Important biological features such as tumor metastasis patterns in advanced metastatic colorectal cancer

Colorectal cancer has the third highest incidence of all cancers in the world, and the second highest death toll

In recent years, high-throughput sequencing technology has been widely used to study the pathogenesis and molecular mechanism of colorectal cancer

On August 16, 2022, the research group of Tang Fuqiu from the Biomedical Frontier Innovation Center of Peking University (BIOPIC) and the research group of Fu Wei from the General Surgery Department of Peking University Third Hospital jointly published a paper entitled "Single-cell Genomic and Transcriptomic Landscapes of Primary and Metastatic Colorectal CancerTumors" research paper

In this study, the surgical resection samples of 11 patients with metastatic colorectal cancer were obtained using a multi-point sampling strategy to obtain primary tumor tissue, lymph node metastasis tumor tissue, liver metastasis tumor tissue, and omentum metastasis tumor tissue.

This study not only systematically analyzed the dynamic changes of different cell types and tumor subclonal composition, gene expression, signaling pathways, genome copy number variation and somatic mutations during the development and metastasis of colorectal cancer, but also studied at the single-cell level.

Figure 1 Flow chart of sampling of colorectal cancer tumor samples

The study has the following key findings:

1.

Figure 2A.

To further validate the differentiation potential of SOX9+MKI67+ double-positive cells, we performed high-precision single-cell transcriptome sequencing analysis of five organoid spheroids from one patient

Figure 3A.

2.

Figure 4A.

3.

Figure 5A.

Fig.

4.
It was found that EKC/KEOPS complex may promote the metastasis of colorectal cancer cells with TP53 mutation
.
By simultaneously performing single-cell transcriptome sequencing and cDNA Sanger sequencing of specific driver gene mutations on single cells, this study analyzed the relationship between driver gene mutations and gene expression signatures at the single-cell level in tumor tissues from colorectal cancer patients
.
TP53 mutation is one of the most common gene mutations in colorectal cancer patients.
The study carried out tumor subclonal analysis and tumor metastasis pattern reconstruction in two patients with TP53 gene mutation, and found that TP53RK and TPRKB in the EKC/KEOPS complex The high expression of the gene may promote the metastasis of tumor cells with TP53 mutation
.
Previous studies have shown in vitro experiments in tumor cell lines that the loss of TPRKB expression results in the growth inhibition of TP53 mutant cells, while the tumor cells of TP53 wild-type are almost unaffected by the loss of TPRKB expression, indicating that TPRKB plays an important role in the regulation of TP53 mutant cells.
role
.
This study is the first to verify the potential role of the EKC/KEOPS complex on tumor metastasis between tumor subclones with the same genetic background in patients, effectively excluding in vitro cultured cell lines and comparisons between different patients due to genetic backgrounds Differences may cause experimental error
.

Figure 7 Experimental flow chart of single-cell cDNA Sanger sequencing and single-cell RNA-seq combined sequencing

Figure 8A.
tSNE cluster map of patient number four
.
The color of the cells represents the sampling location, mitochondrial mutation, CNV variant subclone type, and the average expression of specific highly expressed genes in OLFM4+SOX9+ double-positive cells relative to OLFM4+ single-positive cells
.
B.
Heat map showing the expression of differentially expressed genes in OLFM4+SOX9+ double-positive cells and OLFM4+ single-positive cells in different cell types of patient No.
4
.
C.
tSNE cluster diagram showing the expression of TPRKB, TP53RK and IDH1 genes in the epithelial cells of patient No.
4

In summary, this study explored the transformation of tumor cell types and the changes of key signaling pathways during the occurrence and development of colorectal cancer through a single-cell multi-omics study of patients with advanced metastatic colorectal cancer.
The organ culture system was systematically validated
.
At the same time, the in vitro organoid culture system provides a potential drug efficacy testing strategy for the treatment of colorectal cancer
.
In addition, this study deeply studied the subclonal composition of primary tumors and different metastatic tumors in the same patient, and reconstructed the relationship of tumor metastasis on this basis, and explored the driver gene mutation and gene expression at the single-cell level.
and the important role of driver gene mutations in tumor metastasis
.

Dr.
Wang Rui, Dr.
Li Jingyun, Dr.
Mao Yunuo from Peking University Biomedical Frontier Innovation Center (BIOPIC), Associate Researcher Zhou Xin and Dr.
Wang Wendong from Peking University Third Hospital, and researcher Gao Shuai from China Agricultural University tied for the first place in the paper The authors, Professor Tang Fuchou from Peking University Biomedical Frontier Innovation Center and Professor Fu Wei from Peking University Third Hospital are the co-corresponding authors of the paper
.
This project was funded by the National Natural Science Foundation of China, and supported by the Center for Life Instrumentation (Imaging Platform) of Peking University and the Center for High-throughput Sequencing of Peking University
.