Hypoxia-dependent expression of MAP17 coordinates the Warburg effect to tumor growth in hepatocellular carcinoma

Cellular senescence and metabolic reprogramming: Unraveling the intricate crosstalk in the immunosuppressive tumor microenvironment

The intrinsic oncogenic mechanisms and properties of the tumor microenvironment (TME) have been extensively investigated. Primary features of the TME include metabolic reprogramming, hypoxia, chronic inflammation, and tumor immunosuppression. Previous studies suggest that senescence-associated secretory phenotypes that mediate intercellular information exchange play a role in the dynamic evolution of the TME. Specifically, hypoxic adaptation, metabolic dysregulation, and phenotypic shifts in immune cells regulated by cellular senescence synergistically contribute to the development of an immunosuppressive microenvironment and chronic inflammation, thereby promoting the progression of tumor events. This review provides a comprehensive summary of the processes by which cellular senescence regulates the dynamic evolution of the tumor-adapted TME, with focus on the complex mechanisms underlying the relationship between senescence and changes in the biological functions of tumor cells. The available findings suggest that components of the TME collectively contribute to the progression of tumor events. The potential applications and challenges of targeted cellular senescence-based and combination therapies in clinical settings are further discussed within the context of advancing cellular senescence-related research.

FOXP2 suppresses the proliferation, invasion, and aerobic glycolysis of hepatocellular carcinoma cells by regulating the KDM5A/FBP1 axis

The Warburg effect is the preference of cancer cells to use glycolysis rather than oxidative phosphorylation to generate energy. Accumulating evidence suggests that aerobic glycolysis is widespread in hepatocellular carcinoma (HCC) and closely related to tumorigenesis. The purpose of this study was to investigate the role and mechanism of forkhead box P2 (FOXP2) in aerobic glycolysis and tumorigenesis in HCC. Here, we found that FOXP2 was lower expressed in HCC tissues and cells than in nontumor tissues and normal hepatocytes. Overexpression of FOXP2 suppressed cell proliferation and invasion of HCC cells and promoted cell apoptosis in vitro, and hindered the growth of mouse xenograft tumors in vivo. Further researches showed that FOXP2 inhibited the Warburg effect in HCC cells. Moreover, we demonstrated that FOXP2 up-regulated the expression of fructose-1, 6-diphosphatase (FBP1), and the inhibitory effect of FOXP2 on glycolysis was dependent on FBP1. Mechanistically, as a transcription factor, FOXP2 negatively regulated the transcription of lysine-specific demethylase 5A (KDM5A), and then blocked KDM5A-induced H3K4me3 demethylation in FBP1 promoter region, thereby promoting the expression of FBP1. Consistently, overexpressing KDM5A or silencing FBP1 effectively reversed the inhibitory effect of FOXP2 on HCC progression. Together, our findings revealed the mechanistic role of the FOXP2/KDM5A/FBP1 axis in glycolysis and malignant progression of HCC cells, providing a potential molecular target for the therapy of HCC.

Fenofibrate inhibits MOXD1 and PDZK1IP1 expression and improves lipid deposition and inflammation in mice with alcoholic fatty liver

AIMS

Alcoholic liver disease (ALD) can develop into cirrhosis and hepatocellular carcinoma but no specific drugs are available. Fenofibrate is therapeutically effective in ALD, however, the exact mechanism remains unknown. We explored the hub genes of ALD and the role of fenofibrate in ALD.

MAIN METHODS

The hub genes of ALD were screened by bioinformatics method, and their functional enrichment, signalling pathways, target genes and their correlation with immune microenvironment and pathogenic genes were analysed. We also analysed the binding affinity of fenofibrate to proteins of hub genes using molecular docking techniques, and the effects on hub gene expression, lipid deposition, oxidative stress and inflammation in the liver of National Institute on Alcohol Abuse and Alcoholism (NIAAA) model mice. The regulatory effects of fenofibrate on MOXD1 and PDZK1P1 were investigated after gene silencing of peroxisome proliferator-activated receptor-α (Ppar-α).

