Perspectives for cancer immunotherapy mediated by p19Arf plus interferon-beta gene transfer

While cancer immunotherapy has gained much deserved attention in recent years, many areas regarding the optimization of such modalities remain unexplored, including the development of novel approaches and the strategic combination of therapies that target multiple aspects of the cancer-immunity cycle. Our own work involves the use of gene transfer technology to promote cell death and immune stimulation. Such immunogenic cell death, mediated by the combined transfer of the alternate reading frame (p14ARF in humans and p19Arf in mice) and the interferon-β cDNA in our case, was shown to promote an antitumor immune response in mouse models of melanoma and lung carcinoma. With these encouraging results, we are now setting out on the road toward translational and preclinical development of our novel immunotherapeutic approach. Here, we outline the perspectives and challenges that we face, including the use of human tumor and immune cells to verify the response seen in mouse models and the incorporation of clinically relevant models, such as patient-derived xenografts and spontaneous tumors in animals. In addition, we seek to combine our immunotherapeutic approach with other treatments, such as chemotherapy or checkpoint blockade, with the goal of reducing dosage and increasing efficacy. The success of any translational research requires the cooperation of a multidisciplinary team of professionals involved in laboratory and clinical research, a relationship that is fostered at the Cancer Institute of Sao Paulo.

Effect of gene silencing of Bmi-1 on proliferation regulation of CD44+ nasopharyngeal carcinoma cancer stem-like cells / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate the effect of gene silencing of Bmi-1 on proliferation regulation of CD44+ nasopharyngeal carcinoma cancer stem-like cells (CSC-LCs).@*METHOD@#The sequence-specific short hairpin RNA lentivirus targeting at human Bmi-1 gene (LV-Bmi-1shRNA) was constructed and was used to infect CD44+ nasopharyngeal carcinoma cells which were sorted by flow cytometry. A lentiviral which included a random sequence was also designed to serve as a negative control. We employed fluorescence microscope and flow cytometry to detect infection efficiency; real-time PCR was used to detect Bmi-1 and its downstream gene while each protein expression level was confirmed by western blotting protocol; CCK-8 proliferation assay was applied to measure proliferation capacity; tumor spheroid assay was used to evaluate the self-renewal capacity. Colony formation assay was used to measure cell colony formation capability; flow cytometry analyzed cell cycle distribution.@*RESULT@#The constructed LV-Bmi-1shRNA successfully infected into the CD44+ nasopharyngeal carcinoma cells. The infection efficiency could reach above 95%; LV-Bmi-lshRNA effectively inhibited Bmi-1 mRNA and protein expression, while the downstream gene p16INK4a and p14ARF mRNA as well as protein expression level were upregulated (P < 0.05). Notablely, the proliferation, colony formation, self-renewal capabilities of the experimental group decreased significantly (P < 0.05). In addition, the cell cycle arrested at the G0-G1 phase.@*CONCLUSION@#Gene silencing of Bmi-1 inhibited the proliferation, colony formation and self-renewal capabilities of the CD44+ nasopharyngeal carcinoma CSC-LCs, inhibited the cell cycle processes, which may mediate through Bmi1-p16INK4a/p14ARF-p53 pathway. Our experimental results indicated that Bmi-1 gene may play an important role in the maintenance of the stem cell-like characteristics of CD44+ nasopharyngeal carcinoma cells. Bmi-1 gene may be a potential new target for the treatment of nasopharyng al carcinoma in the future.

