Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A tumor-associated antigen detected by monoclonal antibody UM-A9 raised against a cultured cell line from a patient with an aggressive SCC of the oral cavity has been defined. The A9 antigen is abnormally expressed in squamous cancers, with loss of basal polarization and increased intensity of expression distinguishing malignant from normal cells. A minority of cultured SCC cell lines and about one third of fresh tumors exhibit polarized A9 expression. The increased intensity and loss of polarized expression of A9 antigen in recurrent and metastatic tumor cell lines when compared with primary or early tumor cell lines from the same patients indicated an association of altered expression with tumor progression. When A9 expression was evaluated in frozen tumor sections, three patterns of expression representing increasing intensity and loss of polarization were observed. Patients whose tumors exhibited the most intense A9 antigen expression had a higher rate of early relapse than patients whose tumors exhibited low intensity and polar expression. Loss of blood group antigen expression was also associated with poor prognosis, and together high A9 antigen expression and loss of blood group defined a group of patients at high risk of early relapse. The A9 antigen is immunologically and biochemically identical to the alpha 6 beta 4 integrin. The association of high expression of the A9/alpha 6 beta 4 integrin as a prognostic factor is supported by similar findings with a mouse model system. The mouse tumor-associated antigen, TSP-180, which is also an alpha 6 beta 4 integrin, distinguishes highly metastatic tumor cells from nonmetastatic variants of the same tumor line. In SCC, the alpha 6 beta 4 integrin contributes to attachment to laminin since anti-alpha 6 subunit specific antibody blocks cell attachment and only the beta 4 subunit is found in association with the alpha 6 subunit in these cells. Similar findings were obtained in colon carcinomas. Antibodies and peptides that block laminin attachment may lead to the development of antimetastatic agents for squamous carcinomas. The beta 4 subunit is unique from other integrins in that it has an unusually long cytoplasmic domain, the function of which is not known. The beta 4 subunit is heavily phosphorylated under conditions that favor anchoring and terminal differentiation in normal keratinocytes. Paradoxically the beta 4 subunit is also heavily phosphorylated in tumor cells, which are highly migratory and immortalized.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Overexpression of the A9 antigen/alpha 6 beta 4 integrin in head and neck cancer. 138 8

The process of mouse skin tumor formation is subdivided into three operational stages. These stages include initiation, promotion and progression. Ionizing radiation has been found to be a weak initiating agent in the production of malignant squamous cell carcinomas, a complete carcinogen and an agent effective in causing tumor progression. Four skin tumor histologies have been seen with ionizing radiation: benign papillomas, squamous (SCC) and basal (BCC) cell carcinomas and fibrosarcomas. Distinct non-ras transforming genes have been detected in radiation initiated SCCs. A benign papilloma cell line (308) was used as a model system to study ionizing radiation induced progression. A variant 308 cell line (308 10 Gy 5) derived by irradiation of the parental 308 cell has been characterized. The 308 10 Gy 5 cells unlike the parental 308 cells form malignant tumors in athymic nude mice upon subcutaneous injection. The variant 308 10 Gy 5 cells unlike the parental cells also show by northern analysis high steady state levels of the following gene transcripts: stromelysin, metallothionein II A and the proto-oncogenes c-fos and c-jun. Transient transfection studies with a chimeric mouse stromelysin promoter sequence upstream of a chloramphenicol (CAT) reporter gene into 308 and 308 10 Gy 5 cells indicated that the stromelysin promoter was constitutively active in the 308 10 Gy 5 but not in the 308 cells. The ability to divide the process of carcinogenesis into multiple stages in the mouse skin mode has facilitated mechanistic studies that may elucidate the molecular pathways involved in radiation induced tumor development.
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PMID:Molecular events involved in ionizing radiation induced skin carcinogenesis. 182 59

Many human tumors contain variant cells that, unlike their normal counterparts, possess indefinite proliferative potential in vitro. However, little is known of the relevance of these immortal cells to human carcinomas in vivo. To investigate immortality in a human tumor system, we established cultures from different stages of head and neck squamous carcinoma (SCC-HN). All the neoplastic cultures were transformed because they showed very low cornification in surface or suspension culture and were partially or completely resistant to suspension-induced death. Immortal variants were not detected in premalignant erythroplakia cultures, but their frequency increased with tumor progression, indicating that immortality is a late event in carcinogenesis. Some late-stage carcinomas still produced senescent cultures, but, significantly, all recurrent tumors were immortal. Immortal but not senescent carcinoma cultures were associated with p53 dysfunction and a high frequency of allele loss, indicative of tumor suppressor gene inactivation. These results show that there are at least two classes of human SCC-HN that are phenotypically and genotypically distinct and that the pathological stage of a given tumor is not necessarily indicative of the kind of cells it contains.
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PMID:Cellular immortality: a late event in the progression of human squamous cell carcinoma of the head and neck associated with p53 alteration and a high frequency of allele loss. 764 64

