Steroid receptor coactivator-3 regulates glucose metabolism in bladder cancer cells through coactivation of hypoxia inducible factor 1α

Transcriptional Regulation of De Novo Lipogenesis by SIX1 in Liver Cancer Cells

De novo lipogenesis (DNL), a hallmark of cancer, facilitates tumor growth and metastasis. Therapeutic drugs targeting DNL are being developed. However, how DNL is directly regulated in cancer remains largely unknown. Here, transcription factor sine oculis homeobox 1 (SIX1) is shown to directly increase the expression of DNL-related genes, including ATP citrate lyase (ACLY), fatty acid synthase (FASN), and stearoyl-CoA desaturase 1 (SCD1), via histone acetyltransferases amplified in breast cancer 1 (AIB1) and lysine acetyltransferase 7 （HBO1/KAT7）, thus promoting lipogenesis. SIX1 expression is regulated by insulin/lncRNA DGUOK-AS1/microRNA-145-5p axis, which also modulates DNL-related gene expression as well as DNL. The DGUOK-AS1/microRNA-145-5p/SIX1 axis regulates liver cancer cell proliferation, invasion, and metastasis in vitro and in vivo. In patients with liver cancer, SIX1 expression is positively correlated with DGUOK-AS1 and SCD1 expression and is negatively correlated with microRNA-145-5p expression. DGUOK-AS1 is a good predictor of prognosis. Thus, the DGUOK-AS1/microRNA-145-5p/SIX1 axis strongly links DNL to tumor growth and metastasis and may become an avenue for liver cancer therapeutic intervention.

Bufalin-Loaded Multifunctional Photothermal Nanoparticles Inhibit the Anaerobic Glycolysis by Targeting SRC-3/HIF-1α Pathway for Improved Mild Photothermal Therapy in CRC

Purpose

Compared with traditional photothermal therapy (PTT, >50°C), mild PTT (≤45°C) is a promising strategy for tumor therapy with fewer adverse effects. Unfortunately, its anti-tumor efficacy is hampered by thermoresistance induced by overexpression of heat shock proteins (HSPs). In our previous study, we found bufalin (BU) is a glycolysis inhibitor that depletes HSPs, which is expected to overcome thermotolerance of tumor cells. In this study, BU-loaded multifunctional nanoparticles (NPs) were developed for enhancing the mild PTT of colorectal cancer (CRC).

Methods

Fe3O4 NPs coated with the polydopamine (PDA) shell modified with polyethylene glycol (PEG) and cyclic arginine-glycyl-aspartic peptide (cRGD) for loading BU (Fe3O4@PDA-PEG-cRGD/BU NPs) were developed. The thermal variations in Fe3O4@PDA-PEG-cRGD/BU NPs solution under different conditions were measured. Glycolysis inhibition was evaluated by measuring the glucose uptake, extracellular lactate, and intracellular adenosine triphosphate (ATP) levels. The cellular cytotoxicity of Fe3O4@PDA-PEG-cRGD/BU NPs was analyzed using a cell counting kit-8 assay, Calcein-AM/PI double staining, and flow cytometry in HCT116 cells. The magnetic resonance imaging (MRI) performance and anti-tumor therapeutic efficacy of Fe3O4@PDA-PEG-cRGD/BU NPs were evaluated in HCT116-tumor bearing mice.

Results

Fe3O4@PDA-PEG-cRGD/BU NPs had an average diameter of 260.4±3.5 nm, the zeta potential of -23.8±1.6 mV, the drug loading rate of 1.1%, which had good thermal stability, photothermal conversion efficiencies and MRI performance. In addition, the released BU not only killed tumor cells but also interfered with glycolysis by targeting the steroid receptor coactivator 3 (SRC-3)/HIF-1α pathway, preventing intracellular ATP synthesis, and combating HSP-dependent tumor thermoresistance, ultimately strengthening the thermal sensitivity toward mild PTT both in vitro and in vivo.

Conclusion

This study provides a highly effective strategy for enhancing the therapeutic effects of mild PTT toward tumors.

Mesenchymal stem cell-derived exosomes overexpressing SRC-3 protect mice from cerebral ischemia by inhibiting ferroptosis

BACKGROUND

The treatment for cerebral ischemia remains limited, and new therapeutic strategies are urgently needed. Exosome has shown great promise for the treatment of cerebral ischemia. Steroid receptor coactivator-3 (SRC-3) was reported to be involved in neurological performances. In this study, we aimed to investigate the protective effects of mesenchymal stem cell (MSC)-derived exosomes overexpressing SRC-3 on cerebral ischemia in mice.

METHODS

The mice were treated with an intracerebroventricular injection of GFP-overexpressed exosomes (GFP-exo) and SRC-3-overexpressed exosomes (SRC3-exo) in a middle cerebral artery occlusion (MCAO) model of cerebral ischemia.

RESULTS

The results showed that SRC3-exo treatment significantly inhibited lipid peroxidation and ferroptosis of the neurons subjected to oxygen-glucose deprivation. It further suppressed the activation of microglia and astrocytes, and decreased the production of pro-inflammatory cytokines in the brains of MCAO mice. Furthermore, SRC3-exo treatment reduced the water content of brain tissue and infarct size, which alleviated the neurological damage and improved neurological performances in the MCAO mice.

CONCLUSIONS

Our results suggest that MSC-derived exosomes expressing SRC3 can be a therapeutic strategy for cerebral ischemia by inhibiting ferroptosis.

Membrane-associated RING-CH 7 inhibits stem-like capacities of bladder cancer cells by interacting with nucleotide-binding oligomerization domain containing 1

BACKGROUND

Cancer stem-like capacities are major factors contributing to unfavorable prognosis. However, the associated molecular mechanisms underlying cancer stem-like cells (CSCs) maintain remain unclear. This study aimed to investigate the role of the ubiquitin E3 ligase membrane-associated RING-CH 7 (MARCH7) in bladder cancer cell CSCs.

METHODS

Male BALB/c nude mice aged 4-5 weeks were utilized to generate bladder xenograft model. The expression levels of MARCHs were checked in online databases and our collected bladder tumors by quantitative real-time PCR (q-PCR) and immunohistochemistry (IHC). Next, we evaluated the stem-like capacities of bladder cancer cells with knockdown or overexpression of MARCH7 by assessing their spheroid-forming ability and spheroid size. Additionally, we conducted proliferation, colony formation, and transwell assays to validate the effects of MARCH7 on bladder cancer CSCs. The detailed molecular mechanism of MARCH7/NOD1 was validated by immunoprecipitation, dual luciferase, and in vitro ubiquitination assays. Co-immunoprecipitation experiments revealed that nucleotide-binding oligomerization domain-containing 1 (NOD1) is a substrate of MARCH7.

RESULTS

We found that MARCH7 interacts with NOD1, leading to the ubiquitin-proteasome degradation of NOD1. Furthermore, our data suggest that NOD1 significantly enhances stem-like capacities such as proliferation and invasion abilities. The overexpressed MARCH7 counteracts the effects of NOD1 on bladder cancer CSCs in both in vivo and in vitro models.

CONCLUSION

Our findings indicate that MARCH7 functions as a tumor suppressor and inhibits the stem-like capacities of bladder tumor cells by promoting the ubiquitin-proteasome degradation of NOD1. Targeting the MARCH7/NOD1 pathway could be a promising therapeutic strategy for bladder cancer patients.

Let-7a-5p abrogates progression of papillary thyroid carcinoma cells by decreasing nuclear receptor subfamily 6 group a member 1-mediated lipogenesis

Increasing evidence shows that microRNAs (miRNAs) contribute vital roles in papillary thyroid carcinoma (PTC) carcinogenesis, proliferation, invasion, and so on. As the most common endocrine malignancy, there still have largely unknown molecular events. First, our analysis and open access database information indicates that the downregulation of let-7a-5p accelerates PTC progression. Next, lentivirus mediates the overexpression of let-7a-5p PTC cells, and found let-7a-5p suppressed cancer cells proliferation and invasion. Interestingly, bioinformatics analysis hints NR6A1 is the potential target gene of let-7a-5p. The regulation was validated by luciferase and quantitative reverse transcription polymerase chain reaction (qRT-PCR) in PTC tissue and the clinic tumors. Moreover, let-7a-5p regulated NR6A1 involved in PTC cells lipogensis in vitro and in vivo. Finally, let-7a-5p abrogates PCT xenograft tumors growth, NR6A1 expression and lipogenesis. Taken together, our data indicates that let-7a-5p suppresses PCT progression through decreased lipogenesis, the related let-7a-5p/NR6A1axis might be promising candidate targets for PTC treatment.

