Molecular mechanisms of polymyxin B-membrane interactions: direct correlation between surface charge density and self-promoted transport

We have studied the interaction of the polycationic peptide antibiotic polymyxin B (PMB) with asymmetric planar bilayer membranes via electrical measurements. The bilayers were of different compositions, including those of the lipid matrices of the outer membranes of various species of Gram-negative bacteria. One leaflet, representing the bacterial inner leaflet, consisted of a phospholipid mixture (PL; phosphatidylethanolamine, -glycerol, and diphosphatidylglycerol in a molar ratio of 81:17:2). The other (outer) leaflet consisted either of lipopolysaccharide (LPS) from deep rough mutants of PMB-sensitive (Escherichia coli F515) or -resistant strains (Proteus mirabilis R45), glycosphingolipid (GSL-1) from Sphingomonas paucimobilis IAM 12576, or phospholipids (phosphatidylglycerol, diphytanoyl-phosphatidylcholine). In all membrane systems, the addition of PMB to the outer leaflet led to the induction of current fluctuations due to transient membrane lesions. The minimal PMB concentration required for the induction of the lesions and their size correlated with the charge of the lipid molecules. In the membrane system resembling the lipid matrix of a PMB-sensitive strain (F515 LPS/PL), the diameters of the lesions were large enough (d = 2.4 nm +/- 8%) to allow PMB molecules to permeate (self-promoted transport), but in all other systems they were too small. A comparison of these phenomena with membrane effects induced by detergents (dodecyltriphenylphosphonium bromide, dodecyltrimethylammonium bromide, sodiumdodecylsulfate) revealed a detergent-like mechanism of the PMB-membrane interaction.

The number of lymph node metastases influences survival in esophageal cancer

BACKGROUND AND OBJECTIVES

Lymph node involvement adversely affects the survival of patients with esophageal cancer. We retrospectively investigated whether the number of involved lymph nodes and the degree of lymph node dissection affect survival.

PATIENTS AND METHODS

Eighty-eight patients underwent surgical resection and reconstruction for T -T3 thoracic esophageal squamous cell carcinoma. Patients were classified into three groups: group 1, 32 patients without lymph node involvement; group 2, 26 patients with 1 to 3 positive nodes; and group 3, 30 patients with > or = 4 involved lymph nodes.

RESULTS

The 3-year and 5-year survival rates were 34.8% and 30.0% in group 1, 30.0% and 22.7% in group 2, and 14.8% and 0% in group 3, respectively. The mean survival time (MST) X +/- SD of the patients in group 3 (453.06+/-74.5 days) was significantly shorter than in group 1 (450.1+/-450.5, P = 0.0005) and group 2 (937.3+/-1317.9, P = 0.0295). For patients in groups 1 and 2, the MST for three-field lymph node dissection (1136.9+/-1476.4 days) was longer than for two-field lymph node dissection (1007.4+/-1476.4 days, P = 0.0355). However, in group 3, there was no survival advantage to three-field lymph node dissection.

CONCLUSION

We conclude that the survival in patients with thoracic esophageal cancer involving four or more nodes, is poorer than in patients with lesser involvement. Three-field lymph node dissection does contribute to prolonged survival in patients with node-negative disease or fewer than four positive nodes.

Detection of chromogranin A mRNA in small cell lung carcinoma using a new, highly sensitive in situ hybridization method with a non-radioisotope oligonucleotide probe

BACKGROUND

Immunoreactivity for chromogranin A (Cg A) is associated with the presence of neurosecretory granules in tumor cells, but immunohistochemical staining for Cg A may be absent in small cell lung carcinoma (SCLC), which has only a few secretory granules. Localization of Cg A mRNA is a useful indicator of the site of synthesis of a particular protein and possibly the rate of synthesis, and it is not dependent on posttranslation events within the cells. However, it is difficult to detect the low levels of mRNA copies using the standard non-radioisotope (RI) oligonucleotide probe.

