MicroRNAs and altered metabolism of clear cell renal cell carcinoma: Potential role as aerobic glycolysis biomarkers

USP3 promotes clear cell renal cell carcinoma progression by stabilizing MYC and enhancing glycolysis

Clear cell renal cell carcinoma (ccRCC) is the most prevalent type of renal malignancy, and the deubiquitinase USP3 has been implicated as a critical factor in tumor biology. However, the precise mechanisms by which USP3 contributes to ccRCC progression remain unclear. This study investigates the role of USP3 in ccRCC and elucidates its underlying molecular mechanisms. Data from TCGA and GTEx databases showed elevated USP3 expression in ccRCC tissues and cell lines compared to normal renal tissues. Further analysis using qPCR and Western blot confirmed this upregulation in ccRCC cell lines. Functional assays revealed that silencing USP3 significantly impaired cell proliferation, migration, and invasion, while promoting apoptosis. Additionally, co-immunoprecipitation assays demonstrated an interaction between USP3 and MYC, with subsequent ubiquitination assays showing that USP3 regulates MYC stability. USP3 depletion also led to alterations in glycolysis-related gene expression, which could be partially reversed by MYC overexpression. These findings suggest that USP3 modulates ccRCC progression by stabilizing MYC, highlighting its potential as a therapeutic target in ccRCC treatment.

Glucose Metabolism and Tumor Microenvironment: Mechanistic Insights and Therapeutic Implications

Metabolic reprogramming in cancer cells involves changes in glucose metabolism, glutamine utilization, and lipid production, as well as promoting increased cell proliferation, survival, and immune resistance by altering the tumor microenvironment. Our study analyzes metabolic reprogramming in neoplastically transformed cells, focusing on changes in glucose metabolism, glutaminolysis, and lipid synthesis. Moreover, we discuss the therapeutic potential of targeting cancer metabolism, focusing on key enzymes involved in glycolysis, the pentose phosphate pathway, and amino acid metabolism, including lactate dehydrogenase A, hexokinase, phosphofructokinase and others. The review also highlights challenges such as metabolic heterogeneity, adaptability, and the need for personalized therapies to overcome resistance and minimize adverse effects in cancer treatment. This review underscores the significance of comprehending metabolic reprogramming in cancer cells to engineer targeted therapies, personalize treatment methodologies, and surmount challenges, including metabolic plasticity and therapeutic resistance.

Exosomes and microRNAs as mediators of the exercise

MicroRNAs (miRNAs), also known as microribonucleic acids, are small molecules found in specific tissues that are essential for maintaining proper control of genes and cellular processes. Environmental factors, such as physical exercise, can modulate miRNA expression and induce targeted changes in gene transcription. This article presents an overview of the present knowledge on the principal miRNAs influenced by physical activity in different tissues and bodily fluids. Numerous research projects have emphasized the significant impact of miRNAs on controlling biological changes brought about by physical activity. These molecules play main roles in important processes such as the growth of skeletal muscle and heart muscle cells, the creation of mitochondria, the development of the vascular system, and the regulation of metabolism. Studies have shown that physical exertion utilizes the contributions of miR-1, miR-133, miR-206, miR-208, and miR-486 to revitalize and restore skeletal muscle tissue. Moreover, detecting alterations in miRNA levels and connecting them to the specific outcomes of various exercise routines and intensities can act as indicators for physical adaptation and the reaction to physical activity in long-term diseases. Numerous studies have confirmed that extracellular vesicles (EVs) which composed of different members such as exosomes have the ability to reduce inflammation through the activation of the nuclear factor kappa B (NF-κB pathway. Furthermore, physical activity greatly affects the levels of specific miRNAs present in exosomes derived from skeletal muscle. Therefore, exosomal miRNAs target some pathways that are related to growth and development, such asWnt/β-catenin, PI3K/AKT, and insulin-like growth factor 1 (IGF1). Exercise-induced exosomes have also been identified as important mediators in promoting beneficial effects throughout the body. The aim of this review is to summarize the effect of exercise on the function of miRNAs and exosomes.

PIM1 kinase and its diverse substrate in solid tumors

The PIM kinase family, consisting of PIM1, PIM2, and PIM3, is a group of serine/threonine protein kinases crucial for cellular growth, immunoregulation, and oncogenesis. PIM1 kinase is often overexpressed in solid and hematopoietic malignancies, promoting cell survival, proliferation, migration, and senescence by activating key genes. In vitro and in vivo studies have established the oncogenic potential of PIM1 kinases. These kinases have been implicated in tumor progression, metastasis, and resistance to chemotherapy, underscoring their potential as a therapeutic target for cancer therapy. This review delves into the intricate molecular mechanisms through which PIM1 interacts with specific substrates in different tumor tissues, leading to diverse outcomes in various human cancers. Over the past decade, the inhibition of PIM1 in cancers has garnered significant attention as a potential standalone treatment. Various in vitro, in vivo, and early clinical trial data have provided support for this approach to varying extents. Novel compounds that inhibit PIM1 kinase have shown effectiveness and a favorable toxicity profile in preclinical studies. Several of these substances are now being studied in clinical trials due to their promising outcomes. This article provides a thorough examination of the PIM1 kinase pathways and the recent advancements in producing PIM1 kinase inhibitors for the treatment of cancer.

