Biomedical subjects

G L Walsh

Publications and source records attributed to G L Walsh.

At least 37 records · Page 2Linked to original sources

PubMed2000

Adenovirus-mediated p53 gene transfer in sequence with cisplatin to tumors of patients with non-small-cell lung cancer.

PURPOSE: To determine the safety and tolerability of adenovirus-mediated p53 (Adp53) gene transfer in sequence with cisplatin when given by intratumor injection in patients with non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Patients with advanced NSCLC and abnormal p53 function were enrolled onto cohorts receiving escalating dose levels of Adp53 (1 x 10(6) to 1 x 10(11) plaque-forming units [PFU]). Patients were administered intravenous cisplatin 80 mg/m(2) on day 1 and study vector on day 4 for a total of up to six courses (28 days per course). Apoptosis was determined by the terminal deoxynucleotidyl- transferase-dUTP nick-end labeling assay. Evidence of vector-specific sequences were determined using reverse-transcriptase polymerase chain reaction. Vector dissemination and biodistribution was monitored using a series of assays (cytopathic effects assay, Ad5 hexon enzyme-linked immunosorbent assay, vector-specific polymerase chain reaction assay, and antibody response assay). RESULTS: Twenty-four patients (median age, 64 years) received a total of 83 intratumor injections with Adp53. The maximum dose administered was 1 x 10(11) PFU per dose. Transient fever related to Adp53 injection developed in eight of 24 patients. Seventeen patients achieved a best clinical response of stable disease, two patients achieved a partial response, four patients had progressive disease, and one patient was not assessable. A mean apoptotic index between baseline and follow-up measurements increased from 0.010 to 0.044 (P =.011). Intratumor transgene mRNA was identified in 43% of assessable patients. CONCLUSION: Intratumoral injection with Adp53 in combination with cisplatin is well tolerated, and there is evidence of clinical activity.

Adenoviruses, Human↗

PubMed2000

Coaxial double-lumen methylmethacrylate reconstruction in the anterior cervical and upper thoracic spine after tumor resection.

OBJECT: A unique method of anterior spinal reconstruction after decompressive surgery was used to prevent methylmethacrylate-dural contact in cancer patients who underwent corpectomy. The purpose of this study was to assess the efficacy and stability of polymethylmethacrylate (PMMA) anterior surgical constructs in conjunction with anterior cervical plate stabilization (ACPS) in these patients. METHODS: Approximately 700 patients underwent spinal surgery at The University of Texas M. D. Anderson Cancer Center over a 4-year period. The authors conducted a retrospective outcome study for 29 of these patients who underwent anterior cervical or upper thoracic tumor resections while in the supine position. These patients were all treated using the coaxial, double-lumen, PMMA technique for anterior spinal reconstruction with subsequent ACPS. No postoperative external orthoses were used. Twenty-seven patients (93%) harbored metastatic spinal lesions and two (7%) harbored primary tumors. At 1 month postsurgery, significant improvement was seen in spinal axial pain (p<0.001), radiculopathy (p<0.001), gait (p = 0.008), and Frankel grade (p = 0.002). A total of nine patients (31%) underwent combined anterior-posterior 360 degrees stabilization. Twenty-one patients (72%) experienced no complications. Complications related to instrumentation failure occurred in only two patients (7%). There were no cases in which the patients' status worsened, and there were no neurological complications or infections. The median Kaplan-Meier survival estimate for patients with spinal metastases was 9.5 months. At the end of the study, 13 patients (45%) had died and 16 (55%) were alive. Postoperative magnetic resonance images consistently demonstrated that the dura and PMMA in all patients remained separated. CONCLUSIONS: The anterior, coaxial, double-lumen, PMMA reconstruction technique provides a simple means of spinal cord protection in patients in the supine position while undergoing surgery and offers excellent results in cancer patients who have undergone cervical vertebrectomy.

Adult↗

PubMed2000

N-(4-hydroxyphenyl)retinamide in the chemoprevention of squamous metaplasia and dysplasia of the bronchial epithelium.

