Expression of p16INK4a and human papillomavirus 16 with associated risk factors in cervical premalignant and malignant lesions

Analysis of HPV-16 viral load, integration status, and p16 expression in relation to EBV co-infection and cervical lesion severity

Cervical cancer, one of the most common cancers in women, is primarily driven by high-risk human papillomaviruses (HPV) infections, particularly HPV-16. Co-infection with Epstein-Barr virus (EBV) has been reported to exacerbate disease progression by influencing HPV genome integration. This study examines HPV-16 integration status, p16INK4a expression, and their relationship with EBV co-infection and viral load in cervical cancer cases. In this study, 134 HPV-16-positive formalin-fixed, paraffin-embedded cervical samples were collected and analyzed for HPV-16 viral load, genome integration and EBV co-infection, followed by p16INK4a immunohistochemistry. Statistical analysis was performed to examine the association between viral markers and cervical cancer progression. HPV-16 viral loads varied significantly by histological grade, with the highest loads observed in cervical intraepithelial neoplasia 2 (CIN 2) lesions. HPV integration status revealed episomal forms in 32.8% of samples, mixed forms in 56%, and fully integrated forms in 11.2%. p16INK4a expression correlated with disease progression, increasing with CIN grade and in squamous cell carcinoma (SCC). EBV was detected in 13.4% of samples, but no significant associations were found between EBV infection and HPV integration, viral load, or p16INK4a expression levels. HPV-16 viral load and integration status are strongly associated with cervical lesion severity, while p16INK4a expression increases with lesion grade, indicating its utility as a diagnostic marker. EBV co-infection did not significantly impact lesion progression, suggesting that its role in cervical cancer remains unclear.

Association between serum P16ink4A concentration and CIN and cervical cancer among women attending a cervical cancer clinic in western Uganda: A case control study

Introduction

Tissue expression of P16ink4A is correlated with cervical lesions. In this study we determined the association between serum P16ink4A concentrations and cervical lesions among women attending the cervical cancer clinic at Mbarara Regional Hospital (MRRH) South Western Uganda.

Material and Methods

We recruited 90 cervical intraepithelial neoplasia (CIN) cases, 90 cervical cancer (CC) cases before treatment and 90 controls. Clinical and demographic data were recorded. Serum P16ink4A concentrations were measured by quantitative Elisa. Cases were confirmed with cytology and/or histology. Descriptive statistics and logistic regression were done with STATA 17 and P-values of <0.05 were considered statistically significant.

Results

The mean serum P16ink4A concentration among CIN cases, CC cases and controls was 1.11(+/-0.66) ng/ml, 1.45(+/-1.11) ng/ml and 1.13(+/-0.61) ng/ml respectively (p = 0.008). 50 % of CIN cases and controls as well as 60 % of CC cases had P16ink4A concentration above 0.946 ng/ml. There were increased odds of CIN for serum P16ink4A though statistically insignificant (AOR: 1.11, p-value: 0.70). There was also a statistically significant reduction in odds of CC for serum P16ink4A (AOR: 0.55, p-value: 0.01).

Conclusion

Serum P16ink4A may likely be associated with cervical lesions especially CC in our study population and this may aid detection of such lesions. Diagnostic utility studies for circulating P16ink4A in detection of cervical cancer are recommended.

Expression analysis of p16 and TOP2A protein biomarkers in cervical cancer lesions and their correlation with clinico-histopathological characteristics in a referral hospital, Tanzania

Introduction

Biomarkers yield important information for early diagnosis of cervical cancer. However, they are rarely applied for prognosis of cervical cancer in Tanzania, where visual inspection assay with acetic acid or Lugol’s iodine and Pap test are being used as the standard screening/ diagnostic methods.

Methods

This was a retrospective hospital-based cross-sectional study that was conducted to assess cyclin-dependent kinase inhibitor (p16) and topoisomerase II-alpha (TOP2A) proteins expression among women seeking cervical cancer care at Kilimanjaro Christian Medical Centre, Tanzania between May 1, 2017 and May 10, 2018. Immunohistochemistry technique was used to detect the expressions of p16 and TOP2A proteins from the retrieved formalin-fixed and paraffin-embedded (FFPE) cervical biopsies.

Results

A total of 145 patients, with a mean age of 52.1 ± 12.9 years, were included in this study. Upon immunohistochemistry staining, 103 (71.0%) and 90 (62.1%) were p16 and TOP2A positive respectively. There was a strong association between histopathological class and p16/TOP2A expression levels (Fisher’s exact test, p<0.001). Moreover, there was a strong positive correlation between p16/TOP2A and cancerous cervical lesions (Spearman’s rank correlation coefficients = 0.833 and 0.687, p = 0.006 and 0.005, respectively). The age-adjusted odds ratio for predicting cervical cancer lesions were independently significant for p16/TOP2A biomarkers in FFPE cervical tissues [p16: OR = 1.142 (95% CI: 1.059–1.232, p<0.001) and TOP2A: OR = 1.046 (95% CI: 1.008–1.085, p = 0.015)]. Importantly, the diagnostic performance of p16 was higher than that of TOP2A in the diagnosis of cancerous lesions from non-cancerous cervical lesions (sensitivity: 97.2% versus 77.6%, accuracy: 92.8% versus 87.8%, respectively).

