AIM: To examine the influence of hypoxia on the in vitro growth of leukaemia cells and the activity of signalling proteins to better understand the pathophysiology of leukaemia cells in human bone marrow.
MATERIALS AND METHODS: Six human leukaemia cell lines were cultured under normoxic or hypoxic conditions. Cell growth, recovery of clonogenic cells, and the expression and activation of various signalling proteins were examined.
RESULTS: Hypoxia suppressed cell growth and the recovery of clonogenic cells. Moreover, hypoxia up-regulated hypoxia-inducible factor (HIF) 1α and HIF2α expression while suppressing the expression and activation of NOTCH1, mechanistic target of rapamycin kinase (mTOR) activation, and nuclear factor-kappa B (NF-κB) phosphorylation.
CONCLUSION: We found that hypoxia up-regulated HIF expression while it suppressed the self-renewal capacity of leukaemia cells, NOTCH activity, and expression of its down-stream signalling molecules, which differs from previous reports mentioning that HIF activates NOTCH signalling. Our findings serve to further elucidate the in vivo pathophysiology of leukaemia cells.

Gastric cancer represents a common malignancy of digestive tract with high incidence and mortality. Increasing evidence suggests that the growth of gastric tumor cells relies largely on aerobic glycolysis. Currently, many potential anti-cancer candidates are derived from natural products. Here, we evaluated the effects of oleanolic acid (OA), a triterpenoid component widely found in the plants of Oleaceae family, on aerobic glycolysis and proliferation in human MKN-45 and SGC-7901 gastric cancer cells. Our results demonstrated that OA reduced the viability and proliferation of gastric cancer cells and inhibited the expression of cyclin A and cyclin-dependent kinase 2. OA blocked glycolysis in these cells evidenced by decreases in the uptake and consumption of glucose, intracellular lactate levels and extracellular acidification rate. Glycolysis inhibitor 2-deoxy-d-glucose, similar to OA, suppressed gastric cancer cell proliferation. OA also decreased the expression and intracellular activities of glycolysis rate-limiting enzymes hexokinase 2 (HK2) and phosphofructokinase 1 (PFK1). Moreover, OA downregulated the expression of hypoxia inducible factor-1α (HIF-1α) and decreased its nuclear abundance. Upregulation of HIF-1α by deferoxamine rescued OA-inhibited HK2 and PFK1. Furthermore, OA reduced the nuclear abundance of yes-associated protein (YAP) in gastric tumor cells. YAP inhibitor verteporfin, similar to OA, downregulated the expression of HIF-1α and glycolytic enzymes in gastric cancer cells; whereas overexpression of YAP abrogated all these effects of OA. Collectively, inhibition of YAP was responsible for OA blockade of HIF-1α-mediated aerobic glycolysis and proliferation in human gastric tumor cells. OA could be developed as a promising candidate for gastric cancer treatment.

Macrophages are essential inflammatory cells which regulate the features of immune reactions within tumors. Many studies have reported their regulatory roles in immunity through cytokines and cell signaling. However, relatively few studies have focused on their metabolic features and mechanisms. We aimed to determine the signaling pathway regulating cell metabolism and the mechanism related to the regulation of human tumor-associated macrophages (TAMs) in gastric cancer (GC). Tumor-infiltrated macrophages were isolated from human GC tissues using magnetic beads, gene transcription was determined by real-time PCR, protein expression was monitored using western blots, metabolites were determined using HPLC, and transcriptional regulation was analyzed by the luciferase-based reporter gene system. A significant decrease in microRNA (miR)-30c and an increase in regulated in development and DNA damage responses 1 (REDD1) were detected in human GC TAMs, the transcription of miR-30c was negatively correlated with REDD1. MicroRNA-30c expression was suppressed by hypoxia-inducible factor-1α activation and related to decreased mTOR activity as well as glycolysis in human GC TAMs. Hypoxia-regulated miR-30c downregulated REDD-1 expression by targeting its 3'UTR. Overexpression of miR-30c or restored mTOR activity in macrophages with miR-30c

BACKGROUND AND PURPOSE: The pathogenesis of endometrial cancer (EC) involves many regulatory pathways including transcriptional regulatory networks supported by transcription factors and microRNAs only in part known. The aim of this retrospective study was to explore the possible correlation in the EC microenvironment between master regulators of complex phenomena such as steroid responsiveness through estrogen receptor alpha (ERα) and progesterone receptor (PR), epithelial-to-mesenchymal transition (supported by SLUG transcription factor), hypoxia (with hypoxia inducible factor-1 alpha, HIF-1α), and obesity that has been recognized as a EC risk factor.
METHODS: Formalin-Fixed Paraffin-Embedded (FFPE) blocks from University of Ferrara Pathology Archive were used and allocated into 2 groups according to their immunohistochemical positivity to ERα and PR, distinguishing the samples with a more benign prognosis (ERα
RESULTS: We showed a comparable percentage of HIF1-α and SLUG positive samples in the ERα
CONCLUSIONS: A molecular circuit of mutual regulation between ERα, PR, HIF1-α, SLUG and miR-221 is feasible in the EC and was firstly suggested by our research. In this interplay miR-221 seems to be in a nodal point of the regulatory system that is particularly strengthened by the metabolic changes in obesity.

