A Novel Signature Based on m6A Regulator-Mediated Genes Along Glycolytic Pathway Predicts Prognosis and Immunotherapy Responses of Gastric Cancer Patients.

N6-methyladenosine (m6A) modification is involved in many aspects of gastric cancer (GC). Moreover, m6A and glycolysis-related genes (GRGs) play important roles in immunotherapeutic and prognostic implication of GC. However, GRGs involved in m6A regulation have never been analyzed comprehensively in GC. Herein, the study aims to identify and validate a novel signature based on m6A-related GRGs in GC patients. Therefore, a m6A-related GRGs signature is established, which can predict the survival of patients with GC and remain an independent prognostic factor in multivariate analyses. Clinical significance of the model is well validated in internal cohort and independent validation cohort. In addition, the expression levels of risk model-related GRGs in clinical samples are validated. Consistent with the database results, all model genes are up-regulated in expression except DCN. After regrouping the patients based on this risk model, the study can effectively distinguish between them in respect to immune-cell infiltration microenvironment and immunotherapeutic response. Additionally, candidate drugs targeting risk model-related GRGs are confirmed. Finally, a nomogram combining risk scores and clinical parameters is created, and calibration plots show that the nomogram can accurately predict survival. This risk model can serve as a reliable assessment tool for predicting prognosis and immunotherapeutic responses in GC patients.

Development of a sensitive droplet digital PCR according to the HPV infection specificity in Chinese population.

HPV16 and 18 are positively correlated with cervical carcinogenesis. However, HPV prevalence tends to vary according to region, nationality, and environment. The most prevalent high-risk (HR) HPV genotypes are HPV16, 52, 58, 56, 18, 33, and 45), while the low-risk (LR) genotypes are HPV6 and 11 in the Chinese population. Importantly, undetectable low-copy HPV DNA could be an important indicator of integration into the human genome and may be a precursor to cancer progression. The HPV viral load changes dramatically, either increasing or decreasing rapidly during carcinogenesis, and traditional quantitative real-time PCR (qPCR) cannot accurately capture this subtle change. Therefore, in this study, a reliable droplet digital PCR (ddPCR) method was developed to simultaneously detect and quantify HPV genotypes. The ddPCR quantitative results showed high accuracy, sensitivity, and specificity compared to qPCR results employing the same clinical specimens and supplemented the ddPCR assay for HPV52/56/58/6 genotypes according to the infection specificity of the Chinese population. In summary, this procedure is valuable for quantifying HPV DNA, especially under conditions of low template copy number in cervical intraepithelial neoplasia (CIN) and/or cervical cancer. Additionally, this method can dynamically observe the prognosis and outcome of HPV infection and thus be used as an effective means for real-time monitoring of tumor load.

PHKG2 regulates RSL3-induced ferroptosis in Helicobacter pylori related gastric cancer.

Ferroptosis is a newly discovered form of regulatory cell death induced by iron-dependent lipid peroxidation. Infection with Helicobacter pylori (H. pylori) is regarded as a high-risk factor for the development of gastric cancer (GC) and is associated with an increase in the levels of reactive oxygen species with activation of oncogenic signaling pathways. However, whether GC arising in the context of infection with H. pylori is correlated with ferroptosis is still unknown. In this study, we demonstrate that H. pylori infection increased the sensitivity of GC cells to RSL3 (RAS-selective lethal3)-induced ferroptosis. The molecular subtypes mediated by ferroptosis-related genes are associated with tumor microenvironment (TME) cell infiltration and patient survival. Importantly, we identified that the expression of phosphorylase kinase G2 (PHKG2) was remarkably correlated with H. pylori infection, metabolic biological processes, patient survival and therapy response. We further found the mechanism of H. pylori-induced cell sensitivity to ferroptosis, which involves PHKG2 regulation of the lipoxygenase enzyme Arachidonate 5-Lipoxygenase (ALOX5). In conclusion, PHKG2 facilitates RSL3-induced ferroptosis in H. pylori-positive GC cells by promoting ALOX5 expression. These findings may contribute to a better understanding of the unique pathogenesis of H. pylori-induced GC and allow for maximum efficacy of genetic, cellular, and immune therapies for controlling ferroptosis in diverse contexts.

Functions and modulation of PKM2 activity by human papillomavirus E7 oncoprotein (Review).

Most tumor cells still exhibit active glucose uptake and glycolysis under aerobic conditions, a phenomenon known as the Warburg effect or aerobic glycolysis. Pyruvate kinase, one of the key enzymes in the cell glycolysis pathway, can promote the conversion of glucose to pyruvate and produce energy. Pyruvate kinase M2 (PKM2), a competitive PK subtype, is an important regulator of the aerobic glycolysis pathway in tumor cells and plays a direct role in gene expression and cell cycle regulation. Human papillomavirus (HPV) persistence is the main risk factor for cervical cancer. In recent years, it has been discovered that HPV plays an important role in malignant anal tumors and oral cancer. HPV oncoprotein E7 can promote the Warburg effect and produce a large amount of ATP, which may meet the energy requirements of cancer cell division. There appears to be a regulatory relationship between HPV E7 and PKM2, but the specific mechanism is mostly unknown. The present review article discusses the role of HPV E7 in transcriptional regulation, enzyme activity regulation, protein kinase activity regulation, post-translational modification and the immune microenvironment of PKM2 in the occurrence and development of cervical cancer.

