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.
Although loss of functional p53 pathway and loss of Ink4a/Arf in human pancreatic acinar cell carcinoma (PACC) and pancreatic neuroendocrine tumor (PanNET) are identified, their direct roles in tumorigenesis of PACC and PanNET remain to be determined.
The objectives of this study were to document expression of the cyclin-dependent kinase inhibitor 2A (p16) tumor-suppressor protein p16<sup>INK4A</sup> as a biomarker of cervical carcinogenesis or of malignant potential and to evaluate whether its expression differs between lesions associated with vaccine and nonvaccine high-risk (HR) human papillomavirus (HPV) genotypes.
Since overexpression of cell cycle regulatory protein p16 was immunohistochemically evident in tumor tissue, human papillomavirus infection was considered as a causative factor in the carcinogenesis.
Importantly, our results suggest that the low expression of RARβ, may induce the down regulation of p16(INK4a), chronic inflammation and decreased apoptosis and may be involved in vulnerability to HR-HPV and early stage cervical carcinogenesis.
In ovarian epithelial carcinogenesis, p16 and p53 show higher immunohistochemical staining frequencies in malignant tumors and are associated with poor prognoses. p14 was only analyzed in carcinomas, with conflicting results.
These results indicate that RD deletion and BMI1 overexpression frequently occur in the early stage of oral carcinogenesis and BMI1 overexpression may downregulate the transcription of p16 and p14 through interfering with RD.
Oncogene Bmi-1 was shown to be a functional target of miR-218, and the main downstream targets signaling, P16(Ink4a) and P14(ARF), were activated in Hotair-suppressed tumorigenesis.
Regarding the oncogenesis of primary brain tumors, it was shown that changes in functions of p16 and mouse double minute 2 homolog (MDM2) are related to tumor pathogenesis by enhancing cell proliferation and malign development.
Furthermore, knockdown of Bmi-1 expression in CD133(+) cells led to inhibition of cell growth, colony formation, cell invasion in vitro, and tumorigenesis in vivo, through up-regulation of p16(INK4A) and p14(ARF).
Indicaxanthin exhibited anti-proliferative activity in all cell lines but HT29, induced demethylation in the promoters of some methylation-silenced onco-suppressor genes involved in colorectal carcinogenesis (p16INK4a, GATA4, and ESR1), and left unchanged others which were basally hypermethylated (SFRP1 and HPP1).
We hypothesize that the presence of the fourth product, pALT(INK4a/b) of the INK4a/b locus in the naked mole rat, contributes to the increased resistance to tumorigenesis of this species.
We have shown that an epigenetic diet can influence both cellular longevity and carcinogenesis through the modulation of certain key genes that encode telomerase and p16.
There is a need for identification of biomarkers to identify people at risk of esophageal cancer. p16 is an essential G1 cell cycle regulatory gene whose loss of function is associated with carcinogenesis.
p16(INK4a) is a tumor suppressor gene, frequently hypermethylated in breast cancer; this epigenetic silencing of p16(INK4a) occurs early in carcinogenesis.
Crude odds ratios with 95% confidence intervals were calculated using the random-effects model which were used to assess the strength of relationship between p16 methylation and lung carcinogenesis.
QPCR demonstrated in patients ≤45 years a higher expression of genes that are associated with carcinogenesis (CTNNB1, STK11, CDKN2A, HGF, MET) as well as tumor suppressors that constitute an enhanced radio-sensitivity (ATM, BRCA1E2F1, FHIT).