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  1. Associations between hypoxia-inducible factor-1alpha (HIF-1alpha) gene polymorphisms and risk of developing breast cancer
    Naidu R, Har YC, Taib NA
    Neoplasma, 2009;56(5):441-7.
    PMID: 19580347
    The C1772T, G1790A and C111A polymorphisms of Hypoxia-inducible factor-1alpha (HIF-1alpha) gene were analyzed in a hospital-based Malaysian population using PCR-RFLP method. Genomic DNA was extracted from the blood samples collected from 410 breast cancer patients and 275 normal and healthy women. We investigated the association between HIF-1alpha polymorphisms and breast cancer risk, and clinico-pathological parameters in the population. The genotype and allele frequencies of C1772T (P=0.0093 vs P=0.0024) polymorphism were significantly different between the breast cancer cases and normal subjects but similar association was not observed for G1790A (P>0.05) and C111A (P>0.05) polymorphisms, respectively. Women who were CT heterozygotes (OR=1.51; 95% CI, 1.01-2.25), TT homozygotes (OR=4.03; 95% CI, 1.09-17.60) and carriers of T allele genotype (OR=1.65; 95% CI, 1.13-2.43) were significantly associated with increased risk of breast cancer. Significant relationship was observed also between T allele and breast cancer risk (OR=1.69; 95% CI, 1.20-2.40). Clinico-pathological analysis showed that 1772T allele genotype was significantly associated with nodal metastases (P=0.0478) but independent of ER status, tumor grade and patients' age (P>0.05). Our observations suggest that the polymorphic allele of C1772T may be associated with increased risk of developing breast cancer, and presence of 1772T allele may be a useful genetic marker for tumor prognosis.
    Matched MeSH terms: Hypoxia-Inducible Factor 1, alpha Subunit/genetics*
  2. Fulltext [Zinc induces normoxic accumulation of transcriptionally active hypoxia-inducible factor 1-alpha in mammary epithelial cells]
    Lee SY, Mustafa S, Ching YW, Shafee N
    Mol Biol (Mosk), 2017 3 3;51(1):104-110.
    PMID: 28251972 DOI: 10.7868/S0026898417010116
    Both zinc and the α-subunit of hypoxia-inducible factor (HIF-1α) play important roles in the remodelling of mammary gland tissues. In the present study, we examined the level and the transcriptional activity of HIF-1α in mammary cells upon zinc treatment. In MCF-7 mammary adenocarcinoma and MCF-10A mammary epithelial cell lines, the toxicity levels of zinc differ. Interestingly, both cell lines overexpress HIF-1α following zinc treatment. As it was evident from an up-regulation of its specific target gene CA9 that encodes carbonic anhydrase IX, the stabilized HIF-1α translocated to the nucleus and was transcriptionally active. Hence, we conclude that zinc causes normoxic accumulation of transcriptionally active HIF-1α by interfering with its post-translational regulation.
    Matched MeSH terms: Hypoxia-Inducible Factor 1, alpha Subunit/genetics
  3. Impact of low oxygen tension on stemness, proliferation and differentiation potential of human adipose-derived stem cells
    Choi JR, Pingguan-Murphy B, Wan Abas WA, Noor Azmi MA, Omar SZ, Chua KH, et al.
    Biochem Biophys Res Commun, 2014 May 30;448(2):218-24.
    PMID: 24785372 DOI: 10.1016/j.bbrc.2014.04.096
    Adipose-derived stem cells (ASCs) have been found adapted to a specific niche with low oxygen tension (hypoxia) in the body. As an important component of this niche, oxygen tension has been known to play a critical role in the maintenance of stem cell characteristics. However, the effect of O2 tension on their functional properties has not been well determined. In this study, we investigated the effects of O2 tension on ASCs stemness, differentiation and proliferation ability. Human ASCs were cultured under normoxia (21% O2) and hypoxia (2% O2). We found that hypoxia increased ASC stemness marker expression and proliferation rate without altering their morphology and surface markers. Low oxygen tension further enhances the chondrogenic differentiation ability, but reduces both adipogenic and osteogenic differentiation potential. These results might be correlated with the increased expression of HIF-1α under hypoxia. Taken together, we suggest that growing ASCs under 2% O2 tension may be important in expanding ASCs effectively while maintaining their functional properties for clinical therapy, particularly for the treatment of cartilage defects.
    Matched MeSH terms: Hypoxia-Inducible Factor 1, alpha Subunit/genetics
  4. Fulltext Quantitative MS-Based Proteomics: Comparing the MCF-7 Cellular Response to Hypoxia and a 2-Oxoglutarate Analogue
    Bush JT, Chan MC, Mohammed S, Schofield CJ
    Chembiochem, 2020 06 02;21(11):1647-1655.
    PMID: 31919953 DOI: 10.1002/cbic.201900719
    The hypoxia-inducible factors (HIFs) are key transcription factors in determining cellular responses involving alterations in protein levels in response to limited oxygen availability in animal cells. 2-Oxoglutarate-dependent oxygenases play key roles in regulating levels of HIF and its transcriptional activity. We describe MS-based proteomics studies in which we compared the results of subjecting human breast cancer MCF-7 cells to hypoxia or treating them with a cell-penetrating derivative (dimethyl N-oxalylglycine; DMOG) of the stable 2OG analogue N-oxalylglycine. The proteomic results are consistent with reported transcriptomic analyses and support the proposed key roles of 2OG-dependent HIF prolyl- and asparaginyl-hydroxylases in the hypoxic response. Differences between the data sets for hypoxia and DMOG might reflect context-dependent effects or HIF-independent effects of DMOG.
    Matched MeSH terms: Hypoxia-Inducible Factor 1, alpha Subunit/genetics*
  5. Fulltext Inhibition of Raf-MEK-ERK and hypoxia pathways by Phyllanthus prevents metastasis in human lung (A549) cancer cell line
    Lee SH, Jaganath IB, Manikam R, Sekaran SD
    BMC Complement Altern Med, 2013 Oct 20;13:271.
    PMID: 24138815 DOI: 10.1186/1472-6882-13-271
    BACKGROUND: Lung cancer constitutes one of the malignancies with the greatest incidence and mortality rates with 1.6 million new cases and 1.4 million deaths each year. Prognosis remains poor due to deleterious development of multidrug resistance resulting in less than 15% lung cancer patients reaching five years survival. We have previously shown that Phyllanthus induced apoptosis in conjunction with its antimetastastic action. In the current study, we aimed to determine the signaling pathways utilized by Phyllanthus to exert its antimetastatic activities.

