HIF-1alpha Expression Research Articles

Chemotherapy increases CDA expression and sensitizes malignant pleural mesothelioma cells to capecitabine treatment

The combination of cisplatin and pemetrexed remains the gold standard chemotherapy for malignant pleural mesothelioma (MPM), although resistance and poor response pose a significant challenge. Cytidine deaminase (CDA) is a key enzyme in the nucleotide salvage pathway and is involved in the adaptive stress response to chemotherapy. The cytidine analog capecitabine and its metabolite 5′-deoxy-5-fluorocytidine (5’-DFCR) are converted via CDA to 5-fluorouracil, which affects DNA and RNA metabolism. This study investigated a schedule-dependent treatment strategy, proposing that initial chemotherapy induces CDA expression, sensitizing cells to subsequent capecitabine treatment. Basal CDA protein expression was low in different mesothelioma cell lines but increased in the corresponding xenografts. Standard chemotherapy increased CDA protein levels in MPM cells in vitro and in vivo in a schedule-dependent manner. This was associated with epithelial-to-mesenchymal transition and with HIF-1alpha expression at the transcriptional level. In addition, pretreatment with cisplatin and pemetrexed in combination sensitized MPM xenografts to capecitabine. Analysis of a tissue microarray (TMA) consisting of samples from 98 human MPM patients revealed that most human MPM samples had negative CDA expression. While survival curves based on CDA expression in matched samples clearly separated, significance was not reached due to the limited sample size. In non-matched samples, CDA expression before but not after neoadjuvant therapy was significantly associated with worse overall survival. In conclusion, chemotherapy increases CDA expression in xenografts, which is consistent with our in vitro results in MPM and lung cancer. A subset of matched patient samples showed increased CDA expression after therapy, suggesting that a schedule-dependent treatment strategy based on chemotherapy and capecitabine may benefit a selected MPM patient population.

STAT3 drives the expression of HIF1alpha in cancer cells through a novel super-enhancer

Aerobic glycolysis is one of the major hallmarks of malignant tumors. This metabolic reprogramming benefits the rapid proliferation of cancer cells, facilitates the formation of tumor microenvironment to support their growth and survival, and impairs the efficacy of various tumor therapies. Therefore, the elucidation of the mechanisms driving aerobic glycolysis in tumors represents a pivotal breakthrough in developing therapeutic strategies for solid tumors. HIF1α serves as a central regulator of aerobic glycolysis with elevated mRNA and protein expression across multiple tumor types. However, the mechanisms contributing to this upregulation remain elusive. This study reports the identification of a novel HIF1α super enhancer (HSE) in multiple cancer cells using bioinformatics analysis, chromosome conformation capture (3C), chromatin immunoprecipitation (ChIP), and CRISPR/Cas9 genome editing techniques. Deletion of HSE in cancer cells significantly reduces the expression of HIF1α, glycolysis, cell proliferation, colony and tumor formation ability, confirming the role of HSE as the enhancer of HIF1α in cancer cells. Particularly, we demonstrated that STAT3 promotes the expression of HIF1α by binding to HSE. The discovery of HSE will help elucidate the pathways driving tumor aerobic glycolysis, offering new therapeutic targets and potentially resolving the bottleneck in solid tumor treatment.

Tsc22d3 promotes morphine tolerance in mice through the GPX4 ferroptosis pathway.

Morphine tolerance refers to gradual reduction in response to drug with continuous or repeated use of morphine, requiring higher doses to achieve same effect. The morphine tolerance dataset GSE7762 profiles, obtained from gene expression omnibus (GEO) database, were used to identify differentially expressed genes (DEGs). Weighted Gene Co-expression Network Analysis (WGCNA) was applied to explore core modules of DEGs related to morphine tolerance. Core genes were input into Comparative Toxicogenomics Database (CTD). Animal experiments were performed to validate role of Tsc22d3 in morphine tolerance and its relationship with ferroptosis-related pathway. 500 DEGs were identified. DEGs were primarily enriched in negative regulation of brain development, neuronal apoptosis processes, and neurosystem development. Core gene was identified as Tsc22d3. Tsc22d3 gene-associated miRNAs were mmu-miR-196b-5p and mmu-miR-196a-5p. Compared to Non-morphine tolerant group, Tsc22d3 expression was significantly upregulated in Morphine tolerant group. Tsc22d3 expression was upregulated in Morphine tolerant+Tsc22d3_OE, expression of HIF-1alpha, GSH, GPX4 in GPX4 ferroptosis-related pathway showed a more pronounced decrease. As Tsc22d3 expression was downregulated in Morphine tolerant+Tsc22d3_KO, expression of HIF-1alpha, GSH, GPX4 in GPX4 ferroptosis-related pathway exhibited a more pronounced increase. Upregulation of Tsc22d3 in Morphine tolerant+Tsc22d3_OE led to a more pronounced increase in expression of apoptosis proteins (P53, Caspase-3, Bax, SMAC, FAS). The expression of inflammatory factors (IL6, TNF-alpha, CXCL1, CXCL2) showed a more pronounced increase with upregulated Tsc22d3 expression in Morphine tolerant+Tsc22d3_OE. Tsc22d3 is highly expressed in brain tissue of morphine-tolerant mice, activating ferroptosis pathway, enhancing apoptosis, promoting inflammatory responses in brain cells.

