[Association of Serine/Threonine Phosphoprotein Phosphatase 4C Expression With Prognosis of Gastric Cancer].

Objective To investigate the expression level of serine/threonine phosphoprotein phosphatase 4C(PPP4C)in gastric cancer,and analyze its relationship with prognosis and the underlying regulatory mechanism.Methods The clinical data of 104 gastric cancer patients admitted to the First Affiliated Hospital of Bengbu Medical College between January 2012 and August 2016 were collected.Immunohistochemical staining was employed to determine the expression levels of PPP4C and Ki-67 in the gastric cancer tissue.The gastric cancer cell lines BGC823 and HGC27 were cultured and transfected with the vector for PPP4C knockdown,the vector for PPP4C overexpression,and the lentiviral vector(control),respectively.The effects of PPP4C on the cell cycle and proliferation were analyzed and the possible regulatory mechanisms were explored.Results PPP4C was highly expressed in gastric cancer(P<0.001),and its expression promoted malignant progression of the tumor(all P<0.01).Univariate and Cox multivariate analysis clarified that high expression of PPP4C was an independent risk factor affecting the 5-year survival rate of gastric cancer patients(P=0.003).Gene ontology and Kyoto encyclopedia of genes and genomes enrichment analysis suggested that PPP4C may be involved in the cell cycle.The correlation analysis showed that the expression of PPP4C was positively correlated with that of Ki-67 in gastric cancer(P<0.001).The up-regulation of PPP4C expression increased the proportion of tumor cells in the S phase,alleviated the G2/M phase arrest,and promoted the proliferation of gastric cancer cells and the expression of cyclin D1 and cyclin-dependent kinase 6(CDK6)(all P<0.05).The down-regulation of PPP4C decreased the proportion of gastric cancer cells in the S phase,promoted G2/M phase arrest,and inhibited cell proliferation and the expression of cyclin D1,CDK6,and p53(all P<0.05).p53 inhibitors promoted the proliferation of BGC823 and HGC27 cells in the PPP4C knockdown group(P<0.001,P<0.001),while p53 activators inhibited the proliferation of BGC823 and HGC27 cells in the PPP4C overexpression group(P<0.001,P=0.002).Conclusions PPP4C is highly expressed in gastric cancer and affects the prognosis of the patients.It may increase the proportion of gastric cancer cells in the S phase and alleviate the G2/M phase arrest by inhibiting p53 signaling,thereby promoting cell proliferation.

Phosphoglycerate-kinase-1 Is a Potential Prognostic Biomarker in HNSCC and Correlates With Immune Cell Infiltration.

BACKGROUND/AIM: Head and neck squamous cell carcinoma (HNSCC) is the sixth leading cancer worldwide, with a high recurrence rate and a low cure rate. Phosphoglycerate kinase 1 (PGK1), an essential enzyme in the aerobic glycolysis pathway, is a prognostic marker for a variety of cancers. However, it remains unclear whether a PGK1-based immune signature can be used as a prognostic biomarker in HNSCC patients. MATERIALS AND METHODS: We explored the potential oncogenic mechanisms of PGK1 by multiple bioinformatics analyses combined with multiple databases, including the correlation between PGK1 and prognosis, and the infiltration of immune cells in HNSCC. Functional enrichment analyses were further performed to investigate the potential role of PGK1 in HNSCC. RESULTS: The expression of PGK1 was significantly higher in HNSCC tissues compared to normal tissues. High expression of PGK1 was associated with poor prognosis in HNSCC, and multivariate cox regression analysis showed that PGK1 could be an independent prognostic factor in HNSCC. Pathway analysis revealed that PGK1 may regulate the pathogenesis of HNSCC through the immune signaling pathway. Moreover, PGK1 expression significantly correlated with the infiltration level of 16 types of immune cells. CONCLUSION: The current study reports that PGK1 expression was increased in HNSCC and that high PGK1 expression was closely associated with poor prognosis and immune cell infiltration, which could serve as a promising independent prognostic biomarker and potential immunotherapeutic target for HNSCC.

