Regulation of the RB1 Gene through DNMT1 by SGI-1027 and its Impact on the Growth and Metastasis of Gastric Cancer Cells.

BACKGROUND: SGI-1027 is a recognized inhibitor of DNA methyltransferase 1 (DNMT1), and earlier investigations have indicated an inverse correlation between dysregulated DNMT1 expression in gastric cancer (GC) and retinoblastoma 1 (RB1) gene expression. Despite this knowledge, the precise mechanisms underlying the action of SGI-1027 in GC cells remain inadequately comprehended. The primary objective of this study is to elucidate the impact of SGI-1027 on the behavior of GC cells, encompassing aspects such as growth and metastatic potential, by intervening in DNMT1, thereby influencing the regulation of RB1 gene expression. METHOD: The acquisition of the normal gastric mucosal cell line GES-1 and the human gastric cancer cell line MKN45 was followed by employing Western blot (WB) and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) techniques to evaluate the expression levels of RB1 and DNMT1 in these two cell lines. Subsequently, the MKN45 cell line was cultured in medium containing varying concentrations of SGI-1027, and the impact of SGI-1027 on the regulation of RB1 and DNMT1 in GC cells was reassessed using WB and qRT-PCR techniques. To scrutinize the effect of SGI-1027 on GC cells, we utilized the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MTT) assay to determine cell proliferation and performed Transwell experiments to assess cell migration and invasion capabilities. Throughout this process, we also employed WB to assess the levels of cell cycle-associated proteins (Cyclin D1, Cyclin E1, and Cyclin B1) and proteins related to apoptosis (BCL-2 associated protein X apoptosis regulator (BAX) and B-cell lymphoma 2 apoptosis regulator (BCL-2)). Furthermore, we injected the MKN45 cell line and MKN45 cell line cultured with the optimal concentration of SGI-1027 for 5 days and 10 days into mice subcutaneously and through the tail vein, dividing them into the Model group, Model+SGI-1027 5d group, and Model+SGI-1027 10d group. We monitored changes in tumor size and volume in mice, and tumor tissues as well as lung tissues were collected for hematoxylin and eosin (HE) staining. Finally, DNMT1 expression levels in GC tissues were detected using both WB and immunohistochemistry (IHC) techniques. Additionally, RB1 expression levels in GC tissues were assessed using WB. RESULT: In contrast to GES-1 cells, MKN45 cells displayed a distinctive profile characterized by increased DNMT1 expression and decreased RB1 expression (p < 0.05). However, upon the introduction of SGI-1027, a notable decrease in DNMT1 levels within GC cells was observed, concomitant with an elevation in RB1 gene expression, with 25 µmol/L SGI-1027 identified as the optimal concentration (p < 0.05). Functional assays demonstrated that SGI-1027-treated GC cells exhibited pronounced features of inhibited proliferation, migration, and invasion when compared to untreated MKN45 cells (p < 0.05). Moreover, in SGI-1027-treated GC cells, the levels of Cyclin D1, Cyclin E1, Cyclin B1, and BCL-2 were significantly reduced, while the expression level of BAX increased (p < 0.05). Notably, the most pronounced impact was observed at 25 µmol/L SGI-1027, further underscoring its regulatory effects on tumor cell behavior (p < 0.05). In animal experiments, the Model group exhibited a substantial increase in tumor volume, with HE staining results indicating extensive necrosis in most gastric tissues and noticeable signs of lung metastasis, accompanied by increased DNMT1 expression and decreased RB1 gene expression. In contrast, the SGI-1027 group displayed a reduction in gastric tumor volume, decreased necrosis, and reduced lung tumor metastasis (p < 0.05). Additionally, the expression of DNMT1 was significantly reduced in SGI-1027-treated GC cells, while RB1 expression increased (p < 0.05), further confirming the inhibitory effects of SGI-1027 on tumor growth and metastasis. CONCLUSIONS: SGI-1027 effectively hinders the proliferation and dissemination of GC cells by downregulating DNMT1 and promoting the expression of RB1.

Kaempferol-induced mitochondrial damage promotes NF-κB-NLRP3-caspase-1 signaling axis-mediated pyroptosis in gastric cancer cells.