Abstract 4131: Combination therapeutic strategy to fight against triple-negative breast cancer

Abstract Triple-negative breast cancers (TNBCs) lack estrogen-and progesteron receptors and human epidermal growth factor receptor-2 (HER2) which limits the therapeutic approaches. The high metastasizing capability of TNBCs is in correlation with the poor oxygenation of the cancerous breast tissue. This leads to the activation of the hypoxia-inducible-factor 1 (HIF-1), which induces multiple target genes that are involved in tumor progression and metastasis formation. This makes HIF-1 an attractive drug target, however, HIF-1 inhibitors failed if applied in monotherapy. Therefore, our aim is to investigate the combined therapeutic effect of HIF-1 inhibitor acriflavine and paclitaxel, a commonly used taxane in TNBC treatment. The synergy assessment of the two drugs was carried out by utilizing Sulforhodamine B assay on TNBC cell lines. The in vivo toxicity and efficacy of the drug combination was tested on NOD SCID mice with orthotopically inoculated MDA-MB-231 cell line. Quantitative and qualitative analysis of multiple genes involved in tumor progression was performed by mRNA and protein expression level assessment with qPCR, western blot and immunohistochemistry methods. HIF-1 stimulation was achieved by either incubating the cells at 1% oxygen level or through CoCl2 treatment. The in vitro mRNA expression studies demonstrated that acriflavin possesses a hypoxic-effect-mitigating property on the expression of metastasis-involved- and HIF-1 target genes. Acriflavine alleviated the epithelial-mesenchymal transition of TNBC cells by increasing the expression of the epithelial marker, E-cadherin. At protein level, we detected decrease in HIF-1alpha and Phospho-Protein kinase B (Akt) and increase in p53 tumor suppressor gene expression in response to acriflavine treatment. We further established MDA-MB-231 xenograft model in mice for investigating in vivo toxicity and efficacy. The drug combination efficiently reduced the tumor size and the macrometastasis formation compared to the control groups. The protein analysis of frozen tumor tissue samples indicated that the combination therapy decreased the HIF-1alpha expression and the amount of Phospho-Akt and Phospho-Mitogen-activated protein kinases (pMAPK/pERK) in CoCl2treated mice. Additionally, expression of epithelial markers increased and that of mesenchymal markers decreased. The combination therapy led to a decrease in the platelet-derived growth factor receptor beta (PDGFRB) as well. To conclude, we identified a novel drug combination which can efficiently combat TNBC by inhibiting HIF-1 signaling, mitigating cell migration and metastasis formation and suppressing the activation of the Phosphoinositide 3-kinase (PI3K) and MAPK pathways. This work was supported by the Hungarian Thematic Excellence Program (TKP2021-EGA-44) and the National Laboratories Program - National Laboratory for Tumor Biology (NLP-17). Citation Format: Laura Svajda, Ivan Ranđelović, Sára Eszter Surguta, Marcell Baranyi, István Kenessey, Mihály Cserepes, József Tóvári. Combination therapeutic strategy to fight against triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4131.

Effect of hypoxia-inducible factor-1 alpha expression on survival in patients with metastatic cervical squamous cell carcinoma treated with first-line chemotherapy and bevacizumab.

This study addresses the gap in understanding the prognostic relevance of hypoxia-inducible factor-1 alpha (HIF-1 alpha) expression in metastatic cervical squamous cell carcinoma (SCC) patients undergoing anti-vascular endothelial growth factor (VEGF)-based therapy. A retrospective multicenter study (n = 34) explored HIF-1 alpha expression via immunohistochemistry in patients treated with platinum chemotherapy and bevacizumab. Median progression-free survival (PFS) was significantly lower in the HIF-1 alpha low score group compared to the high score group (4.9 vs 12.9 months, P = 0.014). Similarly, the median overall survival (OS) was significantly reduced in the HIF-1 alpha low score group (8.3 vs 20.4 months, P = 0.006). This study, the first of its kind, highlights the prognostic significance of HIF-1 alpha expression in metastatic cervical SCC patients treated with bevacizumab-based therapy.

