The Metabolic Basis of Kidney Cancer

Prevailing challenges in personalized treatment for metastatic renal cell carcinoma: a narrative review

INTRODUCTION

The management of metastatic renal cell carcinoma (mRCC) has advanced with recent therapies, yet optimizing treatment remains challenging due to disease heterogeneity and the growing number of options. Integrating systemic and local treatments requires a multidisciplinary approach to improve outcomes.

AREA COVERED

This review summarizes recent developments in treatment for mRCC. Upfront immuno-oncology (IO)-based combinations have improved survival, though concerns about overtreatment and toxicity persist. While the role of cytoreductive nephrectomy (CN) has declined to some extent, it may still benefit well-selected patients. Metastasis-directed therapies, including metastasectomy and stereotactic radiotherapy, provide prognostic value, particularly for oligometastatic lesions or brain metastases. Comprehensive genomic profiling (CGP) holds promise for personalized treatment but is currently limited by the lack of actionable mutations and predictive biomarkers.

EXPERT OPINION

A personalized, multimodal approach is essential for optimizing mRCC management. Careful patient selection is key to balancing the benefits of treatment with the risks of toxicity. While CN and metastasis-directed therapies remain useful in select cases, advancing individualized care requires the development of validated biomarkers and broader application of CGP.

Intratumoral mycobiome heterogeneity influences the tumor microenvironment and immunotherapy outcomes in renal cell carcinoma

The intratumoral mycobiome plays a crucial role in the tumor microenvironment, but its impact on renal cell carcinoma (RCC) remains unclear. We collected and quantitatively profiled the intratumoral mycobiome data from 1044 patients with RCC across four international cohorts, of which 466 patients received immunotherapy. Patients were stratified into mycobiota ecology-depauperate and mycobiota ecology-flourishing (MEF) groups based on fungal abundance. The MEF group had worse prognosis, higher fungal diversity, down-regulated lipid catabolism, and exhausted CD8+ T cells. We developed the intratumoral mycobiota signature and intratumoral mycobiota-related genes expression signature, which robustly predicted prognosis and immunotherapy outcomes in RCC and other cancers. Aspergillus tanneri was identified as a potential key fungal species influencing RCC prognosis. Our findings suggest that the intratumoral mycobiome suppresses lipid catabolism and induces T cell exhaustion in RCC.

The Role of Killer Ig-like Receptors in Diseases from A to Z

Killer Ig-like Receptors (KIRs) regulate immune responses, maintaining the balance between activation and inhibition of the immune system. KIRs are expressed on natural killer cells and some CD8 T cells and interact with HLA class I molecules, influencing various physiological and pathological processes. KIRs' polymorphism creates a variability in immune responses among individuals. KIRs are involved in autoimmune disorders, cancer, infections, neurological diseases, and other diseases. Specific combinations of KIRs and HLA are linked to several diseases' susceptibility, progression, and outcomes. In particular, the balance between inhibitory and activating KIRs can determine how the immune system responds to pathogens and tumors. An imbalance can lead to an excessive response, contributing to autoimmune diseases, or an inadequate response, allowing immune evasion by pathogens or cancer cells. The increasing number of studies on KIRs highlights their essential role as diagnostic and prognostic biomarkers and potential therapeutic targets. This review provides a comprehensive overview of the role of KIRs in all clinical conditions and diseases, listed alphabetically, where they are analyzed.

Integrated Multi-Omics Analysis Unveils Distinct Molecular Subtypes and a Robust Immune-Metabolic Prognostic Model in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is characterized by significant clinical and molecular heterogeneity, with immune and metabolic processes playing crucial roles in tumor progression and influencing patient outcomes. This study aims to elucidate the molecular subtypes of ccRCC by employing non-negative matrix factorization (NMF) clustering on differentially expressed genes (DEGs), thereby identifying distinct transcriptional profiles, immune cell infiltration patterns, and subsequent survival outcomes. Utilizing NMF clustering, we identified two molecular subtypes of ccRCC. We developed a prognostic model using LASSO-Cox regression, validated with multiple datasets and quantitative reverse transcription polymerase chain reaction (qRT-PCR), incorporating ten immunity- and metabolism-related genes (IMRGs) for overall survival (OS) prediction. Immune cell infiltration and tumor mutational burden (TMB) analyses were performed to explore differences between high- and low-risk groups, while Gene Set Enrichment Analysis (GSEA) provided insights into relevant biological pathways. The findings revealed that subtype C1, characterized by a "cold" tumor microenvironment, correlates with better prognostic outcomes compared to subtype C2, which exhibits an immunologically active environment and worse survival prospects. High-risk patients demonstrated poorer OS associated with alterations in immune and metabolic pathways. Immune checkpoint analysis indicated the upregulation of CTLA4, LAG3, and LGALS9 in high-risk patients, suggesting potential therapeutic targets. A nomogram integrating IMRG risk scores with clinical factors displayed high predictive accuracy for 1-, 3-, and 5-year OS. These findings provide novel insights into the molecular heterogeneity of ccRCC and emphasize the interconnected roles of immune dysregulation and metabolic alterations in tumor progression. By identifying key prognostic biomarkers and potential therapeutic targets, this study paves the way for innovative strategies aimed at harnessing immune and metabolic pathways for better clinical outcomes in ccRCC patients.

Chemerin in immunity

Chemerin is a distant member of the cystatin protein family, initially discovered as a chemotactic factor and subsequently also reported to act as adipokine and angiogenetic factor. The biological activity of chemerin is regulated at different levels, such as gene expression, protein processing, and interaction with both signaling and nonsignaling receptors. Chemerin is mostly produced by stromal cells, such as adipocytes, fibroblasts, and epithelial and endothelial cells, and circulates in almost all human tissues as a zymogen that needs to be proteolytically activated to exert its biological functions. At the receptor level, chemerin binds a G protein-coupled 7-transmembrane domain receptor Chemerin1 (also named ChemR23 and CMKLR1), mostly expressed by innate immune cells, such as macrophages, dendritic cells, and natural killer cells, and by border cells. In addition, chemerin may bind GPR1, a weak signaling receptor, and CCRL2, a nonsignaling receptor expressed by barrier cells, such as endothelial and epithelial cells, able to regulate leukocytes' migration by multiple mechanisms. The aim of this review is to summarize the contribution of chemerin in the regulation of immune responses.

Emerging innovative treatment strategies for advanced clear cell renal cell carcinoma

Dramatic advances in biological discoveries, since the 1990s, have continued to reshape the treatment paradigm of metastatic renal cell carcinoma (RCC). Von Hippel Lindau (VHL) gene alterations are associated with pro-angiogenic activity and are central to the pathogenesis of clear cell RCC (ccRCC), the most predominant histologic subtype of RCC. Antiangiogenic strategies revolving around this VHL/HIF/VEGF axis have been shown to improve survival in metastatic ccRCC. The discovery of immune checkpoints and agents that target their inhibition introduced a new treatment paradigm for patients with RCC. While initially approved as monotherapy, studies investigating immune checkpoint inhibitor combinations have led to their approval as the new standard of care, providing durable responses and unprecedented improvements in clinical outcome. Despite these advances, the projected 14 390 deaths in 2024 from RCC underscore the need to continue efforts in expanding and optimizing treatment options for patients with metastatic RCC. This article reviews key findings that have transformed the way we understand and treat metastatic RCC, in addition to highlighting novel treatment strategies that are currently under development.

Oncogenic TFE3 fusions drive OXPHOS and confer metabolic vulnerabilities in translocation renal cell carcinoma

Translocation renal cell carcinoma (tRCC) is an aggressive subtype of kidney cancer driven by TFE3 gene fusions, which act via poorly characterized downstream mechanisms. Here we report that TFE3 fusions transcriptionally rewire tRCCs toward oxidative phosphorylation (OXPHOS), contrasting with the highly glycolytic nature of most other renal cancers. Reliance on this TFE3 fusion-driven OXPHOS programme renders tRCCs vulnerable to NADH reductive stress, a metabolic stress induced by an imbalance of reducing equivalents. Genome-scale CRISPR screening identifies tRCC-selective vulnerabilities linked to this metabolic state, including EGLN1, which hydroxylates HIF-1α and targets it for proteolysis. Inhibition of EGLN1 compromises tRCC cell growth by stabilizing HIF-1α and promoting metabolic reprogramming away from OXPHOS, thus representing a vulnerability for OXPHOS-dependent tRCC cells. Our study defines tRCC as being dependent on a mitochondria-centred metabolic programme driven by TFE3 fusions and nominates EGLN1 inhibition as a therapeutic strategy in this cancer.

Effect of FLRT3 on epithelial-mesenchymal transition in clear cell renal cell carcinoma

OBJECTIVE

FLRT3 is a member of the fibronectin leucine-rich transmembrane protein family, which regulates cell-cell adhesion and epithelial-mesenchymal transition (EMT). However, the role of FLRT3 in clear cell renal cell carcinoma (ccRCC) remains unknown; therefore, we explored the potential role of FLRT3 in ccRCC.

METHODS

We analyzed FLRT3 expression levels in ccRCC tissues across multiple databases. We examined the relationship between FLRT3 expression and EMT through single-cell data and transcriptional regulatory network analyses. Additionally, we investigated the association between FLRT3 expression levels and various clinicopathological indicators, compared the impact of FLRT3 expression on patient prognosis, and constructed a nomogram prognostic model. Furthermore, we performed enrichment analyses on differentially expressed genes to reveal potential biological functions and mechanisms.

RESULTS

FLRT3 expression levels were significantly lower in ccRCC tissues compared to normal kidney tissues and progressively decreased with advancing pathological stages and grades. FLRT3 mediated the promotion of EMT by transcription factor ATF4; survival analysis indicated that patients with high FLRT3 expression had significantly better overall survival compared to those with low FLRT3 expression. Enrichment analysis revealed that FLRT3 was associated with epithelial cell differentiation, retinol metabolic processes, and collagen-containing extracellular matrix.

