STK4 is a prognostic biomarker correlated with immune infiltrates in clear cell renal cell carcinoma.

BACKGROUND: Mammalian STE20-like kinase 1 (MST1/STK4/KRS2) is a highly conserved serine/threonine kinase and a central member of the Hippo signaling pathway. STK4 has been reported to play important roles in various tumors, but a systematic and comprehensive study of its function in clear cell renal cell carcinoma (ccRCC) has not been conducted. METHODS: In this study, we used immunohistochemistry (IHC), western blot (WB), quantitative real-time PCR (qPCR) experiments, and bioinformatics analysis to comprehensively analyze the expression, prognostic value, and immune infiltration of STK4 in ccRCC. RESULTS: Analysis of the TCGA database showed that the expression level of the STK4 gene in ccRCC patients depended on tumor stage, grade, and distant lymphatic metastasis. This was further confirmed by the results of IHC, WB, and qPCR. In addition, we used the receiver operating characteristic curve (ROC curve) to elucidate the diagnostic value of STK4 in ccRCC patients. According to the findings of the TIMER database, the high expression of STK4 is significantly associated with the survival of kidney cancer (including ccRCC) patients (p < 0.001), suggesting that STK4 is a reliable prognostic predictor. We then used gene set enrichment analysis (GSEA) to explore the mechanisms behind STK4 function in ccRCC. We found that STK4 may play a role in immune regulation interactions. Subsequently, we performed immune infiltration analysis of STK4. The results showed that STK4 may regulate the development of ccRCC by affecting the immune infiltration of NK and pDC cells. CONCLUSIONS: STK4 may be a prognostic marker for ccRCC and may help identify new strategies for treating ccRCC patients.

Prognostic value of sirtuin family members and experimental verification identify SIRT5 as diagnostic biomarkers in clear cell renal cell carcinoma.

Background: The sirtuins (SIRTs) family is a nicotinamide adenine dinucleotide (NAD+) family of dependent deacetylases, which includes SIRT1-7. This family is related to the development and progression of various tumors. However, a comprehensive analysis of the role of SIRTs in clear cell renal cell carcinoma (ccRCC) is still lacking, and there are few reports on the inhibitory role of SIRT5 in ccRCC. Methods: We used immunohistochemical analysis, and several bioinformatic databases to perform an integrated analysis of the expression and prognostic value of SIRT5 and other SIRT family members in ccRCC along with the associated immune cell infiltration. These databases include TIMER, THPA, cell culture, UALCAN, cBioPortal, WebGestalt, Metascape, DiseaseMeth, STRING database, and Cytoscape. Results: The protein expression of SIRT1, 2, 3, 6, and 7 were upregulated in ccRCC for the Human Protein Atlas database, whereas the expression of SIRT4 and SIRT5 was decreased. The expression based on tumor stage, and grade followed a similar trend. Kaplan-Meier analysis showed that high SIRT4 and SIRT5 expression was positively related to better overall survival (OS), whereas SIRT6 and SIRT7 expression was positively related to worse OS. Further, high SIRT3 expression was related to worse relapse-free survival (RFS), whereas high SIRT5 expression was related to better RFS. To explore the mechanism underlying the function of SIRTs in ccRCC, we also used several databases to perform the functional enrichment analysis and explore the relationship between infiltrating immune cells and seven SIRT family members in ccRCC. The results showed that several SIRT family members, and particularly SIRT5, are correlated with the infiltration of some important immune cells. The protein expression of SIRT5 was significantly lower in tumor tissue compared to normal tissue and was negatively related to the age of the patient ccRCC individual tumor stages, and grades. In human ccRCC samples, strong IHC staining expression of SIRT5 was displayed in adjacent normal tissue than in tumor tissues. Conclusion: SIRT5 may be a prognostic marker and a novel strategy for the treatment of ccRCC.

Prognostic value and immune infiltration of the gasdermin family in lung adenocarcinoma.

Background: The GSDM family includes six members, GSDMA, GSDMB, GSDMC, GSDMD, GSDME (DFNA5), and PJVK (Pejvakin, DFNB59), which can induce pyroptosis, thereby regulating the tumorigenesis of various cancers. However, the clinical characteristics and role of the GSDM family in LUAD are not well understood. Methods: In this study, several important bioinformatics databases were used to integrate the analysis of the expression, prognostic value, and immune infiltration of GSDMs in LUAD. These databases include UALCAN, DiseaseMeth, GEPIA, THPA, cBioPortal, TIMER, WebGestalt, STRING database, and Cytoscape. Results: The findings from the UALCAN database revealed that the expression of all six GSDMs based on the tumor stage in LUAD was increased (particularly GSDMD). Our IHC results verified it. Additionally, the DiseaseMeth database showed that the methylation levels of GSDMA, GSDMB, GSDMC, and GSDMD were decreased. The expression of six GSDMs was related to shorter overall survival in patients with LUAD, according to the GEPIA database. The cBioPortal database was further used to explore the alteration rate and correlated genes in LUAD. Subsequently, these genes were subjected to functional enrichment and protein-protein interaction network analyses. We identified that the GSDM family regulate several signaling pathways, including immune-associated signaling pathways. According to tumor-infiltrating immune cell analysis from the TIMER database, GSDM family members are associated with the infiltration of important immune cells and their signature markers. Conclusions: GSDM family may be prognostic markers and novel strategies for the treatment of LUAD.

PI3K/AKT pathway mediates the antidepressant- and anxiolytic-like roles of hydrogen sulfide in streptozotocin-induced diabetic rats via promoting hippocampal neurogenesis.

We have previously demonstrated that hydrogen sulfide (H2S), the third endogenous gasotransmitter, ameliorates the depression- and anxiety-like behaviors in diabetic rats, but the underlying mechanism remains unclear. The present was aimed to investigate whether the hippocampal phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway mediates H2S-ameliorated depression- and anxiety-like behaviors in diabetic rats by improving the hippocampal neurogenesis. The depression-like behaviors were examined by Tail suspension test (TST), the anxiety-like behaviors were examined by Elevated plus maze test (EPM), and the locomotor activity was detected by Open Field Test (OFT). The expressions of doublecortin (DCX), neuron-specific nuclear protein (NeuN), glial fibrillary acidic protein (GFAP), p-AKT, and AKT in the hippocampus were determined by Western blot analysis. Results showed that NaHS, a donor of exogenous H2S, not only activated the hippocampal PI3K/AKT pathway, as evidenced by the increase of phosphorylated AKT, but also favorably reversed streptozotocin (STZ)-disturbed hippocampal neurogenesis, as evidenced by the increases in the expressions of DCX and NeuN as well as the decrease in the expression of GFAP in the hippocampus of STZ-induced diabetic rats. Furthermore, inhibited PI3K/AKT pathway by LY294002 significantly abolished H2S-exerted the improvement of hippocampal neurogenesis and the antidepressant- and anxiolytic-like effects in the STZ-induced diabetic rats. Taken together, these results uncover that the activation of hippocampal PI3K/AKT pathway plays an important role to restore hippocampal neurogenesis and subsequently to mediate the antidepressant- and anxiolytic-like roles of H2S in STZ-induced diabetic rats and enhance our understanding of the robustness of H2S as a therapeutic strategy for treatment of depression in diabetes mellitus.