Search PubMed⌕ Search

Biomedical subjects

W M Linehan

Publications and source records attributed to W M Linehan.

At least 163 records · Page 9Linked to original sources
PubMed1994

Suramin inhibits proliferation and DNA synthesis in transitional carcinoma cell lines.

Suramin is polysulfonated naphthylurea which has a broad range of antitumor activity. The mechanism of action of suramin is not completely understood, although it is known to inhibit enzymes in all cellular compartments, inhibit steroidogenesis and interfere with ligand-receptor binding. Suramin's large molecular size and negative charge should make it poorly absorbed through the bladder mucosa, a desired characteristic for an intravesical chemotherapeutic agent. We examined the ability of suramin to inhibit thymidine uptake and decrease cellular proliferation in 4 transitional cell carcinoma cell lines grown in vitro to determine if suramin might be a new candidate drug of treatment for patients with superficial bladder cancer. Suramin inhibited cellular proliferation of all cell lines tested (MBT2, T24, RT4 and TCCSUP) in a dose-dependent fashion. Fifty per cent inhibition of cellular proliferation compared with controls was seen with suramin concentrations of 250 to 400 micrograms/ml. by, at most, 5 to 9 days of exposure. The cell line RT4 was the cell line most sensitive to the growth inhibitory effect of suramin, with 50% growth inhibition compared with controls achieved after 3 days' exposure to a suramin concentration of 100 micrograms/ml. Suramin inhibited DNA synthesis in a dose-dependent fashion, as measured by thymidine uptake, in 3 of the 4 cell lines tested (MBT2, T24, and RT4). Suramin inhibited thymidine uptake by TCCSUP in a dose-dependent fashion, but did not achieve statistical significance.

Animals↗
PubMed1994

Hereditary papillary renal cell carcinoma.

We describe a 3 generation family with members affected with papillary renal cell carcinoma, an uncommon histological type of renal cell carcinoma. Multiple tumors of varying size were present in both kidneys of affected family members. The disorder was not linked to polymorphic markers on chromosome 3p and there was no loss of heterozygosity at loci on 3p in renal tumors. The results suggest the presence of a renal cell carcinoma gene not located on 3p that predisposes to renal cell carcinoma with a distinct histological appearance. The inherited disorder in this family appears to be different from recognized hereditary cancer syndromes.

Adolescent↗
PubMed1994

cDNA cloning and expression of the human homolog of the sea urchin fascin and Drosophila singed genes which encodes an actin-bundling protein.

cDNA clones having extensive sequence identity with the sea urchin fascin and the Drosophila singed gene products were isolated from a human teratocarcinoma cDNA library. The human homolog, termed hsn, is a single-copy gene that was localized to human chromosome 7p22 by fluorescence in situ hybridization and is predicted to encode a 493-amino-acid product with a molecular mass of approximately 55,000. This protein would be similar in size to the fascin and singed proteins, as well as a previously described 55-kD actin-bundling protein that was purified from HeLa cells. Monoclonal antibodies directed against the 55-kD HeLa protein were reactive against a bacterially expressed hsn fusion protein, indicating that the hsn gene probably encodes the 55-kD protein. The hsn mRNA was variably expressed in all human tissues analyzed and was highly expressed in actively growing renal carcinoma cell lines and in activated, but not in resting, lymphocytes, suggesting a functional role for hsn in proliferation. The fascin family lacks homology with other characterized actin-binding proteins, and the high degree of evolutionary conservation of these proteins indicates a functional importance of their actin-bundling properties.

Amino Acid Sequence↗
PubMed1994

Associations between bladder cancer risk factors and tumor stage and grade at diagnosis.

Using data on 1,860 bladder cancer cases and 3,934 population-based controls from the National Bladder Cancer Study, we examined associations between suspected bladder cancer risk factors and tumor stage and grade. Employment in a high-risk occupation was associated with the entire clinical spectrum of bladder cancer rather than a particular tumor stage or grade. For example, relative risks (RR) were similar for noninvasive and invasive disease (1.5 and 1.6, respectively). Cigarette smoking also increased risk of the entire clinical spectrum of bladder cancer, but the more advanced the stage, the stronger the effect. For example, relative risks of noninvasive and invasive bladder cancer for current heavy smokers were 3.0 and 5.2, respectively. Cigarette smoking was associated with higher risk of low-grade than high-grade tumors, once stage of disease was taken into account. Compared with whites, nonwhites were at a lower risk of noninvasive bladder cancer (RR = 0.4) but at similar risk of invasive bladder cancer (RR = 1.1), a pattern indicating racial differences in health practices related to bladder cancer detection. History of urinary tract infections and bladder stones was associated with increasing relative risks for advanced tumor stage. Heavy artificial sweetener use was associated with higher-grade, poorly differentiated tumors. Coffee consumption and family history of bladder cancer were not consistently associated with tumor stage or grade. Overall, different clinical presentations of bladder cancer share most suspected bladder cancer risk factors, including employment in a high-risk occupation and cigarette smoking.

