Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A major obstacle in understanding the etiology of malignant melanoma is the lack of mouse models and transplantable cell lines. We have recently developed a model of primary melanoma in C3H mice induced by ethanol and UV light. The present study characterizes three cell lines, SM190.2, SM190.626, and SD0302, derived from two melanomas produced in the dorsal skin of two C3H mice treated thrice weekly for 28-33 weeks with UV radiation and ethanol. In both tumors, the N-ras oncogene was mutated. Tumor SM190 lacked exon 2 of the p16(INK4a) tumor suppressor gene. Cell line SM190.2, which was derived from tumor SM190, produced pigmented tumors when transplanted into syngeneic severe combined immunodeficient mice and normal mice. None of the cell lines produced metastases. All three cell lines were highly aneuploid, even at low passage numbers. SM190.2 and SD0302 cells contained an interstitial deletion in the long arm of chromosome 4, where the p16(INK4a) gene resides, and SM190.2 had an additional segment in chromosome 6. The third cell line, SM190.626, had three consistent Robertsonian translocation markers involving chromosomes 7, 14, and 17. The translocation involving mouse chromosome 14 may prove especially valuable because translocations in this chromosome are associated with metastatic behavior. These reagents will provide opportunities to search for new tumor suppressor genes that may contribute to the growth and metastasis of primary melanoma.
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PMID:Molecular characterization of new melanoma cell lines from C3H mice induced by ethanol plus ultraviolet radiation. 1283 34

Homozygous deletions of human chromosomal region 9p21 occur frequently in malignant melanoma and are associated with the loss of the tumor suppressor genes p16(INK4a) and p15(INK4b). In the same chromosomal region the methylthioadenosine phosphorylase (MTAP) gene is localized and therefore may also serve as a tumor suppressor gene. The aim of this study was to analyze MTAP mutations and expression patterns in malignant melanomas. To examine the MTAP gene and expression of MTAP protein we screened 9 human melanoma cell lines and primary human melanocytes by reverse transcriptase-polymerase chain reaction, sequencing, and immunoblotting. Analyzing the melanoma cell lines we found significant down-regulation of MTAP mRNA expression. In only one cell line, HTZ19d, this was due to homozygous deletion of exon 2 to 8 whereas in the other cell lines promoter hypermethylation was detected. MTAP expression was further analyzed in vivo by immunohistochemical staining of 38 tissue samples of benign melanocytic nevi, melanomas, and melanoma metastases. In summary, we demonstrate significant inverse correlation between MTAP protein expression and progression of melanocytic tumors as the amount of MTAP protein staining decreases from benign melanocytic nevi to metastatic melanomas. Our results suggest an important role of MTAP inactivation in the development of melanomas. This finding may be of great clinical significance because recently an association between MTAP activity and interferon sensitivity has been suggested.
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PMID:Characterization of methylthioadenosin phosphorylase (MTAP) expression in malignant melanoma. 1287 87

Besides well-known risk factors such as tobacco use and alcohol consumption, oncogenic human papillomavirus (HPV) infection also has recently been suggested to promote head and neck tumorigenesis. HPV is known to cause cancer by inactivation of cell cycle regulators p53 and pRb via expression of viral oncoproteins E6 and E7. This indicates that p53 mutations are not a prerequisite in HPV-induced tumor development. However, discrepancy exists with respect to the frequency of head and neck squamous cell carcinomas (HNSCC) harboring DNA of oncogenic HPV and the fraction of these tumors showing p53 mutations. In our study, we examined the frequency of HNSCC demonstrating HPV 16/18 integration as identified by fluorescence in situ hybridization (FISH) and investigated their p53 (mutation) status by immunohistochemistry and single-strand conformation polymorphism (SSCP) analysis of exons 5-8. Paraffin-embedded, archival biopsy material from 27 premalignant mucosal lesions and 47 cases of HNSCC were analyzed. Ten of the 47 (21%) HNSCC unequivocally exhibited HPV 16 integration, including 8 of 12 (67%) tonsillar carcinomas. This is supported by the immunohistochemical detection of p16(INK4A) overexpression in all 10 HPV-positive tumors. Although FISH is considered to be less sensitive than PCR-based methods for HPV detection, our data clearly demonstrate clonal association of HPV with these tumors, as illustrated by the presence of integrated HPV 16 in both the primary tumor and their metastases in 2 patients. In contrast, HPV 16/18 DNA could not be detected in the premalignant lesions. In 30 of 47 (64%), HNSCC accumulation of p53 was observed, including 8 of the 10 HPV-positive carcinomas. However, in none of the latter cases could mutations in exons 5-8 be identified, except for a polymorphism in codon 213 of exon 6 in one patient. Evaluation of clinical data revealed a significant inverse relation between tobacco use with or without alcohol consumption, and HPV positivity of the tumors.
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PMID:A subset of head and neck squamous cell carcinomas exhibits integration of HPV 16/18 DNA and overexpression of p16INK4A and p53 in the absence of mutations in p53 exons 5-8. 1450 39