METHODS

The authors analyzed Cg A mRNA in 20 cases of SCLC in formalin fixed, paraffin embedded tissue using a new, highly sensitive in situ hybridization method that was developed from the maximized immunohistochemistry (ImmunoMax) method. They also investigated Cg A mRNA in nonsmall cell lung carcinoma (NSCLC), including ten cases each of adenocarcinoma and squamous cell carcinoma of the lung.

RESULTS

All examined SCLC tissues showed a positive reaction for Cg mRNA. No NSCLC specimens showed any positive reaction for Cg A mRNA.

CONCLUSIONS

The detection of Cg A mRNA using the new, highly sensitive in situ hybridization method with a non-RI oligonucleotide probe can be used to characterize neuroendocrine differentiation of lung tumors even when the Cg A protein is not detected by immunohistochemistry. The authors believe this is a first step toward better diagnosis and treatment for patients with SCLC.

[Characteristics of home parenteral nutrition and effectiveness of 3 way valved PICC in regional medical care]

Home medical care is becoming a greater matter of concern along with the increasing population of elderly persons. The various difficulties in home care are also found in regional care, and it could be said that in Japan regional care serves as an "advanced model" for home medical care. Ohya Town is located in the mountains of northern Hyogo Prefecture. It has a population of about 5,000 of which 32% is elderly people. There is no railroad, and it takes around 30 minutes to travel to the central hospital from the area. The three town clinics are in contact with each other and with the central hospital concerning medical information. The characteristics of Home Parenteral Nutrition in this underpopulated district are discussed and reported in reference mainly to cases in which the 3 way valved peripherally inserted central venous catheter (Groshong Catheter) is used, in comparison with HPN cases in the city university hospital.

Ribozyme-based gene cleavage approach to chronic arthritis associated with human T cell leukemia virus type I: induction of apoptosis in synoviocytes by ablation of HTLV-I tax protein

OBJECTIVE

To develop gene therapy for patients with human T cell leukemia virus type I (HTLV-I)-associated arthropathy (HAAP), we investigated the effects of ribozyme-mediated cleavage of HTLV-I tax/rex messenger RNA (mRNA) on synovial overgrowth.

METHODS

We introduced 2 hammerhead ribozymes targeted against HTLV-I tax/rex mRNA into synovial cells obtained from patients with HAAP and from patients with HTLV-I-negative rheumatoid arthritis (RA) and examined the ribozyme-mediated ablation of Tax expression. Using standard methods, we also determined the cells' ability to stop proliferating and to undergo apoptosis.

RESULTS

The ribozymes successfully cleaved tax/rex mRNA in HAAP patient synoviocytes. Both tax mRNA expression and Tax protein synthesis were inhibited significantly, resulting in inhibition of synovial cell growth and induction of apoptosis. In contrast, synovial cells from RA patients were not affected.

CONCLUSION

In vitro results suggest that ribozyme-mediated gene therapy can inhibit the growth of HTLV-I-infected synovial cells, which is maintained by Tax protein, in HTLV-I-related diseases including HAAP.

Effects of heat fixation on tissue structure, immunostaining and in situ RT-PCR

The effects of PBS heat fixation on tissue structure, immunostaining, and in situ RT-PCR were investigated using excised mucosal tissues from both humans and various animals. It was found that basal cells were stretched to two to three times their normal length at 60 degrees C, and 4 to 5 times at 90 degrees C, resulting in detachment of the epithelium and basal cells from subjacent connective tissue. Tonofibrils disappeared completely and became an electron dense amorphous mass at 60 degrees C. Both nuclear and cytoplasmic membranes also disappeared as did intracytoplasmic organelles. Electron dense amorphous-material occupied the entire nucleus with fixation at 90 degrees C. Collagen fibrils appeared swollen at 60 degrees C and either disappeared completely or became fragmented undergoing transition to an electron dense amorphous conglomerates at 90 degrees C. Immunostaining of cytokines disappeared at 60 degrees C, and that of vimentin at 90 degrees C. However, cytokeratin and human leukocyte common antigen (CD 45RB) reactivity remained intact at both temperatures. IL-6 mRNA could be localized by in situ RT-PCR even after thermal fixation. Results suggest that a proper combination of immunohistochemistry and in situ RT-PCR will enable investigators to localize proteins in addition to DNA or RNA within oral tissue sections. This capability should prove helpful in applied histopathologic diagnostic techniques.