10247-ET-8 HHYPOXIA-TARGETING RADIOPHARMACEUTICAL 64CU-ATSM FOR PET MONITORING WITH LOCAL THERAPY IN HIGH-GRADE GLIOMA PATIENT-DERIVED XENOGRAFT MODEL

Abstract High-grade gliomas (HGGs) are highly aggressive brain cancers characterized by the presence of hypoxia within a rapidly-growing tumor mass. Due to invasion to the surrounding brain parenchyma, these tumors commonly recur locally,, and novel local approaches are required. Here, we show a positron emission tomography (PET) integrated local therapy (PETx), to target HGGs. This technique consists of a one-step local theranostic application, followed by PET monitoring, with a hypoxia-targeting radiopharmaceutical64Cu-diacetyl-bis (N4-methylthiosemicarbazone) (64Cu-ATSM). We examined the safety and therapeutic potential of 64Cu-ATSM PETx for HGG patient-derived xenograft (PDX) tumors. PDX models were recapitulated the parent tumor phenotype of high expression of HIF-1 alpha and BNIP3, biomarkers of tissue hypoxia. We confirmed that HIF-1 alpha and BNIP3 were highly upregulated under hypoxia and 64Cu-ATSM was retained with potent cytotoxic effect under hypoxic condition in vitro. We determined that determined the maximum tolerated dose (MTD) to be 3.7 MBq in mouse. PETx using the MTD dose of 64Cu-ATSM indicated high tumor penetration, distribution, and retention of 64Cu-ATSM in PDX tumors, as compared to sham-treated mice. The 64Cu-ATSM PETx promoted DNA double-strand breaks, followed by apoptosis in tumors, and extensively prolonged overall survival with tolerable systemic toxicity. These findings indicate the potential of 64Cu-ATSM PETx to induce high uptake in the hypoxic tumor microenvironment, and strong therapeutic effects in PDX models. These findings establish 64Cu-ATSM PETx as a potential novel theranostic approach to facilitate local control of HGGs.

Abstract 17443: Wwox is a Critical Regulator of Pulmonary Artery Smooth Muscle Cell Homeostasis

Introduction: Pulmonary artery smooth muscle (PASMC) proliferation and apoptosis resistance are characteristic of pulmonary arterial hypertension (PAH). Expression loss of the tumor suppressor WW-domain containing oxidoreductase (WWOX) promotes cell survival and metabolic reprograming in cancer. We hypothesized that loss of WWOX expression in PASMC promotes pulmonary vascular remodeling by similar mechanisms. Methods and Results: mRNA and protein levels of WWOX are decreased in PASMC from patients with PAH, and in rat models of pulmonary hypertension (Sugen/ hypoxia and monocrotaline). PASMC-specific conditional Wwox knockout mice (WWOX-SMC KO) were treated with tamoxifen or vehicle for 5 days and exposed to 10% hypoxia for 4 weeks. WWOX-SMC KO animals developed worse hypoxia induced PH with increased right ventricular systolic pressure, right ventricular hypertrophy and pulmonary vascular remodeling, compared to control animals. WWOX loss via siRNA decreased mRNA and protein levels of BMPRII, upregulated HIF 1alpha expression, increased hPASMC proliferation and migration. RNAseq revealed dysregulation in multiple pathways in WWOX-silenced hPASMCs, including cell-cycle regulation, TGF-β, mTOR and STAT3 signaling. Loss of WWOX showed decreased basal and maximal respiration, ATP production, reduced glycolytic capacity (40% in relation to control) and decreased mRNA expression of glycolytic enzymes (HK2, PFK1, PKM), generating 58% less lactate, and reduced mRNA expression of lactate dehydrogenase A. These cells exhibited increased mRNA and protein expression of glutaminase-1 and citrate lyase and had higher dependency on fatty acid oxidation and glutaminolysis compared to glucose, suggesting that these pathways are used when WWOX is suppressed. We also found mitochondrial hyperpolarization (JC-1 assay), decreased Sirtuin 3 expression, increased expression of acetylated manganese-superoxide dismutase, high production of reactive oxygen species and mitochondrial fission, indicating that loss of WWOX contributes to mitochondrial dysfunction. Conclusion: Loss of WWOX promotes cell cycle progression, proliferation, and metabolic reprogramming in PASMCs. Further studies are ongoing to better understand these effects.

Oxydative stress in type 2 diabetic patients: involvement of HIF-1 alpha AND mTOR genes expression

Biochemical and genetic mechanisms of oxidative stress (OS) developing in blood of patients with type 2 Diabetes mellitus (T2DM) were studied. Twenty patients with T2DM and 10 healthy persons participated in this study. Lipid peroxidation, the content of protein carbonyls and H2O2 production were measured in blood plasma and erythrocytes as OS biomarkers. Activity of SOD, catalase, and GPx as well as reduced glutathionе (GSH) level in plasma and erythrocytes were estimated. The gene expression of key regulators of oxygen and metabolic homeostasis (HIF-1α and mTOR) in leukocytes was studied. It was found a significant rise of TBARS and protein carbonyls content in plasma as well as of H2O2 production in erythrocytes from patients with T2DM compared to control. The diabetic patients also demonstrated an increase in the SOD and catalase activity in plasma and significantly lower GSH content and GPx activity in erythrocytes compared to the healthy participants. The established marked inhibition of mTOR gene expression and the tendency to an increase in HIF-1α gene expression in leukocytes of patients with T2DM may serve as a protective mechanism which counteracts OS developing and oxidative cell damage. Keywords: HIF-1α, mTOR, oxidative stress, type 2 diabetes mellitus