Effect of up-regulated expression of tumor suppressor gene p14(ARF) on apoptosis of chronic myeloid leukemia cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of up-regulated expression of tumor suppressor gene p14(ARF) on apoptosis of chronic myeloid leukemia (CML) cells and its interaction with imatinib.</p><p><b>METHODS</b>Tumor suppressor gene p14(ARF) was transduced into K562 (K562-p14(ARF)) and 4 blast crisis primary CML cells (CML-BC 1-4) using vesicular stomatitis virus glycoprotein (VSV-G) pseudotyped lentiviral vector with cells transduced by empty vector as control. Fluorescence microscopy and flow cytometry were applied to measure transduction efficiency, and Western blotting assay was used to detect p14(ARF) protein of K562 cells. WST-8 method was used to determine cell growth inhibition rate of K562 cells transduced by the target gene under different concentrations of imatinib (0, 0.015, 0.062, 0.125, 0.25, 0.5, 1.0, 2.0 μmol/L). Cell apoptosis and leukemic cellular colony-forming ability were detected by Annexin V-FITC/PI dyeing using flow cytometry (FCM) and semi-solid culture method respectively.</p><p><b>RESULTS</b>Fluorescence microscopy and FCM showed that transduction efficiency (GFP positive cells) of K562-p14(ARF), K562-VSV and CML-BC1 cells were close to 100%, and CML-BC 2-4 cells were 80% to 90% on average. Results of Western blotting showed that the levels of ARF protein expression of K562 cells transduced by p14(ARF) were significantly higher than of untransduced cells; the apoptosis rate of K562-p14(ARF) was 20%; the mean apoptosis rate of 4 primary leukemic cells transduced by the p14(ARF) [(71.1±22.4)%] was significantly higher than of control group [(12.4±6.2)%] (P<0.05). Imatinib significantly inhibited the proliferation of K562-p14(ARF) cells in a dose-dependent manner. The mean leukemic cellular colony-forming unit of 4 primary leukemic cells transduced by the p14(ARF) (41.5±13.2) was significantly lower than of the control group (88.5±7.9) (P<0.05).</p><p><b>CONCLUSION</b>Increased p14(ARF) gene expression could induce apoptosis of CML cells; Moreover, it could enhance inhibitory effect on cell proliferation when combined with imatinib.</p>

Expression of p14(ARF) and E2F-1 in lung cancer in Gejiu and Xuanwei regions of Yunnan Province / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the correlations between p14(ARF) and E2F-1, and the role of their alterations in the tumorigenesis of the lung cancer in Gejiu and Xuanwei regions in Yunnan Province for providing the important experiment basis in revealing the molecular mechanism and looking for new markers for early diagnosis of lung cancer.</p><p><b>METHODS</b>The expression of p14(ARF) and E2F-1 was detected at theirs protein level by Immunohistochemistry S-P method in 30 specimens of lung cancer of Gejiu tin miners, 30 specimens of lung cancer of Xuanwei peasants and 20 specimens of normal lung tissue. E2F-1 mRNA was detected by ISH in 25 specimens of lung cancer of Gejiu tin miners, 25 specimens of lung cancer of Xuanwei peasants and 10 specimens of normal lung tissue. The positive signals were quantitatively analysed by HPIAS-100.</p><p><b>RESULTS</b>The positive unit (PU) of p14(ARF) and E2F-1 was 16.44 +/- 4.85 and 47.39 +/- 5.43 in Gejiu group, and 16.79 +/- 3.55 and 48.15 +/- 9.11 in Xuanwei group. Expression of p14(ARF) and E2F-1 protein in lung cancer of Gejiu and Xuanwei were statistically different compared with that in the normal lung (P < 0.01) respectively; The PU of E2F-1 mRNA was 48.58 +/- 7.75 in Gejiu group, and 49.41 +/- 8.53 in Xuanwei group, which was higher than that in normal tissue group. The differences were significant (P < 0.01). There was positive correlation between the expression of E2F-1 protein and E2F-1 mRNA in Gejiu group, Xuanwei group and normal group (P < 0.01, r = 0.833). The expression of p14(ARF) protein was significantly negatively correlated with the expression of E2F-1 protein (P < 0.01, r = -0.830).</p><p><b>CONCLUSION</b>There is the over-expression of E2F-1 gene and the deletion of p14(ARF) gene in the tumorigenesis of the lung cancer in Gejiu and Xuanwei regions in Yunnan Province. Over-expression of E2F-1 protein in lung cancer may be caused by enhanced transcription.</p>