Transcriptional co-activators: emerging roles in signaling pathways and potential therapeutic targets for diseases

Specific cell states in metazoans are established by the symphony of gene expression programs that necessitate intricate synergic interactions between transcription factors and the co-activators. Deregulation of these regulatory molecules is associated with cell state transitions, which in turn is accountable for diverse maladies, including developmental disorders, metabolic disorders, and most significantly, cancer. A decade back most transcription factors, the key enablers of disease development, were historically viewed as 'undruggable'; however, in the intervening years, a wealth of literature validated that they can be targeted indirectly through transcriptional co-activators, their confederates in various physiological and molecular processes. These co-activators, along with transcription factors, have the ability to initiate and modulate transcription of diverse genes necessary for normal physiological functions, whereby, deregulation of such interactions may foster tissue-specific disease phenotype. Hence, it is essential to analyze how these co-activators modulate specific multilateral processes in coordination with other factors. The proposed review attempts to elaborate an in-depth account of the transcription co-activators, their involvement in transcription regulation, and context-specific contributions to pathophysiological conditions. This review also addresses an issue that has not been dealt with in a comprehensive manner and hopes to direct attention towards future research that will encompass patient-friendly therapeutic strategies, where drugs targeting co-activators will have enhanced benefits and reduced side effects. Additional insights into currently available therapeutic interventions and the associated constraints will eventually reveal multitudes of advanced therapeutic targets aiming for disease amelioration and good patient prognosis.

Second generation androgen receptor antagonist, TQB3720 abrogates prostate cancer growth via AR/GPX4 axis activated ferroptosis

Purpose: Prostate cancer (PCa) poses a great threat to humans. The study aimed to evaluate the potential of TQB3720 in promoting ferroptosis to suppress prostate cancer, providing a theoretical basis for PCa therapy. Methods: PCa cells and nude mice models were divided into TQB3720, enzalutamide (ENZ), and control groups. Sulforhodamine B assay, colony formation assessment, organoids culture system, and the CCK8 assay were used for detecting proliferation. Western blot assay was processed to detect the expression of androgen receptor (AR), ferroptosis, and apoptosis-related genes. Flow cytometry was applied to measure the intracellular ROS levels. ELISA was performed to determine the cellular oxidized glutathione (GSSG) and malondialdehyde (MDA) levels. RT-qPCR was conducted to detect the mRNA expression of genes in AR signaling. BODIPYTM™ 581/591 was processed for detection of intracellular lipid peroxidation levels. The interaction of AR with other translational factor complex proteins was explored using Co-immunoprecipitation (Co-IP), and the chromatin immunoprecipitation (ChIP) assay was performed to detect the binding of AR-involved translational complex to downstream genes promoter. Luciferase reporter assay was conducted to examine the translation activity of GPX4 promoter, and immunohistochemistry (IHC) was conducted to analyze the levels of c-MYC, Ki-67 and AR in TQB3720-treated cancer tissues. Results: Here, we found TQB3720 inhibits the growth of prostate cancer in vitro and in vivo. TQB3720 treatment induced intracellular levels of GSSG and MDA significantly, by which hints AR antagonist caused ferroptosis-related cell death. Moreover, molecular evidence shown TQB3720 regulates downstream of AR signaling by binding AR resulting in inhibition of AR entry into the nucleus. Additional, we also proved that TQB3720 abrogates the interaction between AR and SP1 and leads to decrease GPX4 transcription. Conclusion: TQB3720 promotes ferroptosis in prostate cancer cells by reducing the AR/SP1 transcriptional complex binding to GPX4 promoter. As a result, it is suggested to be a potential drug for clinic prostate cancer treatment.

IMP4 Silencing Inhibits the Malignancy of Lung Adenocarcinoma via ERK Pathway

Our study aimed to elucidate the function of IMP U3 small nucleolar ribonucleoprotein 4 (IMP4) in lung adenocarcinoma (LUAD) and its potential molecular mechanisms. Cell counting kit-8, 5-ethynyl-20-deoxyuridine, flow cytometry, wound healing, and transwell assays were performed to examine the biological behaviour of LUAD cells. mRNA and protein expression levels were determined using quantitative real-time PCR, Western blotting, and immunohistochemistry. In addition, a mouse tumour xenograft model was used to evaluate the role of IMP4 in tumour progression. Furthermore, glycolysis-related indicators were measured. The levels of IMP4 were up-regulated in both human LUAD tissues and cells. IMP4 silencing significantly suppressed proliferation, migration, invasion, and glycolysis; promoted apoptosis; and induced cell cycle arrest in LUAD cells. IMP4 silencing also inactivated the extracellular signal-regulated kinase (ERK) pathway. Moreover, rescue experiments demonstrated that the function of LUAD cells induced by IMP4 overexpression could be reversed by treatment with an ERK pathway inhibitor (SCH772984). In vivo experiments further verified that IMP4 silencing repressed the growth of subcutaneous tumours and glycolysis. IMP4 silencing suppressed the malignancy of LUAD by inactivating ERK signalling.

Identification of hexosamine biosynthesis pathway as a novel prognostic signature and its correlation with immune infiltration in bladder cancer

Background: Urinary bladder cancer (UBC) is one of the common urological malignancies, lacking reliable biomarkers to predict clinical outcomes in UBC patients. Thus, it is needed to identify the novel diagnostic/prognostic biomarkers to stratify the high-risk UBC patients. As a shunt pathway of glycolysis, the hexosamine biosynthesis pathway (HBP) has been implicated in carcinogenesis. However, its prognostic value in UBC remains unclear.

Methods: The RNA sequencing and mRNA microarray datasets were downloaded from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus databases. The expression levels of five HBP genes were analyzed in normal and UBC samples, and their associations with stage, grade and survival were plotted. The performance of HBP risk group was evaluated by receiver-operating characteristics (ROC) curve. The HBP signature was generated by Gene Set Variation Analysis (GSVA) and its association with clinicopathological parameters and survival were analyzed. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were carried out to examine the potential biological functions of HBP using DAVID online tool. The infiltration estimation fraction of immune cells was performed using CIBERSORT-ABS algorithm. Gene set enrichment analysis (GSEA) was used to explore the potential function of HBP in tumor immunoregulation.

Results: Four HBP genes were upregulated in UBCs compared to normal tissues in TCGA-BLCA dataset. The upregulation of all five HBP genes was significantly associated with tumor grade and stage of UBC in three independent UBC datasets. The expression of HBP genes predicted poor clinical outcomes in UBC patients in both TCGA-BLCA and GSE13507 datasets. The high-risk group based on HBP genes showed a poor prognosis. Furthermore, HBP signature was positively associated with tumor grade and stage in TCGA-BLCA dataset and with tumor grade, stage, distal metastasis and poor survival in GSE13507 dataset. Interestingly, high-HBP signature group exhibited a high infiltration of immune cells, particularly the macrophage population.

Conclusion: We identified that HBP was a promising prognostic biomarker in UBC patients and strongly associated with immune infiltration.

Bufalin exacerbates Photodynamic therapy of colorectal cancer by targeting SRC-3/HIF-1α pathway

Photodynamic therapy (PDT) induces tumour cell death by producing reactive oxygen species (ROS), and hypoxia is one of the main factors that limits its efficiency. In our previous study, bufalin (BU) enhanced photosensitizer mTHPC-mediated PDT therapy in colorectal cancer (CRC) cells, but its mechanism was not elucidated. To explore a strategy for improving the efficacy of PDT, we designed iRGD-modified nanoparticles to co-capsuled mTHPC and BU for simultaneous delivery to the tumour site and explored the underlying mechanism of the synergistic anti-CRC effect. In our study, mTHPC&BU@VES-CSO/TPGS-RGD nanoparticles (T-B@NP) had a particle size of 148.3 ± 2.5 nm and a zeta potential of 22.8 ± 2.0 mV. Specifically, these nanoparticles passively accumulated in tumour cells, and under laser irradiation, mTHPC induced cell apoptosis and death. In addition, the sustained release of BU inhibited HIF-1α and reduced VEGF-mediated angiogenesis by targeting the SRC-3/HIF-1α pathway, which induced a strong PDT effect against CRC. In vivo studies demonstrated that codelivery of the nanoparticles under laser irradiation exhibited a superior antitumour effect (84.2%) and significantly prolonged survival time of mice, with the mechanisms of alleviating hypoxia and inhibiting angiogenesis. In summary, mTHPC and BU codelivery via nanoparticles efficiently enhances the therapeutic effects of PDT by inhibiting the SRC-3/HIF-1α pathway in CRC. This work provides an effective strategy to combat hypoxia-induced tumour resistance and overcome the barriers of PDT treatment.

