Protective effects of piperine on the retina of mice with streptozotocin-induced diabetes by suppressing HIF-1/VEGFA pathway and promoting PEDF expression

AIM:To evaluate the protective mechanisms of piperine in the retina of mice with streptozotocin-induced diabetes.METHODS:In experiments in vitro,stimulation by chemical hypoxia was established in ARPE-19 cells.Then,the expression of hypoxia-inducible factor-1α(HIF-1α),vascular endothelial growth factor A(VEGFA),and pigment epithelium-derived factor(PEDF)was assessed at the m RNA and protein levels.In experiments in vivo,diabetes mellitus was established by intraperitoneally injecting 150 mg/kg streptozotocin once.After 3 wk of the onset of diabetes,15 mg/kg piperine was intraperitoneally injected once daily for 1 or 3 wk.Then,the retinal morphology and m RNA and protein expression were assessed.RESULTS:In hypoxia,1-100μmol/L piperine significantly decreased the expression of VEGFA m RNA and increased the expression of PEDF m RNA without affecting HIF-1αm RNA.Meanwhile,100μmol/L piperine substantially decreased the protein level of VEGFA and increased the protein level of PEDF.The HIF-1αprotein level was also hampered by piperine.In the diabetic retina of mice,the morphological damage was alleviated by piperine.Likewise,the retinal vascular leakage was substantially decreased by piperine.Further,the protein levels of HIF-1αand VEGFA were significantly reduced by piperine.Moreover,the level of the antiangiogenic factor of PEDF dramatically increased by piperine.CONCLUSION:Piperine may exert protective effects on the retina of mice with diabetes via regulating the pro-antiangiogenic homeostasis composed of HIF-1/VEGFA and PEDF.

急性脑出血患者血清HIF-1α与VEGF、Hsp70动态表达情况研究

目的:研究分析急性脑出血患者血清低氧诱导因子(hypoxia-inducible factor-1α,HIF-1α)与血管生长因子(vascular endothelial growth factor,VEGF)、热休克蛋白70(heat shock protein 70,Hsp70)动态表达情况。方法:将2014年3月至2015年4月我院急诊收治的35例急性脑出血患者,根据其出血量分为小量组、中量组、大量组,测定比较各分组人员发病后12 h、1 d、3 d、5 d、7 d的静脉血HIF-1α与VEGF、Hsp70差异,同时研究分析这3者与出血量之间的相关关系。结果:大量组患者不同时间点HIF-1α与VEGF、Hsp70指标均明显高于同时间点其他两组患者,P<0.05;单因素方差分析HIF-1α与VEGF、Hsp70与患者出血量间关系,均成正相关(r=0.563,P<0.05;r=0.771,P<0.05;r=0.602,P<0.05)。结论:HIF-1α、VEGF、Hsp70在急性脑出血患者中表达较高,在脑出血12 h后升高,并随着脑出血的发展呈现动态表达,且与出血量成正相关关系。

Clinicopathological features of hypoxia-inducible factor-1α and vascular endothelial growth factor expression in patients with lung cancer

Objective The aim of the study was to investigate the clinicopathological characteristics of hypoxiainducible factor-1α(HIF-1α) and vascular endothelial growth factor(VEGF) expression in patients with lung cancer.Methods Cancerous and noncancerous tissues were collected post-operation from 115 patients with lung cancers by the self-control method. Total RNA was extracted from the lung tissues. The status of tissue HIF-1α expression and intercellular distribution was observed by immunochemistry using a tissue microarray. The expression levels of circulating HIF-1α and VEGF were detected by enzyme-linked immunosorbent assay(ELISA).Results The expression of serum HIF-1α [(138.3 ± 28.8) μg/L] in the group of patients with lung cancer was significantly higher(P < 0.01) than that in the group of patients with pneumonia [(58.8 ± 14.5) μg/L] and the control group of patients ((24.1 ± 3.3) μg/L)There was a strong positive correlation of serum HIF-1α levels(r = 0.937, P < 0.01) with serum VEGF levels. The specific concentration of total RNA [(1.52 ± 1.14) μg/mg wet lung tissues] in the cancerous tissues was significantly higher(t = 8.494, P < 0.001) than that in the noncancerous tissues ((0.58 ± 0.33) μg/mg)The clinicopathological features of HIF-1α expression in lung cancer tissues revealed a significant relationship between positive HIF-1α expression and patient sex(χ~2 = 4.494, P = 0.034), tumor size(χ~2 = 4.679, P = 0.031), differentiation degree(χ~2= 8.846, P = 0.012), and presence of lymphatic node metastasis(χ~2= 6.604, P = 0.037).Conclusion Abnormal HIF-1α expression in lung cancer is closely related with nucleic acid metabolism and angiogenesis, and it may be helpful in the diagnosis and identification of lung cancer.

