乏氧诱导因子-1与肿瘤乏氧的研究进展

乏氧是实体肿瘤发展过程中的普遍现象,它能诱导肿瘤细胞发生一系列基因表达的改变以适应环境.乏氧诱导因子-1(hypoxia inducible factor-1,HIF-1)是其调控核心.一方面,HIF-1通过与靶基因启动子序列中的HRE结合调控其表达,增加肿瘤新血管和红细胞生成、改变能量代谢途径等,以增加氧的利用率、减少氧的消耗,同时通过调控细胞周期调节蛋白、凋亡相关基因的表达改变细胞周期、抑制细胞凋亡;另一方面,HIF-1的表达受多种基因产物的调控,如VHL,PTEN等.HIF-1有多种生物学功能,如促进红细胞生成、肿瘤血管形成、促进肿瘤的转移和侵袭等.通过药物或基因治疗的方式抑制HIF-1的活性是治疗肿瘤的一种新途径.     

HIF-1α在肿瘤乏氧微环境中的作用及其靶向治疗的研究进展

乏氧现象广泛存在于实体肿瘤中。乏氧诱导因子-1α (hypoxia inducible factor 1α, HIF-1α) 通过参与多种靶基因的转录调控影响肿瘤细胞的能量代谢、增殖和凋亡, 使细胞及组织产生一系列反应以适应缺氧环境, 同时促进肿瘤血管形成, 也增加肿瘤自身的侵袭性及对放化疗的抵抗性。以HIF-1α为靶点的治疗将可能成为肿瘤治疗的重要手段。      

转录因子HIF-1在乏氧肿瘤中的作用

临床上已经有许多证据表明肿瘤乏氧细胞的存在不仅使肿瘤对放化疗的抗拒性增加,而且使肿瘤更具有侵袭性,容易发生远处转移.其原因主要是乏氧存在能使肿瘤细胞的一些基因和蛋白的合成或表达增加,而在这个过程中转录因子乏氧诱导因子-1(HIF-1)起着中枢纽带作用,故本文拟对HIF-1的结构、功能、调节和临床应用前景作一简要综述.     

乏氧诱导因子-1和肿瘤放射敏感性

研究表明肿瘤微环境乏氧能引起肿瘤放疗抗拒性的增加,而在此过程中乏氧诱导因子-1 （HIF-1）起着关键的作用。这为研究和应用针对HIF-1的分子靶向治疗以提高肿瘤放射敏感性提供了一条有效的途径。     

宫颈癌患者外周血淋巴细胞的表达及其与乏氧诱导因子-1α的关系

摘 要：［目的］ 评价外周血淋巴细胞与宫颈癌临床病理特征及乏氧诱导因子-1α(HIF-1α)的关系。［方法］ 采用流式细胞法检测68例宫颈鳞癌患者外周血淋巴细胞和免疫组化法检测相应的组织标本中HIF-1α蛋白表达。［结果］ 与FIGO Ⅰ/Ⅱ期和无淋巴结转移相比,宫颈癌患者外周血中CD4+ T、CD4+CD25+/high CD127 low/neg、CD4+CD25+FoxP3+细胞在FIGO Ⅲ期、淋巴结转移患者明显升高。HIF-1α在宫颈癌组织中的阳性和阴性表达率分别为58.8%和41.2%,其中CD4+CD25+/highCD127low/neg和CD4+CD25+ FoxP3+细胞与HIF-1α呈正相关。68例患者中位随访时间60个月,5年总生存率为52.9%,其中HIF-1α(+)和HIF-1α(-)患者5年生存率分别为42.5%和67.9% (χ2=4.145,P=0.042)。Cox回归分析提示HIF-1α是宫颈癌的危险因素。［结论］宫颈癌淋巴细胞的变化与HIF-1α有关。宫颈癌患者外周血淋巴细胞分布异常,均参与宫颈癌的浸润和转移,有望作为宫颈癌病情评估的参与指标。     