α-Hederin inhibits the growth of lung cancer A549 cells in vitro and in vivo by decreasing SIRT6 dependent glycolysis

CONTEXT

α-Hederin, a potent bioactive compound of Pulsatilla chinensis (Bunge) Regel (Ranunculaceae), has many pharmacological uses, but its effect on cancer cell metabolism is still unclear.

OBJECTIVE

To elucidate the role of α-hederin in the glucose metabolism of lung cancer cells.

MATERIALS AND METHODS

Cell Counting Kit 8 and colony formation assays were employed to assess the antiproliferative effects of α-hederin. Glucose uptake, ATP generation, and lactate production were measured. Glycolysis-related proteins were detected using western blotting, and a sirtuin 6 (SIRT6) inhibitor was used to verify A549 cell proliferation. Sixty male BALB/c nude mice were divided into normal control, 5-FU (25 mg/kg), and α-hederin (5 and 10 mg/kg) groups to assess the antitumor effect for 32 days. Glycolysis-related protein expression was evaluated using immunohistochemical analysis.

RESULTS

α-Hederin inhibited A549 (IC₅₀ = 13.75 μM), NCI-H460 (IC₅₀ = 17.57 μM), and NCI-H292 (IC₅₀ = 18.04 μM) proliferation; inhibited glucose uptake and ATP generation; and reduced lactate production. Furthermore, α-hederin (10 and 15 μM) markedly inhibited hexokinase 2, glucose transporter 1, pyruvate kinase M2, lactate dehydrogenase A, monocarboxylate transporter, c-Myc, hypoxia-inducible factor-1α, and activated SIRT6 protein expression. Using a SIRT6 inhibitor, we demonstrated that α-hederin inhibits glycolysis by activating SIRT6. A tumour xenograft mouse model of lung cancer confirmed that α-hederin (5 and 10 mg/kg) inhibits lung cancer growth by inhibiting glycolysis in vivo.

DISCUSSION AND CONCLUSIONS

α-Hederin inhibits A549 cell growth by inhibiting SIRT6-dependent glycolysis. α-Hederin might serve as a potential agent to suppress cancer.

SRC-3 Knockout Attenuates Myocardial Injury Induced by Chronic Intermittent Hypoxia in Mice

This study investigated the effects of chronic intermittent hypoxia (CIH), a model of sleep apnea syndrome (SAS), on cardiac function. SRC-3 was extremely lowly expressed in the adult mouse heart tissue, while SRC-3 was highly expressed in the adult mouse heart tissue after CIH, suggesting that SRC-3 is involved in CIH model. We further studied the role of SRC-3 in CIH-induced myocardial injury in mice. Twenty-four healthy Balb/c male mice (n = 16, wild type; n = 8, SRC-3 knockout (SRC3-KO)) were randomly divided into three groups: air control (Ctrl), CIH, and CIH+SRC3-KO. Mice were exposed to CIH for 12 weeks. qRT-PCR was used to evaluate cardiac expression of the following genes: 11HSD1, 11HSD2, GR, MR, COX-2, OPN, NOX2, HIF-1-α, IL-1β, IL-6, iNOS, TNF-α, PC-1, and TGF-β. Enzymatic levels of SOD, CAT, MDA, NOS, and NO in the mouse hearts were determined using commercially available kits. Immunohistochemistry (IHC) was used to evaluate NF-κB expression in cardiac tissues. A transmission electron microscope (TEM) was used to evaluate myocardial ultrastructure. TUNEL staining was used to assess myocardial cell apoptosis. CIH induced cardiac damage, which was ameliorated in the SRC-3 KO mice. CIH significantly increased the heart-to-body weight ratio, expression of all aforementioned genes except 11HSD1, GR, and MR, and increased the levels of MDA, NOS, NO, and NF-κB, which were attenuated in the SRC-3 KO mice. The CIH group had the lowest SOD and CAT levels, which were partially recovered in the CIH+SRC3-KO group. 11HSD2 gene expression was elevated in both the CIH and CIH+SRC3-KO groups compared to the Ctrl group. The CIH group had severe myocardial cell apoptosis and mitochondrial dysfunction, which were alleviated in the CIH+SRC3-KO group. CIH causes cardiac damage through inducing oxidative stress and inflammation. Knockout of SRC-3 ameliorates CIH-induced cardiac damage through antagonizing CIH-triggered molecular changes in cardiac tissue.

Myosin 1b promotes migration, invasion and glycolysis in cervical cancer via ERK/HIF-1α pathway

BACKGROUND

Increasing evidence indicated that metabolic reprograming is essential and has been regarded as a hallmark of cancer. Although the biological functions of Myosin 1b (Myo1b) have been reported in several malignancies, the correlation between Myo1b and cancer metabolism, and its underlying mechanisms remain elusive, particularly in cervical cancer (CC).

METHODS

Myo1b and other glycolytic enzymes expression levels were examined in CC cells and tumor tissues from xenograft models by quantitative real-time PCR, Western blot and immunohistochemistry. The biological impacts and regulatory mechanisms of Myo1b on cell migration, invasion and glycolysis were explored. Also, the effects of Myo1b on carcinogenesis and metastasis in nude mice were investigated.

RESULTS

Upregulation of Myo1b was found in CC tissues and associated with poor prognosis. Overexpressed Myo1b not only significantly elevated CC cell glycolysis, migration and invasion in vitro, but also promoted tumorigenesis and metastasis in vivo. Conversely, Myo1b knockdown had opposite consequences. Moreover, our study suggested that Myo1b stimulated ERK/HIF-1α pathway and its downstream glycolysis associated genes to modulate the glycolysis, migration and invasion of CC.

CONCLUSION

These findings provide evidence that Myo1b regulates migration, invasion and glycolysis in CC through ERK/HIF-1α pathway, suggesting a promising remedial target in treatment of CC.

Circular RNA Circ-0003006 Promotes Hepatocellular Carcinoma Proliferation and Metastasis Through Sponging miR-542-3p and Regulating HIF-1A

Introduction

Hepatocellular carcinoma (HCC) is one most common cancer types among gastrointestinal cancer over the world, while its underlying mechanisms remain unclear. CircRNA has been revealed to participate in multiple biological functions and contribute to various diseases’ progression.

Methods

Bioinformatic analysis of the differently expressed circRNAs in the HCC tissues, then verified by real-time quantitative PCR (RT-qPCR) assay. We found that circ-0003006 was upregulated in the HCC tissues, the cell fractionation assay and RNA fluorescence in situ hybridization (FISH) were performed to confirm the cell location of circ-0003006. shRNA silence assay was used to knock down the expression of circ-0003006 in the HCC cells.

Results

Cell account kit 8 (CCK-8) and transwell assay were revealed that circ-0003006 knockdown inhibited the proliferation and metastasis in HCC cells. The target miR‑542‑3p and target gene HIF-1A were predicted by bioinformatics analysis, then verified through biotinylated RNA pull-down and dual-luciferase reporter assays. The mechanism, circ-0003006, probably acted as a sponge of miR‑542‑3p and regulated HIF-1A levels in hepatocellular carcinoma cells. Moreover, HIF-1A overexpression abolished the effect of circ-0003006 inhibition on the progression of hepatocellular carcinoma cells. The subcutaneous tumor formation experiment indicated that circ-0003006 knockdown inhibited the HCC cell growth in vivo.

Conclusion

Circ-0003006 was demonstrated to promote HCC progression in vitro and in vivo by sponging miR‑542‑3p to release the inhibition on HIF-1A.

Current Development and Application of Anaerobic Glycolytic Enzymes in Urothelial Cancer

Urothelial cancer is a malignant tumor with metastatic ability and high mortality. Malignant tumors of the urinary system include upper tract urothelial cancer and bladder cancer. In addition to typical genetic alterations and epigenetic modifications, metabolism-related events also occur in urothelial cancer. This metabolic reprogramming includes aberrant expression levels of genes, metabolites, and associated networks and pathways. In this review, we summarize the dysfunctions of glycolytic enzymes in urothelial cancer and discuss the relevant phenotype and signal transduction. Moreover, we describe potential prognostic factors and risks to the survival of clinical cancer patients. More importantly, based on several available databases, we explore relationships between glycolytic enzymes and genetic changes or drug responses in urothelial cancer cells. Current advances in glycolysis-based inhibitors and their combinations are also discussed. Combining all of the evidence, we indicate their potential value for further research in basic science and clinical applications.