Regulation of HIF-1 α to Expression of N-myc Downstream Regulated Gene 1 in Colorectal Carcinoma

Plasmid expressing small interfering RNA （siRNA） against HIF-1α （pSilence-2.1-U6-siRNA） was constructed and transfected into LS174T cells in hypoxia condition.After expression of siRNA against HIF-1 α in LS174T cells, expressions of HIF-1 α and N-myc downstream regulated gene 1 （NDRG1） gene were inhibited significantly. HIF-1 cta transcripts were positive in 67.7% （42/62） and 44.4% （8/18） of colorectal adenocarcinoma and adenoma, re- spectively. The mean percentage of cells with positive hybridization of HIF-1 α mRNA increases with the development from Duke stage A to stage C＋D （p〈 0.05）. The positive staining rate of NDRG1 protein was significant higher in than that in colorectal adenoma colorectal adenocarcinoma group group （p〈 0.05）. The level of HIF-1 a transcripts was positively correlated with the level of NDRG1 protein （p 〈 0.05） during colorectal tumor progression. HIF-1α and its down stream gene NDRG1 may play roles in tumor progression of human colorectal carcinoma.

Abnormal expression of hypoxia inducible factor-1α and clinical values of molecular-targeted interference in hepatocellular carcinoma

Objective:The aim of this study was to analyze the expression features of hypoxia inducible factor-1α (HIF-1α) in hepatocellular carcinoma (HCC) and effects of HIF-1α silencing on HepG2 cells.Methods:HIF-1α expression was analyzed in the self-control HCC specimens by immunohistochemistry.After HepG2 cells with miRNA transfection,the expression of HIF-1α was determined at mRNA or protein level by real-time polymerase chain reaction (PCR) or Western blotting.Vascular endothelial growth factor (VEGF) and angiopoietin-2 (ANG-2) were determined by ELISA.Alterations of cell cycles and apoptosis of HepG2 cells were measured using a flow cytometer.Results:Positive HIF-1α was brown and granule-like in the cytoplasm or nucleus.Significant difference was found between HCC (80%) and its surrounding tissues (100%,χ2=22.35,P < 0.001) and HIF-1α expression related to tumor size.At 72 h after miRNA transfection,the expression of HIF-1α in HepG2 cells was down-regulated by 87% at mRNA or 65% at protein level,with VEGF and ANG-2 decreased to 54% and 36%,respectively.After RNA interference combined with anti-cancer drug,the apoptotic rate of HepG2 cells was increasing from 22.46% ± 0.61% to 36.99% ± 0.88%,with up-regulation of G1 phase (65.68% ± 0.91%) and down-regulation of S phase (19.47 ± 1.34 %).Conclusion:Abnormal expression of HIF-1α is associated with development of HCC,and HIF-1α gene silencing can effectively inhibit HepG2 cell proliferation.