乏氧诱导因子-1α在非小细胞肺癌中的表达研究

目的　探讨乏氧诱导因子 1α(HIF 1α)在非小细胞肺癌中的表达水平及其临床意义。方法　采用免疫组织化学技术检测HIF 1α在 68例非小细胞肺癌标本中的表达。结果　HIF 1α在非小细胞肺癌中的阳性表达率为 5 7.3 5 %( 3 9/ 68)。腺癌中HIF 1α阳性表达率为 5 4.76%( 2 3 / 42 ) ,鳞癌为 61.5 4%( 16/ 2 6) (P>0 .0 5 ) ;中高分化的肿瘤标本中HIF 1α阳性表达率 ( 74.2 9%,2 6/ 3 5 )显著高于低分化的肿瘤标本 3 9.3 9%( 13 / 3 3 ) (P <0 .0 5 ) ;Ⅰ～Ⅱ期HIF 1α的阳性表达率 ( 86.96%,2 0 / 2 3 )显著高于Ⅲ～Ⅳ期 42 .2 2 %( 19/ 45 ) (P<0 .0 5 )。HIF 1α的表达与患者性别、年龄及有无淋巴结转移无明显关系。结论　HIF 1α在非小细胞肺癌中有着较高的表达率 ,且与肿瘤的分化程度和临床分期有一定的关系 ,提示在非小细胞肺癌的治疗中应该重视HIF 1α导致的放化疗抗拒     

食管癌99mTc-HL91乏氧显像和HIF-1α表达水平的相关性研究

目的:研究食管癌99mTc-HL91乏氧显像以及与乏氧诱导因子-1α(HIF-1α)表达水平的相关性。方法:50例食管癌患者行SPECT99mTc-HL91乏氧显像,利用感兴趣区技术分别勾画各时相肿瘤(T)和相应正常食管部位(N)放射性计数比值,即T/N值,免疫组化方法检测肿瘤组织HIF-1α表达水平。结果:50例病灶对99mTc-HL91的摄取均高于相应正常组织,99mTc-HL91摄取程度与肿瘤病理分级无相关关系(P>0.05);注射99mTc-HL91 4小时后SPECT显像颈段和胸上段食管癌T/N值为2.04±0.38,胸中段食管癌T/N值为2.16±0.32,胸下段食管癌T/N值为2.18±0.41,三者无显著性差异(P>0.05);病灶的T/N值为1.36-4.43(中位值2.45),免疫组化结果显示表达HIF-1α的细胞数为23.1%-76.9%(中位数52.9%),两者之间呈正相关(P<0.05)。结论:食管癌组织对乏氧显像剂99mTc-HL91有显著摄取,摄取值与肿瘤病理分级及病变部位无相关性,但与HIF-1α的表达正相关。     

食管癌^99mTc—HL91乏氧显像和HIF—1α表达水平的相关性研究

目的：研究食管癌^99mTc～HL91乏氧显像以及与乏氧诱导因子-1α（HIF—1α）表达水平的相关性。方法：50例食管癌患者行SPECT^99mTc—HL91乏氧显像,利用感兴趣区技术分别勾画各时相肿瘤（T）和相应正常食管部位（N）放射性计数比值,即T／N值,免疫组化方法检测肿瘤组织HIF-1α表达水平。结果：50例病灶对^99mTc—HL91的摄取均高于相应正常组织,^99mTc—HL91摄取程度与肿瘤病理分级无相关关系（P〉0．05）;注射^99mTc—HL914小时后SPECT显像颈段和胸上段食管癌T／N值为2．04±0．38,胸中段食管癌T／N值为2．16±0．32,胸下段食管癌T／N值为2．18±0．41,三者无显著性差异（P〉0．05）;病灶的T／N值为1．36—4．43（中位值2．45）,免疫组化结果显示表达HIF—1α的细胞数为23．1％-76．9％（中位数52．9％）,两者之间呈正相关（P〈0．05）。结论：食管癌组织对乏氧显像剂^99mTc—HL91有显著摄取,摄取值与肿瘤病理分级及病变部位无相关性,但与HIF-1α的表达正相关。     