SRC-3, a Steroid Receptor Coactivator: Implication in Cancer

Steroid receptor coactivator-3 (SRC-3), also known as amplified in breast cancer 1 (AIB1), is a member of the SRC family. SRC-3 regulates not only the transcriptional activity of nuclear receptors but also many other transcription factors. Besides the essential role of SRC-3 in physiological functions, it also acts as an oncogene to promote multiple aspects of cancer. This review updates the important progress of SRC-3 in carcinogenesis and summarizes its mode of action, which provides clues for cancer therapy.

Monoamine Oxidase A Inhibits Lung Adenocarcinoma Cell Proliferation by Abrogating Aerobic Glycolysis

Lung adenocarcinoma (LUAD) accounts for ~30% of all lung cancers and is one of the causes of cancer-related death worldwide. As the role of monoamine oxidase A (MAOA) in LUAD remains unclear, in this study, we examine how MAOA affects LUAD cell proliferation. Analyses of both public data and our data reveal that the expression of MAOA is downregulated in LUAD compared with non-tumor tissue. In addition, the expression of MAOA in tumors correlates with clinicopathologic features, and the expression of MAOA serves as an independent biomarker in LUAD. In addition, the overexpression of MAOA inhibits LUAD cell proliferation by inducing G1 arrest in vitro. Further mechanistic studies show that MAOA abrogates aerobic glycolysis in LUAD cells by decreasing hexokinase 2 (HK2). Finally, the expression of HK2 shows a negative correlation with MAOA in LUAD, and high HK2 predicts poor clinical outcome. In conclusion, our findings indicate that MAOA functions as a tumor suppressor in LUAD. Our results indicate that the MAOA/HK2 axis could be potential targets in LUAD therapy.

[Long non-coding RNA UPK1A-AS1 promotes glycolysis in hepatocellular carcinoma cells via stabilization of HIF-1α]

OBJECTIVE

To investigate the effect of long non-coding RNA UPK1A-AS1 on glycolysis of hepatocellular carcinoma cells and its underlying molecular mechanisms.

OBJECTIVE

A hepatocellular carcinoma (HCC) cell line with lentivirus-mediated stable UPK1A-AS1 overexpression and the cells infected with a negative control lentiviral vector were cultured under normoxic (21% O₂) or hypoxic (1% O₂) conditions for 24 h. The effect of UPK1A-AS1 overexpression on glycolysis of the HCC cells was examined. The expressions of glycolysis-related genes HIF1A, GLUT1, HK1, HK2 and PGK1 were detected by qRTPCR, and the effect of UPK1A-AS1 overexpression on HRE activity was detected by dual luciferase report assay. The HCC cells were treated with cycloheximide to detect the effect of UPK1A-AS1 overexpression on the stability of HIF-1α protein. Immunoprecipitation assay was used to analyze the changes in ubiquitin modification of HIF-1α protein in response to UPK1A-AS1 overexpression. The effects of UPK1A-AS1 overexpression and RNA interference of HIF-1α expression on glucose consumption, lactate production and expressions of HRE activity and glycolysis-related genes (HK1, HK2 and PGK1) were examined in the HCC cells.

OBJECTIVE

Compared with the control group, overexpression of UPK1A-AS1 significantly promoted glucose consumption and lactate production in HCC cells under both normoxic and hypoxic conditions (P < 0.05). Overexpression of UPK1A-AS1 significantly increased the expression of glycolysis-related genes including HIF1A, GLUT1, HK1, HK2 and PGK1. Upregulation of UPK1A-AS1 obviously promoted the transcriptional activity of HRE (P < 0.05). Western blotting showed that UPK1A-AS1 overexpression obviously increased the stability of HIF-1α protein and significantly reduced ubiquitin modification of HIF-1α. Downregulation of HIF-1α obviously reversed the effect of UPK1A-AS1 overexpression in promoting glucose consumption, lactate production and HRE luciferase activity. Silencing HIF-1α also suppressed the upregulation of glycolysis-related gene expressions induced by UPK1A-AS1 overexpression (P < 0.05).

OBJECTIVE

The long noncoding RNA UPK1A-AS1 upregulates the expression of glycolysis-related genes by stabilizing the expression of HIF-1α, thereby promoting glycolysis level in HCC cells.

Deoxypodophyllotoxin Inhibits Non-Small Cell Lung Cancer Cell Growth by Reducing HIF-1α-Mediated Glycolysis

Cancer cell proliferation is a metabolically demanding process that requires high rate of glycolysis to support anabolic growth. Deoxypodophyllotoxin (DPT) is a natural flavonolignan with various pharmacological activities, including antitumor effect. However, whether DPT affects the metabolic reprogramming of cancer cells is unknown. The purpose of this study is to investigate the role of DPT on non-small cell lung cancer (NSCLC) and to explore whether HIF-1α-mediated glycolysis is involved in its mechanism of action.The level of HIF-1α mRNA and protein in NSCLC cells following DPT treatment was detected using qRT-PCR and western blotting, respectively. Cell Counting Kit-8 (CCK-8) and caspase-3 activity assays were performed to analyze cell proliferation and apoptosis. The underlying molecular mechanism was identified by dual luciferase assay, Western blotting, qRT-PCR, glucose consumption, lactate production, and immunoprecipitation. A murine NSCLC model was used to clarify the effect of DPT treatment on tumor cell proliferation. Our findings showed that DPT treatment inhibited NSCLC cell growth in a dose- and time-dependent manner. Further analysis suggested that DPT treatment inhibited HIF-1α signaling pathway by Parkin-mediated protein degradation in NSCLC cells. DPT treatment significantly decreased glucose consumption and lactate production. In addition, DPT treatment reduced the expression of HIF-1α target genes, including GLUT1, HK2 and LDHA, resulting in reduction in glycolysis. We further revealed that DPT-induced cell growth inhibition and increased glucose and lactate levels could be reversed by overexpressing HIF-1α. Additionally, we found that DPT repressed NSCLC growth and GLUT1, HK2 and LDHA expression in vivo. Overall, this study suggested that DPT inhibited NSCLC growth by preventing HIF-1α-mediated glycolysis.

Role of Bladder Cancer Metabolic Reprogramming in the Effectiveness of Immunotherapy

Metabolic reprogramming (MR) is an upregulation of biosynthetic and bioenergetic pathways to satisfy increased energy and metabolic building block demands of tumors. This includes glycolytic activity, which deprives the tumor microenvironment (TME) of nutrients while increasing extracellular lactic acid. This inhibits cytotoxic immune activity either via direct metabolic competition between cancer cells and cytotoxic host cells or by the production of immune-suppressive metabolites such as lactate or kynurenine. Since immunotherapy is a major treatment option in patients with metastatic urothelial carcinoma (UC), MR may have profound implications for the success of such therapy. Here, we review how MR impacts host immune response to UC and the impact on immunotherapy response (including checkpoint inhibitors, adaptive T cell therapy, T cell activation, antigen presentation, and changes in the tumor microenvironment). Articles were identified by literature searches on the keywords or references to "UC" and "MR". We found several promising therapeutic approaches emerging from preclinical models that can circumvent suppressive MR effects on the immune system. A select summary of active clinical trials is provided with examples of possible options to enhance the effectiveness of immunotherapy. In conclusion, the literature suggests manipulating the MR is feasible and may improve immunotherapy effectiveness in UC.

LncRNA DHRS4-AS1 Inhibits the Stemness of NSCLC Cells by Sponging miR-224-3p and Upregulating TP53 and TET1

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death. This study aimed to examine the roles of DHRS4-AS1/miR-224-3p signaling in the cancer cell stemness of NSCLC. Real-time PCR showed that DHRS4-AS1 was downregulated in cancerous tissues, and bioinformatics analysis revealed that high DHRS4-AS1 expression indicated a good prognosis for NSCLC patients. Sphere and colony formation assays showed that DHRS4-AS1 overexpression significantly suppressed NSCLC cell colony formation and stem cell-like properties. DHRS4-AS1 also abrogated the expression of OCT4, SOX2, CD34, and CD133, markedly inhibited the expression of epithelial-mesenchymal transition (EMT)-related factors, N-cadherin, ZEB1, and Vimentin, and increased E-cadherin expression in spheres. Furthermore, luciferase reporter assays and real-time PCR analysis demonstrated that DHRS4-AS1 and miR-224-3p were antagonistically repressed in NSCLC cells. RNA immunoprecipitation (RIP) analysis revealed that DHRS4-AS1 interacted with miR-224-3p. DHRS4-AS1 partially reversed the miR-224-3p-decreased TP53 and TET1, resulting in the inhibition of tumor growth in vivo. Finally, TP53 and TET1 were antagonistically regulated by DHRS4-AS1 and miR-224-3p in NSCLC cells. In conclusion, TP53- and TET1-associated DHRS4-AS1/miR-224-3p axis is an essential mechanism by which NSCLC modulates cancer cell stemness.

