PCK1 Regulates Glycolysis and Tumor Progression in Clear Cell Renal Cell Carcinoma Through LDHA

Prediction of novel biomarkers for gastric intestinal metaplasia and gastric adenocarcinoma using bioinformatics analysis

Background & aim

The histologic and molecular changes from intestinal metaplasia (IM) to gastric cancer (GC) have not been fully characterized. The present study sought to identify potential alterations in signaling pathways in IM and GC to predict disease progression; these alterations can be considered therapeutic targets.

Materials & methods

Seven gene expression profiles were selected from the GEO database. Discriminate differentially expressed genes (DEGs) were analyzed by EnrichR. The STRING database, Cytoscape, Gene Expression Profiling Interactive Analysis (GEPIA), cBioPortal, NetworkAnalyst, MirWalk database, OncomiR, and bipartite miRNA‒mRNA correlation network was used for downstream analyses of selected module genes.

Results

Analyses revealed that extracellular matrix-receptor interactions (ITGB1, COL1A1, COL1A2, COL4A1, FN1, COL6A3, and THBS2) in GC and PPAR signaling pathway interactions (FABP1, APOC3, APOA1, HMGCS2, and PPARA and PCK1) in IM may play key roles in both the carcinogenesis and progression of underlying GC from intestinal metaplasia. IM enrichment indicated that this is closely related to digestion and absorption. The TF-hub gene regulatory network revealed that AR, TCF4, SALL4, and ESR1 were more important for hub gene expression. It was revealed that the development and prediction of GC may be affected by hsa-miR-29. It was found that PTGR1, C1orf115, CRYL1, ALDOB, and SULT1B1 were downregulated in GC and upregulated in IM. Therefore, they might have tumor suppressor activity in GC progression.

Conclusion

New potential biomarkers and pathways involved in GC and IM were identified that are important for the transformation of GC from IM to adenocarcinoma and can be therapeutic targets for GC.

Metabolic alterations in hereditary and sporadic renal cell carcinoma

Kidney cancer is the seventh leading cause of cancer in the world, and its incidence is on the rise. Renal cell carcinoma (RCC) is the most common form and is a heterogeneous disease comprising three major subtypes that vary in their histology, clinical course and driver mutations. These subtypes include clear cell RCC, papillary RCC and chromophobe RCC. Molecular analyses of hereditary and sporadic forms of RCC have revealed that this complex and deadly disease is characterized by metabolic pathway alterations in cancer cells that lead to deregulated oxygen and nutrient sensing, as well as impaired tricarboxylic acid cycle activity. These metabolic changes facilitate tumour growth and survival. Specifically, studies of the metabolic features of RCC have led to the discovery of oncometabolites - fumarate and succinate - that can promote tumorigenesis, moonlighting functions of enzymes, and substrate auxotrophy owing to the disruption of pathways that enable the production of arginine and cholesterol. These metabolic alterations within RCC can be exploited to identify new therapeutic targets and interventions, in combination with novel approaches that minimize the systemic toxicity of metabolic inhibitors and reduce the risk of drug resistance owing to metabolic plasticity.

SLC9A2, suppressing by the transcription suppressor ETS1, restrains growth and invasion of osteosarcoma via inhibition of aerobic glycolysis

Recent studies have shown that Solute Carrier Family 9 Member A2 (SLC9A2) could serve as a biomarker for cancer. However, its mechanism of action in osteosarcoma (OS) was still unclear. In this study, the data sets GSE154530 and GSE99671 were downloaded from the Gene Expression Omnibus (GEO) database, and 31 differentially expressed genes (DEGs) related to methylation were screened by bioinformatics analysis tools. Subsequently, SLC9A2 was screened as a candidate gene from DEGs, which was significantly downregulated in OS. CCK-8, transwell, western blotting and Seahorse XFe24 Cell Metabolic Analyzer assays demonstrated that overexpression of SLC9A2 could constrain OS cell proliferation, invasion, and aerobic glycolysis. Dual-luciferase reporter gene assay and chromatin immunoprecipitation (ChIP) assays indicated ETS proto-oncogene 1 (ETS1) was a transcription suppressor of SLC9A2, and overexpression of ETS1 could promote methylation levels in specific regions of the SLC9A2 promoter. ETS1 could promote the proliferation, invasion, and aerobic glycolysis ability of OS cells, as well as tumor growth in vivo by inhibiting the expression of SLC9A2. In addition, SLC9A2, suppressing by ETS1, restrains growth and invasion of OS via inhibition of aerobic glycolysis. Thus, SLC9A2 can function as a key inhibitory factor in the aerobic glycolysis to inhibit proliferation and invasion of OS. This indicated that SLC9A2 has a potential targeted therapeutic effect on OS.

