STK25 enhances hepatocellular carcinoma progression through the STRN/AMPK/ACC1 pathway

The TWK-26 potassium channel governs nutrient absorption in the C. elegans intestine

Ion channels are necessary for proper water and nutrient absorption in the intestine, which supports cellular metabolism and organismal growth. While a role for Na + co-transporters and pumps in intestinal nutrient absorption is well defined, how individual K + uniporters function to maintain ion homeostasis is poorly understood. Using Caenorhabditis elegans , we show that a gain-of-function mutation in twk-26 , which encodes a two-pore domain K + ion channel orthologous to human KCNK3, facilitates nutrient absorption and suppresses the metabolic and developmental defects displayed by impaired intestinal MAP Kinase (MAPK) signaling. Mutations in drl-1 and flr-4, which encode two components of this MAPK pathway, cause severe growth defects, reduced lipid storage, and a dramatic increase in autophagic lysosomes, which mirror dietary restriction phenotypes. Additionally, these MAPK mutants display structural defects of the intestine and an impaired defecation motor program. We find that activation of TWK-26 reverses the dietary restriction-like state of the MAPK mutants by restoring intestinal nutrient absorption without correcting the intestinal bloating or defecation defects. This study provides unique insight into the mechanisms by which intestinal K + ion channels support intestinal metabolic homeostasis.

New Function Annotation of PROSER2 in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis due to the absence of diagnostic markers and molecular targets. Here, we took an unconventional approach to identify new molecular targets for pancreatic cancer. We chose uncharacterized protein evidence level 1 without function annotation from extensive proteomic research on pancreatic cancer and focused on proline and serine-rich 2 (PROSER2), which ranked high in the cell membrane and cytoplasm. In our study using cell lines and patient-derived orthotopic xenograft cells, PROSER2 exhibited a higher expression in cells derived from primary tumors than in those from metastatic tissues. PROSER2 was localized in the cell membrane and cytosol by immunocytochemistry. PROSER2 overexpression significantly reduced the metastatic ability of cancer cells, whereas its suppression had the opposite effect. Proteomic analysis revealed that PROSER2 interacts with STK25 and PDCD10, and their binding was confirmed by immunoprecipitation and immunocytochemistry. STK25 knockdown enhanced metastasis by decreasing p-AMPK levels, whereas PROSER2-overexpressing cells increased the level of p-AMPK, indicating that PROSER2 suppresses invasion via the AMPK pathway by interacting with STK25. This is the first demonstration of the novel role of PROSER2 in antagonizing tumor progression via the STK25-AMPK pathway in PDAC. LC-MS/MS data are available at MassIVE (MSV000092953) and ProteomeXchange (PXD045646).

Lipid Metabolism as a Potential Target of Liver Cancer

Hepatocellular carcinoma (HCC) stands as a severe malignant tumor with a profound impact on overall health, often accompanied by an unfavorable prognosis. Despite some advancements in the diagnosis and treatment of this disease, improving the prognosis of HCC remains a formidable challenge. It is noteworthy that lipid metabolism plays a pivotal role in the onset, development, and progression of tumor cells. Existing research indicates the potential application of targeting lipid metabolism in the treatment of HCC. This review aims to thoroughly explore the alterations in lipid metabolism in HCC, offering a detailed account of the potential advantages associated with innovative therapeutic strategies targeting lipid metabolism. Targeting lipid metabolism holds promise for potentially enhancing the prognosis of HCC.

Cellular Impacts of Striatins and the STRIPAK Complex and Their Roles in the Development and Metastasis in Clinical Cancers (Review)

Striatins (STRNs) are generally considered to be cytoplasmic proteins, with lower expression observed in the nucleus and at cell-cell contact regions. Together with protein phosphatase 2A (PP2A), STRNs form the core region of striatin-interacting phosphatase and kinase (STRIPAK) complexes through the coiled-coil region of STRN proteins, which is crucial for substrate recruitment. Over the past two decades, there has been an increasing amount of research into the biological and cellular functions of STRIPAK members. STRNs and the constituent members of the STRIPAK complex have been found to regulate several cellular functions, such as cell cycle control, cell growth, and motility. Dysregulation of these cellular events is associated with cancer development. Importantly, their roles in cancer cells and clinical cancers are becoming recognised, with several STRIPAK components found to have elevated expression in cancerous tissues compared to healthy tissues. These molecules exhibit significant diagnostic and prognostic value across different cancer types and in metastatic progression. The present review comprehensively summarises and discusses the current knowledge of STRNs and core STRIPAK members, in cancer malignancy, from both cellular and clinical perspectives.

STK25: a viable therapeutic target for cancer treatments?

Serine/threonine protein kinase 25 (STK25) is a critical regulator of ectopic lipid storage, glucose and insulin homeostasis, fibrosis, and meta-inflammation. More and more studies have revealed a strong correlation between STK25 and human diseases. On the one hand, STK25 can affect glucose and fatty acid metabolism in normal cells or tumors. On the other hand, STK25 participates in autophagy, cell polarity, cell apoptosis, and cell migration by activating various signaling pathways. This article reviews the composition and function of STK25, the energy metabolism and potential drugs that may target STK25, and the research progress of STK25 in the occurrence and development of tumors, to provide a reference for the clinical treatment of tumors.

