No association between cyclooxygenase-2 and uridine diphosphate glucuronosyltransferase 1A6 genetic polymorphisms and colon cancer risk

AIM：To investigate the association of variations in the cyclooxygenase-2 （COX2） and uridine diphosphate glucuronosyltransferase 1A6 （UGTIA6） genes and non-steroidal anti-inflammatory drugs （NSAIDs） use with risk of colon cancer.METHODS： NSAIDs, which are known to reduce the risk of colon cancer, act directly on COX2 and reduce its activity. Epidemiological studies have associated variations in the COX2 gene with colon cancer risk, but others were unable to replicate this finding. Similarly,enzymes in the UGT1A6 gene have been demonstrated to modify the therapeutic effect of NSAIDs on colon adenomas. Polymorphisms in the UGTIA6 gene have been statistically shown to interact with NSAID intake to influence risk of developing colon adenomas, but not colon cancer. Here we examined the association of tagging single nucleotide polymorphisms （SNPs） in the COX2 and UGTIA6 genes, and their interaction with NSAID consumption, on risk of colon cancer in a population of 422 colon cancer cases and 481 population controls.RESULTS： No SNP in either gene was individually statistically significantly associated with colon cancer, nor did they statistically significantly change the protective effect of NSAID consumption in our sample. Like others, we were unable to replicate the association of variants in the COX2 gene with colon cancer risk （P 〉 0.05）,and we did not observe that these variants modify the protective effect of NSAIDs （P 〉 0.05）. We were able to confirm the lack of association of variants in UGT1A6 with colon cancer risk, although further studies will have to be conducted to confirm the association of these variants with colon adenomas.CONCLUSION： Our study does not support a role of COX2 and UGTIA6 genetic variations in the development of colon cancer.

No association between phosphatase and tensin homolog genetic polymorphisms and colon cancer

AIM: To investigate the association between single nucleotide polymorphisms (SNPs) in the phosphatase and tensin homolog (PTEN) tumor suppressor gene and risk of colon cancer. METHODS: We utilized a population-based casecontrol study of incident colon cancer individuals (n= 421) and controls (n = 483) aged ≥ 30 years to conduct a comprehensive tagSNP association analysis of the PTEN gene. RESULTS: None of the PTEN SNPs were statistically significantly associated with colon cancer when controlled for age, gender, and race, or when additionally adjusted for other known risk factors (P > 0.05). Haplotype analyses similarly showed no association between the PTEN gene and colon cancer. CONCLUSION: Our study does not support PTEN as a colon cancer susceptibility gene.

Advancements in Lynch Syndrome Management: Applying Immunotherapy for Therapeutic Success

Lynch syndrome is the fourth most common cancer in the United States, with an early age of onset and poor prognosis. Here, we present a unique case of a patient with progressive colon cancer due to a late diagnosis of Lynch syndrome showing excellent response to immunotherapy. A 59-year-old male with a history of rectal cancer 30 years ago came to the hospital due to a fever and further found a large necrotic colon mass. Biopsy was positive for colorectal cancer;however, due to the size of the tumor, the patient was deemed not a surgical candidate and offered hospice with palliative chemotherapy. Based on further workup, the patient was diagnosed with Lynch syndrome, with colon cancer determined to be responsive to Immunotherapy. He was started on JEMPERLI (Dosterlimab-gxly), and after three cycles of therapy, imaging and PET scan were repeated, showing decreased activity and extent of the tumor—a tremendous success.

Polymorphism of thymidylate synthase gene associated with its protein expression in human colon cancer

AIM： To correlate the polymorphisms in the 5＇-untranslated region with thymidylate synthase （TS） protein expression in Han Chinese colonic neoplasms. METHODS： Adenocarcinoma samples were from 68 patients who received no treatment before surgery. Tandem repeat length of TS gene was determined by PCR amplification of genomic DNA. Intratumoral TS protein expression was studied immunohistochemically in corresponding sections from paraffin-embedded primary loci. Immunoreactivity was semiquantitatively evaluated by immunoreactivity score （IRS）. RESULTS： Double-（2R） and triple-repeated （3R） sequences of the TS gene were found in the cancer tissues. Three genotypes of TS were found： 2R/2R （n = 6）, 2R/3R （n = 22） and 3R/3R （n = 40）. Patients who were homozygous for triple-repeated （3R/3R） sequences showed significantly higher IRS of TS than patients who were homozygous for double-repeated （2R/2R） sequences or heterozygous patients （2R/3R）： 5.73 ±3.25 vs 2.17 ± 1.47 or 3.77 ±2.64, P = 0.008 or P = 0.015. But no statistical significance of IRS in cancer tissues was observed between 2R/3R genotype and 2R/2R genotype. CONCLUSION： There is a relationship between TS genotype and TS protein expression in clinical specimens. The data might offer an advantage for selection of Chinese cancer patients to receive fluoropyrimidines treatment.