Two-Dimensional-PAGE Coupled with nLC-MS/MS-Based Identification of Differentially Expressed Proteins and Tumorigenic Pathways in MCF7 Breast Cancer Cells Transfected for JTB Protein Silencing

The identification of new cancer-associated genes/proteins, the characterization of their expression variation, the interactomics-based assessment of differentially expressed genes/proteins (DEGs/DEPs), and understanding the tumorigenic pathways and biological processes involved in BC genesis and progression are necessary and possible by the rapid and recent advances in bioinformatics and molecular profiling strategies. Taking into account the opinion of other authors, as well as based on our own team's in vitro studies, we suggest that the human jumping translocation breakpoint (hJTB) protein might be considered as a tumor biomarker for BC and should be studied as a target for BC therapy. In this study, we identify DEPs, carcinogenic pathways, and biological processes associated with JTB silencing, using 2D-PAGE coupled with nano-liquid chromatography tandem mass spectrometry (nLC-MS/MS) proteomics applied to a MCF7 breast cancer cell line, for complementing and completing our previous results based on SDS-PAGE, as well as in-solution proteomics of MCF7 cells transfected for JTB downregulation. The functions of significant DEPs are analyzed using GSEA and KEGG analyses. Almost all DEPs exert pro-tumorigenic effects in the JTBlow condition, sustaining the tumor suppressive function of JTB. Thus, the identified DEPs are involved in several signaling and metabolic pathways that play pro-tumorigenic roles: EMT, ERK/MAPK, PI3K/AKT, Wnt/β-catenin, mTOR, C-MYC, NF-κB, IFN-γ and IFN-α responses, UPR, and glycolysis/gluconeogenesis. These pathways sustain cancer cell growth, adhesion, survival, proliferation, invasion, metastasis, resistance to apoptosis, tight junctions and cytoskeleton reorganization, the maintenance of stemness, metabolic reprogramming, survival in a hostile environment, and sustain a poor clinical outcome. In conclusion, JTB silencing might increase the neoplastic phenotype and behavior of the MCF7 BC cell line. The data is available via ProteomeXchange with the identifier PXD046265.

CENPE and LDHA were potential prognostic biomarkers of chromophobe renal cell carcinoma

BACKGROUND

Most sarcomatoid differentiated renal cell carcinoma was differentiated from Chromophobe renal cell carcinoma (KICH) and related to a bad prognosis. Thus, finding biomarkers is important for the therapy of KICH.

METHODS

The UCSC was used for determining the expression of mRNA and miRNA and clinical data in KICH and normal samples. KEGG and GO were used for predicting potential function of differently expressed genes (DEGs). Optimal prognostic markers were determined by Lasso regression. Kaplan-Meier survival, ROC, and cox regression were used for assessing prognosis value. GSEA was used for predicting potential function of markers. The relations between markers and immune cell infiltration were determined by Pearson method. The upstream miRNA of markers was predicted in TargetScan and DIANA.

RESULTS

The 6162 upregulated and 13,903 downregulated DEGs were identified in KICH. Further CENPE and LDHA were screened out as optimal prognostic risk signatures. CENPE was highly expressed while LDHA was lowly expressed in KICH samples, and the high expressions of 2 genes contributed to bad prognosis. The functions of CENPE and LDHA were mainly enriched in proliferation related pathways such as cell cycle and DNA replication. In addition, the correlation of 2 genes with immune infiltrates in KICH was also observed. Finally, we found that has-miR-577 was the common upstream of 2 genes and the binding sites can be predicted.

CONCLUSION

CENPE and LDHA were identified as the important prognostic biomarkers in KICH, and they might be involved in the proliferation of cancer cell.

