Vectorlike quarks(VLQs)with masses at the TeV-scale have been predicted in many new physics scenarios beyond the Standard Model(SM).Based on a simplified(X,T)doublet model including the exotic vectorlike X quark(VLQ-X...Vectorlike quarks(VLQs)with masses at the TeV-scale have been predicted in many new physics scenarios beyond the Standard Model(SM).Based on a simplified(X,T)doublet model including the exotic vectorlike X quark(VLQ-X)with an electric charge 5/3,we study the production of the VLQ-X decaying into tW at the future Compact Linear Collider(CLIC)with √s=3 TeV including the initial state radiation and beamstrahlung effects.We focus on the final signals,including same-sign dileptons(electrons or muons),at least one b-tagged jet,and large missing transverse momentum.By performing detailed signal-to-background analyses and detector simulations,we obtain the 2σexclusion capabilities and discovery reaches,respectively,on the mass of the VLQ-Xmx as well as the relevant parameters(Br(X→_(t)W))for mx≥1500GeV and the coupling strength g^(*) for mx≥1500 GeV)for some typical luminosities at the 3 TeV CLIC.展开更多
One of the main problems in particle physics is to understand the origin and nature of dark matter. An exciting possibility is to consider that dark matter belongs to a new complex but hidden sector. In this paper, we...One of the main problems in particle physics is to understand the origin and nature of dark matter. An exciting possibility is to consider that dark matter belongs to a new complex but hidden sector. In this paper, we assume the existence of a strongly interacting dark sector consisting of a new scalar doublet and new vector resonances,in accordance with the model recently proposed by our group. Since it was found in the previous work that it is very challenging to find the new vector resonances at the LHC, here we study the possibility of finding them at the future Compact Linear Collider(CLIC) running at■= 3 TeV. We consider two distinct scenarios. In the first, when the non-standard scalars are heavy, the dark resonance is intense enough to make its discovery possible at CLIC when the resonance mass is in the range [2000, 3000] GeV. In the second scenario, when the non-standard scalars are light, the new vector boson is too broad to be recognized as a resonance, and is not detectable except when the mass of the scalars is close to(but smaller than) half of the resonance mass and the scale of the dark sector is high. In all positive cases, less than a tenth of the maximum integrated luminosity is needed to reach the discovery level. Finally, we also comment on the mono-Z production.展开更多
The Compact Linear Collider （CLIC） is a future e＋e linear collider. The CLIC study concentrated on a design of center-of-mass energy of 3 TeV and demonstrated the feasibility of the technology. However, the physics...The Compact Linear Collider （CLIC） is a future e＋e linear collider. The CLIC study concentrated on a design of center-of-mass energy of 3 TeV and demonstrated the feasibility of the technology. However, the physics also demands lower energy collision. To satisfy this, CLIC can be built in stages. The actual stages will depend on LHC results. Some specific scenarios of staged constructions have been shown in CLIC Concept Design Report （CDR）. In this paper, we concentrate on the main linac lattice design for Ecm=l TeV CLIC aiming to upgrade from E~.,=500 GeV CLIC and then to Ecru=3 TeV one. This main linac accelerates the electron or positron beam froth 9 GeV to 500 GeV. A primary lattice design based on the 3 TeV CLIC main linac design and its optimization based on the beam dynamics study will be presented. As we use the same design principles as 3TeV CLIC main linac, this optimization is basically identical to the 3 TeV one. All the simulations results are obtained using the tracking code PLACET.展开更多