Endostar enhances anti-tumor effects of radiation via inhibition of HIF-1α and bFGF in lung adenocarcinoma cell line A549

Objective： The aim of the study was to investigate whether enhanced anti-tumor effects of endostar （ES） on radiation involved hypoxia inducible factor-la （HIF-la） and basic ~broblast growth factor （bFGF）. Methods： A549 cells were divided into four groups： control group; endostar （ES） group; radiation （RT） group; endostar plus radiation （ES ＋ RT） group. The inhibition of proliferation rates ofA549 cells was measured by cell counting kit-8 （CCK-8）. HIF-la and bFGF expression levels were checked by enzyme linked immunosorbent assay （ELISA） and reverse transcription-polymerase chain reaction （RT-PCR）. Results： The proliferation inhibition rate in the ES ＋ RT group was higher than that in other groups. On the other hand, the expressions of HIF-1α and bFGF in the ES ＋ RT group were significantly reduced compared to other groups. HIF-1α and bFGF levels were positively correlated （r = 0.80, P 〈 0.01）. Conclusion： Our results suggest that endostar could enhance anti-tumor effect of radiation by reducing expressions of HIF-1α and bFGF.

HIF-1α signaling: Essential roles in tumorigenesis and implications in targeted therapies

The hypoxic microenvironment is an essential characteristic of most malignant tu-mors.Notably,hypoxia-inducible factor-1 alpha(HIF-1a)is a key regulatory factor of cellular adaptation to hypoxia,and many critical pathways are correlated with the biological activity of organisms via HIF-1a.In the intra-tumoral hypoxic environment,HIF-1αis highly expressed and contributes to the malignant progression of tumors,which in turn results in a poor prog-nosis in patients.Recently,it has been indicated that HiF-1αinvolves in various critical pro-cesses of life events and tumor development via regulating the expression of HiF-1a target genes,such as cell proliferation and apoptosis,angiogenesis,glucose metabolism,immune response,therapeutic resistance,etc.Apart from solid tumors,accumulating evidence has re-vealed that HiF-1αis also closely associated with the development and progression of hemato-logical malignancies,such as leukemia,lymphoma,and multiple myeloma.Targeted inhibition of HiF-1a can facilitate an increased sensitivity of patients with malignancies to relevant ther-apeutic agents.In the review,we elaborated on the basic structure and biological functions of HIF-1a and summarized their current role in various malignancies.It is expected that they will have future potential fortargeted therapy.

Hypoxia-induced ROS aggravate tumor progression through HIF-1α-SERPINE1 signaling in glioblastoma

Hypoxia,as an important hallmark of the tumor microenvironment,is a major cause of oxidative stress and plays a central role in various malignant tumors,including glioblastoma.Elevated reactive oxygen species(ROS)in a hypoxic microenvironment promote glioblastoma progression;however,the underlying mechanism has not been clarified.Herein,we found that hypoxia promoted ROS production,and the proliferation,migration,and invasion of glioblastoma cells,while this promotion was restrained by ROS scavengers N-acetyl-L-cysteine(NAC)and diphenyleneiodonium chloride(DPI).Hypoxia-induced ROS activated hypoxia-inducible factor-1α(HIF-1α)signaling,which enhanced cell migration and invasion by epithelial-mesenchymal transition(EMT).Furthermore,the induction of serine protease inhibitor family E member 1(SERPINE1)was ROS-dependent under hypoxia,and HIF-1αmediated SERPINE1 increase induced by ROS via binding to the SERPINE1 promoter region,thereby facilitating glioblastoma migration and invasion.Taken together,our data revealed that hypoxia-induced ROS reinforce the hypoxic adaptation of glioblastoma by driving the HIF-1α-SERPINE1 signaling pathway,and that targeting ROS may be a promising therapeutic strategy for glioblastoma.