CONCLUSION

FLRT3 expression is downregulated in ccRCC and may promote EMT through transcription factor ATF4. Downregulation of FLRT3 is associated with poor prognosis.

Research progress of hypoxia-inducible factor-1α and zinc in the mechanism of diabetic kidney disease

Diabetic kidney disease is one of the common complications in diabetic patients and has gradually become an important pathogenic factor in chronic kidney disease. Therefore, studying the mechanisms of its occurrence and development is of great significance for the prevention and treatment of diabetic kidney disease. Some researchers have pointed out that there is a phenomenon of hypoxia in diabetic kidney tissue and believe that hypoxia-inducible factor-1α is closely related to the occurrence and progression of diabetic kidney disease. Additionally, the homeostasis of zinc plays a key role in the body's adaptation to hypoxic environments. However, the specific relationship among these three factors remains unclear. This article provides a detailed review of the multiple roles of hypoxia-inducible factor-1α in the pathogenesis of diabetic kidney disease, including: regulating angiogenesis, increasing the expression of erythropoietin, modulating oxidative stress through the PI3K/AKT and HIF-1α/HO-1 pathways, promoting inflammatory cell infiltration and the release of inflammatory factors to induce inflammatory responses, facilitating epithelial-mesenchymal transition, pathological angiogenesis, and promoting the release of fibrotic factors, ultimately leading to renal fibrosis. Furthermore, HIF-1α also participates in the occurrence and development of diabetic kidney disease through mechanisms such as regulating apoptosis, inducing mitochondrial autophagy, and vascular calcification. At the same time, this article clarifies the regulatory role of the trace element zinc on hypoxia-inducible factor-1α in diabetic kidney disease. This article provides references and insights for further research on the pathogenesis and progression of diabetic kidney disease.

Copper Drives Remodeling of Metabolic State and Progression of Clear Cell Renal Cell Carcinoma

SIGNIFICANCE

The work establishes a requirement for glucose-dependent coordination between energy production and redox homeostasis, which is fundamental for the survival of cancer cells that accumulate Cu and contributes to tumor growth.

Targeting NAD+ Metabolism Vulnerability in FH-Deficient Hereditary Leiomyomatosis and Renal Cell Carcinoma with the Novel NAMPT Inhibitor OT-82

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an inherited cancer syndrome caused by germline pathogenic variants in the fumarate hydratase (FH) gene. Affected individuals are at risk for developing cutaneous and uterine leiomyomas and aggressive FH-deficient renal cell carcinoma (RCC) with a papillary histology. Due to a disrupted tricarboxylic acid cycle, FH-deficient kidney cancers rely on aerobic glycolysis for energy production, potentially creating compensatory metabolic vulnerabilities. This study conducted a high-throughput drug screen in HLRCC cell lines, which identified a critical dependency on nicotinamide adenine dinucleotide (NAD), a redox cofactor produced by the biosynthetic enzyme nicotinamide phosphoribosyltransferase (NAMPT). Human HLRCC tumors and HLRCC-derived cell lines exhibited elevated NAMPT expression compared with controls. FH-deficient HLRCC cells, but not FH-restored HLRCC or normal kidney cells, were sensitive to NAMPT inhibition. HLRCC cell line viability was significantly decreased in both 2D and 3D in vitro cultures in response to the clinically relevant NAMPT inhibitor OT-82. NAMPT inhibition in vitro significantly decreased the total amount of NAD+, NADH, NADP, NADPH, and poly-ADP-ribose levels, and the effects of NAMPT inhibition could be rescued by the downstream NAD precursor nicotinamide mononucleotide (NMN), confirming the on-target activity of OT-82. Moreover, NAMPT inhibition by OT-82 in two HLRCC xenograft models resulted in severely reduced tumor growth. OT-82 treatment of HLRCC xenograft tumors in vivo inhibited glycolytic flux as demonstrated by reduced lactate/pyruvate ratio in hyperpolarized 13C-pyruvate magnetic resonance spectroscopic imaging experiments. Overall, our data define NAMPT inhibition as a potential therapeutic approach for FH-deficient HLRCC-associated RCC.

The molecular code of kidney cancer: A path of discovery for gene mutation and precision therapy

Renal cell carcinoma (RCC) is a malignant tumor with highly heterogeneous and complex molecular mechanisms. Through systematic analysis of TCGA, COSMIC and other databases, 24 mutated genes closely related to RCC were screened, including VHL, PBRM1, BAP1 and SETD2, which play key roles in signaling pathway transduction, chromatin remodeling and DNA repair. The PI3K/AKT/mTOR signaling pathway is particularly important in the pathogenesis of RCC. Mutations in genes such as PIK3CA, MTOR and PTEN are closely associated with metabolic abnormalities and tumor cell proliferation. Clinically, mTOR inhibitors and VEGF-targeted drugs have shown significant efficacy in personalized therapy. Abnormal regulation of metabolic reprogramming, especially glycolysis and glutamine metabolic pathways, provides tumor cells with continuous energy supply and survival advantages, and GLS1 inhibitors have shown promising results in preclinical studies. This paper also explores the potential of immune checkpoint inhibitors in combination with other targeted drugs, as well as the promising application of nanotechnology in drug delivery and targeted therapy. In addition, unique molecular mechanisms are revealed and individualized therapeutic strategies are explored for specific subtypes such as TFE3, TFEB rearrangement type and SDHB mutant type. The review summarizes the common gene mutations in RCC and their molecular mechanisms, emphasizes their important roles in tumor diagnosis, treatment and prognosis, and looks forward to the application prospects of multi-pathway targeted therapy, metabolic targeted therapy, immunotherapy and nanotechnology in RCC treatment, providing theoretical support and clinical guidance for individualized treatment and new drug development.

Systemic therapy for non-clear cell renal cell carcinomas: A systematic review

OBJECTIVE

Renal cell carcinoma (RCC) is the most common kidney cancer, with clear cell RCC being the predominant subtype. However, non-clear cell RCC constitutes a significant proportion of cases, presenting distinct challenges in treatment due to its varied histological subtypes. Despite recent advancements, the optimal therapeutic approach for non-clear cell RCC remains uncertain due to limited high-quality evidence. This systematic review aims to evaluate the efficacy of systemic therapies in nccRCC subgroups.

DATA SOURCE

A comprehensive literature search identified studies from 2010 to 2024, using PubMed and Clinicaltrials.gov databases focusing on clinical trials and treatment outcomes.

DATA SUMMARY

Results highlight the evolving therapeutic landscape, with targeted agents and immunotherapy demonstrating promising anti-tumor effects. Notably, tyrosine kinase inhibitors (TKIs) such as sunitinib and mTOR inhibitors like temsirolimus have shown efficacy across different subtypes. Combination therapies, including immunotherapy-based regimens, have also shown favorable outcomes. immune checkpoint inhibitors such as nivolumab and pembrolizumab demonstrated encouraging antitumor activity. Furthermore, specific targeting of signaling pathways, such as the c-MET pathway, has demonstrated efficacy in certain PapillaryRCC.

CONCLUSION

While combination therapies, including immunotherapies, have shown positive outcomes, immune checkpoint inhibitors like nivolumab and pembrolizumab have demonstrated encouraging antitumor activity. Additionally, targeting the c-MET pathway has proven effective in certain papillary RCC. Further research is warranted to establish optimal treatment strategies and improve outcomes for patients with non-clear cell RCC. Systemic therapy for non-clear cell RCC is complex and evolving. Further research is needed to delineate optimal treatment strategies for different histological subtypes and improve patient outcomes.

Positive associations between dietary potential acid load and renal cancer incidence and mortality: Results from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening trial

OBJECTIVES

To explore the relationships between dietary potential acid load and renal cancer (RC) incidence and mortality.

STUDY DESIGN

A prospective cohort study involving 97,166 U S. adults aged 55-74 years.

METHODS

Data utilized in this study were drawn from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO). Dietary potential acid load was assessed by dietary acid load (DAL), potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores using a validated Diet History Questionnaire (DHQ). Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs) for RC incidence and mortality with adjustment for potential confounders. Restricted cubic spline (RCS) plots were utilized to reveal whether there were nonlinear associations between the DAL, PRAL, and NEAP scores and RC incidence and mortality.

RESULTS

During a follow-up period of 859,907 and 1,467,573 person-years, 423 RC cases and 221 mortality cases were documented. DAL, PRAL, and NEAP scores were positively associated with RC incidence (DAL: HR 1.41; 95% CI 1.05, 1.90; P-trend = 0.010; PRAL: HR 1.45; 95% CI 1.10, 1.91; P-trend = 0.010; NEAP: HR 1.39; 95% CI 1.04, 1.85; P-trend = 0.029). Similar associations were observed between DAL, PRAL, and NEAP scores and RC mortality. The RCS plots demonstrated a nonlinear association between DAL score and RC risk, while a linear association was observed between DAL score and RC mortality. Similar linear associations were found between PRAL and NEAP scores and RC incidence and mortality.

CONCLUSION

A higher dietary potential acid load was associated with higher risk of RC incidence and mortality in American adults.

