长链非编码RNA XLOC_002319在食管鳞癌中表达及其甲基化状态

目的:通过检测食管鳞状细胞癌(esophageal squamous cell carcinoma,ESCC)中长链非编码RNA XLOC_002319(long non-colding RNA XLOC_002319,lncRNA XLOC_002319)基因的表达及其甲基化状态,探讨XLOC_002319基因在ESCC发生及发展中的作用.方法:分别应用RT-PCR以及甲基化特异性PCR(methylation specific PCR,MSP)的方法检测DNA甲基化转移酶抑制剂5-氮杂-2'-脱氧胞苷(5-aza-2'-deoxycitydine,5-aza-dC)处理前后的食管癌细胞株(TE1、TE13、Yes-2、Eca109和T.TN)、ESCC组织以及癌旁正常组织、食管上皮内瘤变(esophageal intraepithelial neoplasia,EIN)组织中XLOC_002319基因的表达和甲基化状态.结果:未经5-aza-dC处理的5种食管癌细胞中XLOC_002319基因的表达均呈阴性或弱阳性,经5-azadC的5种食管癌细胞中XLOC_002319基因的表达均增高.5株食管癌细胞在5-aza-dC处理前表现为XLOC_002319高甲基化状态,处理后,Eca109和T.TN细胞系中XLOC_002319基因甲基化程度降低,其余3株细胞系中XLOC_002319基因均表现为非甲基化状态.XLOC_002319基因在ESCC组织中的表达显著低于食管上皮内瘤变组织和癌旁正常组织(P＜0.01),并与组织学分化程度和TNM分期密切相关(P＜0.05).ESCC组织中XLOC_002319基因启动子区甲基化率为63.75％ (51/80),显著高于食管上皮内瘤变组织和癌旁正常组织(P＜0.01),并与淋巴结转移、组织学分化程度和TNM分期密切相关(P＜0.05).发生XLOC_002319基因甲基化的ESCC组织中XLOC_002319基因表达显著低于未发生甲基化的ESCC组织(P＜0.01).结论:XLOC_002319基因在ESCC中的低表达可能与ESCC的发生密切相关,且其启动子区甲基化可能是导致其表达沉默的机制之一.     

长链非编码RNA XLOC_005009在食管鳞状细胞癌中的表达及其甲基化状态

[目的]通过检测长链非编码RNA XLOC 005009在人食管癌细胞系及食管鳞状细胞癌(ESCC)组织中的表达情况及其甲基化状态,探讨XLOC_005009基因在食管鳞癌发生、发展中的作用及表观遗传学失活机制.[方法]分别应用逆转录一聚合酶链反应以及甲基化特异性聚合酶链反应的方法检测XLOC_005009基因在DNA甲基化转移酶抑制剂5-Aza-dC处理前后的食管癌细胞系(TE1、TE13、T.Tn、Eca109)以及57例食管鳞癌组织及相应癌旁正常组织中的表达情况和各位点的甲基化状态.[结果] XLOC_005009基因的表达在5-Aza-dC处理后的4株细胞系中表达增高,在5-Aza-dC处理前的4株细胞系中XLOC_005009基因的3个位点均表现为高甲基化状态,在5-Aza-dC处理后,各位点甲基化程度均降低.XLOC 005009基因在ESCC中的表达明显低于对应癌旁正常组织(0.21±0.22 vs 0.32±0.29,P＜0.05),其远端CpG岛及第2外显子区甲基化率在ESCC与其癌旁正常组织中差异无统计学意义,且其在发生甲基化的ESCC与未发生甲基化的ESCC中的表达无统计学差异.第一外显子区甲基化率在ESCC中显著高于其癌旁正常组织[45.61％(26/57)vs 19.30％(11/57),P＜0.05],并与淋巴结转移、组织分化程度及TNM分期密切相关,且此位点发生甲基化的ESCC中该基因的表达显著低于未发生甲基化的ESCC组织(0.06±0.06 vs 0.33±0.23,P＜0.05).[结论]XLOC_005009基因在食管癌细胞系和ESCC中的低表达与ESCC的发生、发展密切相关,且其第一外显子区甲基化异常增高可能是导致其表达沉默的机制之一.     