ENO2 as a Biomarker Regulating Energy Metabolism to Promote Tumor Progression in Clear Cell Renal Cell Carcinoma

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is the most common and metastatic type of renal cell carcinoma. Despite significant advancements, the current diagnostic biomarkers for ccRCC lack the desired specificity and sensitivity, necessitating the identification of novel biomarkers and elucidation of their underlying mechanisms.

METHODS

Three gene expression profile datasets were obtained from the GEO database, and differentially expressed genes (DEGs) were screened. Gene Ontology and KEGG pathway analysis were conducted in ccRCC. To clarify the diagnosis and prognostic role of ENO2, Kaplan-Meier analysis and Cox proportional hazards regression analysis were performed. Functional experiments were also carried out to verify the significant role of ENO2 in ccRCC. Finally, tumor mutational burden analysis was utilized to investigate the potential role of ENO2 in gene mutations in ccRCC.

RESULTS

The study showed that ENO2 is a potential biomarker for the diagnosis of ccRCC and can independently predict the clinical prognosis of ccRCC. Furthermore, we found that ENO2 can promote the occurrence and progression of ccRCC by affecting the glycolysis level of cells through the "Warburg effect".

CONCLUSIONS

These findings provide new theories for the occurrence and development of ccRCC and can help formulate new strategies for its diagnosis and treatment.

Emerging roles of cytosolic phosphoenolpyruvate kinase 1 (PCK1) in cancer

Although it was traditionally believed that gluconeogenesis enzymes were absent from cancers that did not originate in gluconeogenic organs, numerous investigations have shown that they are functionally expressed in a variety of tumors as mediators of shortened forms of Gluconeogenesis. One of the isomers of PEPCK, the first-rate limiting enzyme in gluconeogenesis, is PCK 1, which catalyzes the conversion of oxaloacetate (OAA) and GTP into PEP, CO2, and GDP. It is also known as PEPCK-C or PCK1, and it is cytosolic. Despite being paradoxical, it has been demonstrated that, in addition to its enzymatic role in normal metabolism, this enzyme also plays a role in tumors that arise in gluconeogenic and non-gluconeogenic organs. According to newly available research, it has metabolic and non-metabolic roles in tumor progression and development. Thus, this review will give insight into PCK1 relationship, function, and mechanism in or with different types of cancer using contemporary findings.

Restoring gluconeogenesis by TEF inhibited proliferation and promoted apoptosis and immune surveillance in kidney renal clear cell carcinoma

BACKGROUND

Kidney renal clear cell carcinoma (KIRC) is the major histological subtype of kidney tumor which covers approximately 80% of the cases. Although various therapies have been developed, the clinical outcome remains unsatisfactory. Metabolic dysregulation is a key feature of KIRC, which impacts progression and prognosis of the disease. Therefore, understanding of the metabolic changes in KIRC is of great significance in improving the treatment outcomes.

METHODS

The glycolysis/gluconeogenesis genes were analyzed in the KIRC transcriptome from the Cancer Genome Atlas (TCGA) by the different expression genes (DEGs) test and survival analysis. The gluconeogenesis-related miRNAs were identified by ImmuLncRNA. The expression levels of indicated genes and miRNAs were validated in KIRC tumor and adjunct tissues by QPCR. The effects of miR-4477b and PCK1 on cell proliferation and apoptosis were examined using the cell viability assay, cell apoptosis assay, and clone information. The interaction of miR-4477b with TEF was tested by the luciferase report gene assay. The different gluconeogenesis statuses of tumor cells and related signatures were investigated by single-cell RNA sequencing (scRNA-seq) analysis.

RESULTS

The 11 gluconeogenesis genes were found to be suppressed in KIRC (referring as PGNGs), and the less suppression of PGNGs indicated better survival outcomes. Among the 11 PGNGs, we validated four rate-limiting enzyme genes in clinical tumor patients. Moreover, restoring gluconeogenesis by overexpressing PCK1 or TEF through miR-4477b inhibition significantly inhibited tumor cell proliferation, colony formation, and induced cell apoptosis in vitro. Independent single-cell RNA sequencing (scRNA-seq) data analysis revealed that the tumor cells had high levels of PGNG expression (PGNG + tumor cells) represented a phenotype of early stage of neoplasia and prompted immune surveillance.