The hypoxic microenvironment is one of the major features of solid tumors, which regulates cell malignancy in multiple ways. As a response to hypoxia, a large number of target genes involved in cell growth, metabolism, metastasis and immunity are activated in cancer cells. Hypoxia-inducible factor 1 (HIF-1), as a heterodimeric DNA-binding complex, is comprised of a constitutively expressed HIF-1β subunit and an oxygen sensitive HIF-1α subunit, thus, adapts to decreased oxygen availability as a transcriptional factor. HIF-1 regulates many genes involved in tumorigenesis. Here, we focus on cancer cell metabolism and metastasis regulated by hypoxia.

BACKGROUND/AIM: The aim of the present study was to investigate the vascular normalization effect of traditional Chinese medicine Astragalus membranaceus (AM) and Curcuma wenyujin (CW) on tumor-derived endothelial cells (TECs).
MATERIALS AND METHODS: TECs were isolated from the xenografted HCC cell line HepG2 expressing red fluorescent protein (RFP). The effect of AM and CW on TECs proliferation was measured using the CCK8 assay. The vascular normalization potential of AM and CW was assessed using a tube formation assay. Immunocytochemistry was performed to assess the effect of AM and CW on the expression of angiogenic maker CD34 and hypoxia-inducible factor HIF1a.
RESULTS: The isolated TECs and endothelioma (EOMA) cells did not differ with regard to the expression levels of endothelial markers CD34, VEGFR-1, VEGFR-2, PDGFR-α and PDGFR-β. All AM, CW, AM+CW and Nintedanib (Nin) showed a dose-dependent increasing inhibition effect on either TECs or EOMA cells. AM, CW and AM+CW significantly reduced HIF1a expression, increased CD34 expression and enhanced endothelial network formation in TECs or EOMA cells compared to the control.
CONCLUSION: AM and CW promoted vascular normalization in tumor-derived endothelial cells of HCC, through increased expression of CD34 and reduced expression of HIF1a.

Hypoxia-inducible factor 1α (HIF1α) has been demonstrated to be involved in the resistance of various human cancer cells to chemotherapies. However, the correlation between HIF1α and the sensitivity of human non-small cell lung cancer (NSCLC) cells to cisplatin has not been illuminated. The aim of the present study was to investigate the effects of HIF1α on drug resistance in NSCLC cells. A549 cells were incubated in 21% or 0.5% O2 followed by the assessment of the level of HIF1α with qRT-PCR and western blot and ROS level by DCFH-DA assays. Effects of hypoxia or HIF1α inhibitor LW6 on the proliferation and apoptosis of A549 cells were evaluated via CCK-8 and flow cytometry assays. IC50 of A549 cells to cisplatin was determined by MTT assay. The mitochondrial membrane potential (MMP) was measured via JC-1 staining. Moreover, the expression of apoptosis related protein (Bcl-2, Bax) and drug resistance related proteins (MDR1, MRP1) were measured by western blotting. Exposure of A549 cells to 1% O2 significantly up-regulated HIF1α expression, maintained cell viability to cisplatin but decreased the ROS level, which promoted chemoresistance to cisplatin. LW6-treated A549 cells showed an increase in ROS level that blocked the hypoxia induced resistance to cisplatin and in addition, decreased expression of MDR1 and MRP1 in cisplatin-treated cells. This study revealed that hypoxia-improved cisplatin chemoresistance of NSCLC cells by regulated MDR1 and MRP1 expression via HIF1α/ROS pathway is reversed by LW6, suggesting that LW6 may act as effective sensitizer in chemotherapy for NSCLC.

