Elevation of plasma interleukin-18 concentration is associated with insulin levels in patients with systemic lupus erythematosus

We previously reported that systemic lupus erythematosus (SLE) patients have a higher risk of insulin resistance and abnormal insulin secretion. Recent studies demonstrated that interleukin (IL)-18, a novel pro-inflammatory cytokine, may be involved in triggering the inflammatory processes in SLE and the concentrations of circulating IL-18 in SLE patients were significantly higher than those in healthy subjects. IL-12 has a synergistic effect with IL-18, and both cytokines are inducers of interferon γ. The objective of this study was to identify the effect of fasting insulin levels on circulating concentrations of IL-18, IL-12 and IFN-γ in patients with SLE. Plasma levels of proinflammatory Th-1 cytokines were determined by enzyme-linked immunosorbent assay in a total of 70 female SLE patients and 34 age-matched healthy females. Insulin resistance (IR) and secretion were evaluated by homeostasis model assessment (HOMA). All patients were further classified into subgroups based on the quartiles of fasting insulin levels. SLE patients with fasting insulin levels in the top quartile compared with other quartiles had significantly higher plasma levels of IL-18. The presence of insulin auto-antibodies (IAA) in SLE patients had no influence on plasma levels of IL-18. In addition, fasting insulin levels and HOMA IR were positively correlated with IL-18 in all SLE patients, respectively. In conclusion, elevated circulating IL-18 concentrations corresponded with increases in fasting insulin levels and the status of insulin resistance in patients with SLE.

Association of brachial-ankle pulse wave velocity with cardiovascular risk factors in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is associated with premature atherosclerosis. Increasing arterial stiffness is closely associated with atherosclerotic cardiovascular diseases, and pulse wave velocity (PWV) is considered to be an indicator of arterial stiffness. The objective of this study was to identify the relationship between brachial-ankle pulse wave velocity (baPWV) and cardiovascular risk factors in patients with SLE. Age, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBS), plasma lipid profile, plasma homocysteine, thiobarbituric acid reactive substances (TBARS), baPWV, ankle-brachial index (ABI), and SLE-related factors were determined in a total of 83 SLE patients (12 males and 71 females). All SLE patients were further classified into two subgroups according to baPWV value (baPWV 1400 cm/s, n 37 versus baPWV 1400 cm/s, n 46). The mean baPWV value of studied SLE patients was 1520 381 cm/s. Age, BMI, SBP, DBP, FBS, TBARS and homocysteine levels were significantly higher in SLE patients with baPWV value 1400 cm/s than in SLE patients with baPWV value 1400 cm/s. In addition, baPWV correlated significantly with age, SBP, DBP, FBS and homocysteine. Moreover, stepwise multiple regression analysis showed that age and SBP were independently associated with baPWV. The results of this study indicate a possible link between vascular stiffness measured by baPWV and cardiovascular risk factors in patients with SLE.

Increased expression of SKP2 is an independent predictor of locoregional recurrence in cervical cancer via promoting DNA-damage response after irradiation

Although radiation therapy was known to be effective to cervical cancer, loco-regional recurrences are frequently found in patients. We aimed to identify a molecular marker predicting the response of cervical cancer to radiotherapy. We included the patients (n = 149) with cervical cancer who had undergone radiotherapy from 2004 to 2006. Tumor samples were collected to examine the association between the expression of S-phase kinase-associated protein 2 (SKP2) and prognosis in cervical cancer. We found higher expression of SKP2 associated with recurrence (HRs: 2.52, p < 0.001), death (HRs: 2.01, p < 0.001) and higher locoregional recurrence rate (HRs: 3.76, p < 0.001). Cervical cancer cell lines with higher expression of SKP2 showed higher colony formation, cell survival rate and fewer DNA damages after irradiation. SKP2-C25, an inhibitor for SKP2 activity, dose-dependently decreased cell viability after irradiation and knockdown of SKP2 impaired DNA-damage response and sensitized the cervical cancer cells to irradiation. Our data showed the SKP2 represents a promising tool to identify patients with cervical cancer who have a higher risk of locoregional recurrence after radiotherapy. Targeting SKP2 may serve as a potential radiosensitizer for developing effective therapeutic strategies against cervical cancer.

