Repurposing of ingenol mebutate for treating human colorectal cancer by targeting S100 calcium-binding protein A4 (S100A4).

Colorectal cancer (CRC) is the world's second most common cause of cancer-related death. Novel treatments are still urgently needed. S100 calcium-binding protein A4 (S100A4) was demonstrated to be an anticancer therapeutic target. Herein, we found that higher S100A4 expression was associated with a poorer prognosis in publicly available cohorts and a Taiwanese CRC patient cohort. To identify repurposed S100A4 inhibitors, we mined the Connectivity Map (CMap) database for clinical drugs mimicking the S100A4-knockdown gene signature. Ingenol mebutate, derived from the sap of the plant Euphorbia peplus, is approved as a topical treatment for actinic keratosis. The CMap analysis predicted ingenol mebutate as a potent S100A4 inhibitor. Indeed, both messenger RNA and protein levels of S100A4 were attenuated by ingenol mebutate in human CRC cells. In addition, CRC cells with higher S100A4 expressions and/or the wild-type p53 gene were more sensitive to ingenol mebutate, and their migration and invasion were inhibited by ingenol mebutate. Therefore, our results suggest the repurposing of ingenol mebutate for treating CRC by targeting S100A4.

Influence of RBC Indices on HbA1c Measurement by Capillary Electrophoresis and HPLC Methods.

BACKGROUND: HbA1c is the gold standard of diabetic surveys to monitor the long-term glycemic control. Anemia is cited as a major confounder to HbA1c analysis; however, the effect of RBC indices influences on HbA1c analysis is not known. The aim of this study is to compare ion-exchange high-performance liquid chromatography, and capillary electrophoresis to evaluate the influence of RBC parameters on HbA1c values in anemia patients. METHODS: Erythrocyte parameters were collected from the 307 randomly selected specimens from the Hematology division. HbA1c was measured on the same specimen using Tosoh G8 and Capillarys 2 Flex Piercing on the same day. RESULTS: There is acceptable concordance between the results of capillary electrophoresis and HPLC methods (R2 = 0.953, p < 0.001). However, significant differences in HbA1c value between the two assay methods were obtained in the patients with abnormal RBC indices (p < 0.001). CONCLUSIONS: Our results demonstrated HbA1c differences were significantly different in the patients with low Hb (≤ 8 g/dL) and high RDW-CV (≥ 13.7%). It is suggested that in the analysis of HbA1c level in anemia patients, simultaneous testing for hemoglobin level is needed. In addition, development of a new reference value of HBA1c for patients with severe anemia should be considered.

Specific diacylglycerols generated by hepatic lipogenesis stimulate the oncogenic androgen receptor activity in male hepatocytes.

BACKGROUND: Obesity-induced hepatocellular carcinoma (HCC) is more prevalent in males than in females, but the underlying mechanism remains unclear. The influence of hepatic androgen receptor (AR) pathway on the gender difference of HCC has been well documented. Here we investigated the role of hepatic lipogenesis, which is elevated in the livers of obese and nonalcoholic fatty liver disease (NAFLD) patients, in stimulating the AR pathway for the male preference of obesity induced HCC. METHODS: Male C57BL/6J mice were fed a fructose-rich high carbohydrate diet (HCD) to induce hepatic lipogenesis. The effect of hepatic lipogenesis on AR was examined by the expression of hydrodynamically injected AR reporter and the endogenous AR target gene; the mechanism was delineated in hepatoma cell lines and validated in male mice. RESULTS: The hepatic lipogenesis induced by a fructose-rich HCD enhanced the transcriptional activity of hepatic AR in male mice, which did not happen when fed a high fat diet. This AR activation was blocked by sh-RNAs or inhibitors targeting key enzymes in lipogenesis, either acetyl-CoA carboxylase subunit alpha (ACCα), or fatty acid synthase (FASN), in vivo and in vitro. Further mechanistic study identified that specific unsaturated fatty acid, the oleic acid (C18:1 n-9), incorporated DAGs produced by hepatic lipogenesis are the key molecules to enhance the AR activity, through activation of Akt kinase, and this novel mechanism is targeted by metformin. CONCLUSIONS: Our study elucidates a novel mechanism underlying the higher risk of HCC in obese/NAFLD males, through specific DAGs enriched by hepatic lipogenesis to increase the transcriptional activity of hepatic AR, a confirmed risk factor for male HCC.