The ability to visualise proteins in their native environment and discern information regarding stoichiometry is of critical importance when studying protein interactions and function. We have used liquid cell atomic ...The ability to visualise proteins in their native environment and discern information regarding stoichiometry is of critical importance when studying protein interactions and function. We have used liquid cell atomic force microscopy (AFM) to visualise proteins in their native state in buffer and have determined their molecular volumes. The human proteins S100A8, S100A9, S100A12 and CLIC1 were used in this investigation. The effect of oxidation on the protein structure of CLIC1 was also investigated and we found that CLIC1 multimerisation could be discerned by AFM, which supports similar findings by other methods. We have found good correlation between the molecular volumes measured by AFM and the calculated volumes of the individual proteins. This method allows for the study of single soluble proteins under physiological conditions and could potentially be extended to study the structure of these proteins when located within a membrane environment.展开更多
In a simplified model including an SU(2)singlet vector-like top quark T(VLT)with charge 2/3,we investigate the associated production of Wb with VLT at a Compact Linear Collider(CLIC).Focusing on the T→Wb decay channe...In a simplified model including an SU(2)singlet vector-like top quark T(VLT)with charge 2/3,we investigate the associated production of Wb with VLT at a Compact Linear Collider(CLIC).Focusing on the T→Wb decay channel,we discuss two decay models:e+e-→TW+b→(l-vb)(jjb)and e+e-→TW+b→(jjb)(l+νb).In this paper,we consider recent experimental limits including the electroweak precision observables,the width of the top quark,and the direct LHC searches.Through a detailed detector simulation,we show the exclusion and discovery capability on the T at 3 TeV CLIC,where the initial state radiation effect has also been considered.The results show that it is promising to detect the VLT at future high-energy e+e-colliders.展开更多
From July 31st to August 1st,2018,the International Workshop on Cryospheric Changes and Their Regional and Global Impacts,co-sponsored by the State Key Laboratory of Cryospheric Science of Northwest Institute of Eco-E...From July 31st to August 1st,2018,the International Workshop on Cryospheric Changes and Their Regional and Global Impacts,co-sponsored by the State Key Laboratory of Cryospheric Science of Northwest Institute of Eco-Environment and Resources(NIEER),Chinese Academy of Sciences,People's Government of Dunhuang City,the International Association of Cryospheric Sciences(IACS),the World Climate Research Program Climate and Cryosphere(WCRP)/the Climate and Cryosphere(CliC),the University of Alaska Fairbanks and others,was successfully held in Dunhuang,Gansu Province.展开更多
Our research focused on the analy sis of concrete deterioration mechan ism under the coup ling effects of flexural load,cy clic wetting and dry ing, and sulfate. The relative dy namic modulus of elasticity of a corrod...Our research focused on the analy sis of concrete deterioration mechan ism under the coup ling effects of flexural load,cy clic wetting and dry ing, and sulfate. The relative dy namic modulus of elasticity of a corroded concrete samp le was tested, and scannin g electron microscop e was used to observe the microstructure of concrete under the coup ling effects of flexural load,cy clic wetting and dry ing, and sulf ate. Results manif ested that flexur al load and cy clic wetting and dry ing durin g the concrete service chan ged the corrosion p rocess of the sulfate mediu m in con crete and enh anced the deterioration of con crete p erforman ce.Furthermore, the influencin g p atterns of strength grade of concr ete, mass concentration of sulfate solution, and mineral admixtures on the degree of concrete deterioration were identified.展开更多