乏氧对基质金属蛋白酶促肿瘤转移的影响研究进展

乏氧是实体瘤中普遍存在的现象，并且能引起肿瘤细胞一系列生物学行为的改变，如促进肿瘤转移，在此过程中乏氧诱导因子-1（hypoxia inducible factor-1，HIF-1）起着核心的作用。细胞外基质（extracellular matrix．ECM）的降解是肿瘤细胞转移的前提，而基质金属蛋白酶（matrix metalloproteinases，MMPs）能降解ECM，在肿瘤转移这一关键步骤中起着重要作用。而乏氧是否会影响MMPs来促进肿瘤转移，其作用机制尚不清楚，本文对HIF-1和MMPs在肿瘤转移中作用及相互影响进行综述。     

乏氧诱导因子-1α在非小细胞肺癌中的表达研究(英文)

目的探讨乏氧诱导因子-1α(HIF-1α)在非小细胞肺癌中的表达水平及其临床意义。方法采用免疫组织化学技术检测乏氧诱导因子-1α在68例非小细胞肺癌标本中的表达。结果 (1)HIF-1α在非小细胞肺癌中的总的阳性表达率为57.35%(39/68);(2)腺癌中HIF-1α的阳性表达率为54.76%(23/42), 鳞癌中 HIF-1α的阳性表达率61.54%(16/26),腺癌与鳞癌之间 HIF-1α的阳性表达率无显著差异(P>0.05);中高分化的肿瘤标本中 HIF-1α的阳性表达率为74.28%(26/35)高于低分化的肿瘤标本中 HIF-1α的阳性表达率39.39%(13/33)(P<0.05);(3)HIF-1α的表达与性别、年龄及有无淋巴结转移和临床分期无关。结论 HIF-1α在非小细胞肺癌中有着较高的表达率,且与肿瘤的分化程度有一定的关系。     

Upregulation of CYP1B1 by hypoxia is mediated by ERα activation in breast cancer cells

Endocrine therapy for breast cancer often leads to drug resistance and tumor recurrence; tumor hypoxia is also associated with mortality and tumor relapse. Cytochrome P450 1B1 (CYP1B1) regulates estrogen metabolism in breast cells and is known to be overexpressed in breast cancer tissue. Although the individual association of hypoxia-induced hypoxia-inducible factor-1-alpha (HIF-1α) and CYP1B1 with tumorigenesis is well known, the association between HIF-1α and CYP1B1 leading to tumorigenesis has not been investigated. Here, we investigated the correlation between hypoxia and CYP1B1 expression in breast cancer cells for tumorigenesis-related mechanisms. Hypoxia was induced in the human breast cancer cell lines MCF-7 (Er-positive) and MDA-MB-231 (triple-negative) and the normal breast epithelial cell line MCF10A; these cell lines were then subjected to immunoblotting, transient transfection, luciferase assays, gene silencing using small interfering RNA, polymerase chain reaction analysis, chromatin immunoprecipitation, co-immunoprecipitation, and mammalian two-hybrid assays. Furthermore, immunofluorescence analysis of the tumor microarrays was performed, and the pub2015 and the Cancer Genome Atlas patient datasets were analyzed. HIF-1α expression in response to hypoxia occurred in both normal and breast cancer cells, whereas CYP1B1 was induced only in estrogen receptor α (ERα)-positive breast cancer cells under hypoxia. HIF-1α activated ERα through direct binding and in a ligand-independent manner to promote CYP1B1 expression. Therefore, we suggested the mechanism by which hypoxia and ER-positivity orchestrate breast cancer relapse.     

