatilin treatment dose-dependently inhibited CagA expression in the H. pylori-infected AGS cells. H. pylori infection increased the levels of pro-inflammatory cytokines including IL-1β, TNF-α, IL-6, IL-8, and MCP-1, and eupatilin treatment significantly reduced the levels of these cytokines in a dose-dependent manner. Additionally, eupatilin treatment dose-dependently suppressed the expression of PI3K and NF-κB. Eupatilin treatment demonstrated anti-inflammatory effects on CagA-positive H. pylori-infected gastric epithelial cells by inhibiting CagA translocation, thereby suppressing the NF-κB signaling pathway. These results suggest that eupatilin plays a protective role against CagA-positive H. pylori-induced gastritis.

Curcumin derivative C210 induces Epstein–Barr virus lytic cycle and inhibits virion production by disrupting Hsp90 function

Lytic induction therapy was devised to selectively combat malignancies associated with Epstein–Barr virus (EBV) by triggering viral reactivation from latency. At present, the major challenges of lytic induction therapy are to maximize reactivating efficiencies and meanwhile minimize infectious virion production. C210, a novel curcumin derivative with potent Hsp90 inhibitory activity, was explored for EBV-reactivating and virion-producing effects in EBV-positive nasopharyngeal carcinoma (NPC) and gastric carcinoma (GC) cell lines. And the molecular mechanisms underlying these effects were determined. Follow C210 treatment, EBV lytic RNAs and proteins were upregulated, but infectious virions were not produced. Knockdown of heat shock protein 90 (Hsp90) induced expression of lytic RNAs and proteins, and diminished C210-driven EBV lytic induction. Pretreatment with an X box binding protein 1 (XBP1) inhibitor reduced C210-induced EBV lytic RNA. Furthermore, we demonstrated that C210 inhibited the binding of Hsp90 with its clients, signal transducer and activator of transcription 3 (STAT3) and xeroderma pigmentosum group B-complementing protein (XPB), which subsequently promoted their proteasomal degradation. Degradation of STAT3 by C210 enhanced the EBV-reactivating and anticancer capacity of suberoylanilide hydroxamic acid (SAHA). Depletion of XPB blocked SAHA-induced expression of late viral genes and production of infectious virions. These results elucidate a novel Hsp90 inhibitor targeting EBV lytic phase and extend the research on lytic induction strategy, which may offer reference value in the treatment of EBV-positive malignancies.

Deletion of glycosyltransferase galE impairs the InlB anchoring and pathogenicity of Listeria monocytogenes

ABSTRACT Listeria monocytogenes (L. monocytogenes) is a foodborne intracellular pathogen that causes serious disease in both humans and animals. InlB is the major internalin protein of L. monocytogenes, which anchors to the bacterial surface and mediates its invasion into various host cells. Recent studies have shown that galactosylation of the cell wall polymer wall teichoic acid (WTA) is essential for InlB anchoring on the cell surface of L. monocytogenes serotype 4b strains. Galactosylation of WTA is exerted by the coordinated action of several glycosyltransferases, including GalU, GalE, GtcA, GttA, and GttB. Among these glycosyltransferases, GttA and GttB are specific to serotype 4b strains, whereas GalE, GalU, and GtcA are conserved across all serotypes. The role of GalE in InlB anchoring and L. monocytogenes pathogenicity remains unclear. In this study, we deleted the galE gene, which is involved in galactosylation, from L. monocytogenes strain ScottA. We found that galE deletion reduced InlB anchoring, weakened bacterial adhesion and invasion of Caco-2 cells (human colorectal adenocarcinoma cells) and MGC803 cells (human gastric carcinoma cells), increased phagocytosis but decreased proliferation in RAW264.7 cells (mouse mononuclear macrophage leukaemia cells), and decreased bacteria load, mortality, and tissue damage in infected mice. Taken together, galE deletion significantly reduced the anchoring of InlB and weakened the pathogenicity of L. monocytogenes. This finding provides new insights into the correlation between cell wall modification and pathogenicity of L. monocytogenes.