Interference with ENO2 promotes ferroptosis and inhibits glycolysis in clear cell renal cell carcinoma by regulating Hippo‑YAP1 signaling

Glycolytic enzyme enolase 2 (ENO2) is dysregulated in various cancer types. Nevertheless, the role and underlying mechanism of ENO2 in clear cell renal cell carcinoma (ccRCC) remain unclear. Therefore, the current study investigated the effect and mechanism of ENO2 in ccRCC. ENO2 expression in a ccRCC cell line was assessed using reverse transcription-quantitative PCR and western blotting. Analysis of glycolysis was performed by estimating the extracellular acidification rate, lactic acid concentration, glucose uptake and the expression of glucose transporter 1, pyruvate kinase muscle isozyme M2 and hexokinase 2. Moreover, ferroptosis was assessed by detecting the level of total iron, lipid peroxide, reactive oxygen species and the expression of ferroptosis-related protein. In addition, mitochondrial function was assessed using JC-1 staining and detection kits. The results indicated that ENO2 is expressed at high levels in ccRCC cell lines, and interference with ENO2 expression inhibits glycolysis, promotes ferroptosis and affects mitochondrial function in ccRCC cells. Further investigation demonstrated that interference with ENO2 expression affected ferroptosis levels in ccRCC cells by inhibiting the glycolysis process. Mechanistically, the present results indicated that ENO2 may affect ferroptosis, glycolysis and mitochondrial functions by regulating Hippo-yes-associated protein 1 (YAP1) signaling in ccRCC cells. In conclusion, the present study showed that ENO2 affects ferroptosis, glycolysis and mitochondrial functions in ccRCC cells by regulating Hippo-YAP1 signaling, hence demonstrating its potential as a therapeutic target in ccRCC.

Dichloroacetate for Cancer Treatment: Some Facts and Many Doubts

Rarely has a chemical elicited as much controversy as dichloroacetate (DCA). DCA was initially considered a dangerous toxic industrial waste product, then a potential treatment for lactic acidosis. However, the main controversies started in 2008 when DCA was found to have anti-cancer effects on experimental animals. These publications showed contradictory results in vivo and in vitro such that a thorough consideration of this compound's in cancer is merited. Despite 50 years of experimentation, DCA's future in therapeutics is uncertain. Without adequate clinical trials and health authorities' approval, DCA has been introduced in off-label cancer treatments in alternative medicine clinics in Canada, Germany, and other European countries. The lack of well-planned clinical trials and its use by people without medical training has discouraged consideration by the scientific community. There are few thorough clinical studies of DCA, and many publications are individual case reports. Case reports of DCA's benefits against cancer have been increasing recently. Furthermore, it has been shown that DCA synergizes with conventional treatments and other repurposable drugs. Beyond the classic DCA target, pyruvate dehydrogenase kinase, new target molecules have also been recently discovered. These findings have renewed interest in DCA. This paper explores whether existing evidence justifies further research on DCA for cancer treatment and it explores the role DCA may play in it.

hsa_circ_0003596, as a novel oncogene, regulates the malignant behavior of renal cell carcinoma by modulating glycolysis

BACKGROUND

This research was planned to analyze hsa_circ_0003596 (circCOL5A1) and glycolysis-focused mechanisms in renal cell carcinoma (RCC).

METHODS

circCOL5A1, miR-370-5p, and PRKCSH levels were determined in RCC tissues and selected cell lines by RT-qPCR and/or Western blot. RCC cells after corresponding transfection were tested by colony formation assay, EdU assay, Transwell assay, and flow cytometry to analyze cell proliferation, invasion, migration, and apoptosis. Meanwhile, glycolysis in cells was evaluated by measuring glucose consumption, lactic acid, and ATP production, as well as immunoblotting for HK2 and PKM2. In addition, circCOL5A1 knockdown was performed in animal experiments to observe tumor growth and glycolysis. Finally, the ceRNA network between circCOL5A1, miR-370-5p, and PRKCSH was studied by luciferase reporter assay and RIP experiment.

RESULTS

circCOL5A1 and PRKCSH were highly expressed and miR-370-5p was poorly expressed in RCC. circCOL5A1 knockdown depressed RCC proliferation, invasion, migration, and glycolysis, and enhanced apoptosis. circCOL5A1 competitively adsorbed miR-370-5p. Artificial upregulation of miR-370-5p saved the pro-tumor effect of circCOL5A1 on RCC cells, as evidenced by suppression of tumor malignancy and glycolysis. miR-370-5p targeted PRKCSH. PRKCSH overexpression contributed to a reversal of the anti-tumor effect of circCOL5A1 silencing. Silencing circCOL5A1 inhibited RCC tumor growth and glycolysis.

CONCLUSIONS

circCOL5A1 regulates the malignant behavior of RCC by modulating glycolysis.

ATAD2 promotes glycolysis and tumor progression in clear cell renal cell carcinoma by regulating the transcriptional activity of c-Myc

Clear cell renal cell carcinoma (ccRCC) is a common malignant tumor of the urogenital tract. Given that ccRCC is often resistant to radiotherapy and traditional chemotherapy, the clinical treatment of patients with ccRCC remains a challenge. The present study found that ATAD2 was significantly upregulated in ccRCC tissues. In vitro and in vivo experiments showed that the inhibition of ATAD2 expression mitigated the aggressive phenotype of ccRCC. ATAD2 was also associated with glycolysis in ccRCC. Interestingly, we found that ATAD2 could physically interact with c-Myc and promote the expression of its downstream target gene, thereby enhancing the Warburg effect of ccRCC. Overall, our study emphasizes the role of ATAD2 in ccRCC. The targeted expression or functional regulation of ATAD2 could be a promising method to reduce the proliferation and progression of ccRCC.

Effects of single bouts of different endurance exercises with different intensities on microRNA biomarkers with and without blood flow restriction: a three-arm, randomized crossover trial

PURPOSE

Physical activity is associated with altered levels of circulating microRNAs (ci-miRNAs). Changes in miRNA expression have great potential to modulate biological pathways of skeletal muscle hypertrophy and metabolism. This study was designed to determine whether the profile of ci-miRNAs is altered after different approaches of endurance exercise.