Abstract 3960: Therapeutic targeting of HIF-1 alpha induced CD73 expression in experimental esophageal adenocarcinoma

Abstract Introduction: Esophageal adenocarcinoma (EAC) is one of the most aggressive human cancers with poor prognosis, and the overall 5-year survival rate is less than 20 percent. Prognosis for EAC remains poor even with modern combination therapies due to high resistance to chemotherapy. Therefore, new therapeutic approaches for EAC treatment improvements are urgently needed. Hypoxia or insufficient tissue oxygenation contributes to cancer aggressiveness and poor clinical prognosis. Overexpression of hypoxia-inducible factor 1-alpha (HIF-1 alpha) and immunosuppressive CD73, an ecto-5’-nucleotidase enzyme in cancer can give rise to tumor progression with drug resistance. CD73 has never been proposed as a therapeutic target in EAC and its relationship with hypoxia or HIF-1 alpha has not also been investigated in EAC. In this study, we therefore investigated the therapeutic targeting of HIF-1 alpha and CD73 by acriflavine in experimental EAC. Methods: Hypoxia in EAC cells were induced by 3D culture and hypoxic exposure. NanoCulture® plates and dishes were used for 3D cultures. For hypoxic exposure, cells were placed in a sealed modular incubator chamber flushed with a gas mixture containing 1% O2, 5% CO2 and 94% N2. Hypoxic status was detected by adding hypoxia probe LOX-1 and fluorescent microscopy. Nanoparticle albumin-bound paclitaxel (NPT) was used as chemotherapeutic agent, whereas acriflavine was used as hypoxia-targeting agent. In vitro cell growth was detected by WST-1 and Cell Titer-Glo (CTG) luminescent assays, in vivo tumor growth was detected by measuring subcutaneous xenografts, apoptosis was detected by cleaved caspase 3/PARP expressions and hypoxia-targeting was detected by HIF-1 alpha/CD73 expressions. Results: We observed overexpression of both HIF-1 alpha and CD73 in 3D culture and hypoxic exposure of EAC cells. Interestingly acriflavine treatment drastically inhibited both HIF-1 alpha and CD73 expression in EAC 3D culture and hypoxic exposure. 3D culture was more resistant to antiproliferative effect of chemotherapeutic agent NPT over 2D monolayer culture. Contrary to that, hypoxia-targeting agent acriflavine showed stronger antiproliferative effects in 3D culture than in 2D culture. We also observed hypoxia inside the 3D culture spheroids. In addition, acriflavine showed significant in vivo antitumor efficacy both as monotherapy and in combination with NPT. In subcutaneous xenografts using OE19 EAC cells, acriflavine monotherapy exhibited a significant decrease in relative tumor volume to 55.02% compared to control (p=0.04) and addition of NPT with acriflavine also showed a significant enhancement effect of tumor regression as tumor size decreased to 32.70% compared to control (p=0.002). Conclusion: These results support the potential of acriflavine as HIF-1 alpha and CD73 targeting and its combination with chemotherapy NPT as an effective option for EAC therapy. Citation Format: Md Sazzad Hassan, Aktar Ali, Saisantosh Ponna, Dimitri Scofield, Niranjan Awasthi, Mark Jantz, Urs von Holzen. Therapeutic targeting of HIF-1 alpha induced CD73 expression in experimental esophageal adenocarcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3960.

Prognostic histological markers in oral tongue squamous cell carcinoma patients treated with (chemo)radiotherapy.

Treatment of oral tongue squamous cell carcinoma (OTSCC) frequently includes surgery with postoperative radiotherapy (RT) or chemoradiotherapy (CRT). Resistance to RT or CRT remains a major clinical challenge and highlights the need to identify predictive markers for it. We included 71 OTSCC patients treated with surgery combined with RT or CRT. We evaluated the association between tumor budding, tumor-stroma ratio (TSR), depth of invasion (DOI), tumor-infiltrating lymphocytes (TILs), hypoxia-inducible factor-1alpha (HIF-1alpha) expression, octamer-binding transcription factor 4 (OCT4) expression, high-endothelial venules (HEVs), and disease-free survival (DFS) using uni- and multivariate analyses. No significant association was observed between the different histological and molecular markers (TSR, DOI, TILs, HEV, HIF-1alph, OCT4) and DFS. However, an associative trend between DOI, budding, and DFS was noted. Further studies with larger cohorts are needed to explore the prognostic value of DOI and budding for OTSCC patients treated with postoperative RT or CRT.

