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Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Normal human mammary epithelial cell (HMEC) cultures originating from 2 mammoplasty reduction surgical samples were transfected with replication-defective SV 40 DNA. Two independent cell lines designated as S2T2 and S1T3, selected for their increased proliferation potential and lifespan, were propagated for greater than 22 months in culture. They maintained a near-diploid karyotype with few chromosomal markers such as trisomy 1q (S1T3) and trisomy 8q (S2T2), which are most common in breast cancer in vivo. Immortalized S1T3 cells were not tumorigenic, whereas S2T2 cells produced slowly growing tumors in nude mice. One tumor was propagated in vitro and the transformed NS2T2 cell line subsequently raised 100% large tumors in the nude mouse. Rearrangement of the SV40 genome was observed in NS2T2 cells, which was not associated with increased expression of large T antigen. S1T3, S2T2 and transformed NS2T2 cell lines expressed cytokeratins CK18, CK19, the mammary-specific antigen DF3, and functional EGF receptors. Single-step immortalization and malignant transformation of human breast epithelial cells can thus occur upon transfection with SV40 large T oncogene. The chromosomal abnormalities observed in these cell lines suggest that they could offer a model for the study of breast-tumor progression in vitro.
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PMID:Single-steep transformation of human breast epithelial cells by SV40 large T oncogene. 132 42

The discrimination of atypical (premalignant) cells from invasive neoplastic cells in primary bladder lesions is a major diagnostic problem in cytopathology and surgical pathology. We have used an animal model of urinary bladder carcinogenesis to determine the specific changes which occur in the expression of certain cytokeratins (CK) during the progression of lesions from regenerative hyperplasia and carcinoma in situ to transitional cell carcinomas. At sequential time points following exposure of the rat bladder epithelium to N-methyl-N-nitrosourea in vivo, immunohistochemical staining of CKs was evaluated in ethanol-fixed samples from the induced urothelial lesions using commercially available anti-CK mouse monoclonal antibodies. Specific changes were found in the expression of CKs 13, 18, and 19 during the neoplastic progression of induced urothelial lesions in the rat. These changes included the reciprocal loss of expression of CK 19 and the reappearance of CK 18 as malignant tumors developed. Invasive cells also did not express CK 13. Our results, based on the rat model, are similar to those reported by others on CK expression in human bladder tumors. Because these changes in CK expression occurred at specific points in the progression of urothelial lesions, the antibodies utilized in this study may be helpful in predicting the invasive potential of cells present in cytopathological specimens and tissue biopsies from human urothelial lesions.
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PMID:Correlation of cytokeratin patterns with histopathology during neoplastic progression in the rat urinary bladder. 169 8

One hundred forty-one head and neck squamous cell carcinomas were analyzed for keratin (K) 6, 13 and 19. Staining was evaluated by light microscopy (with or without grading) and image analyzer and expressed as a percentage of positive versus all tumor surface (PSA). Both techniques rendered strongly correlated results. Strong expression was noted in 108 carcinomas (76.1%) for K6, in 18 (12.7%) for K19 and in 21 (14.8%) for K13 (P = .001). One hundred thirty-six (96%) tumors were positive for K6, and their PSA ranged from 0.6% to 48.8%; K19, 48 cases (0.2-44%); K13, 59 (0.2-38.1%). Expression of K6 was related to differentiation. K19 was expressed mainly in moderately and poorly differentiated tumors, and K13 was manifest more in well-differentiated carcinomas or in keratinized areas of less-differentiated ones. Nineteen (13.38%) tumors were positive for both K13 and K19. K19 thus was related to tumor progression and K13 to differentiation. There was no correlation with tumor site or TNM category.
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PMID:Keratins 6, 13 and 19. Differential expression in squamous cell carcinoma of the head and neck. 750 82

Cytokeratins, which comprise a multigene family of 20 related polypeptides (CKs 1-20), are constituents of the intermediate filaments of epithelial cells, in which they are expressed in various combinations depending on the epithelial type and the degree of differentiation. Of these, CK 19 (400 amino acids; 44.1 kilodaltons) is an example of a widely distributed CK, being expressed in various epithelia, including many simple epithelia. In contrast, the recently identified CK 20 (424 amino acids; 48.6 kilodaltons) is essentially confined to gastrointestinal epithelia, the urothelium and Merkel cells. The differential expression of individual CKs in various types of carcinomas makes them useful markers for histopathological carcinoma subtyping, providing relevant information concerning the differentiation and origin of carcinomas, especially when tumors first present as metastases. The CKs that are of particular value for differential diagnosis include CK 20, as it is mainly expressed in carcinomas derived from CK 20-positive epithelia; it is also found in bile-tract, pancreatic and mucinous ovarian adenocarcinomas, being absent in most other carcinomas. In certain carcinoma types, the changes in the expression of individual CKs that may occur during tumor progression could be of prognostic relevance. It remains to be established whether the serological detection of fragments of not only widely distributed but also more restrictedly expressed CKs may provide useful serological tumor markers in the future.
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PMID:Cytokeratins in the histological diagnosis of malignant tumors. 752 43