Mechanistic study of Nidus Vespae inhibiting gastric cancer in vitro through the JAK2/STAT3 signaling pathway

Ethnopharmacological relevanceNidus Vespae, an animal-derived traditional Chinese medicine, has a long-standing history in treating inflammatory conditions and tumor-related diseases. Notably, Nidus Vespae decoction (NVD) has been shown to inhibit the proliferation of gastric cancer cells, although the underlying mechanisms remain unclear. ObjectiveThis study aimed to elucidate the efficacy and mechanisms by which NVD exerts its therapeutic effects on gastric cancer. Materials and methodsWe employed the Cell Counting Kit-8 (CCK-8) assay to assess the impact of NVD on gastric cancer cell proliferation, while flow cytometry was utilized to evaluate cell cycle arrest and apoptosis. Differentially expressed proteins (DEPs) were identified by proteomics analysis, which were further analyzed through Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. Protein-protein interaction (PPI) analysis was conducted to identify the hub genes. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were conducted to assess mRNA and protein levels related to apoptosis, cell cycle regulation, and the JAK2/STAT3 pathway. Rescue experiments with Colivelin TFA confirmed the role of NVD in inhibiting gastric cancer cell proliferation. UPLC-HRMS and HS-SPME-GC-MS technologies were performed to analyze the composition of NVD, and the bioinformatics tool called BATMAN-TCM database was used for functional analyses. ResultsOur results demonstrated that NVD significantly hindered the proliferation of gastric cancer cells, initiated programmed cell death, and induced cell cycle arrest in G2/M or G0/G1 phases in various gastric carcinoma cells in vitro. The identified DEPs were involved in several cancer-related pathways and signal transduction processes, notably the JAK-STAT receptor signaling pathway. NVD was found to down-regulate the JAK2/STAT3 signaling cascade, and reactivation of STAT3 diminished its anti-gastric cancer effects. Finally, the ingredient-target-disease network analysis also verified the anti-tumor effect of NVD. ConclusionThis study highlights the potential of Nidus Vespae as a therapeutic agent for gastric cancer, providing insights into its molecular mechanisms of action.

Synthesis of new pyridine based ONNO type schiff bases and Cd(II) complexes, investigation of structural, electronic and anti-cancer properties as computationally and experimentally

Pyridine based Schiff bases and their Cd(II) complexes were synthesized and characterized by spectral techniques which are ATR-IR, 1H NMR, 13C NMR, LC/QTOF-MS, and Single Crystal XRD. Structural properties and geometric parameters of these compounds were investigated both experimental and computational analyses. Electronic properties of Schiff bases were investigated by Hirshfeld surface analyses and molecular electrostatic potential (MEP) map calculations. All experimentally obtained data were supported by computational chemistry methods. B3LYP/6–31G(d) level was used for synthesized Schiff bases while B3LYP/6–31G(d)(LANL2DZ) level was used for Cd(II) complexes. Cell viability assays were performed to determine anticancer properties of related compounds against breast adenocarcinoma (MCF-7), colorectal adenocarcinoma (HT-29), and gastric carcinoma (SNU-16) cell lines. It was found that anticancer activity increased with complexation. The synthesized molecules were found to be more effective against HT-29. Furthermore, molecular docking calculations for each compounds were done against histone deacetylase 1 (HDAC1) due to the fact that expression level of HDAC1 is acceptable range.

Discovery of novel, orally bioavailable phenylacetamide derivatives as multikinase inhibitors and in vivo efficacy study in hepatocellular carcinoma animal models

Hepatocellular carcinoma (HCC) is considered as one of the leading causes of death in liver disease patients. Several signal transduction pathways are involved in HCC pathogenesis. Multikinase inhibitors (MKIs) show beneficial effects for HCC and the FDA approved a few MKIs including sorafenib, lenvatinib for HCC treatments. Here, a novel series of phenylacetamide derivatives were designed, synthesized and evaluated as multikinase inhibitors. Several compounds showed nanomolar IC50 values against FLT1, FLT3, FLT4, KDR, PDGFRα, PDGFRβ. The compounds were tested against human hepatocellular carcinoma (HCC), human colon adenocarcinoma and human gastric carcinoma cell lines. With favorable pharmacokinetics profiles, compound 12 and compound 14 were selected for in vivo efficacy studies in Hep3B mice models and demonstrated efficacious than sorafenib.

DCLK1 induces a pro-tumorigenic phenotype to drive gastric cancer progression.

