Interleukin-17 exacerbates hepatic steatosis and inflammation in non-alcoholic fatty liver disease

Mechanisms associated with the progression of simple steatosis to non-alcoholic fatty liver disease (NAFLD) remain undefined. Regulatory T cells (T(regs)) play a critical role in regulating inflammatory processes in non-alcoholic steatohepatitis (NASH) and because T helper type 17 (Th17) functionally oppose T(reg)-mediated responses, this study focused on characterizing the role of Th17 cells using a NAFLD mouse model. C57BL/6 mice were fed either a normal diet (ND) or high fat (HF) diet for 8 weeks. Mice in the HF group had a significantly higher frequency of liver Th17 cells compared to ND-fed mice. Neutralization of interleukin (IL)-17 in HF mice ameliorated lipopolysaccharide (LPS)-induced liver injury reflected by decreased serum alanine aminotransferase (ALT) levels and reduced inflammatory cell infiltrates in the liver. In vitro, HepG2 cells cultured in the presence of free fatty acids (FFA; oleic acid and palmitic acid) for 24 h and IL-17 developed steatosis via insulin-signalling pathway interference. IL-17 and FFAs synergized to induce IL-6 production by HepG2 cells and murine primary hepatocytes which, in combination with transforming growth factor (TGF-β), expanded Th17 cells. It is likely that a similar process occurs in NASH patients, as there were significant levels of IL-17(+) cell infiltrates in NASH patient livers. The hepatic expression of Th17 cell-related genes [retinoid-related orphan receptor gamma (ROR)γt, IL-17, IL-21 and IL-23] was also increased significantly in NASH patients compared to healthy controls. Th17 cells and IL-17 were associated with hepatic steatosis and proinflammatory response in NAFLD and facilitated the transition from simple steatosis to steatohepatitis. Strategies designed to alter the balance between Th17 cells and T(regs) should be explored as a means of preventing progression to NASH and advanced liver diseases in NAFLD patients.

Expression of the stem cell marker nestin in pre/hypertrophic chondrocytes in osteochondroma

The pathogenesis of osteochondroma, the most common benign bone tumour, is not fully known. To date, regulation of nestin protein levels in osteochondromas and normal growth plates has not been reported. This study used immunohistochemical analysis to detect nestin protein levels in 48 osteochondromas and 13 normal growth plates (eight fetal and five postnatal). Nestin protein was mainly restricted to prehypertrophic and hypertrophic chondrocytes in osteochondroma. Nestin levels were significantly higher in osteochondromas in adolescents (age range 4 - 18 years, n = 32) than in osteochondromas in young adults (age range 20 - 28 years, n = 11), and significantly higher in osteochondromas in young adults than in those in older adults (age range 40 - 77 years; n = 5). Nestin protein was not present in normal growth plates. The presence of nestin protein parallels the biological behaviour of osteochondromas and is restricted to prehypertrophic and hypertrophic chondrocytes, indicating that these nestin-positive cells may be central to osteochondroma development.

Pharmacogenetics of the mycophenolic acid targets inosine monophosphate dehydrogenases IMPDH1 and IMPDH2: gene sequence variation and functional genomics

BACKGROUND AND PURPOSE

Inosine monophosphate dehydrogenases, encoded by IMPDH1 and IMPDH2, are targets for the important immunosuppressive drug, mycophenolic acid (MPA). Variation in MPA response may result, in part, from genetic variation in IMPDH1 and IMPDH2.

EXPERIMENTAL APPROACH

We resequenced IMPDH1 and IMPDH2 using DNA from 288 individuals from three ethnic groups and performed functional genomic studies of the sequence variants observed.

KEY RESULTS

We identified 73 single nucleotide polymorphisms (SNPs) in IMPDH1, 59 novel, and 25 SNPs, 24 novel, in IMPDH2. One novel IMPDH1 allozyme (Leu275) had 10.2% of the wild-type activity as a result of accelerated protein degradation. Decreased activity of the previously reported IMPDH2 Phe263 allozyme was primarily due to decreased protein quantity, also with accelerated degradation. These observations with regard to the functional implications of variant allozymes were supported by the IMPDH1 and IMPDH2 X-ray crystal structures. A novel IMPDH2 intron 1 SNP, G > C IVS1(93), was associated with decreased mRNA quantity, possibly because of altered transcription.

CONCLUSIONS AND IMPLICATIONS

These results provide insight into the nature and extent of sequence variation in the IMPDH1 and IMPDH2 genes. They also describe the influence of gene sequence variation that alters the encoded amino acids on IMPDH function and provide a foundation for future translational studies designed to correlate sequence variation in these genes with outcomes in patients treated with MPA.