Thrombospondin-1 induction and VEGF reduction by proteasome inhibition

The present study focuses on investigating the expression of thrombospondin-1 (TSP-1), a natural inhibitor of neovascularization. Immunofluorescent staining was used to detect the expression of TSP-1 in rabbit corneal tissue with vascularization induced by limbectomy. TSP-1 was detected in healthy and Cultured Autologous Oral Mucosal Epithelial Cell Sheet (CAOMECS) grafted rabbit corneas. TSP-1 was not detected in diseased corneas. Rabbit and human primary oral mucosal and corneal epithelial cells were cultured and treated with proteasome inhibitor (PI) in vitro. Changes in the expression of TSP-1, HIF-1 alpha and 2 alpha, VEGF-A, and VEGF receptor were analyzed by Western blotting. Neovascularization developed in rabbits’ corneas as early as 1 month after limbectomy and was stable for at least 3 months. HIF-1 alpha and VEGF-A expression was reduced in CAOMECS grafted corneas, as compared to sham corneas. While TSP-1 expression was decreased in injured corneas, it was expressed in CAOMECS grafted corneas, but still less expressed compared to healthy corneas. PI treatment, of human oral mucosal and corneal epithelial cells increased TSP-1 expression and reduced VEGF-A expression. The results showed that TSP-1 expression was lost in injured corneal surface and that CAOMECS grafting restored TSP-1 expression to certain extent. Proteasome inhibition treatment increased TSP-1 and decreased VEGF-A expression in human oral mucosal and corneal epithelial cells. The result suggests that corneal neovascularization could be managed with the inhibition of the proteasome after CAOMECS grafting and increase corneal transparency.

Whole-tumor histogram analysis of diffusion-weighted imaging and dynamic contrast-enhanced MRI for soft tissue sarcoma: correlation with HIF-1alpha expression.

To investigate the correlation of histogram metrics from diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters with HIF-1alpha expression in soft tissue sarcoma (STS). We enrolled 71 patients with STS who underwent 3.0-T MRI, including conventional MRI, DWI, and DCE-MRI sequences. Location, maximum tumor diameter, envelope, T2-weighted tumor heterogeneity, peritumoral edema, peritumoral enhancement, necrosis, tail-like pattern, bone invasion, and vessel/nerve invasion and/or encasement were determined using conventional MRI images. The whole-tumor histogram metrics were calculated on the apparent diffusion coefficient (ADC), Ktrans, Kep, and Ve maps. Independent-samples t test and one-way ANOVA were used for testing the differences between normally distributed categorical data with HIF-1alpha expression. Pearson and Spearman correlations and multiple linear regression analyses were performed to determine the correlations between histogram metrics and HIF-1alpha expression. Survival curves were plotted using the Kaplan-Meier method. Regarding conventional MRI features, only highly heterogeneous on T2-weighted images (55.6 ± 19.9% vs. 45.4 ± 20.5%, p = 0.041) and more than 50% necrotic area (57.3 ± 20.4% vs. 43.9 ± 19.7%, p = 0.002) were prone to indicate STS with higher HIF-1alpha expression. Histogram metrics obtained from ADC (mean, median, 10th, and 25th percentile values), Ktrans (mean, median, 75th, and 90th percentile values), and Kep (90th percentile values) were significantly correlated with HIF-1alpha expression. Multiple linear regression analysis demonstrated that more than 50% necrosis, ADCskewness, Ktrans90th, and grade III were independently associated with HIF-1alpha expression. DWI and DCE-MRI histogram parameters were significantly correlated with HIF-1alpha expression in STS. • DWI and DCE-MRI histogram parameters are correlated with HIF-1alpha expression in STS. • More than 50% necrosis, ADCskewness, Ktrans90th, and grade III were independently associated with HIF-1alpha expression in STS.

Abstract 1115: PT-112 induces potent mitochondrial stress and immunogenic cell death in human prostate cancer cell lines

