Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

p53 protein accumulation, thought to be caused by p53 gene mutation, is closely related to poor prognosis of patients with certain types of carcinomas. The progression of esophageal squamous cell carcinoma (SCC) is also strongly suspected to depend on the p53 tumor suppressor gene. Formalin-fixed, paraffin-embedded sections were taken from 25 patients who underwent esophagectomy for SCC. Fourteen patients had no preoperative therapy (control group), while the other 11 patients received preoperative radiotherapy (radiation group). There was no difference in pathological TNM classification between the two groups. These sections were examined by immunostaining with monoclonal antibody PAb 1801 to determine the accumulation of p53 protein, and apoptotic frequency was determined by TdT mediated dUTP-biotin nick end-labeling (TUNEL). In the control group, well to moderately differentiated cases showed a significantly higher AI (apoptotic index which is the number of apoptotic cells among 1000 cancer cells. %0) (51.7+/-83.4) than poorly differentiated cases (AI=1.3+/-1.0) (P<0.05). Similar results were obtained in the radiation group. The former group included 4 cases of p53 grade 4 (p53 protein detected in over 70% of the tumor cells), and the latter included 2. Few apoptotic cells were observed in any of 6 tumor tissues. In each patient, tumor cells with accumulated p53 protein were very rare to be apoptotic. On the other hand, apoptosis was observed in tumor cells without p53 protein accumulation. Spontaneous apoptosis in esophageal SCC can be induced more easily in differentiated than in poorly differentiated cases. This tendency may be enhanced by preoperative radiotherapy. Extensive p53 protein may suppress apoptotic induction in esophageal squamous cell carcinomas.
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PMID:Suppressed apoptotic induction in esophageal squamous cell carcinomas expressing extensive p53 protein. 900 43

The tumor suppresser p53 is a cell cycle checkpoint protein that contributes to the preservation of genetic stability by mediating either a G1 arrest or apoptosis in response to DNA damage. p53 causes growth arrest through transcriptional activation of the cyclin-dependent kinase inhibitor p21. During p53-mediated suppression of cell proliferation, p21 is important for coordinating cell cycle progression, DNA replication, and repair of damaged DNA. The purpose of this study is to investigate the expression of p53 and p21 mRNA in association with DNA damage and normal repair in acute immune complex alveolitis in mice. Male ICR mice were injected intravenously with IgG antibodies against oval albumin, aerosolized with oval albumin solution, and killed at 4, 6, 12, 24, and 48 hours and 1 week after aerosolization. We assessed the expression of p53 and p21 mRNA by reverse transcriptase (RT)-PCR and by RT in situ PCR. We also assessed DNA damage by terminal deoxynucleotidyl transferase mediated biotin-dUTP nick-end-labeling (TUNEL) and by gel electrophoresis of DNA extracted from lung tissues. The results of RT-PCR and RT in situ PCR showed that p53 and p21 mRNA were concurrently up-regulated at 4 to 48 hours after aerosolization in alveolar epithelial cells. Bronchial and alveolar epithelial cells were positively stained by TUNEL in this period but not at 1 week after aerosolization or in control mice. The result of electrophoretic analysis of DNA was compatible with that of TUNEL. These studies suggest that the responses of p53 and p21 mRNA are associated with physiologic processes of DNA damage and repair in acute immune complex alveolitis in mice.
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PMID:P53 and p21 (Waf1/Cip1) mRNA expression associated with DNA damage and repair in acute immune complex alveolitis in mice. 904 52

Technical limitations are associated with conducting successful in situ hybridization. In this study, three cell types including a tumor neuroblastoma cell line (Neuro-2a), an oligodendrocyte primary culture, and a nonneuronal acute lymphoblastic leukemia cell line (Reh) were used to conduct successful nonradioactive in situ hybridization. Two cDNA probes were used. A 1 kb probe was used to identify the expression of proteolipid protein (PLP) mRNA in a primary culture of oligodendrocytes. A 760 bp cDNA was used to identify the expression of ubiquitin C-terminal hydrolase (UCH-L1) mRNA in Neuro-2a and Reh cells. The probes were labeled with digoxigenin-11-dUTP, denatured, and hybridized with cells fixed on coverslips. The efficiency of the labeling was tested using dot blot analysis by comparing the intensity of our labeled probes with known concentration of the probe labeled by the provider. The nonspecific signals were washed off, followed by detection of a signal specific to the gene. The specificity of the probes was determined by treating the cells with RNase A, hybridizing with bacterial Dig-labeled cDNA (pBR322) and hybridizing the tissues in the absence of labeled probe. During the labeling step, we found that addition of co-precipitants, such as tRNA or glycogen, during precipitation of the labeled probe followed by overnight incubation at -20 C is essential for good recovery of labeled cDNA. Dissolving the labeled probe in a buffer solution containing sodium dodecyl sulfate improves the quantity of the labeling. At the cellular level, prehybridization treatments optimize the permeability of the cell and allow efficient penetration of the labeled probe. Fixing with paraformaldehyde or an ethanol-acetic acid mixture can preserve the structure of cultured cells. To increase the signal to noise ratio, cells were treated with 0.2 N HCl followed by extensive washes using a solution with a high salt concentration and containing dextran sulfate. This treatment significantly improves the signal and reduces the background in cell cultures, but not in tissue sections. The ability to reuse the labeled probe-hybridization mixture is another advantage for using nonradioactive in situ hybridization.
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PMID:Nonradioactive in situ hybridization histochemistry in leukemic and nonleukemic culture. 906 9