Association and mechanism of garlic consumption with gastrointestinal cancer risk: A systematic review and meta-analysis.

Gastrointestinal cancer is one of the most commonly diagnosed cancer type worldwide, with millions of cases per year. The aim of this review was to investigate the relationship between garlic intake and the risk reduction of gastrointestinal cancer. We performed saturated data mining on various public domain databases, including PubMed (https://pubmed.ncbi.nlm.nih.gov/), Embase (https://www.embase.com/landing?status=grey), and Cochrane Library (https://www.cochranelibrary.com/), with key terms including: 'garlic', 'allium', 'stomach', 'gastric', 'colon', 'neoplasms', 'cancer' and 'tumor'. Furthermore, we identified additional references through expert manual curation. Finally, a meta-analysis was conducted to determine whether garlic intake reduces the risk of gastric and/or colorectal cancer. The association between garlic intake and reduction in the risk of gastric cancer [odds ratio (OR)=0.65, 95% confidence interval (CI)=0.49-0.87, P<0.001] were clear. Nine studies on garlic intake and colorectal cancer showed that garlic reduced cancer risk with a statistical significance (OR=0.75, 95% CI=0.65-0.87, P<0.001). We summarized that four main organic sulfides in garlic, diallyl disulfide (DADS), diallyl trisulfide (DATS), S-allylmercaptocysteine (SAMC) and allicin, may contribute to the regulation of tumor cell apoptosis, migration and the cell cycle. We identified the association between garlic intake and reduced risk of gastric and colorectal cancers and hypothesized that the active ingredients in garlic may act on multiple pathways to reduce the risk of gastrointestinal tumors according to published papers. Importantly, the potential tumor-preventing effect of these garlic ingredients warrants further investigation in regards to the specific mechanism of the underlying antitumor activities.

WDHD1 facilitates G1 checkpoint abrogation in HPV E7 expressing cells by modulating GCN5.

BACKGROUND: Genomic instability is a hallmark of cancer. The G1 checkpoint allows cells to repair damaged DNA that may lead to genomic instability. The high-risk human papillomavirus (HPV) E7 gene can abrogate the G1 checkpoint, yet the mechanism is still not fully understood. Our recent study showed that WDHD1 (WD repeat and high mobility group [HMG]-box DNA-binding protein 1) plays a role in regulating G1 checkpoint of E7 expressing cells. In this study, we explored the mechanism by which WDHD1 regulates G1 checkpoint in HPV E7 expressing cells. METHODS: NIKS and RPE1 derived cell lines were used. Real-time PCR, Rescue experiment, FACS and BrdU labeling experiments were performed to examine role of GCN5 in G1 checkpoint abrogation in HPV-16 E7 expressing cells. RESULTS: In this study, we observed that WDHD1 facilitates G1 checkpoint abrogation by modulating GCN5 in HPV E7 expressing cells. Notably, depletion of WDHD1 caused G1 arrest while overexpression of GCN5 rescued the inhibitory effects of WDHD1 knockdown on G1/S progression. Furthermore, siWDHD1 significantly decreased cell cycle proliferation and DNA synthesis that was correlated with Akt phosphorylation (p-Akt), which was reversed by GCN5 overexpression in HPV E7 expressing cells. CONCLUSIONS: In summary, our data identified a WDHD1/GCN5/Akt pathway leading to the abrogation of G1 checkpoint in the presence of damaged DNA, which may cause genomic instability and eventually HPV induced tumorigenesis.

Patients With LR-HPV Infection Have a Distinct Vaginal Microbiota in Comparison With Healthy Controls.

Condyloma acuminatum (CA) is a benign epithelium hyperplasia mainly caused by human papillomavirus (HPV), which is now the second most common viral sexually transmitted infection (STI) in China. In total, 90% of CA patients are caused by the low-risk HPV 6 and 11. Aside from low-risk HPV infection there are likely other factors within the local microenvironment that contribute to CA and there has been related research before. In this study, 62 vaginal specimens were analyzed using 16S rRNA gene sequencing. The diversity of the vaginal microbiota was higher and the composition was different with LR-HPV infection. While the relative abundance of dominant Firmicutes was lower, Actinobacteria, Proteobacteria, and Fusobacteria phyla were significantly higher; at the genus level Gardnerella, Bifidobacterium, Sneathia, Hydrogenophilus, Burkholderia, and Atopobium were higher. This study firstly confirmed a more accurate and comprehensive understanding of the relationship between low-risk HPV infection and vaginal microbiota, in order to provide a theoretical basis for further research on the occurrence and development of CA.

