973 resultados para Small-cell carcinoma


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Several studies indicate that interleukin-6 (IL-6) production is elevated in renal cell carcinoma (RCC) cells, and that IL-6 can serve as an autocrine growth factor in this malignancy. Wild type (wt) p53 represses transcription from the IL-6 promoter in an inducible system. The objective of this study was to determine the role of p53 in regulating constitutive IL-6 production in RCC cells. RCC cell lines containing mutant (mut) p53 produced significantly higher levels of IL-6 than those containing wt p53 (p < 0.05). Transfection of wt p53 into RCC cell lines resulted in significant repression of IL-6 promoter CAT activity p < 0.05). Mutant p53 was less effective at repressing IL-6 promoter activity in ACHN cells, and actually enhanced IL-6 promoter activity in the A498 cell line. A498 cells stably transfected with mutant p53 produced significantly higher levels of IL-6 than A498 cells transfected with an empty expression vector (p < 0.05). Electrophoretic mobility shift assay showed a significant decrease in binding of C/EBP, CREB, and NF-kB transcription factors to the IL-6 promoter in A498 cells transfected with wt p53. Mut p53 was unable to inhibit transcription factor binding to the IL-6 promoter in these cells. Mutant p53-expressing UOK 121LN cells showed decreased binding of C/EBP and CREB, but not NF-kB, following wt p53 transfection. These data suggest that (i) mutation of p53 contributes to the over-expression of IL-6 in RCC; and (ii) wt p53 represses IL-6 expression at least in part by interfering with the binding of C/EBP, CREB, and in some cases, NF-kB transcription factors to the IL-6 promoter. ^

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To discover genes involved in von Hippel-Lindau (VHL)-mediated carcinogenesis, we used renal cell carcinoma cell lines stably transfected with wild-type VHL-expressing transgenes. Large-scale RNA differential display technology applied to these cell lines identified several differentially expressed genes, including an alpha carbonic anhydrase gene, termed CA12. The deduced protein sequence was classified as a one-pass transmembrane CA possessing an apparently intact catalytic domain in the extracellular CA module. Reintroduced wild-type VHL strongly inhibited the overexpression of the CA12 gene in the parental renal cell carcinoma cell lines. Similar results were obtained with CA9, encoding another transmembrane CA with an intact catalytic domain. Although both domains of the VHL protein contribute to regulation of CA12 expression, the elongin binding domain alone could effectively regulate CA9 expression. We mapped CA12 and CA9 loci to chromosome bands 15q22 and 17q21.2 respectively, regions prone to amplification in some human cancers. Additional experiments are needed to define the role of CA IX and CA XII enzymes in the regulation of pH in the extracellular microenvironment and its potential impact on cancer cell growth.

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We and others recently isolated a human p53 homologue (p40/p51/p63/p73L) and localized the gene to the distal long arm of chromosome 3. Here we sought to examine the role of p40/p73L, two variants lacking the N-terminal transactivation domain, in cancer. Fluorescent in situ hybridization (FISH) analysis revealed frequent amplification of this gene locus in primary squamous cell carcinoma of the lung and head and neck cancer cell lines. (We named this locus AIS for amplified in squamous cell carcinoma.) Furthermore, amplification of the AIS locus was accompanied by RNA and protein overexpression of a variant p68AIS lacking the terminal transactivation domain. Protein overexpression in primary lung tumors was limited to squamous cell carcinoma and tumors known to harbor a high frequency of p53 mutations. Overexpression of p40AIS in Rat 1a cells led to an increase in soft agar growth and tumor size in mice. Our results support the idea that AIS plays an oncogenic role in human cancer.

