Data on the effects of eIF6 downmodulation on the proportions of innate and adaptive immune system cell subpopulations and on thymocyte maturation

eIF6 is potential diagnostic and prognostic biomarker that associated with 18F-FDG PET/CT features and immune signatures in esophageal carcinoma

Background

Although eukaryotic initiation factor 6 (eIF6) is a novel therapeutic target, data on its importance in the development of esophageal carcinoma (ESCA) remains limited. This study evaluated the correlation between eIF6 expression and metabolic analysis using fluorine-18 fluorodeoxyglucose (¹⁸F-FDG) -Positron emission tomography (PET) and immune gene signatures in ESCA.

Methods

This study employed The Cancer Genome Atlas (TCGA) to analyze the expression and prognostic value of eIF6, as well as its relationship with the immune gene signatures in ESCA patients. The qRT-PCR and Western blot analyses were used to profile the expression of eIF6 in ESCA tissues and different ESCA cell lines. The expression of tumor eIF6 and glucose transporter 1 (GLUT1) was examined using immunohistochemical tools in fifty-two ESCA patients undergoing routine ¹⁸F-FDG PET/CT before surgery. In addition, the cellular responses to eIF6 knockdown in human ESCA cells were assessed via the MTS, EdU, flow cytometry and wound healing assays.

Results

Our data demonstrated that compared with the normal esophageal tissues, eIF6 expression was upregulated in ESCA tumor tissues and showed a high diagnostic value with an area under curve of 0.825 for predicting ESCA. High eIF6 expression was significantly correlated with shorter overall survival of patients with esophagus adenocarcinoma (p = 0.038), but not in squamous cell carcinoma of the esophagus (p = 0.078). In addition, tumor eIF6 was significantly associated with ¹⁸F-FDG PET/CT parameters: maximal and mean standardized uptake values (SUVmax and SUVmean) and total lesion glycolysis (TLG) (rho = 0.458, 0.460, and 0.300, respectively, p < 0.01) as well as GLUT1 expression (rho = 0.453, p < 0.001). A SUVmax cutoff of 18.2 led to prediction of tumor eIF6 expression with an accuracy of 0.755. Functional analysis studies demonstrated that knockdown of eIF6 inhibited ESCA cell growth and migration, and fueled cell apoptosis. Moreover, the Bulk RNA gene analysis revealed a significant inverse association between eIF6 and the tumor-infiltrating immune cells (macrophages, T cells, or Th1 cells) and immunomodulators in the ESCA microenvironment.

Conclusion

Our study suggested that eIF6 might serve as a potential prognostic biomarker associated with metabolic variability and immune gene signatures in ESCA tumor microenvironment.

Ribosome profiling unveils translational regulation of metabolic enzymes in primary CD4+ Th1 cells

The transition from a naïve to an effector T cell is an essential event that requires metabolic reprogramming. We have recently demonstrated that the rapid metabolic changes that occur following stimulation of naïve T cells require the translation of preexisting mRNAs. Here, we provide evidence that translation regulates the metabolic asset of effector T cells. By performing ribosome profiling in human CD4⁺ Th1 cells, we show that the metabolism of glucose, fatty acids and pentose phosphates is regulated at the translational level. In Th1 cells, each pathway has at least one enzyme regulated at the translational level and selected enzymes have high translational efficiencies. mRNA expression does not predict protein expression. For instance, PKM2 mRNA is equally present in naïve T and Th1 cells, but the protein is abundant only in Th1. 5'-untranslated regions (UTRs) may partly account for this regulation. Overall we suggest that immunometabolism is controlled by translation.