miR-134靶向EGFR对非小细胞肺癌增殖的影响

目的 探讨微小RNA-134（miR-134）对非小细胞肺癌（NSCLC）细胞增殖和凋亡的影响及可能的机制。方法 采用实时荧光定量PCR（QPCR）检测miR 134在NSCLC细胞株（A549、H252）和正常胚肺细胞株WI38中的表达情况;将A549和H252细胞分为3组,分别为空白对照组（不转染）、miR-NC组（转染不相关siRNA）和miR-134组（转染miR-134 mimics）。分别于转染后24、48、72、96h收集细胞,采用MTS法检测细胞的增殖情况;转染后96h用流式细胞仪检测细胞的凋亡情况;双荧光素酶报告基因实验检测miR-134与表皮生长因子受体（EGFR）3’UTR的结合情况,QPCR检测过表达miR-134的A549和H252细胞中EGFR的表达情况。结果 与WI38 细胞相比,miR-134在A549细胞中的表达下调85.91％,在H252细胞中下调78.13％（P＜0.05）。MTS检测显示,miR-134能显著降低A549和H252细胞的增殖能力,并呈时间依赖性。流式细胞仪检测显示,与空白对照组比较,miR-134组A549细胞的凋亡比例提高226.31％,H252细胞提高47.85％（P＜0.05）。双荧光素酶报告基因实验显示miR 134能与EGFR3’UTR结合,显著降低荧光值（P＜0.05）。QPCR检测显示,与空白对照组比较,转染miR-134 mimics 后,EGFR在A549细胞中的相对表达量下调57.0％,在H252中下调35.0％,差异均有统计学意义（P＜0.01）。结论 miR-134在NSCLC中低表达,能通过靶向EGFR抑制NSCLC细胞增殖,并诱导凋亡。     

miR-125a-5p通过靶向APAF1 增强非小细胞肺癌细胞吉非替尼耐药性

目的：探讨miR-125a-5p 在诱导非小细胞肺癌（non-small cell lung cancer，NSCLC）细胞吉非替尼（gefitinib，Gef）耐药中的作用及其机制。方法：选用人NSCLC 耐药细胞株A549/GR 和NSCLC细胞株A549，将miR-125a-5p mimic、miR-125a-5p inhibitor、pcDNA3.1-APAF1、空载体pcDNA3.1 转染至A549/GR细胞。用qPCR检测细胞中miR-125a-5p 的表达水平，用MTT法、Transwell 小室法和流式细胞术检测Gef 对细胞增殖、迁移和凋亡的影响。用双荧光素酶报告基因实验验证miR-125a-5p 与细胞凋亡蛋白酶活化因子1（apoptotic peptidase activating factor 1，APAF1）的靶向关系，用Western blotting检测A549/GR细胞中APAF1蛋白水平，用比色法测定细胞中caspase-3 及caspase-9 表达水平。结果：A549/GR 细胞中miR-125a-5p 表达水平显著高于A549 细胞（P<0.01）。敲降miR-125a-5p 显著增强Gef 对A549/GR细胞增殖、迁移的抑制作用（均P<0.05），并促进细胞凋亡（P<0.01）。双荧光素酶报告基因实验证实miR-125a-5p 靶向APAF1，并负调控其表达。进一步实验显示，miR-125a-5p 通过靶向下调APAF1 缓解Gef 对A549/G 细胞增殖、迁移的抑制作用及凋亡的促进作用（均P<0.05），减弱Gef引起的凋亡相关蛋白caspase-3及caspase-9表达的上调（均P<0.05）。结论：miR-125a-5p 促进NSCLC细胞Gef 耐药，其机制是通过靶向APAF1 而促进细胞的增殖、迁移并抑制凋亡。     

miRNA-451逆转非小细胞肺癌A549／DDP细胞对顺铂的耐药性及其机制研究’