CONCLUSIONS

Our study suggests that the deficiency of gluconeogenesis is a key metabolic feature of KIRC, and restoring gluconeogenesis could effectively inhibit the proliferation and progression of KIRC cells.

PCK1 activates oncogenic autophagy via down-regulation Serine phosphorylation of UBAP2L and antagonizes colorectal cancer growth

Phosphoenolpyruvate carboxykinase 1 (PCK1) is the rate-limiting enzyme in gluconeogenesis. PCK1 is considered an anti-oncogene in several human cancers. In this study, we aimed to determine the functions of PCK1 in colorectal cancer (CRC). PCK1 expression in CRC tissues was tested by western blot and immunohistochemistry analyses and associations of PCK1 level with clinicopathological characteristics and disease survival evaluated. Further, we studied the effect of PCK1 on CRC cell proliferation and the underlying mechanisms. Our results show that PCK1 is expressed at significantly lower levels in CRC than in control tissues. High PCK1 expression was correlated with smaller tumor diameter and less bowel wall invasion (T stage). Overexpression and knockdown experiments demonstrated that PCK1 inhibits CRC cell growth both in vitro and in vivo. Mechanistically, PCK1 antagonizes CRC growth via inactivating UBAP2L phosphorylation at serine 454 and enhancing autophagy. Overall, our findings reveal a novel molecular mechanism involving PCK1 and autophagy, and highlight PCK1 as a promising candidate therapeutic target in CRC.

Role of phosphoenolpyruvate carboxykinase 1 (pck1) in mediating nutrient metabolism in zebrafish

Carbohydrates are the most economical source of energy in fish feeds, but most fish have limited ability to utilize carbohydrates. It has been reported that phosphoenolpyruvate carboxykinase 1 (pck1) is involved in carbohydrate metabolism, lipid metabolism, and other metabolic processes. However, direct evidence is lacking to fully understand the relationship between pck1 and glucose and lipid metabolism. Here, we generated a pck1 knockout zebrafish by CRISPR/cas9 system, and a high-carbohydrate diet was provided to 60 days post-fertilization (dpf) for 8 weeks. We found that pck1-deficient zebrafish displayed decreased plasma glucose, elevated mRNA levels of glycolysis-related genes (gck, pfk, pk), and reduced the transcriptional levels of gluconeogenic genes (pck1, fbp1a) in liver. We also found decreased triglyceride, total cholesterol, and lipid accumulation and in pck1^-/- zebrafish, along with downregulation of genes for lipolysis (acaca) and lipogenesis (cpt1). In addition, the observation of HE staining revealed that the total muscle area of pck1^-/- was substantially less than that of WT zebrafish and real-time PCR suggested that GH/IGF-1 signaling (ulk2, stat1b) may be suppressed in pck1-deficient fish. Taken together, these findings suggested that pck1 may play an important role in the high-carbohydrate diet utilization of fish and significantly affected lipid metabolism and protein synthesis in zebrafish. pck1 knockout mutant line could facilitate a further mechanism study of pck1-associated metabolic regulation and provide new information for improving carbohydrate utilization traits.

The role and potential mechanism of O-Glycosylation in gastrointestinal tumors

Glycosylation is a critical post-translational modification (PTM) that affects the function of proteins and regulates cell signaling, thereby regulating various biological processes. Protein oxygen-N-acetylglucosamine (O-GlcNAc) glycosylation modifications are glycochemical modifications that occur within cells in the signal transduction and are frequently found in the cytoplasm and nucleus. Due to the rapid and reversible addition and removal, O-GlcNAc modifications are able to reversibly compete with certain phosphorylation modifications, immediately regulate the activity of proteins, and participate in kinds of cellular metabolic and signal transduction pathways, playing a pivotal role in the regulation of tumors, diabetes, and other diseases. This article provided a brief overview of O-GlcNAc glycosylation modification, introduced its role in altering the progression and immune response regulation of gastrointestinal tumors, and discussed its potential use as a marker of tumor neogenesis.