IGFBP3基因在食管鳞状细胞癌中的表达及甲基化状态

目的：检测食管鳞状细胞癌(esophageal squamous cell cancer, ESCC)中胰岛素样生长因子结合蛋白3(insulin-like growth factor binding protein 3, IGFBP3)基因的表达情况及甲基化状态,探讨其与ESCC发生发展的关系。方法：收集河北医科大学第四医院2008至2011年间的82例ESCC手术患者的ESCC原发灶组织及癌旁正常黏膜组织。RT-PCR及甲基化特异性-PCR(methylation specific-PCR, MSP)的方法分别检测DNA甲基转移酶抑制剂5-氮杂-2′-脱氧胞苷(5-aza-2′-deoxycitydine, 5-Aza-dC)处理前后的ESCC细胞系(TE1、TE13、YES-2、T.TN、Eca109)及82例ESCC及相应癌旁组织中 IGFBP3 基因mRNA表达水平及甲基化状态,应用免疫组织化学方法检测IGFBP3在ESCC组织中的蛋白表达情况,并分析 IGFBP3 基因甲基化状态与其表达水平之间的关系。 结果： 在ESCC细胞株TE1、TE13、YES-2、T.TN、Eca109中, IGFBP3 基因mRNA均呈阴性或弱阳性表达,用5-Aza-dC培养处理后,其mRNA表达水平均呈现不同程度的增高（P＜0.05）;MSP检测结果显示,在ESCC细胞株TE1、TE13、T.Tn、Yes-2中 IGFBP3基因均呈高甲基化状态。在ESCC组织中 IGFBP3 mRNA表达显著低于癌旁组织\[（0.15±0.07）vs（0.88±0.32）,P＜0.01\],且IGFBP3蛋白在癌组织中的表达阳性率显著低于癌旁组织\[29.3%（24/82）vs 84.1%（69/82）,P＜0.01\],并与TNM分期密切相关（P＜0.05）;IGFBP3基因在ESCC组织中的甲基率为68.3%（56/82）,明显高于癌旁组织的15.9%（13/82）（P＜0.01）;IGFBP3基因在Ⅲ和Ⅳ期肿瘤组织中的甲基化率明显高于Ⅰ和Ⅱ期肿瘤组织（P＜0.05）,而该基因的甲基化率与肿瘤患者的组织学分级无相关性（P> 0.05）。IGFBP3基因甲基化状态与其表达之间有明显的相关性(P＜0.05)。结论： ESCC组织及细胞株中IGFBP3基因呈高甲基化状态,该基因的甲基化可能导致其表达下调,并有可能是ESCC的发生机制之一。     

长链非编码RNA ZNF667-AS1在食管鳞状细胞癌组织中的表达及其DNA甲基化状态的研究

 目的 检测长链非编码RNA ZNF667-AS1在食管鳞状细胞癌（esophageal squamous cell carcinoma, ESCC）中的表达及甲基化状态。方法 应用qPCR和MSP法检测DNA甲基化转移酶抑制剂5-Aza-dC处理前后食管癌细胞系（Kyse170、Eca109、TE1和TE13）、ESCC及相应癌旁正常组织中ZNF667-AS1基因的表达,及其CpG岛三个区域的甲基化状态。结果 在5-Aza-dC处理后的四株细胞系中,ZNF667-AS1基因的表达均增高,且其CpG岛三个区域甲基化程度均降低。ZNF667-AS1基因在ESCC组织中的表达显著低于相应癌旁正常组织,且该基因CpG岛远端启动子区及第一外显子区甲基化率在ESCC与相应癌旁正常组织中的差异均具有统计学意义（均P<0.05）。ESCC组织中CpG岛近端启动子区甲基化率显著高于相应癌旁正常组织,并与组织分化程度、TNM分期密切相关,ZNF667-AS1基因CpG岛近端启动子区发生甲基化的ESCC组织中,低表达例数高于高表达例数,差异具有统计学意义。结论 ZNF667-AS1基因在食管癌细胞系和ESCC组织中的低表达与ESCC的发生发展密切相关,且其近端启动子区的高甲基化状态可能是导 致其表达沉默的机制之一。     