目的：探讨microRNA-451（miR-451）逆转非小细胞肺癌A549／DDP细胞对顺铂的耐药性及其可能的作用机制。方法：应用实时荧光定量PCR法（real～timefluorescentquantitativePCR,qRT—PCR）检测耐DDP细胞株A549／DDP及其亲本细胞株A549中miR-451的表达差异,同时检测A549／DDP细胞转染miR-451mimic后miR-451表达的变化;分别应用MTT法、克隆形成实验、流式细胞术检测转染后A549／DDP细胞对DDP药物敏感度,细胞增殖能力,联合DDP处理后细胞凋亡变化;Western印迹法检测转染后A549／DDP细胞Akt、P—Akt（Ser473）、bcl-2和bax的表达变化。结果：miR-451在耐DDP细胞株A549／DDP中的表达量显著低于敏感细胞株A549（P〈0．05）,A549／DDP细胞转染miR-451mimic24h后,细胞中miR-451的表达水平较对照组明显提高（P〈0．05）。在A549／DDP细胞中过表达miR-451可产生以下效应：相较于对照组,DDP对A549／DDP／miR-451细胞的半数抑制浓度（half inhibitioncon centration,IC50）减低（P〈0．05）,A549／DDP／miR-451细胞的增殖能力减弱,A549／DDP／miR-451经过DDP处理后细胞凋亡增多（P〈0．05）。Western印迹法结果显示,与对照组比较,转染miR-451mimic的A549／DDP细胞P—Akt（Ser473）、bcl-2表达水平降低;bax表达水平升高。结论：miR-451可能通过诱导细胞凋亡,抑制细胞增殖,上调bax蛋白及下调P—Akt（Ser473）、bcl-2蛋白表达而逆转A549／DDP细胞对DDP的耐药性。     

延龄草总皂苷调控hsa_circ_0025033/miR-149对非小细胞肺癌细胞生物学行为的影响

目的:研究延龄草总皂苷对非小细胞肺癌(non-small cell lung cancer,NSCLC)细胞A549增殖、凋亡、迁移和侵袭的影响。方法:将不同浓度的延龄草总皂苷作用于A549细胞,应用实时定量PCR检测hsa_circ_0025033和miR-149的表达,应用双荧光素酶基因系统验证hsa_circ_0025033与miR-149的靶向关系。分析干扰hsa_circ_0025033表达对A549细胞增殖、凋亡、迁移和侵袭的影响。结果:延龄草总皂苷可抑制A549细胞增殖、迁移和侵袭,诱导细胞凋亡,下调hsa_circ_0025033表达,上调miR-149表达(P＜0.05)。干扰hsa_circ_0025033可抑制A549细胞增殖、迁移和侵袭,诱导细胞凋亡(P＜0.05)。hsa_circ_0025033可靶向结合miR-149,干扰hsa_circ_0025033表达可上调miR-149表达(P＜0.05)。过表达hsa_circ_0025033逆转延龄草总皂苷对A549细胞增殖、凋亡、迁移和侵袭的影响(P＜0.05)。结论:延龄草总皂苷能够抑制NSCLC细胞A549增殖、迁移和侵袭,诱导细胞凋亡,可能与调节hsa_circ_0025033/miR-149通路有关。     

miR-492对非小细胞肺癌细胞迁移及侵袭能力的影响

目的:探讨miR-492对非小细胞肺癌（non-small cell lung cancer,NSCLC）细胞迁移和侵袭能力的影响,并探讨其可能的作用机制。方法:RT-qPCR检测NSCLC组织及细胞株（Calu-1、A549、H1650和H1299）中miR-492的表达。A549细胞瞬时转染miR-492 mimics或miR-492 inhibitors,并通过划痕实验及Transwell实验检测细胞的迁移及侵袭能力。双荧光素酶实验证实miR-492调控的靶基因。结果:NSCLC组织及细胞株中miR-492表达明显升高。将miR-492 mimics转染A549细胞后,细胞的迁移和侵袭能力明显增强。将miR-492 inhibitors转染A549细胞后,细胞的迁移和侵袭能力明显减弱。PTPN9是miR-492的直接靶基因。结论:miR-492可能通过调节靶基因PTPN9,从而促进NSCLC细胞的迁移和侵袭。     