低氧对再生医学中间充质干细胞培养的研究进展

由于间充质干细胞（MSCs）具有自我更新、免疫抑制能力和多系分化潜能等特征,因此被认为是干细胞再生治疗中一个重要资源。然而,体外扩增期间的低生产动力学、早期衰老、基因不稳定性和低移植率是MSCs在再生治疗中的主要不利因素。细胞间及细胞内大量的信号通路在其壁龛中控制着MSCs的生长、倍增和分化。通常,干细胞培养的实验条件为20％的环境O2浓度,而壁龛中通常为2％～9％O2。O2通过调节乏氧诱导因子－1（HIF－1）来介导不同基因的表达,从而对维持干细胞增殖和分化具有重要作用。本文主要描述和对比常氧（20％O2）和低氧（2％～9％O2）对MSCs的生物学影响。并总结了在体外培养扩增中,低氧环境显著提高MSCs的生长动力学、遗传稳定性和趋化因子受体的表达,最终提高MSCs在再生治疗中的效应。     

三阴乳腺癌的研究进展(英文)

Triple-negative breast cancer (TNBC) is a unique subgroup defined by a lack expression of ER (estrogen receptor), PR(progesterone receptor) and HER2 (human epidermal growth factor receptor 2), which has distinctly biological, clinical and pathological characteristics. This subgroup has close relationship with basal-like and BRCA1 (breast cancer susceptibility gene-1) breast cancers. Since endocrine and HER2-targered therapy can not be applied, chemotherapy is the major mean of therapy. Some studies show tha...     

TGFBI modulates tumour hypoxia and promotes breast cancer metastasis

Breast cancer metastasis is a complex process that depends not only on intrinsic characteristics of metastatic stem cells, but also on the particular microenvironment that supports their growth and modulates the plasticity of the system. In search for microenvironmental factors supporting cancer stem cell (CSC) growth and tumour progression to metastasis, we here investigated the role of the matricellular protein transforming growth factor beta induced (TGFBI) in breast cancer. We crossed the MMTV‐PyMT model of mammary gland tumorigenesis with a Tgfbi ^Δ/Δ mouse and studied the CSC content of the tumours. We performed RNAseq on wt and ko tumours, and analysed the tumour vasculature and the immune compartment by IHC and FACS. The source of TGFBI expression was determined by qPCR and by bone marrow transplantation experiments. Finally, we performed in silico analyses using the METABRIC cohort to assess the potential prognostic value of TGFBI. We observed that deletion of Tgfbi led to a dramatic decrease in CSC content and lung metastasis. Our results show that lack of TGFBI resulted in tumour vessel normalisation, with improved vessel perfusion and decreased hypoxia, a major factor controlling CSCs and metastasis. Furthermore, human data mining in a cohort of breast cancer patients showed that higher expression of TGFBI correlates with poor prognosis and is associated with the more aggressive subtypes of breast cancer. Overall, these data reveal a novel biological mechanism controlling metastasis that could potentially be exploited to improve the efficacy and delivery of chemotherapeutic agents in breast cancer.

Abbreviations

CSC

cancer stem cell

ECM

extracellular matrix

EMT

epithelial‐to‐mesenchymal transition

FACS

fluorescence‐activated cell sorting

TGFBI

transforming growth factor beta induced

     

ALDH1A1增强乳腺癌细胞血管生成因子表达并促进共培养HUVEC细胞小管形成和侵袭能力

目的:探讨干细胞标志物醛脱氢酶1A1（ALDH1A1）对乳腺癌细胞血管生成因子表达的影响,以及对与乳腺癌细胞共培养的HUVEC细胞小管形成和侵袭能力的影响。方法:采用免疫组化检测了乳腺癌组织和乳腺增生组织中ALDH1A1的表达。使用ALDH1A1 shRNA或过表达ALDH1A1的pcDNA3.1质粒转染乳腺癌细胞（MCF-7和MDA-MB-231）,通过qRT-PCR和Western blot检测敲低或过表达ALDH1A1对乳腺癌细胞中血管内皮生长因子（VEGF）、缺氧诱导因子-1α（HIF-1α）和白细胞介素-12（IL-12）表达的影响。通过用1 μmol/L 的外源性RA和RAR阻断剂（AGN 193109）处理乳腺癌细胞48 h来考察视黄酸信号通路是否参与ALDH1A1对VEGF和HIF-1α的调控过程。将乳腺癌细胞（MCF-7和MDA-MB-231）和HUVEC细胞共培养来模拟肿瘤形成的微环境,并检测HUVEC的小管形成能力和细胞侵袭能力。结果:乳腺癌组织的ALDH1A1染色平均光密度显著高于乳腺增生组织,并且淋巴结转移的乳腺癌组织显著高于未淋巴结转移的乳腺癌组织（P＜0.05）。敲低ALDH1A1可显著降低MCF-7和MDA-MB-231细胞中VEGF和HIF-1α蛋白表达,并上调IL-12蛋白表达。然而,上调ALDH1A1表达则可逆转上述变化。外源性RA处理可显著上调MCF-7和MDA-MB-231细胞中VEGF和HIF-1α的表达,然而,RAR阻断剂处理可抑制MCF-7和MDA-MB-231细胞中VEGF和HIF-1α的上调。敲低乳腺癌细胞中ALDH1A1的表达可导致共培养的HUVEC细胞的小管形成能力和侵袭能力显著降低。而上调乳腺癌细胞中ALDH1A1的表达则可显著促进共培养的HUVEC细胞的小管形成能力和侵袭能力。结论:在乳腺癌细胞中,ALDH1A1通过激活HIF-1α和视黄酸信号通路来上调血管生成因子的表达并提高共培养的内皮细胞的血管生成能力,从而增加肿瘤的侵袭性。     