Hepatitis B virus X protein inhibits hepatoma cell growth in vitro through p14(ARF)-dependent and p14(ARF)-independent pathways / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effects of hepatitis B virus X protein (HBx) on hepatoma cell growth through p14(ARF)-dependent and p14(ARF)-independent pathways.</p><p><b>METHODS</b>HBx and p14(ARF) were transfected either separately or in combination into HepG2 cells containing wt-p53 but not expressing p14(ARF). The cells were divided into 4 groups, namely pcDNA3 (control), pcDNA3HBx, pcDNA3p14(ARF), and pcDNA3HBx + pcDNA3p14(ARF) groups. Flow cytometry was used to examine the apoptosis rates and cell cycle progression of HepG2 cells in different groups. The expression of p14(ARF), MDM2, p53, and p21(WAF1) proteins were investigated by detecting the activity of p21(WAF1) promoter-luciferase and using Western blotting.</p><p><b>RESULTS</b>The apoptosis rates of HepG2 cells in pcDNA3HBx and pcDNA3p14(ARF) groups were significantly higher than that in the control group (14.11%, 13.72% vs 10.66%). Compared with the control group, pcDNA3HBx and pcDNA3p14(ARF) groups also showed significantly higher cell percentages arrested at G(0)/G(1) phase (63.62%, 61.75% vs 57.42%), luciferase activity of p21 promoter (1.25-/+0.05, 1.09-/+0.06 vs 0.77-/+0.03) and expressions of p53 and p21(WAF1). The cell apoptosis rate, percentage of cells in G(0)/G(1) phase and expression level of p14(ARF) were even higher in pcDNA3HBx+pcDNA3p14(ARF) group (18.61%, 66.74%, and 3.53-/+0.43, respectively) than in either p14(ARF) or HBx group.</p><p><b>CONCLUSION</b>HBx induces p53 expression through p14(ARF)-dependent and independent pathways to activate p21(WAF1) promoter, leading to G(0)/G(1) arrest and apoptosis of HepG2 cells.</p>

The methylation locus and frequency pattern on p16 INK4a gene promoter CpG in epidermis of patients with psoriasis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the CpG methylation locus and frequency pattern on p16 INK4a gene promoter in epidermis of p16 INK4a methylated patients with psoriasis vulgaris.</p><p><b>METHODS</b>The DNA specimens were obtained from epidermal lesion of 50 plaque psoriatic patients. Methylation specific PCR and DNA sequencing were used to detect the frequency and locus of methylation in p16 INK4a gene promoter region.</p><p><b>RESULTS</b>Approximately 50% CpG was methylated in p16 INK4a methylated patients, methylation was found in specifical locus of p16 INK4a gene promoter.</p><p><b>CONCLUSION</b>The distinct methylation pattern is showed on the p16 INK4a gene promoter region in patients with psoriasis.</p>

Methylation of E-cadherin and hMLH1 genes in Indian sporadic breast carcinomas.

Hypermethylation of promoter regions leading to inactivation of tumor suppressor genes is a common event in the progression of several tumor types. We have employed a novel restriction digestion based multiplex PCR assay to analyse the methylation status of promoter regions of tumor suppressor genes (p16, hMLH1, MGMT and E-cadherin) in sporadic breast carcinomas of Indian women. The present results indicated the absence of hypermethylation in promoter region of p16 and MGMT genes. However, 6 of the 19 (31.6%) sporadic breast carcinomas showed hypermethylation in the promoters of two of the genes analysed; three in hMLH1 and another three in E-cad. Since our earlier studies have shown lack of genetic alterations such as missense mutations and deletions in the tumor associated genes-p16, ras and p14ARF in sporadic breast tumors, the epigenetic alterations of the two genes reported in the present study could be of interest and might be among the events in the genesis/progression of sporadic breast carcinomas.