New Type of Tannins Identified from the Seeds of Cornus officinalis Sieb. et Zucc. by HPLC-ESI-MS/MS.

There is a lack of information on the compound profile of Cornus officinalis Sieb. et Zucc. seeds. This greatly affects their optimal utilization. In our preliminary study, we found that the extract of the seeds displayed a strong positive reaction to the FeCl3 solution, indicating the presence of polyphenols. However, to date, only nine polyphenols have been isolated. In this study, HPLC-ESI-MS/MS was employed to fully reveal the polyphenol profile of the seed extracts. A total of 90 polyphenols were identified. They were classified into nine brevifolincarboxyl tannins and their derivatives, 34 ellagitannins, 21 gallotannins, and 26 phenolic acids and their derivatives. Most of these were first identified from the seeds of C. officinalis. More importantly, five new types of tannins were reported for the first time: brevifolincarboxyl-trigalloyl-hexoside, digalloyl-dehydrohexahydroxydiphenoyl (DHHDP)-hexdside, galloyl-DHHDP-hexoside, DHHDP-hexahydroxydiphenoyl(HHDP)-galloyl-gluconic acid, and peroxide product of DHHDP-trigalloylhexoside. Moreover, the total phenolic content was as high as 79,157 ± 563 mg gallic acid equivalent per 100 g in the seeds extract. The results of this study not only enrich the structure database of tannins, but also provide invaluable aid to its further utilization in industries.

[Prognostic Value of the Expression of Myeloid Leukemia Factor 1-Interacting Protein in Gastric Cancer and Its Regulatory Role in Tumor Progression].

Objective: To investigate the prognostic value of the expression of myeloid leukemia factor 1-interacting protein (MLF1IP) in gastric cancer tissue and its regulatory role in tumor progression. Methods: Gene Expression Omnibus (GEO) database was used to analyze the expression level of MLF1IP in tumor tissues of gastric cancer patients. Kaplan-Meier Plotter database was used to analyze the relationship between MLF1IP expression level and patient prognosis. We conducted a retrospective analysis of 108 gastric cancer patients who had undergone radical surgery at our hospital between January 2015 and December 2015. The expression of MLF1IP in gastric cancer tissue and adjacent tissues was examined. We analyzed the relationship between MLF1IP and the clinicopathological parameters of gastric cancer patients and its impact on the long-term prognosis of gastric cancer patients. Univariate and multivariate regression analyses were done to identify the risk factors affecting the long-term prognosis of gastric cancer patients. The assessment value of MLF1IP for long-term prognosis of gastric cancer was analyzed with ROC curve. The effects of MLF1IP on the proliferation, migration, and invasion of gastric cancer cells were analyzed in vitro with gastric cancer cell line (MGC803). A xenograft tumor model was established with nude mice to analyze in vivo the effect of MLF1IP on tumor growth. Results: The results of the gastric cancer cohort GSE29272 of GEO database showed that the expression level of MLF1IP in gastric cancer tissues was significantly higher than that in normal tissues ( P<0.05). Analysis with Kaplan-Meier Plotter database indicated that high MLF1IP expression was correlated with poor prognosis in gastric cancer patients. Immunohistochemical analysis showed that the expression level of MLF1IP in gastric cancer tissues was higher than that in adjacent tissues ( P<0.05). Correlation analysis showed that the MLF1IP level in gastric cancer tissue was positively correlated with Ki67 ( r=0.609, P<0.01), peripheral blood carcinoembryonic antigen (CEA) ( r=0.572, P<0.01) and carbohydrate antigen 19-9 (CA19-9) ( r=0.623, P<0.01). Kaplan-Meier (K-M) survival analysis showed that the 5-year survival rate of patients in the MLF1IP high expression group was significantly lower than that in the MLF1IP low expression group ( P<0.01). Cox regression analysis showed that independent risk factors for 5-year survival after radical gastrectomy for gastric cancer included the expression of MLF1IP ( HR=2.508, 95% CI: 1.259-4.999), CEA≥5 µg/L ( HR=2.171, 95% CI: 1.152-4.092), CA19-9≥37 kU/L ( HR=2.401, 95% CI: 1.094-5.269), and T3-T4 stages ( HR=2.779, 95% CI: 1.049-7.358) and N2-N3 stages ( HR=2.072, 95% CI: 1.100-3.904). ROC analysis showed that the sensitivity, specificity, and accuracy of MLF1IP (the cut-off value was 3.00 relative protein expression level) in assessing the 5-year survival rate after radical gastrectomy for gastric cancer was 75.00%, 76.92%, and 76.2%, respectively ( P<0.05). CCK-8, Transwell assay, and scratch assays showed that in vitro knocking down of MLF1 IP gene expression significantly inhibited the proliferation, migration and invasion of gastric cancer cells. Subcutaneous tumor xenograft experiment in nude mice showed that knocking down MLF1 IP gene significantly inhibited tumor growth. Conclusion: Increased expression of MLF1IP in gastric cancer tissue, which may be involved in the malignant activities of proliferation, migration, and invasion of gastric cancer cells, has a certain predictive value for poor prognosis.