Drug resistance makes treatment difficult in cancers. The present study identifies and analyzes drug resistance-related miRNA in colorectal cancer. We established 4 types of 5-fluorouracil (5-FU)-resistant colon cancer cell lines in vitro and in vivo. We then analyzed the miRNA expression profile by miRNA array in these 4 cell lines, and identified the drug resistance-related miRNAs. We examined the expression levels of the identified miRNA in 112 colorectal tumor samples from the patients. We identified 12 possible miRNAs involved in 5-FU resistance by miRNA arrays. We then examined the relationship between miR-31, which was the most promising among them, and drug resistance. The ectopic expression of mimic miR-31 showed significant 5-FU resistance in the parental DLD-1 cells, while anti-miR-31 caused significant growth inhibition in DLD/F cells; that is, 5-FU-resistant colon cancer cell line DLD-1 under exposure to 5-FU. When we exposed high doses of 5-FU to parent or 5-FU-resistant cells, the expression levels of miR-31 were raised higher than those of controls. Notably, the expression levels of miR-31 were positively correlated with the grade of clinical stages of colorectal tumors. The protein expression levels of factors inhibiting hypoxia-inducible factor 1 were downregulated by transfection of mimic miR-31 into DLD-1 cells. This study provides evidence supporting the association of miR-31 with 5-FU drug resistance and clinical stages of colorectal tumors.

Extracellular ATP has been shown to play an important role in invasion and the epithelial-mesenchymal transition (EMT) process in breast cancer; however, the mechanism is unclear. Here, by using a cDNA microarray, we demonstrated that extracellular ATP could stimulate hypoxia-inducible factor (HIF) signaling and upregulate hypoxia-inducible factor 1/2α (HIF-1/2α) expression. After knocking down HIF-1/2α using siRNA, we found that ATP-driven invasion and EMT were significantly attenuated via HIF2A-siRNA in breast cancer cells. By using ChIP assays, we revealed that the biological function of extracellular ATP in invasion and EMT process depended on HIF-2α direct targets, among which lysyl oxidase-like 2 (LOXL2) and matrix metalloproteinase-9 (MMP-9) mediated ATP-driven invasion, and E-cadherin and Snail mediated ATP-driven EMT, respectively. In addition, using silver staining and mass spectrometry, we found that phosphoglycerate kinase 1 (PGK1) could interact with HIF-2α and mediate ATP-driven HIF-2α upregulation. Furthermore, we demonstrated that expressions of HIF-2α and its target proteins could be regulated via ATP by AKT-PGK1 pathway. Using a Balb/c mice model, we illustrated the function of HIF-2α in promoting tumor growth and metastasis in vivo. Moreover, by exploring online databases, we found that molecules involved in ATP-HIF-2α signaling were highly expressed in human breast carcinoma tissues and were associated with poor prognosis. Altogether, these findings suggest that extracellular ATP could promote breast carcinoma invasion and EMT via HIF-2α signaling, which may be a potential target for future anti-metastasis therapy.

Hypoxia signaling plays a major role in non-malignant and malignant hyperproliferative diseases. Pulmonary hypertension (PH), a hypoxia-driven vascular disease, is characterized by a glycolytic switch similar to the Warburg effect in cancer. Ras association domain family 1A (RASSF1A) is a scaffold protein that acts as a tumour suppressor. Here we show that hypoxia promotes stabilization of RASSF1A through NOX-1- and protein kinase C- dependent phosphorylation. In parallel, hypoxia inducible factor-1 α (HIF-1α) activates RASSF1A transcription via HIF-binding sites in the RASSF1A promoter region. Vice versa, RASSF1A binds to HIF-1α, blocks its prolyl-hydroxylation and proteasomal degradation, and thus enhances the activation of the glycolytic switch. We find that this mechanism operates in experimental hypoxia-induced PH, which is blocked in RASSF1A knockout mice, in human primary PH vascular cells, and in a subset of human lung cancer cells. We conclude that RASSF1A-HIF-1α forms a feedforward loop driving hypoxia signaling in PH and cancer.

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related deaths. Compound K, an active metabolite of ginsenosides, is reported to exhibit anti-cancer property in various types of human malignancies. The present study investigated the role of compound K on glucose metabolism in NSCLC cells and its underlying mechanism. Our study found that compound K dose-dependently inhibited the cell viability of NSCLC cells. Moreover, administration with compound K decreased glucose uptake and lactate secretion under normoxic and hypoxic conditions. Consistently, the expression of key enzymes (HK II, PDK1 and LDHA) involved in glucose metabolism were inhibited in compound K-treated tumor cells. In addition, compound K inhibited the expression of HIF-1α and its downstream gene GLUT1. On the contrary, overexpression of HIF-1α elevated metabolic reactions and partly attenuated the inhibitory role of compound K on NSCLC cell growth. These results demonstrate that compound K suppresses NSCLC cell growth via HIF-1α mediated metabolic alteration, contributing to novel anticancer therapy by targeting glucose metabolism.