METHODS

Eighteen healthy volunteers (aged 24 ± 3 years) participated this three-arm, randomized-balanced crossover study. Each arm was a single bout of treadmill-based acute endurance exercise at (1) 100% of the individual anaerobic threshold (IANS), (2) at 80% of the IANS and (3) at 80% of the IANS with blood flow restriction (BFR). Load-associated outcomes (fatigue, feeling, heart rate, and exhaustion) as well as acute effects (circulating miRNA patterns and lactate) were determined.

RESULTS

All training interventions increased the lactate concentration (LC) and heart rate (HR) (p < 0.001). The high-intensity intervention (HI) resulted in a higher LC than both lower intensity protocols (p < 0.001). The low-intensity blood flow restriction (LI-BFR) protocol led to a higher HR and higher LC than the low-intensity (LI) protocol without BFR (p = 0.037 and p = 0.003). The level of miR-142-5p and miR-197-3p were up-regulated in both interventions without BFR (p < 0.05). After LI exercise, the expression of miR-342-3p was up-regulated (p = 0.038). In LI-BFR, the level of miR-342-3p and miR-424-5p was confirmed to be up-regulated (p < 0.05). Three miRNAs and LC show a significant negative correlation (miR-99a-5p, p = 0.011, r = - 0.343/miR-199a-3p, p = 0.045, r = - 0.274/miR-125b-5p, p = 0.026, r = - 0.302). Two partial correlations (intervention partialized) showed a systematic impact of the type of exercise (LI-BFR vs. HI) (miR-99a-59: r = - 0.280/miR-199a-3p: r = - 0.293).

CONCLUSION

MiRNA expression patterns differ according to type of activity. We concluded that not only the intensity of the exercise (LC) is decisive for the release of circulating miRNAs-as essential is the type of training and the oxygen supply.

Circulating microRNAs from the Molecular Mechanisms to Clinical Biomarkers: A Focus on the Clear Cell Renal Cell Carcinoma

microRNAs (miRNAs) are emerging as relevant molecules in cancer development and progression. MiRNAs add a post-transcriptional level of control to the regulation of gene expression. The deregulation of miRNA expression results in changing the molecular circuitry in which miRNAs are involved, leading to alterations of cell fate determination. In this review, we describe the miRNAs that are emerging as innovative molecular biomarkers from liquid biopsies, not only for diagnosis, but also for post-surgery management in cancer. We focus our attention on renal cell carcinoma, in particular highlighting the crucial role of circulating miRNAs in clear cell renal cell carcinoma (ccRCC) management. In addition, the functional deregulation of miRNA expression in ccRCC is also discussed, to underline the contribution of miRNAs to ccRCC development and progression, which may be relevant for the identification and design of innovative clinical strategies against this tumor.

miR-1224-3p Promotes Breast Cancer Cell Proliferation and Migration through PGM5-Mediated Aerobic Glycolysis

Metabolic reprogramming of aerobic glycolysis is a hallmark of cancer cells. Regulators of aerobic glycolysis have become targets for cancer diagnosis and therapy. However, the regulators of aerobic glycolysis in breast cancer development have not been well elucidated. Here, we show that the phosphoglucomutase (PGM) family member PGM5 promotes conversion of glucose-1-phosphate (G1P) into glucose-6-phosphate (G6P) and inhibits breast cancer cell proliferation and migration through regulating aerobic glycolysis. In breast cancer patients, PGM5 is significantly downregulated, and its low expression is a predictor of poor prognosis. MicroRNA-1224-3p (miR-1224-3p) inhibits the PGM5 level through directly targeting its 3'-untranslated region and suppresses PGM5-mediated breast cancer cell proliferation, migration, and glycolytic function. Moreover, the miR-1224-3p/PGM5 axis regulates the expression of cell cycle- and apoptosis-related genes and the markers of epithelial-mesenchymal transition (EMT), a process involved in migration and metastasis of cancer cells. Taken together, our results indicate that miR-1224-3p/PGM5 axis plays important roles in breast cancer cell proliferation, migration, and aerobic glycolysis and may be a potential target for breast cancer therapy.

A novel 10 glycolysis-related genes signature could predict overall survival for clear cell renal cell carcinoma

Background

The role of glycolysis in tumorigenesis has received increasing attention and multiple glycolysis-related genes (GRGs) have been proven to be associated with tumor metastasis. Hence, we aimed to construct a prognostic signature based on GRGs for clear cell renal cell carcinoma (ccRCC) and to explore its relationships with immune infiltration.

Methods

Clinical information and RNA-sequencing data of ccRCC were obtained from The Cancer Genome Atlas (TCGA) and ArrayExpress datasets. Key GRGs were finally selected through univariate COX, LASSO and multivariate COX regression analyses. External and internal verifications were further carried out to verify our established signature.

Results

Finally, 10 GRGs including ANKZF1, CD44, CHST6, HS6ST2, IDUA, KIF20A, NDST3, PLOD2, VCAN, FBP1 were selected out and utilized to establish a novel signature. Compared with the low-risk group, ccRCC patients in high-risk groups showed a lower overall survival (OS) rate (P = 5.548Ee-13) and its AUCs based on our established signature were all above 0.70. Univariate/multivariate Cox regression analyses further proved that this signature could serve as an independent prognostic factor (all P < 0.05). Moreover, prognostic nomograms were also created to find out the associations between the established signature, clinical factors and OS for ccRCC in both the TCGA and ArrayExpress cohorts. All results remained consistent after external and internal verification. Besides, nine out of 21 tumor-infiltrating immune cells (TIICs) were highly related to high- and low- risk ccRCC patients stratified by our established signature.

