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J A Roth

Publications and source records attributed to J A Roth.

At least 109 records · Page 6Linked to original sources
PubMed1999

A multidisciplinary surgical approach to superior sulcus tumors with vertebral invasion.

BACKGROUND: Vertebral body invasion by superior sulcus tumor has traditionally been considered a contraindication to surgical resection. Attempts at definitive radiation or chemoradiation have not been successful. Recent advances in spinal instrumentation have allowed more complete resection of vertebral body tumors. We, therefore, reviewed our recent experience with vertebral resection of superior sulcus tumors. METHODS: All patients (n = 17) undergoing resection of superior sulcus tumors with T4 involvement of the vertebrae from October 18, 1990 to September 21, 1998 at the University of Texas M.D. Anderson Cancer Center (MDACC) were evaluated. Their clinical and pathologic data were reviewed and analyzed for short- and long-term outcomes. RESULTS: Total vertebrectomy was performed in 7 patients (42%), partial vertebrectomy in 7 (42%), and 3 (18%) underwent neural foramina or transverse process resection. The median hospital stay was 11 days. Postoperative complications occurred in 7 patients (42%) and included pneumonia (6, 36%), arrhythmia (2, 12%), cerebrospinal fluid leak (2, 12%), wound breakdown (1, 6%), and reoperation for bleeding (1, 6%). Sixteen out of 17 patients received preoperative or postoperative radiation therapy. No perioperative mortality occurred. All patients remained ambulatory after spinal reconstruction. Overall actuarial survival at 2 years was 54%, with 11 patients still alive 2 to 50 months after resection. Locoregional tumor recurrence was noted in all 6 patients who had positive surgical margins, as opposed to 1 out of 11 patients (9%) with negative margins (p < 0.006). Additionally, the 2-year actuarial survival of patients with negative microscopic margins was 80% versus 0% for positive margins (p < 0.0006). CONCLUSIONS: An aggressive multidisciplinary approach to superior sulcus tumors with vertebral invasion can lead to long-term survival with acceptable morbidity if negative margins can be obtained. Vertebral body invasion should no longer be considered a contraindication for resection of superior sulcus tumors.

Adult↗
PubMed1999

Mechanistic bases for adverse vaccine reactions and vaccine failures.

Mild local and systemic reactions to vaccines are to be expected as a natural consequence of vigorously stimulating the immune system. Dramatic adverse reactions to vaccines are occasionally due to mistakes during the production or handling of vaccines. More often, they are due to not following label instructions, particularly the restriction to only use vaccines in healthy animals. It is important to publish well-documented instances of adverse vaccine reactions so that producers and users of vaccines can all learn from the experience and avoid similar problems. Vaccine failure to protect from disease is usually due to problems with either client education or compliance with good animal management practices. It is important for clients to understand the proper timing and method of vaccine administration, what to realistically expect for vaccine efficacy, and the importance of minimizing immunosuppressive factors and exposure to high doses of infectious agents in vaccinated animals. Veterinary vaccines have produced dramatic benefits in terms of animal health, human health, and efficiency of food production. Advances in research and the accumulating experience with vaccines are leading to safer and more effective vaccines. Proper usage of vaccines and adherence to good management practices will continue to be essential to achieve maximal vaccine safety and efficacy.

Animal Husbandry↗
PubMed1999

Overexpression of the p21 sdi1 gene induces senescence-like state in human cancer cells: implication for senescence-directed molecular therapy for cancer.

Normal cells in a culture enter a nondividing state after a finite number of population doubling, which is termed replicative senescence, whereas cancer cells have unlimited proliferative potential and are thought to exhibit an immmortal phenotype by escaping from senescence. The p21 gene (also known as sdi1), which encodes the cyclin-dependent kinase inhibitor, is expressed at high levels in senescent cells and contributes to the growth arrest. To examine if the p21sdi1 gene transfer could induce senescence in human cancer cells, we utilized an adenoviral vector-based expression system and four human cancer cell lines differing in their p53 status. Transient overexpression of p21sdi1 on cancer cells induced quiescence by arresting the cell cycle at the G1 phase and exhibited morphological changes, such as enlarged nuclei as well as a flattened cellular shape, specific to the senescence phenotype. We also showed that p21sdi1-transduced cancer cells expressed beta-galactosidase activity at pH 6.0, which is known to be a marker of senescence. Moreover, the polymerase chain reaction-based assay demonstrated that levels of telomerase activity were significantly lower in p21sdi1-expressing cells compared to parental cancer cells. These observations provide the evidence that p21sdi1 overexpression could induce a senescence-like state and reduce telomerase activity in human cancer cells, suggesting that these novel p21sdi1 functions may have important implications for anticancer therapy.

