Body mass index and γ-glutamyl transferase expression in normal and cancerous breast tissue

Assembly fluorescent probe-based detection of gamma-glutamyl transferase activity in tumor

Detection of γ-glutamyltransferase (GGT) activity in cancer cells is crucial for understanding tumor progression and metabolic dysregulation. However, the accurate detection of GGT remains challenging due to its complex intracellular distribution and interactions with other enzymes. This study introduces a novel hemicyanine-based sensor, named GP, designed for the sensitive and real-time detection of GGT in tumor cells. By leveraging the unique optical properties of hemicyanines in the near-infrared spectrum, the GP sensor enables deeper tissue penetration and minimizes background interference, which is essential for tumor imaging. The sensor incorporates a GGT-specific recognition sequence that selectively binds to GGT, facilitating precise monitoring of its enzymatic activity through fluorescence signals generated by intramolecular charge transfer (ICT). Our results show that the GP probe exhibits high selectivity for GGT, distinguishing it from other biological molecules. Evaluation under tumor-relevant conditions confirms the probe's robustness for both research and clinical applications. In cancer cell models, GP successfully detects increased GGT activity, suggesting its potential for non-invasive monitoring of tumor dynamics. Overall, this study demonstrates GP as a promising tool for the accurate detection of GGT activity, with significant implications for understanding cancer-related metabolic changes and tumor biology.

Deletion of a novel upstream promoter of p53 impairs cold tolerance capacity in zebrafish

P53 is a tumor suppressor that plays a crucial role in stress responses. We previously identified a novel upstream p53 promoter in cold acclimated zebrafish cells, however the functional significance of this upstream promoter under cold stress in zebrafish remains unclear. We generated novel p53 promoter-/- zebrafish using CRISPR/Cas9 and characterized their responses to cold stress. While novel p53 promoter-/- zebrafish exhibited normal development, growth, and locomotion at 28 °C, they showed enhanced locomotor capacity at 18 °C and reduced cold tolerance capacity at 8 °C. RNA-seq revealed the expression of genes related to oxidative stress was downregulated at 8 °C in the gill of novel p53 promoter-/- zebrafish, compared with WT zebrafish. Further experiments confirmed that the ROS levels increased, and the expression of SOD and GSH-PX reduced under cold stress in novel p53 promoter-/- zebrafish, compared with WT zebrafish. The novel p53 promoter plays a critical role in maintaining antioxidant defense and low-temperature tolerance in zebrafish. Our findings provide new theoretical insights into the environmental adaptation mechanisms of fish and offer experimental evidence for the regulatory role of the p53 gene in response to low-temperature stress.

Expression Status and Prognostic Significance of Gamma-Glutamyl Transpeptidase Family Genes in Hepatocellular Carcinoma

PURPOSE

Gamma-glutamyl transpeptidase (GGT) family genes play crucial roles in the formation and progression of several solid tumors. However, the expression patterns and the prognostic significance of GGT members in hepatocellular carcinoma (HCC) remain unknown. This study was designed to determine the expression profiles of GGT family members in HCC and validate the prognostic value of serum GGT protein in patients with HCC.

METHOD

We comprehensively searched public resources based on the LIHC dataset to determine the expression patterns, prognostic significance, DNA methylation status, immune infiltration, and biological pathways of GGT family genes in HCC. Subsequently, we validated the prognostic value of serum GGT protein in 85 patients with early-stage HCC subjected to curative hepatectomy from the Renmin Hospital of Wuhan University.

RESULTS

Except for GGT1, other GGT family members (GGT5, GGT6, and GGT7) were found to be differentially expressed in primary HCC samples (N = 371) and normal control tissues (N = 50). Furthermore, a positive relationship was not only observed between GGT1 and GGT5 (Spearman coefficient: 0.24, P = 5.143 × 10-6) but also between GGT5 and GGT6 (Spearman coefficient: 0.38, P = 1.24 × 10-13). The expression of GGT1, GGT5, and GGT7 was correlated with overall survival (OS), and GGT7 was associated with disease-free survival (DFS) in patients with HCC. Negative associations between DNA methylation and expression of mRNA were observed for GGT1 (Spearman coefficient: -0.38, P = 6.24e-14), GGT6 (Spearman coefficient: -0.29, P = 1.23e-8), and GGT7 (Spearman coefficient: -0.34, P=6.7e-11). GGT family genes were well correlated with the infiltration levels of immune cells in HCC, especially CD4+ T cells, macrophages, and dendritic cells. Finally, when validated with clinical data from the Renmin cohort, a high expression of serum GGT protein was identified as a strong prognostic element of unfavorable OS (HR = 3.114, P = 0.025), but not of DFS (HR = 1.198, P = 0.05) in patients with HCC subjected to curative hepatectomy.

CONCLUSION

To our knowledge, this is the first comprehensive analysis of the expression patterns and clinical value of GGT family genes in patients with HCC. Our study laid the foundation for the clinical application of the GGT protein in the survival assessment of patients with HCC.