Conclusions

A novel signature based on 10 prognostic GRGs was successfully established and verified externally and internally for predicting OS of ccRCC, helping clinicians better and more intuitively predict patients’ survival.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08111-0.

Cancer Cells' Metabolism Dynamics in Renal Cell Carcinoma Patients' Outcome: Influence of GLUT-1-Related hsa-miR-144 and hsa-miR-186

Simple Summary

Renal cell carcinoma (RCC) is a metabolic associated cancer and the most common and lethal neoplasia in the adult kidney. This study aimed to understand the potential role of hsa-miR-144-5p and hsa-miR-186-3p (which target Glucose Transporter 1—GLUT-1) in clear cell RCC (ccRCC) glycolysis status, as well as their potential as biomarkers. A decrease of intracellular levels of these miRNAs and increase of their excretion was associated with an increase of GLUT-1’s levels and glycolysis’ markers. RCC patients presented higher plasmatic levels of hsa-miR-186-3p than healthy individuals and hsa-miR144-5p’s higher levels were associated with early clinical stages of RCC. Additionally, patients with low plasmatic levels of hsa-miR-144-5p and high plasmatic levels of hsa-miR-186-3p (high-risk group) showed a worse overall survival. Overall, these results indicate that circulating hsa-miR-144-5p and hsa-miR-186-3p may be potential biomarkers of ccRCC prognosis.

Abstract

The cancer cells’ metabolism is altered due to deregulation of key proteins, including glucose transporter 1 (GLUT-1), whose mRNA levels are influenced by microRNAs (miRNAs). Renal cell carcinoma (RCC) is the most common and lethal neoplasia in the adult kidney, mostly due to the lack of accurate diagnosis and follow-up biomarkers. Being a metabolic associated cancer, this study aimed to understand the hsa-miR-144-5p and hsa-miR-186-3p’s potential as biomarkers of clear cell RCC (ccRCC), establishing their role in its glycolysis status. Using three ccRCC lines, the intra- and extracellular levels of both miRNAs, GLUT-1’s mRNA expression and protein levels were assessed. Glucose consumption and lactate production were evaluated as glycolysis markers. A decrease of intracellular levels of these miRNAs and increase of their excretion was observed, associated with an increase of GLUT-1’s levels and glycolysis’ markers. Through a liquid biopsy approach, we found that RCC patients present higher plasmatic levels of hsa-miR-186-3p than healthy individuals. The Hsa-miR144-5p’s higher levels were associated with early clinical stages. When patients were stratified according to miRNAs plasmatic levels, low plasmatic levels of hsa-miR-144-5p and high plasmatic levels of hsa-miR-186-3p (high-risk group) showed the worst overall survival. Thus, circulating levels of these miRNAs may be potential biomarkers of ccRCC prognosis.

LAT1 and ASCT2 Related microRNAs as Potential New Therapeutic Agents against Colorectal Cancer Progression

The development and progression of colorectal cancer (CRC) have been associated with genetic and epigenetic alterations and more recently with changes in cell metabolism. Amino acid transporters are key players in tumor development, and it is described that tumor cells upregulate some AA transporters in order to support the increased amino acid (AA) intake to sustain the tumor additional needs for tumor growth and proliferation through the activation of several signaling pathways. LAT1 and ASCT2 are two AA transporters involved in the regulation of the mTOR pathway that has been reported as upregulated in CRC. Some attempts have been made in order to develop therapeutic approaches to target these AA transporters, however none have reached the clinical setting so far. MiRNA-based therapies have been gaining increasing attention from pharmaceutical companies and now several miRNA-based drugs are currently in clinical trials with promising results. In this review we combine a bioinformatic approach with a literature review in order to identify a miRNA profile with the potential to target both LAT1 and ASCT2 with potential to be used as a therapeutic approach against CRC.

Glycolysis-Related Genes Serve as Potential Prognostic Biomarkers in Clear Cell Renal Cell Carcinoma

Metabolic rearrangement is a marker of cancer that has been widely studied in recent years. One of the major metabolic characteristics of tumor cells is the high levels of glycolysis, even under aerobic conditions, a phenomenon that is called the "Warburg effect." We investigated the expression and copy number variation (CNV) frequency of all glycolysis-related genes in multiple cancer types and found many differentially expressed genes, particularly in clear cell renal cell carcinoma (ccRCC). Single nucleotide variants (SNVs) showed that the overall average mutation frequency for all genes was low. The purpose of this study was to establish a predictive model by studying glycolysis-related genes in ccRCC. We compared the expression of glycolysis-related genes in 539 ccRCC tissues and 72 normal renal tissues from The Cancer Genome Atlas dataset and identified 17 upregulated and 26 downregulated genes. Pathway analysis revealed that PSAT1 and SDHB could activate the cell cycle, RPIA could activate the DNA damage response, and HK3 could activate apoptosis and EMT signaling, while PDK2 could inhibit apoptosis. The results of the drug sensitivity analysis suggested that some of these differentially expressed genes were positively correlated with drug sensitivity. Thirteen genes were selected from the gene coexpression network and the LASSO regression analysis. The Kaplan-Meier overall survival curves showed that the expression of upregulated genes in ccRCC patients was associated with lower overall survival. We established a predictive model consisting of 13 genes (RPIA, G6PD, PSAT1, ENO2, HK3, IDH1, PDK4, PGM2, PGK1, FBP1, OGDH, SUCLA2, and SUCLG2). This predictive model correlated well with the development and progression of ccRCC. Thus, it is of great value in the diagnosis and prognostic evaluation of ccRCC and may aid the identification of potential prognostic biomarkers and drug targets.

