The contribution of proteasomal impairment to autophagy activation by C9orf72 poly-GA aggregates

BACKGROUND

Poly-GA, a dipeptide repeat protein unconventionally translated from GGGGCC (G4C2) repeat expansions in C9orf72, is abundant in C9orf72-related amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) (C9orf72-ALS/FTD). Although the poly-GA aggregates have been identified in C9orf72-ALS/FTD neurons, the effects on UPS (ubiquitin-proteasome system) and autophagy and their exact molecular mechanisms have not been fully elucidated.

RESULTS

Herein, our in vivo experiments indicate that the mice expressing ploy-GA with 150 repeats instead of 30 repeats exhibit significant aggregates in cells. Mice expressing 150 repeats ploy-GA shows behavioral deficits and activates autophagy in the brain. In vitro findings suggest that the poly-GA aggregates influence proteasomal by directly binding proteasome subunit PSMD2. Subsequently, the poly-GA aggregates activate phosphorylation and ubiquitination of p62 to recruit autophagosomes. Ultimately, the poly-GA aggregates lead to compensatory activation of autophagy. In vivo studies further reveal that rapamycin (autophagy activator) treatment significantly improves the degenerative symptoms and alleviates neuronal injury in mice expressing 150 repeats poly-GA. Meanwhile, rapamycin administration to mice expressing 150 repeats poly-GA reduces neuroinflammation and aggregates in the brain.

CONCLUSION

In summary, we elucidate the relationship between poly-GA in the proteasome and autophagy: when poly-GA forms complexes with the proteasome, it recruits autophagosomes and affects proteasome function. Our study provides support for further promoting the comprehension of the pathogenesis of C9orf72, which may bring a hint for the exploration of rapamycin for the treatment of ALS/FTD.

Non-coding RNAs: New players in mitophagy and neurodegeneration

Mitophagy controls mitochondrial quality to maintain cellular homeostasis, while aberrations in this process are responsible for neurodegenerative diseases. Mitophagy is initiated through the recruitment of autophagosomes in a ubiquitin-dependent or ubiquitin-independent manner under different stress conditions. Although the detailed molecular mechanisms of how mitophagy processes influence neurodegeneration remain largely uncharacterized, there is mounting evidence indicating that non-coding RNAs (ncRNAs), a variety of endogenous regulators, including microRNAs and long non-coding RNAs, extensively participate in mitophagy processes and play pivotal roles in the aging process and neurodegenerative diseases. Here, we reviewed the major mitophagy pathways modulated by some classical and newly found ncRNAs and summarized the diverse mechanisms in a regulatory network. We also discussed the generalizability of ncRNAs in the development of common neurodegenerative diseases related to proteotoxicity and the importance of mitophagy in the pathogenesis of these diseases. In summary, we propose that ncRNAs act as linkers between mitophagy and neurodegeneration, showing the potential therapeutic application of mitophagy regulation mediated by ncRNAs in neurodegenerative diseases.

miR-34a-5p regulates PINK1-mediated mitophagy via multiple modes

AIMS

PTEN induced putative kinase 1 (PINK1)-mediated mitophagy process is tightly associated with various age-dependent diseases in mammals. The roles of miRNAs (miRNAs) in the PINK1-mediated mitophagy process are not fully understood. Here we discovered that miR-34a-5p suppresses PINK1 expression directly though two post-transcriptional non-classical binding modes, resulting in inhibition of PINK1-mediated mitophagy process.

MAIN METHODS

For in vivo experiments, brains were dissected from 8 weeks old and 40 weeks old C57BL/6 male mice to measure miR-34a-5p expression and PINK1 expression. For in vitro experiments, overexpression of miR-34a-5p mimics in HEK293 cells was performed to investigate the effect of miR-34a-5p on PINK1 expression and its regulatory mechanism, parkin recruitment and mitophagy process.

KEY FINDINGS

The level of miR-34a-5p was upregulated and the level of PINK1 mRNA was downregulated in brains of aged mice. Both the 3'-untranslated region (3'UTR) and the Coding DNA sequence (CDS) of PINK1 mRNA were bound to the non-seed region of miR-34a-5p, rather than the seed region, resulting in a decrease in PINK1 expression. Endogenous miR-34a-5p knockout increased PINK1 expression. Further results indicated that miR-34a-5p inhibits mitophagy process by reduction of PINK1. miR-34a-5p hinders phosphorylated Ser65-ubiquitin (pS65-Ub) accumulation, prevents the mitochondrial recruitment of Parkin, attenuates ubiquitination and delays the clearance of damaged mitochondria.

SIGNIFICANCE

We firstly found that miR-34a-5p suppresses PINK1 directly and further regulates mitophagy through non-canonical modes. This finding hints at a crucial role of miR-34a-5p implicated in accelerating the pathogenesis of age-related neurological diseases.

MiR-1205 functions as a tumor suppressor by disconnecting the synergy between KRAS and MDM4/E2F1 in non-small cell lung cancer

Activated KRAS is frequently observed and paralleled by inactivating of tumor suppressors in lung cancer, while the mechanisms remained elusive. Here, our study revealed a microRNA was involved in KRAS overexpression, activation of KRAS signaling and its synergy with inactivating of tumor suppressor genes. miR-1205 was selected by its sequence-dependent inhibition on KRAS and negative clinical correlation with KRAS. A549 and H460 cells carrying mutant KRAS, were sensitive to the growth inhibition and G1/S arrest induced by miR-1205. Target analysis revealed that miR-1205 could simultaneously downregulate the expression levels of MDM4 and E2F1, which were downstream of KRAS and synergistic with KRAS. Silencing of MDM4 or E2F1 inhibited cellular proliferation. MiR-1205 decreased the protein levels of MDM4 and E2F1 via directly binding to the coding sequence of E2F1 and 3'UTR of MDM4. Meanwhile, blocking RAS-MAPK signaling using KRAS siRNA or ERK1/2 inhibitor exerted similar inhibitory effects on MDM4 and E2F1. Forced expression of KRAS partially restored the inhibition of miR-1205 on MDM4 and E2F1. Overexpression of KRAS, MDM4 or E2F1 could partially rescued the growth inhibition of miR-1205 in vitro. More importantly, miR-1205 strongly inhibited the tumor growth of A549 xenografts in nude mice and decreased the protein levels of KRAS, MDM4 and E2F1 in tumor tissues. Together, our study firstly confirmed a potential synergy between KRAS and MDM4/E2F1 which are p53/RB inactivators in non-small cell lung cancer, and identified miR-1205 as a potent destructor of this synergy, making miR-1205 function as a tumor suppressor in vitro and in vivo.

MiR-4465 directly targets PTEN to inhibit AKT/mTOR pathway-mediated autophagy

Autophagy plays an important role in maintaining cell function. Abnormal autophagy leads to cell dysfunction and is associated with many diseases such as tumors, immunodeficiency diseases, lysosomal storage disorders, and neurodegenerative diseases. Autophagy is precisely regulated, and PTEN plays an important role in regulating autophagy. As noncoding small RNAs, miRNAs play an important role in the fine regulation of cellular processes. However, the mechanism of the miRNA regulation of PTEN-related autophagy has not been fully elucidated. In this study, our results showed that miR-4465 significantly inhibited the expression of PTEN, upregulated phosphorylated AKT, and thereby inhibited autophagy by activating mTOR in HEK293, HeLa, and SH-SY5Y cells. Further studies indicated that miR-4465 reduced PTEN mRNA levels through posttranscriptional regulation via directly targeting the 3'-UTR. Our novel findings provide useful hints for the comprehensive elucidation of the molecular mechanism of miRNA-regulated PTEN-related autophagy and may also provide some new insights for the exploration of miRNAs in the treatment of PTEN-related diseases.

The expression of HDAC7 in cancerous gastric tissues is positively associated with distant metastasis and poor patient prognosis

PURPOSE

To characterize the expression patterns of HDAC7 in patients with gastric cancer and evaluate the prognostic value of HDAC7 in gastric cancer.

METHODS

The expression of histone deacetylase 7 (HDAC7) was detected in paraffin-embedded gastric cancer samples from 86 patients by immunohistochemistry, and the differences in the expression of HDAC7 between cancerous and corresponding adjacent noncancerous tissues were compared using the Wilcoxon matched-pairs signed rank test. The correlation between HDAC7 expression and Ki-67 expression or clinicopathologic characteristics was evaluated using a Spearman rank correlation test. Prognostic outcomes that correlated with HDAC7 were examined using a Kaplan-Meier analysis and Cox proportional hazards model. Moreover, the effects of HDAC7 on the proliferation, migration and invasion of gastric cancer cells were investigated in vitro using human gastric carcinoma AGS cells.

RESULTS

We found that HDAC7 was downregulated in cancerous gastric tissues (P = 0.0019). However, the expression of HDAC7 in cancerous gastric tissues positively correlated with Ki-67 expression (P = 0.0325) and distant metastasis (P = 0.020). Moreover, overall survival was shorter for patients expressing higher levels of HDAC7 in cancerous tissues (P = 0.042). Mechanistically, the disruption of the HDAC7 gene attenuated the capacity of cell growth, migration and invasion and induced G0/G1 arrest in AGS cells. Conversely, forced ovperexpression of HDAC7 promoted cell growth, migration and invasion and G1/S transition in AGS cells.

CONCLUSIONS

These results indicate that high HDAC7 expression in cancerous gastric tissues correlates with distant metastasis and predicts a poor prognosis for patients with gastric cancer.

Hepatic carcinoma-associated fibroblasts induce IDO-producing regulatory dendritic cells through IL-6-mediated STAT3 activation

Although carcinoma-associated fibroblasts (CAFs) in tumor microenvironments have a critical role in immune cell modulation, their effects on the generation of regulatory dendritic cells (DCs) are still unclear. In this study, we initially show that CAFs derived from hepatocellular carcinoma (HCC) tumors facilitate the generation of regulatory DCs, which are characterized by low expression of costimulatory molecules, high suppressive cytokines production and enhanced regulation of immune responses, including T-cell proliferation impairment and promotion of regulatory T-cell (Treg) expansion via indoleamine 2,3-dioxygenase (IDO) upregulation. Our findings also indicate that STAT3 activation in DCs, as mediated by CAF-derived interleukin (IL)-6, is essential to IDO production. Moreover, IDO inhibitor, STAT3 and IL-6 blocking antibodies can reverse this hepatic CAF-DC regulatory function. Therefore, our results provide new insights into the mechanisms by which CAFs induce tumor immune escape as well as a novel cancer immunotherapeutic approach (for example, targeting CAFs, IDO or IL-6).

Integrated flexible ocular coil for power and data transfer in retinal prostheses

A microfabricated and fully-implantable coil for use as a power and data transfer component for retinal prostheses is presented. Compared with traditional hand-made ocular coils, this parylene-based device is thin and flexible with 10 turns of thin-film metal wires and a thickness of less than 10 μm. In addition, the entire coil structure can be heat-formed on a mold to match the eye's curvature for extraocular implantation. Because it is made using parylene thin-film technology, this coil can be directly integrated with multielectrode arrays and with parylene-based packages incorporating application specific integrated circuits (ASICs) or discrete electrical components such as chip capacitors. This coil thus enables the fabrication and implantation of a fully microfabricated system for retinal prostheses.

A Reconstruction Method Using Musculopericranial Flaps that Prevents Cerebrospinal Fluid Rhinorrhea and Intracranial Complications after Extended Anterior Skull Base Resection

Anterior skull base defects after extended anterior skull base resection including unilateral orbit and the dura were reconstructed using the temporal musculopericranial (TMP) flaps or frontal musculopericranial (FMP) flap in 14 patients. Dural defect was reconstructed with the TMP or FMP flap by making it overlap on the remaining dura around the defects. These flaps were also used, in principle, for the separation of the nasal cavity. For bone defects on the anterior skull base, a bone graft was transplanted in the place between the flap for dural reconstruction and the flap for the separation of the nasal cavity. Bone grafting was nor performed in patients who had an extensive defect and for whom a free flap was used for the separation. After surgery, CSF rhinorrhea did not occur in the 14 patients. Twelve patients did not develop any postoperative complications. Two patients had epidural abscess, but with debridement and the drainage to the nasal cavity, they did not develop severe intracranial complications. We conclude that reconstruction using musculopericranial flaps is a reliable and versatile method with minimum invasion and the shortest operation hours. In particular, musculopericranial flap for dura reconstruction was highly efficacious for the prevention of CSF rhinorrhea.

Surgical treatment for epidural abscess in the posterior cranial fossa using trapezius muscle or musculocutaneous flap

Two patients developed an epidural abscess in the posterior cranial fossa following tumor dissection from the occipital region of the head and underwent surgical treatment. After debridement of necrotic and infectious tissues inside the abscess was performed, the empty cavity was filled and the tissue defect was reconstructed by using a trapezius muscle flap or a trapezius musculocutaneous flap. Both patients had good clinical results, and their abscesses were healed. The trapezius muscle flap and trapezius musculocutaneous flap were quite useful in the treatment for epidural abscess in the posterior cranial fossa.

Evaluation with three-dimensional computed tomography after anterior skull base reconstruction using two musculopericranial flaps and a grafted bone

Postoperative evaluation by three-dimensional (3D) computed tomography (CT) was performed in 15 patients who underwent anterior skull base reconstruction using two musculopericranial flaps and a grafted bone sandwiched between the two flaps. Especially in the case of large bone grafts (4 x 4 cm or more), the graft was positioned with the convex side facing upward into the cranial cavity to avoid creating an intracranial dead space. The extent of the absorption and changes in the contour of the grafted bone were evaluated. Imaging was done at a CT level of 150 using a Proceed 3-D CT scanner (Yokogawa Medical Co., Tokyo, Japan). Donor bone for grafting to the skull base was harvested the cranium in 10 patients and the ilium in 5 others. Patients ranged in age from 7 to 76 years (mean, 47); there were 10 men and 5 women. The grafted bone ranged in size from 1 x 2 cm to 5 x 8 cm (1 x 2 cm to about 4 x 3 cm: 10 patients; 4 x 4 to about 5 x 8 cm: 5 patients).No marked absorption of grafted bone was seen in these 15 patients, and no brain hernia occurred. In patients with large bone grafts (4 x 4 cm to about 5 x 8 cm), a graft that had been positioned with the convex side facing upward into cranial cavity at the time of transplant was subsequently observed to be transformed into a downward convex contour of normal skull base. Fostoperative infection did not occur because of the dead space nor were there any symptom of pressure on the brain because of the upward convexity of the grafted bone.The present reconstructive method is not only a minimum invasive but also a safe and reliable method for anterior skull base surgery.

Identification of specific immune responses in monoclonal gammopathy of undetermined significance with therapeutic implications

8103

Background: Monoclonal gammopathy of undetermined significance (MGUS) is a benign condition with only 30% patients developing symptomatic multiple myeloma (MM). The events leading to the transformation from MGUS to MM remain unclear, however several evidences have supported the idea that immune surveillance play a role in preventing progression. Therefore, identification of antigenic targets with immune response in MGUS may provide insight into disease biology and immune-based therapeutic applications. Methods: Using the Serological identification of antigen by Recombinant Expression cloning (SEREX) technique, we have screened a MM cDNA library with 3 MGUS patients sera. Results: We have identified 11 gene products with an antibody response in MGUS. The response appeared to be directed against intracellular proteins involved in apoptosis (SON, Hip1), DNA and RNA binding proteins (KIAA0530, GPATC4), signal transduction regulators (AKAP11), developmental proteins (OFD1), transcriptional co-repressors (IRF2BP2), protein of the ubiquitin-proteosome pathways (PSMC1). We have further analyzed frequency of antibody response against these antigens in additional 26 MGUS sera, 10 newly diagnosed, 11 post-transplant remission and 12 relapsed MM patients and 25 normal donors. Whereas an antibody response was observed against OFD1 (20.6%), KIAA0530 (10.3%), AKAP11 (10.3%) and GPATC4 (6.8%) in MGUS patients, no responses were observed in normal donors or MM patients except against OFD1 in 3 post transplant patients. We have further focused our studies on OFD1, a developmentally expressed Hedgehog (Hh)-pathway-related protein with most frequent antibody response. We have previously showed that Hh-pathway genes are involved in development of MGUS. Our microarray analysis showed that OFD1 and other Hh pathway-related genes (Sonic, Smothened, Patched, Gli-1 and Gli-3) are selectively expressed in MM cell lines and primary cells. We have further evaluated a specific inhibitor of Hh- pathway, Cyclopamine, in MM and observed an inhibition of the proliferation in 5 MM cell lines with an IC50 between 13 - 20 μM. Conclusion: We have confirmed a specific immune response in MGUS and have identified a novel therapeutic target for treatment of MM.

No significant financial relationships to disclose.

Water quality estimation in consideration of pollutant runoff and internal production in Lake Biwa, Japan

Lake Biwa is the largest lake in Japan, and water quality in the lake is heterogeneous. Therefore, it is important for water quality management that spatial distribution of water quality in the lake should be clearly understood. The objectives of this study are to show a methodology and to develop a simulation system to calculate COD distribution in Lake Biwa taking internal COD production into consideration. This study also aims to examine transition of COD in the lake using the simulation system. In the simulation system, runoff loads of COD from the Lake Biwa basin are calculated by Macro Model for each tributary. The external COD concentration in 233 inshore meshes of the Lake Biwa water surface was calculated using the runoff loads. The internal COD was calculated using relationships among limiting nutrients, chlorophyll-a and COD. Then, the spatial distribution of water quality in Lake Biwa was calculated both for the external and internal COD by spline technique. Simulations using the system were implemented for 1986-1998, and a clear difference in characteristics between a drought year and a flood year was shown. In the result, it was shown that the simulation system developed here was available to calculate COD distribution in Lake Biwa, and that it had the possibility to explain the recent phenomenon of COD increase in the lake.

Lenalidomide and bortezomib induce osteoclast cytotoxicity and decrease BAFF secretion in osteoclasts in human multiple myeloma: Clinical implications

7606

Background: Myeloma bone disease is caused by an enhanced osteoclast (OCL) activation, leading to osteolytic bone lesions. OCL have recently been reported to produce abundant B-cell activating factor (BAFF) in the bone marrow microenvironment that is important for myeloma cell growth and survival (Blood 106, 1021–30, 2005; ASH2005, #627). The proteasome inhibitor bortezomib (PS341, Velcade) has potent anti-myeloma activity with impressive clinical responses. A recent study indicated that bortezomib has inhibitory effects on OCL (ASH 2005, #2488). Lenalidomide (CC-5013, Revlimid) is an immunomodulatory derivative of thalidomide that has shown promising anti-myeloma effects in patients with relapsed or refractory multiple myeloma (MM) (ASH 2005, #6 & #1565). However, the effect of lenalidomide on human OCL lineage is unknown. Therefore, the aim of this study is to investigate the effect of lenalidomide and bortezomib on human OCL. Methods: OCL formation from healthy donors and MM patients were stimulated with RANKL (50ng/ml) and GM-CSF (10ng/ml) in 20% FBS/RPMI. Cells were incubated with lenalidomide 2μM or bortezomib 2nM, alone and in combination, for two weeks followed by [3H]thymidine uptake assay to measure growth inhibition of OCL. Similar experiments were also performed in cocultures of CD138-purified cells from MM patients with OCL, in the presence or absence of lenalidomide and bortezomib. In addition, ELISA was performed to measure cytokine release of BAFF produced by OCL in these cultures. Results: OCL growth was decreased by lenalidomide (n=6) (median 49.2%, range 20–62.5%; coculture: 53% and 35%) as well as bortezomib (96 and 49%; coculture 63 and 59%) and by the combination of both drugs (95 and 55%; coculture 42 and 44%). BAFF secretion was dramatically decreased in cultures treated with lenalidomide 2μM (n=3) (median 72%, range 61–75.9%). Conclusions: These results indicate that lenalidomide and bortezomib inhibit OCL growth and survival. Importantly, lenalidomide and bortezomib also block growth and survival of MM cells cocultured with OCL, suggesting that lenalidomide may inhibit OCL growth and survival through inhibition of BAFF and may prevent development of osteolytic lesions in MM.

No significant financial relationships to disclose.

Therapeutic targeting of CD70 and CD27-CD70 interactions with the monoclonal antibody SGN-70 in Waldenstrom’s Macroglobulinemia (WM)