In this study,light-by-light(LBL)scattering with initial polarized Compton backscattered photons at the CLIC,induced by axion-like particles(ALPs),is investigated.The total cross sections are calculated assuming CP-ev...In this study,light-by-light(LBL)scattering with initial polarized Compton backscattered photons at the CLIC,induced by axion-like particles(ALPs),is investigated.The total cross sections are calculated assuming CP-even coupling of the pseudoscalar ALP to photons.The 95%C.L.exclusion region for the ALP mass ma and its coupling constant f is presented.The results are compared with CLIC bounds previously obtained for the unpolar-ized case.It is shown that the bounds onf for the polarized beams in the region m_(a)=1000-2000 GeV with colli-sion energy of 3000 GeV and integrated luminosity of 4000 fb^(-1)are on average 1.5 times stronger than the bounds for the unpolarized beams.Moreover,our CLIC bounds are stronger than those for all current exclusion regions for m_(a)>80 GeV.In particular,they are more restrictive than the limits that follow from the ALP-mediated LBL scatter-ing at the LHC.展开更多
[目的]研究绞股蓝总皂苷(gypenosides,GPs)对RAW264.7细胞脂质累积及细胞内氯离子通道蛋白1(chloride intracellular channel 1,CLIC1)表达的影响,探讨GPs抗动脉粥样硬化的分子机制。[方法]将RAW264.7细胞接种于六孔板中,分为NC组、氧...[目的]研究绞股蓝总皂苷(gypenosides,GPs)对RAW264.7细胞脂质累积及细胞内氯离子通道蛋白1(chloride intracellular channel 1,CLIC1)表达的影响,探讨GPs抗动脉粥样硬化的分子机制。[方法]将RAW264.7细胞接种于六孔板中,分为NC组、氧化型低密度脂蛋白(oxidized low density lipoprotein,ox-LDL)组、GPs 10组、GPs 50组、GPs 100组及CLIC1 si RNA组。各组细胞处理24h后,油红O染色检测各组细胞内脂质的累积,化学法检测细胞内总胆固醇(total cholesterol,TC)及游离胆固醇(free cholesterol,FC)的含量,荧光定量PCR和免疫印迹法检测CLIC1、CD36m RNA和蛋白质的表达,免疫荧光技术观察CLIC1的细胞定位,并用MQAE法检测细胞内氯离子浓度的变化。[结果]与NC组相比,ox-LDL组CLIC1、CD36 m RNA(P<0.01,P<0.001)及蛋白(P<0.01,P<0.001)表达水平显著升高,细胞内TC(P<0.001)、FC(P<0.01)显著升高,细胞膜上CLIC1表达显著升高,细胞内氯离子浓度显著增加(P<0.01);经CLIC1 si RNA或GPs处理后,细胞内TC(P<0.001,P<0.001)、FC(P<0.01,P<0.01)含量降低,脂质累积减少,CLIC1、CD36 m RNA及蛋白表达水平显著下调(P<0.01,P<0.001)。[结论]CLIC1在巨噬细胞脂质累积中发挥着重要的作用,GPs可以通过调控CLIC1的表达抑制巨噬细胞脂质累积。展开更多
Systematic studies on the cryosphere in China started in the late 1950s. Significant achievements have been made by continuous investigation of glacier inventories, frozen ground observations, paleo-climate analyses o...Systematic studies on the cryosphere in China started in the late 1950s. Significant achievements have been made by continuous investigation of glacier inventories, frozen ground observations, paleo-climate analyses of ice cores, process studies and the modeling of cryopsheric/atmospheric interactions. The general facts and understanding of these changes include： （1） Solid precipitation, including the number of days with frost and hail storms, shows a decreasing tendency over the past half century. （2） In most areas glaciers are retreating or have completely vanished （〉80%）, some glaciers are still advancing （5%-20% depending upon time period）. The annual glacial melt water has been increasing since the 1980s. This increased supply of melt water to river runoff in Northwest China is about a 10%-13%. （3） The long-term variability of snow cover in western China is characterized by a large inter-annual variation superimposed on a small increasing trend. Snow cover variability in the Qinghai-Xizang Plateau （QXP） is influenced by the Indian monsoon, and conversely impacts monsoon onset and strength and eventually the drought and flood events in middle-low reaches of Yangtze River. （4） Frozen ground, including permafrost, is decaying both in QXP and in Northeast China. The most significant changes occurred in the regions with thickest seasonal frozen ground （SFG）, i.e., inland QXP, then northeastern and northwestern QXP. The cold season air temperature is the main factor controlling SFG change. The increase of ground surface temperatures is more significant than air temperature. （5） The sea ice coverage over the Bohai Sea and Yellow Sea has deceased since the 1980s. （6） River ice duration and ice thickness is also decreasing in northern China. In 2001, the Chinese National Committee of World Climate Research Program/Climate and Cyosphere （WCRP/CliC） （CNC-CliC） was organized to strengthen research on climate and cryosphere in China. Future monitoring of the cryosphere展开更多