KEY FINDINGS

Hub genes identified, including monooxygenase DBH-like 1 (MOXD1), PDZK1-interacting protein 1 (PDZK1IP1) and solute carrier 51 β (SLC51B), are highly predictive for ALD. Hepatic MOXD1 and PDZK1IP1 expression was elevated in patients with ALD and NIAAA model mice, with no significant difference in SLC51B expression between the groups. Fenofibrate binds tightly to MOXD1 and PDZK1IP1, inhibits their hepatic expression independently of PPAR-α signalling, and ameliorates lipid deposition, oxidative stress and inflammatory responses in NIAAA model mice.

SIGNIFICANCE

MOXD1 and PDZK1IP1 are key genes in ALD progression; fenofibrate improves liver damage in NIAAA model mice by downregulating their expression. Our findings provide insight for improving diagnostic and therapeutic strategies for ALD.

Association between glycolysis markers and prognosis of liver cancer: a systematic review and meta-analysis

BACKGROUND

In recent years, the capacity of tumor cells to maintain high levels of glycolysis, even in the presence of oxygen, has emerged as one of the main metabolic traits and garnered considerable attention. The purpose of this meta-analysis is to investigate the prognostic value of glycolysis markers in liver cancer.

METHODS

PubMed, Embase, and Cochrane Library databases were searched for articles on glycolytic marker expression levels associated with the prognosis of liver cancer until April 2023. Stata SE14.0 was used to calculate the aggregate hazard ratios and 95% confidence intervals.

RESULTS

Thirty-five studies were included. The worse overall survival (OS) (P < 0.001), disease-free survival (DFS) (P = 0.001), recurrence-free survival (RFS) (P = 0.004), and time to recurrence (TTR) (P < 0.001) were significantly associated with elevated expression of glycolysis markers. Higher expression of PKM2 (P < 0.001), STMN1 (P = 0.002), MCT4 (P < 0.001), GLUT1 (P = 0.025), HK-2 (P < 0.001), and CA9 (P < 0.001) were significantly related to shorter OS. Increased levels of PKM2 (P < 0.001), CA9 (P = 0.005), and MCT4 (P < 0.001) were associated with worse DFS. Elevated PKM2 expression (P = 0.002) was also associated with poorer RFS in hepatocellular carcinoma patients. GLUT2 expression was not correlated with the prognosis of liver cancer (P = 0.134).

CONCLUSIONS

Elevated expression of glycolysis markers was associated with worse OS, DFS, RFS, and TTR in patients with liver cancer. Therefore, these glycolysis markers could serve as potential prognostic markers and therapeutic targets in liver cancer.

TRIAL REGISTRATION

PROSPERO registration: CRD42023469645.

PDZK1-interacting protein 1(PDZK1IP1) promotes subcutaneous preadipocyte proliferation in goats

PDZK1-interacting protein 1(PDZK1IP1), also known as MAP17, is encoded by the PDZK1IP1 gene and is a membrane-associated protein. PDZK1IP1 have been proven to be a potent regulator of cancer cell proliferation. However, the role of PDZK1IP1 in regulating goat subcutaneous preadipocyte proliferation is unknown. Here, we cloned the full-length coding sequence of PDZK1IP1 gene, investigated the potential functional of PDZK1IP1 in goat subcutaneous preadipocyte proliferation by gaining or losing function in vitro. Our results indicated that goat PDZK1IP1 gene consists of 345 bp, encoding a protein of 114 amino acids containing a typical PDZK1IP1 (MAP17) super family domain. Overexpression of PDZK1IP1 significantly increased the number of EdU-positive cells and cell viability, and also upregulated mRNA expression of cell proliferation-associated genes including CCND1 and CDK2 in vitro cultured cells. Conversely, knockdown of PDZK1IP1 mediated by siRNA technique significantly inhibited subcutaneous preadipocyte proliferation and downregulated mRNA expression of cell proliferation-associated genes including CCNE1, CCND1 and CDK2. Collectively, these results suggested that PDZK1IP1 can promote proliferation of goat subcutaneous preadipocyte.

