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

Bacillus Calmette-Guerin (BCG) has been shown in randomized trials to be the most effective agent against superficial bladder tumors. BCG therapy prevents or reduces tumor recurrences, abrogates tumor progression and improves survival over surgery alone. The optimal BCG schedule varies among patients, reflecting a heterogeneous tumor population. Multifocality, high grade (G2,3) and T1 tumors are risk factors for tumor recurrence or invasion. Patients presenting with such features are most likely to benefit from BCG. An incomplete response to BCG portends a high risk of tumor progression. Non-responders have a 40-60% risk of developing muscle invasion or metastases within 10 years, compared with 10-15% for BCG responders. Further, 80% of non-responders progress in the bladder within 3-5 years. After 5 years, relapses are more common in the prostate (13-35%) and upper collecting system (15-33%); one-half of these are invasive tumors. This suggests that intense therapy directed at premalignant and early bladder lesions coupled with a chemoprevention strategy designed to protect the whole urothelium will be required to reverse a pan-urothelial tumor diathesis.
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PMID:Intravesical BCG: current results, natural history and implications for urothelial cancer prevention. 130 73

Approximately 70% of all bladder cancers are superficial at the time of presentation. Superficial bladder cancer includes tumors confined to the urothelium (clinical stage Ta) or lamina propria (stage T1) and flat carcinoma in situ (stage Tis). Because the biological behavior of bladder neoplasms is variable, several important prognostic factors must be addressed. Multivariate analyses have shown that factors predictive of tumor recurrence and tumor progression include multifocal tumors, high grade tumors, T1 tumors and positive urinary cytology after transurethral resection (TUR). The patient with superficial bladder cancer should be monitored via endoscopy supplemented by urinary cytology, using either voided or bladder irrigation specimens and urinalysis. Frequent intravenous urography is not required, even in high grade tumors, as long as the clinical and pathologic studies remain negative and the patient is asymptomatic. The "gold standard" of treatment for superficial bladder carcinoma is TUR of the entire tumor. Despite TUR, new tumors will occur in approximately 50% of all patients; those at highest risk for tumor recurrence and progression require adjuvant intravesical therapy after TUR. A variety of drugs are used as intravesical therapy, including thiotepa, mitomycin C, doxorubicin hydrochloride, Bacillus Calmette-Guerin (BCG), epirubicin, and interferon. Although associated with the most toxicity, BCG appears to be the most efficacious agent in increasing the time to recurrence and progression and in reducing the recurrence rate.
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PMID:Superficial bladder cancer: diagnosis, surveillance and treatment. 130 74

We are now beginning to understand the development of bladder cancer at the molecular level. Tumor evolution involves the interaction of both oncogenes and tumor suppressor genes. One of the key tumor suppressor genes in this process is the retinoblastoma (RB) gene. Much has been learned recently about the role of this gene in the tumor progression and prognosis of bladder cancer, although several questions are still unanswered. The progress made on this subject in our laboratory as well as others will be the focus of this report.
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PMID:Altered RB expression is a prognostic clinical marker involved in human bladder tumorigenesis. 130 91

Histological and anatomopathological studies performed on 152 independent myeloblastosis-associated virus type 1 (MAV1)-induced nephroblastomas allowed us to precisely define the chronology of tumor development in chickens. Three tumors representing increasing developmental stages were used to construct genomic libraries and to study both the state of proviral genomes and the sites of MAV1 integration in genomic DNA. We established that increasing levels of proviral rearrangement, eventually leading to the elimination of infectious MAV genomes, were associated with tumor progression and that 22 individual tumors, representative of different developmental stages, did not contain any common MAV1 integration site. Cloning of cellular fragments flanking the MAV1-related proviruses in tumor DNA showed that each one of eight nephroblastomas tested expressed a high level of an as yet unidentified cellular gene (nov) whose transcription is normally arrested in adult kidney cells. Cloning of the normal nov gene established that in one tumor, fused long terminal repeat-truncated nov mRNA species were expressed, indicating that at least in that case, the high level of nov expression was under the control of the MAV long terminal repeat promoter. The normal nov gene encodes a putative 32-kDa secreted polypeptide, which is a member of a new family of proteins likely to be involved in cell growth regulation. We also showed that the expression of an amino-terminal-truncated nov product in chicken embryo fibroblasts was sufficient to induce their transformation.
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PMID:Proviral rearrangements and overexpression of a new cellular gene (nov) in myeloblastosis-associated virus type 1-induced nephroblastomas. 130 86