Adenoviridae↗
PubMed1999

Reduced toxicity, attenuated immunogenicity and efficient mediation of human p53 gene expression in vivo by an adenovirus vector with deleted E1-E3 and inactivated E4 by GAL4-TATA promoter replacement.

A recombinant adenovirus with deleted E1 and E3, and E4-inactivated by replacing the E4 promoter with a synthetic promoter composed of a minimal TATA box and five consensus yeast GAL4-binding site elements was developed and used to express the human tumor suppresser gene p53. The toxicity and immunogenicity of this vector and vector-mediated p53 gene expression in vivo were studied in immunocompetent C3H and C57BL/6 mice. Expression of the late viral gene product, hexon protein, was observed in C3H and C57BL/6 mice injected with E4 wild-type adenovirus constructs Adv-cmv-beta-Gal (BG), Adv-cmv-hp53 (WT), and empty E1- vector Adv-E4 (EW) 3 to 28 days after injection, but was undetectable in mice treated with E4 modified empty E1- vector Adv-GAL4 (EG) or Adv-cmv-hp53-GAL4 (G4). Expression of the p53 gene was observed in both WT- and G4-injected C3H and C57BL/6 mouse livers from days 3 to 28. Ten weeks after injection, p53 gene expression was still detected in G4-treated C57BL/6 mice at similar levels, but was not detectable in WT-treated mice. Vector-induced liver toxicity was evaluated by analyzing serum transaminases (SGOT and SGPT) activities. In all cases, SGOT and SGPT activities were markedly decreased in EG-treated C3H and C57BL/6 mice compared with those in EW-treated mice on days 3, 7 and 14 after injection. In C57BL/6 mice, the total anti-adenoviral CTL activities were two- to three-fold higher in animals treated with EW vector than in those treated with EG vector. These results suggest that inactivation of the E4 promoter efficiently diminished the viral replication and the late viral gene expression, reduced host immune response and consequently reduced toxicity and prolonged the duration of transgene expression in vivo.

Adenoviridae↗
PubMed1999

Antigen-specific in vitro activation of T-lymphocyte subsets of cattle immunized with a modified live bovine herpesvirus 1 vaccine.

Bovine peripheral blood mononuclear cells from cattle immunized with a modified live virus bovine herpesvirus 1 (BHV1) vaccine and from BHV1-negative cattle were incubated in vitro with inactivated BHV1 for 6 days. Activation of T-lymphocyte subsets was measured by two-color flow cytometric analysis of T-cell phenotype and surface expression of CD25, the alpha-subunit of the high-affinity interleukin-2 receptor. Vaccinated animals, but not unvaccinated animals, had CD3+, CD4+, and gamma-delta T cells that significantly (p < 0.05) increased expression of CD25 when incubated with BHV1. CD8+ T cells from vaccinated animals did not consistently increase CD25 expression when incubated with inactivated BHV1.

Animals↗
PubMed1999

Potent antitumor activity of 2-methoxyestradiol in human pancreatic cancer cell lines.

We examined the effect of 2-methoxyestradiol (2-ME) on the growth and tumorigenesis of human pancreatic cancer cells. 2-ME inhibited the growth of these cell lines (50-90%) in a dose- and time-dependent fashion, and terminal deoxynucleotidyl transferase staining showed that it induced apoptotic cell death. Flow cytometric analysis indicated that 2-ME-sensitive cells showed a prolonged S phase after 48 h of treatment. We used a mouse model for in vivo studies of lung metastasis and injected MIA PaCa-2 cells into the tail veins of nu/nu mice; lung colonies were formed. Mice given oral 2-ME showed 60% inhibition in the number of lung colonies compared with control, untreated animals. These results suggest that 2-ME may have clinical application for the treatment of pancreatic cancer.