选择性COX-2抑制剂对非小细胞肺癌细胞株毒性及分子机制的研究

目的：探讨选择性环氧化酶-2（cyclooxy-genase-2,COX-2）抑制剂Celecoxib对非小细胞肺癌（non-small cell lung cancer,NSCLC）细胞株增殖与凋亡的作用以及相关分子机制。方法：对3种NSCLC细胞株A549（腺癌）、GLC82（腺癌）和SW1573（肺泡细胞癌）使用MTT法测定细胞生长抑制率;Hoechest33258荧光染色观察细胞凋亡;流式细胞仪分析细胞凋亡及细胞周期分布;West-ern blot法检测COX-2、磷酸化AKT（p-AKT）、总丝苏氨酸激酶（serine/threonine kinase,AKT）、磷酸化ERK（p-ERK）及总细胞外信号调节激酶（ex-tracellular signal-regulated kinase,ERK）蛋白的表达。结果：Celecoxib抑制A549、GLC82和SW1573细胞增殖的IC50值分别为14.7、10.6和18.6μmol/L;Celecoxib对3种NSCLC细胞株都有较明显的凋亡诱导作用,Celecoxib作用12h凋亡率增加,24～48h更明显,Celecoxib10～40μmol/L作用可见凋亡率明显增加;Celecoxib作用于GLC82细胞后检测到胞内p-AKT及p-ERK蛋白表达下调。结论：COX-2抑制剂Celecoxib在体外能抑制细胞信号传导AKT及ERK通路的活化,诱导NSCLC细胞发生凋亡,抑制细胞增殖。     

miR-769-5p在非小细胞肺癌中的表达及其对细胞增殖、迁移与侵袭能力的影响

目的 探讨微小RNA-769-5p （miR-769-5p） 在非小细胞肺癌（NSCLC）细胞株中的表达及其对细胞增殖、迁移和侵袭能力的影响。方法 采用实时荧光定量PCR（QPCR）技术检测miR-769-5p 在5种NSCLC细胞（A549、NCI-H1299、NCI-H157、ANIP-973和GLC-82）中的相对表达量,选择相对表达量最低和最高的细胞株分别转染miR-769-5p mimics／miR-769-5p inhibitor,另设miRNA mimics control／inhibitor control对照组;采用MTS 实验、克隆形成实验及Transwell 小室实验检测miR-769-5p对NSCLC 细胞增殖、克隆形成、侵袭和迁移能力的影响。结果 miR-769-5p在A549、NCI-H1299、NCI-H157、ANIP-973 及GLC-82细胞中的相对表达量分别为 0.06、0.40、0.09、1.04和2.31。在miR-769-5p表达水平最低的A549细胞中瞬时转染miR-769-5p mimics,在miR-769-5p表达水平最高的GLC-82细胞中瞬时转染miR-769-5p inhibitor。MTS结果显示,与对照组比较,miR-769-5p mimics 能够抑制A549细胞的增殖 （P＜0.05）,而miR-769-5p inhibitor能够促进GLC-82细胞的增殖 （P＜0.05）。平板克隆实验结果显示,与对照组比较,miR-769-5p mimics 能够抑制A549细胞的平板克隆形成数 （124.7±14.7 vs. 399.4±46.0,P＜0.05）;而miR-769-5p inhibitor能够促进GLC-82细胞的平板克隆形成数 （555.7±29.7 vs. 366.3±28.7,P＜0.05）。Transwell实验结果显示,与对照组迁移和侵袭跨膜细胞数比较,miR-769-5p mimics能够抑制A549细胞的迁移和侵袭 （94.4±18.1 vs. 157.8±22.9,84.4±15.1 vs. 135.6±16.7,P＜0.05）;miR-769-5p inhibitor能够促进GLC-82细胞的迁移和侵袭 （226.7±40.3 vs. 153.3±38.7,196.7±39.1 vs. 138.9±40.4,P＜0.05）。结论 miR-769-5p可以抑制NSCLC细胞的增殖、侵袭和迁移,可能成为NSCLC的潜在靶点。     

