Anti-tumour effects of transcatheter arterial embolisation administered in combination with thalidomide in a rabbit VX2 liver tumour model

OBJECTIVE

Using a liver tumour model we investigated whether thalidomide enhances the anti-tumour effect of transcatheter arterial embolisation (TAE).

METHOD

First, the viability of VX2 tumour cells co-cultured with thalidomide in a 21% and 1% O(2) atmosphere was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Second, we randomly assigned 20 rabbits bearing VX2 liver tumours to 4 groups: Group 1 (thalidomide plus TAE), Group 2 (TAE only), Group 3 (thalidomide only) and Group 4 (control). Thalidomide was orally administered for 5 days. The anti-tumour effects were assessed by the tumour proliferation rate using MRI and by immunohistochemical analysis of the area of intratumoural vessels. Analysis of variance and Tukey's honestly significant difference test were used for statistical analysis.

RESULTS

The viability of cells grown under hypoxic and normal conditions was not significantly different, nor was there a difference among the four groups. The tumour size increased by 55.9±29.3% in Group 1, 250.6±73.3% in Group 2, 355.2±51.7% in Group 3 and 424.7±110.7% in Group 4; the difference between Group 1 and the other three groups was significant. The area of intratumour vessels in specimens was 0.22±0.28% in Group 1, 0.42±0.29% in Group 2, 1.44±1.00% in Group 3 and 6.00±2.17% in Group 4; the difference between Group 1 and the other groups was statistically significant, as was the difference between Groups 3 and 4.

CONCLUSION

Thalidomide used in combination with TAE enhanced anti-tumour effects in rabbits bearing VX2 liver tumours.

Comparison of the outcomes between anatomical resection and limited resection for single hepatocellular carcinomas no larger than 5 cm in diameter: a single-center study

BACKGROUND/PURPOSE

Liver resection is a widely preferred treatment modality for hepatocellular carcinomas (HCCs). This study aimed to compare the survival impact of anatomical resection with that of limited resection, in patients with single HCCs no larger than 5 cm in diameter.

METHODS

A cohort study was carried out on 209 consecutive patients who underwent hepatic resection for a single HCC no larger than 5 cm in diameter between January 1994 and March 2007 at Osaka City General Hospital.

RESULTS

The cumulative 5-year overall survival and disease-free survival rates in the anatomical resection group (n = 111) were 71 and 40%, respectively, both of which were significantly better than the 48 and 25% seen in the limited resection group (n = 98) (P = 0.0043 and P = 0.0232, respectively). Better effects of the anatomical resection on both overall and disease-free survival were seen in patients having HCC larger than 2 cm in diameter and in patients with moderately or poorly differentiated HCC. But no significant difference in either overall or disease-free survival was seen between the groups in patients with a HCC 2 cm or less in diameter or in the patients with well-differentiated HCC. Using Cox's regression model, anatomical resection was confirmed to be an independent favorable factor for both overall and disease-free survival.

CONCLUSIONS

Anatomical resection is therefore recommended for histologically advanced single HCCs ranging from 2 to 5 cm in diameter.

A combination of cisplatin-eluting gelatin microspheres and flavopiridol enhances anti-tumour effects in a rabbit VX2 liver tumour model

The aim of this study was to investigate whether the combination of cisplatin-eluting gelatin microspheres (GMSs) and flavopiridol enhances anti-tumour effects in a rabbit VX2 liver tumour model. Tumour-bearing rabbits (n = 21) were divided into five groups and infused from the proper hepatic artery. Group 1 (n = 5) received cisplatin-eluting GMSs (1 mg kg(-1)) and flavopiridol (3 mg kg(-1)), group 2 (n = 5) cisplatin-eluting GMSs alone (1 mg kg(-1)), Group 3 (n = 5) flavopiridol (3 mg kg(-1)), Group 4 (n = 3) GMSs alone (1 mg kg(-1)), and Group 5 (n = 3) was the control group receiving physiological saline (1 ml kg(-1)). On days 0 and 7 after procedures the liver tumour volume was measured using a horizontal open MRI system and the relative tumour volume growth rates for 7 days after treatment were calculated. On T(1) weighted images, the tumours were visualised as circular, low-intensity areas just below the liver surface. After treatment, the signals remained similar. The relative tumour volume growth rate for 7 days after treatment was 54.2+/-22.4% in Group 1, 134.1+/-40.1% in Group 2,166.7+/-48.1% in Group 3, 341.8+/-8.6% in Group 4 and 583.1+/-46.9% in Group 5; the growth rate was significantly lower in Group 1 than the other groups (p<0.05). We concluded that in our rabbit model of liver tumours the combination of cisplatin-eluting GMSs and flavopiridol was effective.

