Prognostic and therapeutic relevance of cathepsin B in pediatric acute myeloid leukemia

AML, the second most common childhood leukemia is also one of the deadliest cancers. High mortality rate in AML is due to high incidence of relapse after complete remission with chemotherapy and inadequate prognostic assessment of patients. Moreover, there is dearth of therapeutic targets for treatment of this malignancy. Previous pilot study (n = 24) by our group revealed strong association between cathepsin B (CTSB) overexpression in peripheral blood mononuclear cells (PBMCs) and poor survival outcome in pediatric AML patients. To further explore the clinical utility and role of this protease in pediatric AML, we measured its enzymatic activity and mRNA expression in PBMCs as well as bone marrow mononuclear cells (BMMCs) of patients (n = 101) and PBMCs of healthy controls. Our results revealed elevated CTSB activity (P < 0.01) and overexpression of its mRNA (P < 0.01) in AML patients. Interestingly CTSB in BMMCs of patients emerged as an independent prognostic marker when compared with other known risk factors. Moreover, chemical inhibition of CTSB activity compromised survival, and induced apoptosis in an AML cell line THP-1. We further demonstrate the inhibition of CTSB activity by chemotherapeutic agent doxorubicin in these cells. Docking and simulation studies suggested the binding of doxorubicin to CTSB with higher affinity than its known specific inhibitor CA-074 Me, thereby indicating that cell death induced by this drug may at least partly be mediated by CTSB inhibition. CTSB, therefore, may serve as a prognostic marker and an attractive chemotherapeutic target in pediatric AML.

Expression and Clinical Implications of Cysteine Cathepsins in Gallbladder Carcinoma

Background: Gallbladder carcinoma (GBC) exhibits poor prognosis due to its detection at an advanced stage. Upregulation of lysosomal cysteine proteases cathepsin L (CTSL) and cathepsin B (CTSB) has been implicated in several tumorigenic processes. However, no such information in GBC was available. Therefore, the present study was planned to investigate the expression and clinical significance of these cathepsins in GBC.

Methods: Activities of CTSL and CTSB were assayed in the gallbladder (GB) tissues obtained from GBC patients (n = 43) and control subjects (n = 69). Protein and mRNA levels were quantified using immunohistochemistry and real-time PCR (qPCR), respectively. Finally, serum levels of CTSL and CTSB were estimated by ELISA. Receiver operating characteristic (ROC) curve analysis was used for the assessment of sensitivity, specificity, and diagnostic accuracy of these cysteine cathepsins in GBC. The association of combined CTSL and CTSB activity with overall survival was assessed using Kaplan Meier survival analysis.

Results: The expression and activity of both CTSL and CTSB were significantly increased (p < 0.050) in tumors of GBC patients as compared to controls. Enzymatic activity of CTSL+B and CTSB exhibited a strong positive association with tumor stage and lymph node involvement in GBC (p < 0.050). Interestingly, the elevated activity of combined CTSL+B was also associated with increased mortality in these patients. Furthermore, significantly enhanced levels of serum CTSL and CTSB were also observed in GBC (p < 0.050) as compared to controls. ROC analysis revealed high diagnostic significance of serum CTSB and CTSL for distinguishing GBC patients from controls with an area under the curve (AUC) of 82 and 77%, respectively.

Conclusion: This study, for the first time, demonstrates the clinical significance of CTSL and CTSB overexpression in GBC. Our findings may help improve the clinical management of this carcinoma.

PARP-1 inhibitor modulate β-catenin signaling to enhance cisplatin sensitivity in cancer cervix

Cisplatin is a keystone for treatment of both recurring and locally advanced cervical cancer. However toxic side effects and acquired resistance limits its efficacy. Enhanced DNA repair is one of the mechanisms through which cancer cells acquire cisplatin resistance. Inhibitors of PARP, which is a DNA damage repair enzyme, have been approved for use in BRCA mutated cancers like breast and ovary cancer. However little is known about the therapeutic efficacy of PARP inhibitors in cervical cancer, either as a single agent or in combination with cisplatin. We hypothesized that PARP-1 inhibition might improve the sensitivity of cervical cancer cells to cisplatin by diminishing DNA repair. To ascertain this, we determined effect of PARP-1 inhibition on cisplatin cytotoxicity in HeLa and SiHa cell lines. Combination of cisplatin with PJ34, a phenanthridinone-derived PARP-1 inhibitor, augmented cisplatin toxicity in vitro by decreasing cell proliferation, enhancing cell cycle block and cell death, and decreasing invasion and metastasis, when compared with either of the single agent alone. We further show that PARP-1 inhibition inhibited β-catenin signaling and its downstream components such as c-Myc, cyclin D1 and MMPs indicating a possible link between single strand base damage repair and WNT signaling. In conclusion, PARP-1 inhibition might augment cisplatin cytotoxicity in cervical cancer cells by modulating β-catenin signaling pathway. Combining PARP-1 inhibitors with cisplatin might be a promising approach to overcome cisplatin resistance and to achieve a better therapeutic effect.

