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

The presence of colonic tumor cells in the circulation may predict colorectal carcinoma recurrence and metastases. We have developed a highly sensitive nested RT-PCR assay, with primers derived from the cytokeratin 20 (CK20) and the carcinoembryonic gene CGM2, to detect occult microdisseminated enterocytes in blood of colorectal cancer patients. Among 82 healthy controls analyzed, 40.2% (33/82) have a positive expression of CK20 mRNA which is not statistically different from the 45.5% (15/33) of positive results found in colon cancer patients. This sensitive method may detect non-tissue specific constitutive low level (illegitimate) expression of CK20 mRNA in peripheral nucleated blood cells (PNBC) of a significant number of healthy control as well as in a number of normal bone marrow. The low specificity of this assay therefore hampers its value to detect blood colon cancer dissemination. In 47 patients with colorectal carcinoma, CGM2 primers detected circulating enterocytes in 25 of them (53%). In disseminated Dukes' stage C disease patients, 17 out of 29 (59%) were found positive whereas in localized adenocarcinoma (Dukes's stage A and B), CGM2 primers detected enterocytes in 44% suggesting that an hematogenous spillage of colonic cells may be a relatively early event in colon cancer. None of the patients suffering from benign colonic pathologies or from diverticulitis were found positive for this assay. The analysis of 56 healthy individuals without known colorectal cancer, of 20 non-colorectal cancer patients and of 6 normal bone marrows provide evidence that this assay is highly specific and may predict an hematogenous spread of colonic cells in patients with organ-confined disease. Nevertheless, the clinical significance of enterocyte detection and the potential applications of this molecular tool merit longer term follow-up.
 ...
PMID:[Evaluation and interest in new molecular markers in colon cancer]. 977 30

Differential staining with cytokeratin (CK)-7 and CK-20, two members of a complex family of proteins in human epithelial cells, proved critical in showing that the extremely well-differentiated goblet-cell (intestinal) mucinous epithelium lining the surface of the endometrium and endocervix in two patients and the fallopian tube in one was identical to that of the coincident appendiceal neoplasms. One of these patients also had a large ovarian tumor that grossly and microscopically resembled a mucinous cystadenoma of borderline malignancy and would have been considered primary except for the CK stains (CK-20 positive and CK-7 negative), which suggested metastasis from the appendix, presumably by a transtubal route.
 ...
PMID:Goblet-cell mucinous epithelium lining the endometrium and endocervix: evidence of metastasis from an appendiceal primary tumor through the use of cytokeratin-7 and -20 immunostains. 978 38

We report a case of primary neuroendocrine carcinoma of the skin (PNECS) mimicking a lymphoepithelioma-like carcinoma of the skin (LELCS) with respect to both cytomorphology and the presence of a dense lymphoplasmacytic stroma. The tumor occurred in the left forearm of a 86-year-old woman, and its history was marked by aggressive behavior, with metastases to lymph nodes and to visceral sites within 1.5 years of diagnosis. The neoplastic epithelial cells had an immunophenotypic profile typical of PNECS, reacting for cytokeratin 20 and other low-molecular weight cytokeratins, neuron-specific enolase, neurofilament protein, synaptophysin, and chromogranin A. In addition, they were immunoreactive for epithelial membrane antigen, carcinoembryonic antigen, and S-100 protein, as observed in LELCS of supposed adnexal differentiation. The tumor-infiltrating lymphocytes were mostly of T-lineage, with a predominance of CD8+ cells. We believe the case is a morphologic variant of PNECS, retaining its aggressive behavior and high metastatic potential, and should not be confused with true LELCS, which has a more favorable outcome. Immunohistochemistry is paramount in establishing the diagnosis. Lymphoid infiltration, even if prominent, does not seem to be of favorable prognostic significance in such a context.
 ...
PMID:Neuroendocrine carcinoma of the skin with lymphoepithelioma-like features. 979 Jan 10

We describe a 60-year-old woman with leg pain. Although metastatic bone tumor and atypical cells mimicking signet-ring cells in the bone marrow picture were observed, systemic survey revealed no primary lesion. The patient died two months after admission from systemic progress of the disease. Autopsy revealed a small focus of adenocarcinoma within the right upper lobe of the lung and systemic metastases without any particular changes in the gastrointestinal tract. The tumor cells of the lung were diffusely positive for cytokeratin 7, whereas cytokeratin 20 immunoreactivity was weak and focal, and that supported the lung origin of the present tumor. Moreover, the tumor cells in the bone marrow showed a similar pattern in immunoreactivity. These findings suggest that cytokeratin 7 and cytokeratin 20 immunoreactivity is helpful for the premortem diagnosis of the metastatic tumor of unknown origin.
 ...
PMID:An autopsy case of cytokeratin 7-positive minute adenocarcinoma of the lung with systemic metastases. 980 85