The Significance of Microenvironmental and Circulating Lactate in Breast Cancer

Lactate represents the main product of pyruvate reduction catalyzed by the lactic dehydrogenase family of enzymes. Cancer cells utilize great quantities of glucose, shifting toward a glycolytic metabolism. With the contribution of tumor stromal cells and under hypoxic conditions, this leads toward the acidification of the extracellular matrix. The ability to shift between different metabolic pathways is a characteristic of breast cancer cells and is associated with an aggressive phenotype. Furthermore, the preliminary scientific evidence concerning the levels of circulating lactate in breast cancer points toward a correlation between hyperlactacidemia and poor prognosis, even though no clear linkage has been demonstrated. Overall, lactate may represent a promising metabolic target that needs to be investigated in breast cancer.

Hypoxia signaling in hepatocellular carcinoma: Challenges and therapeutic opportunities

Hepatocellular carcinoma (HCC) is one of the most common cancers with a relatively high cancer-related mortality. The uncontrolled proliferation of HCC consumes a significant amount of oxygen, causing the development of a hypoxic tumor microenvironment (TME). Hypoxia-inducible factors (HIFs), crucial regulators in the TME, activate several cancer hallmarks leading to the hepatocarcinogenesis of HCC and resistance to current therapeutics. As such, HIFs and their signaling pathways have been explored as potential therapeutic targets for the future management of HCC. This review discusses the current understanding of the structure and function of HIFs and their complex relationship with the various cancer hallmarks. To address tumor hypoxia, this review provides an insight into the various potential novel therapeutic agents for managing HCC, such as hypoxia-activated prodrugs, HIF inhibitors, nanomaterials, antisense oligonucleotides, and natural compounds, that target HIFs/hypoxic signaling pathways in HCC. Because of HCC's relatively high incidence and mortality rates in the past decades, greater efforts should be put in place to explore novel therapeutic approaches to improve the outcome for HCC patients.

LINC00853 contributes to tumor stemness of gastric cancer through FOXP3-mediated transcription of PDZK1IP1

BACKGROUND

The incidence and mortality of gastric cancer (GC) are high worldwide. Tumor stemness is a major contributor to tumorigenesis and development of GC, in which long non-coding RNAs (lncRNAs) are deeply involved. The purpose of this study was to investigate the influences and mechanisms of LINC00853 in the progression and stemness of GC.

METHODS

The level of LINC00853 was assessed based on The Cancer Genome Atlas (TCGA) database and GC cell lines by RT-PCR and in situ hybridization. An evaluation of biological functions of LINC00853 including cell proliferation, migration, and tumor stemness was conducted via gain-and loss-of-function experiments. Furthermore, RNA pull-down and RNA immunoprecipitation (RIP) assay were utilized to validate the connection between LINC00853 and the transcription factor Forkhead Box P3 (FOXP3). Nude mouse xenograft model was used to identify the impacts of LINC00853 on tumor development.

RESULTS

We identified the up-regulated levels of lncRNA-LINC00853 in GC, and its overexpression correlates with poor prognosis in GC patients. Further study indicated that LINC00853 promoted cell proliferation, migration and cancer stemness while suppressed cell apoptosis. Mechanistically, LINC00853 directly bind to FOXP3 and promoted FOXP3-mediated transcription of PDZK1 interacting protein 1(PDZK1IP1). Alterations of FOXP3 or PDZK1IP1 reversed the LINC00853-induced biological effects on cell proliferation, migration and stemness. Moreover, xenograft tumor assay was used to investigate the function of LINC00853 in vivo.

CONCLUSIONS

Taken together, these findings revealed the tumor-promoting activity of LINC00853 in GC, expanding our understanding of lncRNAs regulation on GC pathogenesis.