Comparison of a grain-based diet supplemented with synthetic vitamin E versus a lucerne (alfalfa) hay-based diet fed to lambs in terms of carcass traits, muscle vitamin E, fatty acid content, lipid oxidation, and retail colour of meat

Dietary supplementation of vitamin E (VitE) in a synthetic or natural form was examined. Forty-eight lambs were assigned (n = 16) to either a grain-based diet at moderate (MOD, 42 mg∙kg^-1 VitE as all-rac α-tocopheryl acetate) or supranutritional (SUP, 285 mg∙kg^-1 of vitE) levels of synthetic VitE or a lucerne hay-based diet (LUC; 37 mg∙kg^-1 VitE) for 8 weeks. Meat from the LUC group had lower muscle n-6 and PUFA levels compared to meat from the MOD and SUP groups. Despite a similar VitE intake, muscle VitE was higher for LUC compared to MOD, while SUP lambs showed the highest VitE. Lipid oxidation did not differ between groups. For fresh meat, redness tended to be higher in LUC fed lambs than the other two groups, but brownness formation was only lower than the SUP group. For aged meat colour stability, redness tended to be higher in lambs fed SUP and LUC, whereas highest browning occurred in the MOD group.

Prognostic significance of plasma matrix metalloprotease-2 in pancreatic cancer patients

Background & objectives:

Pancreatic cancer has a propensity for wide stromal invasion. Matrix metalloprotease-2 (MMP-2) is a protease that degrades the peri-tumoural tissue and helps in tumour dissemination. Thus, this study was aimed to assess any association of plasma MMP-2 levels with clinicopathological parameters and survival of patients with pancreatic cancer.

Methods:

Plasma samples from 127 pancreatic cancer patients were analyzed for MMP-2 levels by ELISA. Survival and other clinicopathological parameters of patients were analyzed for any correlation with plasma MMP-2 levels.

Results:

The mean MMP-2 levels in pancreatic cancer patients were 560.3±222.0 ng/ml which were significantly elevated compared to chronic pancreatitis patients (P<0.001) and healthy individuals (P<0.05). The plasma levels of MMP-2 significantly correlated with tissue expression of this protease (P=0.004). However, MMP-2 levels did not exhibit any association either with clinicopathological parameters or with survival.

Interpretation & conclusions:

Elevated MMP-2 levels were observed in blood of pancreatic cancer patients which correlated with its tissue expression. However, these levels did not associate with survival or any clinicopathological parameters of patients. Further studies need to be done to confirm the prognostic/clinical significance of MMP-2 in cancer patients before and after surgery.

A glycoprotein from mammary gland secreted during involution promotes apoptosis: Structural and biological studies

Secretory signalling glycoprotein (SPX-40) from mammary gland is highly expressed during involution. This protein is involved in a programmed cell death during tissue remodelling which occurs at the end of lactation. SPX-40 was isolated and purified from buffalo (SPB-40) from the samples obtained during involution. One solution of SPB-40 was made by dissolving it in buffer containing 25 mM Tris-HCl and 50 mM NaCl at pH 8.0. Another solution was made by adding 25% ethanol to the above solution. The biological effects of SPB-40 dissolved in above two solutions were evaluated on MCF-7 breast cancer cell lines. Free SPB-40 indicated significant pro-apoptotic effects while ethanol exposed SPB-40 showed considerably reduced effects on the apoptosis. SPB-40 was crystallized in the native state. The crystals of SPB-40 were soaked in four separate solutions containing 25% acetone, 25% ethanol, 25% butanol and 25% MPD. Four separate data sets were collected and their structures were determined at high resolutions. In all the four structures, the molecules of acetone, ethanol, butanol and MPD respectively were observed in the hydrophobic binding pocket of SPB-40. As a result of which, the conformation of Trp78 was altered thus blocking the binding site in SPB-40 leading to the loss of activity.

Is VEGF under-expressed in Indian children with Perthes disease?

BACKGROUND

The role of vascular endothelial growth factor (VEGF) after ischaemic necrosis of the femoral head in Legg-Calve-Perthes disease (LCPD) has not been adequately studied in humans, especially in Indian population. Therefore, we aimed to evaluate the serum levels of VEGF-A in Indian children with various stages of LCPD and compare them with those of an age- and sex-matched control group of healthy children.