Development of a loop-mediated isothermal amplification method for rapid detection of streptococcal pyrogenic exotoxin B.

We developed a visual loop-mediated isothermal amplification (LAMP) technique to detect the streptococcal pyrogenic exotoxin B (speB) gene. Fifteen strains (from American Type Culture Collection or clinical isolates) were used to determine the specificity and sensitivity of the LAMP assay. Clinical samples were collected from 132 patients with suspected Streptococcus pyogenes (S. pyogenes) infection to verify the feasibility of the LAMP assay for detection of the speB gene. By using a set of five primers (a pair of outer primers, a pair of inner primers and one loop primer) targeting the speB gene, the amplification reaction was rapidly performed in a regular water bath under isothermal conditions at 63 °C for approximately 60 min. Only the two S. pyogenes strains showed positive results which were easily observed with the naked eye, and the other strains showed negative results. The detection limit of the LAMP assay was 0.01 ng/µl of template, showing higher sensitivity than conventional PCR (with a detection limit of 1.0 ng/µl). The detection rate of the speB gene in clinical samples was 71.21% and was consistent with the PCR results. The rapid detection of the speB gene by the LAMP assay is highly specific and sensitive, is simple to perform and cost-effective, and is expected to be a new reliable method for the rapid diagnosis of S. pyogenes infection, that is particularly suitable for rural or community hospitals in developing countries.

Antitumor effect of a polysaccharide isolated from Phellinus pullus as an immunostimulant.

The antitumor function of fungal polysaccharides is a popular area of interest in the research field due to their high efficiency and low side effects. The main mechanism of fungal polysaccharides is immune enhancement. The polysaccharose (APS-3) was extracted from the fruit body of Phellinus pullus. The proliferation inhibition to mouse sarcoma 180 (S180) tumor cells was studied by the MTT method. Mice models of transplanted S180 tumor were established and treated with APS-3 to verify the antitumor activity in vivo. Natural killer (NK) and lymphokine-activated killer (LAK) cytotoxicities of the mice were evaluated by the lactate dehydrogenase method. APS-3 can significantly inhibit the proliferation of the S180 cells. Cells could be completely inhibited by 1.6 mg/ml APS-3 after 24 h treatment. After 18 days of treatment, the antitumor rate of the high-dose group was 85.47%. Histopathology detection showed that for the APS-3-treated mice, the tumor cells dissolved, and exhibited a large range of structureless necrotic areas. NK and LAK cytotoxicities of the APS-3 treated mice increased by 61.85 and 56.16%, respectively, compared with the normal control mice. APS-3 can be used as an antitumor agent by way of immune enhancement.

Activation of the intrinsic apoptosis pathway contributes to the induction of apoptosis in hepatocellular carcinoma cells by valproic acid.

The level of histone deacetylation is closely associated with the genesis and development of tumors, but the antitumor effect and mechanism of the class I histone deacetylase inhibitor (HDACI) valproate acid sodium (VPA) on hepatocellular carcinoma cells has not been clearly demonstrated. In the present study, the antitumor effect and mechanism of VPA were measured in vitro. Firstly, it was found that, as an HDAC inhibitor, VPA could inhibit HDAC activity and HDAC1 gene expression in hepatocellular carcinoma cells and, as a result, an inhibition of cell proliferation was detected by MTT assay. Subsequently, the cell cycle and cell apoptosis profiles were analyzed using flow cytometry (FCM). The expression of the mRNA and protein of cyclins A, D1 and E and P21Waf/cip1 was measured by reverse transcription-polymerase chain reaction and FCM analysis to determine the molecular mechanism of VPA-induced cell cycle arrest. The activity and mRNA and protein expression of caspases 3, 8 and 9 were detected to determine the apoptotic pathway. Caspase expression was blocked by caspase inhibitors in order to observe whether the intrinsic or extrinsic pathway contributed to HepG2 cell apoptosis. The results revealed that the mRNA and protein expression of cyclins A and D1 was downregulated while the expression of P21Waf/cip1 was upregulated by VPA. The expression of cyclin E was only slightly affected by VPA. The mRNA and protein expression and activity of caspases 3 and 9 were upregulated by VPA. By contrast, inhibitors of caspases 3 and 9 could reverse cell apoptosis and there was no notable change in caspase 8 expression in any of these experiments. The intrinsic apoptosis pathway, but not the death receptor pathway, contributed to the induction of apoptosis in hepatocellular carcinoma cells. Furthermore, VPA could inhibit the proliferation of hepatocellular carcinoma cells by inducing G1 phase arrest and cell apoptosis. These effects were attributed to the change in the caspase level.