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.     

Molecular analysis of cell-free circulating DNA for the diagnosis of somatic mutations associated with resistance to tyrosine kinase inhibitors in non-small-cell lung cancer

In non-small-cell lung cancer, the molecular diagnosis of somatic mutations is instrumental for the choice of the most appropriate treatment. However, despite an initial response, