Chromodomain-helicase-DNA-binding protein 1 (CHD1) deletion is among the most common mutations in prostate cancer (PCa), but its role remains unclear. In this study, RNA sequencing was conducted in PCa cells after clustered regularly interspaced palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9)-based CHD1 knockout. Gene set enrichment analysis (GSEA) indicated upregulation of hypoxia-related pathways. A subsequent study confirmed that CHD1 deletion significantly upregulated hypoxia-inducible factor 1α (HIF1α) expression. Mechanistic investigation revealed that CHD1 deletion upregulated HIF1α by transcriptionally downregulating prolyl hydroxylase domain protein 2 (PHD2), a prolyl hydroxylase catalyzing the hydroxylation of HIF1α and thus promoting its degradation by the E3 ligase von Hippel-Lindau tumor suppressor (VHL). Functional analysis showed that CHD1 deletion promoted angiogenesis and glycolysis, possibly through HIF1α target genes. Taken together, these findings indicate that CHD1 deletion enhances HIF1α expression through PHD2 downregulation and therefore promotes angiogenesis and metabolic reprogramming in PCa.
Male ; Humans ; Von Hippel-Lindau Tumor Suppressor Protein/metabolism* ; DNA-Binding Proteins/metabolism* ; Prolyl Hydroxylases/metabolism* ; Hypoxia ; Prostatic Neoplasms/pathology* ; Glycolysis ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Cell Line, Tumor ; DNA Helicases/metabolism*

The incidence of renal cell carcinoma (RCC) is increasing. Radical cure by surgery can only be achieved in patients with early stage tumors. How to precisely use antineoplastic agents after surgery is an important problem to be solved. Most metastatic RCCs are pathologically identified as clear cell RCC (ccRCC), thus to develop agents targeting ccRCC is critical. Most clinically available targeted therapies are based on targeting some spots in specific pathways; or based on targeting new anti-tumor mechanisms, such as programmed death-1(PD-1), antibody-drug conjugates (ADC) and stem cells. There is still no targeted therapy having definite effect to most RCC patients. Only von Hippel-Lindau (VHL) pathway so far has been confirmed to be related to ccRCC development and progression; the inactivation of VHL gene causes many significant downstream gene changes. The key proteins involved in VHL pathway may be potential therapeutic targets for ccRCC. In this article, we review the current progress of targeted therapy for RCC, focus on the molecular characteristics of ccRCC, its relation to VHL pathway, the potential therapeutic targets and future clinical application for metastatic ccRCC.
Antineoplastic Agents ; therapeutic use ; Carcinoma, Renal Cell ; drug therapy ; Humans ; Kidney Neoplasms ; drug therapy ; Molecular Targeted Therapy ; Neoplasm Metastasis ; Von Hippel-Lindau Tumor Suppressor Protein ; metabolism

Hypoxia-inducible factor-1alpha (HIF-1alpha) is a key transcriptional mediator that coordinates the expression of various genes involved in tumorigenesis in response to changes in oxygen tension. The stability of HIF-1alpha protein is determined by oxygen-dependent prolyl hydroxylation, which is required for binding of the von Hippel-Lindau protein (VHL), the recognition component of an E3 ubiquitin ligase that targets HIF-1alpha for ubiquitination and degradation. Here, we demonstrate that PLD2 protein itself interacts with HIF-1alpha, prolyl hydroxylase (PHD) and VHL to promote degradation of HIF-1alpha via the proteasomal pathway independent of lipase activity. PLD2 increases PHD2-mediated hydroxylation of HIF-1alpha by increasing the interaction of HIF-1alpha with PHD2. Moreover, PLD2 promotes VHL-dependent HIF-1alpha degradation by accelerating the association between VHL and HIF-1alpha. The interaction of the pleckstrin homology domain of PLD2 with HIF-1alpha also promoted degradation of HIF-1alpha and decreased expression of its target genes. These results indicate that PLD2 negatively regulates the stability of HIF-1alpha through the dynamic assembly of HIF-1alpha, PHD2 and VHL.
Cell Line ; HEK293 Cells ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit/*metabolism ; Phospholipase D/*metabolism ; Prolyl Hydroxylases/metabolism ; Proteasome Endopeptidase Complex/*metabolism ; *Protein Interaction Maps ; Proteolysis ; Ubiquitin-Protein Ligases/metabolism ; Von Hippel-Lindau Tumor Suppressor Protein/metabolism