METHODS

In this case-control study, we enrolled 42 children (below 14 years age) suffering from LCPD and 21 age- and sex-matched healthy controls. Patients were classified radiographically according to Waldenstrom's classification. Serum VEGF-A was estimated by sandwich enzyme-linked immunosorbent assay technique. The serum values were compared between the patient group and the control group, as well as between the Waldenstrom subgroups. Results were expressed as means with ranges or median with interquartile range.

RESULTS

The mean age in the patient as well as the control group was 9 years (range 4-13 years). The median value (interquartile range) of serum VEGF-A was 162.5 pg/ml (673.75 pg/ml) in the patient group and 652 pg/ml (190.5 pg/ml) in the control group (p = 0.013). When compared between lower Waldenstrom stages (initial stage + stage of fragmentation) and higher Waldenstrom stages (re-ossification stage + stage of healing), the mean values of serum VEGF-A were 464.7 pg/ml (range 0-2211 pg/ml) and 301.1 pg/ml (range 0-1910 pg/ml), respectively (p = 0.305).

CONCLUSIONS

VEGF is under-expressed in Indian children suffering from LCPD. As VEGF acts as a key regulator of endochondral ossification, our finding may open new therapeutic approaches to the disease. Also, serum VEGF may act as a valuable marker for the follow-up of the disease. Our study also provides baseline data about serum VEGF-A levels in Indian cohort of LCPD patients. Future multi-centre studies are warranted with a larger sample size to fully appreciate the patho-physiological changes in VEGF occurring in LCPD.

p16INK4a overexpression as a predictor of survival in ocular surface squamous neoplasia

AIMS

To evaluate the expression and methylation status of the p16^INK4a gene in early and advanced American Joint Committee on Cancer (AJCC) stages of ocular surface squamous neoplasia (OSSN) and to correlate its association with clinicopathological features and survival.

METHODS

Sixty-four (35 early and 29 advanced AJCC stage) patients with OSSN formed part of this study and were followed up for 36-58 (mean 48±3.6) months. Immunohistochemical expression of the p16^INK4a protein and methylation status of the p16^INK4a gene were determined by methylation-specific PCR.

RESULTS

Overexpression of p16^INK4a was observed in 18/64 (28%) and hypermethylation in 35/64 (54.7%) OSSN cases. A gradual significant increase in the expression of p16^INK4a (0%-48%, P=0.03) and decrease in its methylation (75%-16%, P=0.001) was observed with disease progression from early to advanced tumour stage. Overexpression of p16^INK4a was significantly associated with palpebral location and diffuse growth pattern in both early and advanced T stage. Hypermethylation of p16^INK4a was significantly associated with history of longer sunlight exposure in both early and advanced T stage of OSSN cases. In advanced T stage, p16^INK4a overexpression was associated with reduced disease-free survival (P=0.02) and poor prognosis (HR, 0.2; P=0.03).

CONCLUSIONS

OSSN patients presenting at an advanced AJCC stage with p16^INK4a overexpression may require more aggressive treatment. Epigenetic inactivation of the p16^INK4a gene due to sunlight exposure could be responsible for pathogenesis of OSSN.

Prognostic significance of cathepsin L expression in pediatric acute myeloid leukemia

Overexpression of cathepsin L (CTSL), an endolysosomal cysteine protease, is associated with inferior survival of patients with various human malignancies. We evaluated the expression/activity of CTSL in peripheral blood mononuclear cells (PBMCs) and bone marrow mononuclear cells (BMMCs) of 103 pediatric acute myeloid leukemia (AML) patients to assess its prognostic significance in this malignancy. Thirty-five healthy siblings of patients served as controls. Our results revealed significantly higher CTSL activity (p < .0001), protein (p < .05), and mRNA levels (p < .01) in both PBMCs and BMMCs of patients as compared with controls. BMMCs displayed higher activity of CTSL than PBMCs (p < .01). A dramatic reduction in CTSL activity was recorded after chemotherapy in a significant proportion (74%) of patients (p < .0001). By multivariate analysis, CTSL in BMMCs emerged as a strong independent prognostic marker for overall survival (OS) (p = .004). Thus, our results suggest the potential utility of CTSL in predicting the outcome of pediatric AML.

Cathepsin L and B as Potential Markers for Liver Fibrosis: Insights From Patients and Experimental Models

OBJECTIVES

Cathepsin L (CTSL) and B (CTSB) have a crucial role in extracellular matrix (ECM) degradation and tissue remodeling, which is a prominent feature of fibrogenesis. The aim of this study was to determine the role and clinical significance of these cathepsins in liver fibrosis.

