Cancer Stem Cells Remodel the Tumor Microenvironment and Influence Immunotherapy Response in Hepatocellular Carcinoma

Abstract

Background: Cancer stem cells are the important factors that lead to drug resistance, recurrence and metastasis of tumor. Immunotherapy has become the first-line treatment for advanced Hepatocellular Carcinoma(HCC), however, the importance of cancer stem cells in the immunotherapy of HCC has not been well elucidated. Methods: We identified a subset of cells with stemness characteristics by analyzing single-cell sequencing data from tumor tissue samples from 10 patients with HCC. We screened these cell populations for overexpressed genes, defined as cancer stem cell-related genes. Subsequently, we comprehensively analyzed the bulk RNA sequencing data of 365 HCC patients to construct a cancer stem cell-related genes prognostic signature(CSGPS). According to the CSGPS, 365 patients with HCC were divided into high-risk and low-risk groups. Multiple independent external cohorts were used to assess the predictive value of the CSGPS. T cell receptor (TCR) richness, Cancer Testicular Antigens (CTA) scores, Microsatellite instability (MSI), expression of immune checkpoint-related genes, and Tumour Immune Dysfunction and Exclusion (TIDE) scores were used to assess the intensity of response to immunotherapy in different risk groups. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to verify the mRNA expression levels of cancer stem cell-related genes in HCC tissues. Results: CSGPS is an independent risk factor for the prognosis of HCC patients, and it is significantly superior to other clinical features in predicting the prognosis and immunotherapy response of HCC patients. Multiple independent external cohorts validated the validity and robustness of the CSGPS. Immune infiltration analysis showed that cancer stem cell-related genes can recruit immune cells with immunosuppressive functions, such as Treg, macrophages infiltration. The CSGPS was correlated with the TCR, CTA score, MSI score, expression of immune checkpoint-related genes, and TIDE score. Patients in the high-risk group identified by the CSGPS may respond more strongly to immunotherapy and be more suitable to immunotherapy. The results of qRT-PCR confirmed that 8 cancer stem cell-related genes were overexpressed in HCC tissues. Conclusion: Cancer stem cell-related genes are overexpressed in HCC and contribute to the formation of an immunosuppressive microenvironment. Targeting cancer stem cells may become a new target for immunotherapy of HCC. Our novel prognostic signatureof cancer stem cell-related genes can effectively predict the prognosis and immunotherapy response of HCC patients. In the future, the prognostic signature will help clinicians to select the appropriate population for immunotherapy and improve the response rate of immunotherapy.