Breast cancer-specific mortality was strongly associated with promoter methylation of p16 [HR and 95% CI: 3.53 (1.83-6.78)], whereas the associations with of BRCA1 and APC were less pronounced [HR and 95% CI: 1.81 (1.18-2.78) and 1.46 (0.98-2.17), respectively].
CDKN2 is not deleted with high frequency in primary breast carcinomas, and the p16 gene does not play a role in breast carcinogenesis via this mechanism.
Aberrant CDH1 methylation was detected in 25% (9/36) of primary tumors and 20% (7/36) of plasma samples. p16 and/or CDH1 hypermethylation was found in 31% (11/36) of primary breast carcinomas and 82% (9/11) of breast cancer patients with tumoral methylation showing identical epigenetic changes in plasma.
After eliciting a prior history of multiple primary melanomas and breast cancer, she was tested for and shown to be a carrier for a germline mutation in CDKN2A.
Alterations in polymorphic markers selected because they had been found to show a high rate of alterations in breast cancer in previous studies (D17S855, D17S654, D16S421, TH2, D10S197, and D9S161), as well as mutations in the p53 gene and aberrant methylation at the first exon of p16INK4a, were used to identify and characterize tumor and plasma DNA.
Although the significance of p16(INK4a) expression in breast cancer is not fully understood, we have shown that p16(INK4a) is strongly expressed in breast cancers with basal-like phenotype.
ASSET analyses identified four SNPs significantly associated with multiple cancers: rs3731239 (CDKN2A intronic) with ESCC, GC and BC (P = 3.96 × 10(-) (4)); rs10811474 (3' of IFNW1) with RCC and BrC (P = 0.001); rs12683422 (LINGO2 intronic) with RCC and BC (P = 5.93 × 10(-) (4)) and rs10511729 (3' of ELAVL2) with LC and BrC (P = 8.63 × 10(-) (4)).
CDK4 expression did not correlate with cyclin D1 expression or the survival data. p16 expression was associated with Human Epidermal Growth Factor Receptor 2 (HER2) negativity and increased breast cancer-specific survival and disease-free survival.
Comparison of the molecular data and pathological information of the samples suggested that p16(INK4A) gene might be inactivated at the early stages in breast cancer.
Conversely, protein p16 expression, although heterogeneously distributed within the section, is considerably higher in breast carcinoma as compared to fibroadenoma in both tumoral and non-tumoral epithelia and stroma.
Despite the frequent deletion of INK4 in breast cancer cell lines, no evidence was obtained for INK4 deletions in DNA from 45 primary breast carcinomas.
Earlier studies have shown that CDKN2A excludes the predisposition of germline variants, but interestingly shares common breast cancer germline variants with other carcinomas.
Epoxy clerodane diterpene inhibits MCF-7 human breast cancer cell growth by regulating the expression of the functional apoptotic genes Cdkn2A, Rb1, mdm2 and p53.