Hypoxia-activated cytotoxic agent tirapazamine enhances hepatic artery ligation-induced killing of liver tumor in HBx transgenic mice.

Transarterial chemoembolization (TACE) is the main treatment for intermediate stage hepatocellular carcinoma (HCC) with Barcelona Clinic Liver Cancer classification because of its exclusive arterial blood supply. Although TACE achieves substantial necrosis of the tumor, complete tumor necrosis is uncommon, and the residual tumor generally rapidly recurs. We combined tirapazamine (TPZ), a hypoxia-activated cytotoxic agent, with hepatic artery ligation (HAL), which recapitulates transarterial embolization in mouse models, to enhance the efficacy of TACE. The effectiveness of this combination treatment was examined in HCC that spontaneously developed in hepatitis B virus X protein (HBx) transgenic mice. We proved that the tumor blood flow in this model was exclusively supplied by the hepatic artery, in contrast to conventional orthotopic HCC xenografts that receive both arterial and venous blood supplies. At levels below the threshold oxygen levels created by HAL, TPZ was activated and killed the hypoxic cells, but spared the normoxic cells. This combination treatment clearly limited the toxicity of TPZ to HCC, which caused the rapid and near-complete necrosis of HCC. In conclusion, the combination of TPZ and HAL showed a synergistic tumor killing activity that was specific for HCC in HBx transgenic mice. This preclinical study forms the basis for the ongoing clinical program for the TPZ-TACE regimen in HCC treatment.

The Expression Profile and Prognostic Significance of Metallothionein Genes in Colorectal Cancer.

Colorectal cancer (CRC) is a heterogeneous disease resulting from the combined influence of many genetic factors. This complexity has caused the molecular characterization of CRC to remain uncharacterized, with a lack of clear gene markers associated with CRC and the prognosis of this disease. Thus, highly sensitive tumor markers for the detection of CRC are the most essential determinants of survival. In this study, we examined the simultaneous downregulation of the mRNA levels of six metallothionein (MT) genes in CRC cell lines and public CRC datasets for the first time. In addition, we detected downregulation of these six MT mRNAs' levels in 30 pairs of tumor (T) and adjacent non-tumor (N) CRC specimens. In order to understand the potential prognostic relevance of these six MT genes and CRC, we presented a four-gene signature to evaluate the prognosis of CRC patients. Further discovery suggested that the four-gene signature (MT1F, MT1G, MT1L, and MT1X) predicted survival better than any combination of two-, three-, four-, five-, or six-gene models. In conclusion, this study is the first to report that simultaneous downregulation of six MT mRNAs' levels in CRC patients, and their aberrant expression together, accurately predicted CRC patients' outcomes.

Targeting of multiple oncogenic signaling pathways by Hsp90 inhibitor alone or in combination with berberine for treatment of colorectal cancer.

There is a wide range of drugs and combinations under investigation and/or approved over the last decade to treat colorectal cancer (CRC), but the 5-year survival rate remains poor at stages II-IV. Therefore, new, more-efficient drugs still need to be developed that will hopefully be included in first-line therapy or overcome resistance when it appears, as part of second- or third-line treatments in the near future. In this study, we revealed that heat shock protein 90 (Hsp90) inhibitors have high therapeutic potential in CRC according to combinative analysis of NCBI's Gene Expression Omnibus (GEO) repository and chemical genomic database of Connectivity Map (CMap). We found that second generation Hsp90 inhibitor, NVP-AUY922, significantly downregulated the activities of a broad spectrum of kinases involved in regulating cell growth arrest and death of NVP-AUY922-sensitive CRC cells. To overcome NVP-AUY922-induced upregulation of survivin expression which causes drug insensitivity, we found that combining berberine (BBR), a herbal medicine with potency in inhibiting survivin expression, with NVP-AUY922 resulted in synergistic antiproliferative effects for NVP-AUY922-sensitive and -insensitive CRC cells. Furthermore, we demonstrated that treatment of NVP-AUY922-insensitive CRC cells with the combination of NVP-AUY922 and BBR caused cell growth arrest through inhibiting CDK4 expression and induction of microRNA-296-5p (miR-296-5p)-mediated suppression of Pin1-ß-catenin-cyclin D1 signaling pathway. Finally, we found that the expression level of Hsp90 in tumor tissues of CRC was positively correlated with CDK4 and Pin1 expression levels. Taken together, these results indicate that combination of NVP-AUY922 and BBR therapy can inhibit multiple oncogenic signaling pathways of CRC.

