Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There are many reports of cell lines being established from human oral squamous-cell carcinomas but apparently none of cell lines from dysplastic or "pre-malignant" oral mucosa. We describe here the isolation and characterization of a cell line, DOK (dysplastic oral keratinocyte), from a piece of dorsal tongue showing epithelial dysplasia. The tissue was obtained from a 57-year-old man who was a heavy smoker prior to the appearance of a white patch on his tongue. Eleven years later a squamous-cell carcinoma developed at the site and was excised. Subsequently the remaining dysplasia was removed, and it was from a piece of this that the primary cell cultures which eventually gave rise to DOK were initiated. The DOK line has been single-cell cloned and is apparently immortal. It grows in the absence of 3T3 feeder cells, is anchorage-dependent for growth and is non-tumorigenic in nude mice. The keratin profile of the cells shows a striking similarity to that of the original tongue dysplasia. The karyotype of DOK is aneuploid and complex. By PCR and oligonucleotide hybridization on dot blots, codons 12, 13 and 61 of Ha-ras, Ki-ras and N-ras in DNA extracted from DOK cells were shown to be normal. Immunohistochemistry showed no abnormal, i.e., elevated expression of the onco-suppressor protein p53. Because of its origin and partially transformed phenotype, DOK presents an opportunity to study whether specific carcinogens associated with tobacco and areca nut can cause malignant transformation of oral keratinocytes in vitro.
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PMID:DOK, a cell line established from human dysplastic oral mucosa, shows a partially transformed non-malignant phenotype. 145 32

Adamantinoma of long bones is a rare malignant tumor composed of cells with epithelial characteristics in various differentiation patterns surrounded by fibrous cells. Evidence as to whether this neoplasm should be designated as an epithelial bone tumor or a biphasic sarcoma with both epithelial and mesenchymal features is lacking. In this study the nature of the mesenchymal and epithelial components of adamantinoma was investigated by DNA flow cytometry, DNA image cytometry, p53 immunohistochemistry, and polymerase chain reaction-based loss of heterozygosity detection at the p53 locus. Specimens from 6 of 15 patients (40%) analyzed by flow cytometry had an aneuploid DNA index. Image cytometry analysis of Feulgen-stained paraffin sections of 6 aneuploid and 2 diploid tumors revealed that aneuploid nuclei were detected in cells with an epithelial phenotype only, whereas all fibrous cells were diploid. Immunohistochemistry for p53 on specimens from 25 patients revealed moderate or strong immunoreactivity in 12 tumors (48%) restricted to the epithelial cells. Loss of heterozygosity at the p53 locus could be confirmed in the epithelial component of an immunohistochemically p53-positive tumor. Additionally, sections of 7 lung metastases were studied histologically. Only keratin-positive epithelial cells, predominantly in the spindle cell pattern, were present in these metastases, whereas the osteofibrous tissue present in the primary tumors was not detected. These results suggest that either adamantinoma consists of a malignant epithelial part with a reactive osteofibrous stroma or that the malignant epithelial cells develop next to a proliferating benign fibrous component. Additional analysis of common genetic abnormalities in the fibrous and epithelial cells of adamantinoma is therefore indicated.
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PMID:DNA aberrations in the epithelial cell component of adamantinoma of long bones. 749 1