Lung cancer remains the number one cause of cancer-related deaths in the United States. To reduce the mortality associated with this disease, individuals at risk must be identified prior to the development of lung cancer, and effective prevention strategies must be developed. One such strategy is to use retinoids like N-(4-hydroxyphenyl)retinamide (4-HPR), which has been found to possess chemopreventive activities in preclinical studies. In this study, 139 smokers were registered and 82 were randomized onto a double-blinded, placebo-controlled chemoprevention trial of 4-HPR administered p.o. (200 mg once daily). Of these, 70 participants were eligible for response evaluation. Biopsies were obtained at six predetermined sites in the bronchial tree from participants before and at the completion of 6 months of treatment. 4-HPR treatment had no measurable effect on histopathology (squamous metaplasia and dysplasia) in the bronchial epithelium of current smokers. 4-HPR was detected (104.5+/-64.0 ng/ml, mean +/- SD) in the serum of participants, supporting its potential bioavailability. Serum retinol levels decreased markedly (44% of placebo-treated patients) as a consequence of 4-HPR treatment. Notably, the mRNA level of retinoic acid receptor beta, which is typically increased by retinoid treatment, did not change in the bronchial epithelium of 4-HPR-treated participants. Clonal populations of bronchial epithelial cells were detected by analysis of loss of heterozygosity at putative tumor suppressor loci on chromosomes 3p, 9p, and 17p, and these changes were not altered by 4-HPR treatment. In conclusion, at this dose and schedule, 4-HPR was not effective in reversing squamous metaplasia, dysplasia, or genetic and phenotypic abnormalities in the bronchial epithelium of smokers.

Adult↗

PubMed2000

C-CAM1, a candidate tumor suppressor gene, is abnormally expressed in primary lung cancers.

Previous studies have shown that the expression of the cell-cell adhesion molecule (C-CAM1), located at chromosome 19, is down-regulated in several types of human cancers, including prostate and breast cancers. Two major isoforms of C-CAM1, the long or L-form C-CAM1 and the short or S-form C-CAM1, are derived from the C-CAM1 gene through alternative splicing. Tumor cells transfected with L-form C-CAM1, which contains a cytoplasmic domain, display significantly lower growth rates and less tumorigenicity in both in vitro and in vivo models compared with untransfected tumor cells, suggesting that L-form C-CAM1 may be a tumor suppressor. The transfection of the cytoplasmic domain of L-form C-CAM1 could also cause suppression of tumor growth, further supporting the role of L-form C-CAM1 in tumorigenesis. In contrast to reports of most of the tumor types tested, Ohwada et al. (Am. J. Respir. Cell Mol. Biol., 11: 214-220, 1994) reported that C-CAM1 was not down-regulated or even up-regulated in lung cancer. Because the cytoplasmic domain of L-form C-CAM1 is critical for the tumor suppressor function of C-CAM1, we hypothesized that switching of the isoform rather than down- regulation of C-CAM1 gene expression occurs during lung tumorigenesis. To test this hypothesis, we analyzed pairs of tumor tissue and corresponding normal-appearing lung tissue from 51 patients with non-small cell lung cancer (NSCLC) and 43 cell lines to determine expression profiles of L-form C-CAM1 and S-form C-CAM1 using reverse transcription-PCR. We found that L-form C-CAM1 was the predominant form (75%; 38 of 51) in normal-appearing lung tissue, whereas most (84%; 43 of 51) of the primary NSCLC tissue samples expressed predominantly S-form C-CAM1 (P < 0.0001). Similarly, 19 (79%) of the 24 NSCLC cell lines and 17 (85%) of the 20 small cell lung cancer cell lines expressed predominantly S-form C-CAM1. The frequent alteration of the C-CAM1 expression pattern suggests that C-CAM1 has an important role in lung tumorigenesis.

Adenosine Triphosphatases↗

PubMed2000

Phase I study of irinotecan and concurrent radiation therapy for upper GI tumors.