CircTNPO3 promotes hepatocellular carcinoma progression by sponging miR-199b-5p and regulating STRN expression

Hepatocellular carcinoma (HCC) is the most common primary liver tumor, which seriously threatens human health. CircTNPO3 was up-regulated in HCC tissues. However, the regulatory mechanism of circTNPO3 in HCC was still unclear. We aimed to investigate the circTNPO3 function in the development of HCC. qRT-PCR and Western blot examined gene and protein levels. CCK8, EdU, flow cytometry, and Transwell assays were used to detect cell viability, proliferation, apoptosis, and invasion abilities. Dual-luciferase reporter and RIP assays determined the relationship between circTNPO3, miR-199b-5p, and striatin (STRN). The effect of CircTNPO3 on HCC progress was investigated in vivo. CircTNPO3 and STRN were significantly increased, while miR-199b-5p was repressed in HCC tissues or cells. Afterward, miR-199b-5p was negatively correlated with STRN. circTNPO3 was positively correlated with STRN. Knockdown of circTNPO3 inhibited cell viability, proliferation, invasion, and promoted apoptosis, while circTNPO3 overexpression had the opposite results. Furthermore, miR-199b-5p inhibition could eliminate the regulatory effect of sh-circTNPO3 on the proliferation and apoptosis in HCC cells. CircTNPO3 positively regulated STRN expression by targeting miR-199b-5p. MiR-199b-5p suppressed HCC progression by inhibiting STRN expression. Tumor formation in nude mice showed that knockdown of circTNPO3 significantly inhibited tumor growth and suppressed ki-67 levels. CircTNPO3 promoted HCC progression through regulating STRN expression by sponging miR-199b-5p, which provided a strategy for HCC treatment.

Oxidative stress genes in patients with esophageal squamous cell carcinoma: construction of a novel prognostic signature and characterization of tumor microenvironment infiltration

Background

Oxidative stress plays an important role in the progression of various types of tumors. However, its role in esophageal squamous cell carcinoma (ESCC) has seldom been explored. This study aimed to discover prognostic markers associated with oxidative stress in ESCC to improve the prediction of prognosis and help in the selection of effective immunotherapy for patients.

Results

A consensus cluster was constructed using 14 prognostic differentially expressed oxidative stress-related genes (DEOSGs) that were remarkably related to the prognosis of patients with ESCC. The infiltration levels of neutrophils, plasma cells, and activated mast cells, along with immune score, stromal score, and estimated score, were higher in cluster 1 than in cluster 2. A prognostic signature based on 10 prognostic DEOSGs was devised that could evaluate the prognosis of patients with ESCC. Calculated risk score proved to be an independent clinical prognostic factor in the training, testing, and entire sets. P53 signaling pathway was highly enriched in the high-risk group. The calculated risk score was positively related to the infiltration levels of resting mast cells, memory B cells, and activated natural killer (NK) cells and negatively associated with the infiltration levels of M1 and M2 macrophages. The relationship between clinical characteristics and risk score has not been certified. The half-maximal inhibitory concentration (IC50) values for sorafenib and gefitinib were lower for patients in the low-risk group.

Conclusion

Our prognostic signature based on 10 prognostic DEOSGs could predict the disease outcomes of patients with ESCC and had strong clinical value. Our study improves the understanding of oxidative stress in tumor immune microenvironment (TIME) and provides insights for developing improved and efficient immunotherapy strategies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12859-022-04956-9.

Metabolic Pathways in Breast Cancer Reprograming: An Insight to Non-Coding RNAs

Cancer cells reprogram their metabolisms to achieve high energetic requirements and produce precursors that facilitate uncontrolled cell proliferation. Metabolic reprograming involves not only the dysregulation in glucose-metabolizing regulatory enzymes, but also the enzymes engaging in the lipid and amino acid metabolisms. Nevertheless, the underlying regulatory mechanisms of reprograming are not fully understood. Non-coding RNAs (ncRNAs) as functional RNA molecules cannot translate into proteins, but they do play a regulatory role in gene expression. Moreover, ncRNAs have been demonstrated to be implicated in the metabolic modulations in breast cancer (BC) by regulating the metabolic-related enzymes. Here, we will focus on the regulatory involvement of ncRNAs (microRNA, circular RNA and long ncRNA) in BC metabolism, including glucose, lipid and glutamine metabolism. Investigation of this aspect may not only alter the approaches of BC diagnosis and prognosis, but may also open a new avenue in using ncRNA-based therapeutics for BC treatment by targeting different metabolic pathways.

GCKIII kinases in lipotoxicity: Roles in NAFLD and beyond

Nonalcoholic fatty liver disease (NAFLD) is defined by excessive accumulation of lipid droplets within hepatocytes. The STE20‐type kinases comprising the germinal center kinase III (GCKIII) subfamily – MST3, MST4, and STK25 – decorate intrahepatocellular lipid droplets and have recently emerged as critical regulators of the initiation and progression of NAFLD. While significant advancement has been made toward deciphering the role of GCKIII kinases in hepatic fat accumulation (i.e., steatosis) as well as the aggravation of NAFLD into its severe form nonalcoholic steatohepatitis (NASH), much remains to be resolved. This review provides a brief overview of the recent studies in patient cohorts, cultured human cells, and mouse models, which have characterized the function of MST3, MST4, and STK25 in the regulation of hepatic lipid accretion, meta‐inflammation, and associated cell damage in the context of NAFLD/NASH. We also highlight the conflicting data and emphasize future research directions that are needed to advance our understanding of GCKIII kinases as potential targets in the therapy of NAFLD and its comorbidities. Conclusions: Several lines of evidence suggest that GCKIII proteins govern the susceptibility to hepatic lipotoxicity and that pharmacological inhibition of these kinases could mitigate NAFLD development and aggravation. Comprehensive characterization of the molecular mode‐of‐action of MST3, MST4, and STK25 in hepatocytes as well as extrahepatic tissues is important, especially in relation to their impact on carcinogenesis, to fully understand the efficacy as well as safety of GCKIII antagonism.