Abstract Purpose: To investigate PT-112 in a human prostate cancer (PC) cell panel and assess differential sensitivity, cell death mechanism, induction of mitochondrial stress, and release of damage-associated molecular patterns (DAMPs). Background: PT-112 is a novel pyrophosphate-platinum conjugate with clinical activity in advanced solid tumors including lung, thymoma and castration-resistant PC, and in multiple myeloma. PT-112’s cancer cell death was shown previously to be independent of DNA damage. In vitro and in vivo mouse experiments have shown that PT-112 causes mitochondrial reactive oxygen species (mtROS) accumulation, DAMP release, immunogenic cell death (ICD), and T cell infiltration. Methods: Sensitivity to PT-112 was assessed in human PC cell lines (LNCap, LNCap-C4, LNCap-C4-2, DU-145, 22Rv1, VCap and PC-3) and the non-tumorigenic prostate cell line RWPE-1. We analyzed parameters involved in the cell death process such as apoptotic and necroptotic markers, mitochondrial membrane potential, and mtROS and autophagy by flow cytometry. We also evaluated PT-112’s induction of ICD markers calreticulin (CRT) cell surface exposure and ATP secretion. Finally, a possible link between HIF-1alpha expression and PT-112 sensitivity was investigated. Results: PT-112 caused growth inhibition and cancer cell death without affecting healthy RWPE-1 cells. The pan-caspase inhibitor Z-VAD-fmk significantly reduced cell death, with more mild effects seen with the RIPK1/2 inhibitor necrostatin-1 in certain cell lines. PT-112-induced cell death was accompanied by a prominent increase of mtROS and decrease in mitochondrial membrane potential, as well as by DAMP emission (ATP release and CRT exposure). PT-112 activated markers of autophagy, and there was a positive relationship between HIF-1alpha expression and the sensitivity to PT-112 in this panel. Conclusions: PT-112 was broadly active in the PC cell lines tested, while sparing benign prostate cells, indicative of PT-112 cancer cell selectivity and of activity that crosses the varied malignant prostate phenotypes, including androgen receptor positive and negative cell lines. Cell death was primarily apoptotic, as shown by the inhibitory effects of Z-VAD-fmk. Consistent with prior work reported in glycolytic murine cells, in this PC cell panel PT-112 induced mtROS accumulation and mitochondrial membrane depolarization, as well as DAMP release, demonstrating that these may be fundamental and linked responses of cancer cells to PT-112. The apparent induction of autophagy by PT-112 may be a cellular defense mechanism to drug-induced stress. The association between PT-112 sensitivity and HIF-alpha expression should be studied further, as validation of this finding could have clinical applications. Future studies will explore relationships across mitochondrial stress, ICD and HIF-1alpha in PT-112-treated cancer cells Citation Format: Ruth Soler-Agesta, Tyler D. Ames, Matthew Price, José Jimeno, Christina Y. Yim, Raquel Moreno-Loshuertos, Alberto Anel. PT-112 induces potent mitochondrial stress and immunogenic cell death in human prostate cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1115.

EFFECTS OF APOCYNIN TREATMENT AND HBO PRECONDITIONING ON IMMUNOHISTOCHEMICAL 4-HNE, HIF1 ALPHA, HIF2 ALPHA AND NGAL TISSUE EXPRESSION IN POSTISCEMIC ACUTE KIDNEY INJURY IN SHR RATS

Objective: Oxidative stress has been considered as a central aggravating factor in the development of postischemic acute kidney injury (AKI). 4-hydroxynonenal (4-HNE) is a product of lipid peroxidation and may serve as non-invasive biomarker of oxidative stress while neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker of AKI. Hypoxia-inducible factors (HIFs) are the “master’’ transcription factors responsible for gene expression in hypoxia, which play an important role in kidney injury and repair by regulating HIF target genes, including microRNAs. Design and method: The study was conducted on male SHR rats, randomly divided into following groups: sham-operated group (SHAM) AKI control group, AKI group with apocynin treatment (AKI+APO), group with HBO preconditioning before AKI induction (AKI+HBO) and group with HBO preconditioning before and apocynin treatment after AKI induction (AKI+APO+HBO). HBO preconditioning was performed by exposing to pure oxygen (2.026 bar) twice a day for two consecutive days for 60 minutes, and 24 h before AKI induction. Apocynin, NADPH oxidase inhibitor was injected 5 minutes before reperfusion. Results: AKI induction significantly decreased creatinine (CCr), urea (CU) and phosphate (CPhos) clearances when compared to SHAM group. Remarkable increase in CCr, CU, CPhos levels were observed in all treated groups (AKI+APO, AKI+HBO, AKI+APO+HBO) in comparison to AKI group. Sham – operated rats did not express 4-HNE and NGAL in any parenchymal structure. AKI induced abundant and strong glomerular expression of 4-HNE along with expression in interstitial compartment. All treatments (AKI+APO, AKI+HBO, AKI+APO+HBO) significantly decreased 4-HNE expression both in glomeruli and interstitium. Also, AKI stimulated widespread NGAL expression in renal epithelial tubular cells with fine granular appearance on the apical surface of the cells, affecting entire circumference of tubular cross-sectioning, which was decreased in all treated groups. In SHAM group, the expression of HIF1 alpha and HIF2 alpha was focal with weak intensity in glomeruli and interstitium. In AKI group, the expression was diffuse and strong, with remarkable improvement in all treated groups. Conclusions: Considering our results, we can conclude that apocynin treatment, as well as HBO preconditioning may have protective effects in postischemic acute kidney injury induced in spontaneously hypertensive rats.