Diet,ageing and genetic factors in the pathogenesis of diverticular disease

Diverticular disease(DD) is an age-related disorder of the large bowel which may affect half of the population over the age of 65 in the UK.This high prevalence ranks it as one of the most common bowel disorders in western nations.The majority of patients remain asymptomatic but there are associated life-threatening co-morbidities, which, given the large numbers of people with DD, translates into a considerable number of deaths per annum.Despite this public health burden, relatively little seems to be known about either the mechanisms of development or causality.In the 1970s, a model of DD formulated the concept that diverticula occur as a consequence of pressureinduced damage to the colon wall amongst those with a low intake of dietary fiber.In this review, we have examined the evidence regarding the influence of ageing, diet, inflammation and genetics on DD development.We argue that the evidence supporting the barotrauma hypothesis is largely anecdotal.We have also identified several gaps in the knowledge base which need to be filled before we can complete a model for the etiology of diverticular disease.

hOGG1 Ser326Cys polymorphism modifies the significance of the environmental risk factor for colon cancer

AIM:To determine the association of hOGG1 (8-oxoguanine glycosylase I,OGG1) polymorphism of Ser326Cys substitution with colon cancer risk and possible interaction with known environmental risk factors. METHODS:A case-control study with 125 colon cancer cases and 247 controls was conducted, RESULTS:There was no major difference in Ser326Cys genotype distribution between cases and controls.The meat intake tended to increase the odds ratio for colon cancer with an OR of 1.72 (95 % confidence interval;CI=1.12-2.76). Such tendency was more prominent in Cys/Cys carriers (OR=4.31,95 % CI=1.64-11.48),but meat intake was not a significant risk factor for colon cancer in Ser/Ser or Ser/ Cys carriers.The OR for colon cancer was elevated with marginal significance in smokers who were Cys/Cys carriers (OR=2.75,95 % CI=1.07-7.53) but not in Ser/Ser or Ser/ Cys carriers. CONCLUSION:These results suggest that the hOGG1 Ser326Cys polymorphism is probably not a major contributor to individual colon cancer susceptibility overall,but the Cys/ Cys genotype may alter the impact of some environmental factors on colon cancer development.

Identification of differentially expressed genes in normal mucosa,adenoma and adenocarcinoma of colon by SSH

AIM: To construct subtracted cDNA libraries and further identify differentially expressed genes that are related to the development of colorectal carcinoma(CRC). METHODS: Suppression subtractive hybridization(SSH) was done on cDNAs of normal mucosa, adenoma and adenocarcinoma tissues from the same patient. Three subtracted cDNA libraries were constructed and then hybridized with forward and backward subtracted probes for differential screening. Positive clones from each subtracted cDNA library were selected for sequencing and BLAST analysis. Finally, virtual Northern Blot confirmed such differential expression. RESULTS: By this way, there were about 3-4 X 10(2) clones identified in each subtracted cDNA library, in which about 85% positive clones were differentially screened. Sequencing and BLAST homology search revealed some clones containing sequences of known gene fragments and several possibly novel genes showing few or no sequence homologies with any known sequences in the database. CONCLUSION: All results confirmed the effectiveness and sensitivity of SSH. The differentially expressed genes during the development of CRC can be used to shed light on the pathogenesis of CRC and be useful genetic markers for early diagnosis and therapy.