Transgenic mice that expressed v-fos exclusively in the epidermis by means of a human keratin K1-based targeting vector (HK1.fos) developed preneoplastic epidermal hyperplasia and hyperkeratosis after long latency and an associated wound promotion stimulus. To assess the requirements for papilloma formation and malignant conversion and determine the sensitivity to a chemical promotion stimulus, HK1.fos mice were promoted with 12-O-tetradecanoylphorbol-13-acetate (TPA). HK1.fos mice were sensitive to TPA promotion but developed papillomas only after long latency (20-30 weeks of promotion) and in relatively few numbers per animal, suggesting the necessity of an additional genetic event prior to overt lesion formation. Consistent with this idea, at 60 weeks, on cessation of TPA promotion, these HK1.fos TPA-papillomas were found to be autonomous, TPA-independent tumors which persisted, grew larger, and converted to malignancy. Analysis of HK1.fos tumor RNA and DNA identified endogenous c-rasHa mutations at codons 12 and 61 in papillomas and carcinomas; however, no p53 tumor suppressor gene mutations were detected. These data indicate that epidermal expression of v-fos induces sensitivity to TPA promotion, but since additional genetic events, such as endogenous c-rasHa activation, appear to be required in tumorigenesis, v-fos may predominantly play a role in the mechanism of promotion to achieve papilloma autonomy and TPA independence. Furthermore, spontaneous malignant conversion in this model does not appear to involve mutations in the p53 tumor suppressor gene.
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PMID:12-O-tetradecanoylphorbol-13-acetate promotion of transgenic mice expressing epidermal-targeted v-fos induces rasHA-activated papillomas and carcinomas without p53 mutation: association of v-fos expression with promotion and tumor autonomy. 754 54

The present study compared two microwave based antigen-retrieval solutions in their ability to unmask antigenic determinants in formalin-fixed and paraffin-embedded tissues for Immunostaining. In this regard, two widely used antigen-retrieval solutions, namely 0.05 M glycine-HCl buffer, pH 3.6, containing 0.01% (w/v) (EDTA) and 0.1 M sodium citrate buffer, pH 6.0, were evaluated for (1) their effectiveness in unmasking a wide range of antigenic determinants (2) their ability to yield reproducible results (3) the lack of deleterious effects in any antibody antigen systems of interest. Both of these antigen-retrieval solutions resulted in greatly improved immunostaining following microwave-heating of dewaxed tissue sections for 2 x 5 min. Glycine-HCl buffer solution resulted in stronger immunostaining with antibodies to nuclear antigens [androgen receptor (AR), estrogen receptor (ER), progesterone receptor (PR), p53, proliferating cell nuclear antigen (PCNA), Ki-67 and MIB-1], cytoplasmic antigens (actin and factor-VIII) and cell-surface antigens [Cu-18, epithelial membrane antigen (EMA) and MT-1 (CD43)], whereas sodium citrate buffer yielded superior immunostaining with antibodies to vimentin, and some cell-surface antigens [common leukocyte antigen (CLA) (CD45) and UCHL-1 (CD45RO)]. The effect of unmasking the epitopes recognized by antibody to PCNA was equally effective with either of the antigen-retrieval solutions. Antibodies to pan-keratin, prostatic acid phosphatase (PAP), B lymphocyte antigen (BLA.36, CD20CY) and L26 (CD20) exhibited no enhancement in the intensity of staining with either of the antigen-retrieval solutions.
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PMID:Comparison of two microwave based antigen-retrieval solutions in unmasking epitopes in formalin-fixed tissue for immunostaining. 754 61

Serum-free cultures of normal human buccal epithelial cells were transfected with a plasmid containing the SV40 T-antigen (SV40T) gene. Two major lines developed that showed extended lifespans (between 30 and 40 weeks) as compared with the controls (approximately 6 weeks). Continued growth through one or two crises generated several sublines. They expressed the epithelial marker keratin and also exhibited nuclear expression of SV40T. The lines showed abnormal karyotypes with both numerical and structural aberrations and variably responded to agents that normally inhibit growth and/or induce terminal differentiation, i.e. transforming growth factor-beta 1 and fetal bovine serum. One of the lines, termed SVpgC2a, developed into an apparently immortal line, since it had undergone more than 700 population doublings from over 2 years in culture. Further characterization of this line demonstrated its clonal origin, with integration of two copies of SV40T at the same site and the presence of both normal retinoblastoma and wild-type p53 proteins. This line showed high resistance to growth inhibition by transforming growth factor-beta 1 and serum similar to that shown by buccal carcinoma cell line SqCC/Y1. Neither SVpgC2a nor its parental lines were tumorigenic when injected into athymic nude mice, whereas the SqCC/Y1 cells induced tumors. The various lines with extended but finite lifespans, complemented by one immortalized line, which retained non-malignant properties upon extended culture, provide a battery of model systems that will be useful for studying mechanisms of human oral carcinogenesis.
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PMID:Characterization of human buccal epithelial cells transfected with the simian virus 40 T-antigen gene. 758 60