ACE2 negatively regulates the Warburg effect and suppresses hepatocellular carcinoma progression via reducing ROS-HIF1α activity

Aerobic glycolysis has pleiotropic roles in the pathogenesis of hepatocellular carcinoma (HCC). Emerging studies revealed key promoters of aerobic glycolysis, however, little is known about its negative regulators in HCC. In this study, an integrative analysis identifies a repertoire of differentially expressed genes (DNASE1L3, SLC22A1, ACE2, CES3, CCL14, GYS2, ADH4, and CFHR3) that are inversely associated with the glycolytic phenotype in HCC. ACE2, a member of the rennin-angiotensin system, is revealed to be downregulated in HCC and predicts a poor prognosis. ACE2 overexpression significantly inhibits the glycolytic flux as evidenced by reduced glucose uptake, lactate release, extracellular acidification rate, and the expression of glycolytic genes. Opposite results are noticed in loss-of-function studies. Mechanistically, ACE2 metabolizes Ang II to Ang-(1-7), which activates Mas receptor and leads to the phosphorylation of Src homology 2-containing inositol phosphatase 2 (SHP-2). SHP2 activation further blocks reactive oxygen species (ROS)-HIF1α signaling. Addition of Ang-(1-7) or the antioxidant N-acetylcysteine compromises in vivo additive tumor growth and aerobic glycolysis induced by ACE2 knockdown. Moreover, growth advantages afforded by ACE2 knockdown are largely glycolysis-dependent. In clinical settings, a close link between ACE2 expression and HIF1α or the phosphorated level of SHP2 is found. Overexpression of ACE2 significantly retards tumor growth in patient-derived xenograft model. Collectively, our findings suggest that ACE2 is a negative glycolytic regulator, and targeting the ACE2/Ang-(1-7)/Mas receptor/ROS/HIF1α axis may be a promising therapeutic strategy for HCC treatment.

A local tumor microenvironment acquired super-enhancer induces an oncogenic driver in colorectal carcinoma

Tumors exhibit enhancer reprogramming compared to normal tissue. The etiology is largely attributed to cell-intrinsic genomic alterations. Here, using freshly resected primary CRC tumors and patient-matched adjacent normal colon, we find divergent epigenetic landscapes between CRC tumors and cell lines. Intriguingly, this phenomenon extends to highly recurrent aberrant super-enhancers gained in CRC over normal. We find one such super-enhancer activated in epithelial cancer cells due to surrounding inflammation in the tumor microenvironment. We restore this super-enhancer and its expressed gene, PDZK1IP1, following treatment with cytokines or xenotransplantation into nude mice, thus demonstrating cell-extrinsic etiology. We demonstrate mechanistically that PDZK1IP1 enhances the reductive capacity CRC cancer cells via the pentose phosphate pathway. We show this activation enables efficient growth under oxidative conditions, challenging the previous notion that PDZK1IP1 acts as a tumor suppressor in CRC. Collectively, these observations highlight the significance of epigenomic profiling on primary specimens.

NXPH4 Promotes Gemcitabine Resistance in Bladder Cancer by Enhancing Reactive Oxygen Species and Glycolysis Activation through Modulating NDUFA4L2

Bladder cancer is one of the most prevalent kinds of cancer worldwide, and resistance to gemcitabine is a major problem for patients. The pathogenesis of bladder cancer and mechanism of resistance to chemotherapy remain to be explored. Through bioinformatics analysis, we first found that NXPH4 was independently related to the prognosis of patients with bladder cancer. Through wound healing assays, transwell invasion assays, and plate clone formation assays, we found that NXPH4 promoted the proliferation, migration, and invasion of bladder cancer cells. The induced gemcitabine resistance cell line also showed a higher expression of NXPH4. A glycolytic activity assay demonstrated that the expression of NXPH4 was positively related to glycolysis. A higher level of reactive oxygen species caused by enhanced levels of NXPH4 was found in gemcitabine-resistant cell lines. NDUFA4L2, glycolysis, and reactive oxygen species were shown to be essential for NXPH4-regulated functions through rescue assays in cell lines. The roles of NXPH4-regulated glycolysis, gemcitabine resistance, and NDUFA4L2 were validated in vivo as well. Our results imply that NXPH4 contributes to the proliferation, migration, and invasion of bladder cancer by maintaining the stability of NDUFA4L2 and consequently activating reactive oxygen species and glycolysis.