Conclusion

Our study has highlighted that over-expression of TOP2A is related to the grade of cervical intraepithelial neoplasia but does not predict prognosis in cervical cancer. Similarly, expression of p16 is related to degree of histological dysplasia and malignancy, suggesting its prognostic and predictive value in the management of cervical cancers. Further bigger studies are needed to validate their applications in the early diagnosis of cervical cancer.

Prevalence of high-risk human papillomavirus and cervical lesion risk factors: A population-based study in Zhejiang, China 2010-2019

This study investigates the epidemiological characteristics of high-risk human papillomavirus (hrHPV) and analyzes the risk of cervical lesions among women in Zhejiang province, China. HPV data were collected retrospectively from a cohort of 67 742 women who underwent routine cervical cancer screening from 2010 to 2019. Precancerous and cervical cancer cases (n = 980) were histologically diagnosed as a low-grade squamous intraepithelial lesion (LSIL; n = 341) or a high-grade squamous intraepithelial lesion (HSIL; n = 499) and invasive cervical cancer (ICC) (n = 140) groups. Disordered logistic regression analysis was used to test the relationship between different degrees of cervical lesions, HPV16/18 infection status, positive rate of p16^INK4a (p16), Ki-67 expression, and patient's age in SIL and ICC (270/980 cases) patients. HPV52 (4.7%) was the most prevalent HPV type, followed by HPV16 (3.3%) and HPV58 (2.6%). HPV16 was the most common HPV in SIL, peaking at the age of 30-39. The HPV16 infection rate was significantly higher in HSIL than in LSIL patients; moreover, HPV16, HPV18, and HPV51 infection rates were significantly higher in ICC patients than in HSIL (Bonferroni-adjusted p < 0.0167). The presence of HPV16/18 was also associated with a higher risk of developing HSIL from LSIL (odds ratio [OR] = 9.198, 95% confidence interval [CI]: 2.76-127.49). The increased p16 expression and HPV16/18 were associated with the increased risk of cancer progression (OR = 1.092, 95% CI: 1.03-1.36; OR = 1.495, 95% CI: 1.23-2.19, respectively). The identified hrHPV genotypes in cervical lesions can serve as a baseline indicator for future vaccine assessment in Zhejiang, China.

Understanding the Molecular Mechanism of miR-877-3p Could Provide Potential Biomarkers and Therapeutic Targets in Squamous Cell Carcinoma of the Cervix

No therapeutic targets and molecular biomarkers are available in cervical cancer (CC) management. In other cancer types, micro-RNA-877-3p (miR-877-3p) has been associated with events relevant for CC development. Thus, we aimed to determine miR-877-3p role in CC. miR-877-3p levels were examined by quantitative-PCR in 117 cervical lesions and tumors. Effects on CC cell proliferation, migration, and invasion were evaluated upon anti-miR-877-3p transfection. miR-877-3p dependent molecular mechanism was comprehensively explored by proteomics, dual-luciferase reporter assay, western blot, and immunohistochemistry. Cervical tumors expressed higher miR-877-3p levels than benign lesions. miR-877-3p promoted CC cell migration and invasion, at least partly by modulating cytoskeletal protein folding through the chaperonin-containing T-complex protein 1 complex. Notably, miR-877-3p silencing synergized with paclitaxel. Interestingly, miR-877-3p downregulated the levels of an in silico-predicted target, ZNF177, whose expression and subcellular location significantly distinguished high-grade squamous intraepithelial lesions (HSILs) and squamous cell carcinomas of the cervix (SCCCs). Cytoplasmic ZNF177 was significantly associated with worse progression-free survival in SCCC. Our results suggest that: (i) miR-877-3p is a potential therapeutic target whose inhibition improves paclitaxel effects; (ii) the expression and location of its target ZNF177 could be diagnostic biomarkers between HSIL and SCCC; and (iii) cytoplasmic ZNF177 is a poor-prognosis biomarker in SCCC.

Absence of Nuclear p16 Is a Diagnostic and Independent Prognostic Biomarker in Squamous Cell Carcinoma of the Cervix

The tumor-suppressor protein p16 is paradoxically overexpressed in cervical cancer (CC). Despite its potential as a biomarker, its clinical value and the reasons for its failure in tumor suppression remain unclear. Our purpose was to determine p16 clinical and biological significance in CC. p16 expression pattern was examined by immunohistochemistry in 78 CC cases (high-grade squamous intraepithelial lesions (HSILs) and squamous cell carcinomas of the cervix –SCCCs). CC cell proliferation and invasion were monitored by real-time cell analysis and Transwell^® invasion assay, respectively. Cytoplasmic p16 interactors were identified from immunoprecipitated extracts by liquid chromatography-tandem mass spectrometry, and colocalization was confirmed by double-immunofluorescence. We observed that SCCCs showed significantly more cytoplasmic than nuclear p16 expression than HSILs. Importantly, nuclear p16 absence significantly predicted poor outcome in SCCC patients irrespective of other clinical parameters. Moreover, we demonstrated that cytoplasmic p16 interacted with CDK4 and other unreported proteins, such as BANF1, AKAP8 and AGTRAP, which could sequester p16 to avoid nuclear translocation, and then, impair its anti-tumor function. Our results suggest that the absence of nuclear p16 could be a diagnostic biomarker between HSIL and SCCC, and an independent prognostic biomarker in SCCC; and explain why p16 overexpression fails to stop CC growth.