Adult↗
PubMed1994

Molecular analysis of the von Hippel-Lindau disease tumor suppressor gene in human lung cancer cell lines.

The deletion of the short arm of chromosome 3 is frequently observed in lung cancer. To determine whether the von Hippel-Lindau (VHL) disease tumor suppressor gene located at 3p25 is responsible for oncogenesis in lung cancer, we searched the known open reading frame using the single-strand conformation polymorphism (SSCP) technique for mutations in the VHL gene in 72 cancer cell lines including small cell (SCLC) and non-small cell (NSCLC) lung cancers, carcinoids, and mesotheliomas. SSCP analysis showed that four cell lines have altered SSCP patterns within the coding region and one in an intron of the VHL gene. SCLC line NCI-H1672 had a somatic mutation, G to A at nucleotide (nt) 530, leading to amino acid substitution (glycine to aspartic acid) compared to normal DNA from the same patient. Mesothelioma line NCI-H28 had T to A mutation at nt 479 leading to leucine to histidine amino acid change. We found one frequent polymorphism A (0.72) or G (0.28) at nt 19 resulting in either serine or glycine at this position, changes also found in normal peripheral blood cell DNA, often in a heterozygous state. In addition, we found single rare polymorphisms which did not alter the coding region including: C to G at nt 396, G to T at nt 843, and C to T change in an intron. These results suggest that the VHL gene is only rarely mutated in thoracic malignancies.

Base Sequence↗
PubMed1994

Examination of human tumors for rhoA mutations.

rhoA encodes a ras-related GTP-binding protein that is thought to play a role in cytoskeletal organization. Recent evidence has suggested both that rhoA could act either as a dominant oncogene, since transfection of both normal and activated rho genes confer a transformed phenotype on fibroblast cells in culture, or as a recessive tumor suppressor gene, by virtue, in part, of its chromosomal location at 3p21, a site deleted in many human malignancies. In either case, a role for rhoA in the oncogenesis of human tumors would be supported by the finding of rhoA mutations in tumors. We therefore examined human tumors and cell lines for mutations in the protein coding regions of rhoA by RNAase protection analysis. We first examined the expression of rhoA in renal cell carcinoma cell lines in which 3p21 was heterozygously deleted or retained. We found no evidence for rhoA mutations in these specimens. We also examined RNA from lung, breast, colon or ovarian tumors and also found no evidence of activating rhoA mutations. Furthermore, there was no relation between the level of rhoA mRNA expression and the presence or absence of 3p21 deletions in the renal cell carcinoma specimens. Thus, although rhoA has transforming potential in vitro, there is no evidence that it is activated by mutation in human malignancies, or that it could act as a tumor suppressor gene in tumors in which 3p21 is deleted.

Carcinoma, Renal Cell↗
PubMed1993

Chromosome 17p deletions and p53 mutations in renal cell carcinoma.

Studies of the role of tumor suppressor genes in human renal cell carcinoma from our laboratory have suggested the presence of a disease gene(s) on the short arm of chromosome 3. Little is known about the role other tumor suppressor genes may play in this malignancy. Abnormalities of chromosome 17p and, in particular of p53, are common in many human malignancies. In order to evaluate the role of this region in renal cell carcinoma, we performed restriction fragment length polymorphism analyses of chromosome 17 with probes localized to the p53 region. Fourteen of 29 (48%) evaluable cell lines showed loss of heterozygosity at this locus. Northern blot analysis did not detect a p53 transcript in 4 of 27 cell lines tested. In addition, we screened cell lines for p53 mutations using a polymerase chain reaction-single strand conformation polymorphism technique. Cell lines positive for mutations by this technique were then sequenced. Mutations were detected in 11 of 33 (33%) cell lines, including 8 derived from primary tumors and 3 derived from metastatic foci. Six of 9 (67%) patients with loss of heterozygosity demonstrated a mutation in the remaining allele, while only 1 of 8 (13%) without loss of heterozygosity had a mutation. Three of 3 (100%) cell lines derived from metastases had the same mutation as their matched primary cell line. Loss or mutation of p53 did not correlate either with loss of chromosome 3p or with histological subtype. These results suggest that, while the primary disease gene for kidney cancer appears to be on chromosome 3, abnormalities of p53 are common and may be involved in the progression of this malignancy.