Background: Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor with a pivotal role in physiological and pathological responses to hypoxia. While HIF-1α is known to be involved in hypoxia-induced upregulation of microRNA (miRNA) expression, HIF-1α is also targeted by miRNAs. In this study, miRNAs targeting HIF-1α were identified and their effects on its expression and downstream target genes under hypoxic conditions were investigated. Cell migration under the same conditions was also assessed.
Methods: microRNAs that target
Results: Several of the 19 screened miRNAs considerably decreased the luciferase activity. Transfection with miR-200c had substantial impact on the expression level and transcription activity of HIF-1α. The mRNA level of HIF-1α downstream genes decreased in response to miR-200c overexpression. MiR-200c inhibited cell migration in normoxia and, to a greater extent, in hypoxia. These effects were partly reversed by HIF-1α expression under hypoxic conditions.
Conclusion: miR-200c negatively affects hypoxia-induced responses by downregulating HIF-1α, a key regulator of hypoxia. Therefore, overexpression of miR-200c might have therapeutic potential as an anticancer agent that inhibits tumor hypoxia.

OBJECTIVES: Epigenetic modifiers were important players in the development of haematological malignancies and sensitivity to therapy. Mutations of SET domain-containing 2 (SETD2), a methyltransferase that catalyses the trimethylation of histone 3 on lysine 36 (H3K36me3), were found in various myeloid malignancies. However, the detailed mechanisms through which SETD2 confers chronic myeloid leukaemia progression and resistance to therapy targeting on BCR-ABL remain unclear.
MATERIALS AND METHODS: The level of SETD2 in imatinib-sensitive and imatinib-resistant chronic myeloid leukaemia (CML) cells was examined by immunoblotting and quantitative real-time PCR. We analysed CD34
RESULTS: SETD2 was found to act as a tumour suppressor in CML. The novel oncogenic targets MYCN and ERG were shown to be the direct downstream targets of SETD2, where their overexpression induced by SETD2 knockdown caused imatinib insensitivity and leukaemic stem cell enrichment in CML cell lines. Treatment with JIB-04, an inhibitor that restores H3K36me3 levels through blockade of its demethylation, successfully improved the cell imatinib sensitivity and enhanced the chemotherapeutic effect.
CONCLUSIONS: Our study not only emphasizes the regulatory mechanism of SETD2 in CML, but also provides promising therapeutic strategies for overcoming the imatinib resistance in patients with CML.

The most common and aggressive type of brain cancer in adults is glioblastoma multiforme (GBM), and hypoxia is a common feature of glioblastoma. As the histological features of glioma include capillary endothelial cell proliferation, they are highly prone to invading the surrounding normal brain tissue, which is often one of the reasons for the failure of treatment. However, the mechanisms involved in this process are not fully understood. MicroRNAs (miRs) are a class of non‑coding RNA that are able to inhibit the malignant progression of tumor cells through the regulation of downstream genes. In the present study, the low expression of miR‑576‑3p was detected in glioma samples and hypoxia‑treated glioma cells using a reverse transcription‑quantitative polymerase chain reaction. The present study focused on the effects of miR‑576‑3p on hypoxia‑induced glioma. The results of the functional experiments revealed that the overexpression of miR‑576‑3p significantly inhibited the migration and pro‑angiogenic abilities of the glioma cells under hypoxic conditions (P<0.05) compared with in the lentivirus‑miR‑negative control group. Furthermore, luciferase reporter gene assays were used to validate the hypothesis that miR‑576‑3p interacts with the 3'‑untranslated region of hypoxia‑inducible factor‑1α (HIF‑1α) and induces a reduction in the protein levels of matrix metalloproteinase‑2 and vascular endothelial growth factor. Rescue experiments demonstrated that the restoration of HIF‑1α expression attenuated the effect of miR‑576‑3p on the migration and proangiogenic abilities of glioma cells. In conclusion, the present study confirms that miR‑576‑3p is a novel GBM inhibitor and its inhibition of the migration and proangiogenic capacity of hypoxia‑induced glioma cells is mediated by HIF‑1α.