HIF1α Plays a Crucial Role in the Development of TFE3-Rearranged Renal Cell Carcinoma by Orchestrating a Metabolic Shift Toward Fatty Acid Synthesis

Tumor development often requires cellular adaptation to a unique, high metabolic state; however, the molecular mechanisms that drive such metabolic changes in TFE3-rearranged renal cell carcinoma (TFE3-RCC) remain poorly understood. TFE3-RCC, a rare subtype of RCC, is defined by the formation of chimeric proteins involving the transcription factor TFE3. In this study, we analyzed cell lines and genetically engineered mice, demonstrating that the expression of the chimeric protein PRCC-TFE3 induced a hypoxia-related signature by transcriptionally upregulating HIF1α and HIF2α. The upregulation of HIF1α by PRCC-TFE3 led to increased cellular ATP production by enhancing glycolysis, which also supplied substrates for the TCA cycle while maintaining mitochondrial oxidative phosphorylation. We crossed TFE3-RCC mouse models with Hif1α and/or Hif2α knockout mice and found that Hif1α, rather than Hif2α, is essential for tumor development in vivo. RNA-seq and metabolomic analyses of the kidney tissues from these mice revealed that ketone body production is inversely correlated with tumor development, whereas de novo lipid synthesis is upregulated through the HIF1α/SREBP1-dependent mechanism in TFE3-RCC. Our data suggest that the coordinated metabolic shift via the PRCC-TFE3/HIF1α/SREBP1 axis is a key mechanism by which PRCC-TFE3 enhances cancer cell metabolism, promoting tumor development in TFE3-RCC.

Upregulation of GSTP1 mediated by chimeric TFE3 promotes TFE3-tRCC progression by targeting JNK signaling pathway

BACKGROUND

TFE3-translocation renal cell carcinoma (TFE3-tRCC), a distinct subtype of kidney cancer characterized by Xp11.2 translocations, involving TFE3 fusion with various partner genes, lacks effective treatments and prognostic biomarkers for advanced stages. This study aimed to unravel the pathogenic mechanisms and uncover novel therapeutic targets.

METHODS

The transcriptional characterization of TFE3-tRCC was conducted by RNA sequencing on 14 untreated primary TFE3-tRCC patients. The relative mRNA and protein levels were detected using qRT-PCR and Western blot, respectively. The location of ASPL-TFE3 fusion protein was analyzed by immunofluorescence. MTT and colony formation assays were used to detect cell proliferation. Annexin V/PI staining was used to evaluate cell apoptosis. Transwell assays were used to evaluate in vitro cell migration and invasion.

RESULTS

In TFE3-tRCC patients, GSTP1 expression was upregulated. ASPL-TFE3 cell models revealed that the ASPL-TFE3 fusion protein translocates to the nucleus, contributing to tumorigenesis. Notably, GSTP1 was transcriptionally activated by chimeric TFE3. Treatment with GSTP1-targeting siRNA or the GSTP1 inhibitor Ezatiostat effectively inhibited tumor growth and induced apoptosis in TFE3-tRCC cells. Furthermore, GSTP1 was found to drive TFE3-tRCC progression via modulation of the JNK signaling pathway.

CONCLUSION

Upregulation of GSTP1 mediated by chimeric TFE3 promotes TFE3-tRCC progression by targeting JNK signaling pathway, which underscore the potential of GSTP1 as a promising therapeutic target for TFE3-tRCC.

Construction and evaluation of a prognostic model for metabolism-related genes in kidney renal clear cell carcinoma using TCGA database

OBJECTIVE

To investigate the expression of metabolism-related genes (MRGs) in kidney renal clear cell carcinoma (KIRC) and their association with patient prognosis, and to identify potential targets for intervention.

METHODS

Bioinformatics methods were employed to mine the KIRC transcriptome data in The Cancer Genome Atlas Program (TCGA) database in order to identify MRGs that are aberrantly expressed in cancerous tissues. Subsequently, a prognostic risk score model was constructed and its predictive capacity was evaluated. Finally, the expression of prognostically relevant MRGs was validated using external datasets and KIRC clinical samples.

RESULTS

A total of 789 differentially expressed MRGs associated with KIRC were screened, of which 465 genes were upregulated and 324 genes were downregulated, and finally 23 genes were screened to establish a risk score model. We found that the AUCs of the risk score model for predicting patients' 1-, 3- and 5-year overall survival (OS) were 0.804, 0.766 and 0.802, respectively. These findings suggest that the model has good predictive ability. A multifactorial Cox analysis revealed that 23 MRGs risk score was significantly associated with the overall survival of KIRC patients, and could therefore be used as an independent risk factor for the prognosis of KIRC patients (HR = 3.495, P < 0.001). Meanwhile, Kaplan-Meier analyses of the high-risk and low-risk groups indicated that the high-risk group exhibited a markedly inferior overall survival (OS) prognosis. The validation of clinical samples from KIRC patients and four external data sets (GSE36895, GSE40435, GSE53757 and GSE66272) demonstrated that KCNN4 and PLK1 were highly expressed in KIRC, whereas TEK, PLG, ANGPTL3, TFAP2A, ANK3, ATP1A1 and UCN exhibited low expression in KIRC.

CONCLUSION

Several MRGs are aberrantly expressed in KIRC, from which we screened 23 genes and constructed a MRGs prognostic risk model that can effectively predict the prognosis of KIRC patients and provide a new foundation for personalised diagnosis and treatment of KIRC.

Extrajunctional CLDN10 cooperates with LAT1 and accelerates clear cell renal cell carcinoma progression

BACKGROUND & AIMS

In addition to their adhesive properties, cell adhesion molecules such as claudins (CLDNs) exhibit signaling ability to organize diverse cellular events. Although the CLDN-adhesion signaling stimulates or inhibits cancer progression, the underlying mechanism remains poorly established. Here, we verified whether and how CLDN10 promotes intracellular signals and malignant phenotypes in clear cell renal cell carcinoma (ccRCC).

METHODS

We developed a novel monoclonal antibody that specifically recognizes CLDN10. By immunohistochemistry using this antibody, the clinicopathological significance of aberrant CLDN10 expression in 165 ccRCC patients was determined. We next generated the ccRCC cells (786-O, ACHN, and OS-RC-2) expressing CLDN10, and compared their phenotypes with those of control cells. Immunoprecipitation-mass spectrometry was used to identify a CLDN10-interacting protein, followed by evaluation of its association with CLDN10 and loss-of-functions in ccRCC cells.

RESULTS

High CLDN10 expression predicted poor outcome in ccRCC patients and represented an independent prognostic marker for cancer-specific survival. Cell surface CLDN10 promoted cell viability, proliferation, and migration of ccRCC cells, as well as their tumor growth. CLDN10 also activated mTOR signaling and expression of downstream targets, including MYC target genes. Notably, we found that CLDN10 forms a complex with an amino acid transporter, LAT1, and that CLDN10-LAT1 signaling facilitates malignant phenotypes in ccRCC cells. Structural prediction and immunoprecipitation analysis results strongly suggest an interaction between CLDN10-TM1 (transmembrane domain 1) and LAT1-TM4.

CONCLUSIONS

We conclude that CLDN10-LAT1 signaling drives ccRCC progression. Taken together with our previous findings on CLDN-Src-family kinases signaling, CLDNs propagate distinct intracellular signals depending on their association with different binding partners.

m6Am Methyltransferase PCIF1 Promotes LPP3 Mediated Phosphatidic Acid Metabolism and Renal Cell Carcinoma Progression

N6-methyl-2'-O-methyladenosine (m6Am), occurring adjacent to the 7-methylguanosine (m7G) cap structure and catalyzed by the newly identified writer PCIF1 (phosphorylated CTD interacting factor 1), has been implicated in the pathogenesis of various diseases. However, its involvement in renal cell carcinoma (RCC) remains unexplored. Here, significant upregulation of PCIF1 and m6Am levels in RCC tissues are identified, unveiling their oncogenic roles both in vitro and in vivo. Mechanically, employing m6Am-Exo-Seq, LPP3 (phospholipid phosphatase 3) mRNA is identified as a key downstream target whose translation is enhanced by m6Am modification. Furthermore, LPP3 is revealed as a key regulator of phosphatidic acid metabolism, critical for preventing its accumulation in mitochondria and facilitating mitochondrial fission. Consequently, Inhibition of the PCIF1/LPP3 axis significantly altered mitochondrial morphology and reduced RCC tumor progression. In addition, depletion of PCIF1 sensitizes RCC to sunitinib treatment. This study highlights the intricate interplay between m6Am modification, phosphatidic acid metabolism, and mitochondrial dynamics, offering a promising therapeutic avenue for RCC.

CT Characterization of Lipid Metabolism in Clear Cell Renal Cell Carcinoma: Relationship Between Liver Hounsfield Unit Values and Adipose Differentiation-Related Protein Gene Expression

Radiogenomics is an emerging field that links imaging features with molecular characteristics of diseases. In clear cell renal cell carcinoma (ccRCC), metabolic reprogramming leads to lipid accumulation, influenced by the adipose differentiation-related protein (ADFP). This study aimed to investigate whether hepatic and tumoral Hounsfield Unit (HU) values could serve as noninvasive radiogenomic biomarkers for ADFP expression in ccRCC. We analyzed CT images of 185 ccRCC patients, comparing lipid-associated HU values in the liver and tumor across ADFP expression statuses. Patients with low-grade ccRCC expressing ADFP showed significantly lower minimum HU values in both liver and tumor tissue, indicating greater lipid accumulation. Additionally, ADFP expression correlated negatively with abdominal adipose tissue compartments and positively with minimum tumoral HU values, linking systemic lipid metabolism to tumor biology. These findings suggest that hepatic and tumoral HU measurements may serve as noninvasive markers of lipid accumulation related to ADFP, providing insight into metabolic alterations in ccRCC. While promising, these results require validation in larger, controlled studies due to sample size and variability limitations. This approach could enhance the radiogenomic assessment of ccRCC, supporting noninvasive insights into tumor metabolism and progression.

Global trends and projections of occupational trichloroethylene (TCE) exposure-associated kidney cancer: Insights of the Global Burden of Disease (GBD) Study 2021 from 1990 to 2021 and prediction to 2050

BACKGROUND

Exposure to trichloroethylene (TCE) in occupations is associated with an increased risk of kidney cancer (KC). However, there is a lack of comprehensive study on the global burden of occupational exposure to TCE-related KC.