Targeting glycolysis with 2-deoxy-D-glucose sensitizes primary cell cultures of renal cell carcinoma to tyrosine kinase inhibitors

PURPOSE

To investigate the synergistic effect of glycolysis inhibition on therapy answer to tyrosine kinase inhibitors in renal carcinoma.

METHODS

Primary cell cultures from 33 renal tumors including clear cell RCC (ccRCC), papillary RCC and the rare subtype chromophobe RCC as well as two metastases of ccRCC were obtained and cultivated. The patient-derived cells were verified by immunohistochemistry. CcRCC cells were further examined by exon sequencing of the von Hippel-Lindau gene (VHL) and by RNA-sequencing. Next, cell cultures of all subtypes of RCC were exposed to increasing doses of various tyrosine kinase inhibitors (axitinib, cabozantinib and pazopanib) and the glycolysis inhibitor 2-deoxy-D-glucose, alone or combined. CellTiter-Glo^® Luminescence assay and Crystal Violet staining were used to assess the inhibition of glycolysis and the viability of the cultured primary cells.

RESULTS

The cells expressed characteristic tissue markers and, in case of ccRCC cultures, the VHL status of the tumor they derived from. An upregulation of HK1, PFKP and SLC2A1 was observed, while components of the respiratory chain were downregulated, confirming a metabolic shift towards aerobic glycolysis. The tumors displayed variable individual responses for the therapeutics. All subtypes of RCC were susceptible to cabozantinib treatment indicated by decreased proliferation. Adding 2-deoxy-D-glucose to tyrosine kinase inhibitors decreased ATP production and increased the susceptibility of ccRCC to pazopanib treatment.

CONCLUSION

This study presents a valuable tool to cultivate even uncommon and rare renal cancer subtypes and allows testing of targeted therapies as a personalized approach as well as testing new therapies such as glycolysis inhibition in an in vitro model.

Extracellular Vesicles Enriched in hsa-miR-301a-3p and hsa-miR-1293 Dynamics in Clear Cell Renal Cell Carcinoma Patients: Potential Biomarkers of Metastatic Disease

Clear cell renal cell carcinoma (ccRCC) is the most aggressive subtype of kidney cancer and up to 40% of patients submitted to surgery with a curative intent will relapse. Thus, the aim of this study was to analyze the applicability of an Extracellular vesicle (EV) derived miRNA profile as potential prognosis biomarkers in ccRCC patients. We analyzed a nine-miRNA profile in plasma EVs from 32 ccRCC patients with localized disease (before and after surgery) and in 37 patients with metastatic disease. We observed that the levels of EV-derived hsa-miR-25-3p, hsa-miR-126-5p, hsa-miR-200c-3p, and hsa-miR-301a-3p decreased after surgery, whereas hsa-miR-1293 EV-levels increased. Furthermore, metastatic patients presented higher levels of hsa-miR-301a-3p and lower levels of hsa-miR-1293 when compared to patients with localized disease after surgery. Functional enrichment analysis of the targets of the four miRNAs that decreased after surgery resulted in an enrichment of terms related to cell cycle, proliferation, and metabolism, suggesting that EV-miRNA enrichment in the presence of the tumor could represent an epigenetic mechanism to sustain tumor development. Taken together, these results suggest that EVs content varies depending on the presence or absence of the disease and that an increase of EV-derived hsa-miR-301a-3p, and decrease of EV-derived hsa-miR-1293, may be potential biomarkers of metastatic ccRCC.

The microRNA miR-3174 Suppresses the Expression of ADAM15 and Inhibits the Proliferation of Patient-Derived Bladder Cancer Cells

Background

Bladder cancer is a major urinary system cancer, and its mechanism of action regarding its progression is unclear. The goal of this study was to examine the expression of ADAM panel in the clinical specimens of bladder cancer and to investigate the role of miR-3174/ADAM15 (a disintegrin and metalloprotease 15) axis in the regulation of bladder cancer cell proliferation.

Methods

The expression of an ADAM gene panel (including ADAM8, 9, 10, 11, 12, 15, 17, 19, 22, 23, 28, and 33), including 30 pairs of bladder tumor and non-tumor specimens, was examined by Ion AmpliSeq Targeted Sequencing. A microRNA (miRNA) that could potentially target the ADAM with the highest expression level in the tumor tissue was identified using the online tool miRDB. Next, the interaction between the miRNA and ADAM15 was identified by Western blot. Finally, the proliferation of bladder cancer cells was examined using MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) experiments (cell proliferation examining) and subcutaneous tumor models by using nude mice.

Results

The expression of ADAM15 in tumor tissue was found statistically significant when compared to its expression in non-tumor tissue. Additionally, ADAM15's expression in tumor tissue was found the highest of all other tested ADAMs. Next, by using the online tool miRDB, a microRNA termed miR-3174 was identified that targets ADAM15 and inhibits its expression by binding to its 3'-untranslated region. Finally, we found that overexpression of miR-3174 in bladder cancer cells inhibited the proliferation of cells due to the inhibition of ADAM15.

Conclusion

In the present work, the data highlight that miR-3174 inhibits the proliferation of bladder cancer cells by targeting ADAM15.