Targeting the NCOA3-SP1-TERT axis for tumor growth in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has a high mortality rate and lacks an effective therapeutic target. Elevated expression of human telomerase reverse transcriptase (TERT) is an important hallmark in cancers, but the mechanism by which TERT is activated differentially in cancers is poorly understood. Here, we have identified nuclear receptor coactivator-3 (NCOA3) as a new modulator of TERT expression and tumor growth in HCC. NACO3 specifically binds to the TERT promoter at the -234 to -144 region and transcriptionally activates TERT expression. NCOA3 promotes HCC cell growth and tumor progression in vitro and in vivo through upregulating the TERT signaling. Knockdown of NACO3 suppresses HCC cell viability and colony formation, whereas TERT overexpression rescues this suppression. NCOA3 interacts with and recruits SP1 binding on the TERT promoter. Knockdown of NCOA3 also inhibits the expression of the Wnt signaling-related genes but has no effect on the Notch signaling-targeting genes. Moreover, NCOA3 is positively correlated with TERT expression in HCC tumor tissues, and high expression of both NCOA3 and TERT predicts a poor prognosis in HCC patients. Our findings indicate that targeting the NCOA3-SP1-TERT signaling axis may benefit HCC patients.

Histone methyltransferase SETD1A interacts with HIF1α to enhance glycolysis and promote cancer progression in gastric cancer

Growing tumors alter their metabolic profiles to support the increased cell proliferation. SETD1A, a histone lysine methyltransferase which specifically methylates H3K4, plays important roles in both normal cell and cancer cell functions. However, the function of SETD1A in gastric cancer (GC) progression and its role in GC metabolic reprogramming are still largely unknown. In the current study, we discovered that the expression of SETD1A was higher in GC tumor specimens compared to surrounding nontumor tissues. Upregulation of SETD1A increased GC cell proliferation, whereas downregulation of SETD1A inhibited GC cell proliferation. Furthermore, knockdown of SETD1A reduced glucose uptake and production of lactate and suppressed glycolysis by decreasing the expression of glycolytic genes, including GLUT1, HK2, PFK2, PKM2, LDHA, and MCT4. Mechanistically, SETD1A interacted with HIF1α to strengthen its transactivation, indicating that SETD1A promotes glycolysis through coactivation of HIF1α. SETD1A and HIF1α were recruited to the promoter of HK2 and PFK2, where SETD1A could methylate H3K4. However, knockdown of SETD1A decreased the methylation of H3K4 on HK2 and PFK2 promoter and reduced HIF1α recruitment necessary to promote transcription of glycolytic genes. Inhibition of HIF1α decelerated SETD1A‐enhanced GC cell growth. In additional, there was a linear correlation between SETD1A and several key glycolytic genes in human GC specimens obtained from TCGA dataset. Thus, our results demonstrated that SETD1A interacted with HIF1α to promote glycolysis and accelerate GC progression, implicating that SETD1A may be a potential molecular target for GC treatment.

Inhibition of histone demethylase JMJD1C attenuates cardiac hypertrophy and fibrosis induced by angiotensin II

Pathological cardiac hypertrophy is a major risk factor for cardiovascular morbidity and mortality. Histone demethylases (KDMs) are emerging regulators of transcriptional reprograming in cancer, however, their potential role in abnormal heart growth and fibrosis remains largely unknown. The aim of this current study was to examine the role of JMJD1C, an H3K9me2 specific demethylase, in angiotensin II (Ang II) induced cardiac hypertrophy and fibrosis. In this study, we observed that Ang II could increase the expression of JMJD1C detected by Western blot and RT-qPCR in vitro and in vivo. Immunofluorescence staining showed that the treatment of Ang II could increase cardiomyocyte size. RT-qPCR results have shown that Ang II could increase the expression of cell hypertrophic and fibrotic markers in H9c2 cells. Whereas, inhibition of JMJD1C by shRNA and JIB-04, a small molecule histone demethylase inhibitor, significantly reduced Ang II-induced cell hypertrophy, and hypertrophic and fibrotic marker overexpression. Furthermore, cardiomyocyte JMJD1C knockdown decreased Tissue Inhibitor of Metalloproteinases 1 (TIMP1) transcription with pro-fibrotic activity. In conclusion, JMJD1C plays an important role in Ang II-induced cardiac hypertrophy and fibrosis by activating TIMP1 transcription, targeting of JMJD1C may be an effective strategy for the treatment of Ang II-associated cardiac diseases.

Competitive glucose metabolism as a target to boost bladder cancer immunotherapy

Bladder cancer - the tenth most frequent cancer worldwide - has a heterogeneous natural history and clinical behaviour. The predominant histological subtype, urothelial bladder carcinoma, is characterized by high recurrence rates, progression and both primary and acquired resistance to platinum-based therapy, which impose a considerable economic burden on health-care systems and have substantial effects on the quality of life and the overall outcomes of patients with bladder cancer. The incidence of urothelial tumours is increasing owing to population growth and ageing, so novel therapeutic options are vital. Based on work by The Cancer Genome Atlas project, which has identified targetable vulnerabilities in bladder cancer, immune checkpoint inhibitors (ICIs) have arisen as an effective alternative for managing advanced disease. However, although ICIs have shown durable responses in a subset of patients with bladder cancer, the overall response rate is only ~15-25%, which increases the demand for biomarkers of response and therapeutic strategies that can overcome resistance to ICIs. In ICI non-responders, cancer cells use effective mechanisms to evade immune cell antitumour activity; the overlapping Warburg effect machinery of cancer and immune cells is a putative determinant of the immunosuppressive phenotype in bladder cancer. This energetic interplay between tumour and immune cells leads to metabolic competition in the tumour ecosystem, limiting nutrient availability and leading to microenvironmental acidosis, which hinders immune cell function. Thus, molecular hallmarks of cancer cell metabolism are potential therapeutic targets, not only to eliminate malignant cells but also to boost the efficacy of immunotherapy. In this sense, integrating the targeting of tumour metabolism into immunotherapy design seems a rational approach to improve the therapeutic efficacy of ICIs.

Long non-coding RNA MALAT1 activates autophagy and promotes cell proliferation by downregulating microRNA-204 expression in gastric cancer

Gastric cancer (GC) is one of the major diseases that threaten human health. Although the development of novel drugs has significantly improved the efficacy of GC chemotherapy, the 5-year survival rate of patients with GC remains unsatisfactory. In the present study, the role and mechanism of the long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in GC proliferation was investigated. Clinical specimens and cancer cells were analyzed by western blotting or immunofluorescence. Reverse transcription-quantitative polymerase chain reaction analysis of 57 paired GC and non-tumorous tissues revealed elevated expression of MALAT1 in GC tissues compared with controls. In addition, increased MALAT1 was associated with elevated levels of microtubule-associated protein 1 light chain 3β (LC3B) and antigen Ki67, which are autophagy and proliferation markers, respectively. MTT and colony formation assay results demonstrated that MALAT1 promoted GC cell proliferation. To the best of our knowledge, the present study was the first to demonstrate that upregulated MALAT1 was associated with increased autophagy activation in GC tissues. Furthermore, this study reported that MALAT1 increased cell proliferation and enhanced autophagy activation in GC cells. In addition, the results revealed that MALAT1 inhibited microRNA (miR)-204 expression in GC cells. The present study also demonstrated that miR-204 repressed autophagy through the downregulation of LC3B and transient receptor potential melastatin 3 expression in GC cells. These results indicated that MALAT1 activated autophagy and promoted cell proliferation by downregulating miR-204 expression in GC.

