[Expression of keratin 1/sialyl-Tn antigen in primary and metastatic cervical squamous cell carcinomas]

Objective: To investigate the expression of keratin 1 (KRT1) and sialyl-Tn antigen (sTn) in cervical squamous cell carcinoma and its possible mechanism. Methods: Six cervical squamous cell carcinoma specimens were collected at the First Affiliated Hospital of Soochow University, Suzhou, China from 2022 to 2023. Spatial transcriptomics analysis was performed on the paraffin sections of 6 patients to analyze the transcriptomes of invasive squamous cell carcinoma and adjacent normal cervical squamous epithelium. The differential gene KRT1 was selected. Kaplan-Meier survival analysis was used to examine the prognostic value of KRT1 in cervical squamous cell carcinoma patients using the TCGA database. The possible downstream molecule sTn was identified according to literature research. Immunohistochemistry was carried out to investigate the expression of KRT1 and sTn proteins in the primary tumor and metastases of cervical squamous cell carcinoma (40 cases with pelvic lymph node metastasis and 30 cases without). Spearman correlation analysis was conducted to analyze the correlation of their expression. Results: The spatial transcriptomic results of the 6 specimens indicated that the level of KRT1 mRNA significantly decreased in cervical squamous cell carcinoma (compared with that in adjacent normal cervical squamous epithelium), while Kaplan-Meier survival analysis revealed that cervical squamous cell carcinoma patients with low KRT1 mRNA levels (versus high) had a worse prognosis. Immunohistochemistry proved that KRT1 expression was significantly lower in cervical squamous cell carcinoma than in adjacent normal squamous epithelium (P<0.05), but sTn showed the opposite change (increased in carcinoma, P<0.05). The expression changes of KRT1 and sTn were inversely correlated (r=-0.217, P<0.05). In addition, the expression levels of KRT1 and sTn in lymph node metastases were not significantly different from those in primary tumors. Conclusions: The decreased expression of KRT1 in primary cervical squamous cell carcinoma and lymph node metastasis may promote tumor cell proliferation and inhibit apoptosis by upregulating sTn, contributing to the poor prognosis of advanced cervical squamous cell carcinoma.