PCK1 dysregulation in cancer: Metabolic reprogramming, oncogenic activation, and therapeutic opportunities

The last few decades have witnessed an advancement in our understanding of multiple cancer cell pathways related to metabolic reprogramming. One of the most important cancer hallmarks, including aerobic glycolysis (the Warburg effect), the central carbon pathway, and multiple-branch metabolic pathway remodeling, enables tumor growth, progression, and metastasis. Phosphoenolpyruvate carboxykinase 1 (PCK1), a key rate-limiting enzyme in gluconeogenesis, catalyzes the conversion of oxaloacetate to phosphoenolpyruvate. PCK1 expression in gluconeogenic tissues is tightly regulated during fasting. In tumor cells, PCK1 is regulated in a cell-autonomous manner rather than by hormones or nutrients in the extracellular environment. Interestingly, PCK1 has an anti-oncogenic role in gluconeogenic organs (the liver and kidneys), but a tumor-promoting role in cancers arising from non-gluconeogenic organs. Recent studies have revealed that PCK1 has metabolic and non-metabolic roles in multiple signaling networks linking metabolic and oncogenic pathways. Aberrant PCK1 expression results in the activation of oncogenic pathways, accompanied by metabolic reprogramming, to maintain tumorigenesis. In this review, we summarize the mechanisms underlying PCK1 expression and regulation, and clarify the crosstalk between aberrant PCK1 expression, metabolic rewiring, and signaling pathway activation. In addition, we highlight the clinical relevance of PCK1 and its value as a putative cancer therapeutic target.

Increased glucosylceramide production leads to decreased cell energy metabolism and lowered tumor marker expression in non-cancerous liver cells

Hepatocellular carcinoma (HCC) is one of the most difficult cancer types to treat. Liver cancer is often diagnosed at late stages and therapeutic treatment is frequently accompanied by development of multidrug resistance. This leads to poor outcomes for cancer patients. Understanding the fundamental molecular mechanisms leading to liver cancer development is crucial for developing new therapeutic approaches, which are more efficient in treating cancer. Mice with a liver specific UDP-glucose ceramide glucosyltransferase (UGCG) knockout (KO) show delayed diethylnitrosamine (DEN)-induced liver tumor growth. Accordingly, the rationale for our study was to determine whether UGCG overexpression is sufficient to drive cancer phenotypes in liver cells. We investigated the effect of UGCG overexpression (OE) on normal murine liver (NMuLi) cells. Increased UGCG expression results in decreased mitochondrial respiration and glycolysis, which is reversible by treatment with EtDO-P4, an UGCG inhibitor. Furthermore, tumor markers such as FGF21 and EPCAM are lowered following UGCG OE, which could be related to glucosylceramide (GlcCer) and lactosylceramide (LacCer) accumulation in glycosphingolipid-enriched microdomains (GEMs) and subsequently altered signaling protein phosphorylation. These cellular processes lead to decreased proliferation in NMuLi/UGCG OE cells. Our data show that increased UGCG expression itself does not induce pro-cancerous processes in normal liver cells, which indicates that increased GlcCer expression leads to different outcomes in different cancer types.

Identification of Prognostic Metabolism-Related Genes in Clear Cell Renal Cell Carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) is a cancer with abnormal metabolism. The purpose of this study was to investigate the effect of metabolism-related genes on the prognosis of ccRCC patients.

Methods

The data of ccRCC patients were downloaded from the TCGA and the GEO databases and clustered using the nonnegative matrix factorization method. The limma software package was used to analyze differences in gene expression. A random forest model was used to screen for important genes. A novel Riskscore model was established using multivariate regression. The model was evaluated based on the metabolic pathway, immune infiltration, immune checkpoint, and clinical characteristics.

Results

According to metabolism-related genes, kidney clear cell carcinoma (KIRC) datasets downloaded from TCGA were clustered into two groups and showed significant differences in prognosis and immune infiltration. There were 667 differentially expressed genes between the two clusters, of which 408 were screened by univariate analysis. Finally, 12 differentially expressed genes (MDK, SLC1A1, SGCB, C4orf3, MALAT1, PILRB, IGHG1, FZD1, IFITM1, MUC20, KRT80, and SALL1) were filtered out using the random forest model. The model of Riskscore was obtained by multiplying the expression levels of these 12 genes with the corresponding coefficients of the multivariate regression. We found that the Riskscore correlated with the expression of these 12 genes; the high Riskscore matched the low survival rate verified in the verification set. The analysis found that the Riskscore model was associated with most of the metabolic processes, immune infiltration of cells such as plasma cells, immune checkpoints such as PD-1, and clinical characteristics such as M stage.

