Here, we explored the association of two genetic variants in the 9p21 region, CDKN2A/B, rs10811661, and rs1333049 for the first time in 273 subjects with, or without ESCC.
The ORs of p16 methylation for genotype CT and TT were 1.98 (95% CI 1.01-3.89) and 17.79 (95% CI 2.26-140.22) in EPL, 4.86 (95% CI 2.48-9.50) and 20.40 (95% CI 2.53-164.81) in ESCC, respectively.
Consistent with the immunohistochemistry results, p16 was expressed in tumor tissue from nude mice that had been transplanted with the modified human ESCC lines.
<b>CONCLUSIONS:</b> These results suggest that hr-HPV types are not associated with the development of ESCC and that p53 and p16 protein expression have no relationship with HPV infection in normal or cancerous esophagus.
Mutations in TP53 and CDKN2A and copy number alterations in 11q (contains CCND1), 3q (contains SOX2), 2q (contains NFE2L2), and 9p (contains CDKN2A) were considered to be trunk variants; these were dominant mutations detected at high frequencies in clones of paired IEN and ESCC samples.
By using multiplex PCR, we determined the prevalence of high risk HPV in ESCC, and evaluated the immunohistochemical expression of p16 and p53, molecular markers related to esophageal carcinogenesis in order to verify the potential influence of these variables in patients's survival.
The p14ARF/MDM2/ TP53 pathway is known to play an important role in tumor progression by cell cycle control, although the association between this pathway and the prognosis of esophageal squamous cell carcinoma (ESCC) is unclear.
The pooled results showed no significant relationship between p16INK4a expression and HPV infection in ESCC based on overall HPV types (OR: 1.79, 95% CI: 0.69-4.66, p = 0.235).
Although the cancer-associated genes TP53, PIK3CA, CDKN2A and their pathways showed no significant difference between stage I and stage III tumors, we identified and validated a prevalence of mutations in NOTCH1 and in the NOTCH pathway that indicate that they are involved in the preclinical and early stages of ESCC.
CtBP2 was also demonstrated to contribute to the proliferation of esophageal squamous cell carcinoma (ESCC) cells through a negative transcriptional regulation of p16(INK4A).
This systematic review reports great regional variation in the prevalence of HPV in ESCC and suggests that p16(INK4a) is not a reliable marker of HPV status in ESCC.
The aberrant promoter methylation of p14ARF is a common phenomenon in ESCC, which may be an important mechanism of downregulating p14ARF mRNA expression.
Collectively, all results suggested that CtBP2 might contribute to the progression of ESCC through a negative transcriptional regulation of p16(INK4A).
The recurrence was associated with hypermethylation of the genes cell adhesion molecule 1 (CADM1) (P = .003), deleted in colon carcinoma (DCC) (P = .04), or cyclin-dependent kinase inhibitor 2A (p14) (P = .02) in patients with stage I ESCC.
In the meta-analyses by ASSET, four SNPs (rs3731239 in CDKN2A, rs615552 and rs573687 in CDKN2B and rs564398 in CDKN2BAS) showed significant associations with ESCC and EC (P<2.46 × 10(-4)).
Abnormal expression of p16 and p53, but not MDM2, was significantly higher in the tumoral tissue. p53 was concomitantly accumulated in ESCC tumor along with MDM2 overexpression and p16 negative expression.
DNAs from 44 fresh tumor tissues and 19 non-tumor adjacent normal tissues, obtained from 44 patients affected by SCC of esophagus (SCCE), were studied for methylation at the CDKN2A/p16 gene promoter by methylation-specific polymerase chain reaction assay.