Abstract Background PIEZO1 works differently in different cancers and at different stages of development. The objective of the current study was to explore the function and underlying mechanism of PIEZO1 in lung adenocarcinoma (LUAD) cells. Methods Different LUAD cell lines were treated with PIEZO1 inhibitor (GsMTx4) and agonist (Yoda1), and the expression of PIEZO1 in LUAD cells was detected using real‐time quantitative PCR (RT‐qPCR) and western blotting. The effects of PIEZO1 on invasion, migration and epithelial‐mesenchymal transition (EMT) markers protein expression of LUAD cells were detected using the MTT assay, flow cytometry, transwell assay, wound‐healing assay, and western blotting. Reactive oxygen species (ROS) agonists (BAY 87–2243) and inhibitors (NAC) and Wnt/β‐catenin pathway inhibitors (iCRT3) were selected to treat A549 cells to investigate the mechanism of PIEZO1 on ROS production and Wnt/β‐catenin expression in A549 cells. Results In A549, NCI‐H1395, and NCI‐H1975 cells, GsMTx4 promoted cell proliferation, invasion, migration, upregulated EMT‐related marker protein expression, and inhibited cell apoptosis, while Yoda1 exerted effects opposite to those of GsMTx4. In A549 cells, GsMTx4 can reduce ROS production, it also inhibited ROS production, apoptosis, and downregulated proapoptotic markers induced by BAY 87–2243. Importantly, BAY 87–2243 blocked the effect of GSMTX4‐induced Wnt/β‐catenin overexpression. Similarly, Yoda1 can reduce the effect of NAC. In addition, iCRT3 can block the upregulation of EMT‐related marker proteins by GsMTx4, and increase apoptosis and decrease cell invasion and migration. Conclusion In summary, PIEZO1 acts as a cancer suppressor by regulating the ROS/Wnt/β‐catenin axis, providing a new perspective on the role of mechanosensitive channel proteins in cancer.
Abstract Background: Hepatocellular carcinoma (HCC) is the third leading cause of cancer death globally. Recurrence risks following curative resection remain high, ~50% after three years and 75-100% over five years. A biomarker for HCC recurrence is urgently needed to help lead treatment strategies. We previously showed that hepatic γ-hydroxy-1, N2-propano-2′-deoxyguanosine (γ-OHPdG), a DNA adduct derived from lipid peroxidation, increased during hepatocarcinogenesis. Furthermore, in a retrospective study, higher γ-OHPdG levels in post-surgical liver tumor tissues were associated with poorer survival (p<0.0001) and shorter recurrence-free survival (p=0.007), suggesting that it may be a prognostic biomarker for HCC (Hepatology 2018). In this study, we aimed to test γ-OHPdG detected in livers after curative resection as a recurrence biomarker in a prospective study and, in addition, we developed a new non-invasive method for γ-OHPdG in circulating tumor cells (CTCs). This multicenter study seeks to validate γ-OHPdG as a biomarker for HCC recurrence. Methods: A total of 28 HCC patients undergoing hepatectomy at MedStar/Georgetown University Hospital, Johns Hopkins University Hospital, and the University of Maryland Medical Center were enrolled. γ-OHPdG was detected in DNA isolated from hepatic tumors and non-tumors by a previous liquid chromatograph-tandem mass spectrometry (LC-MS/MS) method and in HCC CTCs isolated from blood samples. CTCs were isolated using hepatocyte-specific rabbit anti-asialoglycoprotein-1 (ASGPR-1), followed by staining with mouse anti-γ-OHPdG antibodies. Clinical outcomes were correlated with γ-OHPdG in liver tissues and CTCs. Results: In our current cohort of 28 patients (mean age: 64.7 years; 82% male), five patients experienced HCC recurrence, with an estimated progression-free survival (PFS) rate of 85% over 8 months. γ-OHPdG levels (adducts/109 nucleotides) detected by LC-MS/MS varied widely in tumor tissues (5-56, mean: 11.8) and non-tumor tissue (7-71, mean: 20.6). Preliminary analysis showed shorter PFS associated with γ-OHPdG in non-tumors (cutoff: 16, p=0.0271). γ-OHPdG (arbitrary units x107) in CTCs also varied widely in the nucleus (0.95-18.84, mean: 2.85) and in the whole cell (0.16- 52.18, mean: 9.72). Total CTC γ-OHPdG intensity in both the nucleus (p=0.006) and in the whole cell (p=0.005) was associated with its levels in non-tumor tissue. Furthermore, a shorter PFS was associated with CTC count (cutoff: 270 cells, p=0.01), and total CTC whole cell γ-OHPdG intensity (cutoff: 21.17 × 107 arbitrary units, p=0.002). Conclusion: Preliminary results suggest that γ-OHPdG, measured in tissues by LC-MS/MS and in blood by CTC, predicts HCC recurrence. Once evaluated in all enrolled subjects, multiple variant analyses will be carried out to include stage, AFP, grade of differentiation, vascular invasion on surgical samples, and status of viral hepatitis infection. Citation Format: Mark Kuo, Merve Ozge Aktop, Elie Ghabi, Mahmoud A. Ouf, Margaret Carder, Vinona Muralidaran, Jhalen Ascue, Marketa Hlouskova, Pengfei Wu, Guang Cheng, Stephen S. Hecht, Hong-Bin Fang, Nader Hanna, Jin He, Alexander H. Kroemer, Monika Aggarwal, Aiwu R. He, Fung-Lung Chung. Detection of γ-OHPdG as a hepatocellular carcinoma recurrence biomarker by CTCs and LC-MS/MS [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 7665.
