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were routinely fed and given ordinary drinking water for 32 weeks,and those in model group were routinely fed and received water
containing 0.1 mg/ml cancer inducer 4-nitroquinoline-1-oxide for 16 weeks,and then only fed with ordinary drinking water for
another 16 weeks. Stool samples of both groups were collected,and DNA in faeces was extracted and amplified by PCR,followed
by high-throughput sequencing. The obtained sequencing data were divided into operational taxonomic units (OTU) based
on the similarity between sequences. The α-diversity,β-diversity and species abundance were further analyzed according
to species annotation. Results No death occurred in the experiment,and the modeling of ESCC was successfully established
in model group. Compared with control group,the proportion of Bacteroidota and Firmicutes increased,while the proportion
of Verrucomicrobiota and Proteobacteria decreased in model group. Analysis showed that the α-diversity measured by Shannon
Diversity Index in model group was lower than that of control group (P<0.05). As for β-diversity analysis,PCoA diagram
showed that the gut floras of control and model groups clustered in different quadrants,suggesting a significant discrepancy
between the groups(t=22.444,P=0.004). At the phylum level,the abundances of unidentified bacteria,Cyanobacteria,
Elusimicrobia and Campilobacterota were higher in model group than those in control group (P<0.05). At the genus level,the
abundances of Prevotellaceae_UCG-003,Bacteroides and Lachnospiraceae_NK4A136_group,Ruminococcus,Prevotellaceae_
UCG-001,Prevotella,Colidextribacter,Lachnospiraceae_UCG-006 were higher while those of Romboutsia and Turicibacter
were lower in model group than those in control group (P<0.05). LEfSe analysis showed that,at the genus level,the
abundances of Prevotellaceae_UCG-003,Escherichia-Shigella,Bacteroides,Lachnospiraceae_NK4A136_group were increased
significantly in model group (P<0.05),but the abundance of Romboutsia was increased significantly in control group DZ(P<0.05).
Conclusion By comparing the composition of gut flora,we identified the rat model of ESCC may have less diversity of species
and specially differentiated bacteria,and Prevotellaceae_UCG-003,Bacteroides,Lachnospiraceae_NK4A136_group,and
Romboutsia could be used as biomarkers for ESCC.
【Key words】 Esophageal squamous cell carcinoma;Esophageal neoplasms;Gastrointestinal microbiome;Intestinal
flora;Mice;Biodiversity
最新的《全球癌症统计报告》数据显示,2020 年
本研究背景:
全球食管癌新发病例数为 60.4 万例,死亡病例数为
已有研究表明肠道菌群与多种肿瘤的发生、发展
54.4 万例,分别占全球癌症新发、死亡总病例数的 3.1%、 和治疗密切相关,尤其在结直肠癌、肝癌方面的研究
5.5% [1] 。食管癌发病风险地域差异较大,我国是食管
较多。食管癌是我国的高发肿瘤,其发病率与死亡率
癌发病高风险国家,据统计 2020 年我国新发食管癌病
均为世界平均水平的 2 倍以上。我国以食管鳞癌为主,
例数为 32.4 万例,死亡病例数为 30.1 万例,分别占全 早期行根治术后预后较好,但相当多的患者就诊时已
球食管癌新发、死亡总病例数的 53.7%、55.3% [2] 。我
处于中晚期,失去手术机会。因此寻找简便易取材的
国食管癌患者病理类型以鳞癌为主,早期行根治术后预
检验方法,提高食管癌早期诊断率并给予干预措施十
后较好,但由于相当多的食管癌患者确诊时已处于中晚
分重要。
期,失去了手术机会,因此提高食管癌早期诊断率仍具
本研究创新点:
有十分重要的意义。
(1)高比例成功制备了食管鳞癌原位模型小鼠,
随着高通量测序技术的应用与发展,肠道微生态研
模拟了食管鳞癌发生、发展的过程,为同类研究提供
究已成为目前肿瘤领域研究的热点之一。有研究证实肠
了基础。(2)选择饲养环境一致的小鼠作为研究对象,
道菌群在肿瘤的发生、发展中具有重要作用,食管鳞癌
可以减少因为饮食、环境等因素对菌群研究结果造成
患者口腔、癌组织及癌旁正常组织中菌群结构发生了改
变并与食管癌的发生有关 [3-4] 。因肠道菌群的影响因素 的误差。(3)通过初步对食管癌差异菌属的筛选,
为下一步探讨机制研究提供基础。
较多,本研究特选取饲养环境可控的食管鳞癌原位模型
小鼠,以观察与食管鳞癌相关的肠道菌群结构变化、筛 遵照河北医科大学实验动物中心指南执行,遵守动物保
选出特异性改变的肠道菌属,为食管鳞癌的早期筛查提 护、动物伦理原则及相关规定。本实验时间为 2020 年
供参考。 8 月至 2021 年 5 月。
1 材料与方法 1.2 干预方法 DZ 组小鼠常规喂养 32 周,全程给予
1.1 实验动物 从北京维通利华实验动物技术有限公 普通饮用水;MX 组小鼠按照造模方法常规喂养并给予
司购买雌性 SPF 级 C57BL/6 小鼠 20 只〔合格证号: 含 0.1 mg/ml 的诱癌剂 4- 硝基喹啉 -1- 氧化物(4NQO)
SCXK(京)2016-0006〕,体质量 14~17 g,鼠龄 6 周。 饮用水喂养 16 周,之后给予普通饮用水喂养至 32 周。
适应性喂养 1 周后将所有小鼠随机分为对照组(DZ 组) 4NQO 饮用水制备方法:将诱癌剂 4NQO(购自 Sigma-
和模型组(MX 组),每组 10 只。所有实验操作严格 Aldrich 公司,型号:N8141)溶解于 1,2 丙二醇,配