    METHODS: Cancer 10-pathway reporter array was performed to screen the pathways affected by Phyllanthus in lung carcinoma cell line (A549) to exert its antimetastatic effects. Results from this array were then confirmed with western blotting, cell cycle analysis, zymography technique, and cell based ELISA assay for human total iNOS. Two-dimensional gel electrophoresis was subsequently carried out to study the differential protein expressions in A549 after treatment with Phyllanthus.

    RESULTS: Phyllanthus was observed to cause antimetastatic activities by inhibiting ERK1/2 pathway via suppression of Raf protein. Inhibition of this pathway resulted in the suppression of MMP2, MMP7, and MMP9 expression to stop A549 metastasis. Phyllanthus also inhibits hypoxia pathway via inhibition of HIF-1α that led to reduced VEGF and iNOS expressions. Proteomic analysis revealed a number of proteins downregulated by Phyllanthus that were involved in metastatic processes, including invasion and mobility proteins (cytoskeletal proteins), transcriptional proteins (proliferating cell nuclear antigen; zinc finger protein), antiapoptotic protein (Bcl2) and various glycolytic enzymes. Among the four Phyllanthus species tested, P. urinaria showed the greatest antimetastatic activity.

    CONCLUSIONS: Phyllanthus inhibits A549 metastasis by suppressing ERK1/2 and hypoxia pathways that led to suppression of various critical proteins for A549 invasion and migration.