Inactivation of p53 in pterygium influence miR-200a expression resulting in ZEB1/ZEB2 up-regulation and EMT processing.

Loss of p53 function has been linked to progression of pterygium. MiR-200a is known to be controlled by p53. Here, we hypothesize that expression of miR-200a and downstream ZEB1/ZEB2 genes are regulated epithelial-mesenchymal transition (EMT) involved in the pathogenesis and recurrence of pterygium. For this study, 120 primary pterygial samples were collected. Immunohistochemistry and real-time RT-PCR were performed to determine the expression of p53, p53 down-stream EMT associated protein and miR-200a. The molecular correlation of p53, miR-200a and downstream genes were confirmed using primary pterygium cells (PECs). Expression of miR-200a in pterygium tissues was significantly lower than in conjunctiva controls (p = 0.015). Up-regulated miR-200a levels were positively correlated with and p53 protein expression (p < 0.001). The miR-200a downstream ZEB1/ZEB1 protein expression were negative correlated with miR-200a expression. Cell model studies demonstrated that miR-200a controlled the EMT of PECs through up-regulated ZEB1, ZEB2 and Snail gene expression. Our study demonstrated that inactivation of p53 in pterygium may influence miR-200a, resulting in ZEB1/ZEB2 up-regulation and EMT processing of pterygium. Therefore, we suggest that expression of miR-200a play an important role in EMT processing and recurrence of pterygium.

MiR-92a Promotes Cell Metastasis of Colorectal Cancer Through PTEN-Mediated PI3K/AKT Pathway.

BACKGROUND: MicroRNAs regulate gene expression at the posttranscriptional level and play important roles in tumor development, progression, and metastasis. The aim of this study was to investigate the role of microRNA-92a (miR-92a) in metastasis of colorectal cancer (CRC). METHODS: One hundred fifty-eight CRC patients were enrolled. The expression of miR-92a, PTEN, and E-cadherin was analyzed by real-time PCR. Univariate (Kaplan-Meier) analysis was used to analyze primary outcomes included 5-year overall survival and tumor recurrence. CRC cell model studies were used to analyze the miR-92a-involved CRC metastasis. RESULTS: The expression of miR-92a in tumor tissues was significantly positively correlated with lymph node metastasis in CRC patients (p = 0.012). After adjusting for age, sex, and disease differentiation, this correlation remained significant (p = 0.01). In addition, there was a negative correlation between levels of miR-92a and the PTEN gene (p < 0.0001). No any association of miR-92a and E-cadherin was found (p = 0.128). Patients with high miR-92a/low PTEN had poorer overall survival and disease-free survival rates than those with high miR-92a/high PTEN, low miR-92a/high PTEN, and low miR-92a/low PTEN. The association of levels of miR-92a and PTEN with tumor cell migration in CRC was also confirmed in CRC cell models. CONCLUSIONS: We suggest that miR-92a is involved in lymph node metastasis of CRC patients through PTEN-regulated PI3K/AKT signaling pathway.

MicroRNA-184 Deregulated by the MicroRNA-21 Promotes Tumor Malignancy and Poor Outcomes in Non-small Cell Lung Cancer via Targeting CDC25A and c-Myc.

BACKGROUND: MicroRNA (miR)-184 has been reported to have a dual role in human cancers. However, the role of miR-184 in non-small cell lung cancer (NSCLC) remains unclear. METHODS: Wild-type or mutant CDC25A promoters were constructed by PCR and site-directed mutagenesis to verify whether miR-184 could inhibit CDC25A expression at post-transcription level. Boyden chamber assay was used to assess whether miR-184 could modulate cell invasiveness via targeting CDC25A and c-Myc. We utilized 124 tumors from NSCLC patients to determine miR-184, miR-21, PDCD4 mRNA, c-Myc mRNA, and CDC25A mRNA expression levels by means of real-time PCR analysis. The prognostic value of CDC25A, c-Myc, and miR-184 on overall survival (OS) and relapse-free survival (RFS) was evaluated by Kaplan-Meier and Cox regression analysis. RESULTS: MiR-184 suppressed CDC25A expression by enhancing the instability of its mRNA as a result of miR-184 binding to its coding region. An increase in CDC25A expression by means of a reduction in miR-184 promotes cell invasiveness. Moreover, a concomitant increase in CDC25A and c-Myc expression as a result of decreased miR-184 via the miR-21-mediated PDCD4 reduction is responsible for cell invasiveness. Among patients, miR-184 expression in lung tumors was found to correlate negatively with CDC25A mRNA, c-Myc mRNA, and miR-21 expression, but was positively related to PDCD4 mRNA expression. High-miR-184, High-CDC25A, or high-c-Myc mRNA tumors exhibited shorter OS and RFS periods than their counterparts. The worst OS and RFS were observed in low-miR-184/high-CDC25A/high-c-Myc tumors, followed by low-miR-184 /high-CDC25A, low-miR-184/high-c-Myc, high-c-Myc, and high-CDC25A tumors. CONCLUSIONS: MiR-184 as a tumor suppressor miR inhibits cell proliferation and invasion capability via targeting CDC25A and c-Myc. Low miR-184 level may predict worse prognosis in NSCLC patients.

Paxillin promotes tumor progression and predicts survival and relapse in oral cavity squamous cell carcinoma by microRNA-218 targeting.

High-risk human papillomavirus (HPV) 16-infected oral cavity squamous cell carcinoma (OCSCC) differs significantly from non-HPV-infected OCSCC. However, the molecular pathogenesis of HPV-infected OCSCC remains unclear. Paxillin (PXN) has been reported to promote lung tumor progression by miR-218 targeting. In addition, expression of miR-218 has been shown to be reduced by HPV16 E6 in cervical cancer. We thus asked whether PXN can promote tumor progression by E6-reduced miR-218 in OCSCC, especially in HPV-infected OCSCC. Mechanistic studies demonstrated that PXN expression increased markedly upon E6-mediated reductions in miR-218, resulting in increased colony formation and invasion capabilities in HPV-infected OCSCC cells. Among tumor specimens, HPV16/18 infection was negatively associated with miR-218 expression and positively associated with PXN expression. Kaplan-Meier and Cox regression models demonstrated that patients with low-miR-218 tumors or high-PXN tumors exhibited shorter overall survival (OS) and relapse-free survival (RFS) than those with high-miR-218 tumors or low-PXN tumors. Interestingly, HPV-infected patients with low-miR-218, high-PXN tumors and both combinations exhibited the worst OS and RFS compared with patients in their counterparts. These observations in patients were consistent with the findings from the cell model. Therefore, we suggest that PXN might be targeted to suppress tumor progression and consequently to improve outcomes in OCSCC, especially in HPV-infected OCSCC.

Epidemiology and molecular characterization of macrolide-resistant Streptococcus pyogenes in Taiwan.