乳腺癌微转移的研究进展

微转移是乳腺癌早期即发生的行为，与预后密切相关。近年来，随着影像学、病理学、免疫组化技术及分子生物学技术的发展，乳腺癌微转移的诊断水平有了长足的进步。本文综述了乳腺癌微转移方面的最新进展。     

缺氧对人乳腺癌细胞系MCF-7生物学行为的影响

目的:研究缺氧对人乳腺癌细胞系MCF-7的生物学行为,增殖、侵袭能力的影响。通过影响缺氧诱导因子1α(hypoxic-induciblefactor1α,HIF-1α)的表达,检验其在这一过程中的作用,并进一步探讨作用机制。方法:慢病毒感染细胞,干扰乳腺癌细胞系MCF-7中HIF-1α的表达,得到HIF-1α表达正常的乳腺癌细胞系MCF-7-NC和HIF-1α表达受干扰的细胞系MCF-7-HIF△。分别低氧培养及化学药物诱导缺氧,用MTT法检测2组细胞系在缺氧和正常培养条件下的增殖能力,ANOVA检验检测其增殖能力的区别。Transwell实验检验缺氧和正常培养条件下人乳腺癌细胞的侵袭能力,计数通过Transwell小室的细胞,ANOVA检验检测细胞侵袭能力的区别。共聚焦免疫荧光法检测缺氧后2组乳腺癌细胞的上皮和间质标记物的表达,检验细胞系是否发生了上皮-间质转化(epithelial-mesenchymaltransition,EMT)。结果:MTT实验结果:正常表达HIF-1α的MCF-7-NC的增殖能力在缺氧后与正常培养条件下相比明显减弱,其差别具有统计学意义(P<0.05)。HIF-1α表达受干扰的MCF-7-HIF△的增殖能力在缺氧和正常培养条件下相比无显著区别。Transwell实验检测细胞的侵袭能力,缺氧后正常表达HIF-1α的MCF-7-NC的侵袭能力较正常培养的细胞明显增强,其差别具有统计学意义(P<0.05)。HIF-1α表达受干扰的MCF-7-HIF△侵袭能力在缺氧和正常培养下无显著区别。缺氧后,正常表达HIF-1α的细胞系MCF-7-NC发生上皮-间质转化(epithelial-mesenchymaltransition,EMT)。共聚焦荧光染色显示:在诱导缺氧后,正常表达HIF-1α的MCF-7-NC细胞极性发生变化,呈长梭形改变,上皮标志物人广谱角蛋白(pan-cytokeratin,P-CK)表达下调,间质标志物人α平滑肌动蛋白(α-SMA)表达上调;而HIF-1α表达受干扰的MCF-7-HIF△无明显EMT变化。结论:在体外条件下,缺氧可以引起乳腺癌细胞系MCF-7增殖能力减弱、侵袭能力增强,可以诱导乳腺癌细胞MCF-7发生EMT,干扰缺氧诱导因子亚基HIF-1α的表达,则缺氧对乳腺癌细胞增殖、侵袭的影响消失。     