AIM: To develop novel biomarkers of rectal radiotherapy, we measured gene expression profiles on biopsies taken before and during preoperative radiotherapy. METHODS: Six patients presenting with a locally advanced rec...AIM: To develop novel biomarkers of rectal radiotherapy, we measured gene expression profiles on biopsies taken before and during preoperative radiotherapy. METHODS: Six patients presenting with a locally advanced rectal cancer (T>T2, N0/Nx, M0) eligible for preoperative radiotherapy (45 Gy in 25 fractions) were selected in a pilot study. Six tumor and 3 normal tissues biopsies were taken before and during radiotherapy,after a dose of 7.2 Gy at a median time of 1 h following irradiation (0:27-2:12). Tumor or normal tissue purity was assessed by a pathologist prior to RNA extraction. Mean RNA content was 23 μg/biopsy (14-37) before radiotherapy and 22.7 μg/biopsy (12-35) during radiotherapy. After RNA amplification, biopsies were analysed with 54K HG-U133A Plus 2.0 Affymetrix expression micro-arrays. Data were normalized according to MAS5 algorithm. A gene expression ratio was calculated as: (gene expression during radiotherapy-gene expression before radiotherapy)/gene expression before radiotherapy. Were selected genes that showed a ratio higher than ± 0.5 in all 6 patients. RESULTS: Microarray analysis showed that preoperative radiotherapy significantly up-regulated 31 genes and down-regulated 6 genes. According to the Gene Ontology project classification, these genes are involved in protein metabolism (ADAMDEC1 ; AKAP7 ; CAPN5 ; CLIC5 ; CPE ; CREB3L1 ; NEDD4L ; RAB27A), ion transport (AKAP7 ; ATP2A3 ; CCL28 ; CLIC5 ; F2RL2 ; NEDD4L ; SLC6A8), transcription (AKAP7 ; CREB3L1 ; ISX ; PAB-PC1L ; TXNIP), signal transduction (CAPN5 ; F2RL2 ; RA- B27A ; TNFRSF11A), cell adhesion (ADAMDEC1 ; PXDN ; SPON1 ; S100A2), immune response (CCL28 ; PXDN ; TNFRSF11A) and apoptosis (ITM2C ; PDCD4 ; PVT1). Up-regulation of 3 genes (CCL28 ; CLIC5 ; PDCD4) was detected by 2 different probes and up-regulation of 2 genes (RAB27A ; TXNIP) by 3 probes. CONCLUSION: Micro-arrays can efficiently assess early transcriptomic changes during preoperative radiotherapy for rectal cancer, and may help better understand tumor radioresistance.展开更多
基金Supported by the Science and Technology Plan Projects of Henan Province,China(222102310483)。
文摘Vectorlike quarks(VLQs)with masses at the TeV-scale have been predicted in many new physics scenarios beyond the Standard Model(SM).Based on a simplified(X,T)doublet model including the exotic vectorlike X quark(VLQ-X)with an electric charge 5/3,we study the production of the VLQ-X decaying into tW at the future Compact Linear Collider(CLIC)with √s=3 TeV including the initial state radiation and beamstrahlung effects.We focus on the final signals,including same-sign dileptons(electrons or muons),at least one b-tagged jet,and large missing transverse momentum.By performing detailed signal-to-background analyses and detector simulations,we obtain the 2σexclusion capabilities and discovery reaches,respectively,on the mass of the VLQ-Xmx as well as the relevant parameters(Br(X→_(t)W))for mx≥1500GeV and the coupling strength g^(*) for mx≥1500 GeV)for some typical luminosities at the 3 TeV CLIC.
