Disulfide bond formation of thiols by using carbon nanotubes.

Clarification of the interactions between carbon nanotubes (CNTs) and proteinogenic amino acids is a key approach to understanding CNT-protein interactions. Previous studies have addressed the mechanism of the physical adsorption of amino acids onto CNTs. However, little is known about their chemical reactions in aqueous solutions. Here, we established dispersant-free systems to clarify intrinsic CNT-thiol interactions. We demonstrated that the redox reaction of CNTs with cysteine, containing a thiol group, leads to disulfide bond formation between cysteine molecules, even under acidic conditions. The generality of the redox reaction is validated using other thiols such as dithiothreitol and glutathione. The present results suggest that structures of proteins and peptides containing free thiol groups are chemically modified and misfolded on CNT surfaces by this disulfide bond formation in biological systems.

Hiatal hernia following total gastrectomy with Roux-en-Y reconstruction.

Hiatal hernias after total gastrectomy for advanced gastric cancer are very rare. We review a case of a 44-year-old male who presented with dyspnea and chest pain 2 days after total gastrectomy, lower esophagectomy, and splenectomy with retrocolic Roux-en-Y reconstruction approached by a left thoracoabdominal incision for gastric cancer at the cardia. Plain and cross-sectional imaging identified a large hiatal hernia protruding into the right thorax containing left-sided transverse colon and small intestine. Our patient underwent a laparotomy, and after hernia reduction the hiatal defect was repaired by direct suturing. He experienced anastomotic leakage and right pyothorax, but recovered. The potential cause is discussed here and the published literature on this rare complication is reviewed briefly.

Role of c-Jun N-terminal kinase isoforms in the cellular activity of melanoma cell lines.

BACKGROUND: The c-Jun N-terminal kinase (JNK) is thought to be involved in inflammation, proliferation and apoptosis. AIM: To examine the role of JNK isoforms in metastasis, proliferation, migration and invasion of the malignant melanoma (MM) cell lines SK-MEL-28, SK-MEL-3 and WM164, using a kinase-specific inhibitor or isoform-specific small interfering (si)RNAs. RESULTS: SK-MEL-3, a cell line established from metastatic MM, showed slightly increased phosphorylation of both JNK1 and JNK2, whereas WM164, a cell line derived from primary MM, showed significant phosphorylation of JNK1. A JNK inhibitor, SP600125, inhibited cell proliferation of SK-MEL-3 but not SK-MEL-28 or WM164. Transfection of JNK1-specific siRNA reduced the migratory activity of WM164 cells, while silencing of either JNK1 or JNK2 strongly suppressed the invasive activity of SK-MEL-3. CONCLUSIONS: Our study suggests that JNK isoforms have different roles in MM. Metastasis of MM may be regulated by JNK2, while invasion is regulated by both JNK1 and JNK2. JNK1 and JNK2 respectively mediate cell migration and cell proliferation. Further understanding of the specific roles of JNK isoforms in the pathogenesis of MM may lead to the development of therapies targeting specific isoforms.

Axonal protection by Nmnat3 overexpression with involvement of autophagy in optic nerve degeneration.

Axonal degeneration often leads to the death of neuronal cell bodies. Previous studies demonstrated the crucial role of nicotinamide mononucleotide adenylyltransferase (Nmnat) 1, 2, and 3 in axonal protection. In this study, Nmnat3 immunoreactivity was observed inside axons in the optic nerve. Overexpression of Nmnat3 exerts axonal protection against tumor necrosis factor-induced and intraocular pressure (IOP) elevation-induced optic nerve degeneration. Immunoblot analysis showed that both p62 and microtubule-associated protein light chain 3 (LC3)-II were upregulated in the optic nerve after IOP elevation. Nmnat3 transfection decreased p62 and increased LC3-II in the optic nerve both with and without experimental glaucoma. Electron microscopy showed the existence of autophagic vacuoles in optic nerve axons in the glaucoma, glaucoma+Nmnat3 transfection, and glaucoma+rapamycin groups, although preserved myelin and microtubule structures were noted in the glaucoma+Nmnat3 transfection and glaucoma+rapamycin groups. The axonal-protective effect of Nmnat3 was inhibited by 3-methyladenine, whereas rapamycin exerted axonal protection after IOP elevation. We found that p62 was present in the mitochondria and confirmed substantial colocalization of mitochondrial Nmnat3 and p62 in starved retinal ganglion cell (RGC)-5 cells. Nmnat3 transfection decreased p62 and increased autophagic flux in RGC-5 cells. These results suggest that the axonal-protective effect of Nmnat3 may be involved in autophagy machinery, and that modulation of Nmnat3 and autophagy may lead to potential strategies against degenerative optic nerve disease.

Autologous adipose-derived regenerative cells are effective for chronic intractable radiation injuries.