Activation of transforming growth factor β (TGF-β) combined with persistent hypoxia often affects the tumor microenvironment. Disruption of cadherin/catenin complexes induced by these stimulations yields aberrant extracellular matrix (ECM) production, characteristics of epithelial-mesenchymal transition (EMT). Hypoxia-inducible factors (HIF), the hallmark of the response to hypoxia, play differential roles during development of diseases. Recent studies show that localization of cadherin/catenin complexes at the cell membrane might be tightly regulated by protein phosphatase activity. We aimed to investigate the role of stabilized HIF-1α expression by protein phosphatase activity on dissociation of the E-cadherin/β-catenin complex and aberrant ECM expression in lung cancer cells under stimulation by TGF-β. By using lung cancer cells treated with HIF-1α stabilizers or carrying doxycycline-dependent HIF-1α deletion or point mutants, we investigated the role of stabilized HIF-1α expression on TGF-β-induced EMT in lung cancer cells. Furthermore, the underlying mechanisms were determined by inhibition of protein phosphatase activity. Persistent stimulation by TGF-β and hypoxia induced EMT phenotypes in H358 cells in which stabilized HIF-1α expression was inhibited. Stabilized HIF-1α protein expression inhibited the TGF-β-stimulated appearance of EMT phenotypes across cell types and species, independent of de novo vascular endothelial growth factor A (VEGFA) expression. Inhibition of protein phosphatase 2A activity abrogated the HIF-1α-induced repression of the TGF-β-stimulated appearance of EMT phenotypes. This is the first study to show a direct role of stabilized HIF-1α expression on inhibition of TGF-β-induced EMT phenotypes in lung cancer cells, in part, through protein phosphatase activity.

Background: As a newfound type of non-coding RNA, circular RNAs (circRNAs) are involved in various physiological and pathological processes via regulation of gene expression. Increasing evidence shows that aberrantly expressed circRNAs play a crucial role in the initiation and progression of many tumors. However, the functions of different circRNAs in gliomas remain elusive.
Methods: The levels of circRNAs, miRNAs, and mRNAs were quantified by qPCR. The interaction between circDENND2A and miR-625-5p was determined by luciferase reporter and pull-down assays. The migratory and invasive capabilities of glioma cells were examined by wound healing and Transwell assays. Immunohistochemistry was performed to analyze the HIF1α level in glioma tissues.
Results: We predicted circDENND2A (has_circ_0002142) to be a hypoxia-responsive circRNA in glioma via a bioinformatic analysis. We found that hypoxia induced the expression of circDENND2A, which promoted migration and invasion of glioma cells. To understand the behaviors of circDENND2A in glioma, we studied the putative miRNAs targeted by circDENND2A and identified circDENND2A as an efficient sponge of miR-625-5p in glioma cells. Phenotype experiments verified that circDENND2A was required for the hypoxia-induced migration and invasion of glioma cells and that this occurred by sponging of miR-625-5p. Notably, glioma tissues overexpressing HIF1α exhibited a high expression of circDENND2A as well as a low expression of miR-625-5p. circDENND2A was negatively correlated with miR-625-5p.
Conclusion: circDENND2A is required for the hypoxia-induced malignancy of glioma cells and functions by sponging miR-625-5p.

Angiogenesis is recognized as a sign of cancer and facilitates cancer progression and metastasis. Suppression of angiogenesis is a desirable strategy for gastric cancer (GC) management. In this study, we showed a novel role of gastrin in angiogenesis of GC. We observed that treatment with gastrin 17 (G17) increased the proliferation of AGS cells and enhanced tube formation during normoxia and hypoxia. The expression level of VEGF were increased by G17 treatment as well. Experiments on the mechanism showed that G17 promoted HIF-1α expression, which subsequently enhanced β-catenin nuclear localization and activation of TCF3 and LEF1 and finally resulted in angiogenesis by upregulating VEGF. An in vivo experiment confirmed that G17 enhanced GC cell proliferation and angiogenesis in the resultant tumor. In conclusion, our findings indicate that gastrin promotes angiogenesis via activating HIF-1α/β-catenin/VEGF axis in GC.

Senescence is a stress-responsive cellular program that leads to cell cycle arrest. In cancer cells, senescence has profound implications for tumor aggressiveness and clinical outcome, but the molecular events that provoke cancer cells to undergo senescence remain unclear. Herein, we provide evidence that the histone demethylase LSD1/KDM1A supports the growth of Glioblastoma tumor cells and its inhibition triggers senescence response. LSD1 is a histone modifier that participates in key aspects of gene transcription as well as in the regulation of methylation dynamics of non-histone proteins. We found that down-regulation of LSD1 inhibits Glioblastoma cell growth, impairs mTOR pathway and cell migration and induces senescence. At mechanistic level, we found that LSD1 regulates HIF-1α protein stability. Pharmacological inhibition or siRNA-mediated silencing of LSD1 expression effectively reduces HIF-1α protein levels, which suffices for the induction of senescence. Our findings elucidate a mechanism whereby LSD1 controls senescence in Glioblastoma tumor cells through the regulation of HIF-1α, and we propose the novel defined LSD1/HIF-1α axis as a new target for the therapy of Glioblastoma tumors.