Transition of autophagy and apoptosis in fibroblasts depends on dominant expression of HIF-1αor p53

It has been revealed that hypoxia is dynamic in hypertrophic scars;therefore,we considered that it may have different effects on hypoxia-inducible factor-1α(HIF-1α)and p53 expression.Herein,we aimed to confirm the presence of a teeterboard-like conversion between HIF-1αand p53,which is correlated with scar formation and regression.Thus,we obtained samples of normal skin and hypertrophic scars to identify the differences in HIF-1αand autophagy using immunohistochemistry and transmission electron microscopy.In addition,we used moderate hypoxia in vitro to simulate the proliferative scar,and silenced HIF-1αor p53 gene expression or triggered overexpression to investigate the changes of HIF-1αand p53 expression,autophagy,apoptosis,and cell proliferation under this condition.HIF-1α,p53,and autophagy-related proteins were assayed using western blotting and immunofluorescence,whereas apoptosis was detected using flow cytometry analysis,and cell proliferation was detected using cell counting kit-8(CCK-8)and 5-bromo-2′-deoxyuridine(BrdU)staining.Furthermore,immunoprecipitation was performed to verify the binding of HIF-1αand p53 to transcription cofactor p300.Our results demonstrated that,in scar tissue,HIF-1αexpression increased in parallel with autophagosome formation.Under hypoxia,HIF-1αexpression and autophagy were upregulated,whereas p53 expression and apoptosis were downregulated in vitro.HIF-1αknockdown downregulated autophagy,proliferation,and p300-bound HIF-1α,and upregulated p53 expression,apoptosis,and p300-bound p53.Meanwhile,p53 knockdown induced the opposite effects and enhanced HIF-1α,whereas p53 overexpression resulted in the same effects and reduced HIF-1α.Our results suggest a teeterboard-like conversion between HIF-1αand p53,which is linked with scar hyperplasia and regression.

Ursolic acid sensitized colon cancer cells to chemotherapy under hypoxia by inhibiting MDR1 through HIF-1α

Objective： To explore the efficacy of ursolic acid in sensitizing colon cancer cells to chemotherapy under hypoxia and its underlying mechanisms. Methods： Three colon cancer cell lines （RKO, LoVo, and SW480） were used as in vitro models. 5-Fluorouracil （5-FU） and oxaliplatin were used as chemotherapeutic drugs. Cell viability and apoptosis were tested to evaluate the sensitivity of colon cancer cells to chemotherapy. The transcription and ex- pression levels of hypoxia-inducible factor-1α （HIF-1α）, multidrug resistance gene 1 （MDR1）, and vascular endothelial growth factors （VEGF） were assessed by quantitative real-time polymerase chain reaction （qRT-PCR） and im- munoblotting. Cycloheximide and MG132 were used to inhibit protein synthesis and degradation, respectively. In vitro tube formation assay was used to evaluate angiogenesis. Results： We demonstrated the chemosensitizing effects of ursolic acid with 5-FU and oxaliplatin in three colon cancer cell lines under hypoxia. This effect was correlated to its inhibition of MDR1 through HIF-la. Moreover, ursolic acid was capable of inhibiting HIF-1α accumulation with little effects on its constitutional expression in normoxia. In addition, ursolic acid also down-regulated VEGF and inhibited tumor angiogenesis. Conclusions： Ursolic acid exerted chemosensitizing effects in colon cancer cells under hypoxia by inhibiting HIF-la accumulation and the subsequent expression of the MDR1 and VEGF.

Targeting TRMT5 suppresses hepatocellular carcinoma progression via inhibiting the HIF-1αpathways

Accumulating evidence has confirmed the links between transfer RNA(tRNA)modifications and tumor progression.The present study is the first to explore the role of tRNA methyltransferase 5(TRMT5),which catalyzes the m1G37 modification of mitochondrial tRNAs in hepatocellular carcinoma(HCC)progression.Here,based on bioinformatics and clinical analyses,we identified that TRMT5 expression was upregulated in HCC,which correlated with poor prognosis.Silencing TRMT5 attenuated HCC proliferation and metastasis both in vivo and in vitro,which may be partially explained by declined extracellular acidification rate(ECAR)and oxygen consumption rate(OCR).Mechanistically,we discovered that knockdown of TRMT5 inactivated the hypoxia-inducible factor-1(HIF-1)signaling pathway by preventing HIF-1αstability through the enhancement of cellular oxygen content.Moreover,our data indicated that inhibition of TRMT5 sensitized HCC to doxorubicin by adjusting HIF-1α.In conclusion,our study revealed that targeting TRMT5 could inhibit HCC progression and increase the susceptibility of tumor cells to chemotherapy drugs.Thus,TRMT5 might be a carcinogenesis candidate gene that could serve as a potential target for HCC therapy.