Involvement of the nervous system in the control of glucose uptake in contracting hindlimb muscle in the rat

To probe into the possibility of neural control of glucose uptake in contracting peripheral skeletal muscle, rats were divided into two groups: one group is the "normal" (N) group in which the nervous system is intact, and the other is the "denervation" (D) group in which all nerves innervating the hindlimb were cut. The immediate changes in blood glucose (BG) and plasma insulin (PI) levels were measured at the commencement and termination of hindlimb muscle contraction induced with electrical stimulation of the sciatic nerve (distal part in D group). BG in N group temporarily but significantly decreased (p < 0.01) immediately after starting the stimulation, while BG in D group remained unchanged. And the difference between the changes in BG observed in 2 groups was significant (p < 0.03). PI did not change in either group during the sample period. On the other hand, PI temporarily but significantly decreased (p < 0.03) immediately after terminating the stimulation in both groups. The results suggest that the nervous system has some role in controlling glucose uptake in contracting peripheral muscle, at least in the early stage of contraction, that some feedback loop, including the central nervous system, is considered essential for the control, and that some local mechanism promotes an increase in insulin binding to receptors on muscle cells immediately after terminating the contraction.

New quinolones, ofloxacin and levofloxacin, inhibit telomerase activity in transitional cell carcinoma cell lines

It has been demonstrated that some quinolone antibiotics inhibit cell proliferation in vitro. This study showed that ofloxacin and levofloxacin, two well-known new quinolones, had an inhibitory effect on the proliferation of transitional cell carcinoma cell lines at high concentrations (>200 microg/ml). At relatively low concentrations (10-100 microg/ml), however, there was no apparent antiproliferative effect. Despite this, decreased absorbance in the MTT assay was observed at low concentrations and telomerase activity was significantly decreased. These results suggest that the antiproliferative effect of both ofloxacin and levofloxacin may be related to impairment of telomerase activity by some unknown mechanism.

A novel component different from endotoxin extracted from Prevotella intermedia ATCC 25611 activates lymphoid cells from C3H/HeJ mice and gingival fibroblasts from humans

A novel immunobiologically active fraction was prepared from a phenol-water extract of Prevotella intermedia ATCC 25611 by Sephadex G-100 column chromatography. The fraction consisted mainly of carbohydrate and protein and was devoid of fatty acid. The fraction showed high-molecular-weight bands (10,000 to 12,000) on deoxycholate polyacrylamide gel electrophoresis (DOC-PAGE) and was scarcely active in a Limulus test. We designated the fraction Prevotella glycoprotein (PGP). The PGP fraction showed strong mitogenicity on splenocytes and cytokine-inducing activities on peritoneal macrophages from both C3H/HeJ and C3H/HeN mice, and it stimulated human gingival fibroblasts to produce cytokines. The activities of the PGP fraction were resistant to heat inactivation (100 degrees C for 1 h) and protease treatments and were scarcely inhibited by polymyxin B. In contrast, the purified lipopolysaccharide fraction (LPS-PCP) extracted from the same bacterium with a phenol-chloroform-petroleum ether mixture, which showed strong Limulus activity and a single low-molecular-weight band (approximately 3,000) on DOC-PAGE, lacked the activities on splenocytes and macrophages from C3H/HeJ mice and human gingival fibroblasts. The activities of the LPS-PCP fraction on cells from C3H/HeN mice were completely inhibited by polymyxin B. The LPS extracted from the same bacterium with hot phenol-water (LPS-PW) exhibited the properties of both the PGP fraction and the LPS-PCP fraction. These findings suggest that the unique bioactivities of the LPS-PW fraction of oral black-pigmented bacteria reported to date, which differed from those of the classical endotoxin, were derived from the PGP fraction and not from the LPS itself.

