CDKN2A promoter methylation enhances self-renewal of glioblastoma stem cells and confers resistance to carmustine.

BACKGROUND: Glioblastoma, a highly aggressive form of brain cancer, poses significant challenges due to its resistance to therapy and high recurrence rates. This study aimed to investigate the expression and functional implications of CDKN2A, a key tumor suppressor gene, in glioblastoma cells, building upon the existing background of knowledge in this field. METHOD: Quantitative reverse transcription PCR (qRT-PCR) analysis was performed to evaluate CDKN2A expression in U87 glioblastoma cells compared to normal human astrocytes (NHA). CDKN2A expression levels were manipulated using small interfering RNA (siRNA) and CDKN2A overexpression vector. Cell viability assays and carmustine sensitivity tests were conducted to assess the impact of CDKN2A modulation on glioblastoma cell viability and drug response. Sphere formation assays and western blot analysis were performed to investigate the role of CDKN2A in glioblastoma stem cell (GSC) self-renewal and pluripotency marker expression. Additionally, methylation-specific PCR (MSP) assays and demethylation treatment were employed to elucidate the mechanism of CDKN2A downregulation in U87 cells. RESULT: CDKN2A expression was significantly reduced in glioblastoma cells compared to NHA. CDKN2A overexpression resulted in decreased cell viability and enhanced sensitivity to carmustine treatment. CDKN2A inhibition promoted self-renewal capacity and increased pluripotency marker expression in U87 cells. CDKN2A upregulation led to elevated protein levels of p16INK4a, p14ARF, P53, and P21, which are involved in cell cycle regulation. CDKN2A downregulation in U87 cells was associated with high promoter methylation, which was reversed by treatment with a demethylating agent. CONCLUSION: Our findings demonstrate that CDKN2A downregulation in glioblastoma cells is associated with decreased cell viability, enhanced drug resistance, increased self-renewal capacity, and altered expression of pluripotency markers. The observed CDKN2A expression changes are mediated by promoter methylation. These results highlight the potential role of CDKN2A as a therapeutic target and prognostic marker in glioblastoma.

Villosol reverses 5-FU resistance in colorectal cancer by inhibiting the CDKN2A gene regulated TP53-PI3K/Akt signaling axis.

ETHNOPHARMACOLOGICAL RELEVANCE: Patrinia villosa (Juss.) (PV) is the drug of choice in traditional Chinese medicine for the treatment of colorectal cancer (CRC) and has achieved reliable efficacy in clinic. Villosol is the active ingredient in PV. However, the molecular mechanism by which Villosol reverses chemoresistance in CRC remains unclear. AIM OF THE STUDY: Analysis of the molecular mechanism by which Villosol, the active ingredient of PV, reverses CRC/5-FU resistance through modulation of the CDKN2A gene was validated by network pharmacology techniques and experiments. MATERIALS AND METHODS: We identified CDKN2A as a gene associated with 5-FU resistance through gene chip analysis. Next, we conducted a series of functional analyses in cell lines, animal samples, and xenograft models to investigate the role, clinical significance, and abnormal regulatory mechanisms of CDKN2A in 5-FU resistance in CRC. In addition, we screened and obtained a raw ingredient called Villosol, which targets CDKN2A, and investigated its pharmacological effects. RESULTS: Analysis of CRC cells and animal samples showed that the upregulation of CDKN2A expression was strongly associated with 5-FU resistance. CRC cells overexpressing CDKN2A showed reduced sensitivity to 5-FU and enhanced tumor biology in vitro. Inhibition of aberrant activation of CDKN2A enhances the expression of TP53. Mechanistically, overexpression of CDKN2A activates the PI3K/Akt pathway and induces resistance to 5-FU. Villosol inhibited CDKN2A, and CRC/5-FU cells regained sensitivity to 5-FU. Villosol effectively reverses 5-FU resistance through the CDKN2A-TP53-PI3K/Akt axis. CONCLUSION: Changes in CDKN2A gene expression can be used to predict the response of CRC patients to 5-FU therapy. Additionally, inhibiting CDKN2A activation with Villosol may present a new approach to overcoming 5-FU resistance in clinical settings.

Identification of cuproptosis-related diagnostic biomarkers in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease with clinical and pathological heterogeneity. Recent studies have identified cuproptosis as a novel cell death mechanism. However, the role of cuproptosis-related genes in the pathogenesis of IPF is still unclear. Two IPF datasets of the Gene Expression Omnibus database were studied. Mann-Whitney U test, correlation analysis, functional enrichment analyses, single-sample gene set enrichment analysis, CIBERSORT, unsupervised clustering, weighted gene co-expression network analysis, and receiver operating characteristic curve analysis were used to conduct our research. The dysregulated cuproptosis-related genes and immune responses were identified between IPF patients and controls. Two cuproptosis-related molecular clusters were established in IPF, the high immune score group (C1) and the low immune score group (C2). Significant heterogeneity in immunity between clusters was revealed by functional analyses results. The module genes with the strongest correlation to the 2 clusters were identified by weighted gene co-expression network analysis results. Seven hub genes were found using the Cytoscape software. Ultimately, 2 validated diagnostic biomarkers of IPF, CDKN2A and NEDD4, were obtained. Subsequently, the results were validated in GSE47460. Our investigation illustrates that CDKN2A and NEDD4 may be valid biomarkers that were useful for IPF diagnosis and copper-related clustering.

Assessment and clinicopathological correlation of p16 expression in cervical squamous cell carcinoma of Indian population: Diagnostic implications.

BACKGROUND: Our aim was to assess the p16 expression in normal cervical epithelium and cervical lesions and how it correlated with HPV oncoprotein E7 and other etiological parameters of cervical cancer. METHODS: For this purpose, we analyzed protein expression of p16 and E7 oncoprotein in total 20 normal cervical epithelium tissue (as control) and 62 cervical lesions. Next, the result was correlated with different clinico-pathological parameters. RESULTS: Out of 62 cases of cervical lesions, we found around 75%-100% of the cervical lesion samples exhibited E7 nuclear protein expression, whereas around 33.33%-75% samples were p16 positive. On the other hand, p16 expression showed strong association with E7 oncoprotein and other clinico-pathological parameters (like high parity, early age of sextual debut) in the same set of samples of our study. CONCLUSION: We concluded that overexpression of p16 is very practical and can be readily implemented in most diagnostic pathology laboratories.

Expressão imuno-histoquímica dos biomarcadores p16 e Ki-67 na lesão intraepitelial cervical de alto grau: revisão de estudos / Immunohistochemical expression of biomarkers p16 and Ki-67 in high-grade cervical intraepithelial lesion: review of studies

O câncer do colo do útero é o quarto tumor mais comum entre mulheres no mundo e o terceiro no Brasil. A detecção precoce e a identificação das lesões cervicais são essenciais no rastreamento do câncer cervical. Nos últimos anos, vários marcadores têm sido apresentados como possíveis candidatos para a triagem eficiente de exames citológicos com anormalidades das células epiteliais. O objetivo deste trabalho é analisar a correlação com a expressão imuno-histoquimica dos biomarcadores p16 e Ki-67 com lesão intraepitelial cervical de alto grau na detecção molecular DNA/HPV de alto risco. A metodologia de pesquisa empregada é uma revisão sistemática, realizada por meio de buscas nas bases de dados eletrônica Literatura Latino-Americana em Ciência e Saúde (LILACS), Scientific Electronic Library Online (SCIELO), National Library of Medicine (MEDLINE) de artigos publicados no período de 2005 a 2019 nos idiomas português, inglês e espanhol. Concluiu-se que o uso das proteínas p16 e Ki67 auxilia na identificação das mudanças que acontecem durante a progressão da lesão cervical, aprimorando os métodos de rastreio atuais. O gene p53, a pRb e ciclinas também têm um papel crítico na carcinogênese e, desta maneira, também têm sido indicados para entrar nos painéis de estudo.

Cervical cancer is the fourth most common tumor among women in the world and the third in Brazil. Early detection and identification of cervical lesions are essential in screening for cervical cancer. In recent years, several markers have been presented as possible candidates for efficient screening of cytological exams with abnormalities of epithelial cells. The objective of this work is to analyze the correlation with the immunohistochemical expression of the biomarkers p16 and ki-67 with high-grade cervical intraepithelial lesion in high-risk DNA / HPV molecular detection. The research methodology employed is a systematic review, carried out by searching the electronic databases Latin American Literature in Science and Health (LILACS), Scientific Electronic Library Online (SCIELO), National Library of Medicine (MEDLINE) of published articles from 2005 to 2019 in Portuguese, English and Spanish. It was concluded that the use of proteins p16 and Ki67, help to identify the changes that happen during the progression of the cervical lesion, improving the current screening methods. The p53 gene, the retinoblastoma protein ­ pRb and cyclins also plays a critical role in carcinogenesis and thus, they have also been indicated to enter the study panels.

Metilación de genes supresores tumorales en pacientes venezolanos con cáncer colorrectal: relación con estadio clínico de la enfermedad / Relationship of Methylation of Tumor Suppressor Genes with Clinical Stage of Colorectal Cancer in Venezuelan Patients

Resumen El cáncer colorrectal es una enfermedad heterogénea, en cuya aparición se involucran factores hereditarios y ambientales. En las formas heredadas existen genes responsables de incrementar el desarrollo tumoral en los portadores, y se consideran a los factores medioambientales como responsables de gran parte de las formas esporádicas. El objetivo de este estudio fue analizar el estado de metilación de 5 genes implicados en la carcinogénesis colorrectal y su relación con los distintos estadios clínicos de estos tumores. Por una parte, nuestro análisis reveló que el estado de metilación de los promotores de los genes HMLH1 (human mut homologue 1), APC (adenomatous poliposis coli), P15, P16 y CDH1, considerados como unas de las alteraciones más tempranas en este proceso; fluctuaron entre 13,3 % para hMLH1 y 56,6 % para APC. También reveló que la inactivación epigenética de los genes APC y P16 podrían ser responsables de la aparición y de la progresión de los tumores ya que se encontraron en pacientes con estadio II. Por otra parte, los genes APC y p15 resultaron estar mutados en todas las etapas de la carcinogénesis, por lo que se involucrarían en todos los procesos tanto de inicio como de invasión y metástasis. Por último, nuestros resultados apoyan la utilización de la identificación de la metilación de los genes supresores ya que se están identificando dianas epigenéticas para el desarrollo de nuevos tratamientos de quimioterapia y está emergiendo como una estrategia con gran potencial dado que, en principio, las alteraciones epigenéticas son potencialmente reversibles.

Abstract Colorectal cancer is a heterogeneous disease which involves hereditary and environmental factors. The inherited forms have genes which are responsible for increasing the tumor development in carriers. Environmental factors are considered responsible for many sporadic forms. The objective of this study was to analyze the methylation status of five genes involved in colorectal carcinogenesis and their relationships with the various clinical stages of these tumors. Our analysis revealed that the methylation status of the promoters of genes HMLH1, APC, P15, P16 and CDH1, considered to be among the earliest alterations in this process, ranged from 13.3% for HMLH1 to 56.6% for APC. In addition, epigenetic inactivation of APC and P16 genes could be responsible for the appearance and progression of tumors since inactivation was found in stage II patients. On the other hand, the APC and p15 gene were mutated in all stages of carcinogenesis, so they could be involved throughout the processes of initiation, invasion and metastasis. Finally, our results support using identification of methylation of suppressor genes since they identify epigenetic targets for development of new chemotherapy treatments. This is emerging as a strategy with great potential since epigenetic alterations are, in principle, potentially reversible.

Evaluation of p16ink4a expression and presence of HPV-16 DNA by real time PCR in patients with oral leukoplakia / Avaliação da expressão da p16Ink4a e a presença do DNA do HPV-16 pela Real time PCR em pacientes com leucoplasia bucal

Objetivo: Avaliar a expressão do p16Ink4a por imunohistoquímica e a presença do HPV16 pela Real time PCR em tecido fresco, plasma e saliva de pacientes com leucoplasia bucal (LB) e hiperplasia fibrosa inflamatória (HFI). Material e métodos: Foram incluídos 67 pacientes com o diagnóstico de LB e 44 pacientes com diagnóstico de HFI no estudo. Foram coletados dados sociodemográficos, clinicopatológicos, amostras de tecido fresco, sangue e saliva, que foram armazenados em um freezer a -80o C para realização de análise molecular. Também foi utilizado o tecido parafinizado para realização da imunohistoquímica para a p16Ink4a. As amostras de materiais biológicos obtidos dos pacientes foram submetidas à detecção do DNA do HPV-16 pela Real time PCR. O tecido parafinizado dos mesmos pacientes foram utilizados para avaliar a expressão da p16Ink4a pela imunohistoquímica. Resultados: Dos 67 pacientes incluídos de LB no estudo, 55,2% eram do sexo masculino com uma média de idade de 57,1 anos. Os pacientes idosos (>45 anos) compuseram 86,6% da amostra. As localizações anatômicas mais acometidas por LB foram a mucosa jugal (35,8%) e língua (20,9%). Sobre o tabagismo, 71,8% dos pacientes eram fumantes, onde a maioria (47,8%) foi classificada como tabagista leve. Em relação ao consumo de álcool, 47,4% eram alcoolistas, sendo a sua maioria classificada como alcoolista leve (59,3%). O grupo HFI foi composto por 54,5% pacientes do sexo masculino com uma média de idade de 57,3 anos. 90,9% dos pacientes eram idosos (>45 anos). A ocorrência das lesões foram em mucosa jugal (31,8%) e rebordo alveolar (25%). A expressão para p16Ink4a na LB foi fraca (41,8%) e para o grupo HFI, majoritariamente a expressão foi forte (68,2%). Real time PCR não detectou HPV-16 em nenhumas das amostras analisadas. Conclusão: Os achados em nosso estudo mostraram que a detecção de HPV de alto risco em tecido fresco, plasma e saliva para LB e HFI não se correlacionaram com a superexpressão da p16Ink4a(AU)

Objective: To evaluate the expression of p16Ink4a by immunohistochemistry and the presence of HPV-16 by Real time PCR in fresh tissue, blood plasma, and saliva of patients with oral leukoplakia (OL) and inflammatory fibrous hyperplasia (IFH). Material and methods: Sixty-seven patients with the diagnosis of OL and 44 patients with the diagnosis of IFH were included in the study. Sociodemographic, clinicopathological, fresh tissue, blood, and saliva samples were collected and stored at - 80o C for molecular analysis. Paraffinized-embedded tissue was also used to perform the immunohistochemistry for p16Ink4a. Samples of biological material obtained from the patients were submitted to HPV-16 DNA detection by real time PCR, both with specific probes. Paraffinized-embedded tissue from the same patients were used to evaluate the expression of p16ink4a by immunohistochemistry. Results: Out of the 67 included OL patients, 55.2% were male with a mean age of 57.1 years. Elderly patients (> 45 years) comprised 86.6% of the sample. The prevalence of lesions was highest in the buccal mucosa (35.8%) followed by the mobile tongue (20.9%). 71.8% were smokers and the majority (47.8%) was classified as light smoker. Regarding alcohol consumption, 47.4% were alcoholics, most of whom were classified as light alcoholics (59.3%). The IFH group was composed of 54.5% of male patients with a mean age of 57.3 years. 90.9% of the sample were elderly patients (> 45 years). The highest occurrence of the lesions was in buccal mucosa (31.8%) and alveolar ridge (25%). The expression for p16Ink4a in LB was mostly weak (41.8%) and for the IFH group, the expression was mostly strong (68.2%). There was no positivity in any of the samples for HPV-16 by real time PCR. Conclusion: Our findings showed the HR-HPV detection in fresh tissue, plasma blood and saliva for OL and IFH does not correlate with p16Ink4a immunoexpression in paraffinized-embedded tissue(AU)

