Opposing biological functions of the cytoplasm and nucleus DAXX modified by SUMO-2/3 in gastric cancer

Tong

et al. 2021

Cell Death Dis

Self Cite

The 5-methylcytosine (m5C) RNA methyltransferase NSUN2 is involved in the regulation of cell proliferation and metastasis formation and is upregulated in multiple cancers. However, the biological significance of NSUN2 in gastric cancer (GC) and the modification of NSUN2 itself have not been fully investigated. Here, we analyzed the expression level of NSUN2 in tissue microarrays containing 403 GC tissues by immunohistochemistry. NSUN2 was upregulated in GC, and that it was a predictor of poor prognosis. NSUN2 promotes the proliferation, migration, and invasion of GC cells in vitro. We also demonstrated that small ubiquitin-like modifier (SUMO)-2/3 interacts directly with NSUN2 by stabilizing it and mediating its nuclear transport. This facilitates the carcinogenic activity of NSUN2. Furthermore, m5C bisulfite sequencing (Bis-seq) in NSUN2-deficient GC cells showed that m5C-methylated genes are involved in multiple cancer-related signaling pathways. PIK3R1 and PCYT1A may be the target genes that participate in GC progression. Our findings revealed a novel mechanism by which NSUN2 functions in GC progression. This may provide new treatment options for GC patients.

Section: Methodsmentioning

confidence: 99%

NSUN2 modified by SUMO-2/3 promotes gastric cancer progression and regulates mRNA m5C methylation

Tong

et al. 2021

Cell Death Dis

Self Cite

“…Total proteins were harvested, and western blots were performed as described previously (23). Briefly, proteins were separated using 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transferred onto polyvinylidene difluoride membranes.…”

Section: Western Blottingmentioning

confidence: 99%

“…The tissue microarray (TMA) was constructed and immunohistochemistry (IHC) performed as described previously (23). Briefly, TMA slides were dewaxed in xylene, incubated in a 0.5% hydrogen peroxide bath for 10 min, blocked in sheep serum for 30 min, and then incubated with a US31 polyclonal rabbit antibody (diluted 1:500), or CD4, CD8, CD66b, and CD163 polyclonal rabbit antibodies (diluted 1:1000) at 24°C for 2 h. After incubation with secondary antibodies at 24°C, and staining with 3,3′-diaminobenzidine (Dako) and counterstaining with hematoxylin, the TMA slides were analyzed using an Easyscan6 digital slice scanner (MOTIC Medical Diagnostic Systems).…”

Section: Tissue Microarray and Immunohistochemistrymentioning

confidence: 99%

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The Human Cytomegalovirus US31 Gene Predicts Favorable Survival and Regulates the Tumor Microenvironment in Gastric Cancer

et al. 2021

Front. Oncol.

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Human cytomegalovirus (HCMV) is an oncogenic virus associated with tumorigenesis. Our previous study revealed that the HCMV US31 gene interacted with NF-κB2 and mediated inflammation through macrophages. However, there are few reports on the role of US31 in gastric cancer (GC). The aim of this study was to investigate the expression of the US31 gene in GC tissue and assess its role in the occurrence and development of GC. US31 expression in 573 cancer tissues was analyzed using immunohistochemistry. Results showed that US31 was significantly associated with tumor size (P = 0.005) and distant metastasis (P < 0.001). Higher US31 expression indicated better overall survival in GC patients. Overexpression of US31 significantly inhibited the proliferation, migration, and invasion of GC cells in vitro (P < 0.05). Furthermore, expression levels of CD4, CD66b, and CD166 were positively correlated with US31, suggesting that it was involved in regulating the tumor immune microenvironment of GC. RNA sequencing, along with quantitative real-time polymerase chain reaction, confirmed that the expression of US31 promoted immune activation and secretion of inflammatory cytokines. Overall, US31 inhibited the malignant phenotype and regulated tumor immune cell infiltration in GC; these results suggest that US31 could be a potential prognostic factor for GC and may open the door for a new immunotherapy strategy.

“…Cell type and distribution were determined by H&E staining and immunohistochemical staining. The specific experimental steps refer to the previous literature of our team ( 28 ). Primary and secondary antibodies are listed in Table S2 .…”

Section: Methodsmentioning

confidence: 99%

Three-Dimensional Ex Vivo Culture for Drug Responses of Patient-Derived Gastric Cancer Tissue

et al. 2021

Front. Oncol.

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Gastric cancer (GC) is one of the most common malignancies with high mortality and substantial morbidity. Although the traditional treatment strategies for GC revolve around surgery, radiotherapy, and chemotherapy, none have been able to optimally treat most affected patients. To improve clinical outcomes and overcome potential GC resistance, we established a three-dimensional (3D) culturing platform that accurately predicts drug responses in a time- and cost-effective manner. We collected tumor tissues from patients following surgeries and cultured them for 3 days using our protocol. We first evaluated cell proliferation, viability, and apoptosis using the following markers: Ki67 and cleaved caspase 3 (Cas3). We demonstrated that cell viability was maintained for 72 h in culture and that the tumor microenvironments and vascular integrities of the tissues were intact throughout the culture period. We then administered chemotherapeutics to assess drug responses and found differential sensitivity across different patient-derived tissues, enabling us to determine individualized medication plans. Overall, our study validated this rapid, cost-effective, scalable, and reproducible protocol for GC tissue culture that can be employed for drug response assessments. Our 3D culture platform paves a new way for personalized medication in GC and other tumors and can greatly impact future oncological research.