Hypoxia differentially regulates estrogen receptor alpha in 2D and 3D culture formats

Hypoxia is a common feature in solid tumors. Clinical samples show a positive correlation between the expression of the hypoxia-inducible factor HIF-1α and estrogen receptor alpha (ERα) and a negative correlation between HIF-1α and hormone sensitivity. Results from monolayer cultures are in contention with clinical observations, showing that ER (+) cell lines no longer express ERα under hypoxic conditions (1% O2). Here, we compared the impact of hypoxia on the ERα signaling pathway for T47D cells in a 2D and 3D culture format. In the 2D format, the cells were cultured as monolayers. In the 3D format, paper-based scaffolds supported cells suspended in a collagen matrix. Using ELISA, Western blot, and immunofluorescence measurements, we show that hypoxia differentially regulates ERα protein levels in a culture environment-dependent manner. In the 2D format, the protein levels are significantly decreased in hypoxia. In the 3D format, the protein levels are maintained in hypoxia. Hypoxia reduced ERα transcriptional activation in both culture formats. These results highlight the importance of considering tissue dimensionality for in vitro studies. They also show that ERα protein levels in hypoxia are not an accurate indicator of ERα transcriptional activity, and confirm that a positive stain for ERα in a clinical sample may not necessarily indicate hormone sensitivity.

Lactate Is a Natural Suppressor of RLR Signaling by Targeting MAVS

RLR-mediated type I IFN production plays a pivotal role in elevating host immunity for viral clearance and cancer immune surveillance. Here, we report that glycolysis, which is inactivated during RLR activation, serves as a barrier to impede type I IFN production upon RLR activation. RLR-triggered MAVS-RIG-I recognition hijacks hexokinase binding to MAVS, leading to the impairment of hexokinase mitochondria localization and activation. Lactate serves as a key metabolite responsible for glycolysis-mediated RLR signaling inhibition by directly binding to MAVS transmembrane (TM) domain and preventing MAVS aggregation. Notably, lactate restoration reverses increased IFN production caused by lactate deficiency. Using pharmacological and genetic approaches, we show that lactate reduction by lactate dehydrogenase A (LDHA) inactivation heightens type I IFN production to protect mice from viral infection. Our study establishes a critical role of glycolysis-derived lactate in limiting RLR signaling and identifies MAVS as a direct sensor of lactate, which functions to connect energy metabolism and innate immunity.

LINK-A promotes cell proliferation through the regulation of aerobic glycolysis in non-small-cell lung cancer

Purpose

Non-small-cell lung cancer (NSCLC) is the one of the most common malignancies worldwide, and occurs at a higher frequency in male individuals. Little is known about the role of the long intergenic noncoding RNA for kinase activation (LINK-A) in NSCLC, so in the present study we assessed its potential role on cell proliferation in NSCLC.

Methods

Expression levels of LINK-A in NSCLC tissues and cell lines were detected by quantitative reverse-transcription polymerase chain reaction. LINK-A was knocked down and overexpressed separately in A549 cells and NCI-H1299 cells. The effect of LINK-A expression on cell proliferation was determined by MTT assay. The correlation between LINK-A and hexokinase II (HKII) expression was investigated by Western blot and HKII Activity Assay. Glucose consumption and lactate production assay were used to investigate the aerobic glycolysis in NSCLC cells. The effect of LINK-A in vivo was determined by xenograft assay.

Results

LINK-A expression levels were increased in NSCLC tissues compared with normal tissues. Moreover, LINK-A expression was positively correlated with NSCLC clinicopathological characteristics and survival rate, while knockdown of LINK-A reduced NSCLC cell proliferation. LINK-A expression was also positively correlated with HKII, and NSCLC cells with low LINK-A expression were found to have significantly reduced HKII protein expression, accompanied by a reduction in enzyme activity levels. Both in vitro and in vivo experiments showed that LINK-A expression affected glucose consumption and lactate production through regulation of HKII expression.

Conclusion

These data suggest that the functions of LINK-A in NSCLC might play a key role in tumor progression and that LINK-A could be a promising predictive biomarker and potential therapeutic target for NSCLC.

Histone demethylase JMJD1A promotes colorectal cancer growth and metastasis by enhancing Wnt/β-catenin signaling

The histone demethylase Jumonji domain containing 1A (JMJD1A) is overexpressed in multiple tumors and promotes cancer progression. JMJD1A has been shown to promote colorectal cancer (CRC) progression, but its molecular role in CRC is unclear. Here, we report that JMJD1A is overexpressed in CRC specimens and that its expression is positively correlated with that of proliferating cell nuclear antigen (PCNA). JMJD1A knockdown decreased the expression of proliferative genes such as c-Myc, cyclin D1, and PCNA, suppressed CRC cell proliferation, arrested cell cycle progression, and reduced xenograft tumorigenesis. Furthermore, JMJD1A knockdown inhibited CRC cell migration, invasion, and lung metastasis by decreasing matrix metallopeptidase 9 (MMP9) expression and enzymatic activity. Moreover, bioinformatics analysis of GEO profile datasets revealed that JMJD1A expression in human CRC specimens is positively correlated with the expression of Wnt/β-catenin target genes, including c-Myc, cyclin D1, and MMP9. Mechanistically, JMJD1A enhanced Wnt/β-catenin signaling by promoting β-catenin expression and interacting with β-catenin to enhance its transactivation. JMJD1A removed the methyl groups of H3K9me2 at the promoters of c-Myc and MMP9 genes. In contrast, the JMJD1A^H1120Y variant, which lacked demethylase activity, did not demethylate H3K9me2 at these promoters, failed to assist β-catenin to induce the expression of Wnt/β-catenin target genes, and failed to promote CRC progression. These findings suggest that JMJD1A's demethylase activity is required for Wnt/β-catenin activation. Of note, high JMJD1A levels in CRC specimens predicted poor cancer outcomes. In summary, JMJD1A promotes CRC progression by enhancing Wnt/β-catenin signaling, implicating JMJD1A as a potential molecular target for CRC management.

Ras GTPase-Activating-Like Protein IQGAP1 (IQGAP1) Promotes Breast Cancer Proliferation and Invasion and Correlates with Poor Clinical Outcomes

BACKGROUND Breast cancer is one of the most common female cancers in the world. As a key integrator of cell signaling pathways, IQGAP1 contributes to the development and progression of several cancers. However, the exact effects and molecular mechanisms of IQGAP1 in breast cancer progression remain poorly understood. MATERIAL AND METHODS In the present study, IQGAP1 expression was measured in 96 paired breast cancer samples and the corresponding adjacent non-cancerous tissues by immunohistochemistry and quantitative polymerase chain reaction. To further explore the biological function of IQGAP1 in breast cancer cells, we knocked down IQGAP1 expression in MCF-7 cells and overexpressed it in SK-BR-3 cells. RESULTS IQGAP1 was specifically upregulated in breast cancer tissues compared with the corresponding adjacent non-cancerous tissues. Moreover, IQGAP1 expression was positively correlated with breast cancer survival rate. IQGAP1 also promoted breast cancer cell proliferation and cell cycle progression and suppressed apoptosis. CONCLUSIONS In conclusion, our results suggest that IQGAP1 plays an important role in the cell proliferation and invasion of human breast cancer cells, thus indicating that IQGAP1 may be a potential therapeutic target for the treatment of human breast cancer.

Knockdown of fibrous sheath interacting protein 1 expression reduces bladder urothelial carcinoma cell proliferation and induces apoptosis via inhibition of the PI3K/AKT pathway

Background

FSIP1 plays a vital role in tumorigenesis and cancer progression. In bladder cancer, FSIP1 overexpression was associated with poor prognosis of bladder urothelial carcinoma. In this study, we investigated whether FSIP1 is essential in the progression of bladder cancer and the mechanism by which it mediates this effect.

Methods

FSIP1 expression was knocked down in bladder cancer cells using lentiviral-mediated short hairpin RNA (shRNA). FSIP1 expression was detected using Western blotting, immunohistochemistry (IHC), and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). The effects of FSIP1 knockdown on tumor cells were assessed using colony formation, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and flow cytometry (FCM) apoptosis assays in vitro and BALB/c nude mouse xenograft model in vivo.

Results

The findings suggested that FSIP1 protein was highly expressed in bladder cancer cell lines. Knockdown of FSIP1 resulted in reduced tumor cell viability, cell cycle arrest at G₀/G₁ phase and apoptosis of bladder cancer cell lines (P<0.05). Moreover, knockdown of FSIP1 expression suppressed the tumor formation and growth of bladder cancer xenografts (P<0.05). At the gene level, knockdown of FSIP1 expression downregulated the activity of the PI3K/AKT signaling pathway.