Knockout of p16INK4a promotes aggregative growth of dermal papilla cells

Summary Objective: Dermal papilla cells (DPCs) are located in the hair follicles and play an important role in hair growth. These cells have the ability to induce hair follicle formation when they display aggregative behavior. DPCs derived from the androgenetic alopecia (AGA) area undergo premature senescence in vitro, associated with p16INK4a expression. The aim of the current study was to investigate the expression of p16INK4a in aggregative and non-aggregative DPCs and the effect of p16INK4a down-regulation in these cells by adenovirus-mediated RNA interference (RNAi). Method: DPCs were isolated and cultured from healthy human scalp. p16INK4a gene and protein were detected in aggregative and non-aggregative cells. Expression of p16INK4a in DPCs was silenced by infection with rAd5-CDKN1A-1p2shRNA. Cell fate was monitored after infection. The growth of cells was measured by MTT assay. Cell cycle was evaluated by flow cytometry (FCM). Results: DPCs were isolated by digestion and showed aggregative behavior for six passages. The expression of p16INK4a showed a clear upward trend in non-aggregative cells when compared with aggregative group. p16INK4a expression was silenced by rAd5-CDKN1A-1p2shRNA (p<0.05). The p16INK4a-silenced cells grew more rapidly and exhibited a trend towards aggregative growth. There was an increase in the proportion of cells in G1 phase, while those in S phase were reduced after p16INK4a gene silencing (p<0.05). Conclusion: Our results suggest that p16INK4a plays an important role in the premature senescence and aggregative behavior of DPCs. These observations can lead to novel therapeutic strategies for treatment of AGA.

p16 Hypermethylation and KRAS Mutation Are Independent Predictors of Cetuximab Plus FOLFIRI Chemotherapy in Patients with Metastatic Colorectal Cancer / Journal of the Korean Cancer Association, 대한암학회지

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, MINT31, and hMLH1) in DNA extracted from formalin-fixed paraffin-embedded specimens. Logistic regression and Cox regression were performed for analysis of the relation between methylation status of CpG island methylator phenotype (CIMP) markers including p16 and clinical outcome. RESULTS: Hypermethylation of the p16 gene was detected in 14 of 49 patients (28.6%) and showed significant association with KRAS mutation (Fisher exact, p=0.01) and CIMP positivity (Fisher exact, p=0.002). Patients with p16-unmethylated tumors had significantly longer time to progression (TTP; median, 9.0 months vs. 3.5 months; log-rank, p=0.001) and overall survival (median, 44.9 months vs. 16.4 months; log-rank, p=0.008) than those with p16-methylated tumors. Patients with both KRAS and p16 aberrancy (n=6) had markedly shortened TTP (median, 2.8 months) compared to those with either KRAS or p16 aberrancy (n=11; median, 8.6 months; p=0.021) or those with neither (n=32; median, 9.0 months; p < 0.0001). In multivariate analysis, KRAS mutation and p16 methylation showed independent association with shorter TTP (KRAS mutation: hazard ratio [HR], 3.21; p=0.017; p16 methylation: HR, 2.97; p=0.027). CONCLUSION: Hypermethylation of p16 was predictive of clinical outcome in metastatic CRC patients treated with cetuximab and FOLFIRI, irrespective of KRAS mutation.

Genetic Basis of Gastric Cancer / 中国医学科学杂志(英文版)

Gastric cancer is the result of multiple risk factors, including environmental factors, genetic factors and the interaction between them. The environmental factors mainly include dietary, Helicobacter pylori infection and family history of gastric cancer. Genetic factors mainly refer to the susceptible genes that cause epigenetic alterations in oncogenes, tumor suppress genes, cell cycle regulators, DNA repair genes and signaling molecules. This paper summarizes the susceptible genes of gastric cancer and explores the genetic basis of it.