Expression of CD133, a possible marker for cancer stem cells (CSCs), in small cell lung cancer (SCLC) cell lines and non- small cell lung cancer (NSCLC) cell lines

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Background: Cancer stem cell (CSCs) are believed to play important roles in tumor development, recurrence or metastasis. Identification of CSCs may have a therapeutic significance. CD133 expression has been shown on a minority of various human cancer cells with high capability of self-renewal and proliferation. Therefore, CD133 is thought to be one of possible markers for CSCs. Regarding human lung cancers, the existence, prevalence or roles of CD133 positive cells has not been fully understood. Methods: We examined CD133 mRNA by quantitative real-time PCR and sorted CD133-positive cells by fluorescence-activated cell sorting (FACS) using human small cell lung cancer(SCLC) and non-small cell lung cancer (NSCLC) cell lines. We evaluated differences of cell proliferation between CD133-positive and -negative cells by MTS assay in vitro and by subcutaneous injection for non- obese diabetic/severe combined immunodeficiency (NOD/SCID) mice in vivo. Results: CD133 expression was almost restricted in SCLC cell lines. CD133 mRNA expression or CD133-positive cell population was scarcely observed in NSCLC cell lines. In two SCLC cell lines examined (NCI-H82 and NCI-H69), CD133 positive cells had higher tumorgenicity both in vivo and in vitro than NSCLC cell lines. Conclusions: The expression status of CD133 is totally different between NSCLCs and SCLCs, probably reflecting the difference of these progenitor cells. Our results indicate that CD133-positive cells in SCLC cell are responsible for tumor growth. However, in view of their wide prevalence, CD133-positive cells do not seem to be a candidate for CSCs, at least in cell lines. To investigate the molecular and functional characteristics of CD133-positive cells may lead to a new therapeutic strategy for human lung cancers, especially for SCLCs.

No significant financial relationships to disclose.

The effect of TAE226 on the non-small cell lung cancer including Japanese origin lung cancer

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Background: Mutations in the epidermal growth factor receptor (EGFR) gene is the predictive factor for sensitivity of EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer. Focal adhesion kinase (FAK) that is the downstream molecule of EGFR has been reported to be highly expressed in NSCLC suggesting novel therapeutic target of NSCLC. TAE226, dual inhibitor for FAK and insulin like growth factor-I receptor (IGF-IR), have been developed as anticancer reagent. In this study, we examined the effect of TAE226 on NSCLC from the view point of EGFR mutation status. Methods: We used NSCLC cell lines consisting of 4 EGFR mutant cell lines (PC9, H3255, HCC827, H1975) and 3 EGFR wild type cell lines (H1819, H1299, A549). We also used PC9 derived resistant cell line (RPC9). Antiproliferative effect of TAE226 on NSCLC cell lines was examined with MTS assay. The status of EGFR related molecules including its downstream signal pathway was investigated by western blotting analysis. The effect of TAE226 on xenograft mouse models was also examined. Results: TAE226 was effective on NSCLC cell lines with EGFR mutation including T790M mutation, compared to those with EGFR wild type. The value of IC50 (μmol/L) for PC-9, H3255, HCC827, H1975, RPC-9 and H1819, H1299, A549 was 0.16, 0.12, 0.086, 0.17, 0.31 and 4.7, 2.8, 1.4, respectively. Western blotting assay showed that TAE226 preferentially inhibited phosphor-EGFR and its downstream signaling mediators. We could confirm the anticancer effect of TAE226 on EGFR mutant cells was confirmed in xenograft mouse models. Conclusions: We indicated that TAE226 showed antitumor effect on EGFR mutant cell lines even T790M mutant cells. Further study is necessary to understand the mechanism of TAE226 effect on EGFR mutant cell lines. Our results suggest that TAE226 will be expected as the novel strategy for NSCLC.