OBJECTIVES: To investigate the role of hypoxia in vasculogenic mimicry (VM) of salivary adenoid cystic carcinoma (SACC) and the underlying mechanism involved.
MATERIALS AND METHODS: Firstly, wound healing, transwell invasion, immunofluorescence and tube formation assays were performed to measure the effect of hypoxia on migration, invasion, EMT and VM of SACC cells, respectively. Then, immunofluorescence and RT-PCR were used to detect the effect of hypoxia on VE-cadherin and VEGFA expression. And pro-vasculogenic mimicry effect of VEGFA was investigated by confocal laser scanning microscopy and Western blot. Moreover, the levels of E-cadherin, N-cadherin, Vimentin, CD44 and ALDH1 were determined by Western blot and immunofluorescence in SACC cells treated by exogenous VEGFA or bevacizumab. Finally, CD31/ PAS staining was performed to observe VM and immunohistochemistry was used to determine the levels of VEGFA and HIF-1α in 95 SACC patients. The relationships between VM and clinicopathological variables, VEGFA or HIF-1α level were analysed.
RESULTS: Hypoxia promoted cell migration, invasion, EMT and VM formation, and enhanced VE-cadherin and VEGFA expression in SACC cells. Further, exogenous VEGFA markedly increased the levels of N-cadherin, Vimentin, CD44 and ALDH1, and inhibited the expression of E-cadherin, while the VEGFA inhibitor reversed these changes. In addition, VM channels existed in 25 of 95 SACC samples, and there was a strong positive correlation between VM and clinic stage, distant metastases, VEGFA and HIF-1α expression.
CONCLUSIONS: VEGFA played an important role in hypoxia-induced VM through regulating EMT and stemness, which may eventually fuel the migration and invasion of SACC.

BACKGROUND: The transcription factor hypoxia inducible factor (HIF) -1 drives tumor growth and metastasis and is associated with poor prognosis in breast cancer. Ascorbate can moderate HIF-1 activity in vitro and is associated with HIF pathway activation in a number of cancer types, but whether tissue ascorbate levels influence the HIF pathway in breast cancer is unknown. In this study we investigated the association between tumor ascorbate levels and HIF-1 activation and patient survival in human breast cancer.
METHODS: In a retrospective analysis of human breast cancer tissue, we analysed primary tumor and adjacent uninvolved tissue from 52 women with invasive ductal carcinoma. We measured HIF-1α, HIF-1 gene targets CAIX, BNIP-3 and VEGF, and ascorbate content. Patient clinical outcomes were evaluated against these parameters.
RESULTS: HIF-1 pathway proteins were upregulated in tumor tissue and increased HIF-1 activation was associated with higher tumor grade and stage, with increased vascular invasion and necrosis, and with decreased disease-free and disease-specific survival. Grade 1 tumors had higher ascorbate levels than did grade 2 or 3 tumors. Higher ascorbate levels were associated with less tumor necrosis, with lower HIF-1 pathway activity and with increased disease-free and disease-specific survival.
CONCLUSIONS: Our findings indicate that there is a direct correlation between intracellular ascorbate levels, activation of the HIF-1 pathway and patient survival in breast cancer. This is consistent with the known capacity of ascorbate to stimulate the activity of the regulatory HIF hydroxylases and suggests that optimisation of tumor ascorbate could have clinical benefit via modulation of the hypoxic response.

Metabolic reprogramming is a hallmark of cancer. Here, we demonstrate that tumour-associated macrophages (TAMs) enhance the aerobic glycolysis and apoptotic resistance of breast cancer cells via the extracellular vesicle (EV) transmission of a myeloid-specific lncRNA, HIF-1α-stabilizing long noncoding RNA (HISLA). Mechanistically, HISLA blocks the interaction of PHD2 and HIF-1α to inhibit the hydroxylation and degradation of HIF-1α. Reciprocally, lactate released from glycolytic tumour cells upregulates HISLA in macrophages, constituting a feed-forward loop between TAMs and tumour cells. Blocking EV-transmitted HISLA inhibits the glycolysis and chemoresistance of breast cancer in vivo. Clinically, HISLA expression in TAMs is associated with glycolysis, poor chemotherapeutic response and shorter survival of patients with breast cancer. Our study highlights the potential of lncRNAs as signal transducers that are transmitted between immune and tumour cells via EVs to promote cancer aerobic glycolysis.

Therapeutic inhibition of hypoxia inducible factor-1α (HIF-1α) action has emerged as a potential approach for managing several diseases including breast cancer (BC). Genistein has been found to exert anti-malignant activity. However, its mechanisms of action remain unknown. Studies indicate that it could act by downregulating HIF-1α. Based on these findings, we investigated whether genistein could reduce HIF-1α in BC cell lines. Furthermore, we performed molecular docking studies to characterize the sites of interaction between genistein and HIF-1α. In the present investigation, we prove, for the first time, that genistein downregulates HIF-1α in BC cells. Molecular docking analysis also revealed that genistein binds to the FIH-1 binding site of HIF-1α protein. These findings thus indicate that genistein and/or HIF-1α antagonists could be a potential treatment for BC.