Primary tracheal fibrosarcoma in a child: a case of tracheal resection under ECMO support

We report a case of severe airway obstruction due to endotracheal fibrosarcoma in a 3-year-old boy. Successful tracheal resection and reconstruction was performed under extracorporeal membrane oxygenation support. A solid, elastic hard tumor with a smooth surface was attached by a tiny stalk structure to the membranous part of the lower trachea. Histological findings of the tumor were consistent with infantile fibrosarcoma, showing proliferation of spindle cells forming interlacing patterns.

Free radical-mediated tissue injury in acute lung allograft rejection and the effect of superoxide dismutase

BACKGROUND

The role of monocytes and neutrophils is crucial during acute allograft rejection. They have the capacity to generate toxic reactive oxygen intermediates in response to specific agonists that may act as tissue destructive molecules. We examined the possibility of reactive intermediate-mediated tissue injury in acute lung allograft rejection, as well as the effect of superoxide dismutase.

METHODS

Allogenic (Brown Norway to F344) or syngenic (F344 to F344) rat left-lung transplantation was performed. Generation of reactive oxygen intermediates in peripheral blood was evaluated by the method of luminol-dependent chemiluminescence. Cell membrane phospholipid peroxidation in the graft was measured as malondialdehyde concentration. The third group of animals having allografts received bovine erythrocyte superoxide dismutase (5,000 U/kg intravenously every 12 hours after transplantation).

RESULTS

Relative chemiluminescence response in the allograft recipient to normal F344 was elevated on postoperative day 1 (257%), then decreased slightly on day 3 (156%) and was elevated again on day 7 (560%) as the process of rejection progressed. Allograft tissue malondialdehyde levels (248.37 +/- 112.35 nM/whole lung, n = 6; p < 0.05 by Student's t test) were higher than isograft levels (139.29 +/- 35.93 nM/whole lung, n = 6) on day 7. Superoxide dismutase treatment significantly ameliorated the histologic degree of rejection on day 7.

CONCLUSIONS

These results demonstrate the tissue destructive activity of reactive oxygen intermediates during lung allograft rejection. To scavenge free radicals may be a useful therapeutic modality in the management of acute lung allograft rejection.

Calcium release from intracellular stores evoked by extracellular ATP in a Xenopus renal epithelial cell line

1. The signal transduction mechanism mediating extracellular adenosine 5'-triphosphate (ATP)-induced calcium release in a renal epithelial cell line (A6) was investigated using the whole-cell voltage-clamp technique and fura-2 fluorescence measurement. 2. ATP (10 microM) activated calcium-dependent non-selective cation channels in cells held under voltage clamp. 3. Guanosine 5'-O-(2-thiodiphosphate) (GDP beta S; 0.1-1.0 mM) in the pipette inhibited the ATP-activated calcium-dependent currents. With guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S; 0.1-1.0 mM) in the pipette, the currents were spontaneously elicited without application of ATP. Pretreatment with pertussis toxin (PTX) affected neither the ATP-activated currents nor the increase in intracellular free calcium concentration ([Ca2+]i) evoked by ATP. 4. Intracellular application of neomycin or heparin inhibited the ATP-activated currents. Inositol 1,4,5-trisphosphate (IP3; 0.1-100 microM) in the internal solution produced currents similar to those due to ATP activation. 5. These results suggest that a PTX-insensitive guanosine 5'-triphosphate (GTP)-binding regulatory protein (G. protein) is involved in extracellular. ATP-induced phosphoinositide turnover and subsequent calcium release from IP3-sensitive stores, which subsequently activates the calcium-dependent channels in A6 cells.

Sapecin B, a novel fly toxin, blocks macroscopic K+ currents in the GH3 rat pituitary cell line

Sapecin B is structurally homologous to charybdotoxin (CTX), which is found in scorpion venom. This study investigated the effects of sapecin B on the Ca(2+)-activated K+ currents [IK(Ca)] and the rapidly inactivating K+ currents in clonal rat GH3 pituitary cells with whole cell voltage-clamp methods. Sapecin B (20 nM) reversibly blocked the CTX-sensitive Ix(Ca) (the BK current) in a dose-dependent manner, with a half-maximal inhibitory concentration of approximately 0.9 nM, comparable to that of 0.08-0.4 nM for CTX. The Ca2+ currents in GH3 cells, however, were not affected by sapecin B (40 nM), indicating that the blockade of IK(Ca) by sapecin B is not a secondary effect of Ca2+ current inhibition. The effect of sapecin B on IK(Ca) resembled that of CTX, as expected from the structural similarities shared by CTX and sapecin B. We also found that sapecin B largely inhibited the 4-aminopyridine-sensitive, rapidly inactivating K+ currents in a dose-dependent manner, with a half-maximal inhibitory concentration of approximately 40 nM, whereas CTX had little effect on this current in GH3 cells. Sapecin B may thus provide a useful tool, complementary to CTX, for probing the functional role of molecular domains in the BK channels and the structural similarities common to the BK and the rapidly inactivating A-type K+ channels.

[Serum transferrin receptor level as an index of the response to erythropoietin therapy for anemia in pre-dialysis patients with chronic renal failure]

In order to reveal whether serum transferrin receptor (sTfR) can serve as an index in erythropoiesis during recombinant human erythropoietin (rHuEpo) therapy for anemia in pre-dialysis patients with chronic renal failure, we analyzed hematopoietic parameters and sTfR levels in 26 patients who were newly administered rHuEpo. sTfR was determined as sTfR transferrin complex (TRC) using the enzyme linked immunosolvent assay (ELISA) and the latex agglutination nephelometric immunoassay (LA). The therapeutic effect of rHuEpo was expressed as the change in the Ht from the start of treatment to 8 weeks later. (delta Ht). Ht, RBC and Hb levels were significantly increased at 4 and 8 weeks after initiating rHuEpo treatment. Furthermore, sTfR levels were significantly increased at 2 and 4 weeks after the start of rHuEpo treatment. Absolute changes in the sTfR level (sTfR before - sTfR after) and rates of change (absolute change/sTfR before x 100) at, 2, 4 weeks after the start of rHuEpo treatment showed a significant positive correlation with delta Ht. These results indicate that sTfR is a useful marker as an index of therapeutic effect of rHuEpo for anemia in pre-dialysis patients with chronic renal failure.

[Complications of thoracoscopic surgery for spontaneous pneumothorax]

We reviewed the cases of 122 patients with primary spontaneous pneumothorax who underwent thoracoscopic surgery at our institution between 1992 and 1995. In 9 cases, thoracotomy became necessary because of severe adhesions (3 cases), large foci (3 cases), and unrecognized foci (3 cases). Complications occurred in 17 cases: collapse in 1 patient after removal of the thoracic drain, persistent air leakage (> 7 days) in 2 patients, and recurrent pneumothorax in 14 patients. There were no significant differences between the recurrent and non-recurrent cases in age, sex location of bullae, past history of pneumothorax, operating time, intraoperative blood loss, or duration of chest tube drainage after surgery. The interval between onset and consult was significantly longer in recurrent cases than in non-recurrent cases, and the number of patients who required chest tube drainage before surgery was significantly higher in recurrent cases. Reoperation was performed in 9 cases. Bullaes that were not detected during the first surgery were found in the 7 of these cases. The recurrent cases in our study were regarded as resulting from a lack of surgical skill that may improved with increasing surgical experience. The Brinkman index was significantly higher in recurrent cases. Smoking and air-leakage before surgery may be risk factors for recurrence following thoracoscopic surgery for spontaneous pneumothorax.