[Metabolic syndrome and its influencing factors in professional automobile drivers in a company]

OBJECTIVE

To investigate the prevalence of metabolic syndrome (MS)in 259 professional automobile drivers, and to put forward targeted suggestions on protection.

METHODS

In October 2014, 114 male bus drivers and 145 male taxi drivers in a transportation service company were enrolled as investigation group, and 121 non-operating male staff were enrolled as control group. Physical examination and a questionnaire survey were conducted for both groups, and the results were analyzed.

RESULTS

The bus drivers and taxi drivers had significantly higher prevalence rates of MS than the nonoperating staff(17.5%/13.1% vs 3.3%, P<0.05). The results of univariate logistic analysis showed that smoking(OR=2.58, 95%CI 1.14~5.88), exercise (OR=0.21, 95% CI 0.10~0.43), meal time (OR=0.27, 95% CI 0.13~0.59), and a family history of chronic diseases (OR=2.26, 95% CI 1.13~4.50)were associated with MS, and each independent variable showed significant differences between groups (P<0.05). Multivariate logistic regression analysis showed that with age remaining the same, smoking was the risk factor for MS in professional automobile drivers (OR=5.25, 95%CI 2.00~13.80), and meal time (20~40 min)(OR= 0.20, 95%CI 0.09~0.44)and exercise (OR=0.13, 95% CI 0.06~0.30)were protective factors against MS.

CONCLUSION

Professional automobile drivers have a higher prevalence rate of MS than non-operating staff, which should be taken seriously by working personnel.

[Comparison between poly hydroxy acrylic acid and Van-clear replacing the traditional reagents to detect the cervical hTERC genes by adopting FISH technique]

OBJECTIVE

To observe the difference of the human telomeres RNA component (hTERC) genes' amplification in the cervical tissue by applying the environment-friendly fixative poly hydroxy acrylic acid and the transparent dewaxing solution Van-clear separately or jointly to replace the traditional fixative 4% (volume fraction) neutral buffered formalin and the conventional transparent dewaxing solution xylene in the use of fluorescence in situ hybridization (FISH) for detection.

METHODS

In the study, 255 cases of cervical tissue specimens submitted by the Department of Gynecology in Zhongshan Boai Hosipital were collected from Mar. 2013 to Apr. 2015. Four samples were taken from the same lesion site. All the cases were divided into 4 groups and named group A, B, C, and D. Group A used 4% neutral buffered formalin fixed and xylene dewaxing to make slices. Group B used poly hydroxy acrylic fixed and xylene dewaxing to make slices. Group C used 4% neutral buffered formalin fixed and Van-clear transparent to make slices. Group D used poly hydroxy acrylic fixed and Van-clear transparent dewaxing to make slices. The amplification of hTERC genes in the four groups of cervical specimens was also detected by FISH technique.

RESULTS

When the hTERC genes were detected by FISH method under the fluorescence microscope, it was obvious that the tissue profile and the background of group A, B, C and D were all clear. The probe was fixed in the accurate position so that the bright red or green fluorescence signals were easily found in these four groups. Compared with the positive rate of group A, there was no statistical significance in that of group B, C and D (P>0.05). At the same time, the coincidence rate of the FISH results was high, which showed that the new environment-friendly reagent had no significant difference in the detection of cervical hTERC genes by FISH technique.

CONCLUSION

It is possible for the environment-friendly reagent poly hydroxy acrylic acid and Van-clear to replace 4% neutral buffered formalin and xylene separately or jointly to detect the cervical hTERC genes by adopting FISH technique.