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Antagonists of growth hormone-releasing hormone (GHRH) inhibit the proliferation of various human cancers in vitro and in vivo by mechanisms that include apparent direct effects through specific binding sites expressed on tumors and that differ from pituitary human GHRH (hGHRH) receptors. In this study, GHRH antagonist JV-1–38 (20 μg/day per animal s.c.) inhibited the growth of orthotopic CAKI-1 human renal cell carcinoma (RCC) by 83% and inhibited the development of metastases to lung and lymph nodes. Using ligand competition assays with 125I-labeled GHRH antagonist JV-1–42, we demonstrated the presence of specific high-affinity (Kd = 0.25 ± 0.03 nM) binding sites for GHRH with a maximal binding capacity (Bmax) of 70.2 ± 4.1 fmol/mg of membrane protein in CAKI-1 tumors. These receptors bind GHRH antagonists preferentially and display a lower affinity for hGHRH. The binding of 125I-JV-1–42 is not inhibited by vasoactive intestinal peptide (VIP)-related peptides sharing structural homology with hGHRH. The receptors for GHRH antagonists on CAKI-1 tumors are distinct from binding sites detected with 125I-VIP (Kd = 0.89 ± 0.14 nM; Bmax = 183.5 ± 2.6 fmol/mg of protein) and also have different characteristics from GHRH receptors on rat pituitary as documented by the insignificant binding of [His1,125I-Tyr10,Nle27]hGHRH(1–32)NH2. Reverse transcription-PCR revealed the expression of splice variants of hGHRH receptor in CAKI-1 RCC. Biodistribution studies demonstrate an in vivo uptake of 125I-JV-1–42 by the RCC tumor tissue. The presence of specific receptor proteins that bind GHRH antagonists in CAKI-1 RCC supports the view that distinct binding sites that mediate the inhibitory effect of GHRH antagonists are present on various human cancers.

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Objective: To determine how patients with lung cancer value the trade off between the survival benefit of chemotherapy and its toxicities.

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Semaphorins and collapsins make up a family of conserved genes that encode nerve growth cone guidance signals. We have identified two additional members of the human semaphorin family [human semaphorin A(V) and human semaphorin IV] in chromosome region 3p21.3, where several small cell lung cancer (SCLC) cell lines exhibit homozygous deletions indicative of a tumor suppressor gene. Human semaphorin A(V) has 86% amino acid homology with murine semaphorin A, whereas semaphorin IV is most closely related to murine semaphorin E, with 50% homology. These semaphorin genes are approximately 70 kb apart flanking two GTP-binding protein genes, GNAI-2 and GNAT-1. In contrast, other human semaphorin gene sequences (human semaphorin III and homologues of murine semaphorins B and C) are not located on chromosome 3. Human semaphorin A(V) is translated in vitro into a 90-kDa protein, which accumulates at the endoplasmic reticulum. The human semaphorin A(V) (3.4-kb mRNA) and IV (3.9- and 2.9-kb mRNAs) genes are expressed abundantly but differentially in a variety of human neural and nonneural tissues. Human semaphorin A(V) was expressed in only 1 out of 23 SCLCs and 7 out of 16 non-SCLCs, whereas semaphorin IV was expressed in 19 out of 23 SCLCs and 13 out of 16 non-SCLCs. Mutational analysis in semaphorin A(V) revealed mutations (germ line in one case) in 3 of 40 lung cancers. Our data suggest the need to determine the function of human semaphorins A(V) and IV in nonneural tissues and their role in the pathogenesis of lung cancer.

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The squamous cell carcinoma antigen (SCCA) is a member of the ovalbumin family of serine proteinase inhibitors (serpins). A neutral form of the protein is found in normal and some malignant squamous cells, whereas an acidic form is detected exclusively in tumor cells and in the circulation of patients with squamous cell tumors. In this report, we describe the cloning of the SCCA gene from normal genomic DNA. Surprisingly, two genes were found. They were tandemly arrayed and flanked by two other closely related serpins, plasminogen activator inhibitor type 2 (PAI2) and maspin at 18q21.3. The genomic structure of the two genes, SCCA1 and SCCA2, was highly conserved. The predicted amino acid sequences were 92% identical and suggested that the neutral form of the protein was encoded by SCCA1 and the acidic form was encoded by SCCA2. Further characterization of the region should determine whether the differential expression of the SCCA genes plays a causal role in development of more aggressive squamous cell carcinomas.