Video-assisted thoracoscopic lobectomy for treating lung cancer

Our objective was to evaluate the usefulness and safety of video-assisted thoracoscopic surgery (VATS) for performing pulmonary lobectomy in 11 patients with clinical NO stage I primary non-small-cell lung cancer compared with 11 patients who underwent a conventional thoracotomy. Treatment was switched to conventional thoracotomy in three VATS patients because of the involvement of interlobar nodes or incomplete lobar fissure. None of the eight VATS patients died or experienced serious complications during 12 months of follow-up. There were no significant differences in the intraoperative blood loss, duration of operation, or duration of chest tube drainage between the VATS group and the standard lobectomy group. We conclude that although VATS lobectomy appears to be safe for use in managing patients with primary lung cancer, it does not seem to offer any advantages over standard lobectomy.

Demonstration of the presence of alpha-1,6-branched side chains in the mannan of Candida stellatoidea

A mild acetolysis of the mannans of Candida stellatoidea was performed after acetylation to yielded an alpha-1,6-branched mannohexaose, the presence of which had been predicted from the appearance of a specific H1-H2-correlated cross-peak in two-dimensional homonuclear Hartmann-Hahn spectroscopy. In this study, we found that the de-O-acetylation of a 4-O-acetyl group at the branching point, the 3,6-di-O-substituted mannose unit, of an acetylated oligosaccharide by sodium methoxide is significantly slower than that of other acetyl groups. We could separate the 4-O-acetylated branching oligosaccharide from linear isomer using high-performance liquid chromatography. Before and after the de-O-acetylation of the purified branching oligosaccharide, their 1H-NMR signals were sequentially assigned by means of the nuclear Overhauser effect. In the sequential NMR assignment study, we showed that the alpha-1,6-linked mannose unit is attached to the 3-O-substituted unit based on the presence of NOE cross-peak between H1 of the branching mannose unit and H6 of the 3-O-substituted mannose unit. An enzyme-linked immunosorbent inhibition assay of the reactivity of factor 4 serum to C. stellatoidea mannan by several oligosaccharides indicated that the alpha-1,6-branched oligosaccharide and the beta-1,2 linkage-containing oligosaccharides showed inhibitory activity. This result indicates that factor 4 serum, as well as factor 5 and 6 sera, contains antibodies against beta-1,2-linked mannose units which have been reported to participate in pathogenicity via cytokine production and/or adherence. From the assignment results of H1-H2-correlated cross-peaks of oligosaccharides and mannans, the molar ratio of the mannan side chains was proposed. In this study, we demonstrated that the epitope structure of the C. stellatoidea type I strains was the same as that of the C. albicans NIH B-792 (serotype B) strain.

Nuclear and cytosolic calcium signaling induced by extracellular ATP in rat kidney inner medullary collecting duct cells

Using a laser scanning confocal microscopy of fluorescent Ca2+ indicator (Fluo-3-AM) the spatiotemporal Ca2+ dynamics in cultured kidney inner medullary collecting duct cells was investigated. In response to extracellular ATP (100 microM), nuclear (Fln) and cytosolic (Flc) fluorescence intensity increased simultaneously. UTP similarly increased Fln and Flc, but ADP and AMP did not. A ratio between Fln and Flc was about 1.06 +/- 0.03 at rest and increased 1.71 +/- 0.02 at the peak of stimulation (n = 74). In Ca(2+)-free condition, ATP increased Fln and Flc with a smaller peak intensity, but the peak ratio was similar (1.52 +/- 0.03, n = 70). Faster time resolution of 100 ms in line scanning mode did not detect the delay between nuclear and cytosolic Ca2- responses. Our results indicate that nuclear Ca2+ was not diffused from the cytoplasm and that it may be directly released from the nuclear envelope, a possible Ca2+ store.