Raman and fluorescence characteristics of resonant inelastic X-ray scattering from doped superconducting cuprates

Measurements of spin excitations are essential for an understanding of spin-mediated pairing for superconductivity; and resonant inelastic X-ray scattering (RIXS) provides a considerable opportunity to probe high-energy spin excitations. However, whether RIXS correctly measures the collective spin excitations of doped superconducting cuprates remains under debate. Here we demonstrate distinct Raman- and fluorescence-like RIXS excitations of Bi_1.5Pb_0.6Sr_1.54CaCu₂O_8+δ. Combining photon-energy and momentum dependent RIXS measurements with theoretical calculations using exact diagonalization provides conclusive evidence that the Raman-like RIXS excitations correspond to collective spin excitations, which are magnons in the undoped Mott insulators and evolve into paramagnons in doped superconducting compounds. In contrast, the fluorescence-like shifts are due primarily to the continuum of particle-hole excitations in the charge channel. Our results show that under the proper experimental conditions RIXS indeed can be used to probe paramagnons in doped high-T_c cuprate superconductors.

The clinicopathological significance of NAB2-STAT6 gene fusions in 52 cases of intrathoracic solitary fibrous tumors

NAB2-STAT6 gene fusion drives STAT6 nuclear expression and is the pathognomonic hallmark of solitary fibrous tumors (SFTs). However, no study has systematically analyzed the clinicopathological features, STAT6 immunoexpression status, or the fusion variants of NAB2-STAT6 in intrathoracic SFTs. Fifty-two intrathoracic SFTs were retrieved to appraise histopathology, assess STAT6 immunoexpression, and determine NAB2-STAT6 fusion variants by RT-PCR. Location-relevant histologic mimics served as controls. Thirty-one pleura-based, 12 mediastinal/pericardial, and nine intrapulmonary lesions were histologically categorized into eight malignant, eight atypical, and 36 conventional or cellular SFTs, including two fat-forming and two giant cell angiofibroma-like SFTs. STAT6 distinctively decorated the tumoral nuclei in 51 (98%) SFTs. However, no nuclear staining was observed in the histological mimics. NAB2-STAT6 fusion was detected in 34 SFTs. Twenty-nine (85.3%) exhibited the major NAB2ex4-STAT6ex2/3 variant and 5 (14.7%) the minor NAB2ex6-STAT6ex16/17. NAB2ex4-STAT6ex2 was significantly associated with older age (P = 0.01) and pleuropulmonary tumors (P = 0.025). After a median follow-up of 33.9 (range, 0.3-174.6) months, adverse outcomes occurred in one atypical and five malignant SFTs, including two local relapses, one intrapulmonary metastasis, and three extrathoracic metastases. Inferior disease-free survival was univariately associated with atypical/malignant histology (P = 0.001) and a mitosis >4/10 HPFs (P = 0.0012) but was unrelated to fusion variants. In conclusion, the majority of intrathoracic SFTs exhibited STAT6 nuclear staining, and NAB2ex4-STAT6ex2/3 was the predominant fusion type. However, clinical aggressiveness is associated with atypical/malignant histology primarily contributed by increased mitosis but was unrelated to the NAB2-STAT6 fusion variants.

Pre-operative serum albumin level substantially predicts post-operative morbidity and mortality among patients with colorectal cancer who undergo elective colectomy

The quantitative relationship between serum albumin level and surgical outcomes has not been clearly established. This study included 3732 patients with colon cancer who underwent a potentially curative colectomy. Post-operative mortality and morbidity were analysed according to the patients' demographic data, pre-operative comorbidities, and tumour-related factors. Age, asthma, renal impairment, and albumin level were significantly associated with post-operative morbidity and mortality in the multivariate analyses. Logistic regression analysis revealed linear relationships of post-operative morbidity and mortality with albumin level. The morbidity and mortality rates decreased by 7.3% and 15.6%, respectively, for each 0.1 g/dL increase in albumin level. This finding remained significant in the hypoalbuminaemia subgroup but not in the normoalbuminaemia subgroup. That is, the morbidity and mortality rates significantly decreased by 8.7% and 17.7%, respectively (both P < 0.001), in the former group and decreased by 2.7% (P = 0.112) and 11.6% (P = 0.092), respectively, in the latter group. This study demonstrated that serum albumin level linearly predicted the post-operative morbidity and mortality among the colorectal cancer patients. Pre-operative serum albumin level may therefore be used as a continuous rather than a categorical marker of disease severity, especially among patients with hypoalbuminaemia.