SMARCC1 copy number variation is related to metastatic colon cancer:an investigation based on TCGA data

Objective There are no well-defined genetic indicators for distant metastatic illness in patients with colon cancer(CC).The discovery of genetic changes linked to metastatic CC might aid in the development of systemic and local therapeutic approaches.Using The Cancer Genome Atlas(TCGA),we examined the relationship between copy number variation(CNV)of SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily C member 1(SMARCC1)and distant metastatic illness in patients with CC.Methods Genetic sequencing data of all relevant CC patients and clinical features were collected from TCGA using R.There were 506 CC patients with CNV and clinical outcome data.The CNV of SMARCC1 was examined for its correlation with distant metastatic disease using the TCGA CC dataset(M1 vs.M0).After adjusting for age,sex,T stage,N stage,adjuvant chemotherapy,microsatellite instability(MSI),and surgical margin status,univariate and multivariate logistic regression analyses were performed.Results SMARCC1 CNV was linked to distant metastatic disease(P=0.012 and 0.008 in univariate and multivariate analysis,respectively);positive lymph nodes and margin status were also associated with distal metastases(all P<0.01).MSI,T stage,N stage,adjuvant treatment,sex,race,and MSI were not associated with metastases(all P>0.05).Conclusion SMARCC1 CNV is associated with distant metastatic disease in patients with CC.In individuals with CC,such genetic profiles might be utilized therapeutically to support optimal systemic treatment options against local treatments for CC,such as radiation therapy,pending additional confirmation.

NGX6对结肠癌细胞系HT-29基因表达谱的影响

背景与目的:结肠癌是最常见的恶性肿瘤之一,其发病机制仍未完全明了。本研究在前期工作的基础上探讨候选抑瘤基因NGX6对结肠癌细胞系HT-29基因表达谱的影响。方法:通过脂质体介导的基因转染构建稳定表达NGX6的结肠癌细胞系pcDNA3.1(+)/NGX6/HT-29,以NGX6转染组为实验组,空白质粒转染组为对照组,利用高通量的表达谱芯片BiostarH-80sx1筛选差异表达基因,RT-PCR验证部分基因芯片的实验结果。结果:NGX6基因转染结肠癌细胞系HT-29后引起该细胞系基因表达谱广泛地改变,其中表达差异3倍以上的基因共377个,这些差异表达基因的功能涉及多个方面,包括细胞信号转导﹑细胞周期调控﹑细胞凋亡﹑细胞骨架和运动﹑基因转录和翻译、DNA损伤修复﹑蛋白质合成和代谢等。其中包括一些非常重要的信号转导通路上的分子改变,如Wnt/β-catenin信号通路上的DKK1、ILK、MMP1、COL11A1,ILK信号通路上的ILK,Eph-Ephrins信号通路上的EpHB2,RhoA信号通路上的ROCK2,RanGTPase信号通路上的RANBP1,以及RB/RBBP1信号通路上的RBBP1等。结论:NGX6转染引起了一些非常重要的信号转导通路上的分子改变,可能通过参与调节这些信号转导通路而发挥其抗肿瘤增殖和转移的作用。

磷脂酰肌醇-3-羟基激酶抑制剂LY294002对肝细胞生长因子促人结肠癌细胞SW620增殖和迁移行为的影响

目的探讨磷脂酰肌醇-3-羟基激酶(PI3K)抑制剂LYZ94002在肝细胞生长因子(HGF)促进结肠癌细胞SW620增殖、侵袭中所起的作用。方法分别用噻唑蓝比色法(MTT)、流式细胞术及划痕实验检测结肠癌细胞增殖、细胞周期、凋亡及移行情况。结果 (1)MTT法结果显示,LY294002≥20μmol/L实验组与对照组吸光度(OD)值比较,差异有统计学意义(P<0.05)。(2)流式细胞术结果显示,LY294002≥20μmol/L实验组与对照组凋亡率及增殖指数比较,差异有统计学意义(P<0.05)。(3)划痕实验结果显示,LY294002≥40μmol/L实验组与对照组移行距离比较,差异有统计学意义(P<0.05)。结论 PI3K信号通路抑制剂能够阻断HGF对人结肠癌细胞增殖、凋亡、移行的促进作用。