2509

Background: WM represents a lymphoplasmacytic lymphoma characterized by a monoclonal IgM gammopathy and possesses a mast cell component that may contribute to its pathogenesis. The tumor necrosis factor (TNF) receptor family member, CD27, is a transmembrane co-stimulatory molecule that is also secreted in a soluble form (sCD27). Recent evidence has suggested that interactions between CD27 and its TNF-like ligand, CD70, play a critical role in regulating B-cell activation and survival, and therefore, may provide a viable therapeutic target for the treatment of WM. Methods: Patients with the consensus panel diagnosis of WM who provided written consent were evaluated. ELISA assay kits were obtained from Bender MedSystems. Flow cytometric analysis, RT-PCR, and calcein ADCC assays were performed as previously described (Santos et al, in press). Results: By ELISA, WM patients displayed dramatically higher levels of sCD27 in their sera (median 7.45, range 0–19.42 U/ml) versus healthy donors (median 0, range 0–2.78 U/ml; p = 2.5 × 10−7). CD27 was expressed in 7/7 patients using RT-PCR analysis, and on the tumor cell surface of 5/12 patients. CD70, the target for CD27, was widely expressed on tumor cells (6/6) and mast cells (10/11) using flow cytometric analysis. To define the functional role of sCD27 in WM, we cultured BCWM.1 (CD27−CD70+) WM cells, LAD1 (CD27−CD70+) mast cells, and primary tumor and mast cells (CD70+) isolated from WM patients with sCD27 (0.1–50 ug/mL), and observed no effect on their proliferation or induction of apoptosis. However, culture of LAD1 and primary WM mast cells (10/10) with sCD27 resulted in marked upregulation of two TNF family ligands which support the growth and survival of WM cells: CD40L (CD154) and a proliferation induction ligand (APRIL). Importantly, the anti-CD70 mAb SGN-70 (1 ug/ml) inhibited this upregulation by sCD27, establishing the specificity of the CD27-CD70 interaction. In addition, SGN-70 demonstrated significant ADCC against BCWM.1 WM cells at dose levels up to 20 ug/ml. Conclusions: Taken together, these studies suggest a novel functional role for sCD27 in the pathogenesis of WM, and demonstrate the feasibility of targeting CD70 and sCD27-CD70 interactions with the SGN-70 monoclonal antibody.

[Table: see text]

Novel model to evaluate changes in gene expression profile of myeloma cells in vivo following interaction with human BM microenvironment

7613

Background: Interaction between multiple myeloma (MM) cells and the bone marrow (BM) microenvironment plays a critical role in promoting MM cell growth, survival, migration and development of drug resistance. This interaction within the bone marrow milieu is unique and its understanding is important in evaluating effects of novel agents in vitro and in vivo. We here describe a novel murine model that allows us to study the in vivo expression changes in MM cells within the human BM milieu. Methods: In our model, BM stromal and IL-6-dependent human MM cell line, INA-6, tranduced with green fluorescent protein (INA-6 GFP+) was injected in human fetal bone chip implanted into SCID mice. At different time points the bone chip was retrieved, cells flushed out and GFP+ MM cells were separated by flow cytometry or purified by CD138 MACS microbeads. Similar isolation process was used on INA-6 GFP+ cells cultured in vitro and used as control. Total RNA was isolated from these cells and gene expression profile analyzed using the HG-U133 array chip (Affymetrix). Results: We report that interaction between INA-6 cells and the BM microenvironment in vivo induced significant changes in expression profile; specifically, we observed up-regulation of genes implicated in cell growth; DNA transcription; chromosome structure; cell-cell signaling and adhesion. We also observed down-regulation of genes involved in apoptosis and cell death. To determine which biological pathways are modulated by interaction between MM cells and human stroma, all genes were subjected to Ingenuity Pathway Analysis. Our results indicate that the most relevant pathways modulated by the interaction between MM cells with BMSCs are involved in cell-cycle regulation, apoptosis and integrin signaling, as well as with IL-6, IGF1 and PI3K/AKT, p38-MAPK and ERK/MAPK-mediated pathways. These results are consistent with previously observed in vitro cell signaling studies. Conclusions: Taken together these results highlight the ability of BM microenvironment to modulate the gene expression profile of the MM cells in vivo. This model now provides us with an opportunity to study in vivo effects of novel agents on MM cells expression profile, to pre-clinically characterize their activity.

No significant financial relationships to disclose.

Abnormal Temperature Dependence of Photoemission Intensity Mediated by Thermally Driven Reorientation of a Monomolecular Film

The photoemission intensities of organic molecular layers generally obey the Debye-Waller temperature dependence but not always. With the example of a monomolecular film formed from [1,1';4',1''-terphenyl]-4,4''-dimethanethiol, we show that pronounced deviations from Debye-Waller temperature behavior are possible and are likely caused by temperature-dependent changes in molecular orientation.

Strong temperature dependence of irradiation effects in organic layers

Radiation damage of self-assembled monolayers, which are prototypes of thin organic layers and highly organized biological systems, shows a strong dependence on temperature. Two limiting cases could be identified. Reactions involving transport of single atoms and small fragments proceed nearly independent of temperature. Reactions requiring transport of heavy fragments are, however, efficiently quenched by cooling. We foresee the combined use of temperature and irradiation by electrons or photons for advanced tailoring of self-assembled monolayers on surfaces. In addition, our results have direct implications for cryogenic approaches in advanced electron and x-ray microscopy and spectroscopy of biological macromolecules and cells.

Depth distribution of irradiation-induced cross-linking in aromatic self-assembled monolayers

Pristine and strongly irradiated self-assembled monolayers of [1,1':4',1' '-terphenyl]-4,4' '-dimethanethiol (TPDMT) on Au have been characterized by near-edge X-ray absorption fine structure spectroscopy using partial electron yield acquisition mode. The TPDMT films were found to be extremely stable toward electron irradiation, which is explained by cross-linking between the aromatic backbones. In addition, we assume that a large delocalization and a strong relaxation of the initial electronic excitations in the densely packed film contributed to the film stability. The data analysis implies an inhomogeneous distribution of the irradiation-induced dehydrogenation and cross-linking of the terphenyl moieties in the TPDMT film, being most pronounced close to the film-ambient interface. The inhomogeneity was explained by quenching of the electronically excited C-H states via dipole-dipole interaction with the states' image at the metal surface, which has a reduced probability with increasing separation from the metal surface. Generally, the results suggest the importance of relaxation processes for the response of self-assembled monolayers to ionizing radiation.

Jab1 expression is associated with inverse expression of p27(kip1) and poor prognosis in epithelial ovarian tumors

PURPOSE

Jab1 (Jun activation domain-binding protein 1) has been described as a coactivtor of AP1 transcription factor, and is a subunit of a large protein complex (called the COP9 signalosome). Recent study (K. Tomoda et al., Nature (Lond.), 398: 160-165, 1999) found that Jab1 protein can cause breakdown of p27(kip1) protein in mammalian cells. To investigate whether Jab1 expression is correlated with p27(kip1) protein levels as well as how it might be clinically relevant, we evaluated the expression of Jab1 in a group of epithelial ovarian tumors.

EXPERIMENTAL DESIGN

Immunohistochemical analysis was performed in 80 cases of ovarian tumors (33 benign ovarian tumors and 47 ovarian carcinomas). Twenty-six of the 80 cases were evaluated by Western blot analysis.

RESULTS

Jab1 overexpression was detected in 68.1% (32 of 47) of malignant tumors and 33.3% (11 of 33) of benign tumors. The positive ratio of Jab1 was increased from benign to malignant ovarian tumors (P = 0.002). A negative correlation between Jab1 and p27(kip1) expression was found in both benign (P = 0.003) and malignant (P = 0.002) ovarian tumors. No significant correlation was observed between Jab1 overexpression and clinicopathological parameters. Kaplan-Meier survival analysis showed that Jab1 overexpression was significantly associated with poor prognosis of patients (P = 0.049).

CONCLUSIONS

Jab1 expression is inversely correlated with p27(kip1) expression levels, and Jab1, as a negative regulator of p27(kip1), may be associated with the progression and prognosis of epithelial ovarian tumors.

Cryopreserved cultured epidermal allografts achieved early closure of wounds and reduced scar formation in deep partial-thickness burn wounds (DDB) and split-thickness skin donor sites of pediatric patients

Burn treatment in children is associated with several difficulties, e.g. available skin replacement is small, donor area could expand, and subsequent hypertrophic scar and contracture could become larger along with their physical growth. In order to have better clinical results, the authors prepared cryopreserved cultured epidermal allografts from excess epidermal cells of other patients, and applied the epidermal allografts to 55 children, i.e. 43 cases of deep partial-thickness burn wounds (DDB) due to scald burn and 12 cases with split-thickness skin donor sites. In the 43 DDB patients, epithelialization was confirmed 9.1+/-3.6 days (mean+/-S.D.) after treatment. In 10 of the 43 patients, epithelialization was comparable between the area which received the epidermal allografts (grafted area) and the area which did not receive the epidermal allografts but was covered with usual wound dressing (non-grafted area). As a result, epithelialization day was 7.9+/-1.7 in grafted areas and 20.5+/-2.3 in non-grafted areas. In the 12 patients with split-thickness skin donor sites, epithelialization was confirmed 6.3+/-0.9 days after treatment. Epithelialization of the grafted and non-grafted areas was comparable in 8 of the 12 patients, and it was 6.5+/-1.1 days and 14.1+/-1.6 days, respectively. In these 10 DDB patients and 8 split-thickness skin donor site patients, redness and scar formation were also milder in the grafted area. The 55 patients have been followed up for 1-8 years (mean, 4.75 years), and scar formation was suppressed in both DDB and split-thickness skin donor sites. These findings showed that cryopreserved cultured epidermal allografts achieve early closure of the wounds and good functional outcomes.

Implication of malignancy and prognosis of p27(kip1), Cyclin E, and Cdk2 expression in epithelial ovarian tumors

OBJECTIVE

The aim of this study was to further evaluate whether the expression of p27(kip1), cyclin E, and cdk2 is related to the malignancy of ovarian tumors and whether their expressions, alone or in combination, are associated with prognosis in epithelial ovarian carcinoma.

METHODS

Immunohistochemical analysis using anti-p27(kip1), anti-cyclinE, and anti-cdk2 antibodies was carried out for 103 cases consisting of benign, borderline, and malignant ovarian tumors, and Western blot analysis and cdk2 activity assay were performed in 26 fresh ovarian tumor samples.

RESULTS

p27(kip1) expression was reduced in ovarian carcinomas in contrast to benign and borderline tumors. The expression of cyclin E and cdk2 gradually increased from benign to borderline to malignant tumors. Kaplan-Meier survival analysis showed that patients with p27(kip1) expression had a high overall survival rate. Patients with cyclin E overexpression had a low overall survival rate. When the combination of these proteins was analyzed, patients with the p27(kip1) (-)/cyclin E (++)/cdk2 (++) phenotype were significantly associated with the poorest overall survival. In multivariate Cox regression analysis, the combined phenotype of p27(kip1) (-)/cyclin E (++)/cdk2 (++) was independently related to poor prognosis.

CONCLUSIONS

Our results suggest that loss of p27(kip1) expression and overexpression of cyclin E or cdk2 were significantly associated with malignancy in ovarian tumors. p27(kip1) and cyclin E proteins may be valuable prognostic factors for epithelial ovarian carcinoma patients. Furthermore, the combined evaluation of p27(kip1)/cyclin E/cdk2 may provide the most important prognostic implication.

Cyclin D1-CDK4 complex, a possible critical factor for cell proliferation and prognosis in laryngeal squamous cell carcinomas

Cyclin D1 and its catalytic partner CDK4 are known to play important roles in the G1/S checkpoint of the cell cycle. The complex formed by CDK4 and cyclin D1 has been strongly implicated in the control of cell proliferation and prognoses in human malignancies. We investigated the immunohistochemical expression of cyclin D1, CDK4 and proliferating cell nuclear antigen (PCNA) in 102 patients with laryngeal squamous cell carcinoma (LSCC). Cyclin D1 overexpression was observed in 59 cases (57.8%) of LSCC, and was significantly correlated with tumor site, tumor size, lymph node metastasis and advanced stage. CDK4 overexpression was observed in 48 cases (47.1%), and was significantly correlated with tumor size and advanced stage. Cyclin D1 and CDK4 expression was significantly associated with cell proliferation measured by PCNA (r = 0.812, p < 0.0001 and r = 0.725, p < 0.0001, respectively). The Kaplan-Meier analysis showed that cyclin D1 overexpression was significantly associated with disease-free survival and overall survival. CDK4 overexpression was significantly associated with overall survival. When cyclin D1 and CDK4 are combined, the patients with co-overexpression of cyclin D1-CDK4 revealed the poorest overall survival. Additionally, in early-stage (I-II) cases, co-overexpression of cyclin D1-CDK4 was also revealed to possess a significant prognostic role. By multivariate analysis, cyclin D1 overexpression, lymph node metastasis and advanced stage were independent prognostic factors for disease-free survival. Cyclin D1 overexpression, CDK4 overexpression, tumor grade, lymph node metastasis and advanced stage were independent prognostic factors for overall survival. These findings indicate that cyclin D1 and CDK4 overexpression and/or co-overexpression of these proteins may play a pivotal role in the biological behavior of LSCC and may provide a strong prognostic implication.

Reliable, minimally invasive oromandibular reconstruction using metal plate rolled with pectoralis major myocutaneous flap

The purpose of this study was to minimize the surgical invasiveness to the donor site and the amount of the primary reconstruction time after oromandibular tumor resection. Oromandibular reconstruction was performed only using a pectoralis major myocutaneous flap and a metal plate. The pectoralis major myocutaneous flap was grafted to the oral cavity defect by rolling and wrapping around the metal plate with the muscle of the flap. No early postoperative complications have been noted in all seven patients. An average of 2 years and 1 month has past since surgery, and to date no infections, plate exposure, or plate breakage have been observed in any of the patients. The safety of the oromandibular reconstruction using a metal plate was improved by rolling the muscle of the pectoralis major myocutaneous flap around the metal plate. The present method was shown to be a rational technique that allowed primary reconstruction of the oral cavity and mandible in a minimally invasive manner in a short time.

Cyclin-dependent kinase inhibitor p27 is related to cell proliferation and prognosis in laryngeal squamous cell carcinomas

An immunohistochemical study of both p27 and proliferating cell nuclear antigen (PCNA) was performed on 102 cases of laryngeal squamous cell carcinomas (LSCCs), and large variations in p27 expression were found among the tumours. Reduced expression of p27 was revealed in 54 (52.9 per cent) cases and correlated with tumour size, lymph node metastasis, and clinical stage, but did not correlate with age, sex, tumour site, or tumour grade. A significant positive correlation was found between the percentage of loss of p27 expression and the PCNA index (r = 0.844, p < 0.0001). Reduced expression of p27 was significantly correlated with both reducing disease-free and overall survival by univariate analysis. By multivariate analysis, reduced expression of p27, tumour grade, tumour size, lymph node metastasis as well as clinical stage were independent prognostic factors for overall survival of LSCCs. These findings indicate that reduced expression of p27 may be correlated with the malignant biological behaviour of LSCCs.

Molecular cloning and characterization of a novel phospholemman-like protein from rat hippocampus

A cDNA encoding a putative ion channel protein was isolated from a rat hippocampus library. This gene, termed phosphohippolin (Php), contains 318 bp open reading frame encoding a single transmembrane protein with a 5' signal peptide region. The deduced amino acid sequence shares 48.1% homology with phospholemman (Plm). Expression sequence tag database (dEST) search identified a mouse (AA521976) and human (AA209241) Php gene homologues. The tissue distribution studies of Php mRNA showed its abundant expression in rat brain and kidney, and in the brain, high expression was observed in hippocampus and cerebellum.

Take percentage and conditions of cultured epithelium were improved when basement membrane of the graft was maintained and anchoring mesh was added

To achieve a higher take rate for epithelial grafts, this study investigated grafting techniques. Seventy-seven nude mice received flap grafting in which cultured human epithelium was grafted inside the flap, and 55 nude rats received transplantation of epithelium to a full-thickness skin defect. In each group, four models were studied, including model 1, in which epithelium was cultured with the conventional method; model 2, in which epithelium was cultured with fibrin gel to avoid sheet damage, then absorptive mesh was incorporated into the epithelium for anchoring to the graft bed; model 3, in which epithelium was cultured with fibrin gel and combined with absorptive mesh and artificial dermis containing fibroblasts; and model 4, in which the model 2 epithelium was grafted after artificial dermis was transplanted. The take for these models was evaluated grossly and histologically. The results show that the take percentage of models 2 and 3 was significantly higher than that of model 1 (conventional epithelium) and that there was no significant difference between model 3 (simultaneous grafting) and model 4 (two-step grafting). The difference in the take percentages of the grafts to the flap and to the full-thickness skin defect was also insignificant. In immunohistochemistry, human keratin appeared in all epidermis layers and diversification of the layer was observed in models 2, 3, and 4. In these three models, type IV collagen appeared in the basal layer and the formation of basal membrane was confirmed. These findings suggest that epithelia cultured on fibrin gel and combined with absorptive mesh could be used in a new technique for better, more stable take.

The overexpression of cyclin-dependent kinase (CDK) 2 in laryngeal squamous cell carcinomas

We examined the expression of CDK2 using immunohistochemistry in 102 cases of laryngeal squamous cell carcinomas (LSCCs). The results showed that a total of 63.73% (65/102) patients revealed a CDK2 overexpression pattern and the CDK2 overexpression was correlated significantly with the tumor site, tumor size and advanced stage. A positive correlation between the CDK2 expression and proliferative activity of tumor cells measured by proliferating cell nuclear antigen was found (r = 0.894, p < 0.0001). The Kaplan-Meier's analysis showed that shorter disease-free survival was significantly associated with tumor grade, tumor size, lymph node metastasis and advanced stage. Overall survival was significantly associated with tumor grade, tumor size, lymph node metastasis, advanced stage and CDK2 overexpression. When CDK2 and PCNA were combined, the patients with both CDK2 overexpression and PCNA overexpression had a poorer overall survival. We concluded that the CDK2 overexpression may be associated with the malignant biological behavior of LSCCs.

Enhanced expression and activation of Ca(2+)/calmodulin-dependent protein kinase IV in hepatocellular carcinoma

BACKGROUND

Ca(2+)/calmodulin-dependent protein kinase IV (CaM-kinase IV) is a multifunctional protein kinase that is expressed abundantly in the central nervous system and, to a lesser degree, in nonneuronal tissues such as the liver. In the current study, the authors demonstrated the expression of CaM-kinase IV in hepatocytes from hepatocellular carcinoma (HCC) in both humans and rats.

METHODS

Immunoblotting and immunohistochemical analysis were performed to confirm the expression of CaM-kinase IV and CaM-kinase kinase in HCC occurring in both humans and rats. The kinase activity of CaM-kinase IV in the lysate of each of these liver supernatant fluids was measured using a specific substrate (peptide gamma) for this enzyme before and after phosphorylation by exogenously added CaM-kinase kinase.

RESULTS

Marked positive staining of HCC hepatocytes was found and the subcellular staining pattern mainly was cytosolic. One immunoreactive band with a molecular weight of 64 kilodaltons, which was identical to an isoform of rat cerebellum CaM-kinase IV, was demonstrated by immunoblotting. Ca(2+)/calmodulin-dependent CaM-kinase IV activity was high in HCC and showed almost no difference in activity in specimens with and without CaM-kinase kinase phosphorylation.

CONCLUSIONS

CaM-kinase IV was found to be expressed in HCC and might have been involved in the development of HCC. CaM-kinase IV that was expressed in cancerous hepatocytes was phosphorylated mainly by CaM-kinase kinase that also was expressed in tumor cells.

Plasma-treated lenowoven polyethylene ribbon for bone fixation at dentoalveolar osteotomy

Plasma-treated lenowoven polyethylene ribbon was used for splinting between teeth around osteotomy lines in anterior segmental dentoalveolar osteotomy. This fixation was continued for 2 to 3 months, during which there was no damage or fall of the ribbon. In addition, the patients were able to eat their usual food, had much less pain in the teeth and oral mucosa, did not feel uncomfortable in the mouth, had no tooth damage or carious teeth, and had a good aesthetic appearance. In all eight jaws (five patients), accurate and strong bone fixation was achieved based on the planned occlusion. Patient complaints and pain were obviously less with this method than other methods. Polyethylene ribbon is quite useful for bone fixation in anterior segmental dentoalveolar osteotomy.

Inverse expression of Cdk4 and p16 in epithelial ovarian tumors

OBJECTIVES

The aim of this study was to elucidate the expression and the correlation of two cell cycle regulators, cdk4 and its inhibitor p16, in a series of benign, borderline, and malignant ovarian tumors and to evaluate whether their alterations correlate with clinicopathologial parameters and patients' prognosis in epithelial ovarian carcinomas.

METHODS

Immunohistochemical analysis using anti-cdk4 and anti-p16 antibodies was carried out for 103 paraffin sections of ovarian tumors, and Western blot analysis and cdk4 activity assay were performed in 26 fresh ovarian tumor samples.

RESULTS

The results of immunohistochemistry showed that 60.61 and 69.70% of benign, 69.57 and 56.52% of borderline, and 74.47 and 40. 43% of malignant tumors expressed cdk4 and p16, respectively, demonstrating increased cdk4 and decreased p16 expression in ovarian carcinomas. A significant inverse relationship between cdk4 and p16 expression was found. The loss of p16 expression was more correlated with G(2) and G(3) tumors in contrast with G(1) tumors. No significant correlation was observed between cdk4 expression and clinicopathological parameters. Neither cdk4 nor p16 expression has significant effects on overall survival by the Kaplan-Meier method. When the combined phenotypes of the two proteins were analyzed, patients with cdk4-positive/p16-negative expression had a reduced overall survival than other phenotypes of cdk4/p16.

CONCLUSIONS

These data suggest that inverse expression of cdk4 and p16 may be involved in the development and progression of epithelial ovarian carcinomas. The combined phenotypes of cdk4 and p16 proteins could provide a useful prognostic indicator for patients with epithelial ovarian carcinoma.