Brain Natriuretic Peptide Stimulates Lipid Metabolism through Its Receptor NPR1 and the Glycerolipid Metabolism Pathway in Chicken Adipocytes

Brain natriuretic peptide (BNP) is related to lipid metabolism in mammals, but its effect and the molecular mechanisms underlying it in chickens are incompletely understood. We found that the level of natriuretic peptide precursor B (NPPB, which encodes BNP) mRNA expression in high-abdominal-fat chicken groups was significantly higher than that of low-abdominal-fat groups. Partial correlations indicated that changes in the weight of abdominal fat were positively correlated with NPPB mRNA expression level. In vitro, compared with the control group, preadipocytes with NPPB interference showed reduced levels of proliferation, differentiation, and glycerin in media. Treatments of cells with BNP led to enhanced proliferation and differentiation of cells and glycerin concentration, and mRNA expression of its receptor natriuretic peptide receptor 1 (NPR1) was upregulated significantly. In cells exposed to BNP, 482 differentially expressed genes were identified compared with controls without BNP. Four genes known to be related to lipid metabolism (diacylglycerol kinase; lipase, endothelial; 1-acylglycerol-3-phosphate O-acyltransferase 1; and 1-acylglycerol-3-phosphate O-acyltransferase 2) were enriched in the glycerolipid metabolism pathway and expressed differentially. In conclusion, BNP stimulates the proliferation, differentiation, and lipolysis of preadipocytes through upregulation of the levels of expression of its receptor NPR1 and key genes enriched in the glycerolipid metabolic pathway.

Risk factors associated with aortic remodeling in patients with Stanford type B aortic dissection after thoracic endovascular aortic repair

To determine the risk factors associated with adverse aortic remodeling after thoracic endovascular aortic repair (TEVAR) in patients with Stanford type B aortic dissection, we performed a retrospective analysis of 54 patients between January 2009 and June 2012 at the First Affiliated Hospital of Soochow University. All patients underwent TEVAR of the descending thoracic aorta. Multiple-logistic regression analyses were performed to identify risk factors associated with aortic remodeling. True-lumen and false-lumen volumes were increased (P < 0.001) and decreased (P < 0.001) after surgery, respectively. Therefore, the remodeling index increased after surgery (1.04 ± 0.6 to 2.06 ± 1.12, P < 0.001). Remodeling index and true-lumen volume were higher in the favorable aortic remodeling group compared to the adverse aortic remodeling group (P < 0.001), while the false-lumen volume was lower in the favorable aortic remodeling group (P < 0.001). Multivariate analyses revealed a branch originating from the false lumen (OR = 39.9, P < 0.01) and multiple tears (OR = 27.4, P < 0.01) to be independent risk factors for adverse aortic remodeling. Therefore, a branch originating from the false lumen and multiple tears were determined to be independent risk factors for adverse aortic remodeling after TEVAR in patients with Stanford type B aortic dissection.

NAB2-STAT6 fusion types account for clinicopathological variations in solitary fibrous tumors