利用近似贝氏计算推论台湾海峡沿岸秋茄种群的拓殖路线

由于地理关系,台湾海峡两岸的红树植物组成具有高度的相似性,都以耐寒性较强的秋茄为优势种。中国台湾(以下简称"台湾")与大陆仅一水之隔,因此台湾的秋茄种群来源最有可能来自东南沿海种群,然而台湾南、北红树植物种群的拓殖路线以及与大陆东南沿海种群的遗传关系的研究至今仍未见报道。通过SSR分子标记,利用近似贝氏计算(Approximate Bayesian Computation)推测海峡两岸4个分布区域秋茄的起源及其拓殖路线。结果表明4个区域的种群出现明显分化,大陆东南北部种群与其他种群间分化程度最高。通过推测台湾北部种群起源可追溯到29000—48400a前,早于末次冰期时间,且台湾北部种群遗传结构与大陆东南南部种群最相近,推测它们可能共同起源于南方祖先。大陆东南沿海南北种群的溯祖时间约为15.1万年至25.2a年前,约为更新世中期末,则意味东南沿海南、北种群的遗传分化可能受到更新世后期气候变化与海侵海退的影响而出现隔离,或东南沿海南、北种群可能来自不同的起源。而台湾南部种群与台湾北部种群的相似性,表明台湾南部种群是由北部种群拓殖而来,近似贝氏计算亦支持这个假说。因而,可以推测海峡两岸秋茄的拓殖路线是从大陆东南南方种群随黑潮迁移至台湾北部,再从北部拓殖到台湾南部。利用近似贝氏计算推论台湾海峡两岸红树林种群起源及拓殖路线,为未来我国东南沿海红树林植物的生物地理研究提供参考。

GFP标记短小芽孢杆菌LYMC-3在马尾松体内的定殖

为研究松材线虫拮抗细菌短小芽孢杆菌LYMC-3的内生性及其在马尾松体内的定殖规律,采用扫描电子显微镜(SEM)观察菌株在马尾松组培苗体内的定殖,并采用高渗透法将质粒pGFP78转入菌株LYMC-3,对其进行绿色荧光蛋白(GFP)标记,同时测定标记菌株的遗传稳定性。在此基础上,以GFP标记和抗性标记作为示踪手段,将标记菌株接种到2年生马尾松盆栽实生苗的根部,借助激光扫描共聚焦显微镜(LSCM)和稀释涂板的方法,对马尾松根部、茎部的标记菌株进行定期回收检测。结果显示,通过SEM成功观察到菌株LYMC-3在马尾松体内的定殖,并成功获得LYMC-3菌株荧光表达强烈且遗传稳定的转化子,经过连续8次的稀释培养,其遗传稳定性为96.8%。GFP标记菌株在接种马尾松根部后的第4天,根部、茎部都能回收到大量标记菌株的存在,随后呈持续下降的趋势,且根部的下降速度快于茎部。接种40d后,根部回收标记菌株数量为0.3×102cfu/g,茎部回收标记菌株数量为0.8×102cfu/g。以上结果表明短小芽孢杆菌LYMC-3具有内生性,能在马尾松体内良好地定殖和传导。

重组荧光假单胞菌BioP8在环境中消长动态与安全性评价

通过选择分离培养和 PCR鉴定 ,对转苏云金芽孢杆菌(Bacillus thuringiensis,Bt)杀虫蛋白基因荧光假单胞菌 Bio P8及其天然受体菌 P30 3在温室自然土壤和田间大白菜根际、叶面的环境生存竞争能力进行研究。结果表明 ,在温室自然土壤中 ,可培养细菌总量在 1 0 8CFU/g土 (湿重 )左右 ,40 d内 P30 3和 Bio P8群落总量分别能维持在 1 0 5CFU /g土 (湿重 )和 1 0 4 CFU /g土 (湿重 )左右 ,1 0 0 d后检测不到残留 ;在大白菜根际 ,可培养细菌总量在 1 0 1 0 CFU/g根 (湿重 )左右 ,30 d内 P30 3和 Bio P8可维持在 1 0 6 CF U/g根 (湿重 )和 1 0 5CFU /g根 (湿重 ) ,75 d后检测不到残留 ;在大白菜叶面 ,可培养细菌总量在 1 0 3～ 1 0 6 CFU/cm2叶片之间波动 ,处理后 3d的供试菌菌量迅速由 1 0 5CFU/cm2叶片降至最低 (1 0 3CFU/cm2叶片和 1 0 2 CFU/cm2叶片左右 ) ,之后回升并以 (1 0 4和 1 0 3) CF U/cm2叶片维持一段时间 (第 5— 1 5 d) ,30 d检测不到残留。P30 3及其工程菌株在温室自然土壤、田间大白菜根际和叶面的定殖时间至少分别为 6 0 d、5 0 d和1 5 d,它们的消长动态相似 ,在温室自然土壤、田间大白菜根际的定殖能力明显强于叶面 ,Bio P8定殖能力弱于出发菌 P30