Although oncogenes and tumor suppressor genes have been implicated in carcinogenesis and tumor progression, their relationship to the development of genomic instability has not been elucidated. To examine this role, we transfected oncogenes (polyomavirus middle [Py] and large T [MT and LT]) and adenovirus serotype 5 E1A) into two NIH 3T3-derived cell lines, EN/NIH 2-4 and EN/NIH 2-20. Both cell lines contain two stable integrants of a variant of the retrovirus vector pZipNeoSV(x)1 that has been modified by deletion of the enhancer elements from the long terminal repeats. DNA rearrangements activating the silent neomycin phosphotransferase gene (neo) present in these integrants were identified by selection of cells in the antibiotic G418. Whereas control-transfected EN/NIH cell lines do not yield G418-resistant subclones (GRSs), a fraction of oncogene-transfected EN/NIH 2-4 (8 of 19 Py MT, 5 of 17 Py LT, and 11 of 19 E1A) and 2-20 (7 of 15 Py MT) cell lines gave rise to GRSs at differing frequencies (0.33 x 10(-6) to 46 x 10(-6) for line 2-4 versus 0.11 x 10(-6) to 1.3 x 10(-6) for line 2-20) independent of cell generation time. In contrast, a distinctly smaller fraction of mutant Py MT-transfected EN/NIH cell lines (1 of 10 MT23, 1 of 10 MT1015, and 0 of 10 MT59b) resulted in GRSs. Southern analysis of DNA from selected oncogene-transfected GRSs demonstrated genomic rearrangements of neo-containing cellular DNA that varied in type (amplification and/or novel fragments) and frequency depending on the specific oncogene and EN/NIH cell line used in transfection. Furthermore, only one of the two neo-containing genomic loci present in both EN/NIH cell lines appeared to be involved in these genomic events. In addition to effects related to the genomic locus, these observations support a role for oncogenes in the development of genetic changes associated with tumor progression.
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PMID:Oncogenes result in genomic alterations that activate a transcriptionally silent, dominantly selectable reporter gene (neo). 130 88

We have analysed the splicing patterns of human papillomavirus (HPV) type-16 mRNAs in a human epithelial cell line immortalized by HPV 16 (HPKII), in cell lines established from cervical carcinomas (SiHa and CaSki) and in pre-invasive and invasive carcinomas of the cervix. The presence of mRNA species previously described, which could encode the E6, E6I, E6II, E6III, E7, E2, E2C, E4, E5 and L1 proteins, was determined, using the RNA polymerase chain reaction (PCR) technique with primers that flank unique splice sites. The state of the viral DNA in the tumor biopsies was established by Southern blot analysis. The various HPV 16 transcripts could be detected in cell lines and in tumor biopsies. The size of the RNA PCR products were in agreement with the previously mapped splice sites. The full range of transcripts was revealed in the HPKII cell line and in a number of pre-invasive carcinomas. Messenger RNAs which could encode the E6III, E4 and E5 proteins were most prevalent in all types of tumor. The overall results of DNA and RNA analyses in cell lines and tumor specimens indicate that (1) expression of either of the early or late transcripts studied is not specifically related to (a) tumor stage or (b) the physical state of the viral genome; and (2) alterations in the splicing patterns of HPV 16 transcripts may not be involved in tumor progression.
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PMID:Expression and splicing patterns of human papillomavirus type-16 mRNAs in pre-cancerous lesions and carcinomas of the cervix, in human keratinocytes immortalized by HPV 16, and in cell lines established from cervical cancers. 131 Apr 88

Malignant astrocytomas often display histopathological heterogeneity. In the present study, we have molecularly characterized different areas within 4 such tumors to determine whether the tissue heterogeneity can be explained by differences in DNA constitution. Two tumors contained low grade areas, and the other 2 had areas with satellitosis. The tumors were examined for loss of heterozygosity with markers from chromosomes 9p, 10, and 17p and for amplification of the epidermal growth factor receptor gene. In each case, the high grade portion of the tumor displayed at least one of these structural alterations. However, identical alterations were found in the associated low grade or satellitosis areas of each tumor. Our data suggest that: (a) genetic alterations associated with tumor progression already occur in histopathologically low grade areas of high grade astrocytoma; (b) satellitosis associated with a high grade astrocytoma has to be considered as part of that tumor; and (c) tissue heterogeneity within a high grade astrocytoma is not a consequence of differences in DNA constitution at the loci that were examined.
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PMID:Molecular characterization of areas with low grade tumor or satellitosis in human malignant astrocytomas. 131 34