Solitary fibrous tumor (SFT) is characterized by the inv12(q13q13)-derived NAB2-STAT6 fusion, which exhibits variable breakpoints and drives STAT6 nuclear expression. The implications of NAB2-STAT6 fusion variants in pathological features and clinical behavior remain to be characterized in a large cohort of SFTs. We investigated the clinicopathological correlates of this genetic hallmark and analyzed STAT6 immunoexpression in 28 intrathoracic, 37 extrathoracic, and 23 meningeal SFTs. These 88 tumors were designated as histologically nonmalignant in 75 cases and malignant in 13, including 1 dedifferentiated SFT. Eighty cases had formalin-fixed and/or fresh samples to extract assessable RNAs for RT-PCR assay, which revealed NAB2-STAT6 fusion variants comprising 12 types of junction breakpoints in 73 fusion-positive cases, with 65 (89%) falling into 3 major types. The predominant NAB2ex4-STAT6ex2 (n=33) showed constant breakpoints at the ends of involved exons, whereas the NAB2ex6-STAT6ex16 (n=16) and NAB2ex6-STAT6ex17 (n=16) might exhibit variable breakpoints and incorporate NAB2 or STAT6 intronic sequence. Including 73 fusion-positive and 7 CD34-negative SFTs, STAT6 distinctively labeled 87 (99%) SFTs in nuclei, exhibited diffuse reactivity in 73, but did not decorate 98 mimics tested. In seven fusion-negative cases, 6 were STAT6-positive, suggesting rare fusion variants not covered by RT-PCR assay. Regardless of histological subtypes, intrathoracic SFTs affected older patients (P=0.035) and tended to be larger in size (P=0.073). Compared with other variants, NAB2ex4-STAT6ex2/4 fusions were significantly predominant in the SFTs characterised by intrathoracic location (P<0.001), older age (P=0.005), decreased mitoses (P=0.0028), and multifocal or diffuse STAT6 staining (P=0.013), but not found to correlate with disease-free survival. Conclusively, STAT6 nuclear expression was distinctive in the vast majority of SFTs, including all fusion-positive tumors, and exploitable as a robust diagnostics of CD34-negative cases. Despite the associations of NAB2-STAT6 fusion variants with several clincopathological factors, their prognostic relevance should be further validated in large-scale prospective studies of SFTs.

Downregulated MTAP expression in myxofibrosarcoma: A characterization of inactivating mechanisms, tumor suppressive function, and therapeutic relevance

Myxofibrosarcomas are genetically complex and involve recurrently deleted chromosome 9p, for which we characterized the pathogenically relevant target(s) using genomic profiling. In 12 of the 15 samples, we detected complete or partial losses of 9p. The only aggressiveness-associated, differentially lost region was 9p21.3, spanning the potential inactivated methylthioadenosine phosphorylase (MTAP) that exhibited homozygous (4/15) or hemizygous (3/15) deletions. In independent samples, MTAP gene status was assessed using quantitative- and methylation-specific PCR assays, and immunoexpression was evaluated. We applied MTAP reexpression or knockdown to elucidate the functional roles of MTAP and the therapeutic potential of L-alanosine in MTAP-preserved and MTAP-deficient myxofibrosarcoma cell lines and xenografts. MTAP protein deficiency (37%) was associated with MTAP gene inactivation (P < 0.001) by homozygous deletion or promoter methylation, and independently portended unfavorable metastasis-free survival (P = 0.0318) and disease-specific survival (P = 0.014). Among the MTAP-deficient cases, the homozygous deletion of MTAP predicted adverse outcome. In MTAP-deficient cells, MTAP reexpression inhibited cell migration and invasion, proliferation, and anchorage-independent colony formation and downregulated cyclin D1. This approach also attenuated the tube-forming abilities of human umbilical venous endothelial cells, attributable to the transcriptional repression of MMP-9, and abrogated the susceptibility to L-alanosine. The inhibiting effects of MTAP expression on tumor growth, angiogenesis, and the induction of apoptosis by L-alanosine were validated using MTAP-reexpressing xenografts and reverted using RNA interference in MTAP-preserved cells. In conclusion, homozygous deletion primarily accounts for the adverse prognostic impact of MTAP deficiency and confers the biological aggressiveness and susceptibility to L-alanosine in myxofibrosarcomas.

Cytopathologic features of epithelioid inflammatory myofibroblastic sarcoma with correlation of histopathology, immunohistochemistry, and molecular cytogenetic analysis

BACKGROUND

Epithelioid inflammatory myofibroblastic sarcoma (E-IMS) is a recently established rare variant of inflammatory myofibroblastic tumor. It is characterized by a distinctive constellation of clinical, pathological, and molecular features, including a nearly exclusive intraabdominal location, strong male predilection, aggressive clinical course, predominance of epithelioid tumor cells, and Ran-binding protein 2 (RANBP2)-anaplastic lymphoma kinase (ALK) fusion in the majority of cases. To the authors' knowledge, the cytologic features of E-IMS have not been described to date.