Hepatocellular carcinoma (HCC) has high recurrence rates even after curative hepatectomy. Drug therapy for recurrence of HCC is still limited; therefore, identifying new therapeutic targets is urgently needed. We searched for genes that would predict HCC recurrence from intrahepatic metastasis in an exhaustive DNA microarray database by searching genes associated with high early recurrence rate and having higher expression in the tumor area compared to background liver. We detected lysyl oxidase (LOX) and validated the clinical significance of LOX in 358 patients who underwent hepatectomy. Expression of LOX was evaluated by qRT- PCR, and immunohistochemical (IHC) staining. High LOX expression group had a significantly higher recurrence rate than the low LOX expression group (2-year recurrence rate was 64.0% vs 24.2%, P < .0001 for IHC) and poorer survival rate (5-year rate was 60.1% vs 86.2%, P < .0001 for IHC). Multivariate analysis showed that high LOX expression was an independent risk factor for early recurrence (IHC: HR, 2.52; P < .0001). Bioinformatic analysis showed that LOX expression was associated with hypoxia-inducible factor-1α (HIF-1α) and the hypoxia cascade, suggesting that HIF-1α or hypoxia regulates LOX expression and induces epithelial-mesenchymal transition (EMT). In vitro, LOX and HIF-1α were involved in migration and invasion capability. High LOX expression is associated with EMT markers and predicts early recurrence and poor survival in patients with HCC. These findings indicate that lysyl oxidase could be a potential therapeutic target for early recurrence of HCC.

AIMS: Identifying alterations in lipid metabolism along gastric adenocarcinoma (GA) tumorigenesis pathways could lead to a new approach for potential diagnosis, efficient prediction and promising therapeutic strategies. This study aimed to identify the possible effect of HIF-1α on FASN and SREBP-1c regulation in GA.
MAIN METHODS: AGS cell line was cultured in normoxic and hypoxic conditions, and HIF-1α, FASN and SREBP-1c gene expression were analyzed by qRT-PCR and Western blot. Serum HIF-1α, FASN and insulin concentration were measured in 112 GA patients and 156 control cases by ELISA, and immunohistochemical method was employed to analyze SREBP-1c expression. Tissue mRNA expression of SREBP-1c, FASN and HIF-1α were determined by qRT-PCR.
KEY FINDINGS: In vitro findings indicate upregulation of HIF-1α, FASN and SREBP-1c gene and protein expression in the hypoxic culture of AGS cells. High circulating levels of HIF-1α and FASN were significantly observed in GA patients compared to the controls. HIF-1α, SREBP-1c and FASN gene expression were higher in GA vs. controls. In addition, SREBP-1c protein level was enhanced in GA tissues compared to controls. Furthermore, elevated serum levels of HIF-1α and FASN and expression of HIF-1α, SREBP-1c and FASN genes were associated with unfavorable clinicopathological features such as diffuse type tumor and poor survival.
SIGNIFICANCE: The results by correlating increased levels of FASN to those of HIF-1α and SREBP-1c are consistent with a possible up-regulation of FASN upon induction of HIF-1α through SREBP-1c.

Background: Bone marrow hypoxia can promote leukemia progression in human cases of acute myeloid leukemia (AML). In addition, low oxygen tension is able to regulate the expression of different genes involved in malignancy. In this study, we hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF-A) genes were assessed as principal regulators of hypoxia in do novo AML patients. Methods: Peripheral blood and bone marrow samples were collected from 57 AML patients and 17 normal control subjects with informed consent. Expression of HIF1α and VEGF-A was then evaluated using quantitative real-time PCR (Q-Real time PCR) and data were analyzed with SPSS 16. Result: HIF1α and VEGF-A showed overexpression in AML patients compared to normal controls (P <0.0001 and P<0.005, respectively). The expression level of HIF1α was significantly higher in AML-M3 cases versus AML-non M3 cases. Furthermore, there was a positive correlation between HIF1α and VEGF-A ( P <0.0001 and r = 0.497). Conclusion: Adding to the many studies on the role of hypoxia in solid tumors, our data indicate that HIF1a and VEGF-A overexpression also occurs in AML patients. We consider that this is possibly involved in leukemic cell growth and therefore could be a promising target for clinical control.