The mutagenic potentials of the human bladder carcinogen 4-amino-biphenyl (ABP) and three of its proximate carcinogenic metabolites, N-hydroxy-4-aminobiphenyl (N-OH-ABP), N-hydroxy-4-acetylaminobiphenyl (N-OH-AABP) and N-acetoxy-4-acetylaminobiphenyl (N-OAc-AABP) were tested on a prime human target cell type for carcinogenesis, human uroepithelial cells (HUC). SV-HUC (PC), a near diploid, clonally derived, nontumorigenic SV40-immortalized human uroepithelial cell line that is transformable to tumorigenicity after exposure to ABP and its metabolites, was used for quantitative mutation assays. The end point used was the induction of mutations in the hypoxanthine-guanine phosphoribosyltransferase (HGPRT) locus, selected using 6-thioguanine resistance (TGr). A single, 24-h exposure of SV-HUC to ABP, N-OH-ABP, N-OH-AABP, or N-OAc-AABP caused a statistically significant, dose-dependent increase in mutation frequency resulting in a 2-30-fold increase in the number of TGr mutants in carcinogen-exposed groups compared to untreated controls. These chemicals were similarly mutagenic towards MC-T11, an SV-HUC-derived low grade tumor cell line that was also shown to be responsive to transformation (in a separate study) by ABP, N-OH-ABP, or N-OH-AABP as judged by the generation of higher grade tumors. In contrast, the mutagenic potencies of ABP and N-OH-ABP were lower when tested on a subclone of SV-HUC (BC) that is refractory to transformation by these chemicals. Thus, these data support a model of transformation in which ABP as well as its metabolites contribute to tumorigenic transformation and neoplastic progression of HUC by inducing mutations in susceptible target cell genes.
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PMID:Induction of thioguanine-resistant mutations in human uroepithelial cells by 4-aminobiphenyl and its N-hydroxy derivatives. 131 36

Thirty-five adult recurrent GBM patients, divided randomly in two groups of 19 and 16 cases, had been treated with two regimens of chemotherapy: a) 'eight-drugs-in-one-day'; b) procarbazine + CCNU + vincristine (PCV) respectively. Chemotherapy was planned at the tumour relapse and delivered as long as tolerated without irreversible sequelae or until the CT scan showed tumor progression. Multiple agents are used simultaneously in the therapeutic approach using 'eight-in-one' to kill as many heterogeneous cells of malignant glial tumor as possible and minimize the emergence of cellular resistance to chemotherapy. Rate response to chemotherapy and the median adjunctive survival time (6.5 and 6 months, respectively) are not significantly different in the two arms of this study. Our experience with such an aggressive multi-drugs combination 'eight-in-one-day' was disappointing if compared with less toxic, better tolerated and easy delivered (PCV) regimen.
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PMID:Efficacy of '8-drugs-in-one-day' combination in treatment of recurrent GBM patients. 131 60

A 19-year-old woman presented with a large mediastinal mass, histologically shown to be malignant lymphoma of lymphoblastic type (LBL). Immunophenotypic and gene rearrangement analysis unequivocally demonstrated that the neoplasm was of B-cell lineage. The neoplastic cells expressed terminal deoxynucleotidyl transferase, the pan-B cell antigens CD19, CD20, and CD22, and were negative for immunoglobulins and numerous T-cell antigens tested. Southern blot analysis showed rearrangement of one allele of the immunoglobulin heavy chain gene while the immunoglobulin kappa and T-cell receptor beta chain genes were in the germline configuration. Thus, the immunophenotypic and molecular findings in this case correspond to an early stage of B-cell differentiation, the pre-pre B-cell stage as has been named by others. In contrast with LBL of immature T-cell lineage, precursor B-cell LBLs involving the mediastinum are truly rare. Occasional cases have been reported that have arisen elsewhere and subsequently involved the mediastinum at time of relapse or tumor progression. Well-documented examples of immature B-cell LBL arising in the mediastinum are virtually unreported. The site and cell population giving rise to this neoplasm is unknown. However, origin from precursors of normal thymic medullary B cells is proposed as one possibility.
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PMID:Mediastinal lymphoblastic lymphoma with an immature B-cell immunophenotype. 131 99


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