METHODS

Cases of E-IMS that had corresponding cytology were searched. Six cytology samples (1 fine-needle aspiration sample, 2 imprint samples, and 3 effusion fluids) containing tumor cells were identified in 5 patients with E-IMS.

RESULTS

The cytomorphology included large monotonous epithelioid cells arranged in loose aggregates or singly, with admixed myxoid stroma, and an inflammatory background rich in neutrophils. The tumor cells had a large, round, eccentric nucleus with vesicular chromatin, prominent nucleoli, and moderate amounts of pale cytoplasm. Delicate thin-walled branching vessels traversing tumor aggregates was a prominent feature in a fine-needle aspiration sample. Immunohistochemically, ALK was positive in all 5 tumors, with a nuclear membranous staining pattern noted in 3 cases and a cytoplasmic pattern observed in the other 2 cases. ALK rearrangement was confirmed in all 5 tumors by molecular genetic studies.

CONCLUSIONS

The cytologic features of E-IMS recapitulate its histologic characteristics. E-IMS merits inclusion in the differential diagnosis of any intraabdominal, large epithelioid cell neoplasm. Confirmation of ALK rearrangement is advisable because patients may benefit from targeted therapies.

The rectenna design on contact lens for wireless powering of the active intraocular pressure monitoring system

This paper proposed a wireless power harvesting system with micro-electro-mechanical-systems (MEMS) fabrication for noninvasive intraocular pressure (IOP) measurement on soft contact lens substructure. The power harvesting IC consists of a loop antenna, an impedance matching network and a rectifier. The proposed IC has been designed and fabricated by CMOS 0.18 um process that operates at the ISM band of 5.8 GHz. The antenna and the power harvesting IC would be bonded together by using flip chip bonding technologies without extra wire interference. The circuit utilized an impedance transformation circuit to boost the input RF signal that improves the circuit performance. The proposed design achieves an RF-to-DC conversion efficiency of 35% at 5.8 GHz.

Polymorphism identification in BMP15 and GDF9 genes and their association with egg production in chickens

1. Mutations in growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are significantly associated with reproductive performance in mammals and the objective of the present study was to identify polymorphic sites and elucidate the association between genotypes in BMP15 and GDF9 and egg production. 2. Polymorphisms in BMP15 exon1 and GDF9 exon2 were detected by DNA sequencing and PCR-RFLP. Three SNPs were detected in each of BMP15 (A111G, C231T and C34T) and GDF9 (G593A, T824C and C896T). C34T leads to the substitution of Leu by Phe, which was predicted to affect protein function. 3. Results of the association analysis indicated that C34T had an effect on total egg production at 300 d of age (EN) and age at first laying (AFE). G593A affected EN and both C231T and C896T influenced AFE. The TGC1TGC1 diplotype in BMP15 had the highest EN. 4. In conclusion, EN may be significantly improved by marker-assisted selection of the BMP15 genotypes in maternal lines of Shaobo hens.

Myoepithelial carcinoma of the stomach: A diagnostic pitfall

Myoepithelioma/myoepithelial carcinomas are not commonly found in soft tissues and are especially rare at visceral sites. This report describes a case of a rare low-grade myoepithelial carcinoma of the stomach. A 61-year-old female patient presented with postprandial abdominal discomfort. Endoscopy revealed a 1.1 cm submucosal lesion. Local excision was performed after malignancy was confirmed by biopsy. The resection margin is free of tumor and she received no adjuvant therapy. The tumor was characterized by multinodular growth with biphasic epithelioid and spindle components. Infiltrative margin and nuclear pleomorphism are seen. Tumor cells were positive for both epithelial and myoepithelial markers. Evidence of epithelial differentiation was confirmed by electron microscopy. No EWSR1 rearrangement was detected. The final diagnosis was low-grade myoepithelial gastric carcinoma. The patient is currently well, and no evidence of recurrence or metastasis was found after ten-month of follow-up. Myoepithelial carcinoma should be considered in the differential diagnosis of a biphasic gastric tumor.

Cutaneous syncytial myoepithelioma: A case report with emphasis on the differential diagnosis of problematic dermal tumors

Cutaneous myoepithelioma is a peculiar and recently recognized neoplasm exhibiting purely myoepithelial differentiation. These lesions affect different areas of the body, and are characterized by heterogenous morphological and immunophenotypical features. The majority of cutaneous myoepitheliomas behave in a benign fashion, however, the risk for local recurrence is higher with incomplete resection. A relatively newly described variant of myoepithelioma exhibits syncytial cytological features. The current study reports a case of cutaneous syncytial myoepithelioma presenting as a painless and papular skin lesion. The presence of the Ewing sarcoma RNA-binding protein 1 gene rearrangement in the present case supported the diagnosis of a myoepithelial tumor. The patient subsequently underwent local excision of the tumor and was followed up twice in the year after surgery. At the time of writing, the patient was alive and no recurrences had been identified. Furthermore, the current study discusses how this myoepithelial neoplasm may be distinguished from other problematic spindle or epithelioid cell tumors, particularly superficial dermal lesions.

Skp2-dependent ubiquitination and activation of LKB1 is essential for cancer cell survival under energy stress

LKB1 is activated by forming a heterotrimeric complex with STRAD and MO25. Recent studies suggest that LKB1 has pro-oncogenic functions, besides acting as a tumor suppressor. How the LKB1 activity is maintained and how LKB1 regulates cancer development are largely unclear. Here we show that K63-linked LKB1 polyubiquitination by Skp2-SCF ubiquitin ligase is critical for LKB1 activation by maintaining LKB1-STRAD-MO25 complex integrity. We further demonstrate that oncogenic Ras acts upstream of Skp2 to promote LKB1 polyubiquitination by activating Skp2-SCF ubiquitin ligase. Moreover, Skp2-mediated LKB1 polyubiquitination is required for energy-stress-induced cell survival. We also detected overexpression of Skp2 and LKB1 in late-stage hepatocellular carcinoma (HCC), and their overexpression predicts poor survival outcomes. Finally, we show that Skp2-mediated LKB1 polyubiquitination is important for HCC tumor growth in vivo. Our study provides new insights into the upstream regulation of LKB1 activation and suggests a potential target, the Ras/Skp2/LKB1 axis, for cancer therapy.

AMACR amplification in myxofibrosarcomas: a mechanism of overexpression that promotes cell proliferation with therapeutic relevance

PURPOSE

Myxofibrosarcomas frequently display arm-level gains on 5p. We characterized the pathogenetic and therapeutic relevance of the α-methylacyl coenzyme A racemase (AMACR) at 5p13.3.

EXPERIMENTAL DESIGN

AMACR mRNA expression in myxofibrosarcomas was analyzed using the public transcriptome and laser-microdissected sarcoma cells. We performed florescence in situ hybridization (FISH) and immunohistochemistry in independent samples for clinical correlates. In AMACR-overexpressing myxofibrosarcoma cells and xenografts, we elucidated the biologic function of AMACR using RNA interference and explored the therapeutic effect and mechanism of an AMACR inhibitor, ebselen oxide.

RESULTS

AMACR protein overexpression and gene amplification were significantly associated with each other (P < 0.001), with higher tumor grades (both P ≤ 0.002), and univariately with worse metastasis-free survival (MFS; both P < 0.0001) and disease-specific survival (DSS; P = 0.0002 for overexpression; P = 0.0062 for amplification). AMACR protein overexpression also independently portended adverse outcome (DSS, P = 0.007; MFS, P = 0.001). However, 39% of AMACR-overexpression cases did not show gene amplification, implying alternative regulatory mechanisms. In myxofibrosarcoma cell lines, stable AMACR knockdown suppressed cell proliferation, anchorage-independent growth, and expression of cyclin D1 and cyclin T2. These growth-promoting attributes of AMACR were corroborated in the AMACR-silenced xenograft model and AMACR-underexpressed myxofibrosarcomas, showing decreased labeling for cyclin D1, cyclin T2, and Ki-67. Compared with fibroblasts, AMACR-expressing myxofibrosarcoma cells were more susceptible to ebselen oxide, which not only decreased viable cells, promoted proteasome-mediated degradation of AMACR protein, and induced cellular apoptosis in vitro, but also dose-dependently suppressed xenografted tumor growth in vivo.