2-Methoxyestradiol↗
PubMed1999

Recombinant adenovirus expressing wild-type p53 is antiangiogenic: a proposed mechanism for bystander effect.

Angiogenesis is required for the growth and progression of malignancies. Recent studies have demonstrated that genetic alterations may accompany acquisition of the angiogenic phenotype. The tumor suppressor gene p53 is most frequently mutated in human cancers and is also known to be a transcriptional regulator of a variety of genes. Here, we investigated the antiangiogenic effect of the wild-type p53 (wt-p53) gene transfer on a human non-small cell lung cancer cell line. Mutant p53-expressing H226Br non-small cell lung cancer cells were transduced with the wt-p53 gene using a recombinant adenoviral vector (Ad5CMVp53) and applied to semiquantitative reverse transcription-PCRs for the detection of altered mRNA expression of angiogenic and/or antiangiogenic factors. In vivo neovascularization assay of Ad5CMVp53-infected cells was then performed using a membrane-diffusion chamber system s.c. transplanted in nu/nu mice. We also evaluated the effect of Ad5CMVp53-infected H226Br cells on nontransduced tumor cells in vivo by s.c. inoculating mixture of cells into nu/nu mice. Ad5CMVp53 infection markedly inhibited the expression of an angiogenic factor, vascular endothelial growth factor, and increased the expression of a novel antiangiogenic factor, brain-specific angiogenesis inhibitor 1, resulting in reduced neovascularization in vivo. Mixing experiments showed that tumor cells transduced with the wt-p53 gene inhibited the in vivo tumor growth of adjacent nontransduced cells. Our data suggest that a recombinant adenovirus expressing the wt-p53 gene is antiangiogenic, which may explain, in part, the mechanism of the bystander effect induced by the wt-p53 gene transfer on adjacent tumor cells.

Adenoviruses, Human↗
PubMed1999

p53 tumor suppressor gene therapy for cancer.

Gene therapy has the potential to provide cancer treatments based on novel mechanisms of action with potentially low toxicities. This therapy may provide more effective control of locoregional recurrence in diseases like non-small-cell lung cancer (NSCLC) as well as systemic control of micrometastases. Despite current limitations, retroviral and adenoviral vectors can, in certain circumstances, provide an effective means of delivering therapeutic genes to tumor cells. Although multiple genes are involved in carcinogenesis, mutations of the p53 gene are the most frequent abnormality identified in human tumors. Preclinical studies both in vitro and in vivo have shown that restoring p53 function can induce apoptosis in cancer cells. High levels of p53 expression and DNA-damaging agents like cisplatin (Platinol) and ionizing radiation work synergistically to induce apoptosis in cancer cells. Phase I clinical trials now show that p53 gene replacement therapy using both retroviral and adenoviral vectors is feasible and safe. In addition, p53 gene replacement therapy induces tumor regression in patients with advanced NSCLC and in those with recurrent head and neck cancer. This article describes various gene therapy strategies under investigation, reviews preclinical data that provide a rationale for the gene replacement approach, and discusses the clinical trial data available to date.

Animals↗
PubMed1999

Factors limiting adenovirus-mediated gene transfer into human lung and pancreatic cancer cell lines.