结肠癌Colo205细胞系SP细胞分子标志的初步观察

目的:寻找结肠癌Colo205细胞株中SP(side population)亚群细胞的特异性分子标志。方法:结肠癌Colo205细胞经Hoechest33342染色处理后固定,后续PI复染对其中的SP细胞进行定位,并通过荧光免疫细胞化学染色比较SP细胞与非SP细胞在DNA-PKcs、p16、FHIT、NF-κB/p65及Id2中表达的异同。结果:结肠癌Colo205细胞中Ho-echst33342低染的SP细胞比例的均数为7%;结肠癌Colo205 SP细胞的胞核体积较大,呈圆形或椭圆形,符合干细胞的形态学特点;SP细胞DNA-PKcs表达定位于整个胞核,而非SP细胞定位于核膜及其邻近核质。SP细胞DNA-PKcs表达的阳性强度明显高于非SP细胞;SP细胞Id2表达的阳性强度明显高于非SP细胞;SP细胞的p16表达的阳性强度明显低于非SP细胞;SP细胞FHIT的表达为阴性或微弱阳性;SP细胞NFκB/p65表达的阳性强度明显低于非SP细胞。结论:DNA-PKcs和Id2可能为结肠癌Colo205细胞中SP细胞的阳性分子标志,而p16、NF-κB/p65和FHIT可能为结肠癌SP细胞的阴性分子标志。

印度洋-西太平洋海洋动物谱系地理演化格局

印度洋和西太平洋海域,拥有大量浅海大陆架、边缘海和岛屿,孕育了全球最丰富的初级生产力和渔业资源,尤其是作为该区域陆源物质输入、两大洋能量汇聚中心和生物多样性中心的东印度三角,在全球海洋生物分布和进化中扮演了重要角色。本文结合物理海洋和化学海洋环境,通过线粒体基因和核基因等分子标记研究结果,归纳分析了印度洋和西太平洋区域海洋动物谱系生物地理演化格局及其可能的成因。具体结果如下:(1)雷州半岛-海南岛、冰期暴露的台湾海峡和长江冲淡水等沿岸海区,阻碍了海洋动物在海区间的扩散,南海、东海和黄、渤海广布类群,多由一个星状辐射谱系组成,种群经历最近的数量扩张和区域扩散,而仅分布于南海的物种,一般具有多个深度分歧的遗传谱系,种群呈现出数量平衡状态,同一广布物种的南海和东海种群,因区域海洋环境差异,种群数量动态演化历史不同;(2)黑潮影响区的沿岸广布类群,黑潮海流促进了顺流扩散、限制了跨海流基因交流;(3)东印度三角区,存在"华莱士线"、"赫胥黎线"和"印度洋-太平洋线"等生物地理边界,该区域海洋或咸淡水溯河洄游动物多呈现为分布在生物地理边界两侧的2个遗传谱系;(4)西太平洋,存在与目前东西向大洋环流垂直的南北向跨赤道扩散和基因流现象,可能受到目前南北向随季节反转的沿岸流和深层海流影响;(5)印度洋东西海岸共享物种,受印度洋西向赤道流影响,海洋动物多由东印度洋向西印度洋跨洋扩散;(6)西印度洋广布物种/类群,呈现了两种不同种群分化格局——遗传同质均一种群和深度分化的遗传谱系;(7)东、北印度洋和南海区域共享大量物种,可能是海盆间双向扩散的结果;(8)海洋生物谱系生物地理进化史信息,可以用于地质事件、海洋环流和古气候重建。

REV3基因对结肠癌细胞遗传信息表达的影响

利用RNA干扰技术降低REV3基因在人类结肠癌细胞(SW480)中的表达,以荧光实时定量PCR检测REV3表达量的降低情况,选择低表达效率具有统计学意义的细胞作为实验组细胞。运用细胞生长曲线、MTT、微核和姐妹染色单体交换等方法,对实验组和对照组细胞进行细胞生长周期、增殖变化情况和遗传信息表达等指标的检测。结果显示:REV3低表达的结肠癌实验组细胞在细胞增殖以及细胞的微核和姐妹染色单体交换等遗传信息表达均明显低于结肠癌对照组细胞,实验结果具有统计学意义(P<0.05);结肠癌的两对照组间(阴性和空白)的结果虽然有一定的差异,但没有统计学意义。研究结果提示,REV3低表达时,可能对结肠癌细胞(SW480)的生长与增殖产生影响,并对微核和姐妹染色单体交换等遗传不稳定现象的产生有一定的抑制作用。