Colon cancer stem cell (cCSC) is considered as the seed cell of colon cancer initiation and metastasis. Cyclooxygenase-2 (COX2), a downstream target of NFκB, is found to be essential in promoting cancer stem cell renewal. However, how COX2 is dysregulated in cCSCs is largely unknown. In this study, we found that the expression of transcription factor FOXP3 was much lower in the spheroids than that in the parental tumor cells. Overexpression of FOXP3 significantly decreased the numbers of spheres, reduced the side population. Accordingly, FOXP3 expression decreased the tumor size and weight in the xenograft model. The tumor inhibitory effects of FOXP3 were rarely seen when COX2 was additionally knocked down. Mechanically, FOXP3 transcriptionally repressed COX2 expression via interacting with and thus inhibiting p65 activity on the putative NFκB response elements in COX2 promoter. Taken together, we here revealed possible involvement of FOXP3 in regulating cCSC self-renewal via tuning COX2 expression, and thus providing a new target for the eradication of colon cancer stem cells.
After the Era of Economic Crisis, if an enterprise want to win the advantageous opportunity, it must have reliable supply chain partners. So the research of evaluation on supply chain partners has become hot contens of supply chain management. Aiming at this problem, this paper proposes using entropy theory to evaluate candidate partners. Entropy value method is a kind of objective method, suitable to find inner link among indexes. It can also avoid subjective deviation. This method has certain practical significance through empirical.
In the present study, the influence of the variation of immersion fluid volume (or air-drying time) on skull resistivity was studied. The results showed that the skull resistivity increased significantly with the increasing of air-drying time. For air-drying time of 10 min, the skull resistivity increased approximately 2 times, and for 30 min and 60 min, the skull resistivity increased significantly about 7 times and 19 times. This study suggests that we should pay more attention to the humidity of experimental environment to keep the natural immersion fluid from volatilizing in the measurement on skull resistivity. Preserving the freshly excised skull samples in gauze soaked with physiological saline can effectively keep the immersion fluid and maintain the natural physiological status.
AIMTo investigate the effects of matrine on the proliferation of human glioma cell line BT325. METHODS MTT was used to measure the levels of the proliferation of BT325 cultured with matrine in different concentrations. The effects of matrine on cell cycle of BT325 were observed by FCM. The morphological change of BT325 cell was detected by electronic microscopy. RESULTS The proliferation of BT325 was obviously inhibited by matrine in a dose dependent manner. The inhibitory rate came to the peak at (32 1±1 1)%, when cultured with matrine at 0 5 g·L -1 . The outcome of FCM showed that the apoptotic cell rate was 23 9%. The morphological changes of apoptosis were also found by electronic microscopy. CONCLUSION Matrine can inhibit the proliferation of BT325 and induce the apoptosis of the cells.
Previous studies have demonstrated that the reaction of crotonaldehyde with DNA produces Michael addition products, and these have been detected in human tissues as well as tissues of untreated laboratory animals. A second class of crotonaldehyde−DNA adducts releases 2-(2-hydroxypropyl)-4-hydroxy-6-methyl-1,3-dioxane (paraldol, 12) upon hydrolysis, and these adducts are quantitatively more significant than the Michael addition adducts in vitro. In this study, we demonstrate that the major source of the paraldol-releasing DNA adducts of crotonaldehyde is a Schiff base. Reaction of crotonaldehyde with DNA, followed by treatment with NaBH3CN and enzyme hydrolysis, resulted in the formation of N2-(3-hydroxybutyl)dG (10), identified by its UV, MS, and proton NMR. Reactions of crotonaldehyde or paraldol with dG demonstrated that the Schiff base precursor to N2-(3-hydroxybutyl)dG is N2-(3-hydroxybutylidene)dG (7), identified by UV, LC−APCI-MS, and MS/MS. Four isomers of N2-(3-hydroxybutylidene)dG were observed. The (R)- and (S)-isomers were identified by reactions of chiral paraldol with dG; each existed as a pair of interconverting (E)- and (Z)-isomers. These data indicate that the structure of the major Schiff base DNA adduct in crotonaldehyde-treated DNA is N2-(3-hydroxybutylidene)dG (7). This adduct is unstable at the nucleoside level and accounts for more than 90% of the paraldol released from crotonaldehyde-treated DNA. However, the adduct is stable in DNA and therefore is a likely companion to the Michael addition adducts in human DNA.
A practical three-step synthetic approach to gimeracil in a 68% overall yield is described, using 2,4-dimethoxypyridine as the starting material with 3,5-dichloro-2,4-dimethoxypyridine and 3,5-dichloro-2,4-dihydroxypyridine as intermediates. The advantages of this procedure include short reaction steps, simple operation and good yield.
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