基金Supported by Conicyt(Chile)(PIA/ACT-1406,PIA/Basal FB0821)Fondecyt(Chile)(1160423)
文摘One of the main problems in particle physics is to understand the origin and nature of dark matter. An exciting possibility is to consider that dark matter belongs to a new complex but hidden sector. In this paper, we assume the existence of a strongly interacting dark sector consisting of a new scalar doublet and new vector resonances,in accordance with the model recently proposed by our group. Since it was found in the previous work that it is very challenging to find the new vector resonances at the LHC, here we study the possibility of finding them at the future Compact Linear Collider(CLIC) running at■= 3 TeV. We consider two distinct scenarios. In the first, when the non-standard scalars are heavy, the dark resonance is intense enough to make its discovery possible at CLIC when the resonance mass is in the range [2000, 3000] GeV. In the second scenario, when the non-standard scalars are light, the new vector boson is too broad to be recognized as a resonance, and is not detectable except when the mass of the scalars is close to(but smaller than) half of the resonance mass and the scale of the dark sector is high. In all positive cases, less than a tenth of the maximum integrated luminosity is needed to reach the discovery level. Finally, we also comment on the mono-Z production.
基金Supported by National Natural Science Foundation of China(11175192)
文摘The Compact Linear Collider （CLIC） is a future e＋e linear collider. The CLIC study concentrated on a design of center-of-mass energy of 3 TeV and demonstrated the feasibility of the technology. However, the physics also demands lower energy collision. To satisfy this, CLIC can be built in stages. The actual stages will depend on LHC results. Some specific scenarios of staged constructions have been shown in CLIC Concept Design Report （CDR）. In this paper, we concentrate on the main linac lattice design for Ecm=l TeV CLIC aiming to upgrade from E~.,=500 GeV CLIC and then to Ecru=3 TeV one. This main linac accelerates the electron or positron beam froth 9 GeV to 500 GeV. A primary lattice design based on the 3 TeV CLIC main linac design and its optimization based on the beam dynamics study will be presented. As we use the same design principles as 3TeV CLIC main linac, this optimization is basically identical to the 3 TeV one. All the simulations results are obtained using the tracking code PLACET.
文摘The ability to visualise proteins in their native environment and discern information regarding stoichiometry is of critical importance when studying protein interactions and function. We have used liquid cell atomic force microscopy (AFM) to visualise proteins in their native state in buffer and have determined their molecular volumes. The human proteins S100A8, S100A9, S100A12 and CLIC1 were used in this investigation. The effect of oxidation on the protein structure of CLIC1 was also investigated and we found that CLIC1 multimerisation could be discerned by AFM, which supports similar findings by other methods. We have found good correlation between the molecular volumes measured by AFM and the calculated volumes of the individual proteins. This method allows for the study of single soluble proteins under physiological conditions and could potentially be extended to study the structure of these proteins when located within a membrane environment.
基金supported by the National Natural Science Foundation of China(NNSFC)under Grants No.11705048the National Research Project Cultivation Foundation of Henan Normal University under Grant Nos.2020PL16,2021PL10powered by the High Performance Computing Center of Henan Normal University。
文摘In a simplified model including an SU(2)singlet vector-like top quark T(VLT)with charge 2/3,we investigate the associated production of Wb with VLT at a Compact Linear Collider(CLIC).Focusing on the T→Wb decay channel,we discuss two decay models:e+e-→TW+b→(l-vb)(jjb)and e+e-→TW+b→(jjb)(l+νb).In this paper,we consider recent experimental limits including the electroweak precision observables,the width of the top quark,and the direct LHC searches.Through a detailed detector simulation,we show the exclusion and discovery capability on the T at 3 TeV CLIC,where the initial state radiation effect has also been considered.The results show that it is promising to detect the VLT at future high-energy e+e-colliders.
文摘From July 31st to August 1st,2018,the International Workshop on Cryospheric Changes and Their Regional and Global Impacts,co-sponsored by the State Key Laboratory of Cryospheric Science of Northwest Institute of Eco-Environment and Resources(NIEER),Chinese Academy of Sciences,People's Government of Dunhuang City,the International Association of Cryospheric Sciences(IACS),the World Climate Research Program Climate and Cryosphere(WCRP)/the Climate and Cryosphere(CliC),the University of Alaska Fairbanks and others,was successfully held in Dunhuang,Gansu Province.
