Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0677930 (primary tumor)
 20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epidemiological and experimental investigations have led to the hypothesis that the growth of malignant melanoma is induced by hormones. The demonstration of free-hormone binding sites in melanoma tissue may help to determine the validity of this hypothesis, as receptors are necessary for the transformation of hormonal action. The DCC assay with subsequent saturation analysis was used for the demonstration of specific cytoplasmatic binding sites of steroid hormones. The presence of free-cytosolic estrogen-, progesterone- and glucocorticosteroid receptors was investigated in 50 melanoma samples from 46 patients. In 20 of the 50 specimens, free estrogen and progesterone receptors were found. Free-glucocorticosteroid receptors we found in 10 cases. The use of four fold-labeled estradiol (2,4,6,7-[3]-17 beta-estradiol) in the DCC assay produced a false-positive demonstration of free-estrogen receptors. Tyrosinase hydroxylates estradiol at the C2 level of the steroid. Using fourfold labeled estradiol, tritium is separated at the C2 position, thus forming radioactive water in the cytosol which mimics high, free-estrogen binding sites. The use of twofold-labeled estradiol or L-dopa in the experiments with fourfold labeled estradiol produced no false-positive determinations of estrogen receptors. The demonstration of receptors in malignant melanomas was unaffected by the sex of the patient. Also, the type of malignant melanoma, the invasion level, and the prognostic index did not show a correlation with the presence of the various hormone receptors. In metastases, free steroid hormone receptors were detected less often than in the primary tumor.
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PMID:[Steroid receptors in malignant melanomas]. 393 Apr 22

A human papillomavirus (HPV) type 16 containing oral squamous cell carcinoma cell line 93VU147T at early passage was demonstrated to match its primary tumor with regard to HPV status and loss of heterozygosity at loci potentially involved in HPV-mediated carcinogenesis. DNA in situ hybridization of the cell line and the primary tumor revealed the presence of HPV 16 DNA clonally associated with the neoplastic cells. One- and two-dimensional Southern blot hybridization suggested HPV 16 to be integrated in the host genome at over hundred copies/cell. An identical restriction enzyme profile was observed for the tumor and the cell line. Viral DNA integration was confirmed by fluorescence in situ hybridization on metaphase spreads of the cell line, which revealed six stained loci comprising one at 15q14-15 and five at cytogenetically unidentifiable chromosomes. In addition, the tumor and the cell line displayed mRNA expression of the E6/E7 region encoding the viral oncoproteins, as determined by reverse transcription-PCR. Northern blot analysis of the cell line revealed three major and three minor transcripts harboring E6/E7 sequences. Both the primary tumor and cell line showed loss of heterozygosity at the 11q22 (D11S35) and 18q21 (DCC) loci. These data support a role for HPV 16 in the development of a subset of oral cancers, presumably in concert with loss of function of tumor suppressor genes at 11q and 18q.
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PMID:Integrated human papillomavirus type 16 and loss of heterozygosity at 11q22 and 18q21 in an oral carcinoma and its derivative cell line. 758 17

Since tumor suppressor gene DCC exhibits amino acid sequence homology to the neural cell adhesion molecule, there is a possibility that DCC might be related to tumor metastasis. In the present study, we examined 51 cases of primary esophageal carcinomas with regard to point mutations and loss of the DCC gene. We detected point mutations in two cases by screening using polymerase chain reaction-single strand conformation polymorphism analysis. When we determined the sequences, one case with lymph node metastasis showed an ATG (Met) to ACG (Thr) missense mutation in codon 168. Another case showed a CGA (Arg) to GGA (Gly) mutation in codon 201, which might be a polymorphic change, and two other mutations resulting in no amino acid change. We also examined loss of heterozygosity of the DCC gene. Forty-four of the 51 cases (86%) were informative, and among them 10 cases (23%) showed allelic deletion. The further away the lymph node metastasis was from the primary tumor, the higher the frequency of allelic deletions became. We also found allelic deletions in moderately and poorly differentiated squamous cell carcinomas but not in well differentiated ones. These results indicate that alterations of the DCC gene are related to the degree of lymph node metastasis and the degree of differentiation.
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PMID:Point mutations and allelic deletion of tumor suppressor gene DCC in human esophageal squamous cell carcinomas and their relation to metastasis. 818 90

