MicroRNA-21 knockdown disrupts glioma growth in vivo and displays synergistic cytotoxicity with neural precursor cell delivered S-TRAIL in human gliomas

Despite the development of new glioma therapies that allow for tumor-targeted in situ delivery of cytotoxic drugs, tumor resistance to apoptosis remains a key impediment to effective treatment. Mounting evidence indicates that microRNAs (miRNA) might play a fundamental role in tumorigenesis, controlling cell proliferation and apoptosis. In gliomas, microRNA-21 (miR-21) levels have been reported to be elevated and their knockdown is associated with increased apoptotic activity. We hypothesized that suppression of miR-21 might sensitize gliomas for cytotoxic tumor therapy. With the use of locked nucleic acid (LNA)-antimiR-21 oligonucleotides, bimodal imaging vectors, and neural precursor cells (NPC) expressing a secretable variant of the cytotoxic agent tumor necrosis factor-related apoptosis inducing ligand (S-TRAIL), we show that the combined suppression of miR-21 and NPC-S-TRAIL leads to a synergistic increase in caspase activity and significantly decreased cell viability in human glioma cells in vitro. This phenomenon persists in vivo, as we observed complete eradication of LNA-antimiR-21-treated gliomas subjected to the presence of NPC-S-TRAIL in the murine brain. Our results reveal the efficacy of miR-21 antagonism in murine glioma models and implicate miR-21 as a target for therapeutic intervention. Furthermore, our findings provide the basis for developing combination therapies using miRNA modulation and cytotoxic tumor therapies.     

Utility of a comprehensive immunohistochemical panel in the differential diagnosis of spindle cell lesions of the urinary bladder

Spindle cell lesions of the urinary bladder are uncommon, but when encountered in clinical practice, pose a difficult diagnostic challenge as the differential diagnostic considerations are vast. Pseudosarcomatous processes significantly overlap with malignant tumors (sarcomatoid urothelial carcinoma and leiomyosarcoma) in their morphology and published immunohistochemical profile [pancytokeratin pan (CK), smooth muscle actin (SMA), and desmin]. p63 has been studied rarely and CK 5/6 and CK 34betaE12 have not been analyzed in the bladder in this diagnostic context. In the current study, 45 typical examples of spindle cell lesions [10 pseudosarcomatous myofibroblastic proliferations (PMP), 22 sarcomatoid urothelial carcinomas, and 13 smooth muscle tumors] of the urinary bladder were immunostained with a panel containing broad spectrum anticytokeratin antibodies (OSCAR or AE1/AE3), as well as antibodies to CK 34betaE12, CK 5/6, p63, SMA, and anaplastic lymphoma kinase (ALK). The immunoreactivity was as follows: PMP-CK (OSCAR) 7/10 (70%), CK (AE1/AE3) 7/9 (78%), CK 34betaE12 0/10 (0%), CK 5/6 0/9 (0%), p63 0/9 (0%), SMA 10/10 (100%), ALK 2/10 (20%); sarcomatoid urothelial carcinoma-CK (OSCAR) 15/22 (68%), CK (AE1/AE3) 14/20 (70%), CK 34betaE12 5/20 (25%), CK5/6 6/22 (27%), p63 11/22 (50%), SMA 16/22 (73%), ALK 0/22 (0%); and smooth muscle tumors-CK (OSCAR) 7/13 (54%), CK (AE1/AE3) 7/12 (58%), CK 34betaE12 0/12 (0%), CK 5/6 0/12 (0%), p63 3/13 (23%), SMA 11/13 (85%), ALK 0/13 (0%). Positivity for keratin was typically focal to moderate in smooth muscle tumors and more commonly moderate to diffuse in sarcomatoid carcinomas and PMP. Our data indicate that there is significant immunohistochemical overlap between the different spindle cell lesions, each of which has unique clinicopathologic, prognostic, and therapeutic ramifications. Within the context of morphology, an immunohistochemical panel composed of broad-spectrum antibodies to cytokeratin as well as antibodies to SMA, ALK, p63, and CK 5/6 will be a useful diagnostic adjunct: a combination of pankeratin, SMA, and ALK positivity favors PMP; expression of several cytokeratin and especially CK 34betaE12 and CK 5/6 with p63 favors sarcomatoid carcinoma and SMA positivity with overall absence of other markers favors leiomyosarcoma.     

Epidemiology of mesothelioma in Egypt. A ten-year (1998-2007) multicentre study

Introduction

Mesothelioma is a cancer strongly linked to exposure to carcinogenic minerals, especially asbestos. The aim of the study was to detect the incidence of malignant pleural mesothelioma (MPM) in Egypt, to clarify the impact of occupational and environmental risk factors, and to characterise its demographic features.

Material and methods

They were 584 cases diagnosed as MPM detected in Cairo University Hospitals and National Cancer Institute from 1998 to 2007. Unfortunately, full epidemiological data were only available for 165 cases due to absence of a reliable registration system.

Results

A steady increase in the number of cases was detected, from 24 in 1998, peaking at 82 cases in 2005, followed by a gradual decline (though still high) with 68 cases in 2006 and 51 cases in 2007. Male/female ratio was 1.35/1 (p > 0.05). The occupational exposure to asbestos was 13.9%. Residential exposure plays a major role in two regions, Helwan and Shoubra (27.3% and 20.6% respectively), while in Upper and Lower Egypt the level was 12.7% and 17.5% respectively. Kaplan-Meier survival for sex, residence and the pathological types epithelioid, biphasic and sarcomatoid was insignificant. The median survival for different grades and treatment modalities was significant (P < 0.001).

Conclusions

There was a steady increase in the incidence of MPM from 1998 to 2005 followed by a decline during 2006-2007. Mesothelioma in Egypt is mainly concentrated in areas of high environmental pollution. The decline within the last 2 years may be attributed to recent strict industrial preventive measures. However, a better environmental control programme would benefit Egypt.     

Oxidant and antioxidant of arylesterase and paraoxonase as biomarkers in patients with hepatitis C virus

ObjectivesOxidative stress plays a role in the pathogenesis in patients with HCV infection. The objective of this study was to evaluate oxidant and antioxidant biomarkers in patients with HCV.Design and methodsSerum malonaldehyde (MDA) and nitric oxide (NO) levels and the activities of myeloperoxidase (MPO), arylesterase (AE) and paraoxonase-1 (PON1) were determined in 23 chronic and 21 cirrhotic patients with HCV and 21 healthy subjects.ResultsCirrhotic patients with HCV had higher serum NO level and MPO activity while lower AE and PON1 activities than the chronic. Significant inverse correlation was observed between MDA and PON1 activity in patients with HCV. The most significant HCV biomarker was MDA, AE, NO and PON1. The best combined ones for sensitivity, specificity were MDA + albumin, PON1 + AST, and PON1 + albumin.ConclusionsThe use of the MDA, MPO, AE, NO and PON1 as biomarkers might be useful tools, helping in the monitoring of patients with HCV.     

Attenuation of morphine tolerance and dependence by aminoguanidine in mice

The effect of aminoguanidine, an inducible nitric oxide synthase (iNOS) inhibitor, on morphine-induced tolerance and dependence in mice was investigated in this study. Acute administration of aminoguanidine (20 mg/kg, p.o.) did not affect the antinociceptive effect of morphine (10 mg/kg, s.c.) as measured by the hot plate test. Repeated administration of aminoguanidine along with morphine attenuated the development of tolerance to the antinociceptive effect of morphine. Also, the development of morphine dependence as assessed by naloxone-precipitated withdrawal manifestations was reduced by co-administration of aminoguanidine. The effect of aminoguanidine on naloxone-precipitated withdrawal was enhanced by concurrent administration of the non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist, dizocilpine (0.25 mg/kg, i.p.) or the non-specific nitric oxide synthase (NOS) inhibitor, l-N(G)-nitroarginine methyl ester (l-NAME; 5 mg/kg, i.p.) and antagonized by concurrent administration of the nitric oxide (NO) precursor, l-arginine (50 mg/kg, p.o.). Concomitantly, the progressive increase in NO production, but not in brain glutamate level, induced by morphine was inhibited by repeated administration of aminoguanidine along with morphine. Similarly, co-administration of aminoguanidine inhibited naloxone-induced NO overproduction, but it did not inhibit naloxone-induced elevation of brain glutamate level in morphine-dependent mice. The effect of aminoguanidine on naloxone-induced NO overproduction was potentiated by concurrent administration of dizocilpine or l-NAME and antagonized by concurrent administration of l-arginine. These results provide evidence that blockade of NO overproduction, the consequence of NMDA receptor activation, by aminoguanidine, via inhibition of iNOS, can attenuate the development of morphine tolerance and dependence.     

Electromotor activity of the cecum and ascending colon: the concept of 'individual pacemakers'

BACKGROUND/AIMS: The cecum is described as differing anatomically from the ascending colon (AC); yet their similarity or difference in terms of motile activity has not been studied sufficiently. The cecum is separated from the AC by the cecocolonic junction (CCJ) which contains a cecocolonic sphincter. We assumed that the motile activity of the AC is different from that of the cecum and hypothesized that both the AC and the cecum might have different pacemakers which initiate the motile activity. This hypothesis was investigated in the current study. METHODS: The study was performed in 10 subjects (mean age 41.6 +/- 12.8 SD years; 7 women) during the repair of huge abdominal incisional hernias. The electric activity was recorded from 2 monopolar electrodes applied each to the cecum, CCJ and AC. The CCJ was then anesthetized by xylocaine and the electric waves of the cecum, CCJ and AC were registered after 10 and 90 min. The test was repeated using normal saline instead of xylocaine. RESULTS: Electric waves were recorded from the cecum, CCJ and AC in the form of monophasic pacesetter (PPs) and action potentials (APs). The PPs occurred regularly and the APs randomly. The frequency, amplitude and conduction velocity of the waves recorded from the CCJ and AC had higher readings than those from the cecum (p < 0.05). The CCJ and AC showed similar frequency and conduction velocity (p > 0.05). Ten minutes after CCJ anesthetization, electric waves were recorded from the cecum but not from the CCJ or AC; however, electric activity returned after 90 min. Saline injection did not affect the electric activity of the cecum, CCJ and AC. CONCLUSION: The electric wave parameters of the cecum differed from those of the CCJ and AC, suggesting that the motile activity of the CCJ and AC is not a continuation of the motile activity of the cecum and that it might be evoked by 2 different pacemakers. The similarity in frequency and conduction velocity of electric waves of the CCJ and AC, however, most likely denotes that the AC waves are a continuation of those of the CCJ, and that both are evoked by the same pacemaker probably located in the CCJ. The higher amplitude of cecal waves might be due to the thicker cecal musculature compared to that of the AC.