Doublecortin-like kinase 1 (DCLK1) is a proposed driver of gastric cancer (GC) that phosphorylates serine and threonine residues. Here, we showed that the kinase activity of DCLK1 orchestrated cancer cell-intrinsic and-extrinsic processes that led to pro-invasive and pro-metastatic reprogramming of GC cells. Inhibition of the kinase activity of DCLK1 reduced the growth of subcutaneous xenograft tumors formed from MKN1 human gastric carcinoma cells in mice and decreased the abundance of the stromal markers α-Sma, vimentin, and collagen. Similar effects were seen in mice with xenograft tumors formed from MKN1 cells expressing a kinase-inactive DCLK1 mutant (MKN1D511N). MKN1D511N cells also had reduced in vitro migratory potential and stemness compared with control cells. Mice orthotopically grafted with MKN1 cells overexpressing DCLK1 (MKN1DCLK1) showed increased invasiveness and had a greater incidence of lung metastases compared with those grafted with control MKN1 cells. Mechanistically, we showed that the chemokine CXCL12 acted downstream of DCLK1 in cultured MKN1 cells and in mice subcutaneously implanted with gastric tumors formed by MKN1DCLK1 cells. Moreover, inhibition of the kinase activity of DCLK1 or the expression of DCLK1D511N reversed the pro-tumorigenic and pro-metastatic phenotype. Together, this study establishes DCLK1 as a broadly acting and potentially targetable promoter of GC.

Evaluation of the antioxidant and anti-gastric cancer properties of Pistacia atlantica aqueous extract green-mediated silver nanoparticles

In the presence work, silver nanoparticles were synthesized by a facile green procedure using Pistacia atlantica bark extract as natural reducing and pectin as stabilizing reagent. The physicochemical characteristics of the synthesized Pectin/Ag NPs are further confirmed by several characterization methods such as FT-IR, XRD, FESEM-EDX and TEM analyses. The Fourier transform infrared spectrometer was utilized to investigate the functional groups present in pectin capped silver nanoparticles that were responsible for the capping and remarkably dispersed nanoparticles with no aggregation. The latest research concentrated on the cellular and molecular components. The MTT test was done to assess the effectiveness of the Pectin/Ag NPs nanocomposite on inhibiting human gastric cancer cells and its cytotoxic effects on the treated cells. The evaluation was conducted on healthy (HUVEC) and stomach cancer cells, specifically NCI-N87 and MKN45. The nanocomposite exhibited IC50 values of 75 µg/mL against MKN45 and 152 µg/mL against NCI-N87. A decrease in the viability of gastric cancer cells was noted in the nanocomposite presence, which was dependent on the dosage. Additionally, the nanocomposite triggered a 70–90 % increase in cell apoptosis, resulting in elevated levels of pro-apoptotic markers (Bax and cleaved caspase-8) and reduced levels of the anti-apoptotic marker, Bcl-2. The Pectin/Ag NPs exhibited suppressive properties on colony formation. Our findings suggest that the Pectin/Ag NPs have the ability to enhance p53 expression while reducing the STAT3 expression in the cells that were treated. The findings suggest that STAT3 and p53 are essential factors in the biological responses triggered by the extract in human gastric carcinoma cells. The results suggest that the nanocomposite has the potential to serve as an effective treatment for human gastric cancer cells.

Synthesis and antiproliferative evaluation of new hybrids of piperine and acylhydrazone

Piperine, a natural amide isolated from the genus of Piper, serves as a pharmacophore in medicinal chemistry. In this study, we synthesised and evaluated 18 novel piperine-acylhydrazone hybrids (4a–4r) for their antiproliferative activities in vitro. The structures of these hybrids were validated using 1H,13C NMR, and HR-ESI-MS data. Furthermore, we screened all synthesised compounds for their antiproliferative activities against three human cancer cell lines: FaDu (laryngeal carcinoma cells), HepG2 (hepatoblastoma carcinoma cells), and MGC803 (gastric carcinoma cells). Among them, compound 4o exhibited significantly inhibitory activities against FaDu, HepG2, and MGC803 with IC50 values of 13.85 ± 0.19, 11.02 ± 1.45, and 13.47 ± 3.43 μM, respectively, which was approximately two-fold lower than the positive control cisplatin. These findings suggest that compound 4o has the potential to be promising leads for the design of anti-cancer drugs.

