OBJECTIVETo investigate the synergistic antitumor effects of combined use of p14ARF gene and 5-fluorouracil (5-Fu) in pancreatic cancer.

METHODSA 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.

RESULTSAfter 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.

CONCLUSIONCombined use of p14ARF gene and 5-Fu acts synergistically to inhibit pancreatic cancer cell proliferation, suggesting a new anticancer strategy.

Fluorouracil ; pharmacology ; Humans ; Pancreatic Neoplasms ; genetics ; therapy ; Transfection ; Tumor Cells, Cultured ; Tumor Suppressor Protein p14ARF ; genetics ; Tumor Suppressor Protein p53 ; genetics ; Up-Regulation ; physiology

OBJECTIVETo 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.

METHODSThe 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.

RESULTSThe 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).

CONCLUSIONThere 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.

China ; E2F1 Transcription Factor ; genetics ; metabolism ; Female ; Humans ; Lung Neoplasms ; metabolism ; Male ; RNA, Messenger ; genetics ; Tumor Suppressor Protein p14ARF ; metabolism

OBJECTIVETo explore the effects of hepatitis B virus X protein (HBx) on hepatoma cell growth through p14(ARF)-dependent and p14(ARF)-independent pathways.

METHODSHBx 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.

RESULTSThe 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.

CONCLUSIONHBx 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.

Carcinoma, Hepatocellular ; genetics ; pathology ; virology ; Cell Line, Tumor ; Cell Proliferation ; Cyclin-Dependent Kinase Inhibitor p21 ; genetics ; Humans ; Liver Neoplasms ; genetics ; pathology ; virology ; Promoter Regions, Genetic ; Trans-Activators ; genetics ; Transfection ; Tumor Suppressor Protein p14ARF ; genetics ; Tumor Suppressor Protein p53 ; genetics

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.
Adult ; Aged ; Bile Duct Neoplasms/*genetics/secretion ; Carcinoma/*genetics ; Cyclin-Dependent Kinase Inhibitor p16/*genetics/secretion ; English Abstract ; Female ; *Genes, p16 ; *Genes, p53 ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Mucins/*secretion ; *Mutation ; Tumor Suppressor Protein p14ARF/*genetics

OBJECTIVETo investigate the relationship between alterations of p16INK4a and p14ARF genes and gastric carcinogenesis.

METHODSTumors 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.

RESULTS(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).

CONCLUSIONp16INK4a 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.

Adenocarcinoma ; genetics ; Adolescent ; Adult ; Aged ; Cyclin-Dependent Kinase Inhibitor p16 ; genetics ; DNA Methylation ; Female ; Gene Deletion ; Genes, p16 ; Humans ; Male ; Middle Aged ; RNA, Messenger ; analysis ; Stomach Neoplasms ; genetics ; Tumor Suppressor Protein p14ARF ; genetics

OBJECTIVETo investigate the relationship between alterations of p16(INK4a) and p14(ARF) genes and gastric carcinogenesis.

METHODSThe 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.

RESULTS(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).

CONCLUSIONp16(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.

Adolescent ; Adult ; Aged ; Cyclin-Dependent Kinase Inhibitor p16 ; genetics ; DNA Methylation ; Gene Deletion ; Genes, p16 ; Humans ; Middle Aged ; RNA, Messenger ; analysis ; Stomach Neoplasms ; genetics ; Tumor Suppressor Protein p14ARF ; genetics

OBJECTIVETo explore the feasibility and mechanism of recombinant adenovirus Ad-pl4ARF in cancer gene therapy.

METHODSThe 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.

RESULTSAd-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.

CONCLUSIONpl4ARF 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.

Adenoviridae ; genetics ; Animals ; Apoptosis ; Blotting, Western ; Carcinoma, Hepatocellular ; metabolism ; pathology ; therapy ; Cell Line, Tumor ; Cell Proliferation ; Genetic Therapy ; methods ; Humans ; Liver Neoplasms, Experimental ; metabolism ; pathology ; therapy ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Proto-Oncogene Proteins p21(ras) ; metabolism ; Recombinant Fusion Proteins ; genetics ; Transfection ; Tumor Suppressor Protein p14ARF ; genetics ; Tumor Suppressor Protein p53 ; metabolism ; Xenograft Model Antitumor Assays ; bcl-2-Associated X Protein ; metabolism

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.
Carcinoma ; Cell Cycle ; Cell Division ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p16 ; metabolism ; Gene Silencing ; Humans ; Hyaluronan Receptors ; metabolism ; Lentivirus ; Nasopharyngeal Carcinoma ; Nasopharyngeal Neoplasms ; genetics ; pathology ; Neoplastic Stem Cells ; cytology ; Polycomb Repressive Complex 1 ; genetics ; RNA, Messenger ; RNA, Small Interfering ; Tumor Suppressor Protein p14ARF ; metabolism ; Tumor Suppressor Protein p53 ; metabolism

OBJECTIVETo investigate the CpG methylation locus and frequency pattern on p16 INK4a gene promoter in epidermis of p16 INK4a methylated patients with psoriasis vulgaris.

METHODSThe 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.

RESULTSApproximately 50% CpG was methylated in p16 INK4a methylated patients, methylation was found in specifical locus of p16 INK4a gene promoter.

CONCLUSIONThe distinct methylation pattern is showed on the p16 INK4a gene promoter region in patients with psoriasis.

Adolescent ; Adult ; Aged ; Base Sequence ; CpG Islands ; genetics ; Cyclin-Dependent Kinase Inhibitor p16 ; genetics ; metabolism ; DNA Methylation ; genetics ; Epidermis ; metabolism ; Female ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Polymerase Chain Reaction ; Promoter Regions, Genetic ; genetics ; Psoriasis ; genetics ; Sequence Alignment ; Tumor Suppressor Protein p14ARF ; genetics ; Young Adult