Our multicenter nationwide surveillance data indicated that erythromycin (ERY) resistance among group A Streptococcus (GAS) isolates in Taiwan declined from 53.1% in 1998 and 2000 to 14.6% in 2002 and 2004 and 10.7% in 2006 to 2010 (P < 0.01). The present study aimed to assess the epidemiology of GAS in Taiwan and identify factors associated with ERY resistance. All 127 ERY-resistant (ERY(r)) isolates and 128 randomly selected ERY-susceptible (ERY(s)) isolates recovered from 1998 to 2010 were emm typed. ERY(r) isolates were also characterized by ERY resistance phenotype and mechanisms and pulsed-field gel electrophoresis (PFGE). Multilocus sequence typing was performed on selected ERY(r) isolates. The predominant emm types in ERY(r) isolates were emm22 (n = 33, 26.0%), emm12 (n = 24, 18.9%), emm4 (n = 21, 16.5%), and emm106 (n = 15, 11.8%). In ERY(s) isolates, emm12 (n = 27, 21.9%), emm1 (n = 18, 14.1%), emm106 (n = 16, 12.5%), and emm11 (n = 9, 7.1%) predominated. The most common ERY resistance phenotype was the M phenotype (resistant to macrolides) (70.9%), with all but one isolate carrying mef(A), followed by the constitutive macrolide-lincosamide-streptogramin B resistance (cMLSB) phenotype (26.8%), with isolates carrying erm(B) or erm(TR). ERY(r) isolates of the emm12-sequence type 36 (ST36) lineage with the cMLSB phenotype were mostly present before 2004, while those of the emm22-ST46 lineage with the M phenotype predominated in later years. Recovery from respiratory (throat swab) specimens was an independent factor associated with ERY resistance. emm1 and emm11 GAS isolates were significantly associated with ERY(s), while emm22 was detected only in ERY(r) GAS. In addition, emm106 isolates were prevalent among the abscess/pus isolates, whereas emm12 isolates were strongly associated with a respiratory (throat) origin. In addition to identifying factors associated with ERY resistance in GAS, our study provides helpful information on the changing GAS epidemiology in Taiwan.

MiRNA-221 negatively regulated downstream p27Kip1 gene expression involvement in pterygium pathogenesis.

PURPOSE: MiRNAs are small noncoding RNAs that have been implicated in tumor development. They regulate target gene expression either by mRNA degradation or by translation repression. Activation of ß-catenin has been linked to pterygium progression. Here, we hypothesize that ß-catenin-associated miRNA, miRNA-221, and downstream p27Kip1 gene expression are correlated with the pathogenesis of pterygium. METHODS: We collected 120 pterygial and 120 normal conjunctival samples for this study. Immunohistochemistry and real-time reverse transcription (RT)-PCR were performed to determine ß-catenin protein localization, miR-221, and p27Kip1 gene expression. Pterygium cell line (PECs) cell models were used to confirm the effect of ß-catenin, miR-221, and p27Kip1 gene in the proliferation of pterygium cells. RESULTS: Seventy-two (60.0%) pterygial specimens showed high miR-221 expression levels, which was significantly higher than the control groups (13 of 120, 10.8%, p<0.0001). MiR-221 expression was significantly higher in ß-catenin-nuclear/cytoplasmic-positive groups than in ß-catenin membrane-positive and negative groups (p=0.001). We also found that p27Kip1 gene expression in pterygium was negatively correlated with miR-221 expression (p=0.002). In the clinical association, miR-221 expression was significantly higher in the fleshy and intermediate groups than in the atrophic group (p=0.007). The association of miR-221, p27Kip1 and proliferation of pterygium were also confirmed in the PECs model. CONCLUSIONS: Our study demonstrated that activation of ß-catenin in pterygium may interact with miR-221, resulting in p27Kip1 gene downregulation that influences pterygium pathogenesis.

Increased levels of circulating advanced glycation end-products in menopausal women with osteoporosis.