METHODS

Epidemiological data on occupational TCE exposure-associated KC from 1990 to 2021 were obtained from Global Burden of Disease (GBD) 2021 study, including death counts and disability-adjusted life years (DALYs). Global burden of this disease was stratified by genders, age, socio-demographic index (SDI) quintiles, GBD subcontinental regions, and countries. The estimated annual percentage change (EAPC) was calculated to illustrate trends over the last 32 years, and forecasts were conducted to predict the disease burden until 2050.

RESULTS

In 2021, the global age-standardized death rate (ASDR) of occupational TCE exposure-related KC was 0.0009 (95 %UI: 0.0002-0.0016) per 100,000 persons, and the age-standardized DALY rate (ASDAR) was 0.0284 (95 %UI: 0.0062-0.0522) per 100,000 individuals. The disease showed significant heterogeneity by sex and age, with males bearing a notably higher burden, and the burden being concentrated in the 50-79 year-old group. Major burdens were focused in middle to high-middle SDI regions, especially in Southern Latin America (Uruguay, Argentina, and Chile). Over 32 years, the burden of occupational TCE exposure-associated KC has gradually increased, with projections indicating continued growth to 2050, particularly among males and individuals aged 50-79. Regions like high-middle SDI areas, North America, High-income North America, Southern Sub-Saharan Africa, saw the most significant increases. Correlation analyses indicated a positive association between ASDR and ASDAR with SDI, while EAPC showed a notable negative correlation with SDI. Decomposition analyses reveals three global population determinants that positively contributed to the increase in deaths, but negatively impacted DALYs.

CONCLUSION

This study highlights a significant rising trend of occupational TCE exposure-associated KC from 1990 to 2021 and projected to 2050, with an emphasis on the disease burden in men, elderly population, and middle to high-middle SDI regions, underscoring the impact of occupational TCE exposure on KC.

Risk factors of surgical compliance and impact on survival in patients with kidney cancer: a population-based, propensity score matching study

BACKGROUND

To identify the impact of surgical compliance on survival in patients with kidney cancer and to explore the factors that influence surgical compliance.

METHODS

Clinical date of kidney cancer patients were identified from the SEER databases, and the patients were divided into surgical compliance group and surgical noncompliance group. Cox survival analysis and Kaplan-Meier curves were used to evaluate the effect of surgical compliance on overall survival (OS) and cancer-specific survival (CSS). A diagnostic nomogram was constructed to quantify individual differences in compliance, and receiver operating characteristics (ROC) curves and calibration curves were used to assess the accuracy of the nomogram. Propensity score matching (PSM) was performed to balance potential baseline confounding factors.

RESULTS

Of the 133,950 patients eligible for surgical resection, 2,814 (2.1%) patients did not opt for surgery ultimately. Surgical noncompliance was associated with poor prognosis. In all patients, Cox regression analysis showed that surgical noncompliance was an independent predictor for OS [before: HR = 2.490, 95% CI 2.374-2.612, p < 0.001; after: HR = 2.380, 95% CI 2.202-2.573, p < 0.001] and CSS [before: HR = 2.490, 95% CI 2.318-2.675, p < 0.001; after: HR = 2.035, 95% CI 1.813-2.285, p < 0.001] of kidney cancer patients before and after PSM. Multivariable logistic regression revealed that older age, afro-american origin, lower household income, and advanced tumor grade were associated with surgical noncompliance. The ROC and calibration curves showed that the diagnostic nomogram had high predictive accuracy.

CONCLUSION

Surgical compliance was an independent prognostic factor for OS and CSS in patients with kidney cancer, and surgical noncompliance was associated with poor survival.

Detection and Validation of Organic Metabolites in Urine for Clear Cell Renal Cell Carcinoma Diagnosis

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) comprises the majority, approximately 70-80%, of renal cancer cases and often remains asymptomatic until incidentally detected during unrelated abdominal imaging or at advanced stages. Currently, standardized screening tests for renal cancer are lacking, which presents challenges in disease management and improving patient outcomes. This study aimed to identify ccRCC-specific volatile organic compounds (VOCs) in the urine of ccRCC-positive patients and develop a urinary VOC-based diagnostic model.

METHODS

This study involved 233 pretreatment ccRCC patients and 43 healthy individuals. VOC analysis utilized stir-bar sorptive extraction coupled with thermal desorption gas chromatography/mass spectrometry (SBSE-TD-GC/MS). A ccRCC diagnostic model was established via logistic regression, trained on 163 ccRCC cases versus 31 controls, and validated with 70 ccRCC cases versus 12 controls, resulting in a ccRCC diagnostic model involving 24 VOC markers.

RESULTS

The findings demonstrated promising diagnostic efficacy, with an Area Under the Curve (AUC) of 0.94, 86% sensitivity, and 92% specificity.

CONCLUSIONS

This study highlights the feasibility of using urine as a reliable biospecimen for identifying VOC biomarkers in ccRCC. While further validation in larger cohorts is necessary, this study's capability to differentiate between ccRCC and control groups, despite sample size limitations, holds significant promise.

Molecular chaperones: Guardians of tumor suppressor stability and function

The term 'tumor suppressor' describes a widely diverse set of genes that are generally involved in the suppression of metastasis, but lead to tumorigenesis upon loss-of-function mutations. Despite the protein products of tumor suppressors exhibiting drastically different structures and functions, many share a common regulatory mechanism-they are molecular chaperone 'clients'. Clients of molecular chaperones depend on an intracellular network of chaperones and co-chaperones to maintain stability. Mutations of tumor suppressors that disrupt proper chaperoning prevent the cell from maintaining sufficient protein levels for physiological function. This review discusses the role of the molecular chaperones Hsp70 and Hsp90 in maintaining the stability and functional integrity of tumor suppressors. The contribution of cochaperones prefoldin, HOP, Aha1, p23, FNIP1/2 and Tsc1 as well as the chaperonin TRiC to tumor suppressor stability is also discussed. Genes implicated in renal cell carcinoma development-VHL, TSC1/2, and FLCN-will be used as examples to explore this concept, as well as how pathogenic mutations of tumor suppressors cause disease by disrupting protein chaperoning, maturation, and function.

Mangiferin: An effective agent against human malignancies

Mangiferin is a bioactive substance present in high concentration in mangoes and also in some other fruits. Owing to its potential as a chemopreventive and chemotherapeutic agent against several types of cancer, this unique, significant, and well-researched polyphenol has received a lot of attention recently. It possesses the ability to treat cancers, including rectal cancer, prostate cancer, ovarian cancer, leukemia, gastric cancer, liver cancer, chronic pancreatitis, and lung cancer. It can control/regulate multiple key signaling pathways, such as signal transducer and activator of transcription 3 (STAT3), second mitochondria-derived activator of caspases/direct inhibitor of apoptosis (IAP)-binding protein with low propidium iodide (pl) (Smac/DIABLO) nuclear factor kappa B (NF-κB), phosphatidylinositol 3 kinase/protein 3 kinase (PI3K/Akt), transforming growth factor beta/suppressor of mothers against decapentaplegic (TGF-β/SMAD), c-jun N-terminal kinase/p38 mitogen-activated protein kinase (JNK/p38-MAPK), and phosphor-I kappa B kinase (p-IκB), which are crucial to the development of cancers. By triggering apoptotic signals and halting the advancement of the cell cycle, it can also prevent some cancer cell types from proliferating and developing. It has been revealed that mangiferin targets a variety of adhesion molecules, cytokines, pro-inflammatory transcription factors, kinases, chemokines, growth factors, and cell-cycle proteins. By means of preventing the onset, advancement, and metastasis of cancer, these targets may mediate the chemopreventive and therapeutic effects of mangiferin. Mangiferin has confirmed potential benefits in lung, cervical, breast, brain, and prostate cancers as well as leukemia whether administered alone or in combination with recognized anticancer compounds. More clinical trials and research investigations are required to completely unleash the potential of mangiferin, which may lower the risk of cancer onset and act as a preventive and therapeutic alternative for a number of cancers.

Ferroptosis-associated genes and compounds in renal cell carcinoma

As the main type of renal cell carcinoma (RCC), clear cell RCC (ccRCC) is often associated with the deletion or mutation of the von Hippel Lindau (VHL) gene, enhancement of glucose and lipid metabolism, and heterogeneity of the tumor microenvironment. VHL alterations in RCC cells lead to the activation of hypoxia-inducible factors and their downstream target vascular endothelial growth factor, and to the reprogramming of multiple cell death pathways and metabolic weakness, including ferroptosis, which are associated with targeted therapy or immunotherapy. The changes in biological metabolites (e.g., iron and lipids) support ferroptosis as a potential therapeutic strategy for RCC, while iron metabolism and ferroptosis regulation have been examined as anti-RCC agents in numerous studies, and various ferroptosis-related molecules have been shown to be related to the metastasis and prognosis of ccRCC. For example, glutathione peroxidase 4 and glutaminase inhibitors can inhibit pyrimidine synthesis and increase reactive oxygen species levels in VHL-deficient RCC cells. In addition, the release of damage-associated molecular patterns by tumor cells undergoing ferroptosis also mediates antitumor immunity, and immune therapy can synergize with targeted therapy or radiotherapy through ferroptosis. However, Inducing ferroptosis not only suppresses cancer, but also promotes cancer development due to its potential negative effects on anti-cancer immunity. Therefore, ferroptosis and various tumor microenviroment-related molecules may co-occur during the development and treatment of RCC, and further understanding of the interactions, core targets, and related drugs of ferroptosis may provide new combination drug strategies for RCC treatment. Here we summarize the key genes and compounds on ferroptosis and RCC in order to envision future treatment strategies and to provide sufficient information for overcoming RCC resistance through ferroptosis.

Pattern of care and treatment outcomes of metastatic non-clear cell kidney cancer: a single centre experience from India

Background

Non-clear-cell renal cell carcinoma (nccRCC) refers to a rare diverse heterogeneous group of tumours; usually treated with immune check point inhibitors and or tyrosine kinase inhibitors (TKIs). Prospective large-scale data from Asian countries is limited.