miR-6803和PPP6R1在食管鳞状细胞癌组织和细胞中的表达及其甲基化状态与患者临床病理特征的关系

目的:探讨微小RNA-6803(miR-6803)及其宿主基因蛋白磷酸酶6调节亚单位1(protein phosphatase 6 regulation subunit 1,PPP6R1)在食管鳞状细胞癌(ESCC)中的表达和PPP6R1基因启动子区甲基化状态及其在ESCC发生及发展中的作用.方法:采用2013年至2014年间河北医科大学第四医院生物标本库的72例ESCC手术患者癌组织及对应的癌旁组织标本,用实时荧光定量PCR法检测miR-6803和PPP6R1在ESCC组织及其癌旁组织和DNA甲基化转移酶抑制剂5-氮杂-2’-脱氧胞苷(5-Aza-dC)处理前后的ESCC细胞株TE1、TE13、Eca109、T.TN、Kyse170中的表达水平.用甲基化特异性PCR(MSP)法检测ESCC细胞系和组织及其癌旁组织中PPP6R1的甲基化状态,分析其与患者临床病理特征的关系.结果:ESCC组织中miR-6803和PPP6R1的表达水平显著低于癌旁组织(0.318±0.156,0.408±0.177 vs 1.000±0.001,均P＜0.05),miR-6803表达水平与淋巴结转移、组织分化程度及TNM分期密切相关(均P＜0.05);PPP6R1表达水平与TNM分期和组织学分化程度密切相关(均P＜0.05).ESCC组织中miR-6803和PPP6R1基因的表达具有显著相关性(P＜0.05).ESCC组织中PPP6R1的启动子区甲基化率显著高于癌旁组织(56.94％ vs 36.11％,P＜0.05),并与TNM分期和组织学分化程度密切相关(均P＜0.05),miR-6803-和PPP6R1基因的低表达与PPP6R1启动子区甲基化明显相关(P＜0.05).经5-Aza-dC处理后,5种ESCC细胞中miR-6803和PPP6R1的表达均升高,并且TE1、TE13、Kyse170细胞中PPP6R1基因甲基化程度降低,非甲基化程度增加,其余2种细胞中PPP6R1基因均表现为非甲基化状态.结论:miR-6803及其宿主基因PPP6R1的低表达可能与ESCC的发生发展密切相关,其启动子区甲基化可能是miR-6803和PPP6R1表达沉默的机制之一.     

MicroRNA-203在人食管鳞癌组织和细胞中的表达及其基因的甲基化状态

目的：检测人食管鳞状细胞癌（esophageal squamous cell carcinoma, ESCC）组织及细胞中MicroRNA-203(miR-203)的表达及其基因的甲基化状态,探讨miR-203在ESCC发生及发展中的作用。方法：选取河北医科大学第四医院2008—2011年间手术切除的83例ESCC原发灶组织及癌旁组织标本,实时定量PCR与甲基化特异性PCR（methylation specific PCR,MSP）分别检测其miR-203的表达及其编码基因的甲基化状态。用DNA甲基化转移酶抑制剂5-氮杂-2’-脱氧胞苷（5-aza-2’-deoxycitydine, 5-Aza-dC）处理食管癌细胞系（TE1、TE13、YES-2、EC109、T.TN）,实时定量PCR与MSP分别检测5-Aza-dC处理对食管癌细胞中miR-203的表达及其基因甲基化状态的影响。结果：五种食管癌细胞中miR-203的表达均相对较低,且呈高甲基化状态。5-Aza-dC处理后,miR-203的表达均显著升高（ P <0.05或 P <0.01）;YES-2细胞中miR-203编码基因的甲基化程度显著降低,其余4种细胞均转变为非甲基化状态。miR-203在ESCC组织中的表达显著低于癌旁组织（0.54±0.11 vs 1.00±001, P <0.01）,启动子区甲基化率显著高于癌旁组织\[62.65%（52/83) vs 7.23% (6/83）, P <0.01\],并且两者均与TNM分期和组织分化程度有关（ P<0.05）。发生miR-203编码基因甲基化的ESCC组织中miR-203的表达显著低于未发生甲基化的ESCC组织（ P <005）。结论： miR-203在ESCC组织与细胞中呈低表达,与食管鳞癌的发生、发展有关,且其启动子区甲基化可能是导致其表达沉默的机制之一。     