CONCLUSIONS

Overexpressed AMACR in myxofibrosarcomas can be amplification-driven, associated with tumor aggressiveness, and may be relevant as a druggable target.

Impact of late toxicities on quality of life for survivors of nasopharyngeal carcinoma

BACKGROUND

To investigate the impact of physician-assessed late toxicities on patient-reported quality of life (QoL) for nasopharyngeal carcinoma (NPC) patients with long-term survival.

METHODS

A cross-sectional survey of QoL and late toxicities was conducted in 242 NPC patients with disease-free survival of more than 5 years after treatment. The QoL was assessed by the European Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30). Late toxicities including neuropathy, hearing loss, dysphagia, xerostomia, and neck fibrosis were recorded based on the criteria of Common Terminology Criteria for Adverse Events version 4.0 (CTCAE v.4.0). The general linear model multiple analysis of variance (GLM-MANOVA) was performed to predict factors associated with the QoL.

RESULTS

In the multifactor model of GLM-MANOVA, of the five late toxicities of CTCAE scales, neuropathy, hearing loss, and xerostomia were observed to be significantly associated with the overall outcome of the fifteen QLQ-C30 scales. A statistically significant trend (p <0.05) was observed, indicating that NPC survivors with more severe neuropathy, hearing loss or xerostomia had a worse outcome on global QoL, all five functional scales, and a variety of symptomatic scales.

CONCLUSIONS

To improve QoL outcome for NPC survivors, the development of a modern radiotherapeutic technique should not only focus on reduction of the dose to the salivary glands, but also on anatomical structures that are involved in neuropathy and hearing loss.

Phosphorylated p70S6K expression is an independent prognosticator for patients with esophageal squamous cell carcinoma

BACKGROUND

Although marked improvements have been made in surgical technique and chemoradiotherapy, the prognosis for patients with esophageal squamous cell carcinoma (ESCC) is still unsatisfactory. The mammalian target of rapamycin (mTOR) and its downstream signaling, p70 ribosomal S6 protein kinase (p70S6K) and eukaryotic translation initiation factor 4E (eIF4E)-binding protein 1 (4E-BP1), seem to play central roles in the regulation of cancer cell proliferation and survival. The significance of mTOR and its downstream targets, p70S6K and 4E-BP1, on the prognosis of ESCC remains uncertain, but this pathway is of particular concern because effective inhibitors are already available.

METHODS

Immunohistochemistry performed to evaluate the expression of phosphorylated mTOR (p-mTOR), phosphorylated p70S6K (p-p70S6K), phosphorylated 4E-binding protein 1 (p-4E-BP1), and Ki-67 using 105 surgically resected ESCC correlated with treatment outcome. The effect of the mTOR signaling pathway inhibitor everolimus on ESCC cell lines were investigated in vitro by the 3-(4.5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and in vivo by a nude mouse xenograft model.

RESULTS

Univariate analysis showed that p-mTOR overexpression (P = .022), p-p70S6K overexpression (P = .002), and Ki-67 labeling index >50% (P = .045) were associated with inferior overall survival (OS). In a multivariate comparison, p-p70S6K overexpression (P = .001; hazard ratio, 2.247) remained independently associated with worse OS. In cell lines and the xenograft model, everolimus significantly inhibited ESCC growth.

CONCLUSION

Overexpression of p-p70S6K is associated independently with a poor prognosis among patients with ESCC. The mTOR signaling pathway inhibitor everolimus can inhibit ESCC growth in vitro and in vivo. Our findings suggest that inhibition of mTOR signaling pathway may be a promising novel target for ESCC.