Detection of p16 by fluorescence in-situ hybridization and immunohistochemistry in malignant mesothelioma / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the role of p16 gene mutation status as detected by fluorescence in-situ hybridization (FISH) and p16 protein expression as detected by immunohistochemistry in differential diagnosis of malignant mesothelioma and benign mesothelial hyperplasia.</p><p><b>METHODS</b>p16 gene mutation status and protein expression were detected by FISH and immunohistochemistry respectively in 55 cases of pleural malignant mesothelioma and 30 cases of benign mesothelial hyperplasia.</p><p><b>RESULTS</b>FISH study showed that the rate of p16 deletion in malignant mesothelioma (81.8%,45/55) was higher than that in benign mesothelial hyperplasia (3.3%,1/30). The difference was statistically significant (P<0.05). Immunohistochemical study showed that the rate of p16 protein expression in malignant mesothelioma (23.6%) was lower than that in benign mesothelial hyperplasia (76.7%). The difference was also statistically significant. The sensitivity and specificity of FISH in distinguishing between mesothelioma and reactive mesothelial hyperplasia were higher than those of immunohistochemistry.</p><p><b>CONCLUSIONS</b>In contrast to reactive mesothelial hyperplasia, p16 gene is deleted and p16 protein is not expressed in malignant mesothelioma. The sensitivity and specificity of FISH are higher than those of immunohistochemistry in the distinction.</p>

Clinical features and expressions of p16, p53 protein of human papillomavirus-related tonsillar carcinoma / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To analyze the clinical characteristics, prognosis and molecular biological changes of tonsillar squamous cell carcinoma (TSCC).</p><p><b>METHODS</b>Retrospective analysis of 61 TSCC cases treated from January 1999 to December 2012. Demographic data and clinical charts, including histologic grade of tumor, treatment and outcome of the patients, were reviewed.Human papillomavirus (HPV)-DNA were detected using SPF10-DNA enzyme immunoassay and LiPA genotyping method. Expressions of p16 and p53 proteins were examinated by immunohistochemistry. Survival rate was calculated with SPSS 19.0 software using the Kaplan-Meier method.</p><p><b>RESULTS</b>There were 55 males and 6 females, with a median age of 57 years. Of the 61 TSCC, 21 were with well differentiation, 19 with moderate differentiation and 21 with poor differentiation, including 7 patients at stage II, 10 at stage III and 44 at stage IV. HPV-positive rate of TSCC was 29.5% (18/61) and high-risk HPV-16 subtype accounted for 72.2% (13/18). The percentage of famel patients in HPV-positive TSCC was higher than HPV-negative TSCC (22.2% vs 4.7%).HPV-positive TSCC was more common in non-smoking patients (50.0% vs 79.1%, χ(2) = 5, 155, P = 0.023) and non-drinking patients (27.8% vs 51.2%, χ(2) = 4.346, P = 0.037). HPV-positive TSCC mostly presented with high expression of p16 protein (88.9% vs 16.3%, χ(2) = 28.481, P = 0.000), and low expression of p53 protein (72.7% vs 46.5%, χ(2) = 5.028, P = 0.025). The prognosis of patients with HPV-associated TSCC was significantly better than non-HPV-associated TSCC, and The 3-year and 5-year overall survival rates of patients with HPV-positive TSCC were higher than those of patients with HPV-negative TSCC (87.7% vs 49.5% and 78.9% vs 33.0%, respectively).</p><p><b>CONCLUSION</b>HPV-associated TSCC had unique clinicopathological and molecular biological features, showing better prognosis compared to HPV-negative TSCC.</p>

Prebiotics prevent the appearance of aberrant crypt foci (ACF) in the colon of Balb/C mice for increasing the gene expression of p16 protein / Los prebióticos previenen la aparición de focos de cripta aberrantes (FCA) en el colon de ratones Balb/C para aumentar la expresión génica de la proteína P16

Studies have shown fibers to be effective in reducing the appearance of aberrant crypt foci (ACF) in rodents. Objective: The goal of this study was to investigate the preventive effects of fructooligosaccharide (FOS) and inulin prebiotics on the appearance of ACF in mice. Materials and Methods: The techniques used were: RT-PCR to evaluate the gene expression of p16, p21, p54, cyclin D1 and cyclin E in the distal colon; the quantification of Number of aberrant crypt foci (ACF) and measurement of catalase activity in the liver and distal colon. The animals were divided into five treatments (n=8); C-: AIN93M diet without fibers + DMH (1,2-dimethylhydrazine); INL: AIN93M diet with inulin; INLCA: AIN93M diet with inulin + DMH; FOS: AIN93M diet with FOS; FOSCA: AIN93M diet with FOS + DMH, during 15 weeks. Results: Inulin prevented the appearance of ACF in the proximal, middle and distal colon, compared to the control without fibers. In the middle and distal colon, FOS was also effective in preventing the incidence of ACF. This effectiveness may be attributed to the increased gene expression of p16 following FOS treatment. Both prebiotics also decreased catalase activity in the distal colon, thus suggesting an antioxidant effect. Conclusion: These results suggesting an antioxidant effect prebiotics that may be attributed to the increased gene expression of p16 (AU)