Adenoviral vectors are a widely used means of gene transfer. However, transgene expression after adenoviral administration varies among different carcinoma cell lines. We hypothesized that this variation is attributable, in part, to the presence of cell surface molecules involved in adenoviral infection. To test this, we first assessed adenovirus-mediated transgene expression in four human lung carcinoma cell lines and four human pancreatic carcinoma cell lines in terms of luciferase activities and found it to vary from 4.8 x 10(4) to 6.1 x 10(7) relative light units/microg of protein. Then, to determine whether the molecules involved in the entry of adenovirus into host cells were responsible for this variation, we evaluated the expression of alpha(v)beta5, alpha(v), beta3, alpha5, and beta1 integrins and that of coxsackievirus and adenovirus receptor (CAR) in these cell lines. Statistical analysis revealed that the levels of beta3 were associated with the levels of transgene expression. Blocking analysis showed that adenovirus-mediated gene transfer could be blocked by antibodies against these six molecules but not by the antibodies against alpha2 or alpha3 integrins, thus suggesting that the integrins alphavbeta5, alpha(v), beta3, alpha5, and beta1 and CAR molecules could limit adenovirus-mediated gene transfer when their levels fell below a certain threshold. Furthermore, cells expressing low levels of beta3 and resistant to conventional adenoviral vectors were susceptible to a vector containing the heparin-binding domain in its fiber, thus suggesting that redirecting vectors to receptors other than CAR may bypass the integrin pathway. These findings may have implications for improving the efficiency of adenovirus-mediated gene transfer and developing novel adenoviral vectors.

Adenoviruses, Human↗
PubMed1999

Induction of differentiation-dependent apoptosis in human esophageal squamous cell carcinoma by adenovirus-mediated p21sdi1 gene transfer.

When keratinocytes withdraw from the cell cycle, they migrate from the basal to the superficial layers of the epidermis and undergo morphological and biochemical changes during the process of terminal differentiation. These differentiation features of keratinocytes are known to be altered or reduced in esophageal cancer cells. Therefore, we examined the effects of transferring the cyclin-dependent kinase inhibitor p21sdi1 gene into human esophageal cancer cell lines as well as normal keratinocytes using an adenovirus vector system. Ectopic expression of p21sdi1 protein resulted in cell cycle arrest at the G1 phase and produced morphological changes, such as enlarged nuclei and a flattened cellular shape, changes specific to the differentiated phenotype. The human involucrin protein is a specific product of keratinocyte differentiation, which is selectively expressed in the suprabasal epidermal layers. Western blot analysis and immunohistochemical staining demonstrated that involucrin expression was 3- to 5-fold enhanced by the forced expression of p21sdi1 in esophageal cancer cells, whereas only a mild up-regulation up to 1.2-fold occurred in normal keratinocytes. We also found that exogenous introduction of the p2sdi1 gene transcriptionally activated the upstream promoter function of the involucrin gene. These stimulatory effects on involucrin expression were not observed when another cyclin-dependent kinase inhibitor gene, p16(INK4a), was transduced. Moreover, p21sdi1 expression in esophageal cancer cells transduced with p21sdi1 led to a rapid apoptotic cell death after a transient dormant phase, although keratinocytes transduced with p21sdi1 survived longer by terminally withdrawing from the cell cycle. These results may have an important implication for understanding the biology of differentiation-dependent apoptosis in human esophageal squamous cell carcinoma.

Adenoviruses, Human↗
PubMed1998

Chemotherapy followed by surgery compared with surgery alone for localized esophageal cancer.

BACKGROUND: We performed a multi-institutional randomized trial comparing preoperative chemotherapy followed by surgery with surgery alone for patients with local and operable esophageal cancer. METHODS: Preoperative chemotherapy for patients randomly assigned to the chemotherapy group included three cycles of cisplatin and fluorouracil. Surgery was performed two to four weeks after the completion of the third cycle; patients also received two additional cycles of chemotherapy after the operation. Patients randomly assigned to the immediate-surgery group underwent the same surgical procedure. The main end point was overall survival. RESULTS: Of the 440 eligible patients with adequate data , 213 were assigned to receive preoperative chemotherapy and 227 to undergo immediate surgery. After a median possible study time of 55.4 months, there were no significant differences between the two groups in median survival: 14.9 months for the patients who received preoperative chemotherapy and 16.1 months for those who underwent immediate surgery (P=0.53). At one year, the survival rate was 59 percent for those who received chemotherapy and 60 percent for those who had surgery alone; at two years, survival was 35 percent and 37 percent, respectively. The toxic effects of chemotherapy were tolerable, and the addition of chemotherapy did not appear to increase the morbidity or mortality associated with surgery. There were no differences in survival between patients with squamous-cell carcinoma and those with adenocarcinoma. Weight loss was a significant predictor of poor outcome (P=0.03). With the addition of chemotherapy, there was no change in the rate of recurrence at locoregional or distant sites. CONCLUSIONS: Preoperative chemotherapy with a combination of cisplatin and fluorouracil did not improve overall survival among patients with epidermoid cancer or adenocarcinoma of the esophagus.

Adenocarcinoma↗
PubMed1998

Gene therapy and pancreatic cancer.

Adenocarcinoma of the pancreas is associated with a short survival due to frequent delays in diagnosis and the lack of effective systemic therapies. Advances in understanding the molecular basis of pancreatic cancer have allowed identification of molecular targets which are amenable to therapeutic intervention. Such targets include p53, K-ras, p16, and DPC-4. Gene therapy involves the transfer of genetic constructs which alter the neoplastic potential of the cancer cell. Vectors used in gene transfer include viral and non-viral methods. Presently, gene therapy of pancreatic cancer is limited to pre-clinical studies using in vitro and in vivo models. However, the initial results from these pre-clinical studies have been encouraging and will form the basis for clinical studies of gene transfer in patients with pancreatic cancer.

Adenocarcinoma↗
PubMed1998

An agent that increases tumor suppressor transgene product coupled with systemic transgene delivery inhibits growth of metastatic lung cancer in vivo.

Low levels of gene expression following systemic delivery have impaired the effectiveness of tumor suppressor gene replacement in treating metastases. We asked whether combined treatment with 2-methoxyestradiol (2-Me), which increases levels of wild-type p53 protein in cancer cells, and the systemic administration of an adenoviral vector expressing wild-type p53 (Ad-p53) would inhibit the growth of human metastatic lung cancer cells in vivo. The simultaneous administration of p53 and 2-Me resulted in a greater than additive reduction with the lung colony count reduced to 33% of its control value. These results suggest that the synergistic effect of 2-Me and Ad-p53 in combination treatment may have application in the systemic treatment of cancer.

2-Methoxyestradiol↗
PubMed1998

Reduced telomeric signals and increased telomeric associations in human lung cancer cell lines undergoing p53-mediated apoptosis.

Transduction of a p53-negative H1299 human non-small cell lung cancer cell line with an adenoviral vector containing wild-type p53 (Ad5p53) induced apoptosis. Analysis of the Ad5p53-infected H1299 cells showed high levels of telomeric association prior to apoptotic nuclear fragmentation. Similar telomeric association was observed in stably transfected clones of the wtH226b cell line, which expressed exogenous wild-type p53 protein and also showed complex chromosomal abnormalities including dicentrics, rings and fragments. Fluorescence in situ hybridization (FISH) analysis using a human telomeric DNA probe indicated reductions in telomere signals in both Ad5p53-infected H1299 cells and wtH226b-S cells. In contrast, stably transfected wtH226b-AS clones expressing antisense p53 cDNA showed no telomeric association and had high levels of telomeric signals associated with a faster growing phenotype. These results suggest that wild-type p53 is involved in shortening telomeres, a possibly early event in the p53-mediated apoptotic process and in the subsequent telomeric association that predisposes a cell to genetic instability and DNA fragmentation resulting in apoptotic cell death. Moreover, loss of telomeric signals may indicate a cell's decision to undergo programmed cell death and, if so, could, serve as a sensitive marker of p53-mediated apoptosis.

Adenoviruses, Human↗
PubMed1998

Increased MHC class II and CD25 expression on lymphocytes in the absence of persistent lymphocytosis in cattle experimentally infected with bovine leukemia virus.

