1) To analyze the expression of Ki-67, p53 and p16(INK4a) in cervical cancer, 2) to correlate the relative expression of these proteins as well as clinical parameters with the stage of disease, and 3) to determine the HPV DNA prevalence and subtype distribution.
P16INK4a hypermethylation was significantly associated with the increased risk of LSIL, HSIL and CC, with the pooled ORs of 3.26 (95% CI: 1.86-5.71), 5.80 (95% CI: 3.80-8.84) and 12.17 (95% CI: 5.86-25.27), respectively.
All 3 cases of vulvar carcinoma showing homozygous deletions of p16INK4 and p15INK4B were at advanced clinical stage (stage III-IV), while all 7 cases of cervical carcinoma and 2 cases of ovarian carcinoma showing homozygous deletion of p16INK4 were at early stage (stage I-II).
And SNP at C580T of p16 gene was found to be negatively associated with the risk of cervical cancer (P=0.0004, OR=0.04, 95% CI=0.002-0.63). p16 (540C/580T) has emerged as a major risk haplotype (P=0.033, OR=1.47, 95% CI=1.05-2.07) whereas p16 (540G/580T) as a chief protective haplotype (P=0.014, OR=0.39, 95% CI=0.18-0.83) for the development of cervical cancer among Indian women.
By overlapping these dysregulated genes, we found that three genes, including CDKN2A, IL1R2 and RFC4, were not only changed in HSIL, but also significantly changed in SCC, indicating that their dysregulation may contribute to cervical cancer development.
Carcinogenesis of cervical cancer has been investigated, and p16(INK4a) overexpression in squamous cell carcinoma of the cervix has been reported as a result of infection by human papillomavirus (HPV) (eg, HPV 16), and the consequence of the retinoblastoma (Rb) protein inactivation by HPV E7 protein.
Correlation between methylation status of p16 gene and poor menstrual hygiene was significant (p=0.006), high parity cases showed methylation of p16 gene (p=0.031) with increased risk up to 1.86 times for cervical cancer and smoking was a strong risk factor associated with cervical cancer.
Deletions or point mutations in the p15INK4B or p16INK4A gene may not be required for the development of HPV-positive cervical cancer or for establishment of cervical cancer cell lines.
HNRNPA1 (92%) and p16 (91%) presented the two highest diagnostic accuracies for cervical carcinoma, which were superior to those of SRSF3 (75%), SRSF1-HMws (72%), CEA (72%), SCCA (59%), and SRSF1-Total (55%).
However, there is little information on the possible impact of the HPV genotype and p16 immunostaining on the clinicopathological features or their prognostic value in cervical carcinoma.
Immunohistochemical p16ink4a expression is associated with HPV infection in HSIL and cervical cancer, suggesting a role of p16 as a biomarker of HPV-associated cervical lesions.
Immunohistochemical expression of p16 in ovarian tumors can guide the diagnosis of metastasis from HPV-related cervical cancer, but p16 positivity is nonspecific.
Immunohistochemistry of p16INK4A staining shows nil (0/25) expression in the cervicitis patients, 72% (18/25) in CIN patients and 100% (25/25) in cervical carcinoma.
Ki-67 and P16 proteins in cervical cancer and precancerous lesions of young women and the diagnostic value for cervical cancer and precancerous lesions.