Epigallocatechin Gallate Attenuates Gentamicin-Induced Nephrotoxicity by Suppressing Apoptosis and Ferroptosis.

Gentamicin (GEN) is a kind of aminoglycoside antibiotic with the adverse effect of nephrotoxicity. Currently, no effective measures against the nephrotoxicity have been approved. In the present study, epigallocatechin gallate (EG), a useful ingredient in green tea, was used to attenuate its nephrotoxicity. EG was shown to largely attenuate the renal damage and the increase of malondialdehyde (MDA) and the decrease of glutathione (GSH) in GEN-injected rats. In NRK-52E cells, GEN increased the cellular ROS in the early treatment phase and ROS remained continuously high from 1.5 H to 24 H. Moreover, EG alleviated the increase of ROS and MDA and the decrease of GSH caused by GEN. Furthermore, EG activated the protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). After the treatment of GEN, the protein level of cleaved-caspase-3, the flow cytometry analysis and the JC-1 staining, the protein levels of glutathione peroxidase 4 (GPX4) and SLC7A11, were greatly changed, indicating the occurrence of both apoptosis and ferroptosis, whereas EG can reduce these changes. However, when Nrf2 was knocked down by siRNA, the above protective effects of EG were weakened. In summary, EG attenuated GEN-induced nephrotoxicity by suppressing apoptosis and ferroptosis.

The study of Raddeanin A cerebrovascular endothelial cell trafficking through P-glycoprotein.

As one of the natural triterpenoids isolated from Anemone Raddeana Regel, Raddeanin A (RA) has been confirmed to possess therapeutic effects against multiple tumorigeneses, especially for the onset of glioblastoma and growth in human brains. However, the mechanism by which this happens remains poorly understood in terms of the vascular endothelium trafficking routine of RA through the brain-blood barrier (BBB). To seek such answers, human brain microenvironment endothelial cells (HBMECs) were used to stimulate the microenvironment in vitro, and to explore the intracellular accumulation of RA. The results of this experiment illustrated that RA has a relative moderate transport affinity for such cells. The kinetic parameter Km was 37.01 ± 2.116 µM and Vmax was 9.412 ± 0.1375 nM/min/mg of protein. Interestingly, protein downregulation of P-glycoprotein (P-gp, ABCB1/MDR1) significantly activated RA transmembrane activity, which proves that P-gp is responsible for RA cellular trafficking. In addition, the selective non-specific inhibitor, LY335979 increased either RA or the classical substrate of P-gp, digoxin, intracellular accumulation by restricting the transporter's function but without jeopardizing cytomembrane proteins. Moreover, a decrease in the expression or activity of P-gp triggered RA drug resistance to HBMECs. In summary, our data showed that both the expression and function of P-gp are all necessary for RA transmembrane trafficking through cerebrovascular endothelial cells. This study provides significant evidence for the presence of a connection between RA transport and P-gp variation during drug BBB penetration. It is also suggesting some vital guidance on the RA pharmacodynamic effect in human brains.

