Depressed tumor necrosis factor alpha and interleukin-12p40 production by peripheral blood mononuclear cells of gastric cancer patients: Association with IL-1R-associated kinase-1 protein expression and disease stage

Review on active components and mechanism of natural product polysaccharides against gastric carcinoma

One of the malignant tumors with a high occurrence rate worldwide is gastric carcinoma, which is an epithelial malignant tumor emerging from the stomach. Natural product polysaccharides are a kind of natural macromolecular polymers, which have the functions of regulating immunity, anti-oxidation, anti-fatigue, hypoglycemia, etc. Natural polysaccharides have remarkable effectiveness in preventing the onset, according to studies, and development of gastric cancer at both cellular and animal levels. This paper summarizes the inhibitory mechanisms and therapeutic significance of plant polysaccharides, fungi polysaccharides, and algal polysaccharides in natural product polysaccharides on the occurrence and development of gastric cancer in recent years, providing a theoretical basis for the research, development, and medicinal value of polysaccharides.

N6-methyladenosine-related lncRNAs identified as potential biomarkers for predicting the overall survival of Asian gastric cancer patients

Objective

Gastric cancer (GC) is one of the most prevalent malignant tumors in Asian countries. Studies have proposed that lncRNAs can be used as diagnostic and prognostic indicators of GC due to the high specificity of lncRNAs expression involvement in GC. Recently, N6-methyladenosine (m6A) has also emerged as an important modulator of the expression of lncRNAs in GC. This study aimed at establishing a novel m6A-related lncRNAs prognostic signature that can be used to construct accurate models for predicting the prognosis of GC in the Asian population.

Methods

First, the levels of m6A modification and m6A methyltransferases expression in GC samples were determined using dot blot and western blot analyses. Next, we evaluated the lncRNAs expression profiles and the corresponding clinical data of 88 Asian GC patients retrieved from The Cancer Genome Atlas (TCGA) database. Differential expression of m6A-related lncRNAs between GC and normal tissues was investigated. The relationship between these target lncRNAs and potential immunotherapeutic signatures was also analyzed. Gene set enrichment analysis (GSEA) was performed to identify the malignancy-associated pathways. Univariate Cox regression, LASSO regression, and multivariate Cox regression analyses were performed to establish a novel prognostic m6A-related lncRNAs prognostic signature. Moreover, we constructed a predictive nomogram and determined the expression levels of nine m6A-related lncRNAs in 12 pairs of clinical samples.

Results

We found that m6A methylation levels were significantly increased in GC tumor samples compared to adjacent normal tissues, and the increase was positively correlated with tumor stage. Patients were then divided into two clusters (cluster 1 and cluster 2) based on the differential expression of the m6A-related lncRNAs. Results showed that there was a significant difference in survival probability between the two clusters (p = 0.018). Notably, the low survival rate in cluster 2 may be associated with high expression of immune cells (resting memory CD4⁺ T cells, p = 0.027; regulatory T cells, p = 0.0018; monocytes, p = 0.00095; and resting dendritic cells, p = 0.015), and low expression of immune cells (resting NK cells, p = 0.033; and macrophages M1, p = 0.045). Enrichment analysis indicated that malignancy-associated biological processes were more common in the cluster 2 subgroup. Finally, the risk model comprising of six m6A-related lncRNAs was identified as an independent predictor of prognoses, which could divide patients into high- or low-risk groups. Time-dependent ROC analysis suggested that the risk score could accurately predict the prognosis of GC patients. Patients in the high-risk group had worse outcomes compared to patients in the low-risk group, and the risk score showed a positive correlation with immune cells (resting memory CD4⁺ T cells, R = 0.31, P = 0.038; regulatory T cells, R = 0.42, P = 0.0042; monocytes, R = 0.42, P = 0.0043). However, M1 macrophages (R = -0.37, P = 0.012) and resting NK cells (R = -0.31, P = 0.043) had a negative correlation with risk scores. Furthermore, analysis of clinical samples validated the weak positive correlation between the risk score and tumor stage.

Conclusions

The risk model described here, based on the six m6A-related lncRNAs signature, and may predict the clinical prognoses and immunotherapeutic response in Asian GC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09801-z.

Perturbation of miR-146b and relevant inflammatory elements in esophageal carcinoma patients supports an immune downregulatory mechanism

BACKGROUND

Esophageal Cancer is known as one of the deadliest cancers worldwide with the squamous cell carcinoma (ESCC) being the predominant subtype. There is a growing body of evidence linking the dysregulated microRNA (miRNA) pathway of immune cells to the progression of several tumors. In a previous study, we investigated molecular alterations pertaining to miR-146a and some components of NF-kB signaling pathway and proposed a possible immune downregulatory mechanism in peripheral blood mononuclear cells (PBMCs) of ESCC patients. Here, we further scrutinized other components of this pathway by evaluating PBMC levels of miR-146b, TLR4, IL10, and TNFA.

METHODS

Gene expressions were quantified using RT-qPCR assays. To prevent the vulnerability of results to the expression instability of reference genes, nine additional transcripts were quantified, and stable reference genes for normalizing qPCR data were identified using the NormFinder and the geNorm algorithms. The efficiency-corrected normalized relative quantity values were used to compare gene expressions among study groups.

RESULTS

The PBMC expression of miR-146b and TNFA was downregulated in ESCC patients as compared to healthy subjects. While the level of TLR4 was not different among the study groups, the PBMC level of IL10 was upregulated in ESCC patients. Logistic regression analyses coupled with the ROC curve and cross-validation analysis suggested that PBMC expression may serve as potential candidate biomarker for discriminating ESCC patients from healthy subjects.

CONCLUSION

The present findings, in line with our previous report, propose a particular gene expression pattern in PBMCs of ESCC patients, providing evidence in support of an immune downregulatory mechanism.

The role of protein kinases in pancreatic carcinogenesis

BACKGROUND

Pancreatic cancer is a devastating disease with a very poor prognosis.

METHODS

Protein kinases are aberrantly expressed in pancreatic ductal adenocarcinoma as analyzed by microarray-based expression analysis and have an impact for pancreatic cancer. Many regulatory proteins have an impact on cancer progression similar to the kinases. The list contains several regulators of kinases derived from the cell cycle control or the mitogen-activated protein (MAP)-kinase pathway.

CONCLUSION

Both signalling pathways are essential for tumor progression and pancreatic ductal adenocarcinoma (PDAC) malignancy.