The feasibility and mechanism of recombinant adenovirus Ad - p 14 ARF in gene therapy of liver cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the feasibility and mechanism of recombinant adenovirus Ad-pl4ARF in cancer gene therapy.</p><p><b>METHODS</b>The proliferation of different liver cancer cells was assessed by morphology and trypan blue assay. Cell apoptosis was confirmed by detecting phosphatidylserine (PS) externalization with Annexin V/PI double staining. The expression of related proteins was analyzed by Western bloting. Nude mouse model bearing subcutaneous transplanted BEL7402 tumor was established to study the therapeutic ability of Ad-pl4ARF.</p><p><b>RESULTS</b>Ad-pl4ARF suppressed cell growth and proliferation, and promoted cell apoptosis of cancer cell lines with different genetic background. Ad-pl4ARF inhibited growth of liver cancer cells ( HepG2, BEL7402) in a dose-dependent manner. Ad-pl4ARF lead to overexpression of Bax and p21, the downstream regulating genes of p53. In the experimental therapy on nude mice bearing subcutaneous transplanted BEL7402 tumor, Ad-pl4ARF suppressed tumor growth significantly.</p><p><b>CONCLUSION</b>pl4ARF is a short gene and with powerful function, which are consistent with the requirements for tumor suppressor genes used in gene therapy. It may play an important role in gene therapy against malignancies in the future.</p>

Construction of recombinant adenovirus vector carrying cell cycle controlling gene-p14ARF / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The recombinant adenovirus vector carrying p14ARF gene was constructed for using in the interference therapy in signal transduction of laryngeal squamous cell carcinoma.</p><p><b>METHODS</b>The total cDNA fragment of p14ARF was cloned into the shuttle plasmid pAdTrack-CMV, with the resultant plasmid and the backbone plasmid pAdEasy-1, the homologous recombination took place in the E.Coli BJ5183 and the recombinant adenoviral plasmid was generated. The adenoviruses were packaged and amplified in the 293 cells. Then the viral titer was checked by GFP.</p><p><b>RESULTS</b>The recombinant adenovirus vector carrying p14ARF was constructed successfully. The viral titer was 2.3 x 10(9).</p><p><b>CONCLUSION</b>The recombinant adenovirus vector could introduce p14ARF gene into the laryngeal squamous cell carcinoma line or tumor tissue effectively, which would provide experimental basis for the mechanisms and further study of the interference therapy in signal transduction of laryngeal squamous cell carcinoma.</p>

Aberrant Cell Cycle Regulation in Cervical Carcinoma

Carcinoma of the uterine cervix is one of the most common malignancies among women worldwide. Human papillomaviruses (HPV) have been identified as the major etiological factor in cervical carcinogenesis. However, the time lag between HPV infection and the diagnosis of cancer indicates that multiple steps, as well as multiple factors, may be necessary for the development of cervical cancer. The development and progression of cervical carcinoma have been shown to be dependent on various genetic and epigenetic events, especially alterations in the cell cycle checkpoint machinery. In mammalian cells, control of the cell cycle is regulated by the activity of cyclin-dependent kinases (CDKs) and their essential activating coenzymes, the cyclins. Generally, CDKs, cyclins, and CDK inhibitors function within several pathways, including the p16INK4A-cyclin D1-CDK4/6-pRb-E2F, p21WAF1-p27KIP1-cyclinE-CDK2, and p14ARF-MDM2-p53 pathways. The results from several studies showed aberrant regulation of several cell cycle proteins, such as cyclin D, cyclin E, p16 INK4A, p21WAF1, and p27KIP1, as characteristic features of HPV- infected and HPV E6/E7 oncogene-expressing cervical carcinomas and their precursors. These data suggested further that interactions of viral proteins with host cellular proteins, particularly cell cycle proteins, are involved in the activation or repression of cell cycle progression in cervical carcinogenesis.