Y-26763 protects the canine heart from a stunning injury through opening of the KATP channels

The present study describes the protective effects of the ATP-sensitive K+ (KATP) channel opener Y-26763 ((-)-(3S,4R-4-(N-acetyl-N-hydroxyamino)-6-cyano-3,4-dihydro-2,2-dimethyl -2H-1-benzopyran-3-ol), on a model of reversible ischemia/reperfusion injury ('stunned' myocardium). Stunning was caused by 10-min occlusion of the left circumflex coronary artery followed by 3-h reperfusion in pentobarbital anesthetized beagle dogs. This procedure reduced by over 80% myocardial segment function measured by sonomicrometry in control preparations. Y-26763, administered 10 min before the left circumflex coronary artery occlusion, at a dose (3 micrograms/kg, i.v.) lacking significant systemic hemodynamic effects, produced a rapid and marked (80%) recovery of the shortening of the ischemic segment. By contrast, nifedipine (1 microgram/kg plus 0.2 microgram/kg per min, i.v.) did not ameliorate postischemic function. Glibenclamide, administered before Y-26763 at a dose (0.3 mg/kg, i.v.) that did not affect adversely hemodynamics and stunning injury negated the beneficial action of Y-26763. However, glibenclamide failed to do so when administered 2 min before starting reperfusion. The ischemia/reperfusion areas, which were measured by digital image analysis with NIH image software, were similar among experimental groups. Overall, these results indicate that Y-26763 protects the canine myocardium from reversible ischemia/reperfusion injury, probably through activation of myocardial KATP channels which appear to be involved in affording protection during the ischemic insult and not at the reperfusion.

Tumor neutrophil elastase is closely associated with the direct extension of non-small cell lung cancer into the aorta

OBJECTIVE

Neutrophil elastase (NE) is the only neutral protease that is able to degrade insoluble elastin and other extracellular matrix constituents, and thus, may be involved in tumor invasion and metastasis. Using a highly specific and sensitive enzyme immunoassay (EIA), we recently demonstrated that immunoreactive (ir)-NE is produced by non-small cell lung cancer cell lines. We have measured the ir-NE concentration in non-small cell lung cancer tumor extracts and have evaluated its association with disease stage.

METHODS

We measured the ir-NE concentration in 144 non-small cell lung cancer tumor extracts using EIA, which permits the rapid measurement of both the free and alpha1-protease inhibitor (alpha1-PI) complexed form of ir-NE. In 15 clinical T4 (cT4) patients, we also determined the concentration of free ir-NE in tumor extracts using a kit that detects only NE complexed with alpha1-PI and subtracting that value from the total NE concentration.

RESULTS

ir-NE was detected in tumor extracts from 115 of 144 patients, ranging from 0.21 to 23.35 microg/100 mg protein. When the 144 specimens were grouped according to the clinical stage of disease, the ir-NE concentration (mean+/-SE) was significantly higher in those with cT4 disease (n=15; 7.90+/-1.88 microg/100 mg protein) than in those with cT1 (n=29; 1.27+/-0.27; p<0.001), cT2 (n=64; 1.18+/-0.17; p<0.001), or cT3 disease (n=26; 1.99+/-0.38; p<0.003). There was no significant association between the ir-NE concentration and cN-factor or any other clinical features. When the ir-NE concentration in the tumor extracts of the cT4 patients was compared with respect to the tumor invasion sites, the ir-NE level was significantly higher in those with surgical T4 (sT4) disease with aortic invasion (n=4; 17.4+/-3.10) than in those who were down-staged postoperatively (n=5; 4.9+/-1.33; p=0.005) or those with sT4 disease with involvement of other sites (n=6; 4.07+/-1.83; p=0.004). Similar results were observed for the free form of ir-NE.

CONCLUSIONS

These data suggest that NE may be involved in tumor progression of non-small cell lung cancer. Since the aorta is one of the richest sources of polymeric and insoluble elastin, this enzyme may play an active role in the direct extension of the tumor into the aorta.