Transition from a normal to a cancerous state is marked by alterations in the cytoskeletal structure of those cells involved. We have examined such changes to determine if these transitions are markers of disease progression. Cytokeratin (CK) protein and messenger RNA (mRNA) expression were examined in malignant and benign breast tissues. Flow cytometric results demonstrated a significant correlation between cytokeratin protein expression detected by 5D3 antibody, specific for cytokeratins 8, 18, and 19 and axillary node metastasis (P = 0.01). A threshold of positivity of 338,000 molecules/cell was determined and reflected the wide range in cytokeratin levels expressed by normal or benign tissues. Examination of cytokeratins 8, 18, and 19 revealed a consistent pattern of expression with respect to tumor grade. Only cytokeratin 19 showed significant correlation with increasing tumor size (P = 0.006). mRNA expression for cytokeratin 8 was significantly higher in node-positive compared with node-negative disease (P = 0.02). Cytokeratin 18 mRNA levels were significantly lower in both node-negative (P = 0.03) and node-positive (P = 0.02) patients when compared with benign samples. Increased levels of cytokeratin 18 mRNA showed an inverse relationship with protein expression (P = 0.05). The results indicate that cytokeratin expression in breast cancer may be associated with tumor progression. Furthermore, the alteration in the expression of individual cytokeratins deserves further investigation to determine the consequences of these changes with respect to cellular function.
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PMID:Cytokeratin expression in breast cancer: phenotypic changes associated with disease progression. 970 99

The introduction of new regimens in the chemotherapy of inoperable non-small cell lung cancer (NSCLC) patients provides a useful extension of survival probability that may now justify the application of tumor markers for the disease monitoring. In a prospective study of 48 consecutive NSCLC patients with TNM stages IIIB/IV we compared changes in the serum levels of the cytokeratin 19 fragment CYFRA 21-1 with the clinical evaluations of response to therapy. CYFRA 21-1 levels were measured using the enzyme immunoassay of Boehringer, Mannheim (Germany). Clinical response to therapy was evaluated according to standard criteria of the WHO. For the assessment of response to therapy by changes in the marker levels the difference between two consecutive levels must exceed 30%. This value is based on the formula: Difference = 2 square root of 2 x CV (CV: inter-assay coefficient of variation of the marker test). CYFRA 21-1 was found to be elevated in 29/48 (60.4%) patients prior to therapy and in 10/48 (20.8%) patients at tumor progression. 91 evaluations have been recorded in these 39 patients. The overall concordance between changes in the marker levels and the clinical assessment was 59.3%. The decrease of CYFRA 21-1 levels at remission was rather low resulting in a concordance of only 42.9%, i.e. marker assays cannot replace the clinical restaging by imaging modalities. In contrast, changes in the marker levels at progression did exceed the required 30% in the majority of cases (64.7%). Most of discordant results (40.7%) could be explained by insufficient decrease or increase of CYFRA 21-1 levels or by extended lead-time. The most striking result was the detection of progressive disease by rising marker levels. Except one case, there was no false-positive elevation of CYFRA 21-1 levels. It is concluded that the detection of progressive disease by rising CYFRA 21-1 levels may avoid continuation of ineffective treatment.
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PMID:CYFRA 21-1 in the follow-up of inoperable non-small cell lung cancer patients treated with chemotherapy. 1047 Feb 17