Antigens, Neoplasm ; metabolism ; Carbonic Anhydrase IX ; Carbonic Anhydrases ; metabolism ; Carcinoma, Renal Cell ; diagnosis ; metabolism ; pathology ; Humans ; Kidney Neoplasms ; diagnosis ; metabolism ; pathology ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Neoplasm Grading ; Prognosis ; RNA-Binding Proteins ; metabolism ; Tumor Burden ; Vascular Endothelial Growth Factor A ; metabolism ; Von Hippel-Lindau Tumor Suppressor Protein ; metabolism

OBJECTIVETo investigate clinicopathological features, molecular genetic characteristics, differential diagnoses and prognosis of renal cell carcinoma in teenagers.

METHODSMicroscopic and immunohistochemical features of 46 cases of renal cell carcinomas in teenagers were reviewed along with the clinical follow-up data. Loss of heterozygosity (LOH), analysis of von Hippel-Lindau (VHL) gene and screening for VHL gene mutations were performed in all of the tumors.

RESULTSThere were 19 Xp11.2 translocations/TFE3 gene fusions renal clear cell carcinomas (Xp11 RCCs), 9 chromophobe renal cell carcinomas (CCRCCs), 17 papillary renal cell carcinomas (PRCCs), and 1 unclassified renal cell carcinoma (RCC). All of the 19 Xp11.2 translocation RCCs showed a moderate to strong immunoreactivity for TFE, however, no TFEB expression was obtained. There were 4 histological patterns in the Xp11 RCC cases including: 8 tumors possessing a nested to papillary architecture resembling to the t(X;17) ASPL-TFE3 phenotype; 6 tumors possessing a morphologic feature like the t(X;1) PRCC-TFE3 phenotype; 4 cases morphologically resembling to clear cell RCC; and 1 Xp11 RCC case, with a special morphologic feature not searched yet in the literature, including a ground glass appearance of the nuclei accompanying occasionally with grooves on the nuclear surface; nucleoli inconspicuous with accumulation of abundant mucin-like substance in the stroma. VHL gene analysis revealed deletions at 3p25-26 in one clear cell RCC and one papillary type 2 RCC. The papillary type 2 RCC had also a family history of VHL disease, with a germline G→C mutation at a splicing site of position 553+5. There were no VHL mutations detected in the remaining 45 RCCs. Statistical analysis of tumor stage and outcome revealed that TFE+ RCCs of teen-agers were more frequently associated with a higher pT3/pT4 stage and a poorer outcome than that of the TFE-RCCs (P < 0.05).

CONCLUSIONSRCCs of the teenagers have a different morphologic spectrum and genetic background from the RCCs seen in adults. Among RCCs of the teen-agers, Xp11.2 translocation tumors are the most common RCCs and have a poorer prognosis than that of the TFE-RCCs.

Adolescent ; Adult ; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors ; genetics ; metabolism ; Carcinoma, Papillary ; genetics ; metabolism ; pathology ; Carcinoma, Renal Cell ; genetics ; metabolism ; pathology ; Child ; Child, Preschool ; Chromosomes, Human, Pair 11 ; Chromosomes, Human, X ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Gene Fusion ; Humans ; Kidney Neoplasms ; genetics ; metabolism ; pathology ; Loss of Heterozygosity ; Male ; Neoplasm Staging ; Neprilysin ; metabolism ; Phenotype ; Survival Rate ; Translocation, Genetic ; Von Hippel-Lindau Tumor Suppressor Protein ; genetics ; Young Adult ; von Hippel-Lindau Disease ; genetics