METHODS

Hepatic histological CTSL and CTSB expression were assessed in experimental models of liver fibrosis, patients with liver cirrhosis, chronic viral hepatitis, and controls by real-time PCR and immunohistochemistry. Plasma levels of CTSL and CTSB were analyzed in 51 liver cirrhosis patients (Child-Pugh stages A, B and C) and 15 controls.

RESULTS

Significantly enhanced CTSL mRNA (P=0.02) and protein (P=0.01) levels were observed in the liver of carbon tetrachloride-treated mice compared with controls. Similarly, hepatic CTSL and CTSB mRNA levels (P=0.02) were markedly increased in Abcb4-/- (ATP-binding cassette transporter knockout) mice compared with wild-type littermates. Elevated levels of CTSL and CTSB were also found in the liver (P=0.001) and plasma (P<0.0001) of patients with hepatic cirrhosis compared with healthy controls. Furthermore, CTSL and CTSB levels correlated well with the hepatic collagen (r=0.5, P=0.007; r=0.64, P=0.0001). CTSL and CTSB levels increased with the Child-Pugh stage of liver cirrhosis and correlated with total bilirubin content (r=0.4/0.2; P≤0.05). CTSL, CTSB, and their combination had a high diagnostic accuracy (area under the curve: 0.91, 0.89 and 0.96, respectively) for distinguishing patients from controls.

CONCLUSIONS

Our data demonstrate the overexpression of CTSL and CTSB in patients and experimental mouse models, suggesting their potential as diagnostic biomarkers for chronic liver diseases.

Human dipeptidyl peptidase III regulates G-protein coupled receptor-dependent Ca2+ concentration in human embryonic kidney 293T cells

The precise biological function of human dipeptidyl peptidase III (hDPP III) is poorly understood. Using luciferase reporter constructs responsive to change in Ca2+ and/or cAMP and Fura 2-AM fluorometric assay, we show a significant decrease in intracellular Ca2+ following hDPP III overexpression and angiotensin II stimulation in angiotensin II type 1 receptor (G-protein coupled receptor, GPCR) expressing HEK293T cells. Silencing the expression of hDPP III by siRNA reversed the effect of hDPP III overexpression with a concomitant increase in Ca2+. These results, for the first time, show involvement of hDPP III in GPCR dependent Ca2+ regulation in HEK293T cells.

Effects of a short-term supranutritional selenium supplementation on redox balance, physiology and insulin-related metabolism in heat-stressed pigs

Heat stress (HS) disrupts redox balance and insulin-related metabolism. Supplementation with supranutritional amounts of selenium (Se) may enhance glutathione peroxidase (GPX) activity and reduce oxidative stress, but may trigger insulin resistance. Therefore, the aim of this experiment was to investigate the effects of a short-term high Se supplementation on physiology, oxidative stress and insulin-related metabolism in heat-stressed pigs. Twenty-four gilts were fed either a control (0.20 ppm Se) or a high Se (1.0 ppm Se yeast, HiSe) diet for 2 weeks. Pigs were then housed in thermoneutral (20°C) or HS (35°C) conditions for 8 days. Blood samples were collected to study blood Se and oxidative stress markers. An oral glucose tolerance test (OGTT) was conducted on day 8 of thermal exposure. The HS conditions increased rectal temperature and respiration rate (both p < .001). The HiSe diet increased blood Se by 12% (p < .05) and ameliorated the increase in rectal temperature (p < .05). Heat stress increased oxidative stress as evidenced by a 48% increase in plasma advanced oxidized protein products (AOPPs; p < .05), which may be associated with the reductions in plasma biological antioxidant potential (BAP) and erythrocyte GPX activity (both p < .05). The HiSe diet did not alleviate the reduction in plasma BAP or increase in AOPPs observed during HS, although it tended to increase erythrocyte GPX activity by 13% (p = .068). Without affecting insulin, HS attenuated lipid mobilization, as evidenced by a lower fasting NEFA concentration (p < .05), which was not mitigated by the HiSe diet. The HiSe diet increased insulin AUC, suggesting it potentiated insulin resistance, although this only occurred under TN conditions (p = .066). In summary, HS induced oxidative stress and attenuated lipid mobilization in pigs. The short-term supranutritional Se supplementation alleviated hyperthermia, but did not protect against oxidative stress in heat-stressed pigs.