Existen estudios que demuestran la eficacia de fibras para reducir la aparición de focos de cripta aberrantes (FCA) en roedores. Objetivo: El objetivo de este estudio consistió en investigar los efectos preventivos de los fructooligosacáridos (FOS) y el prebiótico inulina sobre la aparición de FCA en ratones. Materiales y métodos: Las técnicas empleadas fueron: RT-PCR para evaluar la expresión génica de p16, p21, p54, ciclina D1 y ciclina E en el colon distal; la cuantificación del Número de FCA y la medición de la actividad de la catalasa en el hígado y el colon distal. Los animales fueron divididos en cinco tratamientos (n=8); C-: dieta AIN93M sin fibra + DMH (1.2-dimetilhidrazina); INL: dieta AIN93M con inulina; INLCA: dieta AIN93M con inulina + DMH; FOS: dieta ANIN93M con FOS; FOSCA: dieta AIN93M con FOS + DMH, durante 15 semanas. Resultados: La inulina previno la aparición de FCA en el colon proximal, medio y distal, comparado con el control sin fibras. En el colon medio y distal, FOS también fue efectiva para prevenir la incidencia de FCA. Esta efectividad podría ser atribuida al aumento de la expresión génica de p16 tras el tratamiento con FOS. Ambos prebióticos también disminuyeron la actividad de la catalasa en el colon distal, lo que sugiere un efecto antioxidante. Conclusión: Estos resultados sugieren un efecto antioxidante de los prebióticos que podría atribuirse a un aumento de la expresión génica de p16 (AU)

Diagnostic value of p16 methylation for malignant pleural effusion a meta-analysis / Valor diagnóstico de la metilación p16 en el derrame pleural maligno un meta-análisis

OBJECTIVE: To evaluate the overall diagnostic performance of the p16 methylation for diagnosing malignant pleural effusion (MPE). METHODS: All published literature in English and Chinese were reviewed. Sensitivity, specificity, likelihood ratio and diagnostic odds ratio (DOR) were pooled by using random-effects model or fixed-effects model. Summary receiver operating characteristic (SROC) curve was used to evaluate the overall diagnostic value. RESULTS: Six studies were included with a total of 378 cases. The sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and DOR of p16 methylation in the diagnosis of MPE were 0.41 [95% confidence interval (CI) 0.35, 0.48], 0.97 [95% CI 0.93, 0.99], 9.57 [95% CI 4.53, 20.20], 0.61 [95% CI 0.45, 0.82] and 19.82 [95% CI 8.35, 47.04], respectively. The area under the curve (AUC) was 0.864. CONCLUSION: Pleural p16 methylation test plays a useful role in the diagnosis of MPE.

OBJETIVO: Evaluar el rendimiento diagnóstico general de la metilación p16 para el diagnóstico del derrame pleural maligno (DPM). MÉTODOS: Se revisó toda la literatura publicada en inglés y chino. La sensibilidad, especificidad, razón de verosimilitud, y el odds-ratio diagnóstico (DOR) fueron agrupados mediante el modelo de efectos aleatorios o el modelo de efectos. La curva de las características operativas de resumen del receptor (SROC) fue usada para evaluar el valor diagnóstico general. RESULTADOS: Se incluyeron seis estudios con un total de 378 casos. La sensibilidad, especificidad, razón de verosimilitud positiva (PLR), razón de verosimilitud negativa (NLR) y el DOR de la metilación p16 en el diagnóstico de DPM, fueron 0.41 [95% intervalo de confianza (IC) 0.35 0.48], 0.97 [95% IC 0.93, 0.99], 9.57 [95% IC 4.53, 20.20], [95% IC 0.45, 0.82] 0.61 y 19.82 [95% IC 8.35, 47.04], respectivamente. El área bajo la curva (AUC) fue 0.864. CONCLUSIÓN: La prueba de metilación p16 pleural desempeña un papel útil en el diagnóstico del DPM.

Adenocarcinomas nasosinusales tipo intestinal. Perfil inmunohistoquímico de 66 casos / Intestinal-type sinonasal adenocarcinomas. Immunohistochemical profile of 66 cases

Introducción y objetivos: Los adenocarcinomas nasosinusales tipo intestinal son tumores epiteliales malignos, que suponen el 8-25% de los tumores malignos nasosinusales. Se relacionan con la exposición al polvo de la madera. Se subdividen histológicamente en papilares, colónicos, sólidos y mucinosos. Realizamos un estudio patológico e inmunohistoquímico con el fin de establecer características con significado pronóstico, diagnóstico e incluso terapéutico, así como comparar con estudios previos. Métodos: Estudiamos 66 muestras tumorales mediante matrices tisulares. Realizamos tinciones inmunohistoquímicas para p53, p16, beta-catenina, E-cadherina, receptor del factor de crecimiento epidérmico (EGFR), receptor 2 de factor de crecimiento epidérmico humano (HER2/neu) y ciclooxigenasa 2 (COX-2). Resultados: Un 63% de los casos son positivos para p53, el 37% para beta-catenina nuclear, el 100% para E-cadherina, el 98% para beta-catenina membranosa, el 7% para EGFR, el 8% para HER2/neu, el 52% para COX-2 y el 59% pierden la expresión de p16. Conclusiones: La invasión intracraneal es el factor clínico pronóstico más importante. Los tumores de tipo sólido y mucinoso son los que muestran un comportamiento más agresivo, siendo los mucinosos los que mayor invasión intracraneal muestran. No existen diferencias inmunohistoquímicas entre los distintos subtipos histológicos, únicamente la tinción débil para E-cadherina y beta-catenina, más frecuente en los de tipo mucinoso. El EGFR, HER2/neu y COX-2 muestran una positividad menos frecuente que en series previas. La positividad para p16 se asocia a una menor supervivencia y mayor frecuencia de enfermedad metastásica.Palabras clave Adenocarcinoma nasosinusal. Carcinoma nasosinusal. Inmunohistoquímica. p53. p16. beta-catenina. E-cadherina. Receptor del factor de crecimiento epidérmico. Receptor 2 de factor de crecimiento epidérmico humano. Cyclooxigenasa-2 (AU)