Conclusion

This study demonstrated that knockdown of FSIP1 suppressed bladder cancer cell malignant behaviors in vitro and in vivo through the inhibition of the PI3K/AKT signaling pathway, suggesting that targeting FSIP1 could be further evaluated as a potential therapeutic strategy in bladder cancer.

Wnt7a activates canonical Wnt signaling, promotes bladder cancer cell invasion, and is suppressed by miR-370-3p

Once urinary bladder cancer (UBC) develops into muscle-invasive bladder cancer, its mortality rate increases dramatically. However, the molecular mechanisms of UBC invasion and metastasis remain largely unknown. Herein, using 5637 UBC cells, we generated two sublines with low (5637 NMI) and high (5637 HMI) invasive capabilities. Mass spectrum analyses revealed that the Wnt family protein Wnt7a is more highly expressed in 5637 HMI cells than in 5637 NMI cells. We also found that increased Wnt7a expression is associated with UBC metastasis and predicted worse clinical outcome in UBC patients. Wnt7a depletion in 5637 HMI and T24 cells reduced UBC cell invasion and decreased levels of active β-catenin and its downstream target genes involved in the epithelial-to-mesenchymal transition (EMT) and extracellular matrix (ECM) degradation. Consistently, treating 5637 NMI and J82 cells with recombinant Wnt7a induced cell invasion, EMT, and expression of ECM degradation-associated genes. Moreover, TOP/FOPflash luciferase assays indicated that Wnt7a activated canonical β-catenin signaling in UBC cells, and increased Wnt7a expression was associated with nuclear β-catenin in UBC samples. Wnt7a ablation suppressed matrix metalloproteinase 10 (MMP10) expression, and Wnt7a overexpression increased MMP10 promoter activity through two TCF/LEF promoter sites, confirming that Wnt7a-mediated MMP10 activation is mediated by the canonical Wnt/β-catenin pathway. Of note, the microRNA miR-370-3p directly repressed Wnt7a expression and thereby suppressed UBC cell invasion, which was partially restored by Wnt7a overexpression. Our results have identified an miR-370-3p/Wnt7a axis that controls UBC invasion through canonical Wnt/β-catenin signaling, which may offer prognostic and therapeutic opportunities.

Transcriptional Regulation of the Warburg Effect in Cancer by SIX1

Aerobic glycolysis (the Warburg effect) facilitates tumor growth, and drugs targeting aerobic glycolysis are being developed. However, how the Warburg effect is directly regulated is largely unknown. Here we show that transcription factor SIX1 directly increases the expression of many glycolytic genes, promoting the Warburg effect and tumor growth in vitro and in vivo. SIX1 regulates glycolysis through HBO1 and AIB1 histone acetyltransferases. Cancer-related SIX1 mutation increases its ability to promote aerobic glycolysis and tumor growth. SIX1 glycolytic function is directly repressed by microRNA-548a-3p, which is downregulated, inversely correlates with SIX1, and is a good predictor of prognosis in breast cancer patients. Thus, the microRNA-548a-3p/SIX1 axis strongly links aerobic glycolysis to carcinogenesis and may become a promising cancer therapeutic target.

Honokiol inhibits bladder cancer cell invasion through repressing SRC-3 expression and epithelial-mesenchymal transition

Urinary bladder cancer (UBC) is one of the most common urological cancer types. Muscle invasive bladder cancer possesses high propensity for metastasis with poor prognosis. Honokiol is a lignan isolated from Magnolia officinalis with high bioavailability and potent anticancer effects. The results of the present study demonstrated that honokiol significantly inhibited UBC cell migration and invasion in a dose-dependent manner compared with the vehicle-treated control group. In addition, honokiol treatment suppressed epithelial-mesenchymal transition by induction of E-cadherin and repression of N-cadherin. Honokiol was capable of significantly downregulating the expression of cell invasion-associated genes, steroid receptor coactivator-3 (SRC-3), matrix metalloproteinase (MMP)-2 and Twist1. Notably, the inhibition of UBC cell invasion by honokiol was reversed by reintroduction of oncoprotein SRC-3 expression, with the restoration of MMP-2 and Twist1, and reduction of E-cadherin expression. Furthermore, the results of the luciferase assay confirmed that SRC-3 could regulate Twist1 promoter activity. Taken together, the results of the present study suggest that honokiol is a promising agent against UBC cell invasion via downregulation of SRC-3 and its target genes.

TGFβ1 Promotes Gemcitabine Resistance through Regulating the LncRNA-LET/NF90/miR-145 Signaling Axis in Bladder Cancer

High tumor recurrence is frequently observed in patients with urinary bladder cancers (UBCs), with the need for biomarkers of prognosis and drug response. Chemoresistance and subsequent recurrence of cancers are driven by a subpopulation of tumor initiating cells, namely cancer stem-like cells (CSCs). However, the underlying molecular mechanism in chemotherapy-induced CSCs enrichment remains largely unclear. In this study, we found that during gemcitabine treatment lncRNA-Low Expression in Tumor (lncRNA-LET) was downregulated in chemoresistant UBC, accompanied with the enrichment of CSC population. Knockdown of lncRNA-LET increased UBC cell stemness, whereas forced expression of lncRNA-LET delayed gemcitabine-induced tumor recurrence. Furthermore, lncRNA-LET was directly repressed by gemcitabine treatment-induced overactivation of TGFβ/SMAD signaling through SMAD binding element (SBE) in the lncRNA-LET promoter. Consequently, reduced lncRNA-LET increased the NF90 protein stability, which in turn repressed biogenesis of miR-145 and subsequently resulted in accumulation of CSCs evidenced by the elevated levels of stemness markers HMGA2 and KLF4. Treatment of gemcitabine resistant xenografts with LY2157299, a clinically relevant specific inhibitor of TGFβRI, sensitized them to gemcitabine and significantly reduced tumorigenecity in vivo. Notably, overexpression of TGFβ1, combined with decreased levels of lncRNA-LET and miR-145 predicted poor prognosis in UBC patients. Collectively, we proved that the dysregulated lncRNA-LET/NF90/miR-145 axis by gemcitabine-induced TGFβ1 promotes UBC chemoresistance through enhancing cancer cell stemness. The combined changes in TGFβ1/lncRNA-LET/miR-145 provide novel molecular prognostic markers in UBC outcome. Therefore, targeting this axis could be a promising therapeutic approach in treating UBC patients.

LMP1-mediated glycolysis induces myeloid-derived suppressor cell expansion in nasopharyngeal carcinoma

Myeloid-derived suppressor cells (MDSCs) are expanded in tumor microenvironments, including that of Epstein–Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC). The link between MDSC expansion and EBV infection in NPC is unclear. Here, we show that EBV latent membrane protein 1 (LMP1) promotes MDSC expansion in the tumor microenvironment by promoting extra-mitochondrial glycolysis in malignant cells, which is a scenario for immune escape initially suggested by the frequent, concomitant detection of abundant LMP1, glucose transporter 1 (GLUT1) and CD33⁺ MDSCs in tumor sections. The full process has been reconstituted in vitro. LMP1 promotes the expression of multiple glycolytic genes, including GLUT1. This metabolic reprogramming results in increased expression of the Nod-like receptor family protein 3 (NLRP3) inflammasome, COX-2 and P-p65 and, consequently, increased production of IL-1β, IL-6 and GM-CSF. Finally, these changes in the environment of malignant cells result in enhanced NPC-derived MDSC induction. One key step is the physical interaction of LMP1 with GLUT1 to stabilize the GLUT1 protein by blocking its K48-ubiquitination and p62-dependent autolysosomal degradation. This work indicates that LMP1-mediated glycolysis regulates IL-1β, IL-6 and GM-CSF production through the NLRP3 inflammasome, COX-2 and P-p65 signaling pathways to enhance tumor-associated MDSC expansion, which leads to tumor immunosuppression in NPC.