Effects of chromium supplementation on physiology, feed intake, and insulin related metabolism in growing pigs subjected to heat stress

Improving insulin sensitivity may reduce impacts of heat stress (HS) in pigs by facilitating heat dissipation. Chromium (Cr) has been reported to improve insulin sensitivity in pigs. Therefore, the aim of this experiment was to investigate whether Cr supplementation can mitigate HS in growing pigs. Thirty-six gilts were randomly assigned to 2 diets containing 0 (control) or 400 ppb Cr. After 14 d the supplemented pigs were allocated to either 8 d thermoneutral (20°C constant; TN) or cyclic HS (35°C, 0900 h to 1700 h) conditions and continued their respective diet (n = 9 per group). Growth performance was recorded during the 14-d supplementation period. The physiological responses to HS were monitored by measuring respiration rate, rectal temperature, blood gas chemistry, and feed intake during thermal exposure. Kinetics of plasma glucose, insulin and NEFA were studied by intravenous glucose tolerance test (IVGTT) on d 8 of thermal treatment. Results showed Cr alleviated the HS-increased rectal temperature (P < 0.05) and respiration rate (P < 0.01) at 1300 h and 1600 h during thermal exposure. However, Cr did not mitigate the reduction in average daily feed intake which was reduced by 35% during HS or the HS-induced respiratory alkalosis. Chromium tended to increase average daily gain (0.86 vs. 0.95 kg, P = 0.070) during the 14-d supplementation under TN conditions before thermal exposure, which might be associated with the potential of Cr in improving overall insulin sensitivity, as evidenced by a reduced insulin resistance index calculated by Homeostatic Model Assessment (HOMA-IR; 0.65 vs. 0.51, P = 0.013) and a tendency of reduced fasting plasma insulin concentration (1.97 vs. 1.67 μU/mL, P = 0.094). Heat stress decreased the acute insulin releasing rate (P = 0.012) and consequently slowed glucose clearance rate (P = 0.035) during IVGTT. Besides, HS enlarged the values of area under the curve of NEFA during IVGTT (P < 0.01), indicating a reduced lipid mobilization. In conclusion, HS reduced insulin response to IVGTT. Chromium supplementation exhibited a potential in improving insulin sensitivity and mitigating HS symptoms in growing pigs.

High dietary selenium and vitamin E supplementation ameliorates the impacts of heat load on oxidative status and acid-base balance in sheep

The objective of this study was to determine the efficacy of supranutritional dietary selenium and vitamin E (Vit E) to ameliorate the effect of heat stress (HS) on oxidative status and acid-base balance in sheep. Thirty-two Merino × Poll Dorset ewes were acclimated to indoor individual pen feeding of a pelleted control diet (0.24 g Se and 10 IU of Vit E/kg DM) for 1 wk. Sheep were then moved to metabolism cages in climatic chambers and randomly allocated to a 2 × 2 × 2 factorial design with the respective factors being dietary Se (0.24 and 1.20 mg/kg DM as Sel-Plex; Alltech, Australia), Vit E (10 and 100 IU/kg DM), and temperature for 2 wk. After 1 wk of acclimation in metabolic cages, 1 climatic chamber continued on thermoneutral (TN) conditions (18°C to 21°C and 40% to 50% relative humidity [RH]), and the other one was set to HS conditions (28°C to 40°C and 30% to 40% RH) for 1 wk. The sheep were then returned to individual pens and fed the control diet for 1 wk before being returned to the same diet as in the first period but a reversed thermal treatment for a further 2 wk. Physiological parameters were recorded 3 times daily, and blood samples were collected on d 1 and 7 of thermal treatment. Average respiration rate and rectal temperature of sheep were increased (P < 0.001) during HS; however, combined supranutritional supplementation of Se and Vit E reversed the effects of HS. Sheep given the high Se and high Vit E diet had a lower respiration rate (191 vs. 232 breaths/min; P = 0.012) and rectal temperature (40.33°C vs. 40.58°C; P = 0.039) under peak HS (1700 h) compared with those fed the low Se and low Vit E diet. Plasma reactive oxygen metabolites concentrations were reduced (P = 0.048) by 20%, whereas biological antioxidant potential was increased (P = 0.17) by 10% in sheep fed the high Se and high Vit E diet compared with those fed the low Se and low Vit E diet. Blood pH was elevated (P = 0.007) and bicarbonate was reduced (P = 0.049) under HS, and again, these effects were ameliorated by the high Se and high Vit E diet. Both white blood cell glutathione peroxidase gene expression and red blood cell lysate glutathione peroxidase activity were increased in sheep fed the high Se and high Vit E diet. These data suggest that supranutritional dietary Se or Vit E can reduce some of the negative effects of HS. However, the synergism between the 2 antioxidants improves their potential to ameliorate the impacts of HS in sheep.