We demonstrated previously the antitumoral and antiproliferative effects of sodium phenylacetate (NaPA) on malignant breast epithelial MCF-7ras cells and its lack of toxicity. The present in vivo protocols were as follows: (1) a control group; (2) a NaPA-receiving group (450 mg/kg) through s.c. osmotic pumps (ALZA Corp.) for 2 weeks, followed by 2 weeks with no treatment; and (3) a tamoxifen (TAM)-receiving group (20 mg/kg two times per week). The second group was further divided as follows: (a) a group receiving same doses of NaPA; (b) a TAM-receiving group; and (c) a group receiving both NaPA and TAM. Although tumors treated by TAM alone (group 3) showed progressive regrowth after 6 weeks, indicating an escape from antiestrogen inhibition, the TAM-administered group, following 2 weeks of NaPA pretreatment (group 2b), showed significant tumor regression of about 40% after 8 weeks. This effect was amplified to over 60% (P < 0.001) by simultaneous administration of the two drugs (group 2c). The last group displayed about 30% apoptotic-like nuclei, together with lower proliferation index, and less tumor vascularization, as compared to less than 5% terminal deoxytransferase-mediated dUTP-X nick end labeling-positive nuclei, highly vascularized tumors, in the TAM-treated group. Furthermore, in vitro administration of 4-OH-tamoxifen induced a Bcl-2 up-regulation in MCF-7ras cells, which was completely abolished by NaPA pretreatment. The combination of NaPA and OHT induced significant cell differentiation with cell cycle accumulation in the G0-G1 phase.
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PMID:Tumor growth inhibition, apoptosis, and Bcl-2 down-regulation of MCF-7ras tumors by sodium phenylacetate and tamoxifen combination. 906 63

To analyse growth characteristics of human renal cell tumors, 66 renal cell carcinomas and one oncocytoma were investigated concerning the proliferative activity by immunohistochemical demonstration of the Ki-67 antigen (clone MIB1) and the apoptotic rate using the terminal deoxynucleotidyl-transferase mediated dUTP-fluorescin nick end labelling (TUNEL) method. The TUNEL method indicates DNA double strand breaks considered as a hallmark of programmed cell death (apoptosis). Apoptotic cells were observed in 57 of 67 cases. The apoptotic rate (percentage of stained tumor cells) varied from 0% to 54.1%. GI carcinomas possessed a statistically significant higher apoptotic rate than GII/GIII carcinomas. The proliferation index (percentage of Ki-67 labelled cells) ranged from 0.09% to 22.3%. The well differentiated carcinomas (GI) showed statistically lower proliferative activity than moderate and poorly differentiated carcinomas (GII/GII). The clear cell variant of renal cell carcinoma expressed a higher apoptotic rate than the chromophilic variant. A statistical correlation between apoptosis/proliferation and occurrence of metastasis could not be established. In progression from well to less differentiated renal cell carcinoma the decrease of apoptotic rate, as well as the increase of the proliferative activity, contributes to a rapid tumor growth.
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PMID:Quantitative evaluation of apoptosis and proliferation in renal cell carcinoma. Correlation to tumor subtype, cytological grade according to thoenes-classification and the occurrence of metastasis. 911 68

Rats transplanted with the androgen-sensitive, syngeneic Dunning R3327 PAP prostatic tumor were castrated and treated with estrogen or vehicle for 4, 12 and 24 hr and for 6 weeks. Tumor growth was retarded by castration and further inhibited by estrogen. Immediately after castration, an increased number of activated macrophages and T-cells were found in parallel with increasing apoptotic tumor cells. Administration of an immunosuppressive drug, FK 506, abolished the growth-inhibitory effects of castration and estrogen. The tumor growth rate correlated negatively with the number of R73- and OX8-positive T-cells and NK cells and with the percentage of ED3-positive macrophages. There was a positive correlation between the percentage of TdT-mediated-dUTP nick end labeling (TUNEL)-positive apoptotic cells and that of ED3-positive cells. Our results suggest that apoptosis of prostatic carcinoma cells induced by endocrine treatment in vivo is partly due to a rapid infiltration by immunocompetent cells.
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PMID:Apoptosis in rat prostatic adenocarcinoma is associated with rapid infiltration of cytotoxic T-cells and activated macrophages. 913 83

