Knockdown of RNF183 suppressed proliferation of lung adenocarcinoma cells via inactivating the STAT3 signaling pathway

The ZNF263/CPT1B axis regulates fatty acid β-oxidation to affect cisplatin resistance in lung adenocarcinoma

Cisplatin is widely used as a conventional chemotherapy drug for lung adenocarcinoma (LUAD) patients. However, the chemical resistance greatly limits its therapeutic potential. The study aimed to uncover the specific role and new mechanisms of CPT1B in the cisplatin resistance of LUAD. Bioinformatics analysis was utilized to analyze the expression level and enriched pathway of CPT1B in LUAD. The expression of CPT1B in LUAD cells was determined by utilizing quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot (WB). The cisplatin resistance in LUAD was measured with IC50 values obtained from the CCK-8 assay. We used the corresponding reagent kit and WB analysis to determine the levels of triglycerides, cholesterol, phospholipids, fatty acid β-oxidation (FAO) rate, and expression of lipid metabolism-related proteins. Finally, the regulation relationship between CPT1B and ZNF263 was confirmed through bioinformatics analysis, dual-luciferase, and chromatin immunoprecipitation assays. The present investigation revealed that CPT1B was upregulated in LUAD, participating in fatty acid metabolism pathways. In vitro studies have shown that upregulation of CPT1B promoted cisplatin resistance in LUAD cells. This promotion effect induced by the high expression of CPT1B on cisplatin resistance in LUAD was weakened after the addition of the FAO inhibitor Etomoxir. Mechanistically, ZNF263 was capable of binding to the promoter of CPT1B to activate its transcription, thereby enhancing FAO and promoting cisplatin resistance in LUAD cells. In summary, ZNF263 enhances cisplatin resistance in LUAD cells by upregulating CPT1B expression. This study enriches the molecular mechanisms of LUAD chemotherapy resistance and provides new directions for exploring therapeutic targets for LUAD.

A novel approach to the analysis of Overall Survival (OS) as response with Progression-Free Interval (PFI) as condition based on the RNA-seq expression data in The Cancer Genome Atlas (TCGA)

BACKGROUND

Overall Survival (OS) and Progression-Free Interval (PFI) as survival times have been collected in The Cancer Genome Atlas (TCGA). It is of biomedical interest to consider their dependence in pathway detection and survival prediction. We intend to develop novel methods for integrating PFI as condition based on parametric survival models for identifying pathways associated with OS and predicting OS.

RESULTS

Based on the framework of conditional probability, we developed a family of frailty-based parametric-models for this purpose, with exponential or Weibull distribution as baseline. We also considered two classes of existing methods with PFI as a covariate. We evaluated the performance of three approaches by analyzing RNA-seq expression data from TCGA for lung squamous cell carcinoma and lung adenocarcinoma (LUNG), brain lower grade glioma and glioblastoma multiforme (GBMLGG), as well as skin cutaneous melanoma (SKCM). Our focus was on fourteen general cancer-related pathways. The 10-fold cross-validation was employed for the evaluation of predictive accuracy. For LUNG, p53 signaling and cell cycle pathways were detected by all approaches. Furthermore, three approaches with the consideration of PFI demonstrated significantly better predictive performance compared to the approaches without the consideration of PFI. For GBMLGG, ten pathways (e.g., Wnt signaling, JAK-STAT signaling, ECM-receptor interaction, etc.) were detected by all approaches. Furthermore, three approaches with the consideration of PFI demonstrated better predictive performance compared to the approaches without the consideration of PFI. For SKCM, p53 signaling pathway was detected only by our Weibull-baseline-based model. And three approaches with the consideration of PFI demonstrated significantly better predictive performance compared to the approaches without the consideration of PFI.

CONCLUSIONS

Based on our study, it is necessary to incorporate PFI into the survival analysis of OS. Furthermore, PFI is a survival-type time, and improved results can be achieved by our conditional-probability-based approach.