Upon the introduction of extensive sampling protocols of sentinel node biopsies, pathologists are increasingly confronted with small melanoma metastases. Using conventional histology, it proves sometimes difficult or impossible to differentiate small melanoma metastases from lymph-node nevi. Loss of the tumour suppressor gene p16 has been shown to be associated with tumour progression of melanoma. We investigated nevus and melanoma cells for the presence of the product of the gene p16, using immunohistochemistry. All nevus cells, independent of their location (nodal or skin) displayed an extensive nuclear and cytoplasmic staining for p16. In contrast, all cells of melanoma metastases, except one skin metastasis, lacked nuclear staining for p16. These findings indicate that p16 is a reliable marker to distinguish lymph-node nevi from melanoma metastasis.
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PMID:Immunostaining for the tumour suppressor gene p16 product is a useful marker to differentiate melanoma metastasis from lymph-node nevus. 1457 37

Most colorectal carcinomas (CRCs) arise from adenomas through an archetypal pathogenic pathway, the adenoma-carcinoma-metastasis sequence. Aberrant expression of beta-catenin, p16, E-cadherin and c-myc appears to have played important roles in the development and/or progression of CRC, but their precise distribution pattern and associations in different pathologic loci along CRC's pathogenic pathway have not been thoroughly examined. In this study, a tissue microarray (TMA) containing 85 advanced CRCs in different Dukes stages was constructed. In each of 85 cases, tissue specimens from normal mucosa and primary carcinomas in different layers of the bowel wall were included in the TMA. Tissue specimens from matched adenoma, lymph node metastases and distant metastases were obtained from 22, 21 and 21 cases, respectively. Expression patterns of beta-catenin, p16, E-cadherin and c-myc were evaluated by immunohistochemistry. The results revealed that nuclear expression of beta-catenin, p16 and c-myc was quantitatively increased from normal mucosa to premalignant adenoma, primary carcinoma and lymph node metastatic carcinoma; the frequency of nuclear overexpression of beta-catenin and p16 in lymph node metastases was significantly higher than that in distant metastases (p < 0.05). These results suggest an association between nuclear overexpression of beta-catenin and/or p16 and CRC lymph node metastasis but not distant metastasis. The results also showed that correlative high nuclear expression of beta-catenin and c-myc was observed in primary carcinomas involving the serosa and lymph node metastases (p < 0.05) but not in other pathologic regions of CRCs, suggesting that the tumor microenvironment in different pathologic loci of colorectal tumorigenesis and progression may influence c-myc responsiveness to beta-catenin/Tcf activation.
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PMID:Heterogeneous expression and association of beta-catenin, p16 and c-myc in multistage colorectal tumorigenesis and progression detected by tissue microarray. 1460 Oct 48

The retinoblastoma (Rb) pathway controls the G1-S checkpoint of the cell cycle. Inactivating mutations and deletions of p16 and Rb and up-regulation of cyclin D1 disrupt this pathway and occur in many cancers. However, the concurrent expression of these genes in primary and metastatic gastric cancer is unknown, and the prognostic value of their expression is unclear. In this study, the expression of cyclin D1, retinoblastoma protein (pRb), and p16 in 67 resected gastric adenocarcinomas, and of pRb and p16 in 40 associated lymph node metastases, was determined using a streptavidin-biotin-peroxidase immunohistochemical method. Relationships with clinical and pathological features were analyzed. Cyclin D1 overexpression (>/=5% expression) was seen in 55% of cancers; pRb loss (<20% expression), in 33%; p16 loss (<10% expression), in 49%; and at least 1 of these abnormalities, in 92.5%. Cyclin D1 overexpression was associated with poor differentiation (P = 0.027) and signet ring cell type (P = 0.029). pRb expression was lower in lymph node metastases than in the corresponding primary tumors (P <0.001). Univariate and multivariate survival analysis (minimum follow-up 72 months or until death) revealed that <20% pRb expression, <30% pRb expression, and International Union Against Cancer stage >2 were associated with worse overall survival. The results suggest that Rb pathway disturbances play an important role in gastric carcinogenesis. The poor prognosis of cancers with low pRb expression and the reduced pRb expression in lymph node metastases raise the possibility that Rb and related genes also influence progression.
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PMID:Abnormal expression of pRb, p16, and cyclin D1 in gastric adenocarcinoma and its lymph node metastases: relationship with pathological features and survival. 1469 13