GC is a gastrointestinal tumor with high morbidity and mortality. Owing to the high rate of postoperative recurrence associated with GC, the effectiveness of radiotherapy and chemotherapy may be compromised by the occurrence of severe undesirable side effects. In light of these circumstances, KP, a flavonoid abundantly present in diverse herbal and fruit sources, emerges as a promising therapeutic agent with inherent anti-tumor properties. This study endeavors to demonstrate the therapeutic potential of KP in the context of GC while unraveling the intricate underlying mechanisms. Notably, our investigations unveil that KP stimulation effectively promotes the activation of NLRP3 inflammatory vesicles within AGS cells by engaging the NF-κB signaling pathway. Consequently, the signal cascade triggers the cleavage of Caspase-1, culminating in the liberation of IL-18. Furthermore, we ascertain that KP facilitate AGS cell pyroptosis by inducing mitochondrial damage. Collectively, our findings showcase KP as a compelling candidate for the treatment of GC-related diseases, heralding new possibilities for future therapeutic interventions.

Baicalin Induces Gastric Cancer Cell Pyroptosis through the NF-κB-NLRP3 Signaling Axis.

Pyroptosis, a highly regulated form of cell death, could hold the key to revolutionizing cancer treatment. With cancer posing a significant global health challenge due to its high morbidity and mortality rates, exploring unconventional therapeutic approaches becomes imperative. Chinese medicine, renowned for its holistic principles, presents intriguing possibilities for treating gastric cancer (GC). Notably, baicalin, a prominent component found in the traditional Chinese herb Scutellaria baicalensis Georgi, has shown promising clinical potential in gastric cancer treatment.To shed light on this intriguing phenomenon, a multidisciplinary approach was undertaken, combining systems biology, bioinformatics, and in vitro studies. The primary objective was to unravel the intricate workings underlying baicalein's ability to promote gastric cancer cell pyroptosis.The findings from this comprehensive study unveiled an essential signaling axis involving NF-κB-NLRP3, which plays a pivotal role in the process of baicalein-induced pyroptosis in gastric cancer cells. As the investigation progressed, it became evident that baicalein exhibited a remarkable capability to reverse the effects of the NLRP3 inhibitor, MCC950 Sodium. Excitingly, the efficacy of cell pyroptosis induction by baicalein demonstrated a discernible dose-dependent relationship, showcasing its potential as a valuable therapeutic agent.The complex nature of these findings underscores the intricate interplay between baicalein, NF-κB-NLRP3 signaling, and gastric cancer cell pyroptosis. As the scientific community delves deeper into the world of Pyroptosis and its therapeutic implications, baicalein's potential as a game-changer in the fight against gastric cancer becomes increasingly evident.

Integrating HPLC-Q-TOF-MS/MS, network pharmacology and experimental validation to decipher the chemical substances and mechanism of modified Gui-shao-liu-jun-zi decoction against gastric cancer.

Background and aim: Gastric cancer (GC) is a common malignant tumor worldwide. Modified Gui-shao-liu-jun-zi decoction (mGSLJZ) is a clinically effective traditional Chinese medicine (TCM) compound in GC treatment. This study aimed to analyze main chemical substances of mGSLJZ and investigate active ingredients and molecular mechanism of mGSLJZ against GC. Experimental procedure: HPLC-Q-TOF-MS/MS was used to analyze chemical substances of mGSLJZ, and potential active ingredients were screened from TCMSP. The target set of mGSLJZ for GC was obtained based on SwissTargetPrediction. The PPI network was constructed to screen out core targets. GO and KEGG enrichment analyses were conducted to identify BPs, CCs, MFs and pathways. The "active ingredient-core target-pathway" regulatory network was constructed to obtain core substances. Subsequently, Oncomine, Proteinatlas and molecular docking were performed to validate these findings. The cell experiments were conducted to confirm the anti-GC effects of mGLSJZ. Results and conclusion: Forty-one potential active ingredients were filtered out from 120 chemical substances in mGSLJZ, including various organic acids and flavonoids. The top 10 key targets, 20 related pathways and 6 core medicinal substances were obtained based on network pharmacology analysis. Molecular docking results indicated that the core substances and key targets had good binding activities. The cell experiments validated that mGSLJZ and the core substances inhibited the proliferation in multiple GC cells and that mGLSJZ restrained the migration of GC. Meanwhile, the top 5 targets and top 2 pathways were verified. The rescue experiments demonstrated that mGSLJZ suppressed the proliferation and migration of GC through the PI3K/AKT/HIF-1 pathway.