Conclusion

We established a new Riskscore model for the prognosis of ccRCC based on metabolism. The genes in the model provided several novel targets for the study of ccRCC.

The Uniqueness of Clear Cell Renal Cell Carcinoma: Summary of the Process and Abnormality of Glucose Metabolism and Lipid Metabolism in ccRCC

Kidney cancer is a cancer with an increasing incidence in recent years. Clear cell renal cell carcinoma (ccRCC) accounts for up to 80% of all kidney cancers. The understanding of the pathogenesis, tumor progression, and metastasis of renal carcinoma is not yet perfect. Kidney cancer has some characteristics that distinguish it from other cancers, and the metabolic aspect is the most obvious. The specificity of glucose and lipid metabolism in kidney cancer cells has also led to its being studied as a metabolic disease. As the most common type of kidney cancer, ccRCC has many characteristics that represent the specificity of kidney cancer. There are features that we are very concerned about, including the presence of lipid droplets in cells and the obesity paradox. These two points are closely related to glucose metabolism and lipid metabolism. Therefore, we hope to explore whether metabolic changes affect the occurrence and development of kidney cancer by looking for evidence of changes on expression at the genomic and protein levels in glucose metabolism and lipid metabolism in ccRCC. We begin with the representative phenomenon of abnormal cancer metabolism: the Warburg effect, through the collection of popular metabolic pathways and related genes in the last decade, as well as some research hotspots, including the role of ferroptosis and glutamine in cancer, systematically elaborated the factors affecting the incidence and metastasis of kidney cancer. This review also identifies the similarities and differences between kidney cancer and other cancers in order to lay a theoretical foundation and provide a valid hypothesis for future research.

Identification of a glycolysis-related lncRNA prognostic signature for clear cell renal cell carcinoma

Background: The present study investigated the independent prognostic value of glycolysis-related long noncoding (lnc)RNAs in clear cell renal cell carcinoma (ccRCC).

Methods: A coexpression analysis of glycolysis-related mRNAs–long noncoding RNAs (lncRNAs) in ccRCC from The Cancer Genome Atlas (TCGA) was carried out. Clinical samples were randomly divided into training and validation sets. Univariate Cox regression and least absolute shrinkage and selection operator (LASSO) regression analyses were performed to establish a glycolysis risk model with prognostic value for ccRCC, which was validated in the training and validation sets and in the whole cohort by Kaplan–Meier, univariate and multivariate Cox regression, and receiver operating characteristic (ROC) curve analyses. Principal component analysis (PCA) and functional annotation by gene set enrichment analysis (GSEA) were performed to evaluate the risk model.

Results: We identified 297 glycolysis-associated lncRNAs in ccRCC; of these, 7 were found to have prognostic value in ccRCC patients by Kaplan–Meier, univariate and multivariate Cox regression, and ROC curve analyses. The results of the GSEA suggested a close association between the 7-lncRNA signature and glycolysis-related biological processes and pathways.

Conclusion: The seven identified glycolysis-related lncRNAs constitute an lncRNA signature with prognostic value for ccRCC and provide potential therapeutic targets for the treatment of ccRCC patients.

Metabolic Anti-Cancer Effects of Melatonin: Clinically Relevant Prospects

Metabolic reprogramming characterized by alterations in nutrient uptake and critical molecular pathways associated with cancer cell metabolism represents a fundamental process of malignant transformation. Melatonin (N-acetyl-5-methoxytryptamine) is a hormone secreted by the pineal gland. Melatonin primarily regulates circadian rhythms but also exerts anti-inflammatory, anti-depressant, antioxidant and anti-tumor activities. Concerning cancer metabolism, melatonin displays significant anticancer effects via the regulation of key components of aerobic glycolysis, gluconeogenesis, the pentose phosphate pathway (PPP) and lipid metabolism. Melatonin treatment affects glucose transporter (GLUT) expression, glucose-6-phosphate dehydrogenase (G6PDH) activity, lactate production and other metabolic contributors. Moreover, melatonin modulates critical players in cancer development, such as HIF-1 and p53. Taken together, melatonin has notable anti-cancer effects at malignancy initiation, progression and metastasing. Further investigations of melatonin impacts relevant for cancer metabolism are expected to create innovative approaches supportive for the effective prevention and targeted therapy of cancers.