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Background e scopi dello studio. Il carcinoma renale rappresenta circa il 3% delle neoplasie e la sua incidenza è in aumento nel mondo. Il principale approccio terapeutico alla malattia in stadio precoce è rappresentato dalla chirurgia (nefrectomia parziale o radicale), sebbene circa il 30-40% dei pazienti vada incontro a recidiva di malattia dopo tale trattamento. La probabilità di recidivare può essere stimata per mezzo di alcuni noti modelli prognostici sviluppati integrando sia parametri clinici che anatomo-patologici. Il limite principale all’impiego nella pratica clinica di questi modelli è legata alla loro complessità di calcolo che li rende di difficile fruizione. Inoltre la stratificazione prognostica dei pazienti in questo ambito ha un ruolo rilevante nella pianificazione ed interpretazione dei risultati degli studi di terapia adiuvante dopo il trattamento chirurgico del carcinoma renale in stadio iniziale. Da un' analisi non pre-pianificata condotta nell’ambito di uno studio prospettico e randomizzato multicentrico italiano di recente pubblicazione, è stato sviluppato un nuovo modello predittivo e prognostico (“score”) che utilizza quattro semplici parametri: l’età del paziente, il grading istologico, lo stadio patologico del tumore (pT) e della componente linfonodale (pN). Lo scopo del presente studio era quello di validare esternamente tale score. Pazienti e Metodi. La validazione è stata condotta su due coorti retrospettive italiane (141 e 246 pazienti) e su una prospettica americana (1943 pazienti). Lo score testato prevedeva il confronto tra due gruppi di pazienti, uno a prognosi favorevole (pazienti con almeno due parametri positivi tra i seguenti: età < 60 anni, pT1-T3a, pN0, grading 1-2) e uno a prognosi sfavorevole (pazienti con meno di due fattori positivi). La statistica descrittiva è stata utilizzata per mostrare la distribuzione dei diversi parametri. Le analisi di sopravvivenza [recurrence free survival (RFS) e overall survival (OS)] sono state eseguite il metodo di Kaplan-Meier e le comparazioni tra i vari gruppi di pazienti sono state condotte utilizzando il Mantel-Haenszel log-rank test e il modello di regressione di Cox. Il metodo di Greenwood è stato utilizzato per stimare la varianza e la costruzione degli intervalli di confidenza al 95% (95% CI), la “C-statistic” è stata utilizzata per descrivere l’ accuratezza dello score. Risultati. I risultati della validazione dello score condotta sulle due casistiche retrospettive italiane, seppur non mostrando una differenza statisticamente significativa tra i due gruppi di pazienti (gruppo favorevole versus sfavorevole), sono stati ritenuti incoraggianti e meritevoli di ulteriore validazione sulla casistica prospettica americana. Lo score ha dimostrato di performare bene sia nel determinare la prognosi in termini di RFS [hazard ratio (HR) 1.85, 95% CI 1.57-2.17, p < 0.001] che di OS [HR 2.58, 95% CI 1.98-3.35, p < 0.001]. Inoltre in questa casistica lo score ha realizzato risultati sovrapponibili a quelli dello University of California Los Angeles Integrated Staging System. Conclusioni. Questo nuovo e semplice score ha dimostrato la sua validità in altre casistiche, sia retrospettive che prospettiche, in termini di impatto prognostico su RFS e OS. Ulteriori validazioni su casistiche internazionali sono in corso per confermare i risultati qui presentati e per testare l’eventuale ruolo predittivo di questo nuovo score.

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Thesis (Ph.D.)--University of Washington, 2016-06

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Purpose: The effectiveness of synchronous carboplatin, etoposide, and radiation therapy was prospectively assessed in a group of patients with high-risk Merkel cell carcinoma (MCC) of the skin. Patients and Methods: Patients were eligible if they had disease localized to the primary site and nodes, and were required to have at least one of the following high risk features: recurrence after initial therapy, involved nodes, primary tumor size greater than 1 cm, gross residual disease after surgery, or occult primary with nodes. Radiation was delivered to the primary site and nodes to a dose of 50 Gy in 25 fractions over 5 weeks and synchronous carboplatin (area under the curve, 4.5) and intravenous etoposide 80 mg/m(2) days 1 to 3 was given in weeks 1, 4, 7, and 10. The median age of the group was 67 (range, 43-86) years, and there were 39 males and 14 females. Involved nodes (stage II) were present in 33 cases (62%). The sites involved were head and neck (22 patients), occult primary (13 patients), upper limb (eight patients), lower limb (eight patients), and trunk (two patients). Results: Fifty-three patients were entered between 1996 and 2001. The median potential follow-up was 48 months. There were no treatment related deaths. The 3-year overall survival, locoregional control, and distant control were 76%, 75%, and 76%, respectively. Tumor site and the presence of nodes were factors that were predictive for local control and survival. Multivariate analysis indicated that the major factor influencing survival was the presence of nodes; however, this was not a significant factor in locoregional control. Conclusion: High levels of locoregional control and survival have been achieved with the addition of chemotherapy to radiation treatment for high-risk MCC of the skin. The role of chemoradiotherapy for high-risk MCC warrants further investigation. (C) 2003 by American Society of Clinical Oncology.