Four sets of cell lines (UM-SCC-14A, -14B, and -14C; UM-SCC-17A and -17B; UM-SCC-81A and -81B; and UM-SCC-83A and -83B), established from primary and metastatic or locally recurrent tumors from four patients with squamous cell carcinoma of the head and neck, were examined for loss of heterozygosity (LOH) on chromosome 18q. Metastatic or recurrent cell lines from all four exhibited 18q LOH. UM-SCC-14A, -14B, and -14C, which were derived from locally recurrent (14A and 14B) and metastatic (14C) tumors, lost all of 18q. However, in the other three cases, there was a partial loss of 18q in the recurrent or metastatic tumor cell lines but not in the primary tumor cell lines from the same patient. To determine whether the cell lines accurately reflect in vivo loss of 18q, we analyzed matched sets of normal, tumor, and tumor cell line DNA from eight patients with squamous cell carcinoma of the head and neck, including the tumor tissue corresponding to UM-SCC-81B. Three of the additional seven tumors and cell lines had 18q LOH. For all eight cases in which tumor and corresponding cell line DNAs were analyzed, there was complete concordance between allelic loss in the tumor and allelic loss in the corresponding cell line. The common region of loss established by tumors and cell lines with partial loss includes 18q21-18qter. This region contains the putative tumor suppressor gene DCC and two Mad (Mothers against dpp)-related genes, DPC4 and MADR2, which are both components in a transforming growth factor-beta-like signaling pathway. Loss of 18q in metastatic and locally recurrent tumors, but not in primary tumors from the same patients, suggests that a tumor suppressor gene in this region may be important in the progression of squamous cell carcinoma.
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PMID:Evidence that loss of chromosome 18q is associated with tumor progression. 904 Nov 79

We performed a detailed and comprehensive study of the involvement of tumor suppressor genes in human prostate cancer. We utilized primers flanking either the restriction fragment length polymorphism (RFLP) or variable number of tandem repeat [VNTR; microsatellite or simple repeat site (SRS)] polymorphic sites to polymerase chain reaction (PCR) amplify the genomic DNA and detect loss of heterozygosity of the target genes. Quantitative reverse transcription (RT)-PCR was performed to measure the mRNA expression levels and PCR/single strand conformational polymorphism (SSCP) and DNA sequencing carried out to detect mutation of the tumor suppressor genes. We found that multiple tumor suppressor genes (e.g., p53, DCC, APC, MCC, BRCA1, and WAF1/CIP1) were inactivated at different frequencies via various mechanisms [e.g., loss of heterozygosity (LOH), loss of expression (LOE), mutation, and inactivation by cellular binding protein]. Several important and novel findings are as following: LOH and LOE of the DCC gene, LOH, LOE, and possible mutation of the APC/MCC genes, LOH of the BRCA1 locus, and mutation of the WAF1/CIP1 gene. For p53 tumor suppressor gene alone, multiple inactivation mechanisms (i.e., LOH, LOE, mutation, and amplification of the cellular inactivating protein MDM2) were identified. A possible involvement of genomic instability or mutator phenotype in human prostate cancer was investigated by microsatellite typing using PCR. A high frequency of microsatellite instability was detected and the microsatellite instability found to correlate with advanced stage and poor differentiation of prostate cancer, suggesting that genes functioning in DNA mismatch repair or general stabilization of the genome may be involved in prostate cancer. The results obtained in this study suggested that multiple tumor suppressor genes (both known and unknown genes) may share the role in prostate cancer; a pattern which has been found in a number of human malignancies such as cancers of the esophagus, colon and breast. In fact, we performed deletion studies aimed at localizing potential tumor suppressor loci on various chromosomal regions. A number of chromosomal regions (i.e., 6p12-24 and 17q21) were found to potentially harbor unidentified tumor suppressor genes. Detailed deletion mapping has localized the potential tumor suppressor loci to a < 2 Mb region centromeric to the BRCA1 gene on chromosome 17q. In addition, we identified a number of novel mechanisms of tumor suppressor gene inactivation, in prostate cancer such as loss of mRNA expression of the DCC, APC, MCC and p53 gene, and mutator phenotype. And for the very first time, we identified somatic mutations of the WAF1/CIP1 gene in primary human malignancy-human prostate cancer. This finding provides the first evidence in primary tumor that the WAF1/CIP1 gene may be a tumor suppressor gene and may be involved in prostate cancer. We identified 12-lipoxygenase (12-LOX) as a potential prognostic marker for human prostate cancer. mRNA expression levels of the 12-LOX gene was measured by quantitative reverse transcription-polymerase chain reaction (RT-PCR) and semi-quantitative in situ hybridization (ISH) in 122 pairs of matched normal and tumor tissues from prostate cancer patients. We found that 12-LOX expression levels were elevated in approximately half of the patients analyzed and the 12-LOX elevation correlates with advanced stage, poor differentiation, and surgical margin positivity. Our data suggest that 12-LOX may serve as a correlative marker for a more aggressive phenotype of prostate cancer and therefore for poor prognosis. We are currently refining our assays for possible clinical applicability. Since not all patients with loss of expression of the DCC gene showed LOH of the DCC locus, there must be other mechanism(s) responsible for loss of expression of the DCC gene. When we analyzed the relationship between DCC loss of expression and 12-LOX elevation in prostate cancer pati
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PMID:Involvement of the multiple tumor suppressor genes and 12-lipoxygenase in human prostate cancer. Therapeutic implications. 932 30

Loss of heterozygosity (LOH) on 18q predicts poor survival in head and neck squamous cell carcinomas (HNSCCs). Several putative tumor suppressor genes, such as DCC, DPC4/Smad4, and MADR2/Smad2, are mapped to 18q, but thus far, the important gene locus in HNSCC is not known. To identify possible gene loci on 18q, we performed LOH studies using tumor DNA from 57 HNSCC primary tumor cell lines and DNA isolated from fibroblasts or lymphoblastoid cells from the same patients. Forty-two highly polymorphic microsatellite markers spaced not more than 5 cM apart (mean distance, 1.82 cM) spanning the region from D18S44 in 18q11.1 to D18S1141 in 18q23 were used. D18S71 in 18p11.21 on 18p was also used to determine whether the short arm was retained. Forty-three of 57 (75%) HNSCC lines showed LOH or isolated allelic imbalance (AI) for at least one locus on 18q. Although many of the cell lines had large distal 18q deletions with a breakpoint between 18q11.1 and 18q12.2 to qter, three loci were identified that were lost in 70% or more of the cases. The minimally lost regions (MLRs) range in size from 1.5-15.79 cM. The most proximal is centered on D18S39 (1.56 cM) in band 18q21.1, with LOH or isolated AI in 28 of 38 (74%) of informative cases. The largest (15.8 cM) begins at D18S61 (28 of 40; 70%) in band 18q22.2 and extends through D18S50 in 18q23. The third is centered on D18S70 (30 of 40; 75%) in band 18q23 (3.67 cM). Of these MLRs, only the one centered on D18S39 has been implicated previously in HNSCC. D18S70, the most frequently lost marker, was the only marker consistently lost in three tumor cell lines with very minimal losses, UM-SCC-19, UM-SCC-67, and UM-SCC-73A. In addition, UM-SCC-91 exhibited AI only at this locus, and UT-SCC-4 had AI at D18S70 and D18S39 only. Close physical mapping of these three regions may pinpoint one or more previously unidentified tumor suppressor genes.
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PMID:Identification of new minimally lost regions on 18q in head and neck squamous cell carcinoma. 1091 46

Intrahepatic cholangiocarcinoma (ICC) is the second most common malignant primary tumor of the liver in Japan. Despite progress in operative techniques and adjuvant therapy, the prognosis of ICC remains very poor. Therefore, it is important to investigate the mechanism of carcinogenesis and progression of ICC. We screened allelic losses at 6 loci, including that of novel tumor-suppressor gene FEZ1 on chromosome 8p, and at 5 microsatellite loci to define the association with tumor-suppressor genes (HNPCC, APC, RB1, p53, DCC) in tumors from 18 unrelated ICC patients by PCR-loss of heterozygosity (LOH) assay and correlated the alterations with clinicopathological parameters. As a result, 61.1% (11 of 18) of patients showed LOH at 1 of the loci at least, and microsatellite instability was observed in 16.7% (3 of 18). At locus D8S258, relatively frequent LOH was detected (17.6%) compared with other loci on chromosome 8p. Among the other 5 chromosomal arms tested, the highest frequency of LOH (23.5%) was observed at D17S153. Fifty percent of cases with the mass-forming + periductal infiltrating type were frequently detected by LOH at D8S258 compared to cases of the mass-forming or intraductal growth type. In conclusion, we show that 1 putative tumor-suppressor gene on 8p22 may relate to progression of ICC and suggest that the p53 tumor-suppressor gene may be associated with carcinogenesis of ICC.
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PMID:Allelic loss in human intrahepatic cholangiocarcinoma: correlation between chromosome 8p22 and tumor progression. 1100 73