Methods

This is a retrospective study of patients with metastatic nccRCC treated at Tata Medical Centre, Kolkata, India, from 2012 to 2022. Demographic profiles, histologic subtypes, treatment details, response to therapy (by response evaluation criteria in solid tumours (RECIST v1.1)) and survival status were captured from electronic medical records (EMRs) of hospitals up till May 2023. Kaplan Meier methods were estimated to assess progression-free survival (PFS) and overall survival (OS).

Results

A total of 89 consecutive patients were screened for this study, 24 were excluded due to inadequate data in EMR. 65 patients were included in the final analysis, with a median age at diagnosis of 59 years (range 20-84) of which 81% were male. Histologic subtypes comprised of 43% papillary, 31% clear cell with mixed histology, 3% sarcomatoid and 23% others including chromophobe, mucinous-tubular, spindle cell, oncocytic, medullary, poorly differentiated and rhabdoid). The most common site of metastasis was the lung 62% (n = 40) followed by non-regional nodes 32%, bone 26% and liver 14%. 15% patients presented with haematuria and 62% underwent nephrectomy prior to systemic therapy. The majority received pazopanib 46% (n = 30), chemotherapy 20% (n = 13) including bevacizumab plus erlotinib, sunitinib 15% (n = 10) or cabozantinib 14% (n = 9). Only 3(5%) patients received nivolumab plus cabozantinib combination. Response to treatment showed complete response in 1.5%, partial response in 20%, stable disease in 51% and progressive disease in 23% as per RECIST v1.1. 17 patients required dose reduction and interruption due to adverse effects and 33% (n = 22) received second-line therapy with nivolumab 18% (n = 4), axitinib and everolimus among others. After a median follow up of 44 months, the median PFS was 13 months (95%CI 7.2-18.9) and the median OS was 17 months (95%CI 12.1-22.1) for the entire cohort.

Conclusion

The overall response and survival for metastatic nccRCC was relatively better in comparison with published data, despite the limited number of patients treated with ICIs due to cost and access barriers.

DCS, a novel classifier system based on disulfidptosis reveals tumor microenvironment heterogeneity and guides frontline therapy for clear cell renal carcinoma

Background

Emerging evidence suggests that cell deaths are involved in tumorigenesis and progression, which may be treated as a novel direction of cancers. Recently, a novel type of programmed cell death, disulfidptosis, was discovered. However, the detailed biological and clinical impact of disulfidptosis and related regulators remains largely unknown.

Methods

In this work, we first enrolled pancancer datasets and performed multi-omics analysis, including gene expression, DNA methylation, copy number variation and single nucleic variation profiles. Then we deciphered the biological implication of disulfidptosis in clear cell renal cell carcinoma (ccRCC) by machine learning. Finally, a novel agent targeting at disulfidptosis in ccRCC was identified and verified.

Results

We found that disulfidptosis regulators were dysregulated among cancers, which could be explained by aberrant DNA methylation and genomic mutation events. Disulfidptosis scores were depressed among cancers and negatively correlated with epithelial mesenchymal transition. Disulfidptosis regulators could satisfactorily stratify risk subgroups in ccRCC, and a novel subtype, DCS3, owning with disulfidptosis depression, insensitivity to immune therapy and aberrant genome instability were identified and verified. Moreover, treating DCS3 with NU1025 could significantly inhibit ccRCC malignancy.

Conclusion

This work provided a better understanding of disulfidptosis in cancers and new insights into individual management based on disulfidptosis.

TFE3 fusions direct an oncogenic transcriptional program that drives OXPHOS and unveils vulnerabilities in translocation renal cell carcinoma

Translocation renal cell carcinoma (tRCC) is an aggressive subtype of kidney cancer driven by TFE3 gene fusions, which act via poorly characterized downstream mechanisms. Here we report that TFE3 fusions transcriptionally rewire tRCCs toward oxidative phosphorylation (OXPHOS), contrasting with the highly glycolytic metabolism of most other renal cancers. This TFE3 fusion-driven OXPHOS program, together with heightened glutathione levels found in renal cancers, renders tRCCs sensitive to reductive stress - a metabolic stress state induced by an imbalance of reducing equivalents. Genome-scale CRISPR screening identifies tRCC-selective vulnerabilities linked to this metabolic state, including EGLN1, which hydroxylates HIF-1α and targets it for proteolysis. Inhibition of EGLN1 compromises tRCC cell growth by stabilizing HIF-1a and promoting metabolic reprogramming away from OXPHOS, thus representing a vulnerability to OXPHOS-dependent tRCC cells. Our study defines a distinctive tRCC-essential metabolic program driven by TFE3 fusions and nominates EGLN1 inhibition as a therapeutic strategy to counteract fusion-induced metabolic rewiring.

Systematic analysis of the expression profiles and prognostic significance of the MED gene family in renal clear cell carcinoma

The mediator complex (MED) family is a contributing factor in the regulation of transcription and proliferation of cells, and is closely associated with the development of various types of cancer. However, the significance of the expression levels and prognostic value of MED genes in kidney renal clear cell carcinoma (KIRC) have rarely been reported. The present study analyzed the expression and prognostic potential of MED genes in KIRC. The Search Tool for the Retrieval of Interacting Genes/Proteins was used to construct the protein-protein interaction network (PPI), the Assistant for Clinical Bioinformatics database was used to perform correlation analysis, GEPIA 2 was utilized to draw the Kaplan-Meier plot and analyze prognostic significance and the Tumor Immune Estimation Resource was used to assess the association of MED genes with the infiltration of immune cells in patients with KIRC. A total of 30 MED genes were identified, and among these genes, 11 were selected for the creation of a prognostic gene signature based on the results of a LASSO Cox regression analysis. Furthermore, according to univariate and multivariate analyses, MED7, MED16, MED21, MED25 and MED29 may be valuable independent predictive biomarkers for the prognosis of individuals with KIRC. Furthermore, there were significant differences in the expression levels of MED7, MED21 and MED25 in KIRC among different tumor grades. Additionally, patients with KIRC with high transcription levels of MED7, MED21 and MED29 had considerably longer overall survival times. The expression levels of MED genes were also linked to the infiltration of several immune cells. Overall, MED genes may have potential significance in predicting the prognosis of patients with KIRC.

Exploring the prognostic implications of cuproptosis-associated alterations in clear cell renal cell carcinoma via in vitro experiments

This study investigated the impact of novel copper ionophores on the prognosis of clear cell renal cell carcinoma (ccRCC) and the tumor microenvironment (TME). The differential expression of 10 cuproptosis and 40 TME-pathway-related genes were measured in 531 tumor samples and 71 adjacent kidney samples in The Cancer Genome Atlas database. A risk score model was constructed with LASSO cox to predict the prognosis of ccRCC patients. Forest plot and function enrichment were used to study the biological function of the key genes in depth. The study found that the risk score model accurately predicted the prognosis of ccRCC patients. Patients with high scores had higher immune responses with a higher proportion of anti-tumor lymphocytes and a lower proportion of immunosuppressive M2-like macrophages. However, the high-score group also exhibited a higher proportion of T follicular helper cells and regulatory T cells. These results suggest that cuproptosis-based therapy may be worth further investigation for the treatment of ccRCC and TME. Subsequently, by using RNAi, we established the stable depletion models of FDX1 and PDHB in ccRCC cell lines 786-O and ACHN. Through CCK8, colony formation, and Transwell assays, we observed that the knockdown of FDX1 and PDHB could significantly reduce the capabilities of proliferation and migration in ccRCC cells. In conclusion, this study illuminates the potential effectiveness of copper ionophores in the treatment of ccRCC, with higher risk scores correlating with better TME immune responses. It sets the stage for future cuproptosis-based therapy research in ccRCC and other cancers, focusing on copper's role in TME.

N6-methyladenosine-modified ALDH9A1 modulates lipid accumulation and tumor progression in clear cell renal cell carcinoma through the NPM1/IQGAP2/AKT signaling pathway

Aldehyde dehydrogenases superfamily (ALDHs), which are ubiquitously present in various organisms with diverse subcellular localizations, play a crucial role in regulating malignant tumor progression; Nevertheless, their involvement in clear cell renal cell carcinoma (ccRCC) has not been elucidated. In this study, we performed comprehensive bioinformatics analyses on the 19 ALDHs genes, and identified ALDH9A1 as a key contributor in ccRCC. Expression patterns and clinical relevance of ALDH9A1 were determined using bioinformatics analyses, real-time PCR, western blotting, and immunohistochemistry. To explore the underlying mechanism behind the tumor suppressor role of ALDH9A1, RNA sequencing, methylated RNA immunoprecipitation, luciferase reporter assay, mass spectroscopy, immunoprecipitation, mutational studies and immunofluorescence were employed. The impact of ALDH9A1 in ccRCC progression and metabolic programming was assessed through both in vitro and in vivo. Here, this study revealed ALDH9A1 as a tumor suppressor gene in ccRCC. The fat mass and obesity associated protein (FTO) was identified as a demethylase for ALDH9A1 mRNA, resulting in its reduced stability and expression levels in ccRCC. Functional experiments demonstrated that the deficiency of ALDH9A1 in ccRCC promoted tumor proliferation, invasion, migration and lipid accumulation. Mechanistic insights illustrated that the diminished levels of ALDH9A1 resulted in the failure to sequester nucleophosmin 1 (NPM1) within cytoplasm, thereby suppressing the transcription of IQ motif containing the GTPase-activating protein 2 (IQGAP2), subsequently activating the AKT-mTOR signaling, ultimately fostering tumor progression and lipid accumulation. In conclusion, the present study highlights the robust prognostic significance of ALDH9A1 and delivers a comprehensive understanding of ALDH9A1-NPM1-IQGAP2-AKT axis in ccRCC. These findings established a solid research foundation for novel therapeutic strategies for ccRCC patients.