Wolbachia screening in spiders and assessment of horizontal transmission between predator and prey

Recent studies have revealed that the prevalence of Wolbachia in arthropods is attributable not only to its vertical transmission, but also to its horizontal transfer. In order to assess the horizontal transmission of Wolbachia between predator and prey, arthropods belonging to 11 spider families and six insect families were collected in the same field of rice. The distribution of Wolbachia in these arthropods was detected by diagnostic PCR amplification of the wsp (Wolbachia outer surface protein gene) and 16S rDNA genes. Nurscia albofasciata Strand (Araneae: Titanoecidae), Propylea japonica Thunberg (Coleoptera: Coccinellidae), Paederus fuscipes Curtis (Coleoptera: Staphylinidae), and Nilaparvata lugens Stal (Homoptera: Delphacidae) were infected with Wolbachia. This is the first report of infection of N. albofasciata and P. fuscipes by Wolbachia. No direct evidence indicated the existence of horizontal transmission of Wolbachia between predator and prey.

Orf virus ORFV121 encodes a novel inhibitor of NF-kappaB that contributes to virus virulence

Orf virus (ORFV), the type member of the genus Parapoxvirus of the Poxviridae, has evolved novel strategies (proteins and/or mechanisms of action) to modulate host cell responses regulated by the nuclear factor-κB (NF-κB) signaling pathway. Here, we present data indicating that ORFV ORFV121, a gene unique to parapoxviruses, encodes a novel viral NF-κB inhibitor that binds to and inhibits the phosphorylation and nuclear translocation of NF-κB-p65. The infection of cells with an ORFV121 deletion mutant virus (OV-IA82Δ121) resulted in increased NF-κB-mediated gene transcription, and the expression of ORFV121 in cell cultures significantly suppressed NF-κB-regulated reporter gene expression. ORFV ORFV121 physically interacts with NF-κB-p65 in the cell cytoplasm, thus providing a mechanism for the inhibition of NF-κB-p65 phosphorylation and nuclear translocation. Notably, the deletion of ORFV121 from the viral genome markedly decreased ORFV virulence and disease pathogenesis in sheep, indicating that ORFV121 is a virulence determinant for ORFV in the natural host.

Spirobisnaphthalenes from fungi and their biological activities

Spirobisnaphthalenes have a unique structural feature involving two or three oxygen atoms acting as bridges connecting two original naphthalene subunits. Most of these metabolites isolated from fungi exhibit significant antifungal, antibacterial and cytotoxic properties to show great potential applications in medicine and agriculture. This review focuses on their structural characters and biological activities, as well as their structure-activity relationship, mechanism of action, synthesis and biosynthesis.

S-1 and intraperitoneal and intravenous paclitaxel as neoadjuvant chemotherapy for gastric cancer with positive peritoneal cytology

142

Background: The prognosis of gastric cancer with positive peritoneal cytology is dismal. Standard treatments for these patients have not been established. The purpose of this study was to evaluate the safety and response of the regimen.

Methods: Patients who were diagnosed with advanced gastric cancer between 2007 and 2010 underwent staging laparoscopy and received intraperitoneal paclitaxel when peritoneal cytology were positive and sequential systemic chemotherapy, S-1 combined with intravenous paclitaxel within 14 days after staging laparoscopy. Paclitaxel was administered intraperitoneally at 80 mg/m2. S-1 was administered at 80 mg/m2/day for 14 consecutive days, followed by 7 days rest. Paclitaxel was administered intravenously at 50 mg/m2 on day 1 and day 8. After 2 courses of S-1 combined with paclitaxel were administered, clinical response was assessed by gastroendoscopy and computed tomography. Additional 2 or 3 courses were administered unless progression of disease was proved. Patients who achieved complete response (CR) or partial response (PR) and patients with stable disease (SD) underwent second-look laparoscopy following gastrectomy when peritoneal cytology turned negative.

Results: 8 (7 male, 1 female) patients were enrolled: median age was 64 years (range 40-75). Of 8 patients, 1 patient achieved CR, and 5 PR. 2 patients showed progressive disease (PD). Grade 3 neutropenia occurred in 1 patient. 6 patients underwent second-look laparoscopy and peritoneal cytology turned negative in all 6 patients. Total or distal gastrectomy with lymphnode dissection was performed consecutively in 3 or 3 patients, respectively. Median follow-up duration was 775 days (range 187-1,028). No recurrence has not been observed, while the 1-year and 2-year survival rates of 14 patients with peritoneal cytology positive gastric cancer who have not received neoadjuvant chemotherapy were 58.3% and 33.3%, respectively.

Conclusions: S-1, intraperitoneal and intravenous paclitaxel as neoadjuvant chemotherapy seems to be a effective strategy against gastric cancer with positive peritoneal cytology.

No significant financial relationships to disclose.

A nuclear inhibitor of NF-kappaB encoded by a poxvirus

Poxviruses have evolved various strategies to inhibit cytoplasmic events leading to activation of the nuclear factor κB (NF-κB) signaling pathway, with individual viruses often encoding multiple NF-κB inhibitors. Here, the novel orf virus (ORFV)-encoded protein ORFV002 was shown to inhibit nuclear events regulating NF-κB transcriptional activity. ORFV002 expression in cell cultures significantly decreased wild-type-virus-, tumor necrosis factor alpha (TNF-α)-, and lipopolysaccharide (LPS)-induced NF-κB-mediated gene expression. Expression of ORFV002 in cells, while not affecting phosphorylation or nuclear translocation of NF-κB-p65, markedly decreased TNF-α- and wild-type-virus-induced acetylation of NF-κB-p65, a p300-mediated nuclear modification of NF-κB-p65 that regulates its transactivating activity. ORFV002 was shown to colocalize and interact with NF-κB-p65, and expression of ORFV002 in cell cultures resulted in a reduced interaction of NF-κB-p65 with p300, suggesting that ORFV002 interferes with NF-κB-p65/p300 association. Deletion of ORFV002 from the OV-IA82 genome had no significant effect on ORFV pathogenesis in sheep, indicating that ORFV002 is nonessential for virus virulence in the natural host. This represents the first description of a nuclear inhibitor of NF-κB encoded by a poxvirus.

Melting of multilayer colloidal crystals confined between two walls

Video microscopy is employed to study the melting behaviors of multilayer colloidal crystals composed of diameter-tunable microgel spheres confined between two walls. We systematically explore film thickness effects on the melting process and on the phase behaviors of single crystal and polycrystalline films. Thick films (>4 layers) are observed to melt heterogeneously, while thin films (≤4 layers) melt homogeneously, even for polycrystalline films. Grain-boundary melting dominates other types of melting processes in polycrystalline films thicker than 12 layers. The heterogeneous melting from dislocations is found to coexist with grain-boundary melting in films between 5- and 12-layers. In dislocation melting, liquid nucleates at dislocations and forms lakelike domains embedded in the larger crystalline matrix; the "lakes" are observed to diffuse, interact, merge with each other, and eventually merge with large strips of liquid melted from grain boundaries. Thin film melting is qualitatively different: thin films homogeneously melt by generating many small defects which need not nucleate at grain boundaries or dislocations. For three- and four-layer thin films, different layers are observed to have the same melting point, but surface layers melt faster than bulk layers. Within our resolution, two- to four-layer films appear to melt in one step, while monolayers melt in two steps with an intermediate hexatic phase.

Abstract P4-08-07: Correlation of Oncotype Dx Recurrence Score and Luminal Subtypes of Breast Cancer

Background: Molecular subtypes of breast cancer have been characterized by gene expression analysis. Luminal subtypes are hormone receptor (HR) positive and Her2/neu negative. Immunohistochemistry (IHC) has been used as a surrogate test for gene expression. Ki67 is a proliferation marker that identifies high-risk subtype of luminal breast cancer. Recently, the proposed Ki67 index (KI) of 14% was suggested as a cut-off to distinguish between luminal A and luminal B tumors (JNCI. 2009;101:736-750). The oncotype dx (ODx) is a 21- gene test that provides prognostic and predictive information in early stage HR-positive breast cancer patients. The test is reported as low (<18), intermediate (18-30) and high (>30) risk recurrence scores (RS)

Design: We investigated the relationship between ODx RS and luminal subtypes of breast cancers using the KI of 14% as the cut-off for distinguishing luminal A and B tumors. Biomarker analysis (ER, PR, Her2/neu, Ki67 and p53) was performed as part of the diagnostic work-up using standard IHC procedures. Scoring was done by automated image analysis. Her2/neu FISH was performed on all IHC 2+ and 3 + results.

Pathologic parameters such as, tumor size, grade, and presence of LVI were evaluated. Ploidy was performed by the Autocyte system (Tripath) on Feulgen stained paraffin sections.

Results: We identified 106 patients with HR positive breast cancer who were tested for ODx from February 2006 to May 2010. 85/106 had Ki67 data available for analysis. 46/85 (54%) were luminal A and 39/85 (46%) luminal B tumors. The mean KI in luminal A was 6.93% versus 31.1% in luminal B (P<0.0001). The mean tumor size was 1.94 and 1.92 cm in luminal A and B respectively. Grade 1, 2 and 3 comprised 28/85 (32.9%), 49 (57.6%) and 8 (9.41%) of all tumors respectively. Of the grade1 tumors, 75% were luminal A, and grade 3 tumors were predominantly luminal B (p=0.013). LVI was present in 16 cases, 11 (68.8%) in luminal B and 5/16 (31.2%) in luminal A tumors (p=0.0416). Luminal A tumors were predominantly diploid 30/45 (66.6%) and luminal B were mostly aneuploid 21/32 (65.6%) (p=0.019). The overall mean RS in luminal A and B tumors was 14.67 and 20.15 respectively (P<0.0004). Luminal A tumors had low RS in 32/46 (66.6%). and luminal B tumors had predominantly intermediate/high RS in 23/39 (62.1%) (p=0.0082). ER Allred Scores were 7.1 and 7.3 and percent positivity was 88.1% and 91% respectively for luminal A and B subtypes. PR Allred scores were 5.6 and 5.8, and percent positivity was 62.1 and 52.9% for A and B tumors respectively. Information regarding treatment was available in 72 cases. 19 (26.3%) were treated by a combination of chemo and anti-hormonal therapy and 53 (73.6%) were treated by anti hormonal therapy alone, 8 of the 19 (42.1%) luminal A patients received combination therapy versus 11 (57.8%) in the luminal B category (p=0.277).

Conclusion: Ki67 is a useful marker that showed significant correlation with RS by ODx. Luminal A tumors are more likely to be low grade, diploid with low RS compared to luminal B tumors. Ki67 in conjunction with other pathologic parameters may serve as a surrogate marker for the ODx RS.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-08-07.

Abstract P4-08-10: Correlation of Oncotype Dx Recurrence Score with Histologic Parameters, Biomarker Expression and KI-67 Index

Background: Oncotype Dx (ODx) is a 21-gene RT-PCR based assay that provides prognostic and predictive information in patients with hormone receptor (HR) positive breast cancer. The test predicts the likelihood of disease recurrence in the form of a recurrence score (RS), which is categorized into low, intermediate and high-risk types. We examined the relationship between ODx RS and histologic parameters, DNA ploidy, tumor markers (ER, PR, Her2, Ki67, p53) expression by immunohistochemistry (IHC).

Design: We identified 106 patients with HR-positive invasive breast cancer who were tested for ODx from the department files. Pathologic variables such as, tumor size, grade, histologic type, lymphovascular invasion (LVI) were reviewed. Tumor markers ER, PR, Her2, p53 expression, Ki67 index (KI) and ploidy were performed as part of the patient's diagnostic work-up using standard procedures. Scoring was done by automated image analysis. Results of biomarker expression were compared to the ODx RS. All Her2neu 3+ and 2+ results by IHC were confirmed by FISH. Ploidy was performed by the Autocyte system (Tripath) on Feulgen stained sections. Oncotype RS was reported as low (<18), intermediate (18-30) and high risk (>30).

Results: Mean tumor size was 1.96 cm. Of the 106 cases, 87 (82%), 14 (13.2%) and 2(1.8%) were ductal, lobular and mixed types respectively. Grade 1, 2 and 3 comprised 35 (33.0%), 62 (58.4%) and 9 (8.5%) respectively. Twenty-one (19.8%) had LVI. Oncotype RS was low in 56 (52.8%), intermediate in 45 (42.4%) and high in 5 (4.7%). Mean tumor size in low RS group was 2.2 cm versus 1.6 cm in the intermediate/high RS group (p <0.05). There was no significant association of grade and LVI with RS. ER Allred score was 7.2, 7.2 and 8.0 and percent positivity was 88.0%, 91.1% and 96.3% in low, intermediate and high RS respectively (p=0.6325). The PR Allred score was 6.0, 5.3 and 3.5 and percent positivity was 64.7%, 51.8% and 16.6% in low, intermediate and high RS respectively (p=0.0432). There was 100% concordance between ER by IHC and ODx. Concordance for PR was 71/75 (94.6%). The four discordant PR results by ODx had mean score of 20% by IHC. The mean KI was 14.4%, 21.8% and 25.6% in low, intermediate and high RS respectively (p=0.0248). Low KI (<14%) and high KI (>14%) showed significant correlation with RS (p=0.0055). Her2neu IHC was negative in 43/49 (87.7%) and borderline in 6/49 (12.2%) and all were negative by FISH. Her2 FISH showed 100% (44/44) concordance with Her2 results by ODx. There was no association between DNA ploidy and RS (p=0.7143). P53 expression showed no significant correlation with RS (p=0.2602). Patients in the intermediate/high RS group were more likely to be treated with a combination of chemo plus anti-hormonal therapy (P<0.0001) and radiation (P<0.05) compared to the low RS group.

Conclusions: This study shows a complete concordance between ER IHC and Her2 FISH with RT-PCR by ODx. Low PR scores and high KI predict

high RS by ODx. There is a significant association between KI and ODx RS. Ki67 index identifies low and high RS groups, which correspond to the luminal A, and B subtypes of breast cancer respectively.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-08-10.