Base Sequence↗
PubMed1993

Prospective randomized trial of high-dose interleukin-2 alone or in conjunction with lymphokine-activated killer cells for the treatment of patients with advanced cancer.

BACKGROUND: Treatment using interleukin-2 (IL-2) alone or in conjunction with lymphokine-activated killer (LAK) cells has been shown to mediate disease regression in selected patients with advanced cancer. PURPOSE: This prospective randomized trial was designed to determine whether the administration of LAK cells in conjunction with high-dose IL-2 alters response and survival rates, compared with those for IL-2 alone, in patients with advanced cancer. METHODS: The 181 patients who had metastatic cancer that had failed to respond to standard therapy or who had disease for which no effective therapy existed received treatment with high-dose IL-2 alone or with LAK cells plus IL-2. Both treatment groups were to receive the same dose of IL-2 administered according to the same schedule. IL-2 doses were omitted depending on the tolerance of the patient. Of the 181 patients, 97 had renal cell cancer and 54 had melanoma. RESULTS: Median potential follow-up was 63.2 months. There were 10 complete responses among the 85 assessable patients who received IL-2 plus LAK cells, compared with four among the 79 who received IL-2 alone. There were 14 and 12 partial responses, respectively. Complete response continues in seven patients at 50-66 months. The 36-month actuarial survival with IL-2 plus LAK cells was 31%, compared with 17% with IL-2 alone (two-sided P value [P2] = .089). A trend toward improved survival was seen for patients with melanoma who received IL-2 plus LAK cells, compared with those who received IL-2 alone (24-month survival: 32% versus 15%; 48-month survival: 18% versus 4%; P2 = .064 [corrected]). None of 26 patients with melanoma who received IL-2 alone are alive; five of 28 who received IL-2 plus LAK cells are alive, and three continue in complete response. No difference in survival was seen in patients with renal cell cancer in the two treatment groups. There were six treatment-related deaths (3.3%); three were due to myocardial infarction. Other toxic effects resolved by discontinuation of IL-2. Many toxic effects were related to increased vascular permeability induced by IL-2. CONCLUSIONS: Some patients with metastatic cancer have prolonged remission when they are treated with high-dose IL-2 alone or in conjunction with LAK cells. Our results suggest a trend toward increased survival when IL-2 is given with LAK cells in patients with melanoma, but no trend was observed for patients with renal cell cancer. IMPLICATIONS: As these studies continue, efforts are underway to develop improved immunotherapies using tumor-infiltrating lymphocytes (TIL) and gene-modified TIL.

Adolescent↗
PubMed1993

Effect of suramin on the mitogenic response of the human prostate carcinoma cell line PC-3.

BACKGROUND: Suramin is an anthelmintic drug that recently has been shown to have clinical efficacy in the treatment of patients with some advanced malignancies, including prostate carcinoma. The current study was done to assess the effect of suramin at clinically relevant doses on the growth in culture of a human prostatic carcinoma cell line, PC-3. METHODS: The antiproliferative effect of varying doses of suramin on PC-3 was assessed. Northern blot analysis was done to assess the potential changes in genetic expression at different times after the initiation of treatment. RESULTS: Suramin inhibited the proliferation of PC-3 in a dose-related manner (concentration range, 30-300 microM). Compared with fetal calf serum 2%, when the cells were grown in fetal calf serum 10%, higher concentrations of suramin were required to inhibit tritiated thymidine incorporation. When grown in RPMI without supplement, the PC-3 cell number remained the same. When 100 microM suramin was included, the cell number decreased. By contrast, when RPMI was supplemented with insulin, transferrin, and selenium (ITS), PC-3 grew well. The inhibition of the proliferation of PC-3 cells by suramin was decreased when ITS were added to the cells grown under serum-free conditions. CONCLUSIONS: These results were consistent with the hypothesis that in vitro inhibition of the growth of PC-3 cells by suramin may be caused, at least in part, by the growth factor antagonism of the drug. In fetal calf serum 2%, the suramin inhibition was reversible after 3 days. If the treatment was extended to 6 days, however, the PC-3 cells were unable to recover. Cell-cycle analysis revealed that, after 6 days of treatment, there was a decrease in the number of cells in G1 that corresponded with an increased number of cells in G2/M. This suggested that critical antineoplastic events were occurring during this time. Molecular analysis did not detect any altered expression of actin, transforming growth factors alpha or beta, or histone compared with untreated control samples.

