Elevated expression of protein-L-isoaspartate O-methyltransferase-1 (PCMT1) in cervical cancer

Protein-L-isoaspartate O-methyltransferase-1 (PCMT1) is a protein carboxyl methyltransferase enzyme, which has been found to play roles in cancers. However, no clinical information about the correlation between cervical cancer and PCMT1 expression has been reported.

We used immunohistochemistry (IHC) to characterize the protein level of PCMT1 in human cervical intraepithelial neoplasia and cervical cancer specimens. The mRNA expression profile of PCMT1 in cervical cancer was also analyzed by using Gene Expression Omnibus (GEO) databases. The prognostic value of PCMT1 in patients with cervical cancer was evaluated by using the Kaplan-Meier plotter. Gene set enrichment analysis (GSEA) was conducted by using The Cancer Genome Atlas (TCGA) cervical cancer dataset.

The protein level of PCMT1 was increased in cervical high-grade squamous intraepithelial lesion (HSIL) (7.40±0.42) and cervical cancer tissues (10.70±0.54), compared to normal cervix (5.00±0.86) and low-grade squamous intraepithelial lesion (LSIL) (6.22±0.57) (P<0.05). the immunoreactivity score (IRS) of PCMT1 was also higher in cervical cancer tissues than in paired adjacent non-cancerous cervical tissues (9.03±0.52 vs. 6.32±0.46) (P<0.05). High expression of PCMT1 was associated with decreased overall survival (OS) of patients with cervical cancer (P=0.0022). GSEA demonstrated that cervical cancer patients with high expression of PCMT1 were enriched in the various cancer-related signaling pathways.

These results suggest that PCMT1 might be a diagnostic and prognostic biomarker for cervical cancer, and further validation studies should be performed.