Roles of naïve CD4+ T cells and their differentiated subtypes in lung adenocarcinoma and underlying potential regulatory pathways

BACKGROUND

Naïve CD4+ T cells and their differentiated counterparts play a significant regulatory role in the tumor immune microenvironment, yet their effects on lung adenocarcinoma (LUAD) are not fully understood.

METHODS

We utilized Mendelian randomization to assess the causal association between naïve CD4+ T cells and LUAD. Employing a modified single-sample Gene Set Enrichment Analysis (ssGSEA) algorithm with The Cancer Genome Atlas (TCGA) database, we determined the infiltration levels of naïve CD4+ T cells and their differentiation subtypes and investigated their correlation with clinical characteristics. Potential regulatory pathways of T helper cells were identified through Mantel tests and Kyoto Encyclopedia of Genes and Genomes (KEGG) database enrichment analysis.

RESULTS

Mendelian randomization analysis revealed an inhibitory effect of naïve CD4+ T cells on LUAD (false discovery rate < 0.05), which was corroborated by observational experiments using TCGA database. Specifically, T helper cell type 2 demonstrated a promotive effect on LUAD in terms of overall, disease-free, and progression-free survival (p < 0.05). Moreover, regulatory T cells exhibited a protective effect on LUAD in terms of disease-specific survival (p < 0.01). Concurrently, we explored the overall impact of naïve CD4+ T cell differentiation subtypes on LUAD, revealing upregulation in pathways such as neutrophil degranulation, MAPK family signaling pathways, and platelet activation, signaling, and aggregation.

CONCLUSION

Naïve CD4+ T cells and their differentiated counterparts play essential regulatory roles in the tumor immune microenvironment, demonstrating bidirectionality in their effects.Thus, elucidating the mechanisms and developing novel cell differentiation-inducing agents will benefit anti-cancer therapy.

Advances of E3 ligases in lung cancer

Lung cancer is a leading cause of cancer-related death, and the most common type of lung cancer is non-small cell lung cancer, which accounts for approximately 85 % of lung cancer diagnoses. Recent studies have revealed that ubiquitination acts as a crucial part of the development and progression of lung cancer. The E1-E2-E3 three-enzyme cascade has a core function in ubiquitination, so targeted adjustments of E3 ligases could be used in lung cancer treatment. Hence, we elucidate research advances in lung cancer-related E3 ligases by briefly describing the structure and categorization of E3 ligases. Here, we provide a detailed review of the mechanisms by which lung cancer-related E3 ligases modify substrate proteins and regulate signaling pathways to facilitate or suppress cancer progression. We hope to show a new perspective on targeted precision therapy for lung cancer.

RNF183 Promotes Colon Cancer Cell Stemness through Fatty Acid Oxidation

Colon cancer (COAD) is a prevalent gastrointestinal tumor, composed of a few cancer stem cells (CSCs). High expression of RNF183 drives colorectal cancer metastasis, but its role in COAD cell stemness is still unclear. Bioinformatics analyzed expression and enriched pathway of RNF183 in COAD tissue. IHC analyzed RNF183 protein expression in tumor tissue. CD133 + CD44+ CSCs were sorted by flow cytometry, and RNF183 expression in COAD cells or CSCs was detected by qPCR, western blot and immunofluorescence. CCK-8 assay assessed cell viability, and sphere formation assay tested cell sphere-forming ability. Western blot measured protein expression of stem cell markers. qPCR assayed expression of fatty acid oxidation genes. The ability of fatty acid oxidation was analyzed by detecting fatty acid metabolism. RNF183 was highly expressed in COAD and CD133 + CD44+ CSCs, and was enriched in fatty acid metabolism pathway. RNF183 expression was positively correlated with enzymes involved in fatty acid oxidation. RNF183 could promote COAD stemness and fatty acid oxidation. Rescue experiments showed that Orlistat (a fatty acid oxidation inhibitor) reversed stimulative impact of RNF183 overexpression on COAD stemness. RNF183 promoted COAD stemness by affecting fatty acid oxidation, which may be a new therapeutic target for inhibiting COAD development.