Spontaneous Perforation of Stomach in a Neonate

Spontaneous gastric perforation is not a very common entity. If not suspected and managed in time, this is uniformly fatal. Although documented as early as in1825 exact pathology remains unclear even to date. A case of spontaneous rupture in a term neonate is being presented as a case report.J Nepal Paediatr Soc 2015;35(3):301-303. 

Dietary antioxidants at supranutritional doses modulate skeletal muscle heat shock protein and inflammatory gene expression in sheep exposed to heat stress

The objective of this study was to investigate the effects of chronic heat (thermal) stress and dietary antioxidant supplementation on the expression of heat shock proteins and inflammatory genes in the skeletal muscle of sheep. Twenty-four Merino × Poll Dorset crossbred ewes were allocated to either a control (10 IU vitamin E and 0.24 mg Se/kg DM) or high-antioxidant (VitE+Se; 100 IU vitamin E and 1.20 mg Se/kg DM) diet and were exposed to 2 thermal (temperature) treatments (thermoneutral [TN]: 18°C-21°C and 26%-30% relative humidity; heat stress [HS]: 28°C-40°C and 40%-50% relative humidity) for 1 wk. Physiological parameters were recorded daily, and muscle biopsies were conducted at the end of thermal treatments. Total RNA was extracted from muscle samples and reverse transcribed to cDNA for real-time PCR analysis. Respiration rates and rectal temperature were increased in response to HS (84.2 vs. 161 breaths per minute and 39.52°C vs. 40.06°C for TN and HS conditions, respectively; P < 0.001). There were interactions between dietary and thermal treatments, indicating that dietary antioxidant supplementation reduced respiration rate (P = 0.097) and rectal temperature (P = 0.086) of sheep during HS but not TN conditions. Skeletal muscle heat shock transcription factor 1 (HSF1) mRNA abundance was increased by HS (1.3-fold; P < 0.050) but was not changed (P = 0.77) by dietary antioxidant supplementation. The expression of skeletal muscle heat shock protein 70 (HSP70) mRNA was increased (P < 0.001) 3.5-fold by HS and tended (P = 0.08) to be increased by dietary antioxidant supplementation. Although there were no main effects of diet (P = 0.42) or HS (P = 0.47) on skeletal muscle HSP90 mRNA expression, there was an interaction (P = 0.040) such that HSP90 mRNA expression was increased (P = 0.010) in antioxidant-supplemented sheep under HS compared to TN conditions. Skeletal muscle nuclear factor kappa B (NF-κB) and tissue necrosis factor α (TNF-α) mRNA abundances were increased by exposure to heat (5.2-fold, P = 0.005 for NF-κB; 5.7-fold, P = 0.013 for TNF-α) ,but there was no main effect (P > 0.05) of dietary antioxidant supplementation. There was, however, an interaction between thermal and dietary treatments such that dietary antioxidant supplementation ameliorated the effect of HS on NF-κB and TNF-α mRNA expression. Taken together, these results indicate that high dietary antioxidants modulate skeletal muscle expression of heat shock proteins, proinflammatory cytokine, and NF-κB transcription, which may protect against HS in sheep.

High levels of cell-free circulating nucleic acids in pancreatic cancer are associated with vascular encasement, metastasis and poor survival

Pancreatic cancer is a highly aggressive disease with rapid invasion and early encasement of blood vessels. Hence, levels of circulating nucleic acids and tumor-associated mutations in them may have clinical importance. We analyzed the levels of circulating tumor DNA and oncogenic k-ras mutation in plasma of patients with pancreatic cancer and correlated their levels with survival and clinicopathological parameters. Higher levels of plasma DNA (>62 ng/mL) was found to associate significantly with lower overall survival time (p=.002), presence of vascular encasement (p=.030) and metastasis (p=.001). However, k-ras mutation status did not correlate with any of the clinicopathological parameters or survival. We conclude that circulating DNA in plasma can be an important predictor of prognosis in pancreatic cancer.

Plasma cathepsin L: A prognostic marker for pancreatic cancer

AIM: To assess the prognostic significance of cathepsin L, a cysteine protease that degrades the peri-tumoral tissue, in patients with pancreatic cancer.

METHODS: Plasma samples from 127 pancreatic cancer patients were analyzed for cathepsin L levels by ELISA. Out of these patients, 25 underwent surgery and their paraffin-embedded tissue was analyzed for cathepsin L expression by immunohistochemistry. Survival of patients and clinicopathological parameters was correlated with cathepsin L expression in plasma and tissue using appropriate statistical analysis.