Methynissolin confers protection against gastric carcinoma via targeting RIPK2

Gastric carcinoma (GC) is one of the most common malignant tumors worldwide, and ranks fifth in incidence and top 5 in tumor-associated mortality. Unfortunately, the molecular mechanisms contributing to GC development are still unclear, urgently requiring more studies. It has been proposed that the multifunctional regulator receptor-interacting protein 2 (RIPK2) is both a regulator that induces stomach cancer and its complications such as cachexia. However, the potential molecular function of RIPK2 on regulation of GC is largely unknown. Moreover, 3,9-di-O-methylnissolin, a flavonoid derived from the roots of Astragalus membranaceus, exhibits protective effects against cancer, inflammation, and bacterial infections. Unfortunately the antineoplastic mechanism of oral exposure of such flavonoid are poorly understood. It remains unknown whether 3,9-di-O-methylnissolin is capable of mitigating GC progression, and potential molecular mechanism. This study aims to provide mechanistic evidence that the 3,9-di-O-methylnissolin-triggered mitigation of GC by repressing RIPK2 activity and its downstream ASK1 signaling. The TCGA database, GEO database, subjects with GC phenotype and GC cell lines were used in this work. 3,9-di-O-methylnissolin intervention reduces stomach cancer cell migration, proliferation and invasion in vitro. Also, 3,9-di-O-methylnissolin confers protection against tumor growth in xenograft model in vivo. Mechanistically, on the other hand, in the para-carcinoma tissue, overexpression of RIPK2 reduces lipogenesis and disturbs lipid homeostasis. Overexpression of RIPK2 activates downstream signaling of ASK1, which in turn downregulates PPARα, a master regulator of lipid metabolism. This process results in lower lipogenesis and downregulation of a set of PPARα target genes. Astragalus membranaceus naturally produces 3,9-di-O-methylnissolin, a bioactive substance that when suppression of ASK1 by methylnissolin reduces RIPK2-induced GC and its related cachexia and restores lipid homeostasis. These findings offer important new understandings of stomach cancer and could aid in the development of treatment plans for gastric carcinoma and cachexia related to cancer.

Silver nanoparticles stabilized by chitosan-polyvinyl alcohol polymers mediated by Pistacia extract for treatment of functional dyspepsia and gastric cancer

The impact of the nanoparticles on the dyspepsia mice gut microbiota is evaluated through the utilization of the 16S rRNA technique. Various methods were employed to characterize the NPs. In the textile, culinary, paper, leather, and printing sectors, synthetic dyes are frequently employed as coloring agents. Because these dye molecules are harmful to both the environment and living things, it is difficult to remove them sustainably. Here, we have produced nanoparticles embedded in chitosan-polyvinyl alcohol hydrogel (CS-PVA) by using bark's Pistacia under ultrasonic irradiation. The reduction of Ag + ions into Ag0 NPs was detected by a visual change in the colors. UV–Vis analysis indicated that the characteristic SPR band appeared near ∼440–450 nm. UV/Vis, EDX-elemental mapping, SEM, TEM, ICP-OES, and XRD analysis were applied to characterize the Ag NPs/CS-PVA nanocomposite. The recent study focused on the cellular and molecular aspects. The MTT assay was conducted for 48 h to evaluate the anti-human gastric cancer and cytotoxicity efficacies of the treated cells with nanocomposite. The assessment was performed on normal (HUVEC) and gastric cancer cells, namely MKN45 and NCI–N87. The IC50 values of nanocomposite against MKN45 and NCI–N87 were 180 and 151 μg/mL, respectively. The dose-dependent reduction in malignant gastric cell viability was observed in the nanocomposite presence. Furthermore, the nanocomposite induced cell apoptosis by 40–50%, leading to an increase in the expression of pro-apoptotic markers (Bax and cleaved caspase-8) and a decrease in the expression of the anti-apoptotic marker, Bcl-2. Furthermore, the nanocomposite showed inhibitory effects on colony formation. Our results indicate that the nanocomposite can increase p53 expression and decrease the expression of STAT3 in treated cells. This indicates that p53 and STAT3 play crucial roles in the biological effects induced by the extract in human gastric carcinoma cells. The data from the gut microbiome suggested that nanocomposites have the ability to control the rebalancing of homeostasis and microbiome composition by decreasing the levels of harmful bacteria, and at the same time, increasing the levels of beneficial bacteria. Following the introduction of nanocomposite, there was an observed rise in the levels of gastrointestinal hormones in the serum, including gastrin and motilin, while the levels of vasoactive intestinal peptide decreased. The application of nanocomposite led to an improvement in gastrointestinal movement, encompassing a rise in the rate of transit through the small intestine and the rate of gastric emptying. These findings offer that the Ag NPs/CS-PVA nanocomposite could be a promising anticancer treatment for functional dyspepsia and gastric cancer.