长链非编码RNA XLOC_002319在贲门腺癌中的表达及其甲基化状态

[目的]检测贲门腺癌(GCA)中长链非编码RNA XLOC_002319(lncRNA XLOC_002319)的表达及其甲基化状态,探讨XLOC _002319在贲门腺癌发生发展中的作用.[方法]分别应用实时荧光定量聚合酶链反应(qRT-PCR)以及甲基化特异性PCR(MSP)检测贲门腺癌组织、癌旁不典型增生组织及癌旁正常组织中XLOC_ 002319的表达和甲基化状态.[结果]XLOC_002319在贲门腺癌组织和癌旁不典型增生组织中的表达显著低于癌旁正常组织(P＜0.01),并且在贲门腺癌组织中XLOC_ 002319的表达与组织学分化程度、淋巴结转移和TNM分期密切相关(P＜0.05).贲门腺癌组织中XLOC _002319的启动子区甲基化率(61.54％)和癌旁不典型增生组织甲基化率(54.84％)显著高于癌旁正常组织(17.95％)(P＜0.01),并且贲门腺癌组织中XLOC_002319的启动子区甲基化率与组织学分化程度、淋巴结转移和TNM分期密切相关(P＜0.05).发生XLOC_002319甲基化的贲门腺癌组织中XLOC_002319的表达显著低于未发生甲基化的贲门腺癌组织(0.217±0.074 vs 0.253±0.060,P＜0.05).[结论]XLOC_002319在贲门腺癌中的异常低表达可能与贲门腺癌的发生密切相关,且其启动子区甲基化可能是导致其表达沉默的机制之一.     

食管鳞状细胞癌中Smad4基因CpG岛甲基化状态分析

目的：探讨食管鳞状细胞癌（esophageal squamous cell carcinoma,ESCC）中Smad4（mothers against decapentaplegic homolog 4）基因启动子区及第一外显子区的CpG岛甲基化状态及其与Smad4蛋白、TGF-β1蛋白表达之间的相关性。方法：128例ESCC组织标本采集自河北医科大学第四医院2004-2008年的手术病例,每例患者均取癌旁正常黏膜组织作对照。分别应用甲基化特异性PCR（methylmion specific PCR,MSP）、RT-PCR和免疫组织化学法检测ESCC组织及相应癌旁组织中Smad4基因CpG岛的甲基化情况、Smad4 mRNA和Smad4蛋白表达情况,应用免疫组织化学法检测TGF-β1的蛋白表达情况。结果：ESCC组织中Smad4基因启动子区CpG岛甲基化率为5.5%（7/128）,第一外显子5′非翻译区CpG岛甲基化率为305%（39/128）;相应癌旁正常黏膜组织均未检测到这两个位点的甲基化（P<0.05）;ESCC组织中Smad4甲基化率显著高于癌旁正常组织（P<005）。ESCC组织中Smad4 mRNA及蛋白表达显著低于癌旁正常组织（P<0.05）,且与Smad4甲基化相关。TGF-β1蛋白在ESCC组织中的表达率（66.4%）显著高于相应癌旁正常组织（21.9%,P<0.01）,且随ESCC分期的增高和分化程度的降低而升高（P<0.05）。Smad4和TGF-β1蛋白在ESCC中的表达呈明显的负相关（P<0.01)。结论: Smad4基因CpG岛甲基化及TGF-β1的过表达可能是ESCC发生机制之一,其中Smad4基因第一外显子5′非翻译区CpG岛比启动子区CpG岛更易发生甲基化,从而导致Smad4基因沉默。     

Ras相关区域家族7基因在食管鳞状细胞癌中的表达及其临床意义

目的：检测人食管鳞癌 (esophageal squamous cell carcinoma, ESCC)组织中Ras相关区域家族7（Ras-association domain family 7,RASSF7）基因的mRNA、蛋白表达情况及其甲基化状态,探究RASSF7 在ESCC发生发展中的作用。方法：组织标本取自河北医科大学第四医院2011—2012年间手术切除的69例ESCC原发灶组织及癌旁组织。分别应用RT-PCR及甲基化特异性PCR(methylation specific polymerase chain reaction,MSP)方法检测DNA甲基转移酶抑制剂5-氮杂-2’-脱氧胞苷（5-aza-2’-deoxycitydine, 5-Aza-dC）处理前后的4株食管癌细胞系（TE13、T.Tn、YES-2、Ec109）和69例病灶组织及其癌旁组织中RASSF7 mRNA表达水平及甲基化状态,应用免疫组织化学方法检测69例ESCC组织及相应癌旁组织中RASSF7的蛋白表达。结果：RASSF7基因在TE13、T.Tn、YES-2细胞系中表达阳性,在Ec109细胞系中表达缺失;经5-Aza-dC处理后,RASSF7在TE13、T.Tn、YES-2细胞中表达下调,在Ec109细胞中表达阳性。5-Aza-dC处理前后4株食管癌细胞系中均未检测到RASSF7 的甲基化。人ESCC组织中RASSF7 的mRNA相对表达量（0.63±0.08 vs 0.42±0.20,P<0.01）与蛋白表达阳性率\[81.2%（56/69） vs 53.6%（37/69）,P<0.01\]均显著高于相应癌旁组织,且均与患者的淋巴结转移情况及分化程度有关（P<0.05或P<001）,与TNM分期、年龄和性别无关（均P>0.05）。ESCC组织和相应癌旁组织中均未检测到RASSF7的甲基化。结论：4株食管癌细胞系、人ESCC组织和癌旁组织中RASSF7基因的表达差异与RASSF7 本身甲基化状态无关,ESCC组织中RASSF7 的高表达可能参与了ESCC的发生及转移。     