bcl-2 protein and Ki-67 (MIB-1) were studied in 32 acinic cell carcinomas (ACCs), all with a minimum of 5 years' clinical follow-up. Tumour apoptosis was evaluated by TdT dUTP nick end labelling (TUNEL) and by morphological criteria. Five patients died of their disease. Patients with stage I tumours had significantly better survival compared with other stages (P < 0.05). Patients with MIB-1-negative tumours had significantly better survival than patients with MIB-1-positive tumours (P = 0.05). This study confirms a previous report that MIB-1 is an independent prognostic factor for survival in patients with ACC. Stage I tumours had high expression of bcl-2 protein, but there was no difference when compared with other stages. TUNEL positivity was most prevalent in stage I tumours, compared with stages II, III, and IV (P < 0.05), probably indicating more apoptosis. This could imply a capacity of stage I tumours ('early tumours') for early selection of tumour cells for elimination by apoptosis. There was no significant difference between expression of bcl-2 and TUNEL, between these parameters and clinical outcome, or between any parameter and morphological subclassification. We conclude that MIB-1 has prognostic value in ACC. Clinical staging, bcl-2, and TUNEL are also potentially useful as prognostic markers.
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PMID:Tumour growth fraction and apoptosis in salivary gland acinic cell carcinomas. Prognostic implications of Ki-67 and bcl-2 expression and of in situ end labelling (TUNEL). 915 20

Preoperative embolization of meningiomas is performed to decrease blood loss at surgery. While it is also expected to reduce tumor recurrence by producing necrosis at the site of dural attachment, very little has been described about what happens to the non-necrotic tumor cells. We investigated how the proliferative activities of meningiomas were modified after embolization. In nine meningiomas which were embolized preoperatively, proliferative potentials and expression of cell cycle inhibitors were assessed immunohistochemically using MIB-1, anti-53 (DO-1 and DO-7), and anti-p21 (WAF1/CIP1) monoclonal antibodies. To determine whether a cell underwent apoptotic death besides necrosis, we applied the terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling method. Results were compared with control meningiomas without embolization. MIB-1 positive cells often gathered in perinecrotic areas, although the mean MIB-1 staining index of the embolized meningiomas was not significantly different from the control. p53 and its downstream effector p21 accumulated mainly in the perinecrotic areas in eight of the nine embolized meningiomas. Apoptosis was also observed in the concomitant areas. Double staining for both MIB-1 and p21 frequently showed positive cells for both antibodies. The accumulation of MIB-1 positive cells in the embolized meningiomas may not be a sign of fast growth or malignancy, but it may implicate arrest of cell cycle by the p21. This study indicates that embolized meningiomas exhibit not only necrosis but also apoptosis and cell cycle arrest. The latter effects appear to be at least partly p53 dependent.
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PMID:p53 accumulation and apoptosis in embolized meningiomas. 919 99

Spontaneous regression of chiasmal gliomas without associated neurofibromatosis has been occasionally described. In this paper we present two patients with chiasmal glioma whose tumors decreased in size during the postoperative course. Neither patient received radiotherapy or chemotherapy. We examined the proliferative activity of the excised tumors by determining the Ki-67 labeling index and searched for apoptotic cells using the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method. The Ki-67 labeling index of the tumor of case 1 was 0.63%, and apoptotic cells were detected in some areas. In case 2, the Ki-67 labeling index was 19.5% and a large number of apoptotic cells were evident. As estimated from the respective apoptosis data, our results would indicate that tumor regression may occur when the rate of cell loss is greater than that of tumor growth.
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PMID:Chiasmal gliomas with spontaneous regression: proliferation and apoptosis. 920 60

To examine in vivo the validity of the results of experiments in vitro, we analyzed the relationship between p53 gene status and apoptotic cell death of human gastric intestinal-type adenocarcinomas. Surgical specimens were classified into two categories: 18 gastric cancers with nuclear p53 protein (A), and 17 gastric cancers without nuclear p53 protein (B). Polymerase chain reaction-single strand conformation polymorphism disclosed a shifted band that corresponded to a mutation in the p53 gene in 13 cases (72%) in category A and 3 cases (18%) in category B, the frequency being significantly higher in the former (P < 0.05). Apoptotic cells were identified from routinely stained sections and by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL). The TUNEL index [TI; (the number of TUNEL-positive apoptotic cells/the total number of tumor cells) x 100] was 3.8 +/- 1.4% in category A and 4.9 +/- 1.2% in category B, the value being significantly lower in the former (P < 0.05). The proliferating cell nuclear antigen index, defined similarly to the TI, was 56.4 +/- 16.3% in category A, and it was significantly higher than that in category B (P < 0.05). The immunohistochemically detected expression of p21CIP1/WAP1 did not differ between the two categories, while Bax-positive tumor cells were more frequently detected in category A. These results indicate that (1) expression of a mutated p53 gene attenuates apoptotic cell death of gastric cancer, in accordance with the previous in vitro finding that p53 gene mutation provides a possible selective advantage for tumor cell proliferation, and (2) apoptosis is related not only to expression of p53 and the stage of the cell cycle, but also to p53-independent and cell cycle-independent events.
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PMID:Evidence that expression of a mutated p53 gene attenuates apoptotic cell death in human gastric intestinal-type carcinomas in vivo. 924 3


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