Immunohistochemical Study of p53 Mutation and p16, p14 Alterations Encoded by INK4a-ARF in Mucin-ypersecreting Bile Duct Tumor / 대한소화기학회지

BACKGROUND/AIMS: Mucin-hypersecreting bile duct tumor is rare, and has an unusual histologic characteristic of having various degrees of cellular atypia ranging from dysplasia to invasive carcinoma in the same specimen. To gain insight into the role of p16, p14 and p53 in the carcinogenic process of bile duct tumor, we analyzed the expression status of these proteins in mucin-hypersecreting bile duct tumor. METHODS: Immunohistochemical staining of p16, p14 and p53 were performed in 34 paraffin embedded tissues obtained from 22 patients of mucin-hypersecreting bile duct tumor. RESULTS: Thirty-four specimens were categorized into low-grade dysplasia (9), high-grade dysplasia (4), carcinoma in situ (CIS, 11) and invasive carcinoma (10) based on the degree of cytologic and structural atypia. p53 overexpressions were found in 6 (17.6%, 3 in CIS, 3 in invasive carcinoma) and more frequently observed in the advanced histologic stages (p<0.05). Loss of p16 staining was found only in 2 (6%) of low-grade dysplasia specimen. Loss of p14 staining was found in 21 (61.7%, 7 in low-grade dysplasia, 2 in high-grade dysplasia, 8 in CIS, and 4 in invasive carcinoma) and was frequently observed in low-grade and high-grade dysplasia compared to p53 (p<0.05). CONCLUSIONS: In mucin-hypersecreting bile duct tumor, p14 and p53 may play a role in the early and advanced stage of carcinogenesis, respectively. Further study regarding genetic and epigenetic alterations in p14 and p53 gene may be needed.

Relationship between alterations of p16INK4a and p14ARF genes of CDKN2A locus and gastric carcinogenesis / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the relationship between alterations of p16INK4a and p14ARF genes and gastric carcinogenesis.</p><p><b>METHODS</b>Tumors and gastric tissues neighboring carcinoma from 48 patients with gastric cancer were studied. Homozygous deletion, mutation, methylation of the CpG islands, mRNA expression of p16INK4a and p14ARF genes were assessed by polymerase chain reaction (PCR), PCR-single strand conformation polymorphism (SSCP), PCR based methylation assay, and reverse transcription (RT)-PCR.</p><p><b>RESULTS</b>(1) The overall homozygous deletion rate of p16INK4a and p14ARF was 35.4% (17/48), and no homozygous deletion was examined in all the gastric tissues neighboring tumor. (2) There was no point mutation of p16INK4a and p14ARF in 31 gastric cancers without homozygous deletion and in the matched gastric tissues adjacent to tumor. (3) Methylation of the CpG islands of p16INK4a and p14ARF was detected in 47.9% (23/48) of gastric cancers, while methylation was observed only in 2 of 48 gastric tissues neighboring cancers with a significant difference (P <0.01). (4) The rate of p16INK4a mRNA loss was 47.9% (23/48) in gastric cancer, and the cases of combined methylation of exons 1alpha and 2 had a higher loss rate (100%, 6/6) of p16INK4a mRNA than those of methylation form the other exons (11.8%, 2/17) (P <0.01). The loss rate of p14ARF mRNA was 45.8% (22/48) in gastric cancer, and patients with combined methylation of exons 1beta and 2 had a higher loss rate (100%, 3/3) of p14ARF mRNA than those of the methylation from the other exons (15%, 3/20) (P < 0.05). (5) The combined loss of p16INK4a and p14ARF mRNAs was examined in 1 (5.6%) of 18 cases of well and moderately-differentiated carcinomas, and 11 (36.7%) of 30 cases of poorly and not-differentiated carcinomas with significant difference (P <0.05).</p><p><b>CONCLUSION</b>p16INK4a and p14ARF genes were frequently inactivated by homozygous deletion and methylation of the 5' CpG islands in gastric cancer, which might have played an important role in the development of gastric cancer.</p>

