Glutaminase potentiates the glycolysis in esophageal squamous cell carcinoma by interacting with PDK1

Increasing evidence has demonstrated that glutaminase (GLS) as a key mitochondrial enzyme plays a pivotal role in glutaminolysis, which widely participates in glutamine metabolism serving as main energy sources and building blocks for tumor growth. However, the roles and molecular mechanisms of GLS in esophageal squamous cell carcinoma (ESCC) remains unknown. Here, we found that GLS was highly expressed in ESCC tissues and cells. GLS inhibitor CB-839 significantly suppressed cell proliferation, colony formation, migration and invasion of ESCC cells, whereas GLS overexpression displayed the opposite effects. In addition, CB-839 markedly suppressed glucose consumption and lactate production, coupled with the downregulation of glycolysis-related proteins HK2, PFKM, PKM2 and LDHA, whereas GLS overexpression exhibited the adverse results. In vivo animal experiment revealed that CB-839 dramatically suppressed tumor growth, whereas GLS overexpression promoted tumor growth in ESCC cells xenografted nude mice. Mechanistically, GLS was localized in mitochondria of ESCC cells, which interacted with PDK1 protein. CB-839 attenuated the interaction of GLS and PDK1 in ESCC cells by suppressing PDK1 expression, which further evoked the downregulation of p-PDHA1 (s293), however, GLS overexpression markedly enhanced the level of p-PDHA1 (s293). These findings suggest that interaction of GLS with PDK1 accelerates the glycolysis of ESCC cells by inactivating PDH enzyme, and thus targeting GLS may be a novel therapeutic approach for ESCC patients.

SIRT2-mediated deacetylation of ACLY promotes the progression of oesophageal squamous cell carcinoma

ATP citrate lyase (ACLY), as a key enzyme in lipid metabolism, plays an important role in energy metabolism and lipid biosynthesis of a variety of tumours. Many studies have shown that ACLY is highly expressed in various tumours, and its pharmacological or gene inhibition significantly inhibits tumour growth and progression. However, the roles of ACLY in oesophageal squamous cell carcinoma (ESCC) remain unclear. Here, our data showed that ACLY inhibitor significantly attenuated cell proliferation, migration, invasion and lipid synthesis in different ESCC cell lines, whereas the proliferation, migration, invasion and lipid synthesis of ESCC cells were enhanced after ACLY overexpression. Furthermore, ACLY inhibitor dramatically suppressed tumour growth and lipid metabolism in ESCC cells xenografted tumour model, whereas ACLY overexpression displayed the opposite effect. Mechanistically, ACLY protein harboured acetylated modification and interacted with SIRT2 protein in ESCC cells. The SIRT2 inhibitor AGK2 significantly increased the acetylation level of ACLY protein and inhibited the proliferation and migration of ESCC cells, while overexpression of ACLY partially reversed the inhibitory effect of AGK2 on ESCC cells. Overall, these results suggest that targeting the SIRT2/ACLY signalling axis may be a potential therapeutic strategy for ESCC patients.

[Correlation analysis between Pirani score and talo-navicular angle,calcaneo-cuboid angle and tibio-calcaneall angle of infant clubfoot under ultrasound]

Objective: To explore the evaluation effect of ultrasonography and Pirani score on tarsal deformity, treatment effect and pseudo-correction of congenital clubfoot in infants and young children, and the correlation between the two methods. Methods: This is a retrospective case series study. The clinical data of 26 children (40 feet) with congenital clubfoot who were evaluated by ultrasonography in the Third Affiliated Hospital of Zhengzhou University from January 2020 to January 2023 were retrospectively collected. There were 16 males and 10 females. The age at the first ultrasound examination was (M(IQR)) 9.0 (18.0) days (range: 1 to 46 days). All patients were treated with Ponseti method by the same physician. The Pirani scores before and after treatment and at the last examination, and the talonavicular angle, calcaneocuboid angle and tibiocalcaneal angle measured by ultrasound were collected, and the treatment and follow-up were recorded. Paired sample t test, repeated measures analysis of variance or Kruskal-Wallis test were used for data comparison, and Spearman correlation analysis was used for correlation analysis. The receiver operating characteristic curve was used to calculate the efficacy of ultrasound in evaluating different Pirani scores. Results: The number of plaster fixation in 26 children was 4.0 (1.0) times (range: 2 to 8 times). The medial talonavicular angle and posterior tibiocalcaneal angle were significantly improved after treatment and at the last follow-up compared with those before treatment, and the differences were statistically significant (all P<0.01). There was no difference in lateral calcaneocuboid angle before and after treatment and at the last follow-up (F=1.971, P>0.05). Pseudo-correction occurred in 2 cases (2 feet) during the treatment, with an incidence of 5%. Correlation analysis showed that there was a moderate positive correlation between talonavicular angle and Pirani midfoot score (r=0.480, P<0.01). There was no correlation between calcaneocuboid angle and Pirani midfoot score (r=0.114, P=0.105). There was a moderate negative correlation between tibial heel angle and Pirani hindfoot score (r=-0.566, P<0.01). The cut-off point of Pirani midfoot score of 1.5 was 38.78°, the sensitivity was 0.90, the specificity was 0.56, and the area under the curve was 0.75. The cut-off value of angle was 27.51 °, the sensitivity was 0.16, the specificity was 0.92, and the area under the curve was 0.44.The cut-off points of Pirani midfoot score of 3.0 were 45.08°and 9.96°, the sensitivity was 0.94 and 0.91, the specificity was 0.37 and 0.42, and the area under the curve was 0.59 and 0.62, respectively. The cut-off values of Pirani hindfoot score of 2.0 and 3.0 were 167.46° and 160.15°, respectively. The sensitivity was 0.75 and 0.67, the specificity was 0.81 and 0.83, and the area under the curve was 0.78 and 0.71, respectively. Conclusion: Ultrasound can complement with Pirani score, visually and dynamically observe the morphology and position changes of talonavicular joint, calcaneocuboid joint and tibiotalocalcaneal joint, monitor the recovery and pseudo-correction of tarsal bones, and better evaluate the therapeutic effect.

Bioinformatics analysis and experimental validation of tumorigenic role of PPIA in gastric cancer

Gastric cancer (GC) is a malignant tumor with high incidence rate and mortality. Due to the lack of effective diagnostic indicators, most patients are diagnosed in late stage and have a poor prognosis. An increasing number of studies have proved that Peptidylprolyl isomerase A (PPIA) can play an oncogene role in various cancer types. However, the precise mechanism of PPIA in GC is still unclear. Herein, we analyzed the mRNA levels of PPIA in pan-cancer. The prognostic value of PPIA on GC was also evaluated using multiple databases. Additionally, the relationship between PPIA expression and clinical factors in GC was also examined. We further confirmed that PPIA expression was not affected by genetic alteration and DNA methylation. Moreover, the upstream regulator miRNA and lncRNA of PPIA were identified, which suggested that LINC10232/miRNA-204-5p/PPIA axis might act as a potential biological pathway in GC. Finally, this study revealed that PPIA was negatively correlated with immune checkpoint expression, immune cell biomarkers, and immune cell infiltration in GC.