The heterogeneous subclones might be induced by cycling hypoxia which was aggravated along with the luminal A tumor growth

BackgroundIn process of infiltrating growth in solid tumor, the tumor cells undergo a periodic hypoxia/reoxygenation (circulating hypoxia) microenvironment, which might be one of principle reasons to promote formation of tumor heterogeneity and treatment failure. Therefore, it is very important to study how the microenvironment of circulating hypoxia induces the heterogeneous subclones in tumors. Material and MethodsThe maximum cross-section of luminal A tumor (LAT) was selected for the expression of hypoxia inducible factor-1 alpha (HIF-1 alpha) and estrogen receptor-alpha (ER-alpha), and the correlation between it and tumor diameter was observed. The distribution of intratumoral micro-vessels were analyzed by 3D reconstruction and CD34 staining. A circulating hypoxia model of MCF-7 was established to detect the HIF-1alpha and ER-alpha. ResultsThere was a negative correlation between the expressions of ER-alpha and HIF-1alpha (c=−2.40; p = 0.044) in the LAT. As shown by 3D ultrasound image, there were less functional micro-vessels in the center than the periphery of tumor(P < 0.05). ER-alpha expression gradually decreased with the time course of cycling hypoxia, which is inversely related to the expression of HIF-1alpha. ConclusionLAT is composed of heterogeneous subclone cells which can be distinguished by ER-alpha and HIF-1alpha, which was closely related with cycling hypoxia microenvironment.

Differential Expression of Microglial BDNF in Response to Acute Hyperglycemia and Hypoxia

Diabetes is one of the most common chronic disorders that affects the homeostasis of several systems including the central nervous system (CNS). Hyperglycemia, main feature of diabetes, is involved in pathogenesis of diabetic neuropathy. In addition, hyperglycemia increases mitochondrial oxygen consumption which leads to hypoxia and affects the neuronal survival, adversely. Brain‐derived neurotrophic (BDNF) is well known as neuroprotective factor which supports the survival of the neurons in the CNS. We hypothesize that microglial BDNF has a protective role against acute hyperglycemia and hypoxia. The objective of this study is to investigate the expression of BDNF in response to hyperglycemia and hypoxia. Murine microglial cell line BV‐2 cultured in Dulbecco's Modified Eagle Medium were used to investigate the effects of increased concentrations (30, 60, 90, 120 mM) at different durations (4, 8, 24 hours) on the viability of microglial cells. In addition, the effects of hypoxia on the survival rate of these cells was also assessed. Gene and protein expression of microglial BDNF was examined in response to increased concentrations of glucose and hypoxia as well as hypoxia inducible factor (HIF1‐alpha). Increased concentrations of glucose produced significant increase in gene expression of microglial BDNF and this response was concentration‐dependent (p &lt; 0.001). On the other hand, gene expression of microglial BDNF was significantly decreased in response to hypoxia (4, 8, 24 hours) and this response was associated with reduced expression of HIF‐1 alpha (p &lt; 0.05). In conclusion, the outcomes of this study demonstrated that expression of microglial BDNF was sensitive to increased concentration of glucose and decreased levels of oxygen. Further investigation will dissect the signaling pathways that are involved in this differential expression to gain a better understanding of the protective role of microglial BDNF against glucose and oxygen variability.

Immunohistochemical expression of HIF-1α, IDH1 and TP53: Prognostic profile of Moroccan patients with diffuse glioma

Diffuse gliomas are growing brain tumors that occur in adult life. This study was designed to determine whether the immunohistochemical analysis of IDH1, HIF-1alpha, or TP53 can provide useful biomarkers of clinical severity and progression of diffuse gliomas. Also, it is hypothesized that the expression of IDH1 mutant induces HIF-1alpha. Immunohistochemical staining for HIF-1alpha, IDH1, and TP 53 was performed in biopsy or resection (sub-total or gross-total) tissue from diffuse gliomas in a clinical series of 32 patients. Associations of the HIF-1alpha, IDH1, and TP53 with clinical characteristics were evaluated and the co-expression of two biomarkers (HIF-1alpha and IDH1) was tested. Our data revealed that each biomarker is expressed in a subset of gliomas (IDH1 was positive in 56% cases, HIF-1alpha was positive in 50% cases and TP53 was positive in 44% cases). While no associations were found between clinical characteristics and the expression of HIF-1alpha, and TP53, IDH1 expression was associated with less severe clinical presentation (Karnofsky Performance Status) and disease progression and was more often expressed in females than males. In addition, there was no clear association between IDH1 and HIF-1alpha expression (21.9% of patients co-expressed IDH1 and HIF-1alpha). The current series provides clinical and immunohistochemical findings that can be useful for the clinical management of patients with diffused gliomas.

Quercetin increases mitochondrial proteins (VDAC and SDH) and downmodulates AXL and PIM-1 tyrosine kinase receptors in NRAS melanoma cells

Melanoma is a type of skin cancer with low survival rates after it has metastasized. In order to find molecular differences that could represent targets of quercetin in anti-melanoma activity, we have chosen SKMEL-103 and SKMEL-28 melanoma cells and human melanocytes as models. Firstly, we observed that quercetin was able in reducing SKMEL-103cell viability, but not in SKMEL-28. Besides that, quercetin treatment caused inhibition of AXL in both cell lines, but upregulation of PIM-1 in SKMEL-28 and downregulation in SKMEL-103. Moreover, HIF-1 alpha expression decreased in both cell lines. Interestingly, quercetin was more effective against SKMEL-103 than kinases inhibitors, such as Imatinib, Temsirolimus, U0126, and Erlotinib. Interestingly, we observed that while the levels of succinate dehydrogenase and voltage-dependent anion channel increased in SKMEL-103, both proteins were downregulated in SKMEL-28 after quercetin's treatment. Furthermore, AKT, AXL, PIM-1, ABL kinases were much more active and chaperones HSP90, HSP70 and GAPDH were highly expressed in SKMEL-103cells in comparison with melanocytes. Our findings indicate, for the first time, that the efficacy of quercetin to kill melanoma cells depends on its ability in inhibiting tyrosine kinase and upregulating mitochondrial proteins, at least when SKMEL-103 and SKMEL-28cells response were compared.