The expression of the Epstein-Barr virus (EBV) oncogenic protein denoted latent membrane protein 1 (LMP1) varies in patients with NPC and is linked to tumorigenesis and tumor immunosuppression, but the molecular mechanism through which LMP1 leads to tumor immune escape remains unknown. Work to date suggests that the expansion of tumor-associated myeloid-derived suppressor cells (MDSCs) is the main cause of tumor immunosuppression such as that found in NPC. Here, we found that tumor LMP1 expression is correlated with glucose transporter 1 (GLUT1) levels, CD33⁺ MDSC number and unfavorable survival in patients with NPC. Based on the results of our in vitro analysis, LMP1 promotes GLUT1-dependent glycolysis in NPC cells, resulting in activation of the Nod-like receptor family protein 3 (NLRP3) inflammasome, COX-2 and P-p65 signaling pathways and subsequently increased IL-1β, IL-6 and GM-CSF production. Importantly, LMP1 interacts with GLUT1 to stabilize the GLUT1 protein by disrupting its K48-linked ubiquitination and autolysosomal degradation in a p62-dependent manner and up-regulating the GLUT1 mRNA and protein levels by inducing p65 activation. Therefore, we determined that GLUT1-dependent glycolysis is required for tumor-induced MDSC differentiation and that this process is associated with LMP1 expression. Based on our findings, LMP1-mediated glycolysis is a key process involved in controlling tumor immunosuppression and directly contributes to oncogenesis.

MgF3- and AlF4- transition state analogue complexes of yeast phosphoglycerate kinase

The phospho-transfer mechanism of yeast phosphoglycerate kinase (PGK) has been probed through formation of trifluoromagnesate (MgF₃^-) and tetrafluoroaluminate (AlF₄^-) transition state analogue complexes and analyzed using ¹⁹F, ¹H waterLOGSY and ¹H chemical shift perturbation NMR spectroscopy. We observed the first ¹⁹F NMR spectroscopic evidence for the formation of metal fluoride transition state analogues of yeast PGK and also observed significant changes to proton chemical shifts of PGK in the presence, but not in the absence, of fluoride upon titration of ligands, providing indirect evidence of the formation of a closed ternary transition state. WaterLOGSY NMR spectroscopy experiments using an uncompetitive model were used in an attempt to measure ligand binding affinities within the transition state analogue complexes.

Metabolic phenotype of bladder cancer

Metabolism of bladder cancer represents a key issue for cancer research. Several metabolic altered pathways are involved in bladder tumorigenesis, representing therefore interesting targets for therapy. Tumor cells, including urothelial cancer cells, rely on a peculiar shift to aerobic glycolysis-dependent metabolism (the Warburg-effect) as the main energy source to sustain their uncontrolled growth and proliferation. Therefore, the high glycolytic flux depends on the overexpression of glycolysis-related genes (SRC-3, glucose transporter type 1 [GLUT1], GLUT3, lactic dehydrogenase A [LDHA], LDHB, hexokinase 1 [HK1], HK2, pyruvate kinase type M [PKM], and hypoxia-inducible factor 1-alpha [HIF-1α]), resulting in an overproduction of pyruvate, alanine and lactate. Concurrently, bladder cancer metabolism displays an increased expression of genes favoring the pentose phosphate pathway (glucose-6-phosphate dehydrogenase [G6PD]) and the fatty-acid synthesis (fatty acid synthase [FASN]), along with a decrease of AMP-activated protein kinase (AMPK) and Krebs cycle activities. Moreover, the PTEN/PI3K/AKT/mTOR pathway, hyper-activated in bladder cancer, acts as central regulator of aerobic glycolysis, hence contributing to cancer metabolic switch and tumor cell proliferation. Besides glycolysis, glycogen metabolism pathway plays a robust role in bladder cancer development. In particular, the overexpression of GLUT-1, the loss of the tumor suppressor glycogen debranching enzyme amylo-α-1,6-glucosidase, 4-α-glucanotransferase (AGL), and the increased activity of the tumor promoter enzyme glycogen phosphorylase impair glycogen metabolism. An increase in glucose uptake, decrease in normal cellular glycogen storage, and overproduction of lactate are consequences of decreased oxidative phosphorylation and inability to reuse glucose into the pentose phosphate and de novo fatty acid synthesis pathways. Moreover, AGL loss determines augmented levels of the serine-to-glycine enzyme serine hydroxymethyltransferase-2 (SHMT2), resulting in an increased glycine and purine ring of nucleotides synthesis, thus supporting cells proliferation. A deep understanding of the metabolic phenotype of bladder cancer will provide novel opportunities for targeted therapeutic strategies.

JadX is a Disparate Natural Product Binding Protein

We report that JadX, a protein of previously undetermined function coded for in the jadomycin biosynthetic gene cluster of Streptomyces venezuelae ISP5230, affects both chloramphenicol and jadomycin production levels in blocked mutants. Characterization of recombinant JadX through protein-ligand interactions by chemical shift perturbation and WaterLOGSY NMR spectroscopy resulted in the observation of binding between JadX and a series of jadomycins and between JadX and chloramphenicol, another natural product produced by S. venezuelae ISP5230. These results suggest JadX to be an unusual class of natural product binding protein involved in binding structurally disparate natural products. The ability for JadX to bind two different natural products in vitro and the ability to affect production of these secondary metabolites in vivo suggest a potential role in regulation or signaling. This is the first example of functional characterization of these JadX-like proteins, and provides insight into a previously unobserved regulatory process.

Metabolic coupling in urothelial bladder cancer compartments and its correlation to tumor aggressiveness

Monocarboxylate transporters (MCTs) are vital for intracellular pH homeostasis by extruding lactate from highly glycolytic cells. These molecules are key players of the metabolic reprogramming of cancer cells, and evidence indicates a potential contribution in urothelial bladder cancer (UBC) aggressiveness and chemoresistance. However, the specific role of MCTs in the metabolic compartmentalization within bladder tumors, namely their preponderance on the tumor stroma, remains to be elucidated. Thus, we evaluated the immunoexpression of MCTs in the different compartments of UBC tissue samples (n = 111), assessing the correlations among them and with the clinical and prognostic parameters. A significant decrease in positivity for MCT1 and MCT4 occurred from normoxic toward hypoxic regions. Significant associations were found between the expression of MCT4 in hypoxic tumor cells and in the tumor stroma. MCT1 staining in normoxic tumor areas, and MCT4 staining in hypoxic regions, in the tumor stroma and in the blood vessels were significantly associated with UBC aggressiveness. MCT4 concomitant positivity in hypoxic tumor cells and in the tumor stroma, as well as positivity in each of these regions concomitant with MCT1 positivity in normoxic tumor cells, was significantly associated with an unfavourable clinicopathological profile, and predicted lower overall survival rates among patients receiving platinum-based chemotherapy. Our results point to the existence of a multi-compartment metabolic model in UBC, providing evidence of a metabolic coupling between catabolic stromal and cancer cells' compartments, and the anabolic cancer cells. It is urgent to further explore the involvement of this metabolic coupling in UBC progression and chemoresistance.

Inverse relationship of Rho kinase and myosin-light chain kinase expression in the aging human detrusor smooth muscle

Background

Rho kinase (ROCK) and myosin-light chain kinase (MLCK) are key enzymes in smooth muscle contraction. Previous data have suggested that ROCK contribution to human detrusor contraction is increasing with age. Here, we have analyzed the transcriptional expression of Rho kinase isoforms (ROCK1 and ROCK2) as well as MLCK in the aging human detrusor smooth muscle obtained from resected tissue.

Methods

Small pieces of macroscopically healthy human detrusor smooth muscle (urothelium-free) were prepared for quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR). Transcript expression (mRNA level) of the target genes ROCK1, ROCK2 and MLCK was normalized to three common reference genes (glyceraldehyde-3-phosphate dehydrogenase, β-actin, phosphoglycerate kinase 1).

Results

We found that across all ages the expression level of ROCK (i.e. ROCK1 and ROCK2 together) was almost equal to that of MLCK in the human bladder. Further, ROCK2 showed a significantly higher expression level than ROCK1. Among all subjects, there was no significant correlation of any single target gene to age, but expression levels of ROCK and MLCK were inversely correlated. Moreover, the within-subject analysis revealed that the ROCK-to-MLCK ratio showed a significantly negative correlation to age. Thus, within a given subject, there is a relative ROCK down-regulation and concomitant MLCK up-regulation.

Conclusions

Together with previous data in human detrusor specimens showing increased ROCK contribution to detrusor contraction, we speculate that the drop of the ROCK-to-MLCK ratio may occur as an attempt to compensate for the increased Rho kinase activity.

Transcriptional coregulators: emerging roles of SRC family of coactivators in disease pathology

Transcriptional coactivators have evolved as an important new class of functional proteins that participate with virtually all transcription factors and nuclear receptors (NRs) to intricately regulate gene expression in response to a wide variety of environmental cues. Recent findings have highlighted that coactivators are important for almost all biological functions, and consequently, genetic defects can lead to severe pathologies. Drug discovery efforts targeting coactivators may prove valuable for treatment of a variety of diseases.