Blotting, Northern↗
PubMed1993

Flow cytometric DNA analysis of interleukin-2 responsive renal cell carcinoma.

Adoptive immunotherapy using interleukin-2 (IL-2) based therapy can result in marked tumor regression in some patients with metastatic renal cell carcinoma. DNA flow cytometry has not been previously studied as a predictor of outcome of this therapy. Archival paraffin embedded tumors were studied in 23 IL-2 treated patients with metastatic renal cell carcinoma. Eleven patients were complete responders (CR) and 12 were nonresponders (NR). In the CR group, 4/11 (40%) were diploid and 7/11 (60%) were aneuploid. In the NR group, 9/12 (75%) were diploid and 3/12 (25%) were aneuploid. Although there was a trend that patients with an aneuploid DNA pattern were more likely to undergo a complete response, ploidy pattern alone was not significantly predictive of response (p2 = 0.10, Fischer's exact test). When combining ploidy pattern with other variables that were predictive for complete response, such as good performance status and a higher pretreatment weight, prediction of complete response was not improved by including ploidy. This preliminary report suggests that DNA ploidy does not appear to provide any additional information concerning responsiveness to IL-2 based immunotherapy beyond that obtained by performance status and pretreatment weight in this patient population.

Carcinoma, Renal Cell↗
PubMed1993

Cytoreductive surgery prior to interleukin-2-based therapy in patients with metastatic renal cell carcinoma.

From May 1985 to December 1990, 93 patients with the clinical diagnosis of metastatic renal cell carcinoma and their primary tumor in place were evaluated for cytoreductive surgery as preparation for systemic therapy with regimens based on interleukin-2. These patients had typical sites of metastatic disease and manifestations of paraneoplastic syndromes. Patients underwent removal of the primary tumor, as well as debulking when this could be performed safely. Thirty-two percent of patients (30/93) had a second surgical resection in addition to their nephrectomy, frequently because of the large size of the primary tumor and its invasion of adjacent structures. Thirteen percent of patients (12/93) experienced postoperative complications. There were no perioperative mortalities. Forty percent of patients (37/93) who underwent nephrectomy could not be treated with immunotherapy, usually because of progression of disease. A preoperative ECOG status greater than or equal to 2 was the only significant risk factor associated with failure to undergo immunotherapy (P = 0.043). The response rate to immunotherapy in the 56 patients receiving interleukin-2 was 27 percent (4 CR, 11 PR).

Adolescent↗
PubMed1993

Intraoperative ultrasound in the evaluation of tumor involvement of the inferior vena cava.

The successful excision of genitourinary malignancies extending to the inferior vena cava relies heavily on accurate preoperative imaging. For the majority of these patients magnetic resonance imaging, inferior venacavography, abdominal ultrasound or abdominal computerized tomography will reliably predict the extent of inferior vena caval involvement by tumor. However, occasionally the results of these studies will conflict or be called into question intraoperatively. We report on 8 patients considered to be at risk for inferior vena caval involvement by tumor and for whom intraoperative ultrasound was obtained to clarify the presence or extent of thrombus. Five patients had renal cell carcinoma and 3 had adrenal carcinoma. In all patients concern as to the extent or presence of tumor was based on either inconclusive preoperative studies or unexpected intraoperative findings. In each case intraoperative ultrasound clearly visualized the inferior vena cava and established the presence or extent of tumor invasion. In 4 patients venacavotomy was avoided as a consequence of these findings. Intraoperative ultrasound is a useful tool that can accurately assess the inferior vena cava for possible tumor invasion, especially when the presence or extent of tumor involvement is not definitively established preoperatively.

Adolescent↗
PubMed1993

The management of isolated renal recurrence of renal cell carcinoma following complete response to interleukin-2 based immunotherapy.