Clear cell renal cell carcinoma (ccRCC) is the most common and lethal form of urological cancer diagnosed globally. Mutations of the von Hippel-Lindau

BACKGROUND: There is significant controversy in the literature regarding the relationship between hypoxia and salivary gland neoplasms (SGNs).
OBJECTIVE: The current study aims to investigate levels of hypoxia markers in both benign and malignant salivary neoplasms.
PATIENTS AND METHODS: The current study sample is comprised of a total of 62 samples. HIF-1α expression was evaluated by immunohistochemistry. Additionally, HIF-1α mRNA and miR-210 levels were assessed using qRT-PCR.
RESULTS: No differences in HIF-1α expression were observed among the control group, benign and malignant SGNs. Similarly, HIF-1α mRNA levels were similar between benign and malignant SGNs. Also, there was no difference in miR-210 expression between case and control groups.
CONCLUSION: The angiogenic markers, miR-210 and HIF-1α, do not appear to distinguish malignancy in salivary glands.

Nearly one-third of patients with high-grade serous ovarian cancer (HGSC) do not respond to initial treatment with platinum-based therapy. Genomic and clinical characterization of these patients may lead to potential alternative therapies. Here, the objective is to classify non-responders into subsets using clinical and molecular features. Using patients from The Cancer Genome Atlas (TCGA) dataset with platinum-resistant or platinum-refractory HGSC, we performed a genome-wide unsupervised cluster analysis that integrated clinical data, gene copy number variations, gene somatic mutations, and DNA promoter methylation. Pathway enrichment analysis was performed for each cluster to identify the targetable processes. Following the unsupervised cluster analysis, three distinct clusters of non-responders emerged. Cluster 1 had overrepresentation of the stage IV disease and suboptimal debulking, under-expression of miRNAs and mRNAs, hypomethylated DNA, "loss of function"

Some driver gene mutations, including epidermal growth factor receptor (EGFR), have been reported to be involved in expression regulation of the immunosuppressive checkpoint protein programmed cell death ligand 1 (PD-L1), but the underlying mechanism remains obscure. We investigated the potential role and precise mechanism of EGFR mutants in PD-L1 expression regulation in non-small-cell lung cancer (NSCLC) cells. Examination of pivotal EGFR signaling effectors in 8 NSCLC cell lines indicated apparent associations between PD-L1 overexpression and phosphorylation of AKT and ERK, especially with increased protein levels of phospho-IκBα (p-IκBα) and hypoxia-inducible factor-1α (HIF-1α). Flow cytometry results showed stronger membrane co-expression of EGFR and PD-L1 in NSCLC cells with EGFR mutants compared with cells carrying WT EGFR. Additionally, ectopic expression or depletion of EGFR mutants and treatment with EGFR pathway inhibitors targeting MEK/ERK, PI3K/AKT, mTOR/S6, IκBα, and HIF-1α indicated strong accordance among protein levels of PD-L1, p-IκBα, and HIF-1α in NSCLC cells. Further treatment with pathway inhibitors significantly inhibited xenograft tumor growth and p-IκBα, HIF-1α, and PD-L1 expression of NSCLC cells carrying EGFR mutant in nude mice. Moreover, immunohistochemical analysis revealed obviously increased protein levels of p-IκBα, HIF-1α, and PD-L1 in NSCLC tissues with EGFR mutants compared with tissues carrying WT EGFR. Non-small-cell lung cancer tissues with either p-IκBα or HIF-1α positive staining were more likely to possess elevated PD-L1 expression compared with tissues scored negative for both p-IκBα and HIF-1α. Our findings showed important roles of phosphorylation activation of AKT and ERK and potential interplay and cooperation between NF-κB and HIF-1α in PD-L1 expression regulation by EGFR mutants in NSCLC.

Since the first identification of hypoxic cells in sections of carcinomas in the 1950s, hypoxia has been known as a central hallmark of cancer cells and their microenvironment. Indeed, hypoxia benefits cancer cells in their growth, survival, and metastasis. The historical discovery of hypoxia-inducible factor-1α (HIF1A) in the early 1990s had a great influence on the field as many phenomena in hypoxia could be explained by HIF1A. However, not all regions or types of tumors are necessarily hypoxic. Thus, it is difficult to explain whole cancer pathobiology by hypoxia, especially in the early stage of cancer. Upregulation of glucose metabolism in cancer cells has been well known. Oxygen-independent glycolysis is activated in cancer cells even in the normoxia condition, which is known as the Warburg effect. Accumulating evidence and recent advances in cancer metabolism research suggest that hypoxia-independent mechanisms for HIF signaling activation is a hallmark for cancer. There are various mechanisms that generate pseudohypoxic conditions, even in normoxia. Given the importance of HIF1A for cancer pathobiology, the pseudohypoxia concept could shed light on the longstanding mystery of the Warburg effect and accelerate better understanding of the diverse phenomena seen in a variety of cancers.