Effective therapy for chronic radiation injuries, such as ulcers, is prone to infection. Stiffness is expected since the therapeutic radiation often involves wider and deeper tissues and often requires extensive debridement and reconstruction, which are not sometimes appropriate for elderly and compromised hosts. Autologous adipose-derived regenerative cells (ADRCs) are highly yielding, forming relatively elderly aged consecutive 10 cases, 63.6±14.9 y (52-89 y), with mean radiation dose of 75.0±35.4 Gy (50-120 Gy) were included with at least 10-month follow-up. Minimal debridement and ADRC injection in the wound bed and margin along with the injection of mixture of fat and ADRCs in the periphery were tested for efficacy and regenerated tissue quality by clinically as well as imaging by computed tomography and magnetic resonance imaging. Uncultured ADRCs of 1.6±1.3×10(7) cells were obtained. All cases healed uneventfully after 6.6±3.2 weeks (2-10 weeks) post-operatively. The done site morbidity was negligible and without major complications, such as paralysis or massive haematoma. The regenerated tissue quality was significantly superior to the pre-operative one and the mixture of fat and ADRCs connected to the intact tissue was very soft and pliable. Mean follow-up at 1.9±0.8 y (0.9-2.9 y) revealed no recurrence or new ulceration after treatment. Thus, the ADRCs treatment for decades-long radiation injuries is effective, safe and improves the quality of wounds.

Anticancer drugs up-regulate HspBP1 and thereby antagonize the prosurvival function of Hsp70 in tumor cells.

The 70-kDa heat shock protein (Hsp70) is up-regulated in a wide variety of tumor cell types and contributes to the resistance of these cells to the induction of cell death by anticancer drugs. Hsp70 binding protein 1 (HspBP1) modulates the activity of Hsp70 but its biological significance has remained unclear. We have now examined whether HspBP1 might interfere with the prosurvival function of Hsp70, which is mediated, at least in part, by inhibition of the death-associated permeabilization of lysosomal membranes. HspBP1 was found to be expressed at a higher level than Hsp70 in all normal and tumor cell types examined. Tumor cells with a high HspBP1/Hsp70 molar ratio were more susceptible to anticancer drugs than were those with a low ratio. Ectopic expression of HspBP1 enhanced this effect of anticancer drugs in a manner that was both dependent on the ability of HspBP1 to bind to Hsp70 and sensitive to the induction of Hsp70 by mild heat shock. Furthermore, anticancer drugs up-regulated HspBP1 expression, whereas prevention of such up-regulation by RNA interference reduced the susceptibility of tumor cells to anticancer drugs. Overexpression of HspBP1 promoted the permeabilization of lysosomal membranes, the release of cathepsins from lysosomes into the cytosol, and the activation of caspase-3 induced by anticancer drugs. These results suggest that HspBP1, by antagonizing the prosurvival activity of Hsp70, sensitizes tumor cells to cathepsin-mediated cell death.

S-carboxymethylcysteine normalises airway responsiveness in sensitised and challenged mice.

S-carboxymethylcysteine (S-CMC) has been used as a mucoregulator in respiratory diseases. However, the mechanism of action of S-CMC on allergic airway inflammation has not yet been defined. In the present study, BALB/c mice were initially sensitised and challenged to ovalbumin (OVA) and, weeks later, re-challenged with OVA (secondary challenge). S-CMC (5-100 mg.kg-1) was administered from 2 days before the secondary challenge through to the day of assay. Mice developed airway hyperresponsiveness (AHR) 6 h after the secondary challenge and increased numbers of neutrophils were present in the bronchoalveolar lavage (BAL) fluid. At 72 h after secondary challenge, mice again developed AHR, but the BAL fluid contained large numbers of eosinophils. S-CMC treatment was found to reduce AHR and neutrophilia at 6 h, as well as eosinophilia and AHR at 72 h. These effects appeared to be dose dependent. Goblet cell hyperplasia, observed at 72 h, was reduced by S-CMC. In BAL fluid, increased levels of interferon-gamma, interleukin (IL)-12 and IL-10 and decreased levels of IL-5 and IL-13 were detected. In conclusion, the data indicate that S-carboxymethylcysteine is effective in reducing airway hyperresponsiveness and airway inflammation at two distinct phases of the response to the secondary allergen challenge in sensitised mice.

Expression of a CD44 variant and VEGF-C and the implications for lymphatic metastasis and long-term prognosis of human breast cancer.

