Anti-miR21 oligonucleotide enhances chemosensitivity of T98G cell line to doxorubicin by inducing apoptosis

Various signal transduction pathways seem to be involved in chemoresistance mechanism of glioblastomas (GBMs). miR-21 is an important oncogenic miRNA which modulates drug resistance of tumor cells. We analyzed the expression of 5 miRNAs, previously found to be dysregulated in high grade gliomas, in 9 pediatric (pGBM) and in 5 adult (aGBM) GBMs. miR-21 was over-expressed, with a significant difference between pGBMs and aGBMs represented by a 4 times lower degree of expression in the pediatric compared to the adult series (p = 0.001). Doxorubicin (Dox) seems to be an effective anti-glioma agent with high antitumor activity also against glioblastoma stem cells. We therefore evaluated the chemosensitivity to Dox in 3 GBM cell lines (A172, U87MG and T98G). Dox had a cytotoxic effect after 48 h of treatment in A172 and U87MG, while T98G cells were resistant. TUNEL assay verified that Dox induced apoptosis in A172 and U87MG but not in T98G. miR-21 showed a low basal expression in treated cells and was over-expressed in untreated cells. To validate the possible association of miR-21 with drug resistance of T98G cells, we transfected anti-miR-21 inhibitor into the cells. The expression level of miR-21 was significantly lower in T98G transfected cells (than in the parental control cells). Transfected cells showed a high apoptotic rate compared to control after Dox treatment by TUNEL assay, suggesting that combined Dox and miR-21 inhibitor therapy can sensitize GBM resistant cells to anthracyclines by enhancing apoptosis.

Successful treatment of metastatic βHCG-secreting germ cell tumor occurring 3 years after total resection of a pineal mature teratoma

Patients diagnosed with intracranial teratoma are at risk for developing a recurrent malignant germ cell tumor. We describe a 14-year-old boy initially diagnosed with a mature teratoma in the pineal region that recurred as a metastatic beta-human chorionic gonadotropin (βHCG)-secreting germ cell tumor 3 years after gross total resection. A surveillance brain MRI scan during follow-up demonstrated multiple lesions within the ventricular and subependymal area infiltrating the brain parenchyma along with concomitant elevated levels of βHCG in both the serum and cerebrospinal fluid. The patient underwent chemotherapy with PEI (cis-platinum, etoposide, ifosfamide) followed by radiation therapy according to the SIOP CNS GCT protocol. The patient is currently alive without evidence of disease 35 months after starting therapy.

CONCLUSIONS

A careful and long-term follow-up including scheduled tumor markers as well as surveillance MRI scans is required for patients with intracranial teratoma in an effort to detect and diagnose recurrent malignant disease, especially since multimodal therapy provides the potential for long-term cure.

Genome-wide copy number analysis in pediatric glioblastoma multiforme

Glioblastoma (GBM) is a very aggressive and lethal brain tumor with poor prognosis. Despite new treatment strategies, patients' median survival is still less than 1 year in most cases. Few studies have focused exclusively on this disease in children and most of our understanding of the disease process and its clinical outcome has come from studies on malignant gliomas in childhood, combining children with the diagnosis of GBM with other pediatric patients harboring high grade malignant tumors other than GBM. In this study we investigated, using array-CGH platforms, children (median age of 9 years) affected by GBM (WHO-grade IV). We identified recurrent Copy Number Alterations demonstrating that different chromosome regions are involved, in various combinations. These observations suggest a condition of strong genomic instability. Since cancer is an acquired disease and inherited factors play a significant role, we compared for the first time the constitutional Copy Number Variations with the Copy Number Alterations found in tumor biopsy. We speculate that genes included in the recurrent 9p21.3 and 16p13.3 deletions and 1q32.1-q44 duplication play a crucial role for tumorigenesis and/or progression. In particular we suggest that the A2BP1 gene (16p13.3) is one possible culprit of the disease. Given the rarity of the disease, the poor quality and quantity of bioptic material and the scarcity of data in the literature, our findings may better elucidate the genomic background of these tumors. The recognition of candidate genes underlying this disease could then improve treatment strategies for this devastating tumor.