All-trans retinoic acid upregulates VEGF expression in glioma cells in vitro

All-trans retinoid acid （ATRA） is one of the most potent and most thoroughly studied differentiation inducers that induce the differentiation and apoptosis of glioma cells. However, the effect of ATRA on angiogenesis of glioma re- mains poorly understood. We examined the effect of ATRA on the expression of vascular endothelial growth fac- tor （VEGF） in different glioma cell lines and investigated the underlying mechanism, intending to partially reveal the effects of ATRA on angiogenesis of glioma. Glioma cells were treated by ATRA at 5 and 10 μmol/L. The VEGF mRNA transcript levels were determined by real-time RT-PCR and the protein levels of VEGF in glioma cells were evaluated by Western blotting assays. Moreover, hypoxia-inducible factor-1α （HIF-la） mRNA expression was analyzed by using real-time RT-PCR. After treatment with 5 and 10 μmol/L ATRA, the VEGF mRNA tran- script levels in glioma cells increased remarkably, compared with that in the control group, and the relative protein expression of VEGF was also up-regulated. Meanwhile, the HIF-la mRNA expression also increased. ATRA in- creases the expression of VEGF in glioma cells at both transcriptional and translational levels.

缺氧激活前药evofosfamide(TH-302)在体内和体外对鼻咽癌的疗效

背景与目的肿瘤缺氧被认为是肿瘤转移和疾病复发的重要因素。Evofosfamide是一种缺氧激活前药,可选择性地靶向实体瘤的缺氧区域。由于缺氧诱导因子?1α(hypoxia?inducible factor?1α,HIF?1α)在鼻咽癌(nasopharyngeal carcinoma,NPC)组织中高表达,本研究探讨了evofosfamide在鼻咽癌中的疗效。方法我们评估了evofosfamide作为单药或联合顺铂(DDP)在NPC细胞系CNE?2、HONE?1和HNE?1以及裸鼠异种移植瘤模型中的疗效。结果 Evofosfamide在NPC细胞系中表现出缺氧选择性细胞毒性。在缺氧条件下,对CNE?2、HNE?1和HNE?1细胞的50%抑制浓度(50%inhibition concentration,IC50)分别为8.33±0.75、7.62±0.67和0.31±0.07μmol/L。与常氧对照组相比,在缺氧条件下其增敏率为9–300倍。通过联合指数值评估,evofosfamide联合DDP对NPC细胞的细胞毒性具有协同效应。在缺氧条件下用0.05μmol/L的evofosfamide处理后,细胞周期G2期被阻滞。在缺氧条件下用evofosfamide处理后,组蛋白H2AX磷酸化(Histone H2AXphosphorylation,γH2AX)(DNA损伤的标志之一)表达增强,而HIF?1α表达受到抑制。在HNE?1 NPC异种移植瘤模型中,evofosfamide作为单药或联合DDP显示出抗肿瘤活性。异种移植物组织缺氧区在evofosfamide单药治疗和联合DDP治疗后均明显减少。结论我们的结果为evofosfamide作为单药或联合DDP可选择性靶向鼻咽癌缺氧部分提供了临床前证据,为evofosfamide治疗鼻咽癌的潜在临床应用提供了理论依据。

Liposome-coated CaO_(2)nanoblockers for enhanced checkpoint blockade therapy by inhibiting PD-L1 de novo biosynthesis

