最近在朋友圈看到了12月14日发表在Cell 杂志的文章:《Differential pre-malignant programs and microenvironment chart distinct paths to malignancy in human colorectal polyps》,研究团队对患者同一息肉样本完成scRNA-seq、外显子组(Exome-seq)、多重免疫荧光(MxIF)及多重免疫组化(MxIHC)分析。
其中 scRNA-seq、外显子组(Exome-seq) 是我们的老朋友了,已经有成系统的大量的教程,关于它们的数据处理。但是多重免疫荧光(MxIF)及多重免疫组化(MxIHC)目前太小众,先略过。
该研究涉及到的样品及数据情况,如下所示:
分成两个队列:
- The discovery (DIS) set consisted of 65 specimens analyzed including 30 tumors.
- The validation (VAL) set consisted of 63 specimens analyzed including 32 tumors
取样材料Polyps的分类是: - NL 就是 正常样品啦
- ADs consisting of tubular ADs (TAs) and tubulovillous ADs (TVAs),
- serrated polyps (SERs) consisting of hyperplastic polyps (HPs) and SSLs
- HPs were further subdivided into goblet cell-rich HPs (GCHPs) and microvesicular HPs (MVHPs), with MVHPs appearing more advanced and may prog- ress to SSLs
这些全部的Polyps样品都有自己的突变,可以展现突变全景图。但是我们这里更关心单细胞方面,是 128 independent scRNA-seq datasets on 62 tumors were generated, 有 142,065个细胞,其中
- HPs were further subdivided into goblet cell-rich HPs (GCHPs) and microvesicular HPs (MVHPs), with MVHPs appearing more advanced and may prog- ress to SSLs
- 70,691 (DIS dataset)
- 71,374 cells (VAL dataset)
在两个单细胞数据集都可以看到比较清晰的降维聚类分群结果 :
癌症细胞主要是: - ASC – adenoma specific cells,
- SSC – serrated specific cells
其中normal epithelial cells包括: - 吸收细胞(ABS,absorptive cell)
- 隐窝顶部结肠细胞(CT,crypt top colonocytes)
- 内分泌细胞(EE enteroendocfine cells)
- 杯状细胞 (GOB,goblet cells)
- 干细胞(STM,stem cells)
- 过渡放大细胞(TAC,transit amplifing cells)
- 肠道簇细胞(TUF,tuft cells)
这9个亚群都有各自标记基因,热图展现如下所示:
可以很清晰的看到: - ASCs resembled colonic stem and progenitor cells, expressed genes indicative of WNT pathway activation (LGR5, OLFM4, ASCL2, AXIN2, RNF43, and EPHB2)
- SSCs highly expressed genes not normally observed in the colon (MUC5AC, AQP5, TACSTD2 [TROP2], TFF2, MUC17, and MSLN)
而7种肠道正常上皮细胞亚群各自的基因在热图里面很少,很容易背诵。
恰好我看到了一个数据集,是 Tissue of 12 patients was collected from tumor areas and adjacent normal tissue after surgical removal of the tumor. 以前处理过这个 2021-GSE166555_12个CRC病人的N-T配对-10x 单细胞数据集,可以使用它来检查一下这个文章里面的7种肠道正常上皮细胞亚群标记基因是否有可取之处。对这个GSE166555进行降维聚类分群后如下所示,被我挑选的是上皮细胞:
这个时候需要使用识图软件或者网页工具,在前面的热图里面把全部的基因名字拿到,或者人工整理。然后在这个GSE166555数据集里面进行可视化,感兴趣的小伙伴可以自己测试看看,这里略关于 结肠图谱计划(COLON Map)
首先需要了解癌前图谱PreCancer atlas(PCA)计划。
范德堡大学细胞生物学教授Robert Coffey, 系统生物学家Ken Lau博士以及肿瘤流行病学家Martha Shrubsole博士发起结肠图谱计划(COLON Map),隶属PCA计划的一部分。