Furan cholangiocarcinogenesis in rat liver is proving to be a unique and useful animal model for investigating important aspects of the cellular and molecular pathogenesis of cholangiocarcinoma potentially relevant to the human disease. We now describe the first culture model of rat cholangiocarcinoma cells derived from a transplantable cholangiocarcinoma originally induced in the liver of a furan-treated rat. An epithelial cell isolate highly enriched in viable cholangiocarcinoma cells was consistently obtained from transplantable cholangiocarcinoma tissue utilizing a similar procedure to that recently developed by us to establish a new rat hyperplastic bile ductular epithelial cell culture model characterized by the appearance of polarized bile ducts in vitro. Primary cholangiocarcinoma cell cultures could be readily established with these isolated cells and, in addition, we established from one such culture a novel rat cholangiocarcinoma cell line designated C611B. Cultured C611B cholangiocarcinoma cells retained a number of important characteristic features of the carcinoma cells of the parent tumor, including marked expression of the tyrosine kinase growth factor receptor proteins c-Met and c-Neu. Under basal culture conditions, the C611B cell line exhibited a cell doubling time of approximately 24 h and was aneuploid, with a predominant chromosomal count of 43. Moreover, C611B cells on collagen gels were 100% tumorigenic when transplanted into inguinal fat pads of syngeneic rats. All tumors formed at the transplantation site were cytokeratin 19-positive, mucin-producing tubular adenocarcinomas whose histological and phenotypic features closely resembled those of the furan-induced parent transplantable rat cholangiocarcinoma. Based on our findings, we believe that this novel rat cholangiocarcinoma cell culture model can serve as a valuable resource for investigating aberrant growth properties and tumor progression in biliary cancer.
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PMID:Establishment of a novel rat cholangiocarcinoma cell culture model. 1059 Feb 29

The tumor suppressor p53 transcriptionally regulates a large number of target genes that may affect cell growth and cell death pathways. To better understand the role of p53 loss in tumorigenesis, we have developed a mouse mammary cancer model, the Wnt-1 TG/p53 model. Wnt-1 transgenic females that are p53-/- develop mammary adenocarcinomas that arise sooner, grow faster, appear more anaplastic, and have higher levels of chromosomal instability than their Wnt-1 transgenic p53+/+ counterparts. In this study, we used several assays to determine whether the presence or absence of p53 affects gene expression patterns in the mammary adenocarcinomas. Most of the differentially expressed genes are increased in p53+/+ tumors and many of these represent known target genes of p53 (p21WAF/C1P1, cyclin G1, alpha smooth muscle actin, and cytokeratin 19). Some of these genes (cytokeratin 19, alpha smooth muscle actin, and kappa casein) represent mammary gland differentiation markers which may contribute to the inhibited tumor progression and are consistent with the more differentiated histopathology observed in the p53+/+ tumors. Several differentially expressed genes are growth regulatory in function (p21, c-kit, and cyclin B1) and their altered expression levels correlate well with the differing growth properties of the p53+/+ and p53-/- tumors. Thus, while tumors can arise and progress in the presence of functioning wild type p53, p53 may directly or indirectly regulate expression of an array of genes that facilitate differentiation and inhibit proliferation, contributing to a more differentiated, slow growing, and genomically stable phenotype.
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PMID:Differential gene expression in mouse mammary adenocarcinomas in the presence and absence of wild type p53. 1114 50

Recent studies point out that cytokeratins (CKs) are involved in dynamic cell remodeling during cancer progression and particularly, CK expression patterns have been associated with invasion and metastasis. In oesophageal squamous cell cancer (ESCC), lymph node (LNN) metastasis is an important step in disease progression, invariably associated with an ominous prognosis. To assess whether specific CK expression patterns could represent reliable markers of tumor progression, a series of 111 ESCCs (59 lymph node-positive, 52-negative) derived from the high- incidence area of Linxian (Northern China), were subjected to immunohistochemical (IHC) analysis with an extensive panel of CK antibodies. Statistically significant differences were observed for CK18 (p=0.01), CK19 (p=0.04) and PKK1 (p=0.02) expression between the LNN-negative and LNN-positive ESCCs. Furthermore, significant correlation between specific CK distribution pattern and progressive disease (i.e., LNN metastasis) was evidenced. The results suggest that CK8, CK18 and CK19 expression and distribution pattern could be of predictive value as a marker of disease progression as defined by the appearance of lymph node metastases in oesophageal squamous cell cancer.
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PMID:Cytokeratin expression patterns as an indicator of tumour progression in oesophageal squamous cell carcinoma. 1191 18

In cultured neuroblastoma cells, hypoxia induces a dedifferentiated phenotype. We tested whether hypoxia-induced dedifferentiation also occurs in vivo in mammary ductal carcinoma in situ with its well-defined lesions and distinct areas of necrosis. Ductal carcinoma in situ cells surrounding the central necrosis have high hypoxia inducible factor-1alpha protein levels, down-regulated estrogen receptor-alpha, and increased expression of the epithelial breast stem cell marker cytokeratin 19; lose their polarization; and acquire an increased nucleus/cytoplasm ratio, hallmarks of poor architectural and cellular differentiation. The hypoxia-induced changes were confirmed in cultured breast cancer cells. We propose that hypoxia-induced dedifferentiation is a mechanism that promotes tumor progression in breast cancer.
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PMID:Hypoxia promotes a dedifferentiated phenotype in ductal breast carcinoma in situ. 1267 Aug 86


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