SHP-1 在食管鳞状细胞癌组织中异常低表达的表观遗传学调节机制及其临床意义

目的：探讨食管鳞状细胞癌（esophageal squamous cell carcinoma，ESCC）组织中蛋白酪氨酸磷酸酶1（protein tyrosin phosphatase 1，SHP-1）基因异常低表达的表观遗传学调节机制及其临床意义。方法：所用组织标本均来自河北医科大学第四医院2008-2011 年行食管癌根治术并且病理诊断为ESCC患者的癌组织及相应癌旁组织（距癌灶边缘2 cm以上），共71 例。ESCC细胞株（Eca109、Kyse170、Yes-2）培养完成后，进行甲基化抑制剂5-Aza-dC 或组蛋白去乙酰化酶抑制剂TSA处理，qPCR和Western blotting 实验检测ESCC组织和细胞系中SHP-1 mRNA和蛋白的表达变化，亚硫酸氢盐基因组测序（bisulfite genome sequencing，BGS）法检测ESCC 细胞系中SHP-1 基因启动子区CpG 位点的甲基化频率，甲基化特异性PCR（methylation specific PCR，MSP）技术检测ESCC组织和细胞中SHP-1 启动子区的甲基化状态，应用双荧光素酶报告基因实验检测SHP-1 启动子区CpG岛甲基化对其转录活性影响。分析ESCC组织中SHP-1 甲基化状态分别与临床病理特征和SHP-1 mRNA表达的关系，对组织SHP-1甲基化水平与ESCC患者生存率进行Kaplan-Meier 生存分析和Log-Rank 检验。结果:5-Aza-dC 处理后，SHP-1 mRNA蛋白在3种细胞株中的表达显著上调（均P<0.05），同时其启动子区的甲基化程度均明显降低(均P<0.05）；应用TSA处理细胞株后，SHP-1在各细胞株中的表达情况及甲基化状态无明显改变(P>0.05）；甲基转移酶处理细胞荧光素报告载体活性显著低于未处理细胞荧光素报告载体活性（P<0.05），表明SHP-1 的甲基化可抑制自身的转录。ESCC组织中启动子区的甲基化率明显高于癌旁组织（P<0.05），并与TNM分期、病理分级及淋巴结转移密切有关(P<0.05）；与癌旁组织相比，ESCC组织中SHP-1 mRNA相对表达量显著降低（P<0.05），并与启动子区甲基化有关（P<0.05）；Kaplan-Meier 分析显示，启动子区高甲基化与ESCC患者的不良预后有关（P<0.05）。结论：ESCC组织和细胞株中SHP-1 基因启动子区高甲基化状态可抑制其自身的转录活性，进而导致该基因表达沉默；SHP-1的高甲基化与ESCC患者预后不良有关，SHP-1 的甲基化状态可能成为ESCC患者预后的评估指标。     

New and emerging radiosensitizers and radioprotectors

The combination of chemotherapy and radiation has led to clinical breakthroughs in several disease sites, and current work continues to define optimum combinations of proven chemotherapy as well as more recently available, noncytotoxic agents. Administration of systemic therapies allows modulation of radiation response to improve tumor control (radiosensitization) or to prevent normal tissue toxicity (radioprotection). Substantial progress has been made in identifying the targets of standard chemotherapeutic radiation sensitizers and protectors as well as in the introduction of a new generation of molecularly targeted therapies in combination with radiation. We have reviewed the most recent, predominantly early phase clinical trials combining systemic agents with radiation. Although the proof of an improved schedule ultimately needs to come from well-run Phase III trials, the search among schedules could be shortened by the use of surrogate endpoints such as presence of active drug metabolites in the tumor. This has been accomplished only in a few cases and needs to become a more standard part of radiation sensitizer and protector trials.     