The aim of the present study was to determine whether expression of the CD44 variant v7-v8 (CD44v7-v8) or vascular endothelial growth factor-C (VEGF-C) is associated with long-term prognosis in breast cancer patients. A 10-year follow-up of 91 patients with primary breast cancer who were previously assessed for CD44 expression was undertaken. Immunohistochemical evaluation of VEGF-C expression was performed in 87 of these patients and their long-term prognosis was assessed. The disease-free and overall survival rates were significantly poorer for the CD44v7-v8-positive patients than for the patients negative for this marker. VEGF-C expression was detected in 38 out of the 87 patients (43.7%) with primary human breast cancer. There were no significant differences in tumor size, histological type, axillary lymph node status, presence of lymphatic or venous invasion, or presence of estrogen receptors and progesterone receptors between the VEGF-C-positive and -negative patients. There were also no significant differences in the disease-free or overall survival rates in these patient groups. In conclusion after the 10-year follow-up, expression of CD44v7-v8 was associated with poor prognosis for breast cancer patients. However, there was no association between VEGF-C expression and the clinicopathological factors or prognosis of breast cancer patients.

Down-regulation in human cancers of DRHC, a novel helicase-like gene from 17q25.1 that inhibits cell growth.

Frequent observations of allelic loss in chromosomal band 17q25.1 in a variety of human cancers have suggested that one or more tumor suppressor genes are normally present in this region. Moreover, a locus responsible for hereditary focal non-epidermolytic palmoplantar keratoderma (tylosis oesophageal cancer; TOC), a condition associated with esophageal cancer, has been mapped to the same band. During efforts to sequence, by shot-gun methods, a 1 Mb target region that we had defined as the DNA segment harboring the putative tumor suppressor gene(s) involved in these events, we identified a novel cDNA, DRHC (down-regulated in human cancers), that showed reduced expression in 28 of 95 (29%) cell lines derived from a variety of human cancers. The full-length cDNA, 6275 bp long, was expressed predominantly in thymus and brain. The predicted 1942-amino-acid product exhibited significant sequence homology to yeast enzymes belonging to the DEAD-helicase superfamily, and appeared to be a Uvr/Rep helicase with a DEXDc consensus domain. Transfection of a DRHC expression vector inhibited growth of cancer cells in liquid medium or soft agar. The results suggest that loss of expression of DRHC may play a role in human carcinogenesis.

High prevalence of Epstein-Barr virus in gastric remnant carcinoma after Billroth-II reconstruction.

BACKGROUND: Epstein-Barr virus (EBV) has been detected in about 10% of gastric carcinoma cases worldwide, and a high prevalence of EBV involvement in gastric remnant carcinoma has been reported recently. Details of the background remnant stomach of EBV-positive lesions, however, have not been well clarified. METHODS: We screened 17 consecutive gastric remnant carcinoma lesions resected surgically. To detect EBV, we used in situ hybridization (ISH) for EBV-encoded small RNA1 (EBER-1) and we compared the clinicopathologic feature between EBV-positive and -negative gastric remnant carcinoma cases. RESULTS: EBV was detected in 41.8% (7 of 17) of the lesions by EBER-1 ISH. All 7 EBV-positive lesions developed in the anastomotic site had undergone Billroth-II reconstruction excess 20 years previously (mean 26.4 years). Histologically, all EBV-positive lesions were poorly differentiated adenocarcinomas with intense lymphocyte infiltration. In the adjacent mucosa of carcinomas, moderate or marked intestinal metaplasia was found in 85.7% (6 of 7) of EBV-positive lesions and in 40% (4 of 10) of EBV-negative lesions. CONCLUSIONS: EBV infection is strongly associated with gastric remnant carcinoma. Atrophic change of remnant gastritis in Billroth-II anastomoses is considered to be the carcinogenic background for EBV-positive gastric remnant carcinoma.

Hepatic angiomyolipoma: radiologic and histopathologic correlation.

We present two cases of hepatic angiomyolipoma. Histologic analysis showed that mature adipose tissue occupied 79.0% of the area on the largest cut surface in the first case and 40.2% in the second case. We suggest that the difference in the ratio of adipose tissue volume to its distribution is reflected on diagnostic images.

[Breast cancer].

Neoadjuvant chemotherapy (NAC) represents a new approach based on sound theoretical, pharmacokinetic, and experimental principles. The purpose of NAC is to improve control of the primary site by downstaging and to improve control of micrometastatic disease. NAC has been standard therapy in the management of locally advanced breast cancer. Patients with earlier stage breast cancer may also benefit from treatment with NAC. Recently some investigators have mentioned that NAC can be used instead of adjuvant chemotherapy and would be most appropriate for patients who wish to preserve their breast but who have tumors too large for breast conserving surgery. In this article, we reviewed the present status of NAC (indication, clinical response, pathologic response, survival, possibility of breast conservation, prognostic/predictive factors, neoadjuvant endocrine therapy) and discussed several unanswered questions on NAC (survival benefit, optimal number of treatment cycles, optimal regimens) and future direction. Combined modality therapy including NAC appears to provide excellent local control, the possibility of breast conservation, and, probably, an increased survival rate, at least for some subsets of patients. Furthermore, through sequential sampling, NAC provides indeed the opportunity to identify molecular mechanisms associated with pathologic response and to study the possibility to guide the choice for induction treatment and patient populations submitted to neoadjuvant chemotherapy.