胰岛素样生长因子-1在乳腺癌组织中的表达

Objective  We investigated the expression of insulin-like growth factor-1 (IGF-1) so as to explore its relationship with carcinogenesis and development of breast cancer. Methods  IGF-1 mRNA levels in tissues of breast cancer, adjacent breast cancer in 70 cases breast cancer patients were analyzed by RT-PCR with the normal breast tissues of paired breast as the control. Results  The level of IGF-1 mRNA expression in breast cancer tissues was significantly higher than that in the paired adjacent to breast cancer tissues, normal mammary gland tissues. The ration of IGF-1/β-actin were 0.679 ± 0.075, 0.463 ± 0.085, 0.305 ± 0.031, respectively. There was significant difference between different groups (P < 0.005). Expression of IGF-1 was associated with lymph node metastasis, pathological staging and estrogen receptor status of breast cancer and no significant relationship with tumor pathological grouping (P > 0.005). Conclusion  The high-level expression of IGF-1 in breast cancer tissues is correlated with carcinogenesis, development and metastasis of breast cancer.     

乳腺癌相关MicroRNAs研究进展

MicroRNAs(miRNAs)是一类广泛存在于真核细胞中长约18~23个核苷酸的小分子非编码RNA,具有转录后基因调控的功能,参与调节细胞的分化、增殖、凋亡、迁移等多种生物学进程.现今乳腺癌已成为女性常见的恶性肿瘤之一,但其发病病因尚未完全清楚.近年来,通过对分子生物学的研究,发现miRNAs是一类潜在的强有力的评估乳腺癌的发生、发展,诊断、治疗及预后的生物学指标.本文主要对miRNAs这一类新的肿瘤分子生物学标记物在乳腺癌中的作用机制作一综述.     

Mitochondrial malic enzyme 2 promotes breast cancer metastasis via stabilizing HIF-1α under hypoxia

Objectiveα-ketoglutarate (α-KG) is the substrate to hydroxylate collagen and hypoxia-inducible factor-1α (HIF-1α), which are important for cancer metastasis. Previous studies have shown that the upregulation of collagen prolyl 4-hydroxylase in breast cancer cells stabilizes the expression of HIF-1α by depleting α-KG levels. We hypothesized that mitochondrial malic enzyme 2 (ME2) might also affect HIF-1α expression via modulating α-KG levels in breast cancer cells.MethodsWe evaluated ME2 protein expression in 100 breast cancer patients using immunohistochemistry and correlated with clinicopathological indicators. The effect of ME2 knockout on cancer metastasis was evaluated using an orthotopic breast cancer model. The effect of ME2 knockout or knockdown on the levels of α-KG and HIF-1α proteins in breast cancer cell lines was determined both in vitro and in vivo. ResultsME2 was found to be upregulated in the human breast cancerous tissues compared with the matched precancerous tissues (P<0.001). The elevated expression of ME2 was associated with a poor prognosis (P=0.019). ME2 upregulation was also related to lymph node metastasis (P=0.016), pathological staging (P=0.033), and vascular cancer embolus (P=0.014). Also, ME2 knockout significantly inhibited lung metastasisin vivo. In the tumors formed by ME2 knockout cells, the levels of α-KG were significantly increased and collagen hydroxylation level did not change significantly but HIF-1α protein expression was significantly decreased, compared to the control samples. In cell culture, cells with ME2 knockout or knockdown demonstrated significantly higher α-KG levels but significantly lower HIF-1α protein expression than control cells under hypoxia. Exogenous malate and α-KG exerted similar effect on HIF-1α in breast cancer cells to ME2 knockout or knockdown. Additionally, treatment with malate significantly decreased 4T1 breast cancer lung metastasis. ME2 expression was associated with HIF-1α levels in human breast cancer samples (P=0.008). ConclusionsOur results provide evidence that upregulation of ME2 is associated with a poor prognosis of breast cancer patients and propose a mechanistic understanding of a link between ME2 and breast cancer metastasis.