Recombinant adenovirus (Adv)-mediated gene transduction is a powerful technology for cancer gene therapy. In this article, we report the generation of a fiber-mutant Adv vector, using the Adv genomic DNA-terminal protein complex (DNA-TPC) cotransfection method. First, a fiber-mutant construct in a plasmid carrying the right-side two-thirds of the human adenovirus type 5 (Ad5) genome (pTR) was cotransfected with Ad5 DNA-TPC, yielding the recombinant Adv with the desired fiber mutation. The DNA-TPC from the mutant Adv was then utilized to produce a second-step recombinant Adv with an expression cassette in the place of E1. By this procedure, we generated a fiber mutant, F/K20, that has a linker and a stretch of 20 lysine residues added at the C terminus of the fiber. By using Adv carrying a reporter lacZ gene (AxCAZ2) with either F/K20 or wild-type fiber (F/wt), we examined the transduction efficiency of F/K20-Adv. No significant difference in the transduction efficiency between F/K20 and F/wt-Adv was observed for a human fibroblast line, WI-38, or various tumor cell lines, including melanoma, prostate, esophageal, and pancreatic cancer lines. In clear contrast, F/K20-Adv showed a remarkably enhanced efficiency in genetic transduction of human glioma cells. In all four human glioma lines tested, the multiplicities of infection (MOIs) for transduction of 50% of the population (ED50) were decreased with F/K20-Adv compared with F/wt-Adv: 7-fold for T98G, 14-fold for U251, 9-fold for U373, and 42-fold for U87 cells. Therefore, we attempted to apply F/K20-Adv for gene therapy of malignant glioma. Glioma cells infected with F/K20-Adv carrying genes for interleukin 2 or interleukin 12 produced a high level of each cytokine at a much lower MOI than did cells infected with F/wt-Adv. Infection with F/K20-Adv carrying the wild-type p53 tumor suppressor gene resulted in an enhanced level of p53 protein expression and an increased incidence of F/K20-Adv in transduction efficiency for malignant glioma, providing promising tools for gene therapy.
 ...
PMID:Generation of fiber-mutant recombinant adenoviruses for gene therapy of malignant glioma. 985 17

We report a case of intraepidermal Merkel cell carcinoma which occurred on the face of a 76-year-old white male. This slow-growing tumor was mostly confined in the epidermis and pilosebaceous apparatus where tumor cells spread in a pagetoid fashion forming tumor cell nests. Histologically it resembled a superficial spreading melanoma. A heavy lymphocytic infiltration was seen beneath the epidermal lesion as is often seen in pagetoid melanomas. Histochemical and ultrastructural features such as the presence of cytokeratin 20, synaptophysin, neuron specific enolase, desmosomes, and dense cored granules confirmed the diagnosis of Merkel cell carcinoma. Occasional mitotic cells and many apoptotic cells were found in the tumor. Dylon positive, amyloid depositions were seen in the lower epidermis and papillary dermis; they were probably derived from apoptotic tumor cells. It was thought that apoptosis limited the speed of growth of this tumor. We believe that this is probably the most convincing case of intraepidermal Merkel cell carcinoma originating from epidermal Merkel cells or its precursors (stem cells).
 ...
PMID:Pagetoid Merkel cell carcinoma: epidermal origin of the tumor. 1048 94

Adenocarcinomas metastatic to brain from lung or colon may pose differentiation difficulties. Ultrastructurally, both may have brush borders with rootlets. This study examines the ultrastructural morphology and immunohistochemical expression of villin (associated with rootlets), cytokeratin 7 (present in lung adenocarcinomas), and cytokeratin 20 (present in colon adenocarcinomas) in 19 formalin-fixed sequential surgical biopsies of lung adenocarcinomas metastatic to brain as compared to 13 colonic adenocarcinoma metastases. Of lung tumor metastases, mucinous differentiation with rootlets was most common [6/19(32%)]. All colon tumor metastases were cytokeratin 7(-), 20(+), and profusely villin(+). Well-formed rootlets were seen. All lung metastases were cytokeratin 7(+) and 20(-). 5/6(83%) lung metastases with rootlets were focally villin(+). 12/13(95%) without rootlets were villin(-). Rootlets are extremely common in lung adenocarcinoma metastatic to brain. Villin immunoreactivity closely correlates with rootlets. Its distribution is a useful adjunct to cytokeratin 7 and 20 in differentiation of lung versus colon adenocarcinomas metastatic to the brain.
 ...
PMID:Lung adenocarcinomas metastatic to the brain with and without ultrastructural evidence of rootlets: an electron microscopic and immunohistochemical study using cytokeratins 7 and 20 and villin. 988 81