Introduction and objectives: Intestinal-type sinonasal adenocarcinomas are malignant epithelial tumours. Around 8-25% of all sinonasal malignant tumours are intestinal-type adenocarcinomas, which are related to wood dust exposure. Four histological subtypes have been described: papillary, colonic, solid and mucinous. We performed a pathological and immunohistochemical study in order to describe characteristics with prognostic, diagnostic and therapeutic value, and also to compare our results with previous studies. Methods: Sixty six tumour samples were analysed and protein expression of p53, p16, E-cadherin, beta-catenin, epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2/neu) and cyclooxygenase-2 (COX-2) was performed by tissue microarray blocks. Results: The 63% of cases were p53 positive; 37% showed nuclear staining with beta-catenin and 100% with E-cadherin, while 98% showed membrane staining with beta-catenin, 7% with EGFR, 8% with HER2/neu and 52% with COX-2; and 59% of the cases lost p16 expression. Conclusions: Intracranial invasion was the worst prognostic associated event. Solid and mucinous tumours were the most aggressive histological subtypes. Intracranial invasion was more frequent in mucinous subtype tumours. Immunohistochemical results were similar in all tumour subtypes, except for mucinous tumours, which showed weak expression of E-cadherin and beta-catenin. Comparing with previous studies, we found a lower expression of EGFR, HER2/neu and COX-2. The p16 expression was associated with worse survival and metastatic disease (AU)

Primary Squamous Cell Carcinoma of the Upper Genital Tract: Utility of p16INK4a Expression and HPV DNA Status in its Differential Diagnosis from Extended Cervical Squamous Cell Carcinoma

BACKGROUND: Primary squamous cell carcinoma (SCC) of the upper genital tract, including the endometrium, fallopian tubes, and ovaries, is extremely rare. It must be distinguished from the mucosal extension of primary cervical SCC because determination of the primary tumor site is important for tumor staging. However, patients with SCC of the fallopian tubes or ovarian surface have often undergone prior hysterectomy with inadequate examination of the cervix, making it difficult to determine the primary site. METHODS: We compared histologic findings, p16INK4a expression, and human papillomavirus (HPV) DNA status in four patients with primary SCC of the upper genital tract and five patients with primary cervical SCC extending to the mucosa of the upper genital tract. RESULTS: All five SCCs of cervical origin showed strong expression of p16INK4a, whereas all four SCCs of the upper genital tract were negative, although one showed weak focal staining. Three of the five cervical SCCs were positive for HPV16 DNA, whereas all four primary SCCs of the upper genital tract were negative for HPV DNA. CONCLUSIONS: Although a thorough histological examination is important, immunonegativity for p16INK4a and negative for HPV DNA may be useful adjuncts in determining primary SCCs of the upper genital tract.

Hepatitis B virus X promotes HepG2 cell cycle progression and growth via downregulation expression of p16 protein / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the effects and related mechanisms of hepatitis B virus X (HBx) protein on cell cycle and growth in hepatocellular carcinoma.</p><p><b>METHODS</b>A human hepatocyte HepG2 cell line stably expressing a green fluorescent protein (GFP)-tagged HBx (HepG2/GFP-HBx cells) was used for the experiment, and HepG2 parental and HepG2/GFP cells was used as the controls. Effect of HBx on cell growth was evaluated by the MTT cell proliferation assay and on cell cycle progression by flow cytometry analysis of cells with or without treatment with 5-aza-2'-deoxycytidine (5-Aza-CdR; 5 pmol/L). Effect of HBx expression on promoter methylation status of the p16INK4A tumor-suppressor gene was detected by methylation-specific polymerase chain reaction and on p16 protein level was analyzed with western blotting.</p><p><b>RESULTS</b>The HepG2/GFP-HBx cells showed significantly higher cell proliferation at 72 hrs of culture (3.225+/-0.038 A490) than either control (HepG2: 2.012+/-0.022 A490, t = -46.86, P less than 0.001; HepG2/GFP: 2.038+/-0.029 A490, t = 42.51, P less than 0.001). The HepG2/GFP-HBx cells also showed significantly lower proportion of cells in the G0/G1 phase (16.45%+/-0.45%) than either control (HepG2: 44.81%+/-1.36%, t = -34.202, P less than 0.001; HepG2/GFP: 42.76%+/-1.58%, t = -28.88, P less than 0.001). However, 5-Aza-CdR treatment did lead to a significant amount of HepG2/GFP-HBx cells being arrested in the G0/G1 phase (33.25%+/-0.79%, t = 31.85, P less than 0.001). The p16INK4A promoter was methylated in the HepG2/GFP-HBx cells, and became demethylation after treatment with 5-Aza-CdR. However, no methylation of p16INK4A promoter was observed in both HepG2 and HepG2/GFP cells. The p16 protein level was significantly lower in the HepG2/GFP-HBx (vs. HepG2 and HepG2/GFP cells) and this level increased after treatment with 5-Aza-CdR.</p><p><b>CONCLUSION</b>HBx protein promotes hepatocellular carcinoma cell cycle progression and growth by shortening the G0/G1 phase, and the underlying mechanism may involve inducing p16INK4A promoter methylation and downregulating p16 protein expression.</p>