The role of interleukin-2 based immunotherapy in advanced renal cell carcinoma is gradually expanding. Among patients who achieve significant responses to these regimens the subsequent development of isolated recurrences raises difficult management questions. We report 2 unusual cases of isolated recurrence in the remaining kidney following a sustained, complete response to interleukin-2 based adoptive immunotherapy. Both patients were treated with interleukin-2 based therapy following surgical resection of the primary renal tumor. The disease course of each patient is described and the literature is reviewed. Both patients were free of disease after relatively short-term followup. Surgery for patients with limited recurrence of renal cell carcinoma following an objective response to immunotherapy may, in select cases, be a reasonable treatment alternative.

Carcinoma, Renal Cell↗
PubMed1993

Regression of metastatic renal cell carcinoma after cytoreductive nephrectomy.

Fewer than 1% of patients with renal cell carcinoma are reported to experience spontaneous regression of metastatic lesions after nephrectomy. We report on 4 of 91 patients (4.4%) with metastatic renal cell carcinoma who had spontaneous regression of all metastatic lesions after cytoreductive nephrectomy. These patients were carefully selected before surgery for the ability to receive high dose interleukin-2. One patient had recurrence at 2 months, 1 had recurrence at 11 months, and 2 had no evidence of disease at 3 and 4.5 years.

Carcinoma, Renal Cell↗
PubMed1993

Mapping the Von Hippel-Lindau disease tumour suppressor gene: identification of germline deletions by pulsed field gel electrophoresis.

Von Hippel-Lindau (VHL) disease is a dominantly inherited familial cancer syndrome in which affected individuals have a greatly increased predisposition to the development of haemangioblastomas of the central nervous system and retina, renal cell carcinoma and phaeochromocytoma. The VHL gene has been mapped to chromosome 3p25-p26 by genetic linkage studies and we have previously demonstrated that the VHL gene is tightly linked to the D3S601 locus (Zmax = 18.86 at theta = 0.0) suggesting that D3S601 maps close to the VHL disease gene. We have constructed a long range physical map around D3S601 and screened 91 VHL patients from 80 kindreds for germline rearrangements using pulsed field gel electrophoresis. Two patients showed abnormal fragments in Mlul digested DNA probed with D3S601. Further analysis was consistent with both patients having germline deletions (approximately 120 kb and 50 kb) telomeric to D3S601. These results have (i) established the position of the VHL disease gene with respect to D3S601, (ii) refined the localisation of the VHL disease gene to a small region (approximately 50 kb) of chromosome 3p25-p26 and (iii) excluded the plasma membrane Ca(+)+-transporting ATPase isoform 2 (PMCA-2) gene as a candidate gene for VHL disease.

Chromosome Mapping↗
PubMed1993

Molecular genetic studies of sporadic and familial renal cell carcinoma.

Renal cell carcinoma (RCC) occurs predominantly as a sporadic disease but has familial forms. Cytogenetic and DNA deletion analyses show that both sporadic and familial RCC tumors arise as the result of chromosomal deletions in the 3p13-p26 region. von Hippel-Lindau (VHL) disease is a hereditary, multifocal syndrome that includes, among several affected organs, multiple, bilateral renal cysts and RCC. Although the VHL disease gene maps to chromosome 3p25-p26, data indicate that the VHL and sporadic RCC disease genes are likely to be independent. The authors hypothesize that VHL disease manifestations are controlled by mutations in the VHL disease gene and that the onset of VHL-associated kidney cancer is due to a second mutation of the linked sporadic RCC gene.

Carcinoma, Renal Cell↗
PubMed1993

Iodine-131-metaiodobenzylguanidine scintigraphy in preoperative and postoperative evaluation of paragangliomas: comparison with CT and MRI.

Iodine-131-metaiodobenzylguanidine (MIBG) scintigraphy, transmission computed tomography and magnetic resonance imaging were used to evaluate 36 patients with clinically suspected functioning paragangliomas. The patients were divided into two groups. In Group 1 (n = 21), studied before surgery, patients mainly had benign adrenal disease. In Group 2 (n = 15), studied after surgery, patients frequently had malignant or extra-adrenal tumors. In Group 1, transmission computed tomography and magnetic resonance imaging were more sensitive (100% for both) than MIBG scintigraphy (82%), which, however, was the most specific (100%). In Group 2, MIBG scintigraphy and magnetic resonance imaging were more sensitive (83% for both) than transmission computed tomography (75%), but MIBG was again the most specific (100%). Thus, all three were complementary modalities for localizing paragangliomas both preoperatively and postoperatively. MIBG imaging is indicated for both groups but it is especially recommended for postsurgical patients with recurrence because the disease is often malignant or extra-adrenal.

3-Iodobenzylguanidine↗