Low-dose cisplatin-etoposide regimen for patients with optic pathway glioma: a report of four cases and literature review

Optic pathway gliomas (OPGs) account for 5% of all childhood brain tumors. For years it has been discussed which was the best method of examining tumor progression when the magnetic resonance imaging (MRI) scan does not change. The role of chemotherapy in their treatment still remains controversial. We treated four consecutive patients affected by progressive OPG with lower cumulative doses of cisplatin/etoposide. The extension of disease was assessed by brain MRI scan. A complete ophthalmologic examination was performed. Ototoxicity was monitored. Our OPG patients had reduced visual acuity (VA) and/or visual field (VF) regardless of the MRI evaluation. All patients showed rapid visual recovery with improvement both in VA and in VF. At the time of writing, after a median follow-up of 34 months, all patients were alive and free from disease progression. Our results confirm the effectiveness and the low-toxicity profile of the cisplatin/etoposide regimen for treatment of children affected by OPG. We suggest that VA and VF can be considered as the most accurate parameters for defining the start of chemotherapy and tumor response.

Pharmacological modulation of blood-brain barrier increases permeability of doxorubicin into the rat brain

Our group recently demonstrated in a rat model that pretreatment with morphine facilitates doxorubicin delivery to the brain in the absence of signs of increased acute systemic toxicity. Morphine and other drugs such as dexamethasone or ondansetron seem to inhibit MDR proteins localized on blood-brain barrier, neurons and glial cells increasing the access of doxorubicin to the brain by efflux transporters competition. We explored the feasibility of active modification of the blood-brain barrier protection, by using morphine dexamethasone or ondansetron pretreatment, to allow doxorubicin accumulation into the brain in a rodent model. Rats were pretreated with morphine (10 mg/kg, i.p.), dexamethasone (2 mg/kg, i.p.) or ondansetron (2 mg/kg, i.p.) before injection of doxorubicin (12 mg/kg, i.p.). Quantitative analysis of doxorubicin was performed by mass spectrometry. Acute hearth and kidney damage was analyzed by measuring doxorubicin accumulation, LDH activity and malondialdehyde plasma levels. The concentration of doxorubicin was significantly higher in all brain areas of rats pretreated with morphine (P < 0.001) or ondansetron (P < 0.05) than in control tissues. The concentration of doxorubicin was significantly higher in cerebral hemispheres and brainstem (P < 0.05) but not in cerebellum of rats pretreated with dexamethasone than in control tissues. Pretreatment with any of these drugs did not increase LDH activity or lipid peroxidation compared to controls. Our data suggest that morphine, dexamethasone or ondansetron pretreatment is able to allow doxorubicin penetration inside the brain by modulating the BBB. This effect is not associated with acute cardiac or renal toxicity. This finding might provide the rationale for clinical applications in the treatment of refractory brain tumors and pave the way to novel applications of active but currently inapplicable chemotherapeutic drugs.

Changes in transcutaneous oxygen partial pressure as an index of response to inhaled methacholine in asthmatic patients

Bronchoconstriction and hypoxemia have been reported to occur during airway challenges, but the correlation between changes in forced expiratory volume in 1 s (FEV1) and transcutaneous oxygen partial pressure (tcPO2) during methacholine provocation tests has not yet been established (to our knowledge). In 15 symptom-free atopic asthmatic patients and 5 normal subjects, variations in tcPO2 and FEV1 were simultaneously measured during inhalation of doubling methacholine concentrations; the drug concentrations causing a 20 percent decrease in control FEV1 and tcPO2 (PC20FEV1 and PC20tcPO2, respectively) were subsequently calculated. In patients, geometric mean PC20FEV1 and PC20TcPO2 were 1.31 (range, 0.16 to 5.19) and 1.26 (range, 0.29 to 5.82) mg/ml, respectively. In addition, in six patients, methacholine-induced fall in tcPO2 was accompanied by similar changes in arterial PO2. Methacholine inhalation caused no change in tcPO2 or FEV1 in normal subjects. The independent effects of deep breath tests and bronchoconstriction on PC20tcPO2 were studied in five patients challenged on two separate occasions, with and without FEV1 assessment; in these patients, PC20tcPO2 were similar on both the study days. The results indicate that, in asthmatic patients, methacholine-induced bronchoconstriction causes parallel decreases in FEV1 and tcPO2. The tcPO2 monitoring may serve as a tool in the assessment of airway hyperreactivity when active patient's cooperation is scarce.