Identifying Hypoxia Characteristics to Stratify Prognosis and Assess the Tumor Immune Microenvironment in Renal Cell Carcinoma

Background: Renal cell carcinoma (RCC) is a common malignant tumor worldwide, and immune checkpoint inhibitors are a new therapeutic option for metastatic RCC. Infiltrating immune cells in the tumor microenvironment (TME) play a critical part in RCC biology, which is important for tumor therapy and prediction. Hypoxia is a common condition that occurs in the TME and may lead to RCC immunosuppression and immune escape. This study was conducted to analyze the extent of the hypoxia immune microenvironment in the TME of RCC and develop a hypoxia-related risk model for predicting the prognosis of patients with RCC.

Methods: The gene expression profiles of 526 patients with RCC were downloaded from The Cancer Genome Atlas database. Combined with the hallmark-hypoxia gene dataset downloaded from Gene Set Enrichment Analysis, prognosis-related hypoxia genes were selected by survival analysis. A protein–protein interaction network and functional enrichment analysis were performed. A hypoxia-related risk model predicting the prognosis of patients with RCC was established using the least absolute shrinkage and selection operator. Data of 91 cases downloaded from the International Cancer Genome Consortium (ICGC) database were used for validation. CIBERSORT was applied to analyze the fractions of 22 immune cell types in the TME of RCC between low- and high-risk groups. The expression profiles of immunomodulators and immunosuppressive cytokines were also analyzed.

Results: Ninety-three genes were significantly associated with poor overall survival of patients with RCC and were mainly involved in 10 pathways. Using the established hypoxia-related risk model, the receiver operating characteristic curves showed an accuracy of 76.1% (95% CI: 0.719–0.804), and Cox proportional hazards regression analysis revealed that the model was an independent predictor of the prognosis of patients with RCC [hazard ratio (HR) = 2.884; 95% CI: 2.090–3.979] (p < 0.001). Using the ICGC database, we verified that the low-risk score group had a better overall survival outcome than the high-risk group. Additionally, dividing the hypoxia risk score into high-risk and low-risk groups could predict the immune microenvironment of RCC.

Conclusions: We demonstrated that a hypoxia-related risk model can be used to predict the outcomes of patients with RCC and reflect the immune microenvironment of RCC, which may help improve the overall clinical response to immune checkpoint inhibitors.

Interplay Between Glucose Metabolism and Chromatin Modifications in Cancer

Cancer cells reprogram glucose metabolism to meet their malignant proliferation needs and survival under a variety of stress conditions. The prominent metabolic reprogram is aerobic glycolysis, which can help cells accumulate precursors for biosynthesis of macromolecules. In addition to glycolysis, recent studies show that gluconeogenesis and TCA cycle play important roles in tumorigenesis. Here, we provide a comprehensive review about the role of glycolysis, gluconeogenesis, and TCA cycle in tumorigenesis with an emphasis on revealing the novel functions of the relevant enzymes and metabolites. These functions include regulation of cell metabolism, gene expression, cell apoptosis and autophagy. We also summarize the effect of glucose metabolism on chromatin modifications and how this relationship leads to cancer development. Understanding the link between cancer cell metabolism and chromatin modifications will help develop more effective cancer treatments.

High Pretreatment LDH Predicts Poor Prognosis in Hypopharyngeal Cancer

Background

Elevated pretreatment lactate dehydrogenase (LDH) has been associated with poor prognosis in various malignancies; however, its prognostic role in hypopharyngeal cancer remains elusive. In this study, we aimed to assess the association between pretreatment LDH and clinical outcome of hypopharyngeal cancer.

Methods

We retrospectively collected 198 hypopharyngeal cancer patients treated with surgery in our institution between 2004 and 2018. The prognostic role of pretreatment LDH was explored by using univariate and multivariate analyses. Besides, subgroup analysis was performed based on T stage.