Adenoma ; metabolism ; pathology ; Adult ; Carcinoma, Renal Cell ; metabolism ; pathology ; Diagnosis, Differential ; Ear Neoplasms ; complications ; genetics ; metabolism ; pathology ; surgery ; Endolymphatic Sac ; Female ; Follow-Up Studies ; Humans ; Kidney Neoplasms ; metabolism ; pathology ; Middle Aged ; Paraganglioma ; metabolism ; pathology ; Point Mutation ; Von Hippel-Lindau Tumor Suppressor Protein ; genetics ; von Hippel-Lindau Disease ; complications ; genetics ; metabolism

OBJECTIVE: To investigate the expression of von Hippel-Lindau (VHL) protein and hypoxia inducible factor-1alpha (HIF-1alpha) in the lung cancer tissue and to detect their clinical significance. METHODS: EnVisionTM immunohistochemistry was used for detecting the expression of VHL and HIF-1alpha in routinely paraffin-embedded sections from the specimens of lung cancer (n=80) and normal lung tissues (n=20). We also analyzed the relation between the expression of VHL and HIF-1alpha and the clinical stage,differentiation,and with or without lymphatic metastasis. RESULTS: The positive rate of VHL was significantly lower in lung cancer (56.3%) than that in normal lung tissues (90.0%)(P<0.01).The positive rate of HIF-1alpha was significantly higher in lung cancer (65.0%) than that in normal lung tissues (20.0%)(P<0.01). The positive rate of VHL was significantly higher in the middle and high-differentiated, StageI~II, and no-metastasis of lymph node lung cancer tissues than that in the poorly-differentiated, Stage III~IV, metastasis of lymph node lung cancer tissues (P<0.01~0.05) .But the expression of HIF-1alpha in the lung cancer tissues was just the opposite as compared with that of VHL (P<0.05) .VHL and HIF-1alpha expression levels showed highly negative correlation (P<0.01). CONCLUSION The expression of VHL and HIF-1alpha may be important biological markers for carcinogenesis, progression, clinical biological behaviors, and prognosis of lung cancer.
Adenocarcinoma ; metabolism ; pathology ; Adult ; Aged ; Biomarkers, Tumor ; metabolism ; Carcinoma, Squamous Cell ; metabolism ; pathology ; Female ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Immunohistochemistry ; Lung Neoplasms ; metabolism ; pathology ; Male ; Middle Aged ; Von Hippel-Lindau Tumor Suppressor Protein ; metabolism

In present study, we investigated the mechanism of regulating HIF-1alpha expression by hydroxysafflor yellow A (HSYA) in Eahy 926 cell line under 1% O2 hypoxia. Eahy 926 cells were incubated with HSYA (100, 10 and 1 micromol x L(-1)) under hypoxia for the indicated time after treatment. Cell proliferation rate was detected using MTT assays. VHL and p53 location and protein expression were analyzed by immunocytochemical stain. HIF-1alpha, VHL and p53 mRNA expression were detected by RT-PCR. Protein expression of HIF-1alpha, VHL and p53 were assayed by Western blotting method. HSYA at 100 micromol x L(-1) increased Eahy 926 cells proliferation rate under hypoxia. HIF-1alpha mRNA and protein expression were up-regulated in the presence of HSYA. VHL, p53 mRNA and protein expression decreased significantly after 8 hours of treatment under hypoxia. HSYA protected Eahy 926 cells from hypoxia, and up-regulated HIF-1alpha expression partially via its inhibition of VHL and p53 expression.
Carthamus tinctorius ; chemistry ; Cell Hypoxia ; Cell Line ; Cell Proliferation ; drug effects ; Chalcone ; analogs & derivatives ; isolation & purification ; pharmacology ; Endothelial Cells ; cytology ; metabolism ; Flowers ; chemistry ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; biosynthesis ; genetics ; Plants, Medicinal ; chemistry ; Quinones ; isolation & purification ; pharmacology ; RNA, Messenger ; metabolism ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics ; Umbilical Veins ; cytology ; Up-Regulation ; Von Hippel-Lindau Tumor Suppressor Protein ; biosynthesis ; genetics