Irinotecan (Camptosar) is an active chemotherapeutic agent for lung, gastric, esophageal, and colorectal cancers and a potent radiosensitizer. This phase I study was designed to assess the maximum tolerated dose of weekly irinotecan combined with concurrent radiotherapy for patients with locally advanced, unresectable gastric, gastroesophageal junction, or esophageal cancer. Patients who received previous chemotherapy (excluding irinotecan) or who experienced recurrent cancer after surgery were eligible for this protocol. The total dose of radiation did not exceed 50.4 Gy (28 fractions of 1.8 Gy each). The starting dose level of irinotecan was 30 mg/m2 infused over 90 minutes given weekly for 5 weeks. Subsequent dose levels were increased in 10 mg/m2 increments to 40, 50, 60, and 70 mg/m2. Of 15 patients who have been enrolled to date, all are evaluable for toxicities and 12 for response. Major hematologic toxicities (grade 3/4) were neutropenia, chills, hemorrhage, and anemia. Grade 3/4 gastrointestinal toxicities included nausea, vomiting, dehydration, anorexia, and constipation. Other severe nonhematologic toxicities included fatigue, hypotension, and hypothermia, as well as cardiovascular toxicities. There was no severe diarrhea and no treatment-related deaths. Of the 12 evaluable patients, 7 (58%) responded, including 2 complete responses; 4 (30%) had no change and 1 had progressive disease. Survival ranged from 1 month to 15 months, with a median survival of 8 months. When the total dose of irinotecan given concurrently with radiotherapy was higher than 250 mg/m2, patients experienced significantly more severe grade 3/4 toxicities than with lower doses (P = .04), with no improvement in response rate. It was concluded that weekly doses of irinotecan of up to 60 mg/m2 with concurrent radiotherapy given over 5 weeks was feasible and demonstrated good response. This regimen did not cause severe diarrhea or pneumonitis, but neutropenia and fatigue were major toxicities. The study continues to accrue.

Adolescent↗

PubMed1999

Posttranslational mechanisms contribute to the suppression of specific cyclin:CDK complexes by all-trans retinoic acid in human bronchial epithelial cells.

Retinoids have demonstrated activity in the chemoprevention of aerodigestive tract cancer. Potentially contributing to their lung cancer chemopreventive effects, retinoids inhibit the growth of human bronchial epithelial (HBE) cells. We observed previously that all-trans retinoic acid (t-RA) arrests the growth of HBE cells in the G0 phase of the cell cycle through activation of retinoic acid receptor-dependent pathways, which enhances the association of E2F-4 with retinoblastoma protein family members, converting E2F into a transcriptional suppressor. In this study, we examined the mechanism by which t-RA blocks cell cycle progression in HBE cells and the possibility that this signaling event is blocked in non-small cell lung cancer (NSCLC) cells that are refractory to the growth inhibitory effects of t-RA. t-RA suppressed the expression and activity of cyclin D1, cyclin E, and cyclin-dependent kinases (CDK)-2 and CDK-4, increased expression of the CDK inhibitor p27, and shifted the retinoblastoma protein to a hypophosphorylated form. Posttranslational mechanisms contributed to the changes in CDK-2, CDK-4, and p27 levels, which, in the case of CDK-4, involved the ubiquitin-proteasome pathway. In contrast, despite retinoic acid receptor transcriptional activation, these signaling events did not occur in a NSCLC cell line that is refractory to growth inhibition by t-RA. These findings provide the first evidence that t-RA activates degradation of CDK-4 through the ubiquitin-proteasome pathway, a novel mechanism by which t-RA causes HBE cells to exit the cell cycle, and blockade of these signaling events may contribute to the development of retinoid resistance in NSCLC cells.

Anticarcinogenic Agents↗

PubMed1999

Adenovirus-mediated p53 gene transfer in advanced non-small-cell lung cancer.