Overexpression of PPT2 Represses the Clear Cell Renal Cell Carcinoma Progression by Reducing Epithelial-to-mesenchymal Transition

Clear cell renal cell carcinoma (ccRCC) is one of the most common malignant tumors of the urinary system and has a poor response to radiotherapy and chemotherapy. To date, it is urgent to find effective biomarkers for the prevention and treatment of ccRCC. The occurrence and development of ccRCC is closely related to metabolic disturbances. Palmitoyl protein thioesterase 2 (PPT2) is a lysosomal thioesterase which is highly associated with metabolism, and it has never been studied in ccRCC. In this study, we first revealed PPT2 is significantly downregulated in ccRCC, and its expression level is highly correlated with clinicopathological parameters of ccRCC patients. Our ROC curve analyses evaluated the potential of PPT2 as a novel diagnostic marker and prognostic factor. Functional experiment results showed overexpression of PPT2 represses the proliferation, migration and invasion of ccRCC cells in vitro. Mechanistic investigations demonstrated that overexpression of PPT2 represses the ccRCC progression by reducing epithelial-to-mesenchymal transition (EMT). In conclusion, PPT2 is downregulated in ccRCC. Decreased PPT2 expression may be considered as a novel diagnostic marker and prognostic factor and serve as a therapeutic target for ccRCC.

A cluster of long non-coding RNAs exhibit diagnostic and prognostic values in renal cell carcinoma

Kidney cancer ranked in the top 10 for both men and women in the estimated numbers of new cancer cases in the United States in 2018. Targeted therapies have recently been administered to patients with clear cell renal cell carcinoma (ccRCC), but the overall survival of patients at the terminal stage of the disease has not been as good as expected. It is therefore necessary to uncover efficient biomarkers for early diagnosis, and to clarify the molecular mechanisms underlying ccRCC progression and metastasis. Increased evidence has shown that long non-coding RNAs (lncRNAs) play important roles during tumor progression. In this study, 10 candidate lncRNAs with diagnostic and prognostic values in ccRCC were identified: IGFL2-AS1, AC023043.1, AP000439.2, AC124854.1, AL355102.4, TMEM246-AS1, AL133467.3, ZNF582-AS1, LINC01510 and PSMG3-AS1. Enrichment analysis revealed metabolic and functional pathways, which may be closely associated with kidney cancer tumorigenesis. Six representative processes were summarized, namely glycolysis, amino acid metabolism, lipid synthesis, reductive carboxylation, nucleotide metabolism, transmembrane transport and signal transduction. In combination, the present results provided prognostic and diagnostic biomarkers for ccRCC and might pave the way for targeted intervention and molecular therapies in the future.

MicroRNA-96 is a potential tumor repressor by inhibiting NPTX2 in renal cell carcinoma

MicroRNA-96 (miR-96) is a vertebrate conserved microRNA which plays important roles in various cancers including renal cell carcinoma (RCC). However, its function and mechanism in RCC are still unclear. In this study, miR-96 was found to be downregulated in RCC based on The Cancer Genome Atlas datasets analyses, and its target genes, which predicted by TargetScan, were investigated. Among these target genes, neuronal pentraxin 2 (NPTX2) was upregulated more than 15-fold in RCC, and moreover, closely related to patient survival. To validate its targeting of NPTX2 experimentally, reverse transcription polymerase chain reaction, Western blot analysis, and dual-luciferase assays were performed, and results of these assays demonstrated that miR-96 inhibited expression of NPTX2 through a single 3'-untranslated region targeting site. Furthermore, transfection assays in RenCa and 786-O cells showed miR-96 and small interfering RNA of NPTX2 inhibited cell proliferation, migration, and invasion and overexpression of NPTX2 recovered the inhibition of miR-96. In conclusion, the present study reveals a novel regulatory mechanism of miR-96 on NPTX2 expression in RCC, and the potential of miR-96 as a RCC tumor repressor deserves further investigation.

microRNA-505 negatively regulates HMGB1 to suppress cell proliferation in renal cell carcinoma

microRNAs have been recognized to regulate a wide range of biology of renal cell carcinoma (RCC). Although miR-505 has been reported to play as a suppressor in several human tumors, the physiological function of miR-505 in RCC still remain unknown. Therefore, the role of miR-505 and relevant regulatory mechanisms were investigated in RCC in this study. Quantitative real-time polymerase chain reaction was conducted to detect the expression of miR-505 and high mobility group box 1 (HMGB1) in both RCC tissues and cell lines. Immunohistochemical staining was used to assess the correlation between HMGB1 expression and PCNA expression in RCC tissues. Subsequently, the effects of miR-505 on proliferation were determined in vitro using cell counting kit-8 proliferation assays and 5-ethynyl-2'-deoxyuridine incorporation. The molecular mechanism underlying the relevance between miR-505 and HMGB1 was confirmed by luciferase assay. Xenograft tumor formation was used to reflect the proliferative capacity of miR-505 in vivo experiments. Overall, a relatively lower miR-505 and higher HMGB1 expression in RCC specimens and cell lines were found. HMGB1 was verified as a direct target of miR-505 by luciferase assay. In vitro, overexpression of miR-505 negatively regulates HMGB1 to suppress the proliferation in Caki-1; meanwhile, knock-down of miR-505 negatively regulates HMGB1 to promote the proliferation in 769P. In addition, in vivo overexpression of miR-505 could inhibit tumor cell proliferation in RCC by xenograft tumor formation. Therefore, miR-505, as a tumor suppressor, negatively regulated HMGB1 to suppress the proliferation in RCC, and might serve as a novel therapeutic target for RCC clinical treatment.