miR-140-5p靶向HDAC7抑制非小细胞肺癌细胞增殖、迁移和侵袭的机制探讨

目的:探讨miR-140-5p靶向组蛋白去乙酰化酶7(histone deacetylase 7,HDAC7)调控非小细胞肺癌（non-small cell lung cancer,NSCLC）细胞增殖、迁移和侵袭的机制。方法:采用qRT-PCR检测人NSCLC组织及癌旁组织中miR-140-5p的表达水平。用miR-140-5p mimic（模拟物）及miR-140-5p NC（阴性对照）转染A549细胞,CCK8法及克隆形成实验检测细胞增殖能力,划痕实验和Transwell实验检测细胞迁移和侵袭能力,双荧光素酶报告基因实验验证miR-140-5p与HDAC7的靶向关系,Western blot检测各组细胞HDAC7及PI3K、p-PI3K、AKT、和p-AKT表达水平。结果:与癌旁组织相比,miR-140-5p在NSCLC组织中的表达水平明显减低,差异有统计学意义（P＜0.01）。与miR-140-5p NC组相比,过表达miR-140-5p后A549细胞在48和72 h的增殖能力明显降低（P＜0.05）;且细胞克隆形成、细胞迁移和侵袭能力均降低（均P＜0.05）,PI3K/AKT信号通路中关键分子p-PI3K和p-AKT蛋白水平明显降低（均P＜0.05)。生物信息学预测HDAC7可能是miR-140-5p的一个靶基因,且双荧光素酶报告结果证实miR-140-5p直接靶向调节HDAC7表达。结论:miR-140-5p通过靶向HDAC7表达进而抑制NSCLC A549细胞的增殖、迁移和侵袭,其机制可能与通过抑制PI3K/AKT信号通路的激活有关。     

miR-30a通过靶向调控ZEB2抑制非小细胞肺癌的迁移与侵袭

目的:探讨miR-30a在非小细胞肺癌(non-small cell lung cancer,NSCLC)细胞中的表达情况及miR-30a在肺癌细胞迁移和侵袭过程中的作用及其机制。方法:采用qRT-PCR检测miR-30a在不同NSCLC细胞株中的表达情况;采用脂质体2000转染miR-30a mimics和E盒结合锌指蛋白2（E-box binding zinc finger protein 2,ZEB2） siRNA;通过qRT-PCR检验miR-30a mimics和ZEB2 siRNA的转染效率及转染后ZEB2 mRNA的表达水平变化;Western blot检测转染miR-30a mimics和ZEB2 siRNA后ZEB2蛋白表达情况;采用双荧光素酶报告实验验证miR-30a和ZEB2的相互作用机制;划痕实验和Transwell小室侵袭实验检测上调miR-30a和干扰ZEB2对A549细胞迁移和侵袭能力的影响。结果:实验结果显示,与正常人支气管上皮细胞相比,在不同NSCLC细胞株中miR-30a的表达呈不同程度下调;NSCLC细胞转染miR-30a mimics和ZEB2 siRNA后均获得满意的转染效果:miR-30a mimics和ZEB2 siRNA明显降低了NSCLC细胞中ZEB2的mRNA和蛋白的表达水平,组间差异具有统计学意义。双荧光素酶报告实验验证miR-30a对ZEB2 3' UTR具有直接调控作用。细胞迁移实验和侵袭实验结果显示,与Blank组和NC组相比,miR-30a过表达组和ZEB2基因沉默组的A549细胞迁移和侵袭能力均明显降低,说明miR-30a mimics和ZEB2 siRNA均对A549细胞细胞迁移和侵袭有抑制作用。结论:上调miR-30a的表达水平可以负调控ZEB2转录后表达水平,通过抑制上皮-间质转化(epithelial-mesenchymal transition,EMT)的进程来抑制肺癌细胞的转移和侵袭。     