The blocking of the immune checkpoint pathway with antibodies,especially targeting to programmed death-1/programmed death ligand-1(PD-1/PD-L1)pathway,was currently a widely used treatment strategy in clinical practice.However,the shortcomings of PD-L1 antibodies were constantly exposed with the deepening of its research and their therapeutic effect was limited by the translocation and redistribution of intracellular PD-L1.Herein,we proposed to improve immune checkpoint blockade therapy by using liposomes-coated CaO_(2)(CaO_(2)@Lipo)nanoparticles to inhibit the de novo biosynthesis of PD-L1.CaO_(2)@Lipo would produce oxygen and reduce hypoxia-inducible factor-1α(HIF-1α)level,which then downregulated the expression of PD-L1.Our in vitro and in vivo results have confirmed CaO_(2)@Lipo promoted the degradation of HIF-1αand then downregulated the expression of PD-L1 in cancer cells for avoiding immune escape.Furthermore,to mimicking the clinical protocol of anti-PD-L1 antibodies+chemo-drugs,CaO_(2)@Lipo was combined with doxorubicin(DOX)to investigate the tumor inhibition efficiency.We found CaO_(2)@Lipo enhanced DOX-induced immunogenic cell death(ICD)effect,which then promoted the infiltration of T cells,strengthened the blocking effect,thus provided an effective means to overcome the traditional immune checkpoint blockade treatment.

The impact of ^(60)Co γ-ray on cycles to Hep-2 human laryngeal cancer cell in the condition of hypoxia

Objective： The aim of the study was to investigate the impact of 60Co y-ray on apoptosis, cell cycles and the expression of protein hypoxia-inducible factor-1α （HIF-1α） to Hep-2 cell line in the conditions of normoxia and hypoxia. Methods： Hep-2 cell were divided into 2 groups： group A （normoxia） and group B （hypoxia）. All of the ceils were exposed to y-ray with dosage being 0, 1, 3, 5, 10, 20, and 40 Gy. Flow cytometry was used to measure the protein level of HIF-1α and to detect apoptosis and cell cycles. The protein level of HIF-1α was also determined by immunohistochemistry and Western blotting. Results： The protein level of HIF-1α in group B was significantly higher than that in group A. In group A, low doses （1-5 Gy） of y-ray had caused G0/G1 cell cycle arrest and high doses （10-40 Gy） had caused G2/M cell cycle arrest. In group B, without exposure of y-ray （0 Gy） had caused G0/G1 cell cycle arrest, all of the different dosage of y-ray could cause G2/M cell cycle arrest. The curve of apoptosis rate in group A was a parabola, the apoptotic rate was related to the dosage of y-ray in a dosage dependent manner. The peak was at the point of 5 Gy. The apoptosis rate in group A was significantly higher than that in group B. Conclusion： Different doses of y-ray could cause different cell cycles arrest then make different impact on apoptosis to Hep-2 ceil. The lower apoptosis rate in condition of hypoxia maybe has a relationship with G2/M cell cycle arrest. Up-regulated HIF-1α protein may be one of the reasons for G2/M cell cycle arrest.

Electroacupuncture at Zusanli(ST36) Accelerates Intracerebral Hemorrhage-Induced Angiogenesis in Rats

Objective： To investigate the effects of electro-acupuncture on intracerebral hemorrhage （ICH）- induced angiogenesis and hypoxia-inducible factor-1 a （HIF-1 a） expression in rats. Me.otis： Adult male Sprague- Dawley rats were randomly divided into 4 groups of 24 rats each. ICH was induced in 3 groups by stereotactic injection of collagenase type Ⅶ into the right globus pallidus; of these, one group was not further treated, the second group underwent Zusanli （ST36）-acupuncture, and the third group underwent non-acupoint acupuncture. ＇The fourth group underwent sham operations. Acupuncture was performed by stimulation with electrical needles at frequencies of 2-20 Hz for 30 min per day. Angiogenesis on days 3, 7 and 14 was assessed by double iimmunolabeling, and expression of HIF-1 α was evaluated by immunohistochemistry, quantitative real time reverse chain reaction and Westem blotting. Results： 5-Bromo-2-deoxyuddine （BrdU）labeled nuclei in cerebral endothelial cells （ECs） resided around the hematoma and the labeling peaked from 7 to 14 days （P〈0.01）. HIF-1 a positive microvessels with a dilated outline were detected in pedhematomal tissues after ICH, with the vessels extending into the clot from the surrounding area beginning on day 7. Following ICH, HIF-1 a protein levels increased （P〈0.05）, but HIF-1 a mRNA levels did not change. Electro-acupuncture at the Zusanli （ST36） acupoint increased BrdU-labeled nuclei in cerebral ECs （P〈0.05） and up-regulated the expression of HIF-1 a protein （P〈0.05）, but had little effect on the spatial distribution of HIF-1α or on HIF-1α mRNA levels. Conclusions： Electro-acupuncture treatment at the Zusanli （ST36） acupoint may accelerate ICH-induced angiogenesis by up-regulating HIF-1 a protein, and may enhance recovery following hemorrhagic cerebral injury.