LINC00511 promotes the malignant phenotype of clear cell renal cell carcinoma by sponging microRNA-625 and thereby increasing cyclin D1 expression

The expression pattern and detailed roles of long noncoding RNA LINC00511 in clear cell renal cell carcinoma (ccRCC) remain unknown. We measured LINC00511 expression in ccRCC. We clarified the clinical characteristics associated with LINC00511 in ccRCC. We examined the biological roles of LINC00511 in the progression of ccRCC, and we identified the potential mechanisms involved. LINC00511 was upregulated in ccRCC tissues and cell lines. High LINC00511 expression significantly correlated with TNM classification, lymph node metastasis, and short overall survival among patients with ccRCC. Additionally, LINC00511 knockdown restricted ccRCC cell proliferation, colony formation, and metastasis in vitro; accelerated cell cycle arrest at G0–G1 and apoptosis in vitro; and decreased tumor growth in vivo. Investigation of the mechanism revealed that LINC00511 directly interacted with microRNA-625 (miR-625), and the inhibitory effects of the LINC00511 knockdown on malignant characteristics were neutralized by miR-625 silencing. Furthermore, cyclin D1 (CCND1) was identified as a direct target of miR-625 in ccRCC cells. The tumor-suppressive activity of miR-625 upregulation on ccRCC cells was reversed by CCND1 reintroduction. In conclusion, LINC00511 serves as a competing endogenous RNA that regulates CCND1 expression by sponging miR-625 in ccRCC. Hence, the LINC00511/miR-625/CCND1 pathway might be a promising therapeutic target in ccRCC.

Extracellular vesicles transmitted miR-31-5p promotes sorafenib resistance by targeting MLH1 in renal cell carcinoma

Sorafenib provides survival benefits in patients with advanced renal cell carcinoma (RCC), but its use is hampered by acquired drug resistance. It is important to fully clarify the molecular mechanisms of sorafenib resistance, which can help to avoid, delay or reverse drug resistance. Extracellular vesicles (EVs) can mediate intercellular communication by delivering effector molecules between cells. Here, we studied whether EVs are involved in sorafenib resistance of RCC and its possible molecular mechanisms. Using differential centrifugation, EVs were isolated from established sorafenib-resistant RCC cells (786-0 and ACHN), and EVs derived from sorafenib-resistant cells were uptaken by sensitive parental RCC cells and thus promoted drug resistance. Elevated exogenous miR-31-5p within EVs effectively downregulated MutL homolog 1 (MLH1) expression and thus promoted sorafenib resistance in vitro. Mice experiments also confirmed that miR-31-5p could mediate drug sensitivity in vivo. In addition, low expression of MLH1 was observed in sorafenib-resistant RCC cells and upregulation of MLH1 expression restored the sensitivity of resistant cell lines to sorafenib. Finally, miR-31-5p level in circulating EVs of RCC patients with progressive disease (PD) during sorafenib therapy was higher when compared to that in the pretherapy status. In conclusion, EVs shuttled miR-31-5p can transfer resistance information from sorafenib-resistant cells to sensitive cells by directly targeting MLH1, and thus magnify the drug resistance information to the whole tumor. Furthermore, miR-31-5p and MLH1 could be promising predictive biomarkers and therapeutic targets to prevent sorafenib resistance.

Molecular Mechanisms in Clear Cell Renal Cell Carcinoma: Role of miRNAs and Hypermethylated miRNA Genes in Crucial Oncogenic Pathways and Processes

Clear cell renal cell carcinoma (ccRCC) is the third most common urological cancer, and it has the highest mortality rate. The increasing drug resistance of metastatic ccRCC has resulted in the search for new biomarkers. Epigenetic regulatory mechanisms, such as genome-wide DNA methylation and inhibition of protein translation by interaction of microRNA (miRNA) with its target messenger RNA (mRNA), are deeply involved in the pathogenesis of human cancers, including ccRCC, and may be used in its diagnosis and prognosis. Here, we review oncogenic and oncosuppressive miRNAs, their putative target genes, and the crucial pathways they are involved in. The contradictory behavior of a number of miRNAs, such as suppressive and anti-metastatic miRNAs with oncogenic potential (for example, miR-99a, miR-106a, miR-125b, miR-144, miR-203, miR-378), is examined. miRNAs that contribute mostly to important pathways and processes in ccRCC, for instance, PI3K/AKT/mTOR, Wnt-β, histone modification, and chromatin remodeling, are discussed in detail. We also separately consider their participation in crucial oncogenic processes, such as hypoxia and angiogenesis, metastasis, and epithelial-mesenchymal transition (EMT). The review also considers the interactions of long non-coding RNAs (lncRNAs) and miRNAs of significance in ccRCC. Recent advances in the understanding of the role of hypermethylated miRNA genes in ccRCC and their usefulness as biomarkers are reviewed based on our own data and those available in the literature. Finally, new data and perspectives concerning the clinical applications of miRNAs in the diagnosis, prognosis, and treatment of ccRCC are discussed.

Pim1 promotes cell proliferation and regulates glycolysis via interaction with MYC in ovarian cancer

Background

Ovarian cancer (OC) is the leading cause of death among women with gynecologic malignancies. Recent studies have highlighted the role of Pim1, which belongs to a group of constitutively activated serine/threonine kinases, in cancer development. However, the effect of Pim1 in OC is largely unclear.

Methods

OC cell lines with Pim1 overexpression or knockdown were constructed with len-tivirus transduction. Cell Counting Kit-8, colony formation, glycolysis stress test and in vivo mice models were carried out to assess the effect of Pim1 on OC biological functions. Co-immunoprecipitation assay coupled with western blot were performed to explore the intrinsic mechanisms of Pim1 in OC. Bioinformatic analysis was then performed to evaluate the expression and prognostic value of Pim1.

Results

We present the first evidence that silencing or overexpressing Pim1 can suppress or promote, respectively, OC cell proliferation. Furthermore, we demonstrated that Pim1 can significantly enhance glycolysis in OC cells. In vivo experiments further confirmed that knockdown of Pim1 inhibits the growth of tumors derived from the SKOV3 cell line. To search for the underlying molecular mechanism, we examined the effect of Pim1 on MYC, a pivotal gene in glycolysis, and observed that Pim1-mediated phosphorylation of c-Myc activated the expression of glycolysis-associated key genes such as PGK1 and LDHA. Moreover, we found that the Pim1 inhibitor SMI4a induced chemosensitization to cisplatin. Clinically, Pim1 was also overexpressed in OC and correlated with poor overall survival by bioinformatics analysis.