BACKGROUND: Preclinical studies in animal models have demonstrated tumor regression following intratumoral administration of an adenovirus vector containing wild-type p53 complementary DNA (Ad-p53). Therefore, in a phase I clinical trial, we administered Ad-p53 to 28 patients with non-small-cell lung cancer (NSCLC) whose cancers had progressed on conventional treatments. METHODS: Patients received up to six, monthly intratumoral injections of Ad-p53 by use of computed tomography-guided percutaneous fine-needle injection (23 patients) or bronchoscopy (five patients). The doses ranged from 10(6) plaque-forming units (PFU) to 10(11) PFU. RESULTS: Polymerase chain reaction (PCR) analysis showed the presence of adenovirus vector DNA in 18 (86%) of 21 patients with evaluable posttreatment biopsy specimens; vector-specific p53 messenger RNA was detected by means of reverse transcription-PCR analysis in 12 (46%) of 26 patients. Apoptosis (programmed cell death) was demonstrated by increased terminal deoxynucleotide transferase-mediated biotin uridine triphosphate nick-end labeling (TUNEL) staining in posttreatment biopsy specimens from 11 patients. Vector-related toxicity was minimal (National Cancer Institute's Common Toxicity Criteria: grade 3 = one patient; grade 4 = no patients) in 84 courses of treatment, despite repeated injections (up to six) in 23 patients. Therapeutic activity in 25 evaluable patients included partial responses in two patients (8%) and disease stabilization (range, 2-14 months) in 16 patients (64%); the remaining seven patients (28%) exhibited disease progression. CONCLUSIONS: Repeated intratumoral injections of Ad-p53 appear to be well tolerated, result in transgene expression of wild-type p53, and seem to mediate antitumor activity in a subset of patients with advanced NSCLC.

Adenoviridae↗

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

Associations among telomerase activity, p53 protein overexpression, and genetic instability in lung cancer.

Genomic instability is a driving force for tumorigenesis. p53 and telomerase play central roles in maintaining genomic integrity. The purpose of this study was to assess the associations among p53 protein overexpression, telomerase activity and genetic instability in lung cancer. We found that telomerase activity was detectable in 80% of 100 lung tumours, but only 7.7% of 91 paired adjacent normal tissues. p53 protein was overexpressed in 63% of the tumours but only 2% of the normal tissues. p53 was overexpressed in 56 of the 80 (70%) tumour tissues with telomerase activity but only seven of the 20 (35%) without telomerase activity. p53 protein overexpression carried a 6.7-fold (95% confidence interval, 1.7-27.7) increased risk for positive telomerase activity after adjustment by age, sex, ethnicity, smoking status and family history of lung cancer. The mean in vitro bleomycin-induced breaks per cell (a marker of cancer susceptibility) was significantly higher (0.92) for patients who overexpressed p53 in lung tumour tissue than that for patients with no detectable p53 expression in lung tumour tissue (0.65). Our data suggest that p53 protein overexpression may be common in individuals genetically susceptible to carcinogen exposure. p53 status may be related to telomerase expression.

Adult↗

PubMed1999

Combined chest wall resection with vertebrectomy and spinal reconstruction for the treatment of Pancoast tumors.

OBJECT: Traditionally, superior sulcus tumors of the lung that involve the chest wall and spinal column have been considered to be unresectable, and historically, patients harboring these tumors have been treated with local radiation therapy with, at best, modest results. The value of gross-total resection remains unclear in this patient population; however, with the recent advances in surgical technique and spinal instrumentation, procedures involving more radical removal of such tumors are now possible. At The University of Texas M. D. Anderson Cancer Center, the authors have developed a new technique for resecting superior sulcus tumors that invade the chest wall and spinal column. They present a technical description of this procedure and results in nine patients in whom stage IIIb superior sulcus tumors extensively invaded the vertebral column. METHODS: These patients underwent gross-total tumor resection via a combined approach that included posterolateral thoracotomy, apical lobectomy, chest wall resection, laminectomy, vertebrectomy, anterior spinal column reconstruction with methylmethacrylate, and placement of spinal instrumentation. There were six men and three women, with a mean age of 55 years (range 36-72 years). Histological examination revealed squamous cell carcinoma (three patients), adenocarcinoma (four patients), and large cell carcinoma (two patients). The mean postoperative follow-up period was 16 months. All patients are currently ambulatory or remained ambulatory until they died. Pain related to tumor invasion improved in four patients and remained unchanged in five. In three patients instrumentation failed and required revision. There was one case of cerebrospinal fluid leakage that was treated with lumbar drainage and one case of wound breakdown that required revision. Two patients experienced local tumor recurrence, and one patient developed a second primary lung tumor. CONCLUSIONS: The authors conclude that in selected patients, combined radical resection of superior sulcus tumors of the lung that involve the chest wall and spinal column may represent an acceptable treatment modality that can offer a potential cure while preserving neurological function and providing pain control.

Adenocarcinoma↗

PubMed1999

A pilot clinical laboratory trial of paclitaxel and endobronchial brachytherapy in patients with non-small cell lung cancer.

Paclitaxel enhances microtubule assembly and causes a cell cycle arrest in mitosis, the most radiosensitive phase. We conducted this study to improve our understanding of paclitaxel effects in vivo and to determine the maximum tolerated dose of paclitaxel preceding endobronchial radiation therapy (brachytherapy). The treatment consisted of two cycles of paclitaxel infused over 24 hours followed by 192Ir brachytherapy; cycles were repeated every 3 weeks. Tumor samples were obtained at baseline, after each paclitaxel infusion, and 3 weeks after completion of therapy. Twenty-two non-small cell lung cancer patients with a documented endobronchial lesion were enrolled in the study and 20 patients received the therapy with different doses of paclitaxel, initially without and then later with granulocyte colony-stimulating factor (G-CSF) support (5 microg/kg subcutaneously on days 3 to 10). With the starting paclitaxel dose of 135 mg/m2, five of seven patients developed neutropenia and fever, which mandated a dose reduction to 120 mg/m2. At this dose level, three of three patients had neutropenic fever; thus, 120 mg/m2 of paclitaxel was considered above the maximum tolerated dose without G-CSF support. However, with G-CSF support the therapy was well-tolerated without dose-limiting toxicity and accrual is continuing at the paclitaxel 175-mg/m2 dose level. While no patient had achieved systemic tumor response, 11 patients achieved partial response of the endobronchial lesion, which represents 68.8% of 16 patients who received two courses of therapy and 91.8% of 12 patients who had full evaluation by bronchoscopy after completion of therapy. The in vivo paclitaxel effects were studied using the pre- and post-paclitaxel therapy tumor samples in eight patients. Four (50%) patients had a significant increase in mitotic cells after paclitaxel, as assessed by MPM-2 immunostaining that recognizes a large family of mitotic phosphoproteins. A substantial increase in the number of micronucleated apoptotic cells, another paclitaxel effect, was also found in six patients. These results clearly indicate that patients with endobronchial lesions from recurrent NSCLC could not tolerate this combined modality regimen without G-CSF support. However, this group of patients provided a unique opportunity to study in vivo paclitaxel effects in a clinical trial setting.

Aged↗

PubMed1998

A multidisciplinary approach to therapy for unresectable malignant thymoma.

BACKGROUND: The therapeutic outcome for unresectable, locally advanced, malignant thymoma has been poor. OBJECTIVE: To improve tumor resectability and patient survival rates by studying a multimodal approach to therapy for unresectable malignant thymoma. DESIGN: Prospective cohort study. SETTING: Tertiary care cancer center. PARTICIPANTS: All eligible patients had newly diagnosed, histologically proven, unresectable malignant thymoma. INTERVENTION: The treatment regimen consisted of induction chemotherapy (three courses of cyclophosphamide, doxorubicin, cisplatin, and prednisone), surgical resection, postoperative radiation therapy, and consolidation chemotherapy (three courses of cyclophosphamide, doxorubicin, cisplatin, and prednisone). Tissue samples were taken at the time of surgical resection for assessment of tumor necrosis and Ki-67 expression. MEASUREMENTS: Tumor response and resectability (both overall and after induction chemotherapy) and disease-free survival rate in patients who received multimodal therapy. RESULTS: 13 patients were consecutively enrolled from February 1990 to December 1996, and 12 evaluable patients were assessed for response. Disease responded to induction chemotherapy completely in 3 patients (25%) and partially in 8 patients (67%); 1 patient had a minor response (8%). Eleven patients had surgical resection; 1 refused surgery. Tumors were removed completely in 9 (82%) and incompletely in 2 (18%) of 11 patients who had been receiving radiation therapy and consolidation chemotherapy. All 12 patients are alive (100% at 7 years), with a median follow-up of 43 months, and 10 patients are disease free (73% disease-free survival at 7 years). A high correlation was seen between tumor necrosis after induction chemotherapy and Ki-67 expression (r=-0.88). CONCLUSIONS: Aggressive multimodal treatment is highly effective and may cure locally advanced, unresectable malignant thymoma.

Adult↗

PubMed1998

Autofluorescence bronchoscopy in the detection of squamous metaplasia and dysplasia in current and former smokers.

BACKGROUND: New methods are needed to detect precancerous lesions in lung tissue. We conducted a study to determine the utility of LIFE (laser-induced fluorescence emission) autofluorescence bronchoscopy for the detection of squamous metaplasia and dysplasia in current and former smokers. METHODS: In this prospective, single-center study, 53 participants underwent standard white-light bronchoscopy and 39 underwent both white-light and LIFE bronchoscopy. Bronchial biopsy specimens were obtained from all participants at six pre-determined sites using white-light bronchoscopy and from all other sites that appeared to be abnormal in participants who underwent LIFE bronchoscopy. Relationships between LIFE imaging and histologic findings were examined for 245 biopsy specimens obtained from those participants who had undergone LIFE bronchoscopy. RESULTS: LIFE imaging revealed abnormalities designated as either class II or class III in 89 (36.3%) and 16 (6.5%) of the 245 sites examined, respectively, and histopathologic examination showed dysplasia and metaplasia in eight (3.3%) and in 52 (21.2%) of the 245 specimens, respectively. Among the 105 biopsy specimens obtained from sites with abnormal LIFE imaging, only 26 (24.8%) exhibited squamous metaplasia and/or dysplasia, similar to the findings for sites with normal LIFE imaging (34 [24.3%] of 140). Comparison of individuals examined by LIFE imaging with those who underwent white-light bronchoscopy alone revealed no increase in the detection of dysplasia or metaplasia with LIFE bronchoscopy. CONCLUSION: In this population of current and former smokers, abnormalities detected by LIFE bronchoscopy did not improve the detection of squamous metaplasia or dysplasia.

Adult↗

PubMed1998

Suppression of c-Fos gene transcription with malignant transformation of human bronchial epithelial cells.

The Activator Protein-1 (AP-1) complex is a dimeric transcription factor composed of fos and jun proteins that regulates cellular growth and differentiation. We previously demonstrated a reduction in basal AP-1 transcriptional activity associated with the malignant transformation of human bronchial epithelial (HBE) cells that was, in part, a consequence of decreased c-fos expression. In this study, we investigated the mechanisms underlying the reduction in c-fos expression associated with the malignant transformation of HBE cells. c-Fos gene transcription was lower in tumorigenic HBE cells than in normal HBE cells, and the reduction in transcription involved c-fos gene promoter elements from -327 to +40. DNaseI footprinting and band shift analyses of motifs within this c-fos promoter region, including a cyclic AMP response element (CRE), serum response element (SRE), sis-inducible element (SIE), and a YY1 site, revealed that binding to these motifs was greater in tumorigenic HBE cells than in normal HBE cells. Site-directed mutagenesis of the CRE partially relieved the repression of c-fos promoter activity in tumorigenic HBE cells. Further, the activity of the Jun N-terminal Kinase (JNK)-dependent pathway, which was a positive regulator of the c-fos promoter, was greater in normal HBE cells than in tumorigenic HBE cells. These findings demonstrate a transcriptionally-mediated suppression of c-fos gene expression associated with the malignant transformation of HBE cells. The decreased activity of the c-fos promoter in tumorigenic 1170I cells appeared to involve suppression through a CRE site and reduced activation by JNK-dependent pathways.