基金Funded by Fujian Education Department(Nos.JA11329 and JA12412)Quanzhou(Fujian)Techno logy Research and Development Program(Nos.2013Z158,2013Z47,and 2010G7)
文摘Our research focused on the analy sis of concrete deterioration mechan ism under the coup ling effects of flexural load,cy clic wetting and dry ing, and sulfate. The relative dy namic modulus of elasticity of a corroded concrete samp le was tested, and scannin g electron microscop e was used to observe the microstructure of concrete under the coup ling effects of flexural load,cy clic wetting and dry ing, and sulf ate. Results manif ested that flexur al load and cy clic wetting and dry ing durin g the concrete service chan ged the corrosion p rocess of the sulfate mediu m in con crete and enh anced the deterioration of con crete p erforman ce.Furthermore, the influencin g p atterns of strength grade of concr ete, mass concentration of sulfate solution, and mineral admixtures on the degree of concrete deterioration were identified.
文摘In this study,light-by-light(LBL)scattering with initial polarized Compton backscattered photons at the CLIC,induced by axion-like particles(ALPs),is investigated.The total cross sections are calculated assuming CP-even coupling of the pseudoscalar ALP to photons.The 95%C.L.exclusion region for the ALP mass ma and its coupling constant f is presented.The results are compared with CLIC bounds previously obtained for the unpolar-ized case.It is shown that the bounds onf for the polarized beams in the region m_(a)=1000-2000 GeV with colli-sion energy of 3000 GeV and integrated luminosity of 4000 fb^(-1)are on average 1.5 times stronger than the bounds for the unpolarized beams.Moreover,our CLIC bounds are stronger than those for all current exclusion regions for m_(a)>80 GeV.In particular,they are more restrictive than the limits that follow from the ALP-mediated LBL scatter-ing at the LHC.
基金the National Natural Science Foundation of China(No.30470559,30330230,30240059)the National Basic Research Development Program(973)of China(No.2007CB512501)Beijing Natural Science Foundation(No.7052039)
文摘Dorsal root ganglion(DRG)neurons have peripheral terminals in skin,muscle,and other peripheral tissues,andcentral
文摘[目的]研究绞股蓝总皂苷(gypenosides,GPs)对RAW264.7细胞脂质累积及细胞内氯离子通道蛋白1(chloride intracellular channel 1,CLIC1)表达的影响,探讨GPs抗动脉粥样硬化的分子机制。[方法]将RAW264.7细胞接种于六孔板中,分为NC组、氧化型低密度脂蛋白(oxidized low density lipoprotein,ox-LDL)组、GPs 10组、GPs 50组、GPs 100组及CLIC1 si RNA组。各组细胞处理24h后,油红O染色检测各组细胞内脂质的累积,化学法检测细胞内总胆固醇(total cholesterol,TC)及游离胆固醇(free cholesterol,FC)的含量,荧光定量PCR和免疫印迹法检测CLIC1、CD36m RNA和蛋白质的表达,免疫荧光技术观察CLIC1的细胞定位,并用MQAE法检测细胞内氯离子浓度的变化。[结果]与NC组相比,ox-LDL组CLIC1、CD36 m RNA(P<0.01,P<0.001)及蛋白(P<0.01,P<0.001)表达水平显著升高,细胞内TC(P<0.001)、FC(P<0.01)显著升高,细胞膜上CLIC1表达显著升高,细胞内氯离子浓度显著增加(P<0.01);经CLIC1 si RNA或GPs处理后,细胞内TC(P<0.001,P<0.001)、FC(P<0.01,P<0.01)含量降低,脂质累积减少,CLIC1、CD36 m RNA及蛋白表达水平显著下调(P<0.01,P<0.001)。[结论]CLIC1在巨噬细胞脂质累积中发挥着重要的作用,GPs可以通过调控CLIC1的表达抑制巨噬细胞脂质累积。
文摘Systematic studies on the cryosphere in China started in the late 1950s. Significant achievements have been made by continuous investigation of glacier inventories, frozen ground observations, paleo-climate analyses of ice cores, process studies and the modeling of cryopsheric/atmospheric interactions. The general facts and understanding of these changes include： （1） Solid precipitation, including the number of days with frost and hail storms, shows a decreasing tendency over the past half century. （2） In most areas glaciers are retreating or have completely vanished （〉80%）, some