No significant financial relationships to disclose.

Establishment and molecular characteristics of PC-9 derived erlotinib resistant cell lines

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Background: EGFR mutation is closely associated with tumor responsiveness to EGFR tyrosine kinase inhibitors (TKIs), gefitinib or erlotinib. However, many non-small cell lung cancer (NSCLC) cases with EGFR mutation that had responded to EGFR-TKIs finally acquire resistance to EGFR-TKIs. It has been reported that T790M mutation and MET amplification caused resistance to EGFR-TKIs . Recent study suggested that overexpression of HGF was also related to resistance to EGFR-TKIs. However, the whole mechanism of acquired resistance to TKIs is still not fully known. Methods: We established 5 clones of elrotinib resistant PC-9 cell line (harboring EGFR exon 19 deletion) (designated as PC-9ER1–5) by exposing PC-9 to low-dose erlotinib. The protein expression of EGFR-related molecules was examined by Western blotting. Array comparative genomic hybridization (aCGH) or real time quantitative PCR (qPCR) assay was performed to examine copy numbers of EGFR-related genes. Results: In MTS assay, the IC50 value for the parental PC-9 cells was 0.02 μmol/L. By contrast, those for PC-9ER1–5 were more than 33μmol/L. All 5 resistant cell lines retained exon19 deletions and did not obtain T790M mutation. The qPCR assay and aCGH showed no MET amplification in PC-9 or PC-9ER1–5. HGF protein was not overexpressed in PC-9ER1–5 by ELISA. The protein expressions of several molecules in the EGFR-Akt signaling pathway were examined by western blotting after erlotinib treatment. Although phospho-EGFR was suppressed in both PC-9 and PC-9ER1–5 with 2-μmol/L erlotinib, phospho-Akt was not suppressed in PC-9ER1–5. PTEN expression was not down-regulated in PC-9ER1–5. The combination of erlotinib and PHA-665752, MET tyrosine kinase inhibitor, did not suppress phospho-Akt or cell proliferation in PC-9ER1–5. Conclusions: As common molecular features of our EGFR-TKI resistant cell lines, phospho-Akt was not suppressed with exposure to erlotinib. These cell lines did not show previously reported features of resistant cell lines including T790M mutation, MET amplification or HGF overexpression. Our results indicated that other mechanisms leading to Akt activation caused resistance to EGFR-TKIs.

No significant financial relationships to disclose.

The antitumor effect of orally active heat shock protein 90 Inhibitor, 17-DMAG, on the growth of gefitinib-resistant non-small cell lung cancer

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Background: It has been reported that NSCLC cell lines with activating mutations of EGFRgene were significantly sensitive to Heat Shock Protein 90 (Hsp 90 ) ihibitors regardless of the secondary T790M mutation. Methods: We examined the antitumor effect of 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), the orally active Hsp90 inhibitor, on the growth of NSCLC cell lines in vitro and in vivo. Results: In MTS assay, the IC50 values for 3 cell lines with EGFR mutation (PC-9, RPC-9, and NCI-H1975) ranged from 0.15 to 0.28 μM. RPC-9 is a gefitinib-resistant lung cancer cell line with the secondary T790M mutation established from PC-9. By contrast, those of 7 EGFR-wild type cell lines ranged from 1.63 to 28.5 μM. Western blot analysis revealed that mutant EGFRs were more readily depleted than wild-type EGFRs after the treatment of 17-DMAG. Furthermore, expression of phospho-Akt, phospho-MAPK, cdk4, and cyclin D1 was depleted after exposure to low concentrations of 17-DMAG in EGFR-mutant cells. Celeaved PARP expression confirmed apoptosis in response to 17-DMAG in EGFR-mutant cells. In animal models, 17-DMAG significantly reduced the growth of EGFR-mutant cell lines PC-9 and RPC-9 compared with controls and induced degradation of mutant EGFR. In contrast, 17-DMAG did not inhibit the growth of EGFR wild type cell lines compared with controls. Conclusions: These results suggested that 17-DMAG could become a novel therapeutic agent for patients with lung tumors expressing mutant EGFR and having developed clinical resistance to gefitinib.

No significant financial relationships to disclose.

The jasmonate signaling pathway in tomato regulates susceptibility to a toxin-dependent necrotrophic pathogen

The plant hormone, jasmonic acid (JA), is known to have a critical role in both resistance and susceptibility against bacterial and fungal pathogen attack. However, little is known about the involvement of JA in the interactions between plants and toxigenic necrotrophic fungal pathogens. Using the tomato pathotype of Alternaria alternata (Aa) and its AAL-toxin/tomato interaction as a model system, we demonstrate a possible role for JA in susceptibility of plants against pathogens, which utilize host-specific toxins as virulence effectors. Disease development and in planta growth of the tomato pathotype of Aa were decreased in the def1 mutant, defective in biosynthesis of JA, compared with the wild-type (WT) cultivar. Exogenous methyl jasmonate (MeJA) application restored pathogen disease symptoms to the def1 mutant and led to increased disease in the WT. On the other hand, necrotic cell death was similarly induced by AAL-toxin both on def1 and WT, and MeJA application to the tomatoes did not affect the degree of cell death by the toxin. These results indicate that the JA-dependent signaling pathway is not involved in host basal defense responses against the tomato pathotype of Aa, but rather might affect pathogen acceptability via a toxin-independent manner. Data further suggest that JA has a promotional effect on susceptibility of tomato to toxigenic and necrotrophic pathogens, such that pathogens might utilize the JA signaling pathway for successful infection.

Alternaria brassicae produces a host-specific protein toxin from germinating spores on host leaves

Spore suspensions of Alternaria brassicae, the causal agent of gray leaf spot in Brassica plants, were incubated on the leaves of cabbage (B. oleracea) and spore germination fluid (SGF) was collected after 48 h. A high molecular weight (HMW) fraction (>10 kDa) was separated from the SGF by ultrafiltration. In a detached leaf assay, the HMW fraction induced visible symptoms only on host leaves and the toxicity was lost by treatment with proteinase K or heat at 60 degrees C for 15 min, indicating the presence of host-specific protein toxin(s). A protein toxin in the HMW fraction was purified by several chromatography steps. The toxin induced water-soaked symptoms followed by chlorosis at concentrations of 0.5 to 1 microg/ml on host leaves, but not on nonhost leaves even at 50 microg/ml. The toxin also had infection-inducing activity when added to spore suspension of a nonpathogenic isolate of A. alternata, causing symptoms similar to the infection of A. brassicae only on host leaves. These results indicate that a new host-specific protein toxin named ABR-toxin is released from germinating spores of A. brassicae on host leaves. ABR-toxin migrated as a protein of 27.5 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isoelectric point of ABR-toxin was estimated to be approximately 7.0 and 21 N-terminal amino acid residues were sequenced.

Partial functional overlap of the three ras genes in mouse embryonic development

In mammals, three ras genes, H-ras, N-ras and K-ras, encode homologous but distinct 21-kDa Ras proteins. We examined the in vivo functional relationship of the three ras genes in mouse embryonic development by investigating the phenotypes of mice deficient in one or multiple ras genes. H-ras-/- mice and N-ras-/- mice as well as a substantial proportion of H-ras-/-/N-ras-/- mice expressing only the K-ras gene were viable, while K-ras-/- mice were embryonically lethal, as have been reported previously. N-ras-/-/K-ras+/- mice died neonatally, while H-ras-/-/K-ras-/- embryos died much earlier than K-ras homozygous mutant fetuses. To further investigate the functional relationship of the ras genes in embryonic development, we introduced a human H-ras transgene into single or multiple ras mutant mice and found that the transgene rescued mice, including triple ras mutants, from embryonic lethality in association with correction of thin ventricular walls of the heart in null K-ras mutant mice. In situ hybridization revealed that the expression of the H-ras transgene on embryonic day E13.5 and E15.5 was more intense in major organs, including the heart, than those of endogenous ras genes. We therefore conclude that the functions of the ras genes are partially overlapping in mouse embryonic development.

Expression profiles of genes encoded by the supernumerary chromosome controlling AM-toxin biosynthesis and pathogenicity in the apple pathotype of Alternaria alternata

The apple pathotype of Alternaria alternata produces host-specific AM-toxin and causes Alternaria blotch of apple. Previously, we cloned two genes, AMT1 and AMT2, required for AM-toxin biosynthesis and found that these genes are encoded by small, supernumerary chromosomes of <1.8 Mb in the apple pathotype strains. Here, we performed expressed sequence tag analysis of the 1.4-Mb chromosome encoding AMT genes in strain IFO8984. A cDNA library was constructed using RNA from AM-toxin-producing cultures. A total of 40,980 clones were screened with the 1.4-Mb chromosome probe, and 196 clones encoded by the chromosome were isolated. Sequence analyses of these clones identified 80 unigenes, including AMT1 and AMT2, and revealed that the functions of 43 (54%) genes are unknown. The expression levels of the 80 genes in AM-toxin-producing and nonproducing cultures were analyzed by real-time quantitative polymerase chain reaction (PCR). Most of the genes were found to be expressed in both cultures at markedly lower levels than the translation elongation factor 1-alpha gene used as an internal control. Comparison of the expression levels of these genes between two cultures showed that 21 genes, including AMT1 and AMT2, were upregulated (>10-fold) in AM-toxin-producing cultures. Two of the upregulated genes were newly identified to be involved in AM-toxin biosynthesis by the gene disruption experiments and were named AMT3 and AMT4. Thus, the genes upregulated in AM-toxin-producing cultures contain ideal candidates for novel AM-toxin biosynthetic genes.

Life-style activities in systemic lupus erythematosus

OBJECTIVE

We evaluated the life-style activities of outpatients with SLE and factors that reduce their social activities.

METHODS

SUBJECTS

SLE group = 60 patients, Control 1 = 30 healthy subjects and Control 2 = 30 patients with other autoimmune diseases. The Frenchay Activity Index (FAI), Zung's self-rating depression scale (SDS), and the Japanese version of the Philadelphia Geriatric Center morale scale-revised (MS) were compared between groups. Relation between FAI and age, disease duration, steroid dose, SDS, and MS were examined in the SLE group, Control 1, and Control 2.

RESULTS

Total scores by FAI was 28.1 +/-8.0 points in Control 1, whereas it was 26.5 +/- 5.8 points in Control 2 and 24.5 +/- 7.7 points in the SLE group. While there was no statistical difference between the SLE group and Control 2, the scores were significantly lower in the SLE group than in Control 1 (P < 0.05). In SLE patients, age, the duration of the disease, and the steroid dose had no correlation, but MS had a positive correlation (P < 0.05) and SDS had a negative correlation (P < 0.05). In Control 2, age, the duration of the disease, the steroid dose, MS and SDS had no correlation whereas there was significant negative relation between FAI and SDS in Control 1 (r= -0.516, P<0.005).

CONCLUSION

The significant relation between life-style activities and subjective well-being, and depression in SLE suggests that detection and treatment of mental status is important in improving the life-style activities of SLE patients.

G protein signaling mediates developmental processes and pathogenesis of Alternaria alternata

A G protein alpha subunit gene (AGA1) has been cloned and characterized from a toxigenic and necrotrophic Alternaria alternata pathogen. Targeted disruption of AGA1 in the apple pathotype of A. alternata gave rise to mutants that differed in colony and conidial morphology as well as sporulation. The conidia of wild type and deltaAGA1 mutants showed equal germination on cellulose membranes. However, wild-type germ tubes formed readily from different points around the conidia, grew randomly, and were often branched, whereas those of the mutants formed only at one or both ends of the conidia and tended to grow in straight paths. Targeted disruption of AGA1 also resulted in reduction of pathogenicity on apple leaves, although the mutant produced host-specific AM-toxin, a fungal secondary metabolite associated with pathogenicity of the pathogen, at levels similar to the wild-type strain. Measurement of the intracellular cAMP levels of the mutant revealed that it was consistently higher than that of the wild type, indicating that AGA1 negatively regulates cAMP levels similar to mammalian Galphai systems. These results indicate that the signal transduction pathway represented by AGA1 appears to be involved in developmental pathways leading to sporulation and pathogenesis of A. alternata.

