Absence Of P16 Expression Research Articles

Comparison among Various Prognostic Pathologic Markers Revealed Significantly Poorer Prognosis in Non-basal-like than in Basal-like Triple Negative Breast Cancer

Objective: To find the incidence and prognosis of basal-like (TNB) and non-basal-like (TNN) in triple negative breast cancer. Methods: Triple negative breast cancer (TN) cases were retrospectively reviewed and biomarkers studied on tissue microarray for ER, PR, HER2, Ki67, basal cytokeratins (CK5/6, CK14, CK17), EGFR, CD117, p63, p53, vimentin, CK7, CK8/18, CK19, BCL2, p16, WT1, and cyclin D1. The patients were reclassified according to ER, PR, HER2, Ki67 index, basal CKs and EGFR results into: lumA, lumB, HER2+, TNB and TNN. Results: From 2007 to 2010, there were 193 female patients (120 TNB, 17 TNN, 42 lumB, and 14 HER2+). There were 184 (95.3%) invasive ductal carcinoma (IDC). All 17 TNN were IDC. High grade histology accounted for 71.5%. The median follow up time was 62.93 months. There were no significant differences in age, histologic grade, and tumor size between TNB and TNN while TNN had significant number of higher stage (p=0.028), axillary lymph node metastasis of more than 3 nodes (p=0.005) and lower disease free survival (DFS, p= 0.004) and overall survival (OS, p=0.001). TNN also had the poorest prognosis among the four subtypes.Tumor size and axillary nodal involvement were the independent predictors for DFS and OS. Absence of EGFR expression was an independent factor for lower DFS and OS in TN. Absence of CK8/18 expression was an independent factor for lower DFS in any combined group and OS in the combined TN and lumB group. Absence of p16 expression was an independent factor for lower DFS and OS of all cohort. Conclusion: TNN accounted for12.3% of TN and had poorer prognosis. Tumor size and axillary nodal involvement were the independent predictors for DFS and OS. Absence of EGFR, CK8/18 or p16 expression had influence on survival in TN or combined group.

P16 Immunohistochemical Expression as a Surrogate Assessment of CDKN2A Alteration in Gliomas Leading to Prognostic Significances.

CDKN2A is a tumor suppressor gene encoding the p16 protein, a key regulator of the cell cycle. CDKN2A homozygous deletion is a central prognostic factor for numerous tumors and can be detected by several techniques. This study aims to evaluate the extent to which immunohistochemical levels of p16 expression may provide information about CDKN2A deletion. A retrospective study was conducted in 173 gliomas of all types, using p16 IHC and CDKN2A fluorescent in situ hybridization. Survival analyses were performed to assess the prognostic impact of p16 expression and CDKN2A deletion on patient outcomes. Three patterns of p16 expression were observed: absence of expression, focal expression, and overexpression. Absence of p16 expression was correlated with worse outcomes. p16 overexpression was associated with better prognoses in MAPK-induced tumors, but with worse survival in IDH-wt glioblastomas. CDKN2A homozygous deletion predicted worse outcomes in the overall patient population, particularly in IDH-mutant 1p/19q oligodendrogliomas (grade 3). Finally, we observed a significant correlation between p16 immunohistochemical loss of expression and CDKN2A homozygosity. IHC has strong sensitivity and high negative predictive value, suggesting that p16 IHC might be a pertinent test to detect cases most likely harboring CDKN2A homozygous deletion.

Telomerase reverse transcriptase promoter mutations and solar elastosis in cutaneous melanoma.

The aims of this study were to assess the prognostic potential of solar elastosis grading and telomerase reverse transcriptase (TERT) promoter mutations (TERTp) in melanoma and to evaluate whether an association between solar elastosis and TERTp exists. Solar elastosis in the dermis was evaluated in hematoxylin and eosin-stained whole slides from 486 malignant melanomas. Pyrosequencing was used to detect TERTp in 189 samples. There was no association between solar elastosis and TERTp (P=0.3). Severe elastosis was associated with older age (P<0.0001), ulceration (P=0.03), and location in the head/neck region (P<0.0001). The absence of elastosis was associated with younger age (P<0.0001), benign nevus remnants (P=0.001), and a positive BRAF V600E expression (P<0.0001). Severe elastosis predicted a worse relapse-free survival (hazard ratio: 2.18; 95% confidence interval: 1.30-3.64; P=0.003). However, it was not independent of age. TERTp was not associated with any adverse prognostic or clinicopathological outcome, nor any mitogen-activated protein kinase-related protein expressions. However, at a cutoff corresponding to the sensitivity of Sanger sequencing, TERTp predicted melanoma-specific death independently of age, and was associated with Breslow thickness, ulceration, tumor stage at diagnosis, BRAF V600E oncoprotein, and absence of p16 expression. In conclusion, TERTp were not related to severe elastosis and may thus be triggered by both chronic and acute intermittent sun exposure, the latter not visible on ordinary hematoxylin and eosin-stained slides. Neither TERTp nor severe elastosis predicted an adverse outcome in melanoma. An absence of elastosis was seen in younger melanoma patients and may be used to select those melanomas originating in a nevus, which often harbors a BRAF mutation.

Contribution of chromosome 9p deletion and Bcl1, Myc and p16 immunohistochemistry to the characterization of oligodendrogliomas

Molecular studies suggest that anaplastic oligodendrogliomas (OIII) can be subdivided into clinically relevant subgroups. We analyzed a retrospective series of 40 consecutive OIII operated at our institution and compared them to 10 grade II oligodendrogliomas (OII). Chromosome 9p status was compared to Bcl1, Myc and p16 expression by immunohistochemistry, clinical and histological data, and to event free survival (EFS) and overall survival (OS).Chromosome 9p deletion was observed in 55 % of OIII (22/40) but not in OII, and correlated with both OS and EFS. Bcl1 expression was significantly higher in OIII (45 % versus 14% for OII) and correlated with MIB-1 expression, vascular proliferation, tumour necrosis and a shorter EFS. Myc expression was correlated with histologic grade (27% in OII, 35% in OIII) and to a shorter EFS in chromosome 9p non-deleted OIII. p16 expression was not correlated with grade but revealed two distinct expression profiles according to chromosome 9p status. In 9p non-deleted oligodendrogliomas, p16 hyperexpression was correlated with shorter OS in both OII and OIII whereas absence of p16 expression was correlated with shorter OS and EFS in 9p deleted OIII.

P16 protein expression and correlation with clinical and pathological features in osteosarcoma of the jaws: Experience of 37 cases.

In literature, no markers have been reported as predictive and prognostic factors in osteosarcoma of the jaw. A retrospective analysis of p16 expression was performed in 37 patients with high-grade osteosarcoma of the jaw to investigate its potential prognostic and predictive value. p16 positivity was found in 56.7% of cases. The absence of p16 expression was associated with an adverse disease-free survival (P = .003). At the multivariate Cox regression, positive margins were the only independent factor. In the subgroup of 17 patients who underwent neoadjuvant chemotherapy, a significant association was noted between p16 expression and pathological response to chemotherapy (P = .015) and the negativity of p16 increased the risk of negative outcome (P = .01). Our data indicate that the wide surgical margin is the most important prognostic factor. The expression of p16 confers greater sensitivity to chemotherapy and its loss of expression is associated with a worse prognosis.

P16 expression as a prognostic and predictive marker in high-grade localized osteosarcoma of the extremities: an analysis of 357 cases

The potential prognostic and predictive value of p16 in high-grade localized osteosarcoma of the extremities has been recently investigated in small series of cases, and the results from different studies were somewhat controversial. A retrospective immunohistochemical analysis of p16 expression was performed in a series of 357 patients, included in different neoadjuvant chemotherapy protocols from 1986 to 2010, to explore its potential prognostic and predictive value. Immunohistochemistry was performed with a commercially available p16 monoclonal mouse antibody. Follow-up data were available in all cases with a median of 120 months. Positivity for p16 was detected in 70.6% (252/357) of cases. The p16 expression did not differ by age, sex, tumor site, histologic subtype, tumor volume, surgical margin, serum alkaline phosphatase levels, and lactate dehydrogenase levels. In the different chemotherapy protocols included, the incidence of p16 expression was similar. The absence of p16 expression was significantly associated with an adverse disease-free survival (P=.04) and overall survival (P=.05) when compared with the presence of p16 expression. At the multivariate Cox regression analysis, p16 expression lost its prognostic significance. Multivariate logistic regression analysis showed that as p16 expression was the only statistically significant parameter to predict the pathological response to neoadjuvant chemotherapy treatment with an odds ratio of 3.025 (P<.001) for "good" chemotherapy response. Our data indicate that the negative expression of p16 is associated with a reduced rate of good response to primary chemotherapy and to a worse probability of survival, although it was not confirmed as an independent prognostic biomarker after multivariate analysis.

P16 protein is upregulated in a stepwise fashion in colorectal adenoma and colorectal carcinoma.

Background/Aims:p16 is tumor suppressor gene acting as a cell cycle regulator. The present study was conducted to compare p16 expression in normal, dysplastic, and malignant colonic mucosae, and to explore its relation to clinicopathological variables and follow-up data in colorectal carcinoma (CRC).Patients and Methods:Tissue microarrays were performed from 25 normal colonic mucosae, 41 colonic adenomas, and 191 CRC, with corresponding 50 nodal metastases. Immunohistochemistry was performed using anti-p16 antibody, sections were scored, and statistical analysis was performed. K-ras mutation detection was also performed.Results:Immunoexpression of p16 was significantly higher in CRC than in adenomas (P = 0.033) and normal colonic mucosa (P = 0.005). There was no statistically significant difference between p16 expression in CRC and nodal metastasis. There was no significant association between p16 immunoexpression in CRC and all clinicopathological data and survival probability. K-ras mutations were detected in 34% of CRC. However, there was no correlation between K-ras status and p16 expression (P = 0.325).Conclusion:Absence of p16 expression is correlated to a benign course of CRC adenomas. p16 has a key role in CRC progression and can be used as a marker for colorectal adenoma. On the other hand, it has no role as a predictive and/or prognostic factor in CRC. Further extended studies are required to explore the role of p16 as indicator of premalignant lesions in the colon and to test its relation with CRC histological grade, as well as to test its value as a new therapeutic target.

The Prevalent, Features and Prognostic Impact of Deletion p16 in Patients with Adult Acute Lymphoblastic Leukemia

Background and objective: Deletion of chromosome 9p21 is a crucial event for acute lymphoblastic leukemia (ALL). 9p21.3 genes encode three cell cycle inhibitory proteins: p15INK4b, p16CDKN2A, and p14ARFT. Recently studies show that p16 (CDKN2A) alleles were hypermethylated at CpG islands in ALL patients and delation p16 was associated with poor prognosis in childhood ALL. However, the prognostic significance of the deletion p16 in adult ALL leukemia is controversial, so the aim of the present study was to investigate the prevalence, feature and specific prognostic relevance of delation p16 in Chinese ALL patients from a single center in China.Patients and Methods: A total of 513 newly diagnosed adult ALL patients were identified retrospectively from the database of ALL between January 2008 and December 2013 at our center. We Detected delation p16 by interphase fluorescence in ituhybridization (I-FISH) and analyzed their clinical data retrospectively.Results: Of 513 cases, the prevalence of having either heterozygous or homozygous p16 deletions was 32%. p16 deletion were identified in 27% of newly diagnosed Philadelphia positive(Ph+) patients by univariate analysis, patients with p16 deletion had no significant difference compared with wild-type patients in terms of sex, age, white blood cells (WBC) count at diagnosis,BM blast percentage,chromosome karyotype,extra infiltration and CR I rate. The patients with p16 deletion was more likely to relapse comparaed with wild-type patients (P=0.03), and at relapse, we found a strong trend in the detection rate of p16 loss (41%) compared with diagnosis (P=0.01), suggesting that loss of this genomic region may be involved in disease progression. Of note, in newly diagnosed Ph+ALL with delation p16 were likely relapse even in the patients who treated with allogeneic hematopoietic stem cell transplantation (P=0.03). In addition, deletion p16 were significantly associated with poor outcomes in terms of overall survival (P=0.01), disease free-survival (P< 0.001), and cumulative incidence of relapse (P< 0.001).Conclusion: In our study, the absence of p16 expression seems to a poor prognostic marker in adult ALL patients. However, how to improve the survival of these patients need further study. DisclosuresNo relevant conflicts of interest to declare.

P16 Protein and Gigaxonin Are Associated with the Ubiquitination of NFκB in Cisplatin-induced Senescence of Cancer Cells

The molecular mechanism of p16-mediated senescence in cisplatin-treated cancer cells is not fully understood. Here we show that cisplatin treatment of head and neck cancer cells results in nuclear transport of p16 leading to a molecular modification of NFκB. Chromatin immunoprecipitation assays show that this modification is associated with the inhibition of NFκB interacting with its DNA binding sequences, leading to decreased expression of NFκB-transcribed proteins. LCMS proteomic analysis of LAP-TAP-purified proteins from HeLa cells containing a tetracycline-inducible GFP-S peptide-NFκB expression system identified gigaxonin, an ubiquitin E3 ligase adaptor, as an NFκB-interacting protein. Immunoblotting and siRNA studies confirmed the NFκB-gigaxonin interaction and the dependence of this binding on p16-NFκB binding. Using gel shift assays, we have confirmed p16-NFκB and gigaxonin-NFκB interactions. Furthermore, we have observed increased NFκB ubiquitination with cisplatin treatment that is abolished in the absence of p16 and gigaxonin expression. Analysis of 103 primary tumors has shown that increased nuclear p16 expression correlates with enhanced survival of head and neck cancer patients (p < 0.0000542), indicating the importance of nuclear p16 expression in prognosis. Finally, p16 expression is associated with reduced cytokine expression and the presence of human papilloma virus in chemoradiation-sensitive basaloid tumors. However, the absence of p16 expression is associated with enhanced cytokine expression and the absence of human papilloma virus in aggressive tumors. These results clearly demonstrate that nuclear p16 and gigaxonin play an important role in chemosensitivity of head and neck cancers through ubiquitination of NFκB.

Expression of BMI1 and p16 in laryngeal squamous cell carcinoma

The clinical evolution of laryngeal squamous cell carcinoma (SCC) is undetectable with the current staging criteria. To more completely understand the biology of laryngeal SCC, we assessed the expression of the proteins B-cell-specific Moloney murine leukemia virus integration site 1 (BMI1) and p16. We assessed immunohistochemically the expression of BMI1 and p16 in 25 laryngeal SCCs at different stages. High BMI1 expression was detected in 11.7% of glottic tumors and in 50% of supraglottic tumors. No significant differences were observed in the patients' clinical data after they were stratified by the tumor expression of p16. The expression of nuclear BMI1 in the absence of p16 immunoreactivity correlated significantly with the pN status of the primary tumors. Nuclear BMI1 expression in the absence of p16 expression seems to characterize a subset of patients with a high risk of developing lymph node metastasis.

Expression patterns of Bmi‐1 and p16 significantly correlate with overall, disease‐specific, and recurrence‐free survival in oropharyngeal squamous cell carcinoma

The objective of this study was to link expression patterns of B-cell-specific Moloney murine leukemia virus integration site 1 (Bmi-1) and p16 to patient outcome (recurrence and survival) in a cohort of 252 patients with oral and oropharyngeal squamous cell cancer (OSCC). Expression levels of Bmi-1 and p16 in samples from 252 patients with OSCC were evaluated immunohistochemically using the tissue microarray method. Staining intensity was determined by calculating an intensity reactivity score (IRS). Staining intensity and the localization of expression within tumor cells (nuclear or cytoplasmic) were correlated with overall, disease-specific, and recurrence-free survival. The majority of cancers were localized in the oropharynx (61.1%). In univariate analysis, patients who had OSCC and strong Bmi-1 expression (IRS >10) had worse outcomes compared with patients who had low and moderate Bmi-1 expression (P = .008; hazard ratio [HR], 1.82; 95% confidence interval [CI], 1.167-2.838); this correlation was also observed for atypical cytoplasmic Bmi-1 expression (P = .001; HR, 2.164; 95% CI, 1.389-3.371) and for negative p16 expression (P < .001; HR, 0.292; 95% CI, 0.178-0.477). The combination of both markers, as anticipated, had an even stronger correlation with overall survival (P < .001; HR, 8.485; 95% CI, 4.237-16.994). Multivariate analysis demonstrated significant results for patients with oropharyngeal cancers, but not for patients with oral cavity tumors: Tumor classification (P = .011; HR, 1.838; 95%CI, 1.146-2.947) and the combined marker expression patterns (P < .001; HR, 6.254; 95% CI, 2.869-13.635) were correlated with overall survival, disease-specific survival (tumor classification: P = .002; HR, 2.807; 95% CI, 1.477-5.334; combined markers: P = .002; HR, 5.386; 95% CI, 1.850-15.679), and the combined markers also were correlated with recurrence-free survival (P = .001; HR, 8.943; 95% CI, 2.562-31.220). Cytoplasmic Bmi-1 expression, an absence of p16 expression, and especially the combination of those 2 predictive markers were correlated negatively with disease-specific and recurrence-free survival in patients with oropharyngeal cancer. Therefore, the current results indicate that these may be applicable as predictive markers in combination with other factors to select patients for more aggressive treatment and follow-up.

Tissue microarray evidence of association between p16 and phosphorylated eIF4E in tonsillar squamous cell carcinoma

Expression of p16 is a marker for human papillomavirus (HPV)-related carcinogenesis in head and neck cancer. The purpose of this study is to determine if p16 immunoreactivity is associated with aberrant expression of components of the PI3 kinase pathway. A tissue microarray (TMA) was constructed for 46 archived tonsillar squamous cell carcinoma specimens. Clinical demographics of these patients were analyzed, and the TMA was interrogated with antibodies directed against p16, phosphorylated Akt(Ser473), phosphorylated S6(Ser240/244), phosphorylated S6(Ser235/236), phosphorylated 4E-BP1(Thr37/46), phosphorylated eIF4E(Ser209), PTEN, p21, and p53. There was a significant correlation between history of tobacco abuse (>10 pack/years) and absence of p16 expression (p = .01). Expression of p16 was significantly associated with immunoreactivity of p21 (p = .02), PTEN (p = .02), and phosphorylated eIF4E (p = .03). There was no evidence of association between p16 status and expression of phosphorylated S6, phosphorylated 4E-BP1, or p53. p16 positive tonsillar squamous cell carcinoma is characterized by expression of phosphorylated eIF4E that may occur via a mammalian target of rapamycin (mTOR)-independent mechanism.

5-ALA Photodynamic Therapy Eliminates Resistant Barrettʼs Cells

Purpose: Photodynamic therapy (PDT) with sodium porfimer has been shown to decrease both high grade dysplasia and cancer formation in Barretts esophagus. However, we have previously shown that sodium porfimer mediated PDT is not as effective in patients who are p16 deficient which is important in cell cycle regulation. p16 was associated with a substantial risk of treatment failure defined as persistence of high-grade dysplasia or advancement to cancer. Recently, 5-amino levulinic acid (ALA) has become available for use in the United States. It is important to determine if ALA mediated PDT has advantages over sodium porfimer mediated PDT other than shorter duration of cutaneous phototoxicity and decreased stricture formation. Our aim was to determine if ALA mediated PDT cell killing was independent of p16 status. Methods: A Barretts epithelial cell line immortalized with H-Tert (human telomerase) was provided to us (RF Souza, Texas Southwester) which has been described as having normal cell functions other than an absence of p16 expression. We used an adenovirus-mediated p16 to infect and re-introduce p16 expression to this cell line. We then compared the effect of PDT with ALA in cells with and with p16. After the cells were estabished in culture, ALA was provided in concentrations of 0, 2.5, 5, 10, 25, 50, 100, and 250 ug/ml and incubated for 6 hours prior to photoradiation with a broadband xenon light source for a total of 20 J/square cm. Cells were then observed for 4 days after which cell death was assessed with propidium iodide. Results: 5-ALA mediated cell death was similar in both p16+ and p16- Barretts epithelial cells (P > 0.05). There was no significant difference in cell death at any concentration of ALA. Control cells had less than 5% cell death while those that were treated with 50 ug/ml of 5-ALA had about 20% cell death. Treatment with either 100 or 250 ug/ml of 5-ALA produced 90% cell death. The LD50 for 5-ALA was 68 ug/ml. Conclusion: 5-ALA mediated PDT appears to kill Barretts cells resistant to sodium porfimer mediated PDT. 5-ALA may be able to eliminate Barretts epithelium in those 20% of patients with high grade dysplasia who have failed sodium porfimer.

P16 expression in primary malignant melanoma is associated with prognosis and lymph node status

Lymph node (LN) status is an important prognostic factor in melanoma patients. p16 expression and proliferation rate (MIB-1) of primary melanomas have been suggested as a marker of metastatic potential. In this study, the correlation of p16 expression and the proliferation rate (MIB-1) with LN status and tumor-specific survival was investigated in primary melanomas. MIB-1 and p16 expression were analyzed by immunohistochemistry in 64 patients with primary cutaneous melanoma. Thirty four nevi were used as control. All patients underwent sentinel lymph node staging. Three different p16 staining patterns were observed: a combination of nuclear and cytoplasmic staining, only cytoplasmic staining and absence of p16 expression. All 34 nevi displayed a nuclear and cytoplasmic p16 staining, whereas p16 was negative in 14 of 64 (22%) melanomas. The level of p16 expression gradually decreased from benign nevi to melanoma without metastasis to melanoma with metastasis. There was a significant correlation between cytoplasmic p16 expression and absence of metastasis (p < 0.05). Death of disease correlated with absence of p16 immunostaining (p = 0.01). MIB-1 expression was not associated with survival. These results confirm the relevance of p16 expression as a prognostic marker in melanoma patients. In addition, it was shown that cytoplasmic immunostaining for p16 in primary melanoma might serve as a predictor of the LN status. Therefore, immunohistochemical evaluation for p16 expression is of potential value for treatment planning in melanoma surgery.

Loss of p16 expression is associated with histological features of melanoma invasion.

While mutations of CDKN2A are associated with melanoma predisposition, the precise role of its gene product p16 in the development of sporadic melanoma is less clearly understood. We sought to determine the prevalence of p16 expression using immunohistochemical analysis in a population-based sample of melanoma tumours, and also to identify histological, phenotypic and environmental factors associated with the presence or absence of p16 expression. We conducted face-to-face interviews with 108 patients newly diagnosed with melanoma to ascertain their history of sun exposure, and recorded various phenotypic parameters. Paraffin sections of tumours from these patients were stained with an anti-p16 monoclonal antibody following antigen retrieval. Overall, 52 (48%) tumours expressed p16; nodular melanomas had significantly lower levels of p16 immunoreactivity than superficial spreading melanomas (P = 0.015). While no association was found between p16 expression and host phenotype, loss of p16 staining was associated with thicker lesions (p = 0.084) and a high mitotic index (P = 0.013). Taken together, these findings are consistent with loss of p16 being a late event in the progression of sporadic primary melanomas, being associated with tumours of a more aggressive nature.

5' CpG island methylation of p16 is associated with absence of p16 expression in glioblastomas.

Recent evidence shows that transcriptional silencing as a consequence of hypermethylation of CpG islands is an important mechanism in the inactivation of p16INK4 tumor suppressor gene. This study is designed to clarify the significance of p16INK4 hypermethylation in 23 cases of glioblastomas (GBMs) by methylation-specific polymerase chain reaction (PCR) and p16 immunostaining. Fourteen cases (60.9%) out of 23 GBMs revealed hypermethylation on p16. p16 immunostaining revealed that 13 (93%) of these 14 hypermethylation cases showed complete loss of immunoreactivity and only one (7%) case retained immunoreactivity. Among 9 methylation-negative cases, 4 were immunonegative, which might be related to mutations or deletions other than hypermethylation. The most significant finding was that of 17 cases with immunonegativity, 13 cases (76.5%) showed hypermethylation. We reconfirmed that p16 hypermethylation may be one of the major mechanisms of tumorigenesis of GBMs and the results between the methylation specific-PCR study and p16 immunostaining had a good correlation.