[Pneumoperitoneum in preparation for surgery of large ventral hernia]

Reparative surgery of ventral hernia may be relatively simple or, on the other hand, the surgeon may be confronted with a number of tactical and technical problems. Many of these are caused by the "loss of the right of domicile". In order to avoid this particular condition it is useful to resort to preoperative pneumoperitoneum. This method entails the gradual and progressive introduction of air into the peritoneal cavity. In this way abdominal capacity is increased and it is therefore possible to re-insert all the viscera into their natural cavities avoiding all the harmful consequences for respiratory and cardio-circulatory organs following forced replacement. Preoperative pneumo-peritoneum is a relatively well consolidated surgical technique in large scale eventration. The methods is simple to perform and has a low incidence of complications.

[Progressive pneumoperitoneum in the preparation for surgical intervention for voluminous ventral hernias]

The paper report three patients suffering from voluminous ventral hernias who were treated using progressive pneumoperitoneum as a preparative method prior to reparative surgery. On the basis of the results obtained, the authors sustain the rationality, safety and efficacy of the procedure, in particular given its ability to reestablish good respiratory and circulatory function in those cases where the latter were severely affected by hernia. Since this method needs a longer application time and therefore involves a greater economic burden, pneumoperitoneum should probably be reserved for selected cases, and alternative techniques should be used in patients where hernia is more easily resolved.

Influence of inspiratory flow rate on the bronchial response to ultrasonic mist of distilled water in asthmatic patients

In an attempt to evaluate the influence of inspiratory flow rate on the sensitivity of the bronchial challenge with ultrasonic mist of distilled water (UMDW), we studied 8 symptom-free asthmatic patients who inhaled 60 liters of UMDW at a flow rate of either 0.35 or 1.2 1/s on two separate occasions. Tidal volume and the total duration of the respiratory cycle were kept constant during all inhalation tests. The bronchial response was assessed in terms of percent changes of baseline airway conductance. The results demonstrate that the mean bronchial response after 0.35 1/s UMDW inhalation was significantly greater than after 1.2 1/s inhalation of comparable doses of UMDW. Furthermore, 3 patients who developed a significant bronchoconstriction after 0.35 1/s UMDW inhalation showed only a mild, not significant bronchial response when the mist was inhaled at 1.2 1/s. We conclude that the sensitivity of the UMDW challenge is increased if the agent is inhaled during slow, tidal breathing.

Effect of aminophylline aerosol on the bronchial response to ultrasonic mist of distilled water in asthmatic patients

To ascertain whether inhaled aminophylline was effective in preventing the bronchial response induced by inhalating of an ultrasonic mist of distilled water (UMDW), we examined 8 asthmatic patients who had previously been shown to be reactive to this agent. Patients were given either 30 mg aminophylline or saline placebo aerosols followed by inhalation of 60 liters of UMDW; measurements of specific airway conductance (sGaw) were made before and after aminophylline or saline administration and after UMDW challenge. UMDW consistently induced a significant decrease in sGaw in all patients; however, in our subjects as a group, the degree of UMDW-induced bronchoconstriction was significantly less after premedication with aminophylline aerosol than after saline (p less than 0.01). Our results suggest that aminophylline is effective in preventing UMDW-induced bronchoconstriction; the possible relationships between bronchial response to UMDW and its modulation by inhaled aminophylline are discussed.