Identification of prognostic RNA editing profiles for clear cell renal carcinoma

Objective

Clear cell renal cell carcinoma (ccRCC) is the most common type of renal cancer and currently lacks effective biomarkers. This research aims to analyze and identify RNA editing profile associated with ccRCC prognosis through bioinformatics and in vitro experiments.

Methods

Transcriptome data and clinical information for ccRCC were retrieved from the TCGA database, and RNA editing files were obtained from the Synapse database. Prognostic models were screened, developed, and assessed using consistency index analysis and independent prognostic analysis, etc. Internal validation models were also constructed for further evaluation. Differential genes were investigated using GO, KEGG, and GSEA enrichment analyses. Furthermore, qPCR was performed to determine gene expression in human renal tubular epithelial cells HK-2 and ccRCC cells A-498, 786-O, and Caki-2.

Results

An RNA editing-based risk score, that effectively distinguishes between high and low-risk populations, has been identified. It includes CHD3| chr17:7815229, MYO19| chr17:34853704, OIP5-AS1| chr15:41590962, MRI1| chr19:13883962, GBP4| chr1:89649327, APOL1| chr22:36662830, FCF1| chr14:75203040 edited sites or genes and could serve as an independent prognostic factor for ccRCC patients. qPCR results showed significant up-regulation of CHD3, MYO19, MRI1, APOL1, and FCF1 in A-498, 786-O, and Caki-2 cells, while the expression of OIP5-AS1 and GBP4 was significantly down-regulated.

Conclusion

RNA editing site-based prognostic models are valuable in differentiating between high and low-risk populations. The seven identified RNA editing sites may be utilized as potential biomarkers for ccRCC.

Development of prognostic signatures and risk index related to lipid metabolism in ccRCC

Background

Clear cell renal cell carcinoma (ccRCC) is a metabolic disorder characterized by abnormal lipid accumulation in the cytoplasm. Lipid metabolism-related genes may have important clinical significance for prognosis prediction and individualized treatment.

Methods

We collected bulk and single-cell transcriptomic data of ccRCC and normal samples to identify key lipid metabolism-related prognostic signatures. qPCR was used to confirm the expression of signatures in cancer cell lines. Based on the identified signatures, we developed a lipid metabolism risk score (LMRS) as a risk index. We explored the potential application value of prognostic signatures and LMRS in precise treatment from multiple perspectives.

Results

Through comprehensive analysis, we identified five lipid metabolism-related prognostic signatures (ACADM, ACAT1, ECHS1, HPGD, DGKZ). We developed a risk index LMRS, which was significantly associated with poor prognosis in patients. There was a significant correlation between LMRS and the infiltration levels of multiple immune cells. Patients with high LMRS may be more likely to respond to immunotherapy. The different LMRS groups were suitable for different anticancer drug treatment regimens.

Conclusion

Prognostic signatures and LMRS we developed may be applied to the risk assessment of ccRCC patients, which may have potential guiding significance in the diagnosis and precise treatment of ccRCC patients.

Comprehensive prognostic assessment in kidney cancer: A multidimensional approach analyzing Fufang Sanling granules, genetic variants, and immune infiltration

This study delves into the potential therapeutic benefits of Fufang Sanling Granules for kidney cancer, focusing on their active components and the underlying mechanisms of their interaction with cancer-related targets. By constructing a drug-active component-target network based on eight herbs, key active compounds such as kaempferol, quercetin, and linolenic acid were identified, suggesting their pivotal roles in modulating immune responses and cellular signaling pathways relevant to cancer progression. The research further identified 51 central drug-disease genes through comprehensive bioinformatics analyses, implicating their involvement in crucial biological processes and pathways. A novel risk score model, encompassing six genes with significant prognostic value for renal cancer, was established and validated, showcasing its effectiveness in predicting patient outcomes through mutation analysis and survival studies. The model's predictive power was further confirmed by its ability to stratify patients into distinct risk groups with significant survival differences, highlighting its potential as a prognostic tool. Additionally, the study explored the relationship between gene expression within the identified black module and the risk score, uncovering significant associations with the extracellular matrix and immune infiltration patterns. This reveals the complex interplay between the tumor microenvironment and cancer progression. The integration of the risk score with clinical parameters through a nomogram significantly improved the model's predictive accuracy, offering a more comprehensive tool for predicting kidney cancer prognosis. In summary, by combining detailed molecular analyses with clinical insights, this study presents a robust framework for understanding the therapeutic potential of Fufang Sanling Granules in kidney cancer. It not only sheds light on the active components and their interactions with cancer-related genes but also introduces a reliable risk score model, paving the way for personalized treatment strategies and improved patient management in the future.

Cellular senescence and metabolic reprogramming model based on bulk/single-cell RNA sequencing reveals PTGER4 as a therapeutic target for ccRCC

Clear cell renal cell carcinoma (ccRCC) is the prevailing histological subtype of renal cell carcinoma and has unique metabolic reprogramming during its occurrence and development. Cell senescence is one of the newly identified tumor characteristics. However, there is a dearth of methodical and all-encompassing investigations regarding the correlation between the broad-ranging alterations in metabolic processes associated with aging and ccRCC. We utilized a range of analytical methodologies, such as protein‒protein interaction network analysis and least absolute shrinkage and selection operator (LASSO) regression analysis, to form and validate a risk score model known as the senescence-metabolism-related risk model (SeMRM). Our study demonstrated that SeMRM could more precisely predict the OS of ccRCC patients than the clinical prognostic markers in use. By utilizing two distinct datasets of ccRCC, ICGC-KIRC (the International Cancer Genome Consortium) and GSE29609, as well as a single-cell dataset (GSE156632) and real patient clinical information, and further confirmed the relationship between the senescence-metabolism-related risk score (SeMRS) and ccRCC patient progression. It is worth noting that patients who were classified into different subgroups based on the SeMRS exhibited notable variations in metabolic activity, immune microenvironment, immune cell type transformation, mutant landscape, and drug responsiveness. We also demonstrated that PTGER4, a key gene in SeMRM, regulated ccRCC cell proliferation, lipid levels and the cell cycle in vivo and in vitro. Together, the utilization of SeMRM has the potential to function as a dependable clinical characteristic to increase the accuracy of prognostic assessment for patients diagnosed with ccRCC, thereby facilitating the selection of suitable treatment strategies.

Investigating the causal associations between metabolic biomarkers and the risk of kidney cancer

Metabolic reprogramming plays an important role in kidney cancer. We aim to investigate the causal effect of 249 metabolic biomarkers on kidney cancer from population-based data. This study extracts data from previous genome wide association studies with large sample size. The primary endpoint is random-effect inverse variance weighted (IVW). After completing 249 times of two-sample Mendelian randomization analysis, those significant metabolites are included for further sensitivity analysis. According to a strict Bonferrion-corrected level (P < 2e-04), we only find two metabolites that are causally associated with renal cancer. They are lactate (OR:3.25, 95% CI: 1.84-5.76, P = 5.08e-05) and phospholipids to total lipids ratio in large LDL (low density lipoprotein) (OR: 0.63, 95% CI: 0.50-0.80, P = 1.39e-04). The results are stable through all the sensitivity analysis. The results emphasize the central role of lactate in kidney tumorigenesis and provide novel insights into possible mechanism how phospholipids could affect kidney tumorigenesis.

VDRA downregulate β-catenin/Smad3 and DNA damage and repair associated with improved prognosis in ccRCC patients

The clear cell renal cell carcinoma (ccRCC) spotlighted the poorest survival, while chromophobe renal cell carcinoma (chRCC) was associated with the best survival. Earlier studies corroborated vitamin D receptor (VDR) was a promising molecular for improving the prognosis of RCC. In contrast to VDRA, the one of VDR isoforms, VDRB1 (VDR isoform B1) has an N-terminal extension of 50 amino acids and is less ligand-dependent. However, the functional differences between VDRA and VDRB1, and their roles in the prognosis of ccRCC and chRCC, have not been investigated. In the present study, we uncovered that the transcripts related to vitamin D pathway and cellular calcium signaling were effectively decreased in the context of ccRCC, yet failed to exert a comparable effect within chRCC. Specially, minimally levels of VDRA wherein kidneys of patients suffering from ccRCC predict shorter survival time. In addition, the protein expressions for β-catenin/Smad3 pathway and DNA damage and repair pathways were obviously impeded in VDRA-overexpressed ccRCC cells, yet this inhibitory effect was conspicuously absent in enable VDRB1 cells. Our results provide a new idea to improve the prognosis of ccRCC via VDRA upregulation.

DCLRE1B/Apollo germline mutations associated with renal cell carcinoma impair telomere protection

Hereditary renal cell carcinoma (RCC) is caused by germline mutations in a subset of genes, including VHL, MET, FLCN, and FH. However, many familial RCC cases do not harbor mutations in the known predisposition genes. Using Whole Exome Sequencing, we identified two germline missense variants in the DCLRE1B/Apollo gene (ApolloN246I and ApolloY273H) in two unrelated families with several RCC cases. Apollo encodes an exonuclease involved in DNA Damage Response and Repair (DDRR) and telomere integrity. We characterized these two functions in the human renal epithelial cell line HKC8. The decrease or inhibition of Apollo expression sensitizes these cells to DNA interstrand crosslink damage (ICLs). HKC8 Apollo-/- cells appear defective in the DDRR and present an accumulation of telomere damage. Wild-type and mutated Apollo forms could interact with TRF2, a shelterin protein involved in telomere protection. However, only ApolloWT can rescue the telomere damage in HKC8 Apollo-/- cells. Our results strongly suggest that ApolloN246I and ApolloY273H are loss-of-function mutants that cause impaired telomere integrity and could lead to genomic instability. Altogether, our results suggest that mutations in Apollo could induce renal oncogenesis.