Securinine inhibits carcinogenesis in gastric cancer by targeting AURKA-β-catenin/Akt/STAT3 and the cell cycle pathway

BackgroundGastric cancer (GC) is difficult to treat with currently available treatments. Securinine (SCR) has a lengthy history of use in the treatment of disorders of the nervous system, and its anticancer potential has been gaining attention in recent years. The aim of this study was to explore the repressive effect of SCR on GC and its fundamental mechanism. MethodsThe efficacy of SCR in GC cells was detected by MTT assays. Colony formation, flow cytometry and Transwell assays were used to assess the changes in the proliferation, apoptosis, cell cycle distribution, migration and invasion of GC cells after treatment. AGS (human gastric carcinoma cell)-derived xenografts were used to observe the effect of SCR on tumor growth in vivo. The molecular mechanism of action of SCR in GC was explored via RNA sequencing, bioinformatics analysis, Western blotting, molecular docking, and immunohistochemistry. ResultsSCR was first discovered to inhibit the proliferation, migration, and invasion of GC cells while initiating apoptosis and cell cycle arrest in vitro. It was also established that SCR has excellent anticancer effects in vivo. Interestingly, AURKA acts as a crucial target of SCR, and AURKA expression can be blocked by SCR. Moreover, this study revealed that SCR suppresses the cell cycle and the β-catenin/Akt/STAT3 pathways, which were previously reported to be regulated by AURKA. ConclusionSCR exerts a notable anticancer effect on GC by targeting AURKA and blocking the cell cycle and β-catenin/Akt/STAT3 pathway. Thus, SCR is a promising pharmacological option for the treatment of GC.

Nucleobindin 2 inhibits senescence in gastric carcinoma

Here, we focused on the role of Nucleobindin 2 (NUCB2), a multifunctional protein, in gastric carcinoma (GC) progression. NUCB2 expression was investigated in 150 GC cases (20 non-invasive (pT1) and 130 invasive (pT2/pT3/pT4) tumors) by immunohistochemistry (IHC), and in situ hybridization for detection of the mRNA in 21 cases. Using GC cell lines, we determined whether NUCB2 expression was associated with specific cellular phenotypes. In GC clinical samples, NUCB2 was transcriptionally upregulated when compared to normal tissues. High NUCB2 expression was associated with clinicopathological factors including deep tumor invasion, lymphovascular invasion, lymph node metastasis, and advanced clinical stages, and was a significant independent predictor of unfavorable progression-free survival in 150 non-invasive and invasive GC patients. Similar findings were also evident in 72 invasive GC cases in which patients received post-operative chemotherapy, but not in 58 invasive tumors from patients who did not receive the chemotherapy. In cell lines, NUCB2 knockout inhibited proliferation, susceptibility to apoptosis, and migration capability by inducting cellular senescence; this was consistent with higher proliferation and apoptotic indices in the NUCB2 IHC-high compared to NUCB2 IHC-low GC cases. NUCB2-dependent inhibition of senescence in GC engenders aggressive tumor behavior by modulating proliferation, apoptosis, and migration.

MISP Is Overexpressed in Intestinal Metaplasia and Gastric Cancer.

Gastric cancer is the fifth most common cancer and the fourth cause of global cancer mortality. The identification of new biomarkers and drug targets is crucial to allow the better prognosis and treatment of patients. The mitotic spindle positioning (MISP) protein has the function of correcting mitotic spindle positioning and centrosome clustering and has been implicated in the cytokinesis and migration of cancer cells. The goal of this work was to evaluate the expression and clinical relevance of MISP in gastric cancer. MISP expression was evaluated by immunohistochemistry in a single hospital series (n = 286) of gastric adenocarcinomas and compared with normal gastric mucosa and intestinal metaplasia, a preneoplastic lesion. MISP was detected on the membrane in 83% of the cases, being overexpressed in gastric cancer compared to normal gastric mucosa (n = 10). Its expression was negatively associated with diffuse and poorly cohesive types. On the other hand, it was strongly expressed in intestinal metaplasia where it was associated with MUC2 and CDX2 expression. Furthermore, when we silenced MISP in vitro, a significant decrease in the viability of gastric carcinoma cells was observed. In conclusion, MISP is overexpressed in gastric cancer, being associated with an intestinal phenotype in gastric carcinogenesis and having a role in cellular proliferation.