Expression of proteins in p53 (p14ARF-mdm2-p53-p21WAF/CIP1) pathway and their significance in exocrine pancreatic carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the expression of p14(ARF), p53, mdm2 and p21(WAF/CIP1) proteins and their relationship in exocrine pancreatic carcinoma.</p><p><b>METHODS</b>Specimens of pancreatic carcinoma, adjacent non-neoplastic pancreatic tissue and pancreatic benign lesions were examined for p14(ARF), p53, mdm2 and p21(WAF/CIP1) protein expression by tissue microarray technique and immunohistochemistry.</p><p><b>RESULTS</b>The expression of p14(ARF), p53, mdm2 and p21(WAF/CIP1) proteins in pancreatic carcinoma were 35.3% (59/167), 57.5% (96/101), 64.1% (107/167) and 39.5% (66/167) respectively. The expression of p53 proteins was increased in pancreatic carcinoma (P < 0.01), while the expression of p14(ARF) and p21(WAF/CIP1) proteins was reduced (P < 0.05), as compared with that in non-neoplastic pancreatic tissue. p21(WAF/CIP1) protein expression in pancreatic carcinoma significantly correlated with the age of patients and perineural invasion (P < 0.05). p53 protein expression correlated significantly with tumor differentiation, lymph node metastasis and perineural invasion (P < 0.05). Mdm2 protein expression correlated significantly with tumor differentiation (P < 0.05), while p14(ARF) protein expression correlated significantly with the age of patients and metastasis (P < 0.05). There was also statistic correlation between the expression of these four genes (P < 0.05).</p><p><b>CONCLUSIONS</b>Overexpression of p53 and mdm2 and loss of p14(ARF) and p21(WAF/CIP1) expression may contribute to the pathogenesis of pancreatic carcinoma. These proteins play a critical role in cell cycle arrest and apoptosis after DNA damage through p14(ARF)-mdm2-p53-p21(WAF/CIP1) pathway. Detection of p53 and Mdm2 protein overexpression may be useful in evaluation of the aggressiveness of pancreatic carcinoma.</p>

Expression of p14(ARF), p16(INK4a), p53, pRb in Gastric Cancer

PURPOSE: In this study, the level of expression of p14(ARF), p16(INK4a), p53 and pRb was immunohistochemically examined according to the stage of gastric cancer, lymph node metastasis, cell differentiation and Lauren's classification. The effect on survival rate and the associations between the components were examined as well. METHODS: One hundred and fourteen patients who underwent surgery for gastric cancer were studied retrospectively using their paraffin embedded tissue and medical records. Using antibodies of p14(ARF), p16(INK4a), p53 and pRb, immunohistochemical stain was applied and their level of expression examined. RESULTS: The level of p53 expression was high when the stage of gastric cancer was more progressed, the invasiveness higher, lymph node metastasis present and cell differentiation poorer. In contrast, the level of p14ARF expression tended to be lower as the stage was more progressed, but this was not statistically significant. Expression of p16 and pRb did not show any association with stage or other pathologic findings. Expression of p53 and p14(ARF) also had a significant association with survival rate. Survival rate was lower in patients who expressed p53 than in those who did not, but it was higher in who expressed p14ARF than in those who did not. When these two were combined, patients with p14(ARF)(+)/p53(-) had the highest survival rate, whereas those with p14(ARF)(-)/p53(+)had the lowest. This demonstrated that the expressions of p14ART and p53 have value as prognostic indicators. CONCLUSION: From these results, p53 seems closely related to stage and other pathologic findings. Furthermore, p14(ARF) and p53 showed a statistically significant relationship with survival rate, making them valuable as prognostic indicators after surgery. In combination, it would be possible to predict a more accurate prognosis.