Reg I-knockout mice reveal its role in regulation of cell growth that is required in generation and maintenance of the villous structure of small intestine

Reg I (regenerating gene product I) is a growth factor that plays a central role in the generation and regeneration of the gastric mucosal architecture. On the other hand, mouse Reg I mRNA is expressed at the highest levels in the small intestine among the gastrointestinal tissues. In the current study, with the aim to clarify the role of Reg I protein in the small intestine, the temporal and spatial pattern of Reg I expression and the phenotype of Reg I-knockout mice in the tissue were examined. In the wild-type mice, immunohistochemistry localized Reg I protein expression in absorptive cells located in the lower half of the intestinal villi. Reg I expression was undetectable until embryonic day 13 (E13), when the fetal intestine still lacks villous structure; however, it dramatically increased at E17 along with the formation and maturation of the fetal intestinal villi. In the small intestine of the adult Reg I-knockout mice, less densely packed, round-shaped aberrant morphology of the absorptive cells was observed light microscopically, and electron microscopical examination revealed a strikingly loose connection of these cells to the basement membrane. Antiproliferating cell nuclear antigen staining and anti-Ki67 staining demonstrated the marked decrease in the number of proliferating cells in the small intestinal mucosa of the knockout mice. The cell migration speed visualized by one shot labeling of 5-bromodeoxyuridine was significantly slower in the knockout mice. These phenotypes of Reg I-knockout mice emerged, in accordance with the temporal pattern of Reg I expression described above, from E17. Reg I was considered to be a regulator of cell growth that is required to generate and maintain the villous structure of the small intestine.

Temporal effects of edaravone, a free radical scavenger, on transient ischemia-induced neuronal dysfunction in the rat hippocampus

We examined the effect of a free radical scavenger edaravone on ischemia/reperfusion-induced impairment of long-term potentiation in the perforant path-dentate gyrus synapses of the rat hippocampus, as a measure of functional outcome 4 days after transient global ischemia (2-vessel occlusion, 10 min). Edaravone (3 and 10 mg/kg, i.v.) immediately after reperfusion (Day 0) alleviated ischemia-induced impairment of long-term potentiation in a dose-related manner, whereas treatment on Day 1 or 4 after reperfusion failed to rescue the impaired long-term potentiation. Edaravone administration on Day 0 also prevented the post-ischemic increase in hydroxyl radical formation and the expression of vascular endothelial growth factor, basic fibroblast growth factor and neuronal and inducible nitric oxide synthases of the hippocampus. Thus, edaravone protected the rat hippocampus from ischemia-induced long-term potentiation impairment with a therapeutic time window, suggesting that free radical formation after ischemia/reperfusion is a pivotal trigger of neurofunctional complications after global ischemic stroke.

Fetal jaw movement affects condylar cartilage development

Using a mouse exo utero system to examine the effects of fetal jaw movement on the development of condylar cartilage, we assessed the effects of restraint of the animals' mouths from opening, by suture, at embryonic day (E)15.5. We hypothesized that pre-natal jaw movement is an important mechanical factor in endochondral bone formation of the mandibular condyle. Condylar cartilage was reduced in size, and the bone-cartilage margin was ill-defined in the sutured group at E18.5. Volume, total number of cells, and number of 5-bromo-2'-deoxyuridine-positive cells in the mesenchymal zone were lower in the sutured group than in the non-sutured group at E16.5 and E18.5. Hypertrophic chondrocytes were larger, whereas fewer apoptotic chondrocytes and osteoclasts were observed in the hypertrophic zone in the sutured group at E18.5. Analysis of our data revealed that restricted fetal TMJ movement influences the process of endochondral bone formation of condylar cartilage.