The inhibitory effect and mechanism of Yi-qi-hua-yu-jie-du decoction on the drug resistance of gastric cancer stem cells based on ABC transporters.

BACKGROUND: The drug resistance of tumor stem cells is an obstacle in gastric cancer (GC) treatment and the high expression of ABC transporters is a classic reason for drug resistance. This study aimed to construct a reliable GC drug-resistant stem cell model and explore the inhibitory effect and mechanism of Yi-qi-hua-yu-jie-du medicated serum (YQHY) on the drug resistance of GC stem cells based on ABC transporters. METHODS: The tumor stemness biomarker CD44 was primary identification from WGCNA. The magnetic-activated cell sorting (MACS) method was used to separate CD44( +)BGC823/5-Fu (BGC823/5-Fu-CSCs) cells and the stemness characteristics were verified from multiple dimensions. Then, the drug resistance index and expression of ABC transporter genes MDR1 and MRP1 were detected in CD44(-)/CD44(+) cells. The inhibition and apoptosis rates of the cells administrated with YQHY or/and 5-Fu were calculated to confirm that YQHY can suppress the drug resistance of BGC823/5-Fu-CSCs. Afterwards, the effects of YQHY on the expression of MDR1 and MRP1 and the activation of the PI3K/Akt/Nrf2 pathway were observed. Finally, under the administration of IGF-1 (the activator of PI3K/Akt pathway) and Nrf2 siRNA, the mechanism of YQHY on reversing the drug resistance of BGC823/5-Fu-CSCs through inhibiting the expression of MDR1 and MRP1 via PI3K/Akt/Nrf2 was verified. RESULTS: CD44 was a reliable GC stemness biomarker and can be applied to construct the drug-resistant GC stem cell model CD44(+)BGC823/5-Fu. The growth rate, cell proliferation index, soft agar colony formation, expression of stemness specific genes and tumorigenesis ability of CD44(+)BGC823/5-Fu cells were significantly higher than those of CD44(-)BGC823/5-Fu cells. BGC823/5-Fu-CSCs exhibited strong drug resistance to 5-Fu and high expression of ABC transporter genes MDR1 and MRP1 compared to CD44(-) cells. YQHY increased the inhibition and apoptosis rates to efficiently inhibit the drug resistance of BGC823/5-Fu-CSCs. Meanwhile, it suppressed the expression of MDR1 and MRP1 and restrained the activation of PI3K/Akt/Nrf2 signaling pathway. Finally, it was found that IGF-1 partially restored the activation of PI3K/Akt/Nrf2 pathway, alleviated the inhibition of MDR1 and MRP1, blocked the proliferation-inhibitory and apoptosis-promotion effects. YQHY and si-Nrf2 synergistically suppressed the MDR1/MRP1 expression and the drug resistance of BGC823/5-Fu-CSCs. CONCLUSIONS: CD44 was a reliable GC stemness biomarker, and the high expression of ABC transporter genes MDR1 and MRP1 was an important feature of drug-resistant stem cells. YQHY inhibited the MDR1 and MRP1 expression via PI3K/Akt/Nrf2 pathway, thus reversing the drug resistance of BGC823/5-Fu-CSCs.

Characteristics of immunophenotypes and immunological in tumor microenvironment and analysis of immune implication of CXCR4 in gastric cancer.

The formation of gastric cancer (GC) is a complicated process involving multiple factors and multiple steps. The tumor-immune microenvironment is essential for the growth of GC and affects the prognosis of patients. We performed multiple machine learning algorithms to identify immunophenotypes and immunological characteristics in GC patients' information from the TCGA database and extracted immune genes relevance of the GC immune microenvironment. C-X-C motif chemokine receptor 4 (CXCR4), belongs to the C-X-C chemokine receptor family, which can promote the invasion and migration of tumor cells. CXCR4 expression is significantly correlated to metastasis and the worse prognosis. In this work, we assessed the condition of immune cells and identified the connection between CXCR4 and GC immune microenvironment, as well as the signaling pathways that mediate the immune responses involved in CXCR4. The work showed the risk scores generated by CXCR4-related immunomodulators could distinguish risk groups consisting of differential expression genes and could use for the personalized prognosis prediction. The findings suggested that CXCR4 is involved in tumor immunity of GC, and CXCR4 is considered as a potential prognostic biomarker and immunotherapy target of GC. The prognostic immune markers from CXCR4-associated immunomodulators can independently predict the overall survival of GC.