Analysis of Epigenetic Marker of Bladder Cancer / 대한비뇨기과학회지

PURPOSE: Promoter methylation provides an alternative pathway for the loss of tumor suppressor gene functions. This epigenetic change is a new marker for human cancers. We herein investigated the aberrant methylation profile of bladder cancer to identify the epigenetic markers that are useful for the diagnosis of bladder cancer. MATERIALS AND METHODS: Gene promoter methylation was analyzed in 50 bladder transitional cell cancer (TCC) tissues and 30 nonmalignant bladder mucosal tissues including 21 tissue samples with normal histology and 9 tissue samples with inflammation. The methylation status of 13 tumor suppressor genes was analyzed by methylation specific polymerase chain reaction and bisulfite genomic sequencing. The methylation frequency and methylation index were comparatively analyzed in each group of tissues. RESULTS: Bladder TCC showed a high frequency of promoter hypermethylation for RASSF1A(62.0%), RARbeta2(54.0%), E-cadherin(48.0%), p16INK4A(46.0%), p14ARF(34.0%) and H-cadherin(32.0%), whereas, methylation was less common for MGMT(18.0%), DAPK(14.0%) and p15INK4B(10.0%), and methylation was rare for GSTP1(4.0%), FHIT(2.0%), APC(2.0%) and MLH1(2.0%). Benign bladder mucosa rarely showed aberrant methylation except for E-cadherin (10.0%) and RARbeta2(10.0%). The methylation index of bladder TCC(0.25) was significantly higher than that of the benign bladder mucosal tissues(0.03, p<0.01). Remarkably, all of the bladder cancer tissues showed aberrant methylation of at least one of 6 genes including RASSF1A, RARbeta2, p16INK4A, p14ARF, E-cadherin and H-cadherin, whereas only 5 of 30 (16.7%) benign bladder mucosa tissues showed the same findings. CONCLUSIONS: Aberrant promoter methylation of tumor suppressor genes may be a critical step in the development of bladder TCC. Aberrant promoter methylations of RASSF1A, RARbeta2, p16INK4A, p14ARF, E-cadherin and H-cadherin may be promising epigenetic markers for the diagnosis and follow up of bladder cancer.

Significance of the Methylation of Cyclin-Dependent Kinase Inhibitor 2A gene in the Prognosis of Osteosarcoma / 대한정형외과학회잡지

PURPOSE: The methylation status of the CpG promoter regions of the p16INK4A and p14ARF genes, mutations of 4 exons of the CDKN2A gene, and the expression of the corresponding proteins were examined. Prognostic implications were assessed in osteosarcoma. MATERIALS AND METHODS: Methylation-specific PCR, sequence analysis, and immunohistochemical staining were performed upon 32 frozen osteosarcoma tissues. RESULTS: Methylation of p16INK4A was found in 16%, and methylation of p14ARF in 47%. Metastasis and poor survival was statistically related to the methylation of p14ARF. The methylation of p14ARF correlated with the repression of the corresponding protein, and repression of p14ARF with the repression of p21 and of wild type of p53. No sequence alterations were found in the four exons of the CDKN2A gene. Methylation of p14 showed highest hazard ratio by multivariate survival analysis. CONCLUSION: Our data suggest that methylation of the CDKN2A gene seems to be the main mechanism of protein repression. For p14ARF, the methylation of its promoter region was related to the repression of p21 and wild type p53, distant metastasis and a poor prognosis. Further study regarding cell cycle regulatory factors should shed light on oncogenesis and the possibility of a new treatment strategy for osteosarcoma.

Relationship between alterations of p16(INK4a) and p14(ARF) genes of CDKN2A locus and gastric carcinogenesis / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the relationship between alterations of p16(INK4a) and p14(ARF) genes and gastric carcinogenesis.</p><p><b>METHODS</b>The tumors and neighboring gastric tissues from 48 patients with gastric cancer were studied. The homozygous deletion, mutation, methylation of the CpG islands, and mRNA expression of p16(INK4a) and p14(ARF) genes were assessed by PCR, PCR-SSCP, PCR based methylation assay, and RT-PCR.</p><p><b>RESULTS</b>(1) The homozygous deletion rate of p16(INK4a) and p14(ARF) was 35.4% (17/48), and no homozygous deletion was examined in any gastric tissue neighboring the tumor. (2) There was no point mutation of p16(INK4a) and p14(ARF) in 31 gastric cancers without homozygous deletion or in the matched gastric tissues adjacent to the tumor. (3) Methylation of the CpG islands of p16(INK4a) and p14(ARF) was detected in 47.9% (23/48) of gastric cancers, while methylation was observed only in 2 of 48 gastric tissues neighboring the cancer with a significant difference (P < 0.01). (4) The loss rate of p16(INK4a) mRNA was 47.9% (23/48) in gastric cancer, and the patients of the combined methylation of exons 1alpha and 2 had a higher loss rate (100%, 6/6) of p16(INK4a) mRNA than those of the methylation of the other exons (11.8%, 2/17, P < 0.01); the loss rate of p14(ARF) mRNA was 45.8% (22/48) in gastric cancer, and patients with the combined methylation of exons 1beta and 2 had a higher loss rate (100%, 3/3) of p14(ARF) mRNA than those of the methylation of the other exons (15%, 3/20, P < 0.05). (5) The combined loss of p16(INK4a) and p14(ARF) mRNAs was examined in 1 (5.6%) of 18 patients of well and moderately-differentiated carcinomas, and 11 (36.7%) of 30 patients of poorly and not-differentiated carcinomas with a significant difference (P < 0.05).</p><p><b>CONCLUSION</b>p16(INK4a) and p14(ARF) genes are frequently inactivated by homozygous deletion and methylation of the 5'CpG islands in gastric cancer, which may play an important role in the carcinogenesis of gastric cancer.</p>