Identification of cuproptosis-related lncRNAs signature for predicting the prognosis in patients with kidney renal clear cell carcinoma

BACKGROUND

Kidney renal clear cell carcinoma (KIRC), with low survival rate, is the most frequent subtype of renal cell carcinoma. Recently, more and more studies indicate that cuproptosis-related genes (CRGs) and long non-coding RNAs (lncRNAs) play a vital role in the occurrence and development of many types of cancers. However, the roles of cuproptosis-related lncRNAs (CRlncRNAs) in the KIRC was uncertain.

RESULTS

In our study, CRlncRNAs were obtained by coexpression between differentially expressed and prognostic CRGs and differentially expressed and prognostic lncRNAs, and an 8-CRlncRNAs (AC007743.1, AC022915.1, AP005136.4, APCDD1L-DT, HAGLR, LINC02027, MANCR and SMARCA5-AS1) risk model was established according to least absolute shrinkage and selection operator (LASSO) and multivariate Cox regression. This risk model could differentiate immune cell infiltration, immune function and gene mutation.

CONCLUSIONS

This 8-CRlncRNAs risk model may be promising for the clinical prediction of prognoses, tumor immune, immunotherapy response and chemotherapeutic response in KIRC patients.

Identification and validation of a gap junction protein related signature for predicting the prognosis of renal clear cell carcinoma

Background

Gap junction proteins (GJPs) are a class of channel proteins that are closely related to cell communication and tumor development. The objective of this study was to screen out GJPs related prognostic signatures (GRPS) associated with clear cell renal cell carcinoma (ccRCC).

Materials and Methods

GJPs microarray data for ccRCC patients were obtained from The Gene Expression Omnibus (GEO) database, along with RNA sequencing data for tumor and paired normal tissues from The Cancer Genome Atlas (TCGA) database. In the TCGA database, least absolute shrinkage and selection Operator (LASSO) and Cox regression models were used to identify GJPs with independent prognostic effects as GRPS in ccRCC patients. According to the GRPS expression and regression coefficient from the multivariate Cox regression model, the risk score (RS) of each ccRCC patient was calculated, to construct the RS prognostic model to predict survival. Overall survival (OS) and progression-free survival (PFS) analyses; gene pan-cancer analysis; single gene survival analysis; gene joint effect analysis; functional enrichment analysis; tumor microenvironment (TME) analysis; tumor mutational burden (TMB) analysis; and drug sensitivity analysis were used to explore the biological function, mechanism of action and clinical significance of GRPS in ccRCC. Further verification of the genetic signature was performed with data from the GEO database. Finally, the cytofunctional experiments were used to verify the biological significance of GRPS associated GJPs in ccRCC cell lines.

Results

GJA5 and GJB1, which are GRPS markers of ccRCC patients, were identified through LASSO and Cox regression models. Low expression of GJA5 and GJB1 is associated with poor patient prognosis. Patients with high-RS had significantly shorter OS and PFS than patients with low-RS (p< 0.001). The risk of death for individuals with high-RS was 1.695 times greater than that for those with low-RS (HR = 1.695, 95%CI= 1.439-1.996, p< 0.001). Receiver Operating Characteristic (ROC) curve showed the great predictive power of the RS prognostic model for the survival rate of patients. The area under curve (AUC) values for predicting 1-year, 3-year and 5-year survival rates were 0.740, 0.781 and 0.771, respectively. The clinical column chart was also reliable for predicting the survival rate of patients, with AUC values of 0.859, 0.846 and 0.796 for predicting 1-year, 3-year and 5-year survival, respectively. The GRPS was associated with immune cell infiltration, the TME, the TMB, and sensitivity to chemotherapy drugs. Further in vitro experiments showed that knockdown of GJA5 or GJB1 could promote the proliferation, migration and epithelial-mesenchymal transition (EMT) and inhibit apoptosis of ccRCC cells.

Conclusion

GJA5 and GJB1 could be potential biological markers for predicting survival in patients with ccRCC.

Fumarate induces LncRNA-MIR4435-2HG to regulate glutamine metabolism remodeling and promote the development of FH-deficient renal cell carcinoma

Fumarate hydratase (FH) deficient renal cell carcinoma (RCC) is a type of tumor with definite metabolic disorder, but the mechanism of metabolic remodeling is still unclear. LncRNA was reported to closely correlate with cancer metabolism, however the biological role of LncRNA in the development of progression of FH-deficent RCC was not well studied either. FH-deficient RCC samples were collected in my hospital and used for RNA-sequencing and Mass spectrometry analysis. FH-deficient RCC cell line UOK262 and control pFH cells were used for in vitro experiments, including proliferation assay, transwell assay, western-blot, mass spectrometry and so on. PDX mouse model was used for further drug inhibition experiments in vivo. In this study, we analyzed the profiles of LncRNA and mRNA in FH-deficienct RCC samples, and we found that the LncRNA-MIR4435-2GH was specifically highly expressed in FH-deficient RCC compared with ccRCC. In vitro experiments demonstrated that MIR4435-2HG was regulated by Fumarate through histone demethylation, and the deletion of this gene could inhibit glutamine metabolism. RNA-pulldown experiments showed that MIR4435-2HG specifically binds to STAT1, which can transcriptionally activate GLS1. GLS1 inhibitor CB-839 could significantly suppress tumor growth in PDX tumor models. This study analyzed the molecular mechanism of MIR4435-2HG in regulating metabolic remodeling of FH-deficient RCC in clinical samples, cells and animal models by combining transcriptional and metabolic methods. We found that that GLS1 was a therapeutic target for this tumor, and MIR4435-2HG can be used as a drug sensitivity marker.

Copper drives remodeling of metabolic state and progression of clear cell renal cell carcinoma

Copper (Cu) is an essential trace element required for mitochondrial respiration. Late-stage clear cell renal cell carcinoma (ccRCC) accumulates Cu and allocates it to mitochondrial cytochrome c oxidase. We show that Cu drives coordinated metabolic remodeling of bioenergy, biosynthesis and redox homeostasis, promoting tumor growth and progression of ccRCC. Specifically, Cu induces TCA cycle-dependent oxidation of glucose and its utilization for glutathione biosynthesis to protect against H 2 O 2 generated during mitochondrial respiration, therefore coordinating bioenergy production with redox protection. scRNA-seq determined that ccRCC progression involves increased expression of subunits of respiratory complexes, genes in glutathione and Cu metabolism, and NRF2 targets, alongside a decrease in HIF activity, a hallmark of ccRCC. Spatial transcriptomics identified that proliferating cancer cells are embedded in clusters of cells with oxidative metabolism supporting effects of metabolic states on ccRCC progression. Our work establishes novel vulnerabilities with potential for therapeutic interventions in ccRCC. Accumulation of copper is associated with progression and relapse of ccRCC and drives tumor growth.Cu accumulation and allocation to cytochrome c oxidase (CuCOX) remodels metabolism coupling energy production and nucleotide biosynthesis with maintenance of redox homeostasis.Cu induces oxidative phosphorylation via alterations in the mitochondrial proteome and lipidome necessary for the formation of the respiratory supercomplexes. Cu stimulates glutathione biosynthesis and glutathione derived specifically from glucose is necessary for survival of Cu Hi cells. Biosynthesis of glucose-derived glutathione requires activity of glutamyl pyruvate transaminase 2, entry of glucose-derived pyruvate to mitochondria via alanine, and the glutamate exporter, SLC25A22. Glutathione derived from glucose maintains redox homeostasis in Cu-treated cells, reducing Cu-H 2 O 2 Fenton-like reaction mediated cell death. Progression of human ccRCC is associated with gene expression signature characterized by induction of ETC/OxPhos/GSH/Cu-related genes and decrease in HIF/glycolytic genes in subpopulations of cancer cells. Enhanced, concordant expression of genes related to ETC/OxPhos, GSH, and Cu characterizes metabolically active subpopulations of ccRCC cells in regions adjacent to proliferative subpopulations of ccRCC cells, implicating oxidative metabolism in supporting tumor growth.

Aggressive renal cell carcinoma with biphasic papillary and solid clear cell features harboring IDH2 (R172M) mutation

Renal cell carcinoma (RCC) is fundamentally a metabolic disease, and RCC associated with mutation of the Krebs cycle enzyme genes include fumarate hydratase-deficient and succinate dehydrogenase-deficient RCC. Most recently, the mutation of isocitrate dehydrogenase 2 (IDH2) has been suggested as the third Krebs cycle enzyme alteration to be associated with oncometabolite-induced RCC tumorigenesis. Herein, we report the second case of RCC harboring an IDH2 (R127M) mutation identified by targeted next-generation sequencing and further confirmed by reverse transcription polymerase chain reaction and Sanger sequencing. This tumor demonstrated a distinctive biphasic morphology, characterized by mixture of a clear cells solid component and an eosinophilic papillary component. These two components were intermingled and formed variably sized nodular or nested structures. Unfavorable histologic features, including infiltration into the perirenal and renal sinus adipose tissues, high nuclei grade, rhabdoid tumor cells, and focal tumor necrosis, were observed. The patient had local lymph nodes metastases at diagnosis and developed brain metastases 3 months after the surgery. This peculiar case provides further insights into RCCs harboring IDH2 mutations.

Exploring Novel Genome Instability-associated lncRNAs and their Potential Function in Pan-Renal Cell Carcinoma

OBJECTIVE

Genomic instability can drive clonal evolution, continuous modification of tumor genomes, and tumor genomic heterogeneity. The molecular mechanism of genomic instability still needs further investigation. This study aims to identify novel genome instabilityassociated lncRNAs (GI-lncRNAs) and investigate the role of genome instability in pan-Renal cell carcinoma (RCC).