p27 is a cyclin-dependent kinase inhibitor which regulates progression of cells from G1 into S phase in a cell cycle. Loss of the negative regulator may contribute to oncogenesis and tumor progression. The aim of this study was to examine p27 expression in normal mucosa, primary and metastatic tumors from patients with colorectal adenocarcinomas and to analyze association of p27 with patient survival and clinicopathological variables. p27 expression was estimated by immunohistochemistry in 178 primary colorectal cancers, 34 lymph node metastases and 48 normal mucosa samples from patients with colorectal adenocarcinoma. Associations of p27 with patient survival, clinicopathological characteristics and expression of p53, p73 and DCC were analyzed. Loss of p27 was found in 51% of primary tumors, 68% of metastases and 56% of normal samples. The intensity of p27 staining was similar in the matched primary tumor, metastasis and normal mucosa. In patients with Dukes' B or with proximal tumors, the loss of p27 predicted poorer prognosis (p = 0.03 and p = 0.05, respectively). However, there were no significant differences in the patients with other individual Dukes' stage or distal tumors. No relationships were found between p27 and patients' gender, age, tumor location, growth pattern and expression of p53, p73 and DCC (p > 0.05). The data suggest that loss of p27 was associated with poor prognosis in patients with Dukes' B tumor or those with proximal tumor. p27 might be a useful marker to identify the more progressive tumors in these groups.
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PMID:Loss of p27 expression predicts poor prognosis in patients with Dukes' B stage or proximal colorectal cancer. 1140 21

Colorectal carcinogenesis is widely accepted as one of the best-characterized examples of stepwise progression. The existing colorectal carcinogenesis model assumes genetic homogeneity of individual tumors for the main known genetic alterations: K-ras and p53 genes point mutations and loss of heterozygosity (LOH) of chromosome 5q and 18q. The object of the present study was to demonstrate the existence of an intratumor genetic heterogeneity in advanced sporadic colorectal carcinoma for these genetic alterations. Using improved tissue microdissection and DNA extraction, for each tumor, amplifiable DNA was obtained from 15 to 20 areas, of which 1 to 2 concerned lymph node metastases (LNM). This study revealed that 10 of 15 (67%) analyzed tumors were heterogeneous for at least 1 genetic alteration, with between 2 and 6 genotypically different clones detected per tumor. No correlation was observed between the genotype of these subclones and histological differentiation or invasive propensity. Intratumor heterogeneity was more frequently observed for LOH than for point mutations, 67% and 58% for LOH at APC and DCC locus, and 20% for mutation of either the K-ras or p53 gene. In 5 of the 9 (56%) heterogeneous cases with available LNM, the genotype observed in the LNM was different from that of the main clone in the primary tumor, and moreover, 2 of the LNM displayed a genotype undetected in the primary tumor. In conclusion, intratumor genetic heterogeneity was demonstrated in advanced sporadic colorectal carcinoma and was represented as topographically distinct genotypic subclones. Taking into account such a significant genetic heterogeneity of colorectal tumors, the use of genetic markers for prognosis management should be reconsidered.
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PMID:Intratumor genetic heterogeneity in advanced human colorectal adenocarcinoma. 1143 98

Recent studies have led a different view about membrane receptors. While a receptor used to be considered as inactive until bound by its ligand, it has been proposed that some receptors may also be active in the absence of their ligand. These so-called dependence receptors induce a specific death signal when the ligand is absent from the cell. Therefore, the expression of one of these receptors drives the cell to become dependent on the presence of the ligand for its survival. We have hypothesized that this mechanism allows inhibition of tumor growth, by inducing apoptosis of "abnormal" cells that would usually grow when ligand are unavailable--i.e., during local growth of tumor cells or growth beyond primary tumor site -. Along this line, back in the early 90s, Vogelstein and colleagues suggested that a gene called DCC (for "deleted in colorectal cancer") could be a tumor suppressor gene because it was found to be deleted in more than 70 % of colorectal cancers, as well as in many other cancers. During the last fifteen years, controversial data have failed to firmly establish whether DCC is indeed a tumor suppressor gene. However, our observation that DCC behaves as a dependence receptor that induces cell death unless its ligand netrin-1 is present, together with the fact that mice engineered to block DCC-induced cell death by overexpressing netrin-1 are predisposed to develop colorectal tumors, strengthen the role of dependence receptors as tumor suppressors. In this review, we will describe the implication of the netrin-1/receptor pairs as novel negative regulators of tumor development.
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PMID:[Dependence receptors DCC and UNC5H: the role of apoptosis in the control of tumorigenesis]. 1647 Dec 61


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