Decitabine enhances the tumoricidal potential of TRAIL via the epigenetic regulation of death receptor 4 in gastric cancer

Combination therapies and novel delivery systems: a new frontier in overcoming TRAIL resistance in gastric cancer

Gastric cancer (GC) presents a formidable challenge in oncology, mainly due to its inherent resistance to therapies such as tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). This review delineates the multifaceted mechanisms underlying TRAIL resistance in GC, encompassing the deregulation of death receptors (DRs) and decoy receptors (DcRs), aberrant signaling pathways, and the influence of the tumor microenvironment (TME). Innovative strategies such as nanoparticle-based drug delivery systems and oncolytic viral therapies are being explored to counteract these challenges. Nanoparticles enhance TRAIL delivery and efficacy by exploiting the enhanced permeability and retention (EPR) effect, while oncolytic viruses can selectively target cancer cells and stimulate immune responses. Combination therapies, integrating TRAIL with conventional chemotherapeutics like paclitaxel, cisplatin, and 5-fluorouracil, have shown promise in overcoming resistance by modulating apoptotic pathways and downregulating multidrug resistance genes. Additionally, novel agents like cyclopamine, decitabine, and genistein have emerged as effective TRAIL sensitizers by modulating apoptotic pathways and enhancing DR5 expression. Furthermore, the integration of epigenetic modifiers can restore TRAIL sensitivity by demethylating DR4 and DR5 genes. This review emphasizes the need for a comprehensive understanding of the molecular underpinnings of TRAIL resistance and the potential of combination therapies and TRAIL delivery by nanoparticles and oncolytic viruses to enhance treatment outcomes in GC. Future research should focus on elucidating predictive biomarkers and optimizing therapeutic regimens to improve the clinical efficacy of TRAIL-based strategies in GC.

Correlation between inflammatory cytokines and the likelihood of developing multiple types of digestive system cancers: A Mendelian randomization study

OBJECTIVE

Inflammatory cytokines have been linked to digestive system cancers, yet their exact causal connection remains uncertain. Consequently, we conducted a Mendelian randomization (MR) analysis to gauge how inflammatory cytokines are linked to the risk of five prevalent digestive system cancers (DSCs).

METHODS

We collected genetic variation data for 41 inflammatory cytokines from genome-wide association studies (GWAS), and the results data for five common diseases from the Finnish database. Our primary analytical approach involved employing the inverse-variance weighted, residual sum (IVW) method, complemented by the MR-Egger method, the weighted median method, simple mode analysis, and weighted mode analysis as supplementary analytical techniques. Furthermore, we conducted multiple sensitivity analyses.

RESULTS

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), macrophage colony-stimulating factor (M-CSF), and interleukin (IL)-18 showed a negative association with the risk of hepatocellular carcinoma. Conversely, TRAIL was inversely linked to the risk of gastric cancer, while IL-16 exhibited a positive correlation with gastric cancer risk. Stem cell factor (SCF) acted as a protective factor against pancreatic cancer. For colorectal cancer, IL-7, IL-9, IL-13, and vascular endothelial growth factor (VEGF) were identified as risk factors. Notably, our results did not indicate a significant correlation between inflammatory cytokines and the risk of esophageal cancer.

CONCLUSION

Our research unveils potential connections between 41 inflammatory cytokines and the risk of five common DSCs through a MR analysis. These associations offer valuable insights that could aid in the development of diagnostic biomarkers and the identification of novel therapeutic targets for DSCs.

Decitabine enclosed biotin-zein conjugated nanoparticles: synthesis, characterization, in vitro and in vivo evaluation

Aim: This study focuses on biotinylated nanocarriers designed to encapsulate amphiphilic molecules with self-biodegradable properties for enhanced drug delivery.Methods: Biotin-zein conjugated nanoparticles were synthesized and tested in C6 cell lines to evaluate their viability and cellular uptake. Optimization was achieved using a a central composite design. The nanoparticles underwent thermogravimetric analysis, and their pharmacokinetics and biodistribution were also studied.Results: The optimized nanoparticles displayed 96.31% drug encapsulation efficiency, a particle size of 95.29 nm and a zeta potential of -17.7 mV. These nanoparticles showed increased cytotoxicity and improved cellular uptake compared with free drugs. Thermogravimetric analysis revealed that the drug-loaded nanocarriers provided better protection against drug degradation. Pharmacokinetic and biodistribution studies indicated that the formulation had an extended brain residence time, highlighting its effectiveness.Conclusion: The biotin-zein conjugated nanoparticles developed in this study offer a promising nano-vehicle for in vivo biodistribution and pharmacokinetic applications. Their high drug encapsulation efficiency, stability and extended brain residence time suggest they are effective for targeted drug delivery and therapeutic uses.