DNA修复基因XRCC3多态性与结肠癌易感性的关系

目的研究DNA修复基因XRCC3多态性及其与结肠癌易感性的关系。方法选择80例经病理证实的结肠癌患者为肿瘤组,80例同期经门诊肠镜检查无异常的健康体检者为对照组,采用限制性片段长度多态性-聚合酶链反应(RFLP-PCR)法检测XRCC3基因C18607T的多态性分布,比较不同基因型与结肠癌易感性的关系。结果 XRCC3C18607T基因型C/C(野生型纯合子)、C/T(杂合子)和T/T(突变型纯合子)在肿瘤组的分布频率为58.75%、38.75%、2.50%,在对照组的分布频率为76.25%、22.50%、1.25%。各基因型在肿瘤组和对照组中的分布频率符合Hardy-Wein-berg平衡规律。与携带C/C的个体相比,携带T等位基因的变异基因型(C/T+T/T)的个体具有更高的结肠癌易感性。结论 XRCC3基因C18607T的多态性可能与结肠癌易感性相关。

重组质粒pEGFP-N3-APC在结肠癌细胞株HT-29中的表达

【目的】构建含有APC蛋白功能区域的pEGFP-N3-APC重组质粒,转染结肠癌细胞HT-29,观察重组质粒的表达。【方法】设计引物分别扩增5条APC基因功能区域片段。将扩增片段与pEGFP-N3载体连接后挑取阳性克隆,行菌落PCR和测序鉴定。使用Lipofectamine 2000将重组质粒转染结肠癌细胞株HT-29,观察细胞中绿色荧光蛋白的表达。【结果】构建5条带有APC不同结构域重组真核表达载体pEGFP-N3-APC,重组真核表达载体转染HT-29细胞后,可观察到绿色荧光蛋白的表达。【结论】真核细胞表达载体pEGFP-N3-APC的成功构建,为进一步研究其在细胞内的功能提供了基础。

热化疗对转CD基因结肠癌细胞SW480的杀伤作用

目的 探讨 5 -氟胞嘧啶 ( 5 FC )热化疗对转染组织特异性胞嘧啶脱氨基酶 (CD )基因的大肠癌细胞SW 480的作用。方法 采用脂质体法将CEA基因顺式转录调控序列 (TRS )驱动CD基因的组织特异性逆转录病毒载体G 1CEACDNa转导入大肠癌细胞SW 480 ,以G 418筛选阳性克隆扩增后 ,采用水浴加温法 ,43℃作用 3 0min共 3次 ,同时给予 5 FC进行敏感试验 ;RT PCR法检测目的基因在靶细胞的表达。结果 SW 480 CEACD细胞在 43℃作用 3 0min共 3次条件下 ,CD基因能稳定表达 ;热疗本身对SW 480细胞有一定的杀伤作用 ( P <0 .0 5 ) ,转CD基因后 ,SW 480细胞对 5 FC的敏感性明显提高 (P <0 .0 1) ,热疗与前药 5 FC合用 ,对SW 480 CEACD的杀伤作用显著大于对未转基因细胞的杀伤作用 ( P <0 .0 1) ,亦大于单独应用 5 FC时对SW 480 CEACD细胞的杀伤作用(P <0 .0 5 ) ,热化疗增加了SW 480 CEACD细胞对 5 FC的敏感性 ,并可观察到明显的旁观者效应。结论 热疗与 5 FC联合应用 ,提高了CEA组织特异性CD /5 FC系统对结肠癌细胞SW 480的靶向性杀伤作用。

大肠腺瘤与大肠癌细胞核DNA的含量

目的 检测细胞核 DNA含量在大肠癌、大肠腺瘤及正常肠粘膜中的表达 ,探讨其在大肠癌恶性转化中的意义。 方法 应用 Feulgen染色及图像分析技术分别对 5 3例结肠癌及直肠癌、30例大肠腺瘤、10例正常肠粘膜进行 DNA含量分析。 结果 正常肠粘膜、腺瘤、腺癌三组 DNA含量差别有统计学意义 (P<0 .0 5 )。将检测结果行正常组织与癌组织、腺瘤与腺癌、腺瘤与正常组织之间做两两比较 ,除腺瘤与正常组织之间外 ,其他各组都有显著性差别。 结论 DNA含量测定对早期发现大肠腺癌有重要意义 ,为判断大肠疾病的性质提供细胞生物学依据。