Intermediate Markers and Molecular Genetics of Lung Carcinogenesis

BACKGROUND: Various options are available for the local control of cancer in the breast - mastectomy, conservation therapy, and mastectomy with reconstruction. METHODS: To evaluate the benefits and drawbacks of the available management options, the authors combine their extensive experience with a review of the literature on outcomes from these approaches. RESULTS: Conservation therapy provides survival outcomes similar to those from mastectomy. Differences in local recurrence rates can be minimized by close adherence to guidelines for patient selection, operative approach, and radiation technique. CONCLUSIONS: The role of the physician in selecting a local therapy for breast cancer has changed from one of informing the patient of the treatment to assessing the presence of medical contraindications to any of the treatments, educating the patients on each treatment approach, providing access to multidisciplinary consultation, and allowing the patient to choose an appropriate treatment approach.

A prospective study of risk factors and decision making in discontinuation of dialysis

BACKGROUND

Discontinuation of dialysis is a common cause of death. We performed a prospective study to determine if a detailed description of patients could be used to identify those at risk for discontinuing dialysis.

METHODS

Two hundred thirty-five dialysis patients were studied for 3 1/2 years. Using questionnaires, medical chart analyses, and interviews, 300 sociodemographic, quality-of-life, medical and dialysis variables were prospectively obtained. The association of these variables with death from discontinuation of dialysis was studied in univariate and multivariate analyses.

RESULTS

Seventy-six patients (32%) died during the follow-up period, 31 (41%) of cardiovascular problems, 13 (17%) of discontinuation of dialysis, and 32(42%) of other causes. Patients who discontinued dialysis were older (mean age, 66 vs 54 years), were more likely to be divorced or widowed (46% vs 16%), were more likely to live in nursing homes (31% vs 6%), spent less time outdoors (23% vs 53%), had twice as much comorbidity as other patients (major comorbidity score, 1.2 vs 0.6), had the same psychological quality-of-life score (60 vs 62) but a lower score on the Karnovsky Scale, and a higher physical discomfort index. In multivariate analysis, comorbidity, widowed or divorced status, and severe pain were independent predictors of discontinuation of dialysis, but no reliable predictive model could be created. A detailed analysis of the final event indicated that a relentless succession of problems often led nursing home patients to discontinue dialysis. These problems are common to all dialysis patients, especially those who have no one to support them in their suffering.

CONCLUSIONS

Discontinuation of dialysis is common, and can been seen as a failure of and a relief from long-term dialysis. We believe mortality caused by discontinuation of dialysis could be decreased by better psychological support and improved management of ischemic problems and pain. We found no predictable model for such patients, but many successive acute problems in widowed and divorced patients seem to trigger the decision.

Idiopathic hyperammonemia: a frequently lethal complication of bone marrow transplantation

Idiopathic hyperammonemia (IHA) has been described as a rare complication of intensive chemotherapy, but there is little data regarding its occurrence after bone marrow transplantation (BMT). IHA is defined as elevated plasma ammonia concentrations (> 200 mumol/l) in the absence of significant liver function abnormality. From a 21 year BMT database of 2358 patients, we have identified 12 patients (0.5%) with IHA, ages 19 to 46 years. Diagnoses included ALL (n = 2), AML (n = 4), CLL (n = 1), CML (n = 3) and aplastic anemia (n = 2). Eight received marrow from a matched sibling donor, three from an unrelated donor and one autologous marrow. IHA occurred between 14 and 106 days after transplant (median, 25 days). Most frequently patients presented with symptoms of a metabolic encephalopathy, with lethargy and confusion evolving into unresponsiveness, metabolic coma and in eight cases, seizures. At diagnosis of IHA, liver functions were normal or only modestly abnormal. Ten of the 12 patients died 1 to 9 days (median 3.5 days) after diagnosis of IHA despite treatment with combinations of dialysis and ammonia-trapping therapy. While IHA is a rare complication of BMT, it is associated with a high mortality. Early recognition of the syndrome by measurement of plasma ammonia concentrations in patients with neurological symptoms may improve outcome.

Effect of 1-beta-D-arabinofuranosylcytosine on apoptosis and differentiation in human monocytic leukemia cells (U937) expressing a c-Jun dominant-negative mutant protein (TAM67)

The proto-oncogene c-jun encodes a component of the AP-1 transcription-activating complex and has been implicated in the regulation of diverse cellular processes, including cell proliferation, differentiation, transformation, and most recently, apoptosis. We have used a U937 monocytic leukemia cell line stably expressing a c-jun dominant-negative, transactivation-domain deletion mutant (TAM67) to assess the role of c-jun in apoptotic events induced by exposure to the antimetabolite 1-beta-D-arabinofuranosylcytosine (ara-C). Mutant cells produce a truncated M(r) 29,000 protein that interferes with the function of normal c-Jun (and c-Fos) proteins through a quenching mechanism. Parental U937, cells expressing TAM67, and cells carrying only the empty vector (pMM) were exposed to ara-C for 6 h, and apoptosis was monitored by cell morphology as well as qualitative and quantitative assays of DNA damage. No differences in apoptosis could be detected between the three cell lines at any of the ara-C concentrations evaluated. In addition, ara-C concentrations > or = 1.0 x 10(-6) M were equally inhibitory to the clonogenic growth of U937 and TAM67-expressing cells. In contrast, lower concentrations of ara-C (i.e., < 5.0 x 10(-7) M) were significantly less inhibitory to mutant U937 cell colony formation than to their parental counterparts. The reduced sensitivity of TAM67-expressing cells to low concentrations of ara-C could not be attributed to biochemical or cytokinetic factors, since the two cell lines were indistinguishable with respect to 1-beta-D-arabinofuranosylcytosine 5'-triphosphate (ara-CTP) formation, ara-CTP:dCTP ratios, and S-phase fraction. However, a significantly lower percentage of TAM67-expressing cells exposed to submicromolar concentrations of ara-C exhibited features associated with a differentiated monocytoid phenotype (i.e., increased plastic adherence and CD11b expression) compared to their parental counterparts. Lower concentrations of ara-C were also significantly less effective in decreasing the percentage of S-phase cells and in down-regulating c-myc mRNA levels in the mutant line, events associated with induction of leukemic cell differentiation. Finally, ara-C-induced up-regulation of c-jun message and protein was markedly attenuated in TAM67-expressing cells, findings consistent with a c-jun dominant-negative model. Collectively, these findings suggest that dysregulation of c-jun in U937 cells antagonizes low-dose ara-C-mediated cellular maturation but does not prevent higher concentration of this agent from triggering apoptosis. They also raise the possibility that separate aspects of the antiproliferative actions of ara-C may be differentially regulated by c-jun.

Role of c-jun in human myeloid leukemia cell apoptosis induced by pharmacological inhibitors of protein kinase C

Recent study results suggest that protein kinase C [PKC (EC 3.1.4.3)] -dependent up-regulation of c-jun may be involved in leukemic cell programmed cell death, or apoptosis, occurring in response to various chemotherapeutic agents. The current study was undertaken to further evaluate the contribution of c-jun in apoptosis with the use of two highly specific pharmacological inhibitors of PKC (calphostin C and chelerythrine). To address this issue, two human leukemic cell lines, HL-60 and U937, and a U937 subline stably expressing a dominant negative c-jun mutant (TAM67) were exposed to calphostin C and chelerythrine, and c-jun expression was monitored at both the mRNA and protein levels. Both PKC inhibitors induced the classic morphological features of apoptosis as well as internucleosomal DNA degradation in a concentration- and schedule-dependent manner. Concomitant with these changes, unequivocal increases were observed in c-jun mRNA (U937 and HL-60) and protein (U937). In contrast, up-regulation of c-jun mRNA and protein in TAM67-expressing cells exposed to both PKC inhibitors was markedly attenuated relative to effects observed in parental U937 cells. Importantly, despite impaired up-regulation of c-jun at both the message and protein levels, TAM67-expressing cells were equally susceptible to PKC inhibitor-induced apoptosis as parental and empty vector U937 cells. Collectively, these findings raise the possibility that c-jun up-regulation in human myeloid leukemia cells undergoing PKC inhibitor-associated apoptosis represents a response to, rather than a cause of, apoptotic events. They further suggest that this phenomenon involves pathways that do not require PKC activation.

Requirement for ceramide-initiated SAPK/JNK signalling in stress-induced apoptosis

The induction of programmed cell death, or apoptosis, involves activation of a signalling system, many elements of which remain unknown. The sphingomyelin pathway, initiated by hydrolysis of the phospholipid sphingomyelin in the cell membrane to generate the second messenger ceramide, is thought to mediate apoptosis in response to tumour-necrosis factor (TNF)-alpha, to Fas ligand and to X-rays. It is not known whether it plays a role in the stimulation of other forms of stress-induced apoptosis. Given that environmental stresses also stimulate a stress-activated protein kinase (SAPK/JNK), the sphingomyelin and SAPK/JNK signalling systems may be coordinated in induction of apoptosis. Here we report that ceramide initiates apoptosis through the SAPK cascade and provide evidence for a signalling mechanism that integrates cytokine- and stress-activated apoptosis.

Altered cJUN expression: an early event in human lung carcinogenesis

Although the c-jun oncogene is an integral part of the AP-1 transcriptional complex implicated in the process of tumor promotion, its role in the pathogenesis of human tumors is unknown. We analyzed the expression and function of cJun in 110 non-small cell lung cancer (NSCLC) primary and metastatic tumors, histologically atypical areas from the surrounding lung, and 10 NSCLC cell lines to examine the role of cJun in lung carcinogenesis. cJun was expressed in primary and metastatic lung tumors in 31% of cases, with no association with survival. Whereas normal conducting airway and alveolar epithelial in general did not express cJun by immunohistochemistry, histologically atypical areas were frequently positive for cJun, regardless of the status of the corresponding tumor. Multiple members of the jun and fos gene families were frequently expressed at the mRNA level in vitro, with detectable functional activity (as defined by AP-1-specific DNA binding and/or transactivation of an AP-1-driven reporter construct) present in all 10 NSCLC cell lines examined. Although tumor-promoting phorbol esters had little effect on c-jun expression, serum stimulation generally resulted in significant c-jun induction in NSCLC cell lines. These data show that cJun expression is altered early during human lung carcinogenesis and that cJun may function as a mediator of growth factor signals in NSCLC.

Botulinum neurotoxin type G proteolyses the Ala81-Ala82 bond of rat synaptobrevin 2

Tetanus toxin and the botulinum neurotoxins types A to F inhibit neurotransmitter release from presynaptic nerve endings by selectively proteolysing the synaptic proteins synaptobrevin, syntaxin, or SNAP-25. Here, we show that botulinum toxin type G cleaves rat synaptobrevin 2 between Ala81 and Ala82, a peptide bond that differs from those attacked by tetanus toxin and the botulinal toxins types B, D, and F. Synaptobrevin isoforms carrying a Gly in the P1 position are poor substrates. Analyses of N-terminal deletion mutants of rat synaptobrevin 2 showed that a substrate starting at Leu54 is cleaved efficiently, whereas substrates beginning at Leu60 or Phe77 are cleaved partially or not at all, respectively.

Constitutive cJun expression induces partial macrophage differentiation in U-937 cells

Previous studies have shown that phorbol ester induced macrophage differentiation in the leukemic cell line U-937 is tightly linked to the expression of the c-jun protooncogene and the generation of AP-1 transcriptional activity. We expressed the c-jun protooncogene in U-937 cells to examine the role of c-jun in the differentiation of these cells. AP-1 DNA binding activity and the expression of AP-1 controlled downstream genes were increased in all clones expressing exogenous cJun. More importantly, these transfectants showed evidence of differentiation as measured by the acquisition of phagocytic capacity, although they did not develop morphological changes associated with differentiation such as adherence. Furthermore, they became committed to terminal differentiation after significantly shorter exposures to phorbol esters than did control cell lines. These data show that cJun expression induces partial differentiation along the macrophage pathway in U-937 cells.

Suppression of oncogene-induced transformation by a deletion mutant of c-jun

Jun and Fos proteins are DNA-binding proteins that are involved in the control of gene expression through transcriptional regulation. We have made a deletion mutant of the c-jun gene that lacks amino acids 3-122 of c-jun, and thus is missing the major transactivation domain of c-jun, but retains the DNA-binding and leucine zipper domains. Unlike c-Jun, the mutant protein is unable to stimulate the transcription of an AP-1 responsive gene, and unlike c-jun this mutant gene is unable to transform rat embryo cells in cooperation with an activated ras gene. However, this mutant protein blocks in vitro DNA binding of Jun-Jun homodimers and Jun-Fos heterodimers, transcriptional activation induced by c-jun or c-fos and transformation of rat embryo cells induced by an activated ras gene and a deregulated c-jun or c-fos gene. In addition, transformation of rat embryo cells induced by an activated ras gene in the presence of the tumor promoter 12-O-tetradecanoyl phorbol 13-acetate (TPA) or by ras plus SV40 large T antigen is also inhibited by this dominant-negative mutant, suggesting that a member of the jun or fos family is involved in the pathways leading to transformation in these systems as well. The possible molecular mechanisms by which this dominant-negative mutant of c-jun blocks the functions of wild-type jun and fos family members are discussed.

Epidemiology, prognostic factors, and prevention of lung cancer

Lung cancer continues to be a leading cause of preventable death, with an estimated 123,000 of the 143,000 lung cancer deaths in the United States in 1991 directly attributable to tobacco smoking. Given that mortality from this disease has not changed appreciably in the past two decades and despite continuing advances in cancer treatment, a new emphasis is being placed on prevention and early detection research through the identification of high-risk individuals and the definition of useful biomarkers. This review summarizes the status of these efforts over the past year.

Prolyl Endopeptidase and Dipeptidyl Peptidase IV are Distantly Related Members of the Same Family of Serine Proteases

Prolyl endopeptidase and dipeptidyl peptidase IV are serine proteases which cleave the peptide bonds at the carboxy group of proline residues. They do not show amino acid sequence homology with the known serine enzymes, but a possible relationship between them has not yet been examined. We have compared the amino acid sequences, and this revealed a distant evolutionary relationship between the two enzymes. Conserved segments were found mainly in the C-terminal region which also contained the catalytic residues. It is concluded that the C-terminal region is a protease domain which is attached to some noncatalytic structures.

The role of jun and fos gene family members in 12-O-tetradecanoylphorbol-13-acetate induced hemopoietic differentiation

Terminal differentiation of the leukemic cell lines U-937 and HL-60 by 12-O-tetradecanoylphorbol-13-acetate is accompanied by marked changes in gene expression. In this study, we demonstrate that the expression of jun and fos gene family members is induced with variable kinetics during 12-O-tetradecanoylphorbol-13-acetate induced differentiation, with c-jun expression best paralleling differentiation. The generation of AP-1 complexes, as measured by DNA binding activity, closely parallels morphological differentiation. Furthermore, the ability of these complexes to regulate gene expression is demonstrated by increased transcription from an AP-1 driven reporter construct and marked increases in the expression of endogenous AP-1 regulated genes. Differentiation assays using water soluble phorbol esters reveal that differentiation becomes irreversible soon after AP-1 appears. This tight correlation between c-jun expression, the generation of AP-1 activity, and differentiation suggests a critical role for this gene and transcriptional complex during this process.