Correlation of immunohistochemical expression of HIF-1alpha and IDH1 with clinicopathological and therapeutic data of moroccan glioblastoma and survival analysis

IntroductionGlioblastomas are aggressive primary intracranial tumours of the central nervous system causing significant mortality and morbidity worldwide. ObjectiveThis study aims to evaluate the prognostic value of tissue expression by immunostaining of hypoxia-inducible factor (HIF-1α), isocitrate dehydrogenase 1 (IDH1), and tumour protein p53 in glioblastoma in Moroccan patients. The association of HIF-1α, IDH1, and p53 expression with the clinicopathological data and overall patient survival (OS) was also evaluated. Materials and methodsConfirmed glioblastomas were included in this study. Twenty-two tissue samples were obtained by neurosurgical intervention resulting from total resection, and subtotal resection or biopsy. Karnofsky index, histological type of tumour, and the status of IDH1, p53 protein, and HIF-1α expression by immunostaining were reported. ResultsThe majority of the patients were males (64%) with a sex ratio of 1.75. The average age was 54 ± 13. Median follow-up was 10.10 months and median overall survival was 10 months. The expression of HIF-1α was high in 10 samples (45%) and low in 12 (55%). There was a statistically significant difference in OS of 85% at 12 months for the subgroup of patients “HIF-1α negative IDH1 positive” p = 0.038, the unadjusted analysis showed that the group “HIF-1α positive, IDH1 positive” was a poor prognostic factor, the HR was 0.08 (95% CI: 0.009–0.756, p = 0.027). ConclusionPatients with negative HIF-1α expression and positive IDH1 expression have a better prognosis, suggesting that these two biomarkers may be useful in the search for new approaches for targeted therapy in glioblastoma.

1171-P: HORMAD1, a Novel Hypoxia-Inducible Factor-1 Target, Is Upregulated in Maternal Overnutrition-Induced Nonalcoholic Steatohepatitis (NASH)/Hepatocellular Carcinoma

We investigated whether overnutrition during pregnancy were associated with the changes in gene expressions, oxygen metabolism, and vascular and hepatic parenchymal remodeling in fetal livers at mid gestational days E14.5 of dams fed a control diet (CD group) or a high-fat diet (HFD group) during pregnancy. Synchrotron-based phase-contrast micro-CT demonstrated embryos of HFD group showed hepatomegaly accompanied with the same size umbilical vein and less portal branching, which might result in liver hypoxia. Correspondingly, fetal livers of HFD group increased the expression of HIF-1alpha. To identify genes and pathways targeted by maternal overnutrition in fetal livers, we assayed mRNA levels with microarray. We identified 430 differentially expressed genes (DEGs) including 146 upregulated- and 284 downregulated genes in fetal livers of HFD group compared with those of CD group. The up-regulated DEGs were significantly enriched in DNA alkylation, bile secretion, and the down-regulated DEGs mainly enriched in neuronal system, cell maturation. Among upregulated DEGs, a cancer/testis antigen HORMAD1 was induced by hypoxia up to 30-fold compared with that in normoxia in primary mouse hepatocytes (PMH), and the genetic inhibition of HIF-1alpha by siRNAs abolished the stimulatory effect of hypoxia on Hormad1 expression. In addition, we found three putative hypoxia response elements within the mouse Hormad1gene. Interestingly, the tumor suppressor WW domain-containing oxidoreductase (WWOX), which inhibits the activity of HIF-1alpha, were remarkably decreased in hypoxia in PMH. Finally, HORMAD1 protein was upregulated in fetal livers and NASH-based HCC in offspring of HFD group at 15 weeks old. Our results suggest that WWOX-HIF-1alpha-HORMAD1 pathway might be involved in the development of NAFLD in offspring of obese and/or diabetic pregnant woman, and be an important therapeutic target of NASH/HCC. Disclosure T. Takiyama: None. Y. Takiyama: Other Relationship; Self; Gilead Sciences, Inc., Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Mochida Pharmaceutical Co., Ltd., Roche Diabetes Care, Taisho Pharmaceutical Co., Ltd. R. Bessho: None. H. Kitsunai: None. Y. Takeda: None. H. Sakagami: None. T. Sera: None. M. Nakamura: None. S. Horike: None. Y. Nishikawa: None.