Results

Three-year and Five-year of disease-free survival (DFS, 67.0 vs. 57.4%, 65.8 vs. 39.8%, p = 0.007) and overall survival (OS, 74.8 vs. 68.9%, 66.8 vs. 50.8%, p = 0.006) exhibited significant differences between low LDH level and high LDH level groups. Univariate analysis showed that pretreatment elevated serum LDH served as an unfavorable determinant with regard to DFS and OS. Further multivariate analysis also confirmed that LDH was an independent predictor for DFS and OS. Additionally, N status and age were also found to be significantly associated with both DFS and OS.

Conclusion

Pretreatment elevated serum LDH is an inferior prognostic factor for patients with hypopharyngeal cancer. These results should be validated by more multicenter and prospective studies.

Differential Expression of ADP/ATP Carriers as a Biomarker of Metabolic Remodeling and Survival in Kidney Cancers

ADP/ATP carriers (AACs) are mitochondrial transport proteins playing a strategic role in maintaining the respiratory chain activity, fueling the cell with ATP, and also regulating mitochondrial apoptosis. To understand if AACs might represent a new molecular target for cancer treatment, we evaluated AAC expression levels in cancer/normal tissue pairs available on the Tissue Cancer Genome Atlas database (TCGA), observing that AACs are dysregulated in most of the available samples. It was observed that at least two AACs showed a significant differential expression in all the available kidney cancer/normal tissue pairs. Thus, we investigated AAC expression in the corresponding kidney non-cancer (HK2)/cancer (RCC-Shaw and CaKi-1) cell lines, grown in complete medium or serum starvation, for investigating how metabolic alteration induced by different growth conditions might influence AAC expression and resistance to mitochondrial apoptosis initiators, such as "staurosporine" or the AAC highly selective inhibitor "carboxyatractyloside". Our analyses showed that AAC2 and AAC3 transcripts are more expressed than AAC1 in all the investigated kidney cell lines grown in complete medium, whereas serum starvation causes an increase of at least two AAC transcripts in kidney cancer cell lines compared to non-cancer cells. However, the total AAC protein content is decreased in the investigated cancer cell lines, above all in the serum-free medium. The observed decrease in AAC protein content might be responsible for the decrease of OXPHOS activity and for the observed lowered sensitivity to mitochondrial apoptosis induced by staurosporine or carboxyatractyloside. Notably, the cumulative probability of the survival of kidney cancer patients seriously decreases with the decrease of AAC1 expression in KIRC and KIRP tissues making AAC1 a possible new biomarker of metabolic remodeling and survival in kidney cancers.

LncRNA GA-Binding Protein Transcription Factor Subunit Beta-1 Antisense RNA 1 Inhibits Renal Carcinoma Growth Through an MiR-1246/Phosphoenolpyruvate Carboxykinase 1 Pathway

Objective

To clarify the role and mechanism of GABPB1-AS1 in renal cell carcinoma.

Methods

We collected 48 pairs of tumor and adjacent normal tissues from patients with clear cell renal cell carcinoma (ccRCC). Both 786-o and caki-1 ccRCC cell lines were transfected with GA-binding protein transcription factor subunit beta-1 antisense RNA 1 (GABPB1-AS1), miR-1246, or small interfering RNA phosphoenolpyruvate carboxykinase 1 (siPCK1) vectors. RNA expression was examined by quantitative reverse transcription-PCR and protein expression by Western blot. Cell proliferation was measured by Cell Counting Kit-8 assays. Cell migration and invasion were measured by transwell assays. Targeting relationships between genes were tested by luciferase reporter gene assays.

Results

Lower GABPB1-AS1 expression was found in ccRCC cells and tissues. GABPB1-AS1 expression was inversely associated with tumor size, TNM stage, and Furhman stage. High GABPB1-AS1 expression was associated with a better prognosis. GABPB1-AS1 overexpression significantly inhibited proliferation, migration, and invasion by 786-o and caki-1 cells. GABPB1-AS1 overexpression reduced tumor weights in xenograft experiments. Luciferase reporter assays showed that miR-1246 overexpression significantly inhibited the luciferase activity of 786-o and caki-1 cells transfected with wild-type (WT)-GABPB1-AS1 or WT-PCK1. Knockdown of PCK1 weakened the inhibition of proliferation, migration, and invasion induced by GABPB1-AS1 overexpression in 786-o and caki-1 cells.

Conclusion

GABPB1-AS1 inhibits ccRCC growth and plays a tumor suppressor role through an miR-1246/PCK1 axis.