SOX1 and PAX1 Are Hypermethylated in Cervical Adenocarcinoma and Associated with Better Prognosis

Reactivation of methylation-silenced PAX1 inhibits cervical cancer proliferation and migration via the WNT/TIMELESS pathway

Although aberrant methylation of PAX1 is closely associated with cervical cancer (CC), PAX1 methylation (PAX1m) and its role in CC remain to be elucidated. Here, we clarified the biological function of PAX1 in CC. First, PAX1m in ThinPrep cytologic test samples was measured via quantitative methylation-specific PCR. The results showed that PAX1 promoter methylation levels were significantly increased in CC patients (p < 0.001). We also found that PAX1 promoter methylation levels were positively correlated with tumor purity but negatively correlated with immune-infiltration via public databases. Then, CRISPR-based methylation perturbation tools (dCas9-Tet1) were constructed to further demonstrate that DNA methylation participates in the regulation of PAX1 expression directly. Gain- and loss-of-function experiments were used to show that PAX1 overexpression restrained proliferation, migration and improved cisplatin sensitivity by interfering with the WNT/TIMELESS axis in CC cells. Additionally, Co-immunoprecipitation assays further confirmed the interaction between PAX1 and TCF7L2. Taken together, our results suggested that a tumor suppressor role of PAX1 in CC and that CRISPR-based PAX1 demethylation editing might be a promising therapeutic strategy for CC.

PAX1 and SOX1 Gene Methylation as a Detection and Triage Method for Cervical Intraepithelial Neoplasia Diagnosis

INTRODUCTION

Methylation assays have demonstrated potential as dependable and high-precision approaches for identifying or triaging individuals with cervical cancer (CA) or cervical intraepithelial neoplasia (CIN). Our investigation aimed to assess the efficacy of the diagnosis and triage of the PAX1/SOX1 methylation panel in detecting CIN or CA.

METHODS

A total of 461 patients with abnormal high-risk human papillomavirus (hrHPV) or cytology test results were recruited for this study. Each patient underwent an assortment of assessments, comprising a cytology test, hrHPV test, colposcopy examination, and PAX1 and SOX1 methylation tests.

RESULTS

The extent of methylation of both genes demonstrates a positive correlation with the severity of CIN lesions and CA. To determine the correlation for patients with CIN2 or worse (CIN2+), the area under curve was 0.821 (95% CI: 0.782-0.853) for PAX1 and 0.800 (95% CI: 0.766-0.838) for SOX1, while for CIN3 or worse (CIN3+), 0.881 (95% CI: 0.839-0.908) for PAX1 and 0.867 (95% CI: 0.830-0.901) for SOX1. The PAX1/SOX1 methylation marker panel performed sensitivity and specificity of 77.16% and 91.67% for CIN2+, 84.76% and 90.50% for CIN3+, respectively. Regarding triaging hrHPV+ patients, the PAX1/SOX1 methylation test only referred 11.83% of the patients who are unnecessary for colonoscopy examination, which is comparatively lower than cytology, thereby signifying a promising triage strategy for hrHPV-positive women. Furthermore, we observed that the positive PAX1/SOX1 methylation test result for untreated CIN1 or fewer patients would result in a higher likelihood of progression upon a 24-month follow-up visit.

CONCLUSION

The present investigation demonstrates that the PAX1/SOX1 methylation marker panel exhibits favorable diagnostic performance in CIN detection and holds the potential to be employed for individual CIN tests or hrHPV-positive triage.

Utilization of PAX1 methylation test for cervical cancer screening of non-HPV16/18 high-risk HPV infection in women

Aim: To evaluate the clinical performance of PAX1 methylation (PAX1m) and cytology for patients with non-HPV16/18 high-risk HPV (hrHPV) infection. Methods: Cervical exfoliated cells from 387 outpatients with non-HPV16/18 hrHPV - positive were collected for cytology and PAX1m assays. Results: The PAX1m level increased with the severity of cytology and histopathology. For cervical intraepithelial neoplasia (CIN)CIN2+/CIN3+, the areas under the curve were both 0.87. The specificity and positive predictive value (PPV) of PAX1m were greater than abnormal cytology (CIN2+ specificity: 75.5 vs 24.8%; PPV: 38.8 vs 18.7%; CIN3+ specificity: 69.3 vs 22.7%; PPV: 14.0 vs 6.7%). Conclusion: PAX1m increased specificity and PPV for CIN2+/CIN3+ compared with cytology for women with non-HPV16/18 hrHPV (+).

The role of PAX1 methylation in predicting the pathological upgrade of cervical intraepithelial neoplasia before cold knife conization

Objective

To explore the ability of PAX1 methylation (PAX1^m) to predict the pathological upgrade of cervical intraepithelial neoplasia (CIN) before cold knife conization (CKC).

Methods

A total of 218 women that underwent colposcopy-directed biopsy (CDB) pathology for the confirmation of CIN2 and CIN3 between December 2020 to September 2021 were enrolled in this study. The methylation levels of PAX1 (ΔCp_PAX1) were determined by quantitative methylation-specific polymerase chain reaction (qMSP). Receiver operating characteristic curve was used to identify the optimal cut-off value of ΔCp_PAX1 for predicting the pathological upgrade of disease.

Results

In the CDB-confirmed CIN2 group, 36% of CIN2 was found to have pathologically upgraded to CIN3 and 30% regressed to low-grade squamous intraepithelial lesion (LSIL) and below, and none of CIN2 upgraded to early-stage cervical cancer (ESCC) after CKC. In the CDB-confirmed CIN3 group, 19.5% (23/118) of CDB-confirmed CIN3 were pathologically upgraded to ESCC after CKC. Regardless of CIN2 or CIN3, the ΔCp_PAX1 level of women with upgraded pathology after CKC was significantly lower than that of women with degraded pathology. The optimal △Cp_PAX1 cut-off value in predicting CIN3 to be upgraded to ESCC after CKC was 6.360 and the area under the curve (AUC) was 0.814, with similar sensitivity (78.3%) and higher specificity (84.2%) than cytology≥LSIL (Se:78.3%;Sp:58.9%) and HPV16/18 positive (Se:73.9%;Sp:46.3%) patients.

Conclusions

PAX1^m could be a promising auxiliary marker in predicting the pathological upgrade of CIN before CKC. We found that if the △Cp _PAX1 cut-off value is lower than 6.360, it is highly suggestive of invasive cervical cancer.

An overview of PAX1: Expression, function and regulation in development and diseases

Transcription factors play multifaceted roles in embryonic development and diseases. PAX1, a paired-box transcription factor, has been elucidated to play key roles in multiple tissues during embryonic development by extensive studies. Recently, an emerging role of PAX1 in cancers was clarified. Herein, we summarize the expression and functions of PAX1 in skeletal system and thymus development, as well as cancer biology and outline its cellular and molecular modes of action and the association of PAX1 mutation or dysregulation with human diseases, thus providing insights for the molecular basis of congenital diseases and cancers.