miR-101通过靶向FGF2抑制非小细胞肺癌的迁移和侵袭

目的：探究microRNA-101 (miR-101)通过靶向成纤维细胞生长因子2（fibroblast growth factor 2,FGF2）抑制非小细胞肺癌（non-small cell lung cancer,NSCLC）细胞迁移和侵袭的分子机制。方法：采用qPCR法检测人正常肺上皮细胞BEAS-2B和NSCLC细胞系A549、H661和SK-MES-1,以及转染后A549细胞miR-101和FGF2的表达水平。分别将miR-NC、miR-101 mimics、miR-IN-NC、miR-101 inhibitor或pcDNA-3.1空质粒、pcDNA-FGF2转染至A549细胞,运用划痕愈合实验和Transwell小室实验,检测A549细胞中过表达miR-101和FGF2对NSCLC细胞迁移和侵袭能力的影响,采用Western blotting（WB）法检测各组A549细胞中FGF2、E-cadherin、N-cadherin、Vimentin、ERK1/2和p-ERK1/2的表达水平。结果：miR-101在NSCLC细胞系中的表达水平明显低于正常肺上皮细胞（均P<0.05）,而以A549细胞中表达水平为最低。过表达miR-101可明显抑制A549细胞的迁移（P<0.05）和侵袭（P<0.01）,且使细胞中E-cadherin的表达增多（P<0.05）而Vimentin（P<0.05）、N-cadherin（P<0.01）和p-ERK1/2（P<0.05）的表达水平降低。抑制miR-101表达后,可以显著增强A549细胞的迁移和侵袭能力（均P<0.05）,引起细胞中E-cadherin表达明显降低而 Vimentin、N-cadherin 和 p-ERK1/2 表达水平增高（均 P<0.05）。采用 WB 法和双荧光素酶报告基因实验验证了 FGF2 是miR-101的直接靶基因,且过表达FGF2后显著增强A549细胞的迁移和侵袭能力（均P<0.01）,以及减少细胞中E-cadherin的表达（P<0.01）而增加Vimentin（P<0.01）、N-cadherin（P<0.05）和p-ERK1/2（P<0.05）表达水平。与单独过表达FGF2组相比,共同过表达miR-101和FGF2组A549细胞迁移和侵袭能力明显减弱（均P<0.01）,其E-cadherin的表达增多（P<0.01）而Vimentin（P<0.01）、N-cadherin（P<0.05）和p-ERK1/2表达水平下降（P<0.01）。结论：miR-101通过调控靶基因FGF2抑制NSCLC A549细胞的上皮间质转化（EMT）过程及ERK信号通路,进而抑制NSCLC细胞的迁移和侵袭。     

Cytologic classification of precancer and cancer of the endometrium and esophagus and of malignant lymphomas

The paper discusses cytological classifications of precancer and cancer of the endometrium, esophagus and malignant lymphomas presented by cytologists from five Soviet research institutes of oncology. The classifications were based on the data of 4400 cases in conformity with WHO histologic classifications.     

E-钙粘蛋白及PTEN基因编码蛋白与胃癌浸润转移

目的:观察抑癌基因PTEN蛋白和ECD在胃癌组织中的表达,探讨其与胃癌生物学行为及预后的关系。方法:以兔抗人PTEN多克隆抗体、鼠抗人ECD单克隆抗体,采用SABC免疫组化法,检测100例胃癌手术切除标本中拟测指标的表达。以χ2和Logrank检验对结果做统计学分析。结果:ECD、PTEN蛋白在非癌胃粘膜中均见表达;在胃癌组织中表达下调或缺失。ECD异常表达率为42.0%;弥漫型胃癌异常表达率(48.57%),明显高于肠型胃癌(26.67%),(P<0.05);ECD异常表达与浸润深度有关(P<0.05)。胃癌组织中PTEN蛋白缺失率为59%;弥漫型胃癌缺失率(65.71%)明显高于肠型胃癌(43.33%),(P<0.05);伴淋巴结转移的胃癌缺失率(64.47%)明显高于无淋巴结转移者(41.67%),(P<0.05);PTEN蛋白缺失的患者比阳性表达者预后差(P=0.0066)。65.85%PTEN阳性表达者同时伴ECD正常表达。结论:两种标志物与胃癌浸润转移有关,PTEN表达与胃癌患者预后密切相关。将两种指标联合检测,可作为正确判断胃癌患者预后,指导临床治疗的分子生物学指标。     

Schwannomas of Head and Neck and Review of Literature

Benign nerve cell tumours have been given various names like schwannoma, neurilemmoma, neurinoma, neurofibroma, spindle cell tumours etc. Extra cranial head and neck schwannomas usually present as solitary and well-demarcated lesions. The lesion can cause secondary symptoms, such as nasal obstruction, dysphasia, and hoarseness, depending upon the location of the lesion. Fine needle aspiration cytology, CT scans, and MRI may be of limited help in the diagnosis of schwannomas. The treatment is complete surgical excision of the benign tumour and postoperative histopathological examination establishes the final diagnosis.     