[Prognostic Value of PCMT1 Expression in Gastric Cancer and Its Regulatory Effect on Spindle Assembly Checkpoints]

Objective

The study was conducted to investigate the expression of protein-L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1) in gastric cancer and its effect on the prognosis, and to analyze its potential mechanism.

Methods

UALCAN, a cancer data analysis platform, was used to conduct online analysis of the expression of PCMT1 in gastric cancer tissues. Through the Database for Annotation, Visualization and Integrated Discovery (DAVID), Gene Ontology (GO) annotation and signaling pathway enrichment by Kyoto Encyclopedia of Genes and Genomes (KEGG) were performed to analyze the possible functions and signaling pathways. A total of 120 patients who underwent radical gastrectomy for gastric cancer between January 2014 and December 2017 in our hospital were enrolled for the study. Immunohistochemical staining was performed to determine the expression of PCMT1 and Ki67 in gastric cancer tissues. Cox regression, Kaplan-Meier curve, and receiver operating characteristic (ROC) curves were used for prognostic analysis of 5-year survival in gastric cancer patients after surgery. Lentivirus was used to construct PCMT1-interfering or PCMT1-overexpressing vectors, which were then used to transfect human gastric cancer cell lines of MGC-803 and HGC-27 cells. The interfering empty vector (sh-NC) group, the interfering PCMT1 vector (sh-PCMT1) group, the overexpressing empty vector (LV-Vec) group, and the overexpressing PCMT1 vector (LV-PCMT1) group were set up. Western blot was performed to determine the protein expression levels of PCMT1, CyclinB1, and CDC20. CCK-8 assay was performed to measure the proliferation of gastric cancer cells. Flow cytometry was performed to determine the cell cycle. MGC-803 cells were injected in four groups of nude mice to construct a subcutaneous xenograft tumor model, with three nude mice in each group. The body mass of the nude mice was measured. The nude mice were sacrificed after 14 days and the tumor volume was monitored. The expression levels of CyclinB1 and CDC20 proteins in the tumor tissues were determined by Western blot assay.

Results

Analysis with UALCAN showed that PCMT1 was highly expressed in gastric cancer tissues. Moreover, elevated expression was found in gastric tumor tissues of different pathological stages and grades and those with lymph node metastasis (P<0.05). GO and KEGG enrichment analyses showed that PCMT1 was mainly involved in the signal regulation of mitosis, spindle assembly checkpoints, and cell cycle. The immunohistochemical results showed that PCMT1 and Ki67 were highly expressed in gastric cancer tissues and that they were positively correlated with each other (P<0.05). Cox multivariate analysis showed that high PCMT1 expression (hazard ratio [HR]=2.921, 95% confidence interval [CI]:1.628-5.239) was one of the independent risk factors affecting the 5-year survival rate of gastric cancer patients after surgery. Kaplan-Meier curve showed that patients with high PCMT1 expression had a lower 5-year survival after surgery (16.7%, HR=4.651, 95% CI: 2.846-7.601) than patients with low PCMT1 expression (70.0%, HR=0.215, 95% CI: 0.132-0.351) did. The ROC curve showed that PCMT1 had an area under the curve (AUC) of 0.764 (95% CI: 0.674-0.854) for predicting 5-year patient survival after surgery. Western blot results showed that lentiviral interference or overexpression of PCMT1 cell lines was successfully constructed. The results of CCK-8 showed that the proliferative ability of MGC-803 and HGC-27 cells was weakened with the downregulation of PCMT1, and the overexpression of PCMT1 promoted cell proliferation (P<0.05). With the interference of PCMT1, the expression of CDC20 protein was decreased, the expression of CyclinB1 protein was increased, and the cell cycle was arrested in the G2/M phase. In contrast, the overexpression of PCMT1 led to the opposite trends (P<0.05). In the sh-PCMT1 group, the tumor volume and mass were decreased and the expression of CDC20 protein was decreased and the expression of CyclinB1 protein was increased in the tumor tissues of the nude mice (P<0.05, compared with those of the sh-NC group. In contrast, the LV-PCMT1 group showed the opposite trends (P<0.05, compared with those of the LV-Vec group).

Conclusion

The high expression of PCMT1 in gastric cancer tissues is associated with poor prognosis in patients and may affect tumor cell malignant proliferation via regulating spindle checkpoints in the process of mitosis.