Inhibition of vascular endothelial growth factor expression by Chinese medicine of Hedyotis diffusa Willd herbal compounds

The Hedyotis diffusa Willd herbal compounds(HDWHCs)are commonly used as Chinese medicine to treat cancer patients with established clinical therapeutic efficacy in China.However,the underlying mechanisms remain to be elucidated.In this study,we used freeze-dried powder of the water extracts of HDWHCs to investigate the potential mechanisms of HDWHCs in cancer treatment.HDWHCs treatment significantly inhibited vascular endothelial growth factor(VEGF)mRNA levels and VEGF transcriptional activation in cancer cells.HDWHCs also had a remarkable inhibitory effect on the expression of hypoxia-inducible factor 1alpha(HIF-1alpha).Forced expression of HIF-1αrestored VEGF transcriptional activation inhibited by HDWHCs,indicating that HDWHCs suppressed VEGF expression through decreasing HIF-1alpha expression.Moreover,HDWHCs inhibited cyclooxygenase-2(COX-2)expression,and overexpression of HIF-1alpha restored HDWHCs’inhibitory effect on COX-2 at transcriptional level.These findings may provide better understanding of HDWHCs’anti-cancer mechanism in cancer treatment.

Efficacy of the hypoxia-activated prodrug evofosfamide (TH-302) in nasopharyngeal carcinoma in vitro and in vivo

Background:Tumor hypoxia is considered an important factor in metastasis and disease relapse.Evofosfamide is a hypoxia-activated prodrug that selectively targets the hypoxic regions of solid tumors.As hypoxia-inducible factor-1α(HIF-1α)is overexpressed in nasopharyngeal carcinoma(NPC)tissues,we performed the present study to evaluate the efficacy profile of evofosfamide in NPC.Methods:We evaluated the efficacy of evofosfamide as a single agent or combined with cisplatin(DDP)in the NPC cell lines CNE-2,HONE-1 and HNE-1,and in nude mouse xenograft tumor models.Results:Evofosfamide exhibited hypoxia-selective cytotoxicity in NPC cell lines,with 50%inhibition concentration(IC50)values of 8.33±0.75,7.62±0.67,and 0.31±0.07μmol/L under hypoxia in CNE-2,HONE-1 and HNE-1 cells,respectively.The sensitization ranged from ninefold to greater than 300-fold under hypoxia compared with normoxia controls.The combination of evofosfamide with DDP had a synergistic effect on cytotoxicity in the NPC cell lines by combination index values assessment.Cell cycle G2 phase was arrested after treated with 0.05μmol/L evofosfamide under hypoxia.Histone H2AX phosphorylation(γH2AX)(a marker of DNA damage)expression increased while HIF-1αexpression suppressed after evofosfamide treatment under hypoxic conditions.In the HNE-1 NPC xenograft models,evofosfamide exhibited antitumor activity both as a single agent and combined with DDP.Hypoxic regions in xeno-graft tissue were reduced after both evofosfamide monotherapy and combined therapy with DDP.Conclusions:Our results present preclinical evidence for targeting the selective hypoxic portion of NPC by evofosfa-mide as a single agent and combined with DDP and provide rationale for the potential clinical application of evofosfa-mide for the treatment of nasopharyngeal carcinoma.