Malolactomycin D, a potent inhibitor of transcription controlled by the Ras responsive element, inhibits Ras-mediated transformation activity with suppression of MMP-1 and MMP-9 in NIH3T3 cells.

To search for anti-cancer agents, a screening system for Ras signal inhibitors was developed using a NIH3T3 cell line with an introduced reporter gene which is controlled by the Ras-responsive element (RRE). With this screening system, malolactomycin D was identified as a selective inhibitor of transcription from the RRE. This compound was found to preferentially inhibit the anchorage-independent growth rather than the anchorage-dependent growth of Ras-transformed NIH3T3 cells. The expression of matrix metalloproteinases MMP-1 and MMP-9, which have RRE in their promoters, were reduced by treatment with malolactomycin D at the translational and transcriptional levels. Analysis of the activity of mitogen-activated protein (MAP) kinases, which play important roles in transduction of the Ras signal, showed that malolactomycin D inhibits the activation of p38 MAP kinase and Jun N-terminal-kinase (JNK) but not extracellular signal-regulated kinase 1 or 2 (ERK1 or 2). These findings suggest that by inhibiting the pathway that leads to the activation of p38 MAP kinase and JNK, malolactomycin D suppresses the expression of MMPs. Since MMPs play important roles in metastasis and maintenance of the microenvironment of tumor cells, both of which facilitate tumor growth, the inhibition of MMPs by malolactomycin D is believed to contribute to its ability to inhibit Ras-mediated tumorigenesis.

Allelic losses as prognostic markers for breast cancers.

Specific allelic losses in the DNA of tumor cells are potential indicators of postoperative prognosis. Patients whose tumors showed allelic losses at 1p34, 3p25, 8p22, 13q12, 17p13.3, or 17q21.1 had a significantly higher risk of postoperative mortality than women whose tumors retained both alleles at those loci (the 5-year mortality rates in patients with loss vs those with retention were: at 1p34, 23% vs 10%, P = 0.0100; at 3p25, 22% vs 9%, P = 0.0014; at 8p22, 24% vs 7%, P = 0.0177; at 13q12, 19% vs 8%, P = 0.0093; at 17p13.3, 19% vs 9%, P = 0.0078; and at 17q21.1, 17% vs 10%, P = 0.0475). Allelic losses at these loci may serve as negative prognostic indicators to guide postoperative management, especially in the selection of patients who should be offered intensive adjuvant therapy.

Association of allelic losses at 3p25.1, 13q12, or 17p13.3 with poor prognosis in breast cancers with lymph node metastasis.

To identify specific allelic losses that might correlate with postoperative mortality of patients with node-positive breast carcinomas, we examined tumors from a cohort of 263 such patients, who were followed clinically for 5 years postoperatively, for allelic losses among 18 microsatellite markers. Patients whose tumors had lost an allele at 3p25.1, 13q12, or 17p13.3 had significantly higher risks of mortality than those whose tumors retained both alleles at those loci. At 3p25.1, the 5-year mortality rate was 33.8% among patients with losses vs. 16.8% with retention (P = 0.0154); at 13q12, 30.3% vs. 13.0% (P = 0.0241); and at 17p13.3, 30.4% vs. 16.2% (P = 0.0243). Combined losses at 3p25.1 and 17p13.3 increased the predicted postoperative mortality risk by a factor of 4.9 (5-year mortality rate of 38.2% vs. 8.0%, P = 0.0006), and combined losses at 3p25.1 and 13q12 raised the predicted postoperative mortality risks by a factor of 2.9 (34.7% vs. 12.7%, P = 0.0441). These data indicate that loss of heterozygosity (LOH) at any one or a pair of loci at 3p25.1, 13q12, or 17p13.3 is a significant predictor of postoperative mortality for breast-cancer patients.

Possible involvement of a single histidine residue in the P-type Na+-ATPase of a facultatively anaerobic alkaliphile, Exiguobacterium aurantiacum.

Effect of various inhibitors on the P-type Na+-ATPase of a facultatively anaerobic alkaliphile, Exiguobacterium aurantiacum, was examined. The ATPase was extremely sensitive to p-chloromercuriphenylsulfonic acid, a modifier of SH-group. The enzyme was also sensitive to diethylpyrocarbonate, and analysis of the inhibition kinetics by the drug indicated that modification of a single histidine residue per ATPase molecule was sufficient to inactivate the enzyme.