Cutaneous malignant melanoma remains the leading cause of skin cancer death in industrialized countries. Clinical and histological variables that predict survival, such as Breslow's index, tumor size, ulceration, or vascular invasion have been identified in malignant melanoma. Nevertheless, the potential relevance of biological variables still awaits an in-depth exploration. Using tissue microarrays (TMAs), we retrospectively analyzed 165 malignant melanoma samples from 88 patients corresponding to distinct histological progression phases, radial, vertical, and metastases. A panel of 39 different antibodies for cell cycle, apoptosis, melanoma antigens, transcription factors, DNA mismatch repair, and other proteins was used. Integrating the information, the study has identified expression profiles distinguishing specific melanoma progression stages. Most of the detected alterations were linked to the control of cell cycle G1/S transition; cyclin D1 was expressed in radial cases 48% (12 of 25) with significant lost of expression in vertical cases 14% (9 of 65), P = 0.002; whereas p16(INK4a) (89% in vertical versus 71% in metastatic cases, P = 0.009) and p27(KIP1) (76% in radial versus 45% in vertical cases, P = 0.010) were diminished in advanced stages. The study also defines a combination of biological markers associated with shorter overall survival in patients with vertical growth phase melanoma, that provided a predictor model with four antibodies (Ki67, p16(INK4a), p21(CIP1), and Bcl-6). This predictor model was validated using an independent series of 72 vertical growth phase melanoma patients.
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PMID:Progression in cutaneous malignant melanoma is associated with distinct expression profiles: a tissue microarray-based study. 1469 33

Melanoma prognosis is based on histological criteria such as tumor thickness (measured by Breslow index), level of invasion (Clarck's level), presence of ulceration and number of mitoses per mm2. However, these parameters do not provide a precise prognosis in all cases: thin melanomas may develop metastases and thick melanomas may remain focalized for many years. For these reasons, the search for other prognostic factors is still ongoing. Many molecules play a part in the invasiveness and metastatic dissemination of melanoma have now been identified. Expression of these molecules has been studied in primary melanoma and correlated with prognosis. An increase in the number of cells positive for Ki67 (detected by Mib1), cycline A, cycline D, p35, MMp-2, beta1 and beta3 integrins, osteonectin, the presence of an intense inflammatory infiltrate and capillary invasion are considered as factors of poor prognosis as well as the decrease in p16, p27, Melan A and nm23. The significance of CD44 modifications is still controversial. Only a small number of these different proteins has a prognostic value independent of tumor thickness. These results need to be confirmed on larger series of patients. Additional hope is given to new techniques such as the analysis of the genes implied in tumor progression by microarray technique in such a way as to provide a molecular map of each tumor.
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PMID:[Molecular markers associated to prognosis of melanoma]. 1472 37

To evaluate the mutational profiles associated with BRAF mutations in human melanoma, we have studied BRAF, RAS, PTEN, TP53, CDKN2A and CDK4 genes and their expression in melanoma lesions. Owing to the lack of sufficient material from fresh specimens, we employed short-term cell lines obtained from melanoma biopsies. In all, 41 melanoma obtained from eight primary lesions, 20 nodal, 11 cutaneous and two visceral metastases from patients with sporadic (n=31), familial (n=4) and multiple melanoma (n=2) were analysed. The results revealed novel missense mutations in the BRAF, PTEN, CDKN2A and CDK4 genes. Overall, activating mutations of BRAF and loss of functional p16 and ARF were detected in the majority of melanomas (29/41, 36/41 and 29/41, respectively), while PTEN alterations/loss, NRAS and TP53 mutations occurred less frequently (6/41, 6/41 and 10/41, respectively). In the resulting 12 mutational profiles, p16/ARF loss associated with mutated BRAFV599E was the most represented (n=15). In addition, TP53 and PTEN mutations were always accompanied with BRAF alterations, while PTEN loss was found in association with CDKN2A or TP53 mutations in the absence of BRAF activation. The p16/ARFDelta+BRAF/RAS profile was significantly associated with a longer survival, while complex mutational profiles were detected in highly aggressive disease and poor survival. These data support the existence of several molecularly defined melanoma groups which likely reflect different clinical/biological behaviour, thus suggesting that a more extensive molecular classification of melanoma would significantly impact its clinical management.
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PMID:BRAF alterations are associated with complex mutational profiles in malignant melanoma. 1519 37

This paper reviews some aspects of the application of immunohistochemistry in gynaecological pathology. The use of cytokeratins 7 and 20 are discussed with reference to applications in ovarian pathology, including metastatic disease to the ovaries. Developments in utilising MIB-1 and p16 in cervical squamous and glandular lesions are discussed. Recent assertions regarding the differential diagnosis between endocervical and endometrial carcinomas are also reviewed. Antibodies that may be of use in the diagnosis of uterine mesenchymal and ovarian tumours are highlighted, as are antibodies of use in trophoblastic lesions including the use of p57 in evaluating hydatidiform moles.
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PMID:Immunohistochemistry in gynaecological pathology: a review. 1520 46


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