RESULTS: The mean (± SD) cathepsin L in plasma samples of pancreatic cancer patients was 5.98 ± 2.5 ng/mL that was significantly higher compared to the levels in healthy controls (3.83 ± 0.45) or chronic pancreatitis patients (3.97 ± 1.06). Using ROC curve, a cut-off level of 5.0 ng/mL was decided for survival analysis. Elevated plasma levels of cathepsin L were found to be associated with poor prognosis (P = 0.01) in multivariate analysis. The plasma levels of the protease decreased after surgery. Though no significant correlation was seen between plasma and tissue expression of this protease, a trend did emerge that high cathepsin L expression in tissue correlated with its high levels in plasma.

CONCLUSION: Cathepsin L levels in plasma of pancreatic cancer patients may be used as a potential prognostic marker for the disease.

Abstract 1868: Clinical significance of cathepsin L and B expression in pediatric acute myeloid leukemia

Introduction: Cathepsin L and B are commonly expressed cysteine proteinases that play a major role in lysosomal bulk proteolysis, protein processing, matrix degradation, and tissue remodelling. In tumors there is deregulation of these proteases that interferes with these normal biological processes. In a pilot study done in our lab expression of cathepsin L and B were found to be significantly elevated in peripheral blood mononuclear cells (PBMCs) of pediatric AML patients. However the expression of these proteases in bone marrow aspirate, which represents almost true population of blasts, has never been studied before.

Methods: Enzymatic activities of cathepsin L and B were assayed in PBMCs and bone marrow mononuclear cells (BMMCs) of AML patients and healthy controls. Further expression of these proteases and its inhibitor were confirmed by western blotting and real time assay. Cell cycle analysis in PBMCs and BMMCs of these patients was performed by flow cytometry using propidium iodide.

Results: In the PBMCs of pediatric AML patients activity of cathepsin L and B was found to be significantly elevated as compared to healthy controls. Similarly, increased activity of cathepsin L and B was also observed in the BMMCs when compared with PBMCs of these patients. Furthermore, protein and mRNA expression also confirmed the increased level of these proteases in pediatric AML. The protein and mRNA expression of their endogenous inhibitor cystatin-C was found to be decreased in PBMCs and BMMCs of AML patients. Moreover, expression of these proteases correlated positively with the percentage of blasts and percentage of cells in S-phase.

Conclusion: This study for the first time demonstrates the increased expression of cathepsin L and B in the BMMCs and PBMCs of pediatric AML patients, along with a positive correlation with percentage of blasts, thereby suggesting a potential role of these proteases in the severity of this disease.

Citation Format: Garima Pandey, Sameer Bakhshi, Ratnakar Singh, Shyam S. Chauhan. Clinical significance of cathepsin L and B expression in pediatric acute myeloid leukemia. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1868. doi:10.1158/1538-7445.AM2014-1868

Dietary antioxidants at supranutritional doses improve oxidative status and reduce the negative effects of heat stress in sheep

The present study was undertaken to investigate the impact of heat (thermal) stress and dietary antioxidant supplementation on the oxidative and physiological status of sheep. Twenty-four Merino × Poll Dorset crossbred ewes were housed in 1 of 2 climatic chambers (thermoneutral or heat stress) and offered either a control (10 IU vitamin E/kg DM and 0.24 mg Se/kg DM) or high antioxidant (100 IU vitamin E/kg DM and 1.20 mg Se/kg DM) diet. The sheep were exposed to 2 thermal (temperature) treatments (thermoneutral [TN]: 18-21°C and 26-30% relative humidity; and heat stress [HS]: 28-40°C and 40-50% relative humidity) for 2 wk in a single reversal design. After 1 wk of dietary treatment, animals in 1 chamber were subjected to HS for 1 wk, with the temperature being increased to 40°C between 0900 and 1700 h and then maintained at 28°C overnight. Those sheep in the TN group were maintained at 18 to 21°C. Physiological parameters were recorded 4 times a day (0900, 1300, 1700, and 2100 h) and blood samples were collected on d 1 and 7 of heat treatment. Plasma samples and red blood cell lysates were assayed for oxidative stress biomarkers. The thermal treatments were then reversed and the above measures repeated. All measured physiological parameters were elevated (P < 0.001) by thermal treatment. Respiration rate was lower during HS in sheep supplemented with antioxidants as indicated by a diet × temperature × time interaction (P = 0.010). There was 13% decline (P = 0.014) in feed intake of the unsupplemented animals during HS whereas the same was maintained in sheep supplemented with high doses of antioxidants. Plasma reactive oxygen metabolites concentrations were reduced (114 vs. 85 units/dL; P < 0.005) while biological antioxidant potential tended to be increased (3,688 vs. 3,985 μmol/L; P = 0.070) in heat stressed sheep supplemented with antioxidants. The oxidative stress index was 30% lower (P < 0.001) in supplemented sheep (2.16 ± 0.06 arbitrary units) during HS than in unsupplemented sheep (3.12 ± 0.08 arbitrary units). Plasma advanced oxidation protein products tended (P = 0.070) to decrease in antioxidant supplemented heat stressed sheep as compared to their unsupplemented counterparts. It was concluded that heat stress negatively affects the oxidative status of sheep along with the physiological responses and some of these affects can be ameliorated through dietary antioxidants supplementation at supranutritional concentrations.