glaciers are still advancing （5%-20% depending upon time period）. The annual glacial melt water has been increasing since the 1980s. This increased supply of melt water to river runoff in Northwest China is about a 10%-13%. （3） The long-term variability of snow cover in western China is characterized by a large inter-annual variation superimposed on a small increasing trend. Snow cover variability in the Qinghai-Xizang Plateau （QXP） is influenced by the Indian monsoon, and conversely impacts monsoon onset and strength and eventually the drought and flood events in middle-low reaches of Yangtze River. （4） Frozen ground, including permafrost, is decaying both in QXP and in Northeast China. The most significant changes occurred in the regions with thickest seasonal frozen ground （SFG）, i.e., inland QXP, then northeastern and northwestern QXP. The cold season air temperature is the main factor controlling SFG change. The increase of ground surface temperatures is more significant than air temperature. （5） The sea ice coverage over the Bohai Sea and Yellow Sea has deceased since the 1980s. （6） River ice duration and ice thickness is also decreasing in northern China. In 2001, the Chinese National Committee of World Climate Research Program/Climate and Cyosphere （WCRP/CliC） （CNC-CliC） was organized to strengthen research on climate and cryosphere in China. Future monitoring of the cryosphere
基金Supported by Ligue Contre le Cancer, Programme Hospitalier de Recherche Clinique (20-R6)
文摘AIM: To develop novel biomarkers of rectal radiotherapy, we measured gene expression profiles on biopsies taken before and during preoperative radiotherapy. METHODS: Six patients presenting with a locally advanced rectal cancer (T>T2, N0/Nx, M0) eligible for preoperative radiotherapy (45 Gy in 25 fractions) were selected in a pilot study. Six tumor and 3 normal tissues biopsies were taken before and during radiotherapy,after a dose of 7.2 Gy at a median time of 1 h following irradiation (0:27-2:12). Tumor or normal tissue purity was assessed by a pathologist prior to RNA extraction. Mean RNA content was 23 μg/biopsy (14-37) before radiotherapy and 22.7 μg/biopsy (12-35) during radiotherapy. After RNA amplification, biopsies were analysed with 54K HG-U133A Plus 2.0 Affymetrix expression micro-arrays. Data were normalized according to MAS5 algorithm. A gene expression ratio was calculated as: (gene expression during radiotherapy-gene expression before radiotherapy)/gene expression before radiotherapy. Were selected genes that showed a ratio higher than ± 0.5 in all 6 patients. RESULTS: Microarray analysis showed that preoperative radiotherapy significantly up-regulated 31 genes and down-regulated 6 genes. According to the Gene Ontology project classification, these genes are involved in protein metabolism (ADAMDEC1 ; AKAP7 ; CAPN5 ; CLIC5 ; CPE ; CREB3L1 ; NEDD4L ; RAB27A), ion transport (AKAP7 ; ATP2A3 ; CCL28 ; CLIC5 ; F2RL2 ; NEDD4L ; SLC6A8), transcription (AKAP7 ; CREB3L1 ; ISX ; PAB-PC1L ; TXNIP), signal transduction (CAPN5 ; F2RL2 ; RA- B27A ; TNFRSF11A), cell adhesion (ADAMDEC1 ; PXDN ; SPON1 ; S100A2), immune response (CCL28 ; PXDN ; TNFRSF11A) and apoptosis (ITM2C ; PDCD4 ; PVT1). Up-regulation of 3 genes (CCL28 ; CLIC5 ; PDCD4) was detected by 2 different probes and up-regulation of 2 genes (RAB27A ; TXNIP) by 3 probes. CONCLUSION: Micro-arrays can efficiently assess early transcriptomic changes during preoperative radiotherapy for rectal cancer, and may help better understand tumor radioresistance.