Squamous carcinoma of the vulva (SCV) is an uncommon neoplasm of uncertain etiology. There is evidence that there are two subgroups of SCV, one associated with human papilloma virus (HPV) and a second HPV-negative group. The UCI-VULV-1 cell line, obtained from a lymph node metastasis of an SCV, grows with a population doubling time of approximately 60 hr. The saturation density is 10(5) cells/cm2. The cell line does not exhibit anchorage independence and is weakly tumorigenic. The cells range in appearance from an abundant spindle cell to a less common larger, flat cell. All of the cells are immunoreactive for high-molecular-weight keratin, but only the flat cells, which form squamous pearls in vivo, are immunoreactive for low-molecular-weight keratin. The cell line expresses epidermal growth factor (EGF), transforming growth factor-alpha, the EGF receptor, and p53 protein. Polymerase chain reaction revealed no HPV DNA within the cells. Early passage cells exhibited karyotypic heterogeneity with few similarities to previous described SCV karyotypes. The cells display sensitivity to cis-platinum in concentrations toxic to many ovarian and cervical carcinoma lines. UCI-VULV-1 may be helpful for studying the properties of the HPV-negative form of SCV.
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PMID:UCI-VULV-1, a vulvar squamous carcinoma cell line. 772 33

Cervical cancer is not considered a hormone-responsive tumor in spite of the presence of estrogen receptors (ER) and progesterone receptors (PgR) in some of them. Endocrine treatments have not achieved clinical responses, however, tamoxifen has been reported to induce PgR and to inhibit cell growth of many cervical carcinoma cell lines. In this study we investigated whether tamoxifen administration affects the histopathological characteristics of cervical cancer and the expression of ER, PgR, HER-2/neu and p53 protein. Nineteen patients with invasive cervical cancer free of previous treatments were studied. The triphenylethylene antiestrogen tamoxifen was given orally during 10 days (20 or 40 mg/day). Pre- and post-tamoxifen biopsies were evaluated using slides stained with hematoxylin and eosin and immunostained (ER, PgR, HER-2/neu, p53, PCNA, keratin, heat shock protein 27,000 daltons). Estrogen receptors were present in 37% and PgR in 16% of the biopsies from untreated patients. Only one case that was PgR-negative before tamoxifen administration showed weak PgR-positivity following antiestrogen administration. No obvious changes were observed in ER, HER-2/neu and p53 proteins. A statistically significant decrease in the number of mitotic figures was obtained in 16% (3/19) of the post-tamoxifen biopsies and two of them showed higher differentiation. The results showed that tamoxifen did not induce changes in estrogen-regulated proteins in cervical cancer. However, the data showed that certain cervical carcinomas had changes in their proliferation and differentiation levels following tamoxifen administration. These findings suggest that tamoxifen may affect some cervical cancer tissues by a hormone-independent mechanism(s).
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PMID:Effects of short-term tamoxifen administration in patients with invasive cervical carcinoma. 790 50