Transcription factor C/EBP-β mediates downregulation of dipeptidyl-peptidase III expression by interleukin-6 in human glioblastoma cells

Dipeptidyl-peptidase III (DPP III) is a cytosolic metallo-aminopeptidase implicated in various physiological and pathological processes. A previous study from our laboratory indicated an elevated expression of DPP III in glioblastoma (U87MG) cells. In the present study we investigated the role of interleukin-6 (IL-6), a pleiotropic cytokine produced by glial tumors, in the regulation of DPP III expression. Immunohistochemistry, western blotting and quantitative RT-PCR were used for quantitation of DPP III and IL-6 in human glioblastoma cells and tumors. Cell transfections and DPP III promoter reporter assays were performed to study the transcriptional regulation of DPP III by IL-6. Promoter deletion analysis, site directed mutagenesis, chromatin immunoprecipitation assays and small interfering RNA (siRNA) technology was employed to elucidate the molecular mechanism of IL-6 mediated regulation of DPP III expression in glioblastoma cells. Our results for the first time demonstrate a negative correlation (r = 0.632, P = 0.01) between DPP III and IL-6 in both human tumors and cultured glioblastoma cells. Treatment of U87MG cells with IL-6 significantly decreased DPP III expression with a concomitant increase in the levels of transcription factor CCAAT/enhancer binding protein beta (C/EBP-β). Deletion/mutagenesis of C/EBP-β binding motif of DPP III promoter significantly increased its activity and abolished its responsiveness to IL-6. This effect could also be mimicked by C/EBP-β siRNA. In conclusion our study for the first time demonstrates C/EBP-β mediated transcriptional downregulation of DPP III by IL-6. Our results demonstrating a negative correlation between IL-6 and DPP III taken together with the previously reported prognostic significance of this cytokine in glioblastoma suggests that DPP III may prove useful as a prognostic marker.

Slug is a predictor of poor prognosis in esophageal squamous cell carcinoma patients

Background

Slug, a regulator of epithelial mesenchymal transition, was identified to be differentially expressed in esophageal squamous cell carcinoma (ESCC) using cDNA microarrays by our laboratory. This study aimed to determine the clinical significance of Slug overexpression in ESCC and determine its correlation with clinicopathological parameters and disease prognosis for ESCC patients.

Methods

Immunohistochemical analysis of Slug expression was carried out in archived tissue sections from 91 ESCCs, 61 dysplastic and 47 histologically normal esophageal tissues. Slug immunopositivity in epithelial cells was correlated with clinicopathological parameters and disease prognosis over up to 7.5 years for ESCC patients.

Results

Increased expression of Slug was observed in esophageal dysplasia [cytoplasmic, 24/61 (39.3%) cases, p = 0.001, odd’s ratio (OR) = 4.7; nuclear, 11/61 (18%) cases, p < 0.001, OR = 1.36] in comparison with normal esophageal tissues. The Slug expression was further increased in ESCCs [cytoplasmic, 64/91 (70.3%) p < 0.001, OR = 10.0; nuclear, 27/91 (29.7%) p < 0.001, OR = 1.42]. Kaplan Meier survival analysis showed significant association of nuclear Slug accumulation with reduced disease free survival of ESCC patients (median disease free survival (DFS) = 6 months, as compared to those that did not show overexpression, DFS = 18 months; p = 0.006). In multivariate Cox regression analysis nuclear Slug expression [p= 0.005, Hazard’s ratio (HR) = 2.269, 95% CI = 1.289 - 3.996] emerged as the most significant independent predictor of poor prognosis for ESCC patients.

Conclusions

Alterations in Slug expression occur in early stages of development of ESCC and are sustained during disease progression. Slug may serve as a diagnostic biomarker and as a predictor of poor disease prognosis to identify ESCC patients that are likely to show recurrence of the disease.