We recently observed that a group of cattle experimentally infected with bovine leukemia virus (BLV) had enhanced antibody responses to recall antigens. None of the cattle in this group were classified as persistently lymphocytotic, but they did have significantly increased numbers of circulating T and B cells. In order to investigate the potential mechanisms of BLV-induced immune activation, dual-color flow cytometry was used to compare the expression of MHC class II (MHC II) molecules and the inducible IL-2 receptor alpha chain, CD25, on lymphocyte subsets in freshly isolated and cultured PBMC from these same BLV-infected cattle (n=5) with that of age-matched, uninfected controls (n=3). Freshly isolated peripheral blood mononuclear cells (PBMC) from BLV-infected cattle were found to contain a significantly higher percentage of B cells that expressed MHC II molecules (p<0.01). In addition, an increased proportion of CD4+ T cells from BLV-infected cattle expressed MHC II molecules after 20 h of Concanavalin A (Con A) stimulation (p<0.05), and MHC II expression was increased on both CD4+ (p<0.01) and CD8+ (p<0.05) T cells from BLV-infected cattle after 68 h in vitro, even in the absence of exogenous mitogen. Although CD25 expression was not increased on freshly isolated lymphocytes from BLV-infected cattle, an increased percentage of B cells from BLV-infected cattle expressed CD25 after 20 h of culture, either in the presence (p<0.05) or absence (p<0.01) of Con A. Thus, in addition to causing alterations in absolute numbers of circulating lymphocytes, BLV infection appears to cause a functional activation of both B and T cells, even in cattle that are non-lymphocytotic. It is likely that these BLV-induced alterations in lymphocyte activation status contributed to the previously observed enhancement of antibody responses in vivo.

Animals↗
PubMed1998

Effects of long-term infection with bovine immunodeficiency virus and/or bovine leukemia virus on antibody and lymphocyte proliferative responses in cattle.

Immune responses were examined in cattle between 3-5 years after experimental inoculation with bovine immunodeficiency virus (BIG) and/or bovine leukemia virus (BLV). Lymphocyte proliferative responses to Con A or to allogeneic lymphocytes with foreign major histocompatibility complex molecules (allo MHC) were determined by 3H-thymidine incorporation assays. Antigen-specific antibody and lymphocyte proliferative responses were measured following vaccination with tetanus toxoid (TT) and bovine herpes virus-1 (BHV-1). Lymphocytes from BIV-infected cattle had significantly (p<0.05) reduced proliferative responses to Con A, but responses to allo-MHC and TT did not differ from those of uninfected controls. BIV infection also had little effect on TT-specific antibody responses in vivo. In contrast, BLV-infected cattle had significantly increased secondary antibody responses to vaccination with TT, as well as enhancement of antibody responses to BHV-1. Co-infection with BIV did not alter the BLV effect, suggesting a lack of significant interaction between the two viruses in vivo. Numbers of circulating mononuclear cells were also higher in BLV-infected cattle, which was attributable to increases in both T and B cell numbers. Unstimulated lymphocytes from BLV-infected cattle had significantly increased spontaneous uptake of 3H-thymidine in vitro. When differences in counts per minute were analyzed, lymphocytes from BLV-infected cattle had slightly increased proliferative responses to Con A, but no consistent alternations in responsiveness to allo-MHC, TT, or BHV-1. The observed increase in antibody responses to non-BLV antigens suggests that at least in clinically asymptomatic cattle, BLV infection may cause a non-specific B cell activation.

Animals↗
PubMed1998

Superinduction of wild-type p53 protein after 2-methoxyestradiol treatment of Ad5p53-transduced cells induces tumor cell apoptosis.

Because 2-methoxyestradiol (2-MeOE2) induces and stabilizes wild-type p53 protein (wt p53) in human lung cancer cell lines posttranscriptionally, we sought to study its effects on Ad5p53-transduced lung cancer cell lines at a low multiplicity of infection (1 MOI). Treating these cells with 2-MeOE2 resulted in superinduction of wt p53 protein expression followed by apoptosis, as shown by terminal deoxynucleotidyl transferase (TdT) staining, and upregulation of wt p53 expression, as shown by Western blot analysis. When transduced with Ad5p53 alone at 1 MOI, the cell lines grew rapidly. Moreover, adenoviral-vector-mediated p53 gene transfer followed by 2-MeOE2 treatment caused 80% growth inhibition in the cell lines regardless of their p53 status. Thus, p53 superinduction and apoptosis after 2-MeOE2 treatment in Ad5p53-transduced cells appears to be a unique strategy with significant implications for cancer gene therapy.

2-Methoxyestradiol↗