Single-cell transcriptomics and deep tissue proteomics reveal distinct tumour microenvironment present in stage-I and II cervical cancer

Abstract Background Cervical cancer (CC) is the 3rd most common cancer in women and the 4th leading cause of deaths in gynaecological malignancies, yet the exact progression of CC is inconclusive, mainly due to the high complexity the changing tumour microenvironment (TME) at different stages of tumorigenesis. Importantly, a detailed comparative single-cell transcriptomic analysis of tumour microenvironment (TME) of CC patients at different stages is lacking. Methods In this study, a total of 42,928 and 29,200 cells isolated from the tumour tissues of stage-I and II CC patients and subjected to single-cell RNA sequencing (scRNA-seq) analysis. The cell heterogeneity and functions were comparatively investigated using bioinformatic tools. In addition, label-free quantitative mass spectrometry based proteomic analysis was carried out. The proteome profiles of stage-I and II CC patients were compared, and an integrative analysis with the scRNA-seq was performed. Results Compared with the stage-I CC (CCI) patients, the immune response relevant signalling pathways were largely suppressed in various immune cells of the stage-II CC (CCII) patients, yet the signalling associated with cell and tissue development was enriched, as well as metabolism for energy production suggested by the upregulation of genes associated with mitochondria. This was consistent with the quantitative proteomic analysis that showed dominance of proteins promoting cell growth and intercellular matrix development in the TME of CCII group. The interferon-α and γ response appeared the most activated pathways in many cell populations of the CCI patients. Several collagens, such as COL12A1, COL5A1, COL4A1 and COL4A2, were found significantly upregulated in the CCII group, suggesting their roles for diagnosing CC progression. A novel transcript AC244205.1 was detected as the most upregulated gene in CCII patients, and its possible mechanistic role CC may be investigated further. Conclusions Our study provides important resources for decoding the progression of CC and set the foundation for developing novel approaches for diagnosing CC and tackling the immunosuppressive TME.