    Matched MeSH terms: Hypoxia-Inducible Factor 1, alpha Subunit/genetics
  6. Fulltext PI3K/Akt activity has variable cell-specific effects on expression of HIF target genes, CA9 and VEGF, in human cancer cell lines
    Shafee N, Kaluz S, Ru N, Stanbridge EJ
    Cancer Lett, 2009 Sep 8;282(1):109-15.
    PMID: 19342157 DOI: 10.1016/j.canlet.2009.03.004
    The phosphatidylinositol 3-kinase/Akt (PI3K) pathway regulates hypoxia-inducible factor (HIF) activity. Higher expression of HIF-1alpha and carbonic anhydrase IX (CAIX), a hypoxia-inducible gene, in HT10806TG fibrosarcoma cells (mutant N-ras allele), compared to derivative MCH603 cells (deleted mutant N-ras allele), correlated with increased PI3K activity. Constitutive activation of the PI3K pathway in MCH603/PI3K(act) cells increased HIF-1alpha but, surprisingly, decreased CAIX levels. The cell-type specific inhibitory effect on CAIX was confirmed at the transcriptional level whereas epigenetic modifications of CA9 were ruled out. In summary, our data do not substantiate the generalization that PI3K upregulation leads to increased HIF activity.
    Matched MeSH terms: Hypoxia-Inducible Factor 1, alpha Subunit/genetics*
  7. Fulltext Newcastle disease virus degrades HIF-1α through proteasomal pathways independent of VHL and p53
    Abd-Aziz N, Stanbridge EJ, Shafee N
    J Gen Virol, 2016 Dec;97(12):3174-3182.
    PMID: 27902314 DOI: 10.1099/jgv.0.000623
    Newcastle disease virus (NDV) is a candidate agent for oncolytic virotherapy. Despite its potential, the exact mechanism of its oncolysis is still not known. Recently, we reported that NDV exhibited an increased oncolytic activity in hypoxic cancer cells. These types of cells negatively affect therapeutic outcome by overexpressing pro-survival genes under the control of the hypoxia-inducible factor (HIF). HIF-1 is a heterodimeric transcriptional factor consisting of a regulated α (HIF-1α) and a constitutive β subunit (HIF-1β). To investigate the effects of NDV infection on HIF-1α in cancer cells, the osteosarcoma (Saos-2), breast carcinoma (MCF-7), colon carcinoma (HCT116) and fibrosarcoma (HT1080) cell lines were used in the present study. Data obtained showed that a velogenic NDV infection diminished hypoxia-induced HIF-1α accumulation, leading to a decreased activation of its downstream target gene, carbonic anhydrase 9. This NDV-induced downregulation of HIF-1α occurred post-translationally and was partially abrogated by proteasomal inhibition. The process appeared to be independent of the tumour suppressor protein p53. These data revealed a correlation between NDV infection and HIF-1α downregulation, which highlights NDV as a promising agent to eliminate hypoxic cancer cells.
    Matched MeSH terms: Hypoxia-Inducible Factor 1, alpha Subunit/genetics
  8. Fulltext High throughput silencing identifies novel genes in endometrioid endometrial cancer
    Md Fuzi AA, Omar SZ, Mohamed Z, Mat Adenan NA, Mokhtar NM
    Taiwan J Obstet Gynecol, 2018 Apr;57(2):217-226.
    PMID: 29673664 DOI: 10.1016/j.tjog.2018.02.009
    OBJECTIVE: To validate the gene expression profile obtained from the previous microarray analysis and to further study the biological functions of these genes in endometrial cancer. From our previous study, we identified 621 differentially expressed genes in laser-captured microdissected endometrioid endometrial cancer as compared to normal endometrial cells. Among these genes, 146 were significantly up-regulated in endometrial cancer.

    MATERIALS AND METHODS: A total of 20 genes were selected from the list of up-regulated genes for the validation assay. The qPCR confirmed that 19 out of the 20 genes were up-regulated in endometrial cancer compared with normal endometrium. RNA interference (RNAi) was used to knockdown the expression of the upregulated genes in ECC-1 and HEC-1A endometrial cancer cell lines and its effect on proliferation, migration and invasion were examined.

    RESULTS: Knockdown of MIF, SOD2, HIF1A and SLC7A5 by RNAi significantly decreased the proliferation of ECC-1 cells (p < 0.05). Our results also showed that the knockdown of MIF, SOD2 and SLC7A5 by RNAi significantly decreased the proliferation and migration abilities of HEC-1A cells (p < 0.05). Moreover, the knockdown of SLC38A1 and HIF1A by RNAi resulted in a significant decrease in the proliferation of HEC1A cells (p < 0.05).

    CONCLUSION: We have identified the biological roles of SLC38A1, MIF, SOD2, HIF1A and SLC7A5 in endometrial cancer, which opens up the possibility of using the RNAi silencing approach to design therapeutic strategies for treatment of endometrial cancer.

