Role of the cGAS-STING pathway in regulating the tumor-immune microenvironment in dMMR/MSI colorectal cancer.
Cancer Immunol Immunother
; 71(11): 2765-2776, 2022 Nov.
Article
in En
| MEDLINE
| ID: mdl-35429245
ABSTRACT
Deficient mismatch repair (dMMR)/microsatellite instability (MSI) colorectal cancer (CRC) has high immunogenicity and better prognosis compared with proficient MMR (pMMR)/microsatellite stable (MSS) CRC. Although the activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway has been considered to contribute to the high number of CD8+ TILs, its role in dMMR/MSI CRC is largely unknown. In this study, to examine the role of the cGAS-STING pathway on the recruitment of CD8+ TILs in dMMR/MSI CRC, we used public datasets and clinical tissue samples in our cohorts to evaluate the expression of cGAS, STING, and CD8+ TILs in pMMR/MSS and dMMR/MSI CRCs. According to the analysis of public datasets, the expression of cGAS-STING, CD8 effector gene signature, and CXCL10-CCL5, chemoattractants for CD8+ TILs which regulated by the cGAS-STING pathway, was significantly upregulated in dMMR/MSI CRC, and the expression of cGAS-STING was significantly associated with the expression of CD8 effector gene signature. Immunohistochemistry staining of the clinical tissue samples (n = 283) revealed that cGAS-STING was highly expressed in tumor cells of dMMR CRC, and higher expression of cGAS-STING in tumor cells was significantly associated with the increased number of CD8+ TILs. Moreover, we demonstrated that the downregulation of MMR gene in human CRC cell lines enhanced the activation of the cGAS-STING pathway. Taken together, for the first time, we found that dMMR/MSI CRC has maintained a high level of cGAS-STING expression in tumor cells, which might contribute to abundant CD8+ TILs and immune-active TME.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Colorectal Neoplasms
/
DNA Mismatch Repair
Type of study:
Prognostic_studies
Limits:
Humans
Language:
En
Journal:
Cancer Immunol Immunother
Journal subject:
ALERGIA E IMUNOLOGIA
/
NEOPLASIAS
/
TERAPEUTICA
Year:
2022
Type:
Article
Affiliation country:
Japan