The Ink4a/Arf locus encodes two structurally unrelated tumor suppressor proteins, p16 and p14 (murine p19). Invariant inactivation of either the p16-cyclin D/CDK-pRb pathway and/or p53-p14 pathway occurs in most human tumors. Cyclin D1 is frequently overexpressed in breast cancer cells contributing an alternate mechanism inactivating the p16/pRb pathway. Targeted overexpression of cyclin D1 to ...

The aim of this study was to explore the relationship between HPV16 infection, p16 protein expression and prognosis in patients with hypopharyngeal carcinoma. Totally 46 cases of hypopharyngeal carcinoma specimens were selected from January 1, 2004 to December 31, 2011 in Tangshan Union Hospital. PCR-reverse dot blot hybridization was used to detect infection of HPV16, and SP immunohistochemica...

Objective To investigate the expression of p16, cyclin D1, retinoblastoma tumor suppressor protein (Rb) and MIB-1 in skull base chordoma and chondrosarcoma tissues, and to determine the clinicopathological significance of the above indexes in these diseases. Methods A total of 100 skull base chordoma, 30 chondrosarcoma, and 20 normal cartilage tissue samples were analyzed by immunohistochemis...

The differential diagnosis between atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDLPS) and dedifferentiated liposarcoma (DDLPS) from their morphologic counterparts is challenging. Currently, the diagnosis is guided by MDM2 and CDK4 immunohistochemistry (IHC) and is confirmed by the amplification of the corresponding genes. Recently, p16 IHC has been proposed as a useful diagno...

OBJECTIVE To demonstrate the roles of p16(INK4a) in the senescence of human chondrocytes and the progression of osteoarthritis (OA). METHODS Immunohistochemistry and reverse transcriptase polymerase chain reaction (RT-PCR) were performed to examine p16(INK4a) expression in fetal, normal age-matched and OA cartilage, and Western blot was used in primary cultured chondrocytes from different ori...

BACKGROUND Upregulation of the cell cycle associated genes, p16/CDKN2 and the retinoblastoma susceptibility gene (Rb), is commonly seen during the proliferation of normal cells. An inverse relation between the expression of p16/CDKN2 and Rb has been noted in many tumours, but has not yet been determined in oesophageal squamous carcinoma. AIMS To investigate p16/CDKN2 genetic alterations and b...

PURPOSE Hypermethylation of the CpG island of p16(INK4a) occurs in a significant proportion of colorectal cancer (CRC). We aimed to investigate its predictive role in CRC patients treated with 5-fluorouracil, leucovorin, irinotecan (FOLFIRI), and cetuximab. MATERIALS AND METHODS Pyrosequencing was used to identify KRAS mutation and hypermethylation of 6 CpG island loci (p16, p14, MINT1, MINT2...

Overexpression of the p16 tumor suppressor, but also deletion of its gene locus 9p21, is linked to unfavorable tumor phenotype and poor prognosis in breast cancer. To better understand these contradictory observations, and to clarify the prognostic impact of p16 expression and 9p21 deletion, a tissue microarray (TMA) with 2,197 breast cancers was analyzed by fluorescence in-situ hybridization a...

With increasing frequency during serial passage in culture, primary human keratinocytes express p16(INK4A) (p16) and undergo senescence arrest. Keratinocytes engineered to express hTERT maintain long telomeres but typically are not immortalized unless, by mutation or other heritable event, they avoid or greatly reduce p16 expression. We have confirmed that keratinocytes undergo p16-related sene...

AIM p16 Methylation frequently occurs in carcinogenesis. While it has been hypothesized that the p16 methylation states are dynamically maintained in cancer cells, direct evidence supporting this hypothesis has not been available until now. METHODS A fusion cell model was established which reprogrammed the native DNA methylation pattern of the cells. The methylation status of the p16 alleles ...