We investigated the frequency and clinical significance of loss of heterozygosity (LOH) at the APC, MCC, and DCC tumor suppressor gene loci in 108 cases of resected non-small cell lung cancer (NSCLC). LOH at the APC/MCC gene cluster at chromosome 5q21 occurred frequently; it affected 29% of informative NSCLC cases and correlated with a significantly worse survival (P < 0.01). Furthermore, in the subtype most frequently affected (SCC), LOH at 5q not only correlated with a worse survival but also tumor involvement of the mediastinal and/or hilar nodes. In contrast, LOH at the DCC locus at chromosome 18q was far less frequent, occurring in 14% of NSCLC cases, and it was not associated with advanced stage or prognosis. These data suggest that LOH at 5q has a role in determining tumor progression and survival in NSCLC, and may prove to be a clinically useful prognostic indicator.
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PMID:Tumor progression and loss of heterozygosity at 5q and 18q in non-small cell lung cancer. 781 47

The majority of basal cell (BCC) and squamous cell (SCC) carcinomas of the skin are curable by surgery and/or radiation. However, additional therapy is required when the tumor is locally advanced, or has metastasized. 4 men and 4 women (mean age 70, range 49-86) with advanced BCC and/or SCC were treated with cisplatin-based chemotherapy. The disease was local in 4, local with regional lymph node involvement in 2, involved regional lymph nodes in 1 and was local with distant metastases in 1 patient. All were treated with a combination of cisplatin and 5'-fluorouracil. 2 were treated in addition with a combination of cyclophosphamide, doxorubicin, and cisplatin (CAP). Complete pathological response was seen in 2/8 and partial response in 4/8 with an overall response rate of 75%. There was tumor progression in 2. Survival of patients who responded was from 3-47 months (mean 12). The 2 who did not respond to chemotherapy died within 1 and 3 months of treatment. Significant side-effects in 6 included myelotoxicity and transient renal toxicity. We conclude that chemotherapy is effective in advanced BCC and SCC of the skin and may have curative potential when combined with local therapy.
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PMID:[Cisplatin-based chemotherapy for advanced basal and squamous cell carcinomas]. 781 42

In the clinical practice of lung cancer, serum tumor markers are important laboratory tests and their use is wide spread. Among the various markers for lung cancer, the usefulness of CEA, SLX, SCC and NSE has been firmly established. These markers cannot be used routinely to screen for lung cancer but may be used as complementary tools for diagnosing the tumor. Elevated levels of these markers also appear to be useful for monitoring the response to therapy and tumor progression. CYFRA21-1 and ProGRP, new tumor markers with relatively high sensitivity and specificity to lung cancer, were recently developed. These tumor markers may be useful tools for early detection of lung cancer.
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PMID:[Usefulness and limitation of serum tumor markers in diagnosis of lung cancer]. 869 17

Cells in tumors may be exposed to adverse conditions such as nutrient deprivation, acidic pH and hypoxia. It has been shown previously that exposure to hypoxia, acidosis and glucose starvation in vitro increases the experimental metastatic ability of murine KHT-LP1 sarcoma, SCC-VII squamous carcinoma and B16 melanoma cells. This effect was most marked when cells were allowed to recover under normal in vitro growth conditions before injection. In the present study we examined whether the invasive capacity of the cells could be influenced by these modifications of the cell microenvironment. We used Matrigel, a basement membrane-like preparation in a two-chamber invasion assay to address this issue. Both KHT-LP1 and SCC-VII murine cell lines showed an increased ability to invade through Matrigel after hypoxia, and glucose starvation, but there was no consistent change in invasive capacity following acidosis exposure. The results for hypoxia and glucose starvation are in agreement with our previous studies of metastatic ability for these cell lines and we confirmed this for KHT-LP1 cells exposed to hypoxia in the current study. In parallel with the invasion assays, we compared cathepsin (L + B) content of the cells in treated and control suspensions. The effect observed varied according to the cell line and the treatment received (hypoxia, glucose starvation). There was an increase of cathepsin content for KHT-LP1 cells exposed to hypoxia and this increase correlated well with the increase of the invasion ability through Matrigel. We did not observe any increase of cathepsin for hypoxia-treated SCC-VII or for KHT-LP1 and SCC-VII cells treated with glucose starvation. These results suggest that transient hypoxia and glucose starvation can increase the invasive ability of tumor cell lines and thus may cause tumor progression by facilitating the invasive step of the metastatic process. The increased levels of cathepsin (L + B) in the KHT-LP1 cells treated with hypoxia, compared to control non-treated cells, may play a part in this increased invasive capacity.
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PMID:Exposure to hypoxia, glucose starvation and acidosis: effect on invasive capacity of murine tumor cells and correlation with cathepsin (L + B) secretion. 900 2