MATERIALS AND METHODS

A mutator hypothesis was employed, combining the TCGA database of somatic mutation (SM) information, to identify GI-lncRNAs. Subsequently, a training cohort (n = 442) and a testing cohort (n = 439) were formed by randomly dividing all RCC patients. Based on the training cohort dataset, a multivariate Cox regression analysis lncRNAs risk model was created. Further validations were performed in the testing cohort, TCGA cohort, and different RCC subtypes. To confirm the relative expression levels of lncRNAs in HK-2, 786-O, and 769-P cells, qPCR was carried out. Functional pathway enrichment analyses were performed for further investigation.

RESULTS

A total of 170 novel GI-lncRNAs were identified. The lncRNA prognostic risk model was constructed based on LINC00460, AC073218.1, AC010789.1, and COLCA1. This risk model successfully differentiated patients into distinct risk groups with significantly different clinical outcomes. The model was further validated in multiple independent patient cohorts. Additionally, functional and pathway enrichment analyses revealed that GI-lncRNAs play a crucial role in GI. Furthermore, the assessments of immune response, drug sensitivity, and cancer stemness revealed a significant relationship between GI-lncRNAs and tumor microenvironment infiltration, mutational burden, microsatellite instability, and drug resistance.

CONCLUSIONS

In this study, we discovered four novel GI-lncRNAs and developed a novel signature that effectively predicted clinical outcomes in pan-RCC. The findings provide valuable insights for pan-RCC immunotherapy and shed light on potential underlying mechanisms.

Molecular Expression and Prognostic Implications of Krüppel-Like Factor 3 (KLF3) in Clear Cell Renal Cell Carcinoma

A major subtype of renal cancer is clear cell renal cell carcinoma (ccRCC). Krüppel-like factor 3 (KLF3) dysfunction is also revealed leading to poor prognosis in multiple cancer types. However, dysregulation and molecular dynamics of KLF3 underlying ccRCC progression still remains elusive. Here KLF3 gene and protein expressions in ccRCC were explored using data cohorts from The Cancer Genome Atlas (TCGA), Human Protein Atlas (HPA), Clinical Proteomic Tumor Analysis Consortium (CPTAC) and verified them in our patient cohort. Correlations of KLF3 expression with clinicopathological features, epigenetic modification, and immune microenvironment characteristics were further investigated. KLF3 was significantly down-regulated expressed in ccRCC tissues compared to adjacent normal controls. Adverse pathological parameters and poor prognosis were associated with lower expression of KLF3. Mechanically, KLF3 regulation was mainly attributed to CpG island methylation. KLF3-high expression subgroup was significantly enriched in cell signaling pathways most associated with EMT markers, angiogenesis, inflammatory response, apoptosis, TGF-β, degradation of ECM, G2M checkpoint, and PI3K-AKT-mTOR. Based on GDSC database, KLF3 upregulation was identified to be associated with higher sensitivities towards PI3K-Akt-mTOR pathway inhibitors such as PI-103, PIK-93, and OSI-027. In addition, patients with down-regulated KLF3 expressions were found more sensitive towards Trametinib, Cetuximab, and Erlotinib. Collectively, our findings suggest that KLF3 may act as a suitable biomarker for prognosis prediction, tumor microenvironment (TME) phenotype identification, thereby helping ccRCC patients to make better therapeutic decisions.

Case-Cohort Study of the Association between PFAS and Selected Cancers among Participants in the American Cancer Society's Cancer Prevention Study II LifeLink Cohort

BACKGROUND

Previous epidemiological studies found associations between exposure to per- and polyfluoroalkyl substances (PFAS) and some cancer types. Many studies considered highly exposed populations, so relevance to less-exposed populations can be uncertain. Additionally, many studies considered only cancer site, not histology.

OBJECTIVES

We conducted a case-cohort study within the American Cancer Society's prospective Cancer Prevention Study II (CPS-II) LifeLink cohort to examine associations between PFAS exposure and risk of selected cancers, considering histologic subtypes.

METHODS

Serum specimens were collected from cohort participants during the period 1998-2001. This study included a subcohort (500 men, 499 women) randomly selected from participants without prior cancer diagnoses at serum collection, and all participants with incident (after serum collection) first cancers of the breast (females only, n = 786 ), bladder (n = 401 ), kidney (n = 158 ), pancreas (n = 172 ), prostate (males only, n = 1,610 ) or hematologic system (n = 635 ). PFAS concentrations [perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA)] were measured in stored serum. We assessed associations between PFAS concentrations and incident cancers, by site and histologic subtype, using multivariable Cox proportional hazards models stratified by sex and controlling for age and year at blood draw, education, race/ethnicity, smoking, and alcohol use.

RESULTS

Serum PFOA concentrations were positively associated with renal cell carcinoma of the kidney among women [hazard ratio (HR) and 95% confidence interval (CI) per PFOA doubling: 1.54 (95% CI: 1.05, 2.26)] but not men. Among men, we observed a positive association between PFHxS concentrations and chronic lymphocytic leukemia/small lymphocytic lymphoma [CLL/SLL, HR and 95% CI per PFHxS doubling: 1.34 (95% CI: 1.02, 1.75)]. We observed some heterogeneity of associations by histologic subtype within sites.

DISCUSSION

This study supports the previously observed association between PFOA and renal cell carcinoma among women and suggests an association between PFHxS and CLL/SLL among men. Consideration of histologic subtypes might be important in future studies of PFAS-cancer associations. https://doi.org/10.1289/EHP13174.

Hypoxia as a potential inducer of immune tolerance, tumor plasticity and a driver of tumor mutational burden: Impact on cancer immunotherapy

In cancer patients, immune cells are often functionally compromised due to the immunosuppressive features of the tumor microenvironment (TME) which contribute to the failures in cancer therapies. Clinical and experimental evidence indicates that developing tumors adapt to the immunological environment and create a local microenvironment that impairs immune function by inducing immune tolerance and invasion. In this context, microenvironmental hypoxia, which is an established hallmark of solid tumors, significantly contributes to tumor aggressiveness and therapy resistance through the induction of tumor plasticity/heterogeneity and, more importantly, through the differentiation and expansion of immune-suppressive stromal cells. We and others have provided evidence indicating that hypoxia also drives genomic instability in cancer cells and interferes with DNA damage response and repair suggesting that hypoxia could be a potential driver of tumor mutational burden. Here, we reviewed the current knowledge on how hypoxic stress in the TME impacts tumor angiogenesis, heterogeneity, plasticity, and immune resistance, with a special interest in tumor immunogenicity and hypoxia targeting. An integrated understanding of the complexity of the effect of hypoxia on the immune and microenvironmental components could lead to the identification of better adapted and more effective combinational strategies in cancer immunotherapy. Clearly, the discovery and validation of therapeutic targets derived from the hypoxic tumor microenvironment is of major importance and the identification of critical hypoxia-associated pathways could generate targets that are undeniably attractive for combined cancer immunotherapy approaches.

Melatonin suppresses Akt/mTOR/S6K activity, induces cell apoptosis, and synergistically inhibits cell growth with sunitinib in renal carcinoma cells via reversing Warburg effect

BACKGROUND

Metabolic alteration drives renal cell carcinoma (RCC) development, while the impact of melatonin (MLT), a neurohormone secreted during darkness, on RCC cell growth and underlying mechanisms remains unclear.

METHODS

We detected concentration of metabolites through metabolomic analyses using UPLC-MS/MS, and the oxygen consumption rate was determined using the Seahorse Extracellular Flux analyzer.

RESULTS

We observed that MLT effectively inhibited RCC cell growth both in vitro and in vivo. Additionally, MLT increased ROS levels, suppressed antioxidant enzyme activity, and induced apoptosis. Furthermore, MLT treatment upregulated key TCA cycle metabolites while reducing aerobic glycolysis products, leading to higher oxygen consumption rate, ATP production, and membrane potential. Moreover, MLT treatment suppressed phosphorylation of Akt, mTOR, and p70 S6 Kinase as well as the expression of HIF-1α/VEGFA in RCC cells; these effects were reversed by NAC (ROS inhibitors). Conversely, MLT synergistically inhibited cell growth with sunitinib and counteracted the Warburg effect induced by sunitinib in RCC cells.

CONCLUSIONS

In conclusion, our results indicate that MLT treatment reverses the Warburg effect and promotes intracellular ROS production, which leads to the suppression of Akt/mTOR/S6K signaling pathway, induction of cell apoptosis, and synergistically inhibition of cell growth with sunitinib in RCC cells. Overall, this study provides new insights into the mechanisms underlying anti-tumor effect of MLT in RCC cells, and suggests that MLT might be a promising therapeutic for RCC.

Downregulation of Glycine N-Acyltransferase in Kidney Renal Clear Cell Carcinoma: A Bioinformatic-Based Screening

Clear cell renal cell carcinoma (KIRC) is the most common subtype of renal cell carcinoma (RCC). This form of cancer is characterized by resistance to traditional therapies and an increased likelihood of metastasis. A major factor contributing to the pathogenesis of KIRC is the alteration of metabolic pathways. As kidney cancer is increasingly considered a metabolic disease, there is a growing need to understand the enzymes involved in the regulation of metabolism in tumorigenic cells. In this context, our research focused on glycine N-acyltransferase (GLYAT), an enzyme known to play a role in various metabolic diseases and cancer. Here, through a bioinformatic analysis of public databases, we performed a characterization of GLYAT expression levels in KIRC cases. Our goal is to evaluate whether GLYAT could serve as a compelling candidate for an in-depth study, given its pivotal role in metabolic regulation and previously established links to other malignancies. The analysis showed a marked decrease in GLYAT expression in all stages and grades of KIRC, regardless of mutation rates, suggesting an alternative mechanism of regulation along the tumor development. Additionally, we observed a hypomethylation in the GLYAT promoter region and a negative correlation between the expression of the GLYAT and the levels of cancer-associated fibroblasts. Finally, the data show a correlation between higher levels of GLYAT expression and better patient prognosis. In conclusion, this article underscores the potential of GLYAT as a diagnostic and prognostic marker in KIRC.