p14ARF upregulation of p53 and enhanced effects of 5-fluorouracil in pancreatic cancer / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the synergistic antitumor effects of combined use of p14ARF gene and 5-fluorouracil (5-Fu) in pancreatic cancer.</p><p><b>METHODS</b>A human pancreatic cancer cell line PC-3 was transfected with lipofectin-mediated recombinant p14ARF gene, and was then administered with 5-Fu. Cell growth, morphological changes, cell cycle, apoptosis, and molecular changes were measured using the MTT assay, flow cytometry, RT-PCR, Western blotting, and immunocytochemical assays.</p><p><b>RESULTS</b>After transfection of p14ARF, cell growth was obviously inhibited, resulting in an accumulation of cells in the G(1) phase. The proportion of cells in the G(1) phase was significantly increased from 58.51% to 75.92%, and in the S and G(2)/M phases decreased significantly from 20.05% to 12.60%, and from 21.44% to 11.48%, respectively, as compared with those of the control groups. PC-3/p14ARF cells that underwent 5-Fu treatment had significantly greater G(2)/M phase accumulation, from 11.48% to 53.47%. The apoptopic index was increased in PC-3/p14ARF cells from 3.64% to 19.62%. The MTT assay showed p14ARF-expressing cells were significantly more sensitive to 5-Fu (0.01 - 10 mg/L) than those devoid of p14ARF expression (P < 0.01). Western blotting showed p14ARF upregulates p53 expression.</p><p><b>CONCLUSION</b>Combined use of p14ARF gene and 5-Fu acts synergistically to inhibit pancreatic cancer cell proliferation, suggesting a new anticancer strategy.</p>

Alterations of 9p21-22 Region Encoding Genes in Primary Glioblastomas

BACKGROUND: Glioblastomas are one of the most common and aggressive malignant glial tumors occuring in the central nervous system. This study analyzed the status of p15INK4b, p14ARF, p16INK4a, MTAP, IFNA, and IFNB genes in 36 primary glioblastomas to investigate whether the inactivation of these genes participate in primary glioblastoma tumorigenesis. METHODS: We used polymerase chain reaction, polymerase chain reaction/single strand conformational polymorphism (PCR/SSCP) analysis, and methylation-specific PCR. RESULTS: Homozygous deletions at the p16INK4a gene were detected in 11 cases (30.5%) of 36 primary glioblastomas, and the promoter hypermethylation was found in 3 cases (8.3%) of 36 primary glioblastomas. In mutational analysis for the p16INK4a gene by PCR/SSCP, there was no abnormal mobility-shifted band in 36 cases of primary glioblastomas. The overall frequency of p16INK4a alterations including homozygous deletion and promoter hypermethylation in 36 primary glioblastomas was 38.8% (14 of 36). Deletions of p15INK4b were noted in 4 cases (11.1%), whereas deletions of the p14ARF and MTAP genes were detected in 1 case of 36 cases of primary glioblastomas. But deletions of the INFA and B genes were not found. CONCLUSIONS: These results suggest that alterations of the p16INK4a gene can be important mechanisms of the tumorigenesis of primary glioblastomas, and the p16INK4a gene is inactivated by mechanisms including homozygous deletion and promoter hypermethylation.