BACKGROUND: Advanced glycation end-products (AGEs) can accumulate in organs and tissues during ageing and diabetes. Increased levels of AGEs are found in the bone tissue of patients with osteoporosis. The purpose of this study was to evaluate circulating AGEs in patients with osteoporosis. METHODS: We evaluated plasma AGEs, osteoporosis-related biomarkers, and bone mass in 82 menopausal women with osteoporosis or osteopenia, 16 young women with osteopenia, and 43 healthy women without osteoporosis or osteopenia. RESULTS: Higher levels of serum AGEs were found in the osteoporosis or osteopenia group compared to healthy women (P < 0.0001). A negative correlation was observed between serum AGEs and lumbar spine bone density (BMD of lumbar spine, r = -0.249, P = 0.028; T-score of lumbar spine, r = -0.261, P = 0.021). Women with a increased level of serum AGEs (> 8.12 U/mL) had a 5.34-fold risk of osteopenia regarding lumbar spine T-score and a 3.31-fold risk of osteopenia regarding the hip T-score. CONCLUSION: Serum AGEs could be used to monitor the severity and progression of osteoporosis. An increased serum level of AGEs was associated with impaired bone formation and was a risk factor for the development of osteoporosis. Targeting AGEs may represent a novel therapeutic approach for primary or secondary osteoporosis.

Circulating anti-cyclic citrullinated peptide antibody in patients with rheumatoid arthritis and chronic obstructive pulmonary disease.

Anti-cyclic citrullinated peptide (anti-CCP) antibody is highly specific for diagnosing rheumatoid arthritis (RA). Cigarette smoking is a lifestyle and environmental factor associated with anti-CCP production and is strongly associated with chronic obstructive pulmonary disease (COPD). This study assessed levels of anti-CCP antibodies and rheumatoid factor (RF) among patients with RA and COPD. The study sample comprised 63 patients with RA and 70 patients with COPD, all of whom underwent assessment of anti-CCP antibody and RF levels. Testing revealed that 54.2% of RA patients and 0% of COPD patients were positive for anti-CCP antibodies. Additionally, 82.5% of RA patients and 42% of COPD patients were positive for RF. Among RA patients, levels of anti-CCP antibodies were higher among smokers than among nonsmokers (242.7 ± 128.3 vs. 68.1 ± 112.1, P < 0.001). COPD patients had low titers of RF but were negative for anti-CCP antibodies. The presence of anti-CCP antibodies was a reliable serologic marker in RA diagnosis and was associated with cigarette smoking.

Shear Stress and Sub-Femtomolar Levels of Ligand Synergize to Activate ALK1 Signaling in Endothelial Cells.

Endothelial cells (ECs) respond to concurrent stimulation by biochemical factors and wall shear stress (SS) exerted by blood flow. Disruptions in flow-induced responses can result in remodeling issues and cardiovascular diseases, but the detailed mechanisms linking flow-mechanical cues and biochemical signaling remain unclear. Activin receptor-like kinase 1 (ALK1) integrates SS and ALK1-ligand cues in ECs; ALK1 mutations cause hereditary hemorrhagic telangiectasia (HHT), marked by arteriovenous malformation (AVM) development. However, the mechanistic underpinnings of ALK1 signaling modulation by fluid flow and the link to AVMs remain uncertain. We recorded EC responses under varying SS magnitudes and ALK1 ligand concentrations by assaying pSMAD1/5/9 nuclear localization using a custom multi-SS microfluidic device and a custom image analysis pipeline. We extended the previously reported synergy between SS and BMP9 to include BMP10 and BMP9/10. Moreover, we demonstrated that this synergy is effective even at extremely low SS magnitudes (0.4 dyn/cm2) and ALK1 ligand range (femtogram/mL). The synergistic response to ALK1 ligands and SS requires the kinase activity of ALK1. Moreover, ALK1's basal activity and response to minimal ligand levels depend on endocytosis, distinct from cell-cell junctions, cytoskeleton-mediated mechanosensing, or cholesterol-enriched microdomains. However, an in-depth analysis of ALK1 receptor trafficking's molecular mechanisms requires further investigation.

Microcirculatory Impairment and Cerebral Injury in Hydrocephalus and the Effects of Cerebrospinal Fluid Diversion.

BACKGROUND AND OBJECTIVES: Hydrocephalus is characterized by progressive enlargement of cerebral ventricles, resulting in impaired microvasculature and cerebral hypoperfusion. This study aimed to demonstrate the microvascular changes in hydrocephalic rats and the effects of cerebrospinal fluid (CSF) release on cerebral blood flow (CBF). METHODS: On postnatal day 21 (P21), male Wistar rats were intracisternally injected with either a kaolin suspension or saline. On P47, Evan's ratio (ER) was measured using MRI. On P49, the arteriolar diameter and vascular density of the pia were quantified using a capillary video microscope. The CBF was measured using laser Doppler flowmetry. The expressions of NeuN and glial fibrillary acidic protein determined by immunochemical staining were correlated with the ER. The CBF and rotarod test performance were recorded before and after CSF release. The expressions of 4-hydroxynonenal (4-HNE) and c-caspase-3 were studied on P56. RESULTS: Ventriculomegaly was induced to varying degrees, resulting in the stretching and abnormal narrowing of pial arterioles, which regressed with increasing ER. Quantitative analysis revealed significant decreases in the arteriolar diameter and vascular density in the hydrocephalic group compared with those in the control group. In addition, the CBF in the hydrocephalic group decreased to 30%-50% of that in the control group. In hydrocephalus, the neurons appear distorted, and the expression of 4-HNE and reactive astrogliosis increase in the cortex. After CSF was released, improvements in the CBF and rotarod test performance were inversely associated with the ER. In addition, the levels of 4-HNE and c-caspase-3 were further elevated. CONCLUSION: Rapid ventricular dilatation is associated with severe microvascular distortion, vascular regression, cortical hypoperfusion, and cellular changes that impair the recovery of CBF and motor function after CSF release. Moreover, CSF release may induce reperfusion injury. This pathophysiology should be taken into account when treating hydrocephalus.

Activation of NF-κB by SOD2 promotes the aggressiveness of lung adenocarcinoma by modulating NKX2-1-mediated IKKß expression.

Magnesium superoxide dismutase (SOD2) has been shown to cause dysfunction of p53 transcriptional activity, whereas, in turn, SOD2 expression is regulated by p53 to modulate lung tumorigenesis. In this study, we found that the level of SOD2 expression in a panel of lung cancer cells was negatively correlated with that of NK2 homeobox 1 (NKX2-1) but was not associated with p53 status. Mechanistic studies indicated that a decrease in NKX2-1 caused by SOD2-activated IKKß transcription was achieved by derepression of binding of Sp1 to the IKKß promoter. Immunoprecipitation, glutathione S-transferase pull-down experiments and electrophoretic mobility shift assays demonstrated a direct interaction between NKX2-1 and Sp1, blocking Sp1-mediated IKKß transcription. SOD2-mediated nuclear factor-kappaB activation, via elevation of IKKß transcription, promoted anchorage-independent soft-agar growth, invasion and xenograft tumor formation, because of development of the epithelial-to-mesenchymal transition. The expression level of NKX2-1 messenger RNA was negatively associated with the extent of SOD immunostaining and the IKKß messenger RNA expression level in lung tumors. The extent of SOD2 immunostaining and IKKß messenger RNA levels may independently predict overall survival and relapse-free survival in lung adenocarcinoma patients. In summary, we found that SOD2 activates nuclear factor-kappaB signaling by increasing IKKß transcription, which results in progression of lung adenocarcinoma and poorer patient outcomes. We suggest that IKKß may potentially be targeted to improve outcomes in patients with SOD2-positive tumors.

Association of epidermal growth factor receptor mutations with human papillomavirus 16/18 E6 oncoprotein expression in non-small cell lung cancer.

BACKGROUND: Lung cancers in women, in nonsmokers, and in patients with adenocarcinoma from Asia have more prevalent mutations in the epidermal growth factor receptor (EGFR) gene than their counterparts. However, the etiology of EGFR mutations in this population remains unclear. The authors hypothesized that the human papillomavirus (HPV) type 16/18 (HPV16/18) E6 oncoprotein may contribute to EGFR mutations in Taiwanese patients with lung cancer. METHODS: One hundred fifty-one tumors from patients with lung cancer were enrolled to determine HPV16/18 E6 and EGFR mutations using immunohistochemistry and direct sequencing, respectively. Levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) in lung tumors and cells were evaluated using immunohistochemistry and liquid chromatography-mass spectrometry/mass spectrometry. An supF mutagenesis assay was used to determine H2 O2 -induced mutation rates of lung cancer cells with or without E6 expression. RESULTS: Patients with E6-positive tumors had a greater frequency of EGFR mutations than those with E6-negative tumors (41% vs 20%; P = .006). Levels of 8-oxo-dG were correlated with EGFR mutations (36% vs 16%; P = .012). Two stable clones of E6-overexpressing H157 and CL-3 cells were established for the supF mutagenesis assay. The data indicated that the cells with high E6 overexpression had higher H2 O2 -induced SupF gene mutation rates compared with the cells that expressed lower levels of E6 and compared with vector control cells. CONCLUSIONS: HPV16/18 E6 may contribute in part to EGFR mutations in lung cancer, at least in the Taiwanese population.

Loss of TIMP-3 promotes tumor invasion via elevated IL-6 production and predicts poor survival and relapse in HPV-infected non-small cell lung cancer.

Human papillomavirus (HPV) 16/18 E6 oncoprotein is expressed in lung tumors and is associated with p53 inactivation. The tissue inhibitor of metalloproteinase 3 (TIMP-3) is essential for limiting inflammation; therefore, we expected that TIMP-3 loss might induce chronic inflammation, thereby promoting tumor malignancy as well as poor survival and relapse in patients with HPV-infected non-small cell lung cancer. In this study, the loss of TIMP-3 by loss of heterozygosity and/or promoter hypermethylation was more frequent in HPV16/18 E6-positive tumors than in E6-negative tumors. To explore the possible underlying mechanism, E6-negative TL4 and CL1-0 cells were transfected with an E6 cDNA plasmid. A marked decrease in TIMP-3 expression was caused by promoter hypermethylation via increased DNA (cytosine-5-)-methyltransferase 1 (DNMT1) expression. Mechanistic studies indicated that TIMP-3 loss promoted interleukin-6 (IL-6) production, which led to cell invasion and anchorage-independent growth on soft agar plates. Kaplan-Meier and Cox regression models showed that patients with low-TIMP-3/high-IL-6 tumors had shorter overall survival and relapse-free survival periods when compared with patients with high-TIMP-3/low-IL-6 tumors. In summary, loss of TIMP-3 may increase IL-6 production via the tumor necrosis factor α/nuclear factor κB axis, thereby promoting tumor malignancy and subsequent relapse and poor survival in patients with HPV-infected non-small cell lung cancer.

Cytoplasmic Ape1 expression elevated by p53 aberration may predict survival and relapse in resected non-small cell lung cancer.

BACKGROUND: Subcellular localization of apurinic/apyrimidinic endonuclease-1/redox factor-1 (Ape1) has been demonstrated to promote lung tumor malignancy via NF-κB activation. We hypothesized that increased cytoplasmic Ape1 expression might cause NF-κB activation by p53 aberration, and result in poor outcome in non-small cell lung cancer (NSCLC). METHODS: Herein, knockdown of E6 or p53 and overexpression of E6 were performed in various lung cancer cells to test whether cytoplasmic Ape1 expression could be elevated by p53 aberration. To examine whether cytoplasmic Ape1 could be associated with patients' outcome, 125 lung tumors from patients with NSCLC were collected to determine Ape1 protein and mRNA expression by immunohistochemistry and real-time RT-PCR. RESULTS: Our data showed that cytoplasmic Ape1 decreased in E6-knockdown TL-1 cells and increased in E6-overexpressed TL-4 and p53-knockdown H520 cells; and cell invasion capability was dependent on the presence of cytoplasmic Ape1. Increases in cytoplasmic Ape1 by p53 aberration may be through activation of Ape1 transcription and S-nitrosation of Ape1 protein. Kaplan-Meier and Cox models showed that patients with high cytoplasmic Ape1 had shorter cancer-specific survival (CSS) and relapse-free survival (RFS) periods than did those with low cytoplasmic Ape1. CONCLUSIONS: We suggest that cytoplasmic Ape1 expression elevated by p53 aberration may be used to predict poor survival and relapse in patients with NSCLC.