In this study, we investigated the role of Nur77, an orphan nuclear receptor, in HIF-alpha transcriptional activity. We found that Nur77 associates and stabilizes HIF-1alpha via indirect interaction. Nur77 was found to interact with pVHL in vivo via the alpha-domain of pVHL. By binding to pVHL, Nur77 competed with elongin C for pVHL binding. Moreover, Nur77-binding to pVHL inhibited the pVHL-mediated ubiquitination of HIF-1alpha and ultimately increased the stability and transcriptional activity of HIF-1alpha. The ligand-binding domain of Nur77 was found to interact with pVHL and the expression of this ligand-binding domain was sufficient to stabilize and transactivate HIF-1alpha. Under the conditions that cobalt chloride was treated or pVHL was knocked down, Nur77 could not stabilize HIF-alpha. Moreover, Nur77 could not further stabilize HIF-2alpha in A498/VHL stable cells, which is consistent with our finding that Nur77 indirectly stabilizes HIF-alpha by binding to pVHL. Thus, our results suggest that an orphan nuclear receptor Nur77 binds to pVHL, thereby stabilizes and increases HIF-alpha transcriptional activity under the non- hypoxic conditions.
Animals ; DNA-Binding Proteins/chemistry/*metabolism ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit/*genetics ; Models, Biological ; PC12 Cells ; Protein Binding ; *Protein Processing, Post-Translational ; Protein Structure, Tertiary ; Rats ; Receptors, Cytoplasmic and Nuclear/chemistry/*metabolism ; Receptors, Steroid/chemistry/*metabolism ; Thermodynamics ; Transcription Factors/chemistry/*metabolism ; Transcriptional Activation/genetics ; Ubiquitination ; Up-Regulation/*genetics ; Von Hippel-Lindau Tumor Suppressor Protein/*antagonists & inhibitors/chemistry/*metabolism

Hypoxia-inducible factor 1alpha (HIF-1alpha) is rapidly degraded by the ubiquitin-proteasome pathway under normoxic conditions. Ubiquitination of HIF-1alpha is mediated by interaction with von Hippel-Lindau tumor suppressor protein (pVHL). In our previous report, we found that hypoxia-induced active signal transducer and activator of transcription3 (STAT3) accelerated the accumulation of HIF-1alpha protein and prolonged its half-life in solid tumor cells. However, its specific mechanisms are not fully understood. Thus, we examined the role of STAT3 in the mechanism of pVHL-mediated HIF-1alpha stability. We found that STAT3 interacts with C-terminal domain of HIF-1alpha and stabilizes HIF-1alpha by inhibition of pVHL binding to HIF-1alpha. The binding between HIF-1alpha and pVHL, negative regulator of HIF-1alpha stability, was interfered dose-dependently by overexpressed constitutive active STAT3. Moreover, we found that the enhanced HIF-1alpha protein levels by active STAT3 are due to decrease of poly-ubiquitination of HIF-1alpha protein via inhibition of interaction between pVHL and HIF-1alpha. Taken together, our results suggest that STAT3 decreases the pVHL-mediated ubiquitination of HIF-1alpha through competition with pVHL for binding to HIF-1alpha, and then stabilizes HIF-1alpha protein levels.
Animals ; COS Cells ; Cell Line, Tumor ; Cercopithecus aethiops ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit/genetics/*metabolism ; Immunoblotting ; Immunoprecipitation ; Protein Binding ; STAT3 Transcription Factor/genetics/*metabolism ; Signal Transduction/genetics/physiology ; Transfection ; Ubiquitination ; Von Hippel-Lindau Tumor Suppressor Protein/genetics/*metabolism