Microwave oven (mwo) is used to stimulate tissue fixation and to retrieve antigens damaged by fixation. Heavy metal salt solutions, water, and citric acid buffer (cab) have been suggested for this purpose. A serie of tumors treated with cab and phosphate-buffered saline (pbs) with mwo were studied immunohistochemically with 24 antibodies. Controls were treated in the same way, except for microwaving. The antibodies were directed against antigens of the following tumors: breast and prostate carcinoma, carcinoid, lymphoma and melanoma. The results showed that cab enhanced the immunoreactivity of the following antigens: estrogen receptors (AMAC), progesterone receptors (Novocastra), HMB45, vimentin, leukocyte common antigen, PCNA, p53, MIB-1 (Ki-67) and prostatic specific antigen. The antigens that did not improve their immunoreactivity, when compared with the control series were: factor VIII, keratin, Leu 22, L26, neuron-specific enolase, CEA, chromogranin, HBME-1, smooth muscle actin and EMA. Microwaving equally improved protein S100 and desmin either with cab or pbs. The only antigen that improved with pbs was actin. The results with B72.3 and NKI/C3 were poor and not reliable. In conclusion microwaving with cab enhances the immunoreactivity of the antibodies mentioned above leading to an increase in sensibility without loosing specificity.
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PMID:[Antigen retrieval by microwave oven with buffer of citric acid]. 799 28

We recently described culture conditions that allow proliferation of metastatic human breast cancer cells from biopsy specimens of certain patient samples. These conditions resulted in the development of an immortalized cell strain designated SUM-44PE. These same culture conditions were used to isolate a human breast cancer cell strain from a metastatic lymph node of a separate breast cancer patient. The SUM-16LN human breast cancer cells isolated from this specimen were cultured either in serum-free medium or serum-containing medium supplemented with insulin and hydrocortisone. Unlike the SUM-44PE cells that have proliferated in culture continuously for over two years, SUM-16LN cells proliferated in culture for approximately 200 days and underwent 15 to 20 population doublings before undergoing cell senescence. No cells of this strain proliferated beyond passage 8. SUM-16LN cells were keratin-19 positive and had an aneuploid karyotype. These cells overexpressed p53 protein and had an amplified epidermal growth factor (EGF) receptor gene that resulted in high level expression of tyrosine phosphorylated EGF receptor protein. Despite the presence of high levels of tyrosine phosphorylated EGF receptor in these cells, they proliferated in serum-free, EGF-free medium and did not secrete detectable levels of EGF-like mitogenic growth factor. In addition, these cells were potently growth inhibited by all concentrations of exogenous EGF tested and by the neutralizing EGF receptor antibody Mab 425. These results suggest that the high level of tyrosine phosphorylated EGF receptor present in these cells is the direct result of receptor overexpression and not the result of the presence of a stimulatory ligand. Thus, SUM-16LN represents a human breast cancer cell strain that exhibited genetic and cellular characteristics of advanced human breast cancer cells. Nevertheless, these cells exhibited a finite proliferative lifespan in culture, suggesting that cellular immortalization is not a phenotype expressed by all human breast cancer cells.
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PMID:Finite proliferative lifespan in vitro of a human breast cancer cell strain isolated from a metastatic lymph node. 801 55

Pancreatoblastomas are rare tumours, which usually occur in childhood. Here we describe a pancreatoblastoma in a 39-year-old woman. The tumour was located in the tail of the pancreas and consisted of cells forming well-differentiated acinar structures and scattered solid components ("squamoid corpuscles"). Immunocytochemically, the acinar components were positive for pancreatic enzymes and pancreatic stone protein, while the cells of the "squamoid corpuscles" lacked these markers. There was no p53 overexpression nor any mutation at codon 12 of the Ki-ras oncogene. The main differential diagnosis of this tumour was acinar cell carcinoma, because both tumours have a number of features in common (scattered solid components, positivity for pancreatic enzymes, lack of p53 overexpression and of Ki-ras mutation). Findings which distinguished the pancreatoblastoma and separated it from acinar cell carcinoma were the negativity of the solid components ("squamoid corpuscles") for neuroendocrine markers and their very weak keratin positivity. As the patient is alive and well 30 months after tumour resection, this pancreatoblastoma also differs in biology from the usual acinar cell carcinoma.
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PMID:Pancreatoblastoma in an adult: its separation from acinar cell carcinoma. 803 29


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