Religiosity and Physical and Emotional Functioning Among African American and White Colorectal and Lung Cancer Patients

The literature suggests that religiosity helps cope with illness. The present study examined the role of religiosity in functioning among African Americans and Whites with a cancer diagnosis. Patients were recruited from an existing study and mailed a religiosity survey. Participants (N = 269; 36% African American, 56% women) completed the mail survey, and interview data from the larger cohort was utilized in the analysis. Multivariate analyses indicated that in the overall sample religious behaviors were marginally and positively associated with mental health and negatively with depressive symptoms. Among women, religious behaviors were positively associated with mental health and negatively with depressive symptoms. Religiosity was not a predictor of study outcomes for men. Among African Americans, religious behaviors were positively associated with mental health and vitality. Among Whites, religious behaviors were negatively associated with depressive symptoms. These findings suggest a mixed role of religious involvement in cancer outcomes. The current findings may have applied potential in the areas of emotional functioning and depression.     

Fruit and vegetables and cancer risk

The possibility that fruit and vegetables may help to reduce the risk of cancer has been studied for over 30 years, but no protective effects have been firmly established. For cancers of the upper gastrointestinal tract, epidemiological studies have generally observed that people with a relatively high intake of fruit and vegetables have a moderately reduced risk, but these observations must be interpreted cautiously because of potential confounding by smoking and alcohol. For lung cancer, recent large prospective analyses with detailed adjustment for smoking have not shown a convincing association between fruit and vegetable intake and reduced risk. For other common cancers, including colorectal, breast and prostate cancer, epidemiological studies suggest little or no association between total fruit and vegetable consumption and risk. It is still possible that there are benefits to be identified: there could be benefits in populations with low average intakes of fruit and vegetables, such that those eating moderate amounts have a lower cancer risk than those eating very low amounts, and there could also be effects of particular nutrients in certain fruits and vegetables, as fruit and vegetables have very varied composition. Nutritional principles indicate that healthy diets should include at least moderate amounts of fruit and vegetables, but the available data suggest that general increases in fruit and vegetable intake would not have much effect on cancer rates, at least in well-nourished populations. Current advice in relation to diet and cancer should include the recommendation to consume adequate amounts of fruit and vegetables, but should put most emphasis on the well-established adverse effects of obesity and high alcohol intakes.     

VEGF及KDR在大肠腺瘤和腺癌中的表达及意义

目的：探讨VEGF和KDR在大肠腺瘤和大肠腺癌中的表达及临床病理特征的关系。方法：大肠腺瘤和大肠腺癌组织标本各100例,采用免疫组织化学染色法检测VEGF和KDR在标本中的表达情况。结果：VEGF和KDR在大肠腺癌组中的阳性表达明显高于大肠腺瘤组（P〈0.05）;在正常大肠黏膜均未见VEGF和KDR表达的阳性染色;VEGF阳性表达组中KDR的阳性表达率为70%,显著高于VEGF阴性表达组中KDR的阳性表达率16%,两组比较有统计学意义（P〈0.01）。结论：大肠腺癌组织中KDR的表达与肿瘤大小、转移情况、浸润深度密切相关;VEGF和KDR在大肠腺瘤中的表达与患者的年龄、性别及分型均无相关性,而与增生程度相关（P〈0.05）。在大肠腺癌患者中VEGF及KDR表达更高,二者具有协同效应。     

肾上腺素能β受体与肿瘤生长及转移

大量研究表明肿瘤细胞可表达β受体，而一些神经递质、药物和社会心理因素可能通过β受体影响肿瘤的生长和转移，β受体激动剂、β受体阻滞剂以及抑郁等社会心理因素可加强或削弱这种作用。这为表达β受体肿瘤的治疗开辟了新的道路，提供了新的治疗靶点。     