The distribution of bromine content of dibromodulcitol in the central nervous system of patients with malignant gliomas

The bromine content of human gliomas and white matter was determined by neutron activation analysis (NAA) following p.o. administration of a single dose of 400-500 mg/m2 dibromodulcitol (DBD). In another group of patients with brain gliomas, the bromine content was measured subsequent to application of a single dose of 334 mg/m2 of sodium bromide (equivalent dose regarding the bromine content of DBD). The bromine content of these two groups was compared to the values found in a third control group of untreated patients. The amount of bromine after DBD application was three to four times higher than in the untreated samples and the average accumulation ratio of 1.8 +/- 0.4 proved to be nearly identical both in tumour and white matter. The bromine values after NaBr treatment showed a different pattern of distribution. The accumulation was higher in the tumour tissue than in the normal white matter. These findings demonstrate that the pharmacokinetic properties of DBD- and NaBr-derived bromine are different, suggesting that the increase of bromine after DBD administration could be due to covalently bound bromine in DBD.

The influence of various amino acids on the extrahepatic bile ducts in newborn mice--an experimental study

Excess proline in adult animals is associated with extrahepatic biliary hyperplasia. Possible therapeutic application of this amino acid in biliary atresia was postulated. In order to test whether excess proline had an influence on the development of the extrahepatic bile ducts, pregnant mice were injected daily with various amino acids. One day and 1 week after delivery, the extrahepatic bile ducts of the newborn mice were studied and the number of epithelial cells per cross section was determined. Neither proline nor any other amino acid had an influence on the proliferation of extrahepatic bile ducts.

Immunocytochemical analysis of estrogen receptors as a predictor of prognosis in breast cancer patients: comparison with quantitative biochemical methods

Biochemical quantitation of estrogen receptors has been used to predict prognosis in breast cancer. Immunocytochemical analysis of estrogen receptors correlates with biochemical analysis but has very few follow-up studies in the literature to validate it as a prognostic indicator. 257 patients were followed for up to 10 years (median, 6.2 years) after primary surgical treatment. Estrogen receptor analysis using both biochemical and immunocytochemical techniques was performed on their tumor specimens. Patients with positive estrogen receptor values had longer survival than patients with negative values. This was demonstrated by both methods in the first 5 years of follow-up but only by immunochemistry after 5 years. The relationship between estrogen receptor status and disease-free interval was less strong than with survival. This study demonstrates that immunocytochemical estrogen receptor analysis was of prognostic significance.

Membranous nephropathy accompanied by angiolymphoid hyperplasia of the skin

A 24-year-old female developed a painless swelling adjacent to the left ear. This was shown to be eosinophilic angiolymphoid hyperplasia (ALH). Three months later she developed a nephrotic syndrome. Renal biopsy revealed membranous nephropathy. This is the first non-Japanese case of dermal eosinophilic ALH and nephrotic syndrome; steroid treatment followed by surgical removal of the tumour resulted in complete remission in the renal lesion.

Use of a monoclonal anti-estrogen receptor antibody in the immunohistochemical evaluation of human tumors

A monoclonal antibody to human estrogen receptor protein (H222 Sp gamma), amplified via immunoperoxidase techniques, was used in the analysis of estrogen receptor in 452 breast carcinomas, 100 endometrial carcinomas, and 15 melanomas. Immunohistochemical evaluation incorporated both intensity and distribution of staining (HSCORE). Quantitative estrogen receptor content was determined by dextran-coated charcoal analysis and sucrose density gradient analysis. In all cases H222 Sp gamma localized in the nucleus of target cells. A semiquantitative correlation existed between HSCORE and biochemical assays for breast and endometrial tissues. The sensitivities and specificities for HSCORE as compared to the biochemical assays ranged from 80 to 95% and from 74 to 94%, respectively. HSCORE correlated with tumor grade for breast and endometrial carcinoma. Immunohistochemical evaluation showed no specific staining in melanomas. The data suggest that immunohistochemical receptor localization provides information complementary to standard biochemical assays in the tissues studied.