Bronchi↗

PubMed1998

All-trans-retinoic acid inhibits Jun N-terminal kinase-dependent signaling pathways.

Retinoids, including retinol and retinoic acid derivatives, inhibit the growth of normal human bronchial epithelial (HBE) cells. The signaling pathways through which retinoids mediate this effect have not been defined. Normal HBE cell growth is stimulated by treatment with a variety of growth factors that increase mitogen-activated protein (MAP) activity. In this study, we examined MAP kinase-dependent pathways as potential targets of retinoid signaling and the role of MAP kinases in retinoid-induced c-fos gene regulation. All-trans-retinoic acid (t-RA) inhibited Jun N-terminal kinase (JNK) and, to a lesser extent, extracellular signal-regulated kinase activity in normal HBE cells. t-RA reduced c-fos mRNA and protein levels by decreasing c-fos gene transcription. The c-fos promoter was activated by co-transfection with a constitutively active JNK kinase (SEK)-1 and suppressed by a dominant negative JNK kinase kinase (MEKK)-1. Furthermore, c-fos expression was inhibited by agonists of retinoic acid receptors (RARs) or retinoid X receptors (RXRs), and suppression of c-fos promoter activity by t-RA was abrogated by treatment with antagonists of RAR-alpha or of all the RXRs. These findings provide the first evidence that t-RA inhibits JNK activity and demonstrate a potential role of JNK-dependent pathways in the suppression of c-fos expression by t-RA. Furthermore, c-fos expression was inhibited through activation of RAR- and RXR-dependent signaling pathways. In light of the growth activation induced by JNK/SEK-dependent pathways in a variety of cells, these data support further investigation into the role of JNK-dependent signaling in the growth-suppressive effects of retinoids.

Bronchi↗

PubMed1998

All-trans retinoic acid converts E2F into a transcriptional suppressor and inhibits the growth of normal human bronchial epithelial cells through a retinoic acid receptor- dependent signaling pathway.

Retinoids, including retinol and retinoic acid derivatives, maintain the normal growth and differentiation of human bronchial epithelial (HBE) cells and are under investigation as agents for lung cancer prevention. In this study, we examined the biologic effects of retinoids on normal HBE cells and the molecular mechanisms of retinoid actions. At a dose of 10(-6) M, all-trans retinoic acid (t-RA) suppressed the proliferation of normal HBE cells, which accumulated in the G0 phase. No evidence of programmed cell death was observed. The class of retinoid nuclear receptor that mediated the growth arrest was explored. Normal HBE cell growth was suppressed by a retinoid that selectively activates retinoic acid receptors but not by one that activates retinoid X receptors. The E2F transcription factor has demonstrated a role in G0 entry through transcriptional suppression of genes that induce cell cycle progression. To investigate the role of E2F in retinoid signaling, transient transfection assays were performed using reporter plasmids containing E2F-binding sites. Findings from these experiments suggested that t-RA treatment converted E2F into a transcriptional suppressor. Supporting this possibility, t-RA inhibited the expression of the E2F target genes B-myb, cyclin A, and cyclin E. Further, t-RA increased the levels of nuclear E2F-4, p107, and p130 and enhanced the binding of E2F-4 to p107, which have been associated with the conversion of E2F into a transcriptional suppressor in other cells. These findings point to retinoic acid receptor- and E2F-dependent pathways as potential mediators of retinoid-induced growth arrest in normal HBE cells and have implications for the use of retinoids in clinical trials on the prevention of lung cancer.

Apoptosis↗

PubMed1998

Should a cancer patient be resuscitated following an in-hospital cardiac arrest?