Occupational and environmental radiation and cancer

Epidemiologic evidence on the relation between occupational and environmental radiation and cancer is reviewed. Studies of pioneering radiation workers, underground miners, and radium dial painters revealed excess cancer deaths and contributed to the setting of radiation protection standards and to theories of carcinogenesis. Occupational exposures today are generally much lower than in the past, thus any associated increases in cancer will be difficult to detect. Pooling investigations of these more recently exposed workers, however, has the potential to validate current estimates of risk used in radiation protection. New information on the effects of chronic radiation exposure also may come from studies in the former Soviet Union of Chernobyl clean-up workers and of workers at the Mayak nuclear facilities. Studies of environmental radiation exposures, other than radon, are largely inconclusive, due mainly to the difficulties in detecting the low risks associated with low dose exposures. Thyroid cancer, however, has been linked to environmental radiation from the Chernobyl accident and from nuclear weapons tests. Low-level radiation released during normal operations at nuclear plants has not been found to increase cancer rates in surrounding populations. Radon, a human carcinogen, is the most ubiquitous exposure to human populations; remediating high residential-radon levels is recommended, recognizing that the exposure can never be removed completely because it occurs naturally.     

Cell and tissue interactions in carcinogenesis and metastasis and their clinical significance

This review describes a new vision for future directions in the study of metastatic cancer biology and pathology. It is based upon clinical and experimental observations on the constituent cell lineages within a neoplasm and on tumour-host interactions. The vision incorporates information from studies in population biology, developmental biology and experimental pathology as well as investigations upon human malignant disease. The assembled information reveals that invasion and metastasis are supra-cellular manifestations of "emergent behavior" among combinations of normal and malignant cell lineages in vivo. Emergent behavior is a combinatorial interactive process in which a population displays new traits which cannot be achieved by individuals acting separately and which subside when the specific population mix disaggregates. Disruption of such pathological interactions in the field of a developing primary or secondary tumour is, therefore, required to disable the malignant population and arrest progression without tissue destruction. These conclusions originate, in part, from principles which govern the sociobiology and group behavior of bees, ants, fish, birds and human societies. In all these social organisms, external factors can disrupt signaling mechanisms and induce expanding self-perpetuating rogue behavior, leading to social disintegration. These principles also apply to cellular societies composing higher animals, which likewise need intrinsic rules to maintain social order and avoid anarchy, and recognition of this is essential for advancing future research on the mechanisms involved in carcinogenesis and metastasis. Summarised evidence is presented here to support the conclusion that miscommunications between cells and tissues in the region of the developing tumour and its metastases are the main direct perpetrators of malignant disease. Genetic lesions (mutations, deletions, translocations, reduplications, etc.), commonly seen in cancers, can significantly disrupt important molecular pathways in the networks of communications needed to sustain orderly tissue/organ structure and function. However, genetic lesions can also, themselves, be induced by abnormal cell interactions initiated by extrinsic carcinogenic agents such as chemicals, viruses, hormones and radiation. The evidence shows that, irrespective of the initiating cause, it is this miscommunication in the region of a developing tumour and its metastases that is ultimately responsible for the emergence and progression of the disease. The article describes how this information collectively, provides a framework for designing specific novel therapeutic approaches targeting the cell and tissue interactions driving tumour metastasis and its manifold effects on the whole body.     

Vitamin D and melanoma and non-melanoma skin cancer risk and prognosis: A comprehensive review and meta-analysis

Vitamin D is formed mainly in the skin upon exposure to sunlight and can as well be taken orally with food or through supplements. While sun exposure is a known risk factor for skin cancer development, vitamin D exerts anti-proliferative and pro-apoptotic effects on melanocytes and keratinocytes in vitro. To clarify the role of vitamin D in skin carcinogenesis, we performed a review of the literature and meta-analysis to evaluate the association of vitamin D serum levels and dietary intake with cutaneous melanoma (CM) and non-melanoma skin cancer (NMSC) risk and melanoma prognostic factors. Twenty papers were included for an overall 1420 CM and 2317 NMSC. The summary relative risks (SRRs) from random effects models for the association of highest versus lowest vitamin D serum levels was 1.46 (95% confidence interval (CI) 0.60–3.53) and 1.64 (95% CI 1.02–2.65) for CM and NMSC, respectively. The SRR for the highest versus lowest quintile of vitamin D intake was 0.86 (95% CI 0.63–1.13) for CM and 1.03 (95% CI 0.95–1.13) for NMSC. Data were suggestive of an inverse association between vitamin D blood levels and CM thickness at diagnosis. Further research is needed to investigate the effect of vitamin D on skin cancer risk in populations with different exposure to sunlight and dietary habits, and to evaluate whether vitamin D supplementation is effective in improving CM survival.