世界卫生组织骨质疏松症防治工作报告和防治建议

引 言 作为对第51号综合处理非传染性疾病预防与控制的世界卫生组织决议的反应,1998年7月WHO成立了致力于不断完善对骨质疏松预防和治疗策略的工作小组。小组成员来自世界各国致力于骨质疏松研究的知名专家。Harry K.Genant为本届主席。这一项世界范围内的骨质疏松教育计划旨在通过世界范围的研究,不断改善对骨质疏松的诊断水平和发展并完善对骨质疏松病人的合理治疗。其重点将以发展中国家为主。并为各国政府及其卫生部门和病人群体提供世界性有关骨质疏松症的总体的、完整的指导性资料。该项研究、教育计划的实施将由世界各国的骨质疏松症研究和治疗机构共同完成,并经权威学术机构、政府和非政府组织进行有针对性的回顾研究,最终由WHO审议通过。     

A comparative study of knowledge and awareness of colorectal and breast cancerA comparative study of knowledge and awareness of colorectal and breast cancer

Aims: To assess and compare knowledge and awareness of colorectal cancer and breast cancer in a sample of the general population. Methods: Eleven hundred visitors to six different outpatient clinics, in a University Hospital, were given a study-specific questionnaire, based on educational material from the British Association of Cancer United Patients (CancerBACUP). The questionnaire consisted of 12 statements on the incidence, presentation, detection, treatment and prognosis of colorectal and breast cancer. Results: One thousand and sixty-eight individuals returned the questionnaire. One thousand and four completed questionnaires were analysed. The mean age (SD) of respondents was 50.1 (17.2) years, and the male to female ratio was 2:3. Respondents had read more about breast than about colorectal cancer (60.3%vs 32.4%,P <0.0001, McNemar's test). The proportion of correct answers for each statement on breast cancer was higher than for answers to corresponding items on colorectal cancer. Mean overall scores (95% CI) for breast and colorectal cancer were 88.1 (86.9, 89.2) and 64.4 (62.5, 66.3) respectively, the mean difference (95% CI) being 23.7 (22.0, 25.5). Scores were higher for breast cancer irrespective of age or gender. Conclusion: There is a low level of understanding of colorectal cancer in the general population when compared to breast cancer. This highlights the importance of public education in this common cancer.     

Quality of life and care in leukemia,myeloma and non-malignant disease. Opinions of patients and relatives,and effects of geography and time

In a questionnaire study 140 subjects answered 4200 questions in 1980 and 1986. They consisted of patients with myeloma, acute leukemia, lung carcinoma, and non-malignant disease and their relatives. In 22 additional cases the questionnaire was not answered. The results show that myeloma patients are less content with the general care than leukemia patients (P < 0.05). Similarly, relatives of deceased myeloma patients are less satisfied with the information given to them than relatives of deceased leukemia patients (P < 0.001). The information has improved with time, however, since the patients were more satisfied in 1986 than in 1980 (P < 0.001) and relatives of myeloma patients still alive were more satisfied than relatives of patients who had died earlier (P < 0.001).     

Prospective study of fruit and vegetable consumption and incidence of colon and rectal cancers

BACKGROUND: Frequent consumption of fruit and vegetables has been associated with a reduced risk of colorectal cancer in many observational studies. METHODS: We prospectively investigated the association between fruit and vegetable consumption and the incidence of colon and rectal cancers in two large cohorts: the Nurses' Health Study (88 764 women) and the Health Professionals' Follow-up Study (47 325 men). Diet was assessed and cumulatively updated in 1980, 1984, 1986, and 1990 among women and in 1986 and 1990 among men. The incidence of cancer of the colon and rectum was ascertained up to June or January of 1996, respectively. Relative risk (RR) estimates were calculated with the use of pooled logistic regression models accounting for various potential confounders. All statistical tests were two-sided. RESULTS: With a follow-up including 1 743 645 person-years and 937 cases of colon cancer, we found little association of colon cancer incidence with fruit and vegetable consumption. For women and men combined, a difference in fruit and vegetable consumption of one additional serving per day was associated with a covariate-adjusted RR of 1.02 (95% confidence interval [CI] = 0.98-1.05). A difference in vegetable consumption of one additional serving per day was associated with an RR of 1.03 (95% CI = 0.97-1.09). Similar results were obtained for women and men considered separately. A difference in fruit consumption of one additional serving per day was associated with a covariate-adjusted RR for colon cancer of 0.96 (95% CI = 0.89-1.03) among women and 1. 08 (95% CI = 1.00-1.16) among men. For rectal cancer (total, 244 cases), a difference in fruit and vegetable consumption of one additional serving per day was associated with an RR of 1.02 (95% CI = 0.95-1.09) in men and women combined. None of these associations was modified by vitamin supplement use or smoking habits. CONCLUSIONS: Although fruits and vegetables may confer protection against some chronic diseases, their frequent consumption does not appear to confer protection from colon or rectal cancer.