    Matched MeSH terms: Hypoxia-Inducible Factor 1, alpha Subunit/genetics
  9. Mesua ferrea stem bark extract induces apoptosis and inhibits metastasis in human colorectal carcinoma HCT 116 cells, through modulation of multiple cell signalling pathways
    Asif M, Shafaei A, Abdul Majid AS, Ezzat MO, Dahham SS, Ahamed MBK, et al.
    Chin J Nat Med, 2017 Jul;15(7):505-514.
    PMID: 28807224 DOI: 10.1016/S1875-5364(17)30076-6
    Considering the great potential of natural products as anticancer agents, the present study was designed to explore the molecular mechanisms responsible for anticancer activities of Mesua ferrea stem bark extract against human colorectal carcinoma. Based on MTT assay results, bioactive sub-fraction (SF-3) was selected for further studies using HCT 116 cells. Repeated column chromatography resulted in isolation of less active α-amyrin from SF-3, which was identified and characterized by GC-MS and HPLC methods. α-amyrin and betulinic acid contents of SF-3 were measured by HPLC methods. Fluorescent assays revealed characteristic apoptotic features, including cell shrinkage, nuclear condensation, and marked decrease in mitochondrial membrane potential in SF-3 treated cells. In addition, increased levels of caspases-9 and -3/7 levels were also observed in SF-3 treated cells. SF-3 showed promising antimetastatic properties in multiple in vitro assays. Multi-pathway analysis revealed significant down-regulation of WNT, HIF-1α, and EGFR with simultaneous up-regulation of p53, Myc/Max, and TGF-β signalling pathways in SF-3 treated cells. In addition, promising growth inhibitory effects were observed in SF-3 treated HCT 116 tumour spheroids, which give a hint about in vivo antitumor efficacy of SF-3 phytoconstituents. In conclusion, these results demonstrated that anticancer effects of SF-3 towards colon cancer are through modulation of multiple molecular pathways.
    Matched MeSH terms: Hypoxia-Inducible Factor 1, alpha Subunit/genetics
  10. Fulltext Deferoxamine preconditioning to restore impaired HIF-1α-mediated angiogenic mechanisms in adipose-derived stem cells from STZ-induced type 1 diabetic rats
    Mehrabani M, Najafi M, Kamarul T, Mansouri K, Iranpour M, Nematollahi MH, et al.
    Cell Prolif, 2015 Oct;48(5):532-49.
    PMID: 26332145 DOI: 10.1111/cpr.12209
    OBJECTIVES: Both excessive and insufficient angiogenesis are associated with progression of diabetic complications, of which poor angiogenesis is an important feature. Currently, adipose-derived stem cells (ADSCs) are considered to be a promising source to aid therapeutic neovascularization. However, functionality of these cells is impaired by diabetes which can result from a defect in hypoxia-inducible factor-1 (HIF-1), a key mediator involved in neovascularization. In the current study, we sought to explore effectiveness of pharmacological priming with deferoxamine (DFO) as a hypoxia mimetic agent, to restore the compromised angiogenic pathway, with the aid of ADSCs derived from streptozotocin (STZ)-induced type 1 diabetic rats ('diabetic ADSCs').

    MATERIALS AND METHODS: Diabetic ADSCs were treated with DFO and compared to normal and non-treated diabetic ADSCs for expression of HIF-1α, VEGF, FGF-2 and SDF-1, at mRNA and protein levels, using qRT-PCR, western blotting and ELISA assay. Activity of matrix metalloproteinases -2 and -9 were measured using a gelatin zymography assay. Angiogenic potential of conditioned media derived from normal, DFO-treated and non-treated diabetic ADSCs were determined by in vitro (in HUVECs) and in vivo experiments including scratch assay, three-dimensional tube formation testing and surgical wound healing models.

    RESULTS: DFO remarkably enhanced expression of noted genes by mRNA and protein levels and restored activity of matrix metalloproteinases -2 and -9. Compromised angiogenic potential of conditioned medium derived from diabetic ADSCs was restored by DFO both in vitro and in vivo experiments.

    CONCLUSION: DFO preconditioning restored neovascularization potential of ADSCs derived from diabetic rats by affecting the HIF-1α pathway.

    Matched MeSH terms: Hypoxia-Inducible Factor 1, alpha Subunit/genetics
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