Long noncoding RNA AC073284.4 suppresses epithelial-mesenchymal transition by sponging miR-18b-5p in paclitaxel-resistant breast cancer cells.

Breast cancer (BC) is the most prevalent malignant cancer in the world, is the leading cause of cancer-related death female. Recently, there is accumulating evidence that long noncoding RNAs (lncRNAs) might as an important role in the progression of BC. (epithelial-mesenchymal transition (EMT) is considered to play a vital role in tumor cells migration and invasion. Nevertheless, the entire biological mechanisms and functions of lncRNAs in tumor migration, invasion, and EMT remain uncertain. In the present research, we observed that the expression of lncRNA AC073284.4 was downregulated in BC paclitaxel-resistant (PR) cells (MCF-7/PR) and tissues. Bioinformatics analysis predicted that miR-18b-5p was a direct target of AC073284.4, which has been validated by dual-luciferase reporter gene assay. We further proved that AC073284.4 could directly bind to miR-18b-5p and relieve the suppression for dedicator of cytokinesis protein 4 (DOCK4). Furthermore, the underlying functional experiments demonstrated that AC073284.4 might sponge miR-18b-5p to attenuate the invasion, metastasis, and EMT of BC cell through upregulating DOCK4 expression. In summary, AC073284.4 might serve as a competing endogenous RNA (ceRNA) in BC progression via modulating miR-18b-5p/DOCK4 axis, which weakens EMT and migration of BC. These results suggesting that AC073284.4 might function as a potential novel diagnostic biomarker in the progression of BC.

The N-terminal polypeptide derived from viral macrophage inflammatory protein II reverses breast cancer epithelial-to-mesenchymal transition via a PDGFRα-dependent mechanism.

NT21MP, a 21-residue peptide derived from the viral macrophage inflammatory protein II, competed effectively with the natural ligand of CXC chemokine receptor 4 (CXCR4), stromal cell-derived factor 1-alpha, to induce apoptosis and inhibit growth in breast cancer. Its role in tumor epithelial-to-mesenchymal transition (EMT) regulation remains unknown. In this study, we evaluated the reversal of EMT upon NT21MP treatment and examined its role in the inhibition of EMT in breast cancer. The parental cells of breast cancer (SKBR-3 and MCF-7) and paclitaxel-resistant (SKBR-3 PR and MCF-7 PR) cells were studied in vitro and in combined immunodeficient mice. The mice injected with SKBR-3 PR cells were treated with NT21MP through the tail vein or intraperitoneally with paclitaxel or saline. Sections from tumors were evaluated for tumor weight and EMT markers based on Western blot. In vitro, the effects of NT21MP, CXCR4 and PDGFRα on tumor EMT were assessed by relative quantitative real-time reverse transcription-polymerase chain reaction, western blot and biological activity in breast cancer cell lines expressing high or low levels of CXCR4. Our results illustrated that NT21MP could reverse the phenotype of EMT in paclitaxel-resistant cells. Furthermore, we found that NT21MP governed PR-mediated EMT partly due to controlling platelet-derived growth factors A and B (PDGFA and PDGFB) and their receptor (PDGFRα). More importantly, NT21MP down-regulated AKT and ERK1/2 activity, which were activated by PDGFRα, and eventually reversed the EMT. Together, these results indicated that CXCR4 overexpression drives acquired paclitaxel resistance, partly by activating the PDGFA and PDGFB/PDGFRα autocrine signaling loops that activate AKT and ERK1/2. Inhibition of the oncogenic EMT process by targeting CXCR4/PDGFRα-mediated pathways using NT21MP may provide a novel therapeutic approach towards breast cancer.