Abstract 3987: PD-L1 antigen stability using PD-L1 IHC pharmDx on human cancer tissues

Abstract Diagnostic evaluation and selection of potential pembrolizumab-responsive patients is achieved by determining the programmed cell death ligand-1 (PD-L1) expression using the companion diagnostic PD-L1 IHC 22C3 pharmDx assay, for several indications. PD-L1 expression is evaluated by immunohistochemistry (IHC) and is currently the most widely used selective biomarker for response to pembrolizumab anti-PD-1 therapy. Antigen stability on cut tissue sections, also referred to as cut section stability (CSS), and its impact on IHC results is of interest when determining PD-L1 positive or negative status for clinical trials and diagnostic purposes. Since the stability of cut sections from formalin-fixed paraffin-embedded (FFPE) tissue relies on retention of PD-L1 antigenicity following tissue sectioning, the aim of these studies was to measure CSS across multiple tumor indications using combined positive score (CPS). The impact of aged cut sections was evaluated for PD-L1 expression based on pathologist CPS scores of blinded and randomized stained sections. To assess CSS, fresh unstained 4µm cut tissue sections were stored in the dark at 2-8 °C. Staining was performed according to the instructions for use at predefined timepoints. Studies included neoplastic specimens from biliary tract adenocarcinoma (BTAC), cervical cancer (CC), colorectal (CRC) and gastric (GC) carcinoma, esophageal cancer (EC), head and neck squamous cell carcinoma (HNSCC), nasopharyngeal (NPC), ovarian (OC), renal cell (RCC), and triple negative breast (TNBC) carcinoma. Data for each indication and timepoint were used to evaluate average drift in CPS scores over time, starting with scores from a set of respective slides stained at timepoint zero, prior to aging of unstained cut slides. CSS for each specimen within each indication was based on the intersection point of the two-sided 95% confidence interval for the regression line on CPS drift with allowable drift limits. Overall CSS for each indication was defined based on the specimen that exhibited the shortest shelf-life. Linear regression analysis was performed to evaluate average CPS drift over time and define the CSS per indication. This analysis identified the following CSS (in days) for each tumor type when stored at 2-8 °C: 105 (CC), 113 (OC), 115 (BTAC), 135 (EC), 163 (GC), 180 (RCC), 197 (HNSCC), 231 (TNBC), 240 (NPC), and 300 (CRC). The minimal shelf life for unstained cut sections stored at 2-8 °C across the 10 indications in these studies was 105 days, indicating a possible minimum threshold for indications tested when sectioned specimens are stored at 2-8 °C. These data provide high confidence in determining PD-L1 expression on properly stored aged cut sections. Commercial claims may be shorter based on region, as specified in the local instructions for use. Citation Format: Megan Kalpakoff, Emily Olander, Kelci Jones, Stephanie Hund, Tiffany Evans, Joseph Barreto, Deanna Moquin, Grant Toland, Siena Tabuena-Frolli, Kristopher Kersch, Karina Kulangara, Jeanette Musser. PD-L1 antigen stability using PD-L1 IHC pharmDx on human cancer tissues [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3987.

Abstract 697: Enhanced tumor control and survival in solid tumor models following combined low dose radiotherapy and T cell therapy

Abstract Background: Solid tumors remain a significant challenge in cancer therapy due to their resistance to conventional treatments. Chimeric antigen receptor (CAR)-T cell therapy has emerged as a promising approach for treating solid tumors, but its effectiveness is often limited by the poor infiltration of CAR-T cells into the tumor microenvironment. Thus, enhancing a robust infiltration of chimeric antigen receptor T cells into solid tumors is essential for an effective antitumor response and therapeutic success. Methods: In this study, we investigated the combined effects of multiple doses of low-dose radiotherapy (LD-RT) and CAR T-cell therapy on tumor growth and survival using two models of NSG mice implanted with gastric carcinoma (GSU) or pancreatic adenocarcinoma (CAPAN-2) cells. The engineered CAR-T cells were designed to target guanyl cyclase-C (GCC) or mesothelin, respectively. Furthermore, our study employed atomic force microscopy (AFM) in a small cohort to investigate the impact of LD-RT and CAR-T cell therapy on tumor stiffness and plasticity. Results: The synergistic effect of combining low-dose radiotherapy (LD-RT) with T-cell therapy resulted in enhanced tumor control and prolonged survival in mice with tumors, surpassing the outcomes observed with either monotherapy alone. This combined treatment holds promise for improving responses in patients with solid tumors by leveraging LD-RT to enhance the intratumoral infiltration of effector T cells. Our findings suggest that the nanomechanical signature may be a potential biomarker for LD-RT combined CAR T cell therapy in solid tumors. Conclusions: Our findings substantially contribute to treating solid tumors using cell therapies, highlighting the potential for improved infiltration of adoptively transferred T cells following radiotherapy (RT), which can transform existing therapeutic strategies for solid tumors while minimizing toxicity. Citation Format: Nahum Puebla, Gitika Srivastava, Sara Nizzero, Natalie Wall Fowlkes, Hampartsoum Barsoumian, Yun Hu, Carola Leuschner, Thomas Riad, Marko Loparic, Marija Plodinec, James Welsh. Enhanced tumor control and survival in solid tumor models following combined low dose radiotherapy and T cell therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 697.