OBJECTIVE: Previous reports from general hospitals and cancer centers have identified the presence of malignancy as a poor prognostic indicator for successful cardiopulmonary resuscitation (CPR) for an in-hospital cardiac arrest. The purpose of this study was to evaluate the initial success of CPR as determined by return of spontaneous circulation (ROSC), patient survival to hospital discharge, and 1-year survival of this group as compared to previous studies in non-oncological centers. In addition, the charges incurred in caring for these patients were analyzed. MATERIALS AND METHODS: All cardiac arrests occurring between 1 January 1993 and 31 December 1994 were identified from a centralized morbidity and mortality database and reviewed retrospectively. Cardiac arrest was defined as the absence of a palpable pulse and initiation of CPR. Patients suffering pure respiratory arrest or shock without loss of pulse were excluded. Age, gender, primary site of malignancy, initial and ultimate outcome, including Zubrod's functional status (ZFS), and total hospital charges following cardiac arrest were recorded. Computerized billing records were used to tabulate total charges. RESULTS: 83 cardiac arrests occurred during the study period (42 women, 41 men). Mean age was 56.2 years. Forty-two percent of the patients had hematologic malignancies, 19% lung, 15% gastrointestinal, 5% head and neck cancers and 19% other malignancies. Sixty-six percent of the patients had ROSC. Only eight (9.6%) patients survived to hospital discharge: three died within 6 weeks under hospice care, two died within 6 months of discharge and only three (3.6%) patients survived to 1 year. Functional status follow-up of these three patients revealed two with ZFS 1 and one with ZFS 2. Total hospital charges for these 83 patients were US$ 2,959,740. CONCLUSIONS: Although ROSC after cardiac arrest in our patients was better than that reported for most series in general hospitals, their ultimate survival and hospital discharge was extremely poor.

Cardiopulmonary Resuscitation↗

PubMed1998

Feasibility of noninvasive mechanical ventilation in the treatment of acute respiratory failure in postoperative cancer patients.

PURPOSE: Patients with cancer who require mechanical ventilation have high mortality rates. Although oncological patients have multiple clinical problems, including nutritional and immunological deficiencies, added complications from mechanical ventilation by themselves may be life-threatening and may further compromise the ability of these patients to recover from an episode of acute respiratory failure (ARF). Noninvasive mechanical ventilatory support (NIMV) using positive-pressure-ventilation delivered through a mask has gained popularity for the treatment of ARF and may limit some mechanical ventilation complications. The purpose of this study was to prospectively evaluate NIMV in cancer patients with ARF. MATERIALS AND METHODS: All patients admitted to the surgical intensive care unit (SICU) at The University of Texas M.D. Anderson Cancer Center from August 1, 1994, to April 15, 1996, with hypoxemic or hypercapnic ARF were eligible for this study. NIMV was delivered with the BiPAP S/T-D (Respironics, Murrysville, PA) device. The initial settings were adjusted to achieve a tidal volume of 5 to 7 mL/kg and a SaO2 greater than 0.90. Demographic data, duration of therapy, and need for endotracheal intubation were recorded for each patient. RESULTS: Sixty patients were included in this study. There were 21 women (35%) and 39 men. The primary cancer sites of these patients were gastrointestinal (25 patients), genitourinary (15), hematological (8), lung (6), sarcoma (4), and skin (2). Fifty-three patients (88%) had hypoxemic ARF and 7 had hypercapnic ARF. The mean duration of NIMV was 1.83 days (range, 1 to 5 days) with a median of 2 days. Forty-two patients (70%) were weaned from NIMV and were spared endotracheal intubation. The remaining 18 patients deteriorated and ultimately required intubation and assisted mechanical ventilation. No complications related to the use of NIMV were seen in this study population. CONCLUSIONS: NIMV was effective in the treatment of ARF in cancer patients at our institution substantially decreasing the need for intubation. This ventilatory technique is a viable option for cancer patients with ARF.

Acute Disease↗