Conclusion

Together, these results suggest that Pim1 contributes to proliferation and gly-colysis in OC via interaction with MYC and may serve as a potential target in the treatment of OC patients.

MicroRNA regulation in blood cells of renal transplanted patients with interstitial fibrosis/tubular atrophy and antibody-mediated rejection

Interstitial fibrosis/tubular atrophy (IFTA) is associated with reduced allograft survival, whereas antibody-mediated rejection (ABMR) is the major cause for renal allograft failure. To identify specific microRNAs and their regulation involved in these processes, total RNA from blood cells of 16 kidney transplanted (KTx) patients with ABMR, stable graft function (SGF) and with T-cell mediated rejection (TCMR) was isolated. MicroRNA expression was determined by high-throughput sequencing. Differentially expressed candidate microRNAs were analyzed with RT-PCR in patients with SGF (n = 53), urinary tract infection (UTI) (n = 17), borderline rejection (BL) (n = 19), TCMR (n = 40), ABMR (n = 22) and IFTA (n = 30). From the 301 detected microRNAs, 64 were significantly regulated between the three cohorts. Selected candidate microRNAs miR-223-3p, miR-424-3p and miR-145-5p distinguished TCMR and ABMR from SGF, but not from other pathologies. Most importantly, miR-145-5p expression in IFTA patients was significantly downregulated and displayed a high diagnostic accuracy compared to SGF alone (AUC = 0.891) and compared to SGF, UTI, BL, TCMR and ABMR patients combined (AUC = 0.835), which was verified by cross-validation. The identification of miR-145-5p as IFTA specific marker in blood constitutes the basis for evaluating this potentially diagnostic microRNA as biomarker in studies including high numbers of patients and different pathologies and also the further analysis of fibrosis causing etiologies after kidney transplantation.

The role of compartmentalized signaling pathways in the control of mitochondrial activities in cancer cells

Mitochondria are the powerhouse organelles present in all eukaryotic cells. They play a fundamental role in cell respiration, survival and metabolism. Stimulation of G-protein coupled receptors (GPCRs) by dedicated ligands and consequent activation of the cAMP·PKA pathway finely couple energy production and metabolism to cell growth and survival. Compartmentalization of PKA signaling at mitochondria by A-Kinase Anchor Proteins (AKAPs) ensures efficient transduction of signals generated at the cell membrane to the organelles, controlling important aspects of mitochondrial biology. Emerging evidence implicates mitochondria as essential bioenergetic elements of cancer cells that promote and support tumor growth and metastasis. In this context, mitochondria provide the building blocks for cellular organelles, cytoskeleton and membranes, and supply all the metabolic needs for the expansion and dissemination of actively replicating cancer cells. Functional interference with mitochondrial activity deeply impacts on cancer cell survival and proliferation. Therefore, mitochondria represent valuable targets of novel therapeutic approaches for the treatment of cancer patients. Understanding the biology of mitochondria, uncovering the molecular mechanisms regulating mitochondrial activity andmapping the relevant metabolic and signaling networks operating in cancer cells will undoubtly contribute to create a molecular platform to be used for the treatment of proliferative disorders. Here, we will highlight the emerging roles of signaling pathways acting downstream to GPCRs and their intersection with the ubiquitin proteasome system in the control of mitochondrial activity in different aspects of cancer cell biology.

Molecular Characterization of Renal Cell Carcinoma: A Potential Three-MicroRNA Prognostic Signature

Background: Aberrantly expressed miRNAs promote renal cell carcinoma (RCC) growth and metastasis and are potentially useful biomarkers for metastatic disease. However, a consensus clinically significant miRNA signature has not been identified. To identify an miRNA signature for predicting clinical outcome in RCC patients, we used a four-pronged interconnected approach.Methods: Differentially expressed miRNAs were identified and analyzed in 113 specimens (normal kidney: 59; tumor: 54). miRNA profiling was performed in matched normal and tumor specimens from 8 patients and extended to 32 specimens. Seven aberrantly expressed miRNAs were analyzed by qPCR, and their levels were correlated with RCC subtypes and clinical outcome. miRNA signature was confirmed in The Cancer Genome Atlas RCC dataset (n = 241).Results: Discovery phase identified miR-21, miR-142-3p, miR-142-5p, miR-150, and miR-155 as significantly upregulated (2-4-fold) and miR-192 and miR-194 as downregulated (3-60-fold) in RCC; miR-155 distinguished small tumors (<4 cm) from benign oncocytomas. In univariate and multivariate analyses, miRNA combinations (miR-21+194; miR-21+142-5p+194) significantly predicted metastasis and/or disease-specific mortality; miR-21+142-5p+194 (for metastasis): P = 0.0017; OR, 0.53; 95% confidence interval (CI), 0.75-0.33; 86.7% sensitivity; 82% specificity. In the TCGA dataset, combined biomarkers associated with metastasis and overall survival (miR-21+142-5p+194: P < 0.0001; OR, 0.37; 95% CI, 0.58-0.23).Conclusions: The interconnected discovery-validation approach identified a three-miRNA signature as a potential predictor of disease outcome in RCC patients.Impact: With 10% survival at 5 years, metastatic disease presents poor prognosis for RCC patients. The three-miRNA signature discovered and validated may potentially at an early stage detect and predict metastasis, to allow early intervention for improving patient prognosis. Cancer Epidemiol Biomarkers Prev; 27(4); 464-72. ©2018 AACR.