KLF10/CBS increases the sensitivity of gastric carcinoma cells to methionine restriction by promoting sulfur transfer pathway

Gastric cancer metastasis is a major cause of poor prognosis. Our previous research showed that methionine restriction (MR) lowers the invasiveness and motility of gastric carcinoma. In this study, we investigated the particular mechanisms of MR on gastric carcinoma metastasis. In vitro, gastric carcinoma cells (AGS, SNU-5, MKN7, KATO III, SNU-1, and MKN45) were grown in an MR medium for 24 h. In vivo, BALB/c mice were given a methionine-free (Met−) diet. Transwell assays were used to investigate cell invasion and migration. The amounts of Krüppel like factor 10 (KLF10) and cystathionine β-synthase (CBS) were determined using quantitative real-time PCR and Western blot. To determine the relationship between KLF10 and CBS, chromatin immunoprecipitation and a dual-luciferase reporter experiment were used. Hematoxylin–eosin staining was used to detect lung metastasis. Liquid chromatography–mass spectrometry was used to determine cystathionine content. MR therapy had varying effects on the invasion and migration of gastric carcinoma cells AGS, SNU-5, MKN7, KATO III, SNU-1, and MKN45. KLF10 was highly expressed in AGS cells but poorly expressed in KATO III cells. KLF10 improved MR's ability to prevent gastric carcinoma cell invasion and migration. In addition, KLF10 may interact with CBS, facilitating transcription. Further detection revealed that inhibiting the KLF10/CBS-mediated trans-sulfur pathway lowered Met−‘s inhibitory effect on lung metastasis development. KLF10 transcription activated CBS, accelerated the trans-sulfur pathway, and increased gastric carcinoma cells' susceptibility to MR.

Engineering MnO2 Nanomulberries for Enhancing PTT/PDT Synergistic Cancer Therapy

AbstractConsidering the great catalyzation ability to degrade H2O2 into O2, MnO2 nanoparticles are utilized as nanocarriers in phototherapies for anticancer treatments to overcome the hypoxia tumor microenvironment (TME). However, the confliction of size requirement between promoting tumor delivery and cellular uptake and catalyzing H2O2 degradation limits the functions of MnO2 nanoparticles. Herein, this work presents strategy to cross‐link small‐sized MnO2 nanoparticles, during which the indocyanine green (ICG) is loaded, thus obtaining large‐sized MnO2 nanomulberries (MnINCs) for overcoming the size requirement confliction. The MnINCs present great performances in both photothermal therapy (PTT) and photodynamic therapy (PDT) effects. This work tests the therapeutic efficacy of MnINCs in various human cancer cell lines including human cervical cancer cell line (HeLa), human breast cancer cell line (MCF‐7), human hepatoma cell line (HepG‐2), human gastric carcinoma cell line (MGC803), and a Hela cell‐derived xenograft model. The satisfying growth inhibition effects are observed in all these cell lines and the tumor model. The demonstrations for using MnINCs to overcome the size requirement confliction between promoting tumor delivery and cellular uptake and catalyzing H2O2 degradation highlight the promising application potentials of the clustering strategy for developing innovative treatments in cancer therapy.

Retraction Note: Lidocaine inhibits growth, migration and invasion of gastric carcinoma cells by up-regulation of miR-145

Retraction Note: Lidocaine inhibits growth, migration and invasion of gastric carcinoma cells by up-regulation of miR-145