Nuclear receptors for retinoic acid are important modulators of epidermal cell proliferation and terminal differentiation. Aberrant expression of retinoic acid receptors (RARs) and retinoid X receptors in the epidermis has been associated with altered differentiation capacity and tumor progression. In this study, we describe a human squamous cell carcinoma line, SCC 12F, which displays reduced RARgamma expression and diminished responsiveness to retinoic acid. When compared with normal keratinocytes or other squamous cell carcinoma lines that display normal levels of RARgamma, several measures of cellular response to retinoic acid are altered in SCC 12F cells, including inhibition of cornified envelope formation, reduction of involucrin mRNA expression, and transcriptional regulation of the involucrin gene. Normal patterns of ligand-dependent transcriptional response were restored upon co-transfection of an expression vector containing either RARalpha or RARgamma. Our findings demonstrate that reduced expression of RAR may have direct functional consequences with regard to keratinocyte differentiation and that the defect may be alleviated by reintroduction of functional receptor.
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PMID:Functional consequences of reduced retinoic acid receptor gamma expression in a human squamous cell carcinoma line. 905 91

Photochemotherapy employing 8-methoxypsoralen and long-wavelength ultraviolet radiation (UVA, 320-400 nm) is widely used in the treatment of psoriasis. The photoactivation of psoralens in skin cells leads to formation of DNA photoadducts which may be responsible, at least in part, for the efficacy of these photochemotherapies. However, mutations arising from these adducts may also lead to the well-characterized increased incidence of squamous cell carcinoma. Mutations in the p53 tumor suppressor gene have been detected in many human cancers. To determine whether p53 mutations occur in squamous cell carcinomas in PUVA patients, PCR was used to amplify the exons (5-9) in which other studies have found a high frequency of point mutations. Gel electrophoresis was used to detect single-strand conformational polymorphisms. Aberrantly migrating bands were excised, reamplified and sequenced. Thirty-four specimens from 10 patients were examined. Specimens from one patient who had received no phototherapy as well as from normal controls were also analyzed. Five of the 10 patients showed at least one p53 mutation. In contrast to previously reported psoralen-induced p53 mutations in mice, the expected psoralen type mutations at alternating AT sites were not detected. All but two of the altered sequences occurred at dipyrimidine sites which is typical of solar type mutations. Two C-->T mutations and two dipyrimidine mutations (CC-->TT) were found. Other mutations included: C-->G, G-->T, C-->A and an 18 bp deletion. A review of therapeutic history of these patients showed that some had also received UVB phototherapy. Furthermore, because sunlight is thought to be beneficial for psoriasis, nontherapeutic, casual UVB exposure cannot be excluded. Our observations suggest that the SCC may have arisen from the solar mutations and that PUVA may enhance tumor progression or immune suppression.
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PMID:An unexpected spectrum of p53 mutations from squamous cell carcinomas in psoriasis patients treated with PUVA. 927 51

Tumor behavior is the result of specific genetic changes that alter gene expression. From our cytogenetic studies chromosome 18 loss emerged as a common genetic change in squamous carcinoma cell lines. In this report we summarize data that link loss of 18 to tumor progression and reduced survival, indicating that one or more tumor suppressor gene(s) are located on this chromosome. Tumors grown in vitro were karyotyped either as short-term or permanent cultures. Loss of chromosome 18 was measured by karyotype, decreased frequency of heterozygosity at the DCC locus, and loss of heterozygosity (LOH) for microsatellite repeat polymorphisms (MSRP). Loss of any part of chromosome 18 was observed in approximately 63% of cultured tumors. Primary and secondary tumors from the same individuals sometimes differed in loss of 18 indicating that this genetic change is associated with tumor progression. Heterozygosity for DCC was present in only 3/19 cultured SCC (16%), compared with 68% (11/16) of blood samples from unrelated donors, which is consistent with LOH in roughly one half of the cases. Of 4 informative cases with normal and tumor tissue, LOH was observed in 2. Microsatellite analysis also shows loss of 18q in 55% of fresh tumors. Analysis of tumor tissue and cell lines from the same patient gave identical results. There was an excess of deaths from cancer in the group with 18 loss (20/25) when compared with the group without (5/15). Loss of chromosome 18 appears to be a marker of tumor progression in SCC. It is likely that mutation affecting DCC or another gene on 18 affects tumor growth or spread, leading to more rapid progression and reduced survival.
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PMID:Identifying genetic changes associated with tumor progression in squamous cell carcinoma. 928 18


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