We studied the metastatic properties of human tumor cells and tumor cell dissemination in a xenograft tumor model for human colorectal carcinoma in athymic rats which shows a reproducible pattern of metastases similar to the clinical situation. Such a model is also attractive for evaluating several therapeutic approaches. The tumor cell lines HT-29 and WiDr which are derived from the same colorectal tumor and exhibit a similar tumorigenic potential after subcutaneous injection were injected into the portal venous system of 4-week-old male nude rats. After injection of WiDr cells no liver metastases were observed; however, 50% of the rats developed liver metastases 4-12 weeks after injection of HT-29. Immunostaining of the liver cryosections at different times after injection revealed a total disappearance of WiDr cells within the first 12 h. A subpopulation of HT-29 (HT29-b) with increased metastatic activity was isolated by double selection and recultivation of cells from induced liver metastases. After a 6- to 12-week period rats injected with HT-29b showed a pattern of metastases with additional lung metastases and in some cases peritoneal carcinosis. In addition to immunohistochemistry cytokeratin 20 reverse transcriptase-polymerase chain reaction was confirmed to be a sensitive and specific tool for the detection of disseminated tumor cells in different compartments.
 ...
PMID:A human carcinoma model in athymic rats reflecting solid and disseminated colorectal metastases. 992 49

This study was undertaken to assess the utility of combined cytokeratin (CK) 7/20 immunoprofile determination in malignant cytologic cell blocks as an aid to the identification of tumor primary site of origin. Fifty-one cases in which CK 7/20 immunocytochemistry was performed as part of the initial workup were retrieved. Their contribution to the final cytologic diagnosis of tumor primary site of origin was analyzed. CK reactivity patterns were 7+/20- (n = 34), 7-/20+ (n = 9), 7-/20- (n = 7), and 7+/20+ (n = 1). The CK 7+/CK 20- immunophenotype was the most common one obtained, and due to its wide expression in a number of common carcinomas, the least informative. The second most common immunophenotype was CK 7-/20+, which is associated with colorectal origin, and as such was very useful when obtained. The CK immunoprofile was more useful in the setting of a prior carcinoma, being a major diagnostic determinant in 13 cases (55%) from group 1 (those with a prior history of malignancy), compared to 8 cases (29%) from group 2 (those with no prior history of malignancy). In the setting of prior carcinoma, the CK immunoprofile is most useful when carcinomas under consideration have different expected immunoprofiles (e.g., CK 7+/CK20- carcinomas, including lung, breast, ovary, endometrium, and others, vs. CK 7-/CK 20+ carcinomas, primarily colorectal). When similar immunoprofiles are obtained, their usefulness is greater if they are immunoprofiles other than the most common 7+/20- pattern. Similarly, in newly diagnosed carcinomas, the CK immunoprofile either helps to narrow the differential diagnosis or points to a specific diagnosis.
 ...
PMID:Utility of cytokeratin 7 and 20 subset analysis as an aid in the identification of primary site of origin of malignancy in cytologic specimens. 995 98

Merkel cell carcinoma is an aggressive cutaneous neoplasm that is often difficult to diagnose because of its histologic and immunohistochemical similarity to metastatic oat cell carcinomas and other cutaneous neoplasms. Our purpose was to determine the utility of immunoperoxidase staining of cytokeratin 20 (CK 20), a newly discovered intermediate filament protein, in Merkel cell carcinomas and other cutaneous tumors. Sixty-one tumors were sectioned and stained with antibodies directed at CK 20. The staining of Merkel cell carcinomas was compared with metastatic oat cell carcinomas, lymphomas, squamous cell carcinomas, basal cell carcinomas, melanomas, metastatic carcinoids, spiradenomas, eccrine carcinomas, adenoidcystic carcinoma, sebaceous carcinomas, hidradenomas, sebaceous epitheliomas, trichoblastomas, mixed tumors, and metastatic adenocarcinomas. Nine of 10 Merkel cell carcinomas stained with antibody to CK 20. Two metastatic carcinomas to the skin were also positive. One hidradenoma and one squamous carcinoma exhibited focal staining, but were otherwise negative. All other tumors were nonstaining. Cytokeratin 20 is a sensitive and specific marker for Merkel cell carcinoma and is helpful in distinguishing between Merkel cell carcinoma and other malignant and benign neoplasms.
 ...
PMID:Cytokeratin 20: a marker for diagnosing Merkel cell carcinoma. 1002 19


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>