Disappearance of Serum Methylated p16 Indicates Longer Survival in Patients with Gastric Cancer

PURPOSE: The aim of this study was to assess clinical correlations with postoperative alteration of p16 DNA methylation, and to clarify whether postoperative changes in the serum DNA methylation status of p16 could be used as a reliable prognostic factor for gastric cancer. MATERIALS AND METHODS: Fifty-three consecutive gastric adenocarcinoma patients who underwent gastric resection (Chung-Ang University Hospital, Seoul, Korea) were included. DNA methylation of p16 was evaluated by methylation-specific polymerase chain reaction using serum DNA preoperatively and at the 10th postoperative day. The correlation between changes in methylation status and patients' prognosis was analyzed. RESULTS: p16 was methylated in 79.2% of preoperative serum DNA and in 54.7% of postoperative serum DNA, respectively. Methylation in p16 disappeared more frequently in patients who underwent standard D2 lymphadenectomy compared to those who underwent modified D1+ lymphadenectomy (P=0.016). Whereas methylation of preoperative serum DNA was not correlated with survival, patients with postoperative disappearance of p16 methylation showed longer survival than those without postoperative disappearance of p16 methylation in the patients who had gastric cancer with lymph node metastasis (P=0.042). CONCLUSIONS: Postoperative disappearance of p16 methylation could be an available prognostic factor for node-positive gastric cancer.

Comparison of clinical implications of p16 deletion in childhood and adult B-lineage acute lymphoblastic leukemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate and compare the clinical implications of p16 deletion in childhood and adult B-lineage acute lymphoblastic leukemia (B-ALL).</p><p><b>METHODS</b>A total of 129 cases of de novo childhood (73 cases) and adult (56 cases) B-ALL were examined genetically and immunologically using G-banding techniqhe, interphase fluorescence in situ hybridization (I-FISH) and immunophenotyping by flow cytometry, and their clinical data were retrospectively analyzed.</p><p><b>RESULTS</b>Of 73 childhood cases, the prevalences of homozygous deletion, hemizygous deletion and no deletion of p16 were 24.7% (18 cases), 6.8% (5 cases) and 68.5% (50 cases) respectively, and of 56 adult cases, the incidences as of 14.3% (8 cases), 8.9% (5 cases) and 76.8% (43 cases) respectively. The incidence of p16 deletion between the two groups had no significant difference (P = 0.338). In both groups, patients with or without p16 deletion had no significant difference in terms of white blood cells (WBC) count at diagnosis, BM blast percentage, chromosome karyotype, extra-infiltration and CR1 rate. Of note, there were 2 cases, each in childhood and adult, showed no deletion at the time of diagnosis, their p16 deletions occurred at relapse. The deletion of p16 was associated with poor overall survival and event-free survival (EFS) in both childhood and adults. According to the standard of NCI risk stratification, we divided patients of two groups into standard and high risk category respectively, and performed further analysis. The significance of different risk category in children and adults was disparity. The overall survival (OS) rates of deletion and no deletion of p16 were 45.3% and 79.8% (P = 0.006) in children, and 7.7% and 22.6% (P = 0.002) in adults, respectively. EFS rates of deletion and no deletion of p16 were 33.5% and 58.1% (P = 0.008) in children, and 0 and 10.9% (P < 0.01) in adults, respectively. Of the standard risk category in children, OS rates of deletion and no deletion of p16 were 46.8% and 89.3% (P = 0.015) respectively, and EFS rates of deletion and no deletion of p16 as of 40.9% and 82.1% (P = 0.007) respectively. Of the high risk category in children, OS rates of deletion and no deletion of p16 were 41.7% and 67.4% (P = 0.193) respectively, and EFS rates of deletion and no deletion of p16 were 25.0% and 25.6% (P = 0.305) respectively. Of the standard risk category in adults, OS rates of deletion and no deletion of p16 were 20.0% and 46.9% (P = 0.092) respectively, and EFS rates of deletion and no deletion of p16 were 0 and 25.0% (P = 0.062) respectively. Of the high risk category in adults, OS rates of deletion and no deletion of p16 were 0 and 12.4% (P < 0.001) respectively, and EFS rate of deletion and no deletion of p16 was 0 and 4.8%(P < 0.001), respectively.</p><p><b>CONCLUSION</b>This study indicated that deletion of p16 was associated with poor prognosis in both childhood and adult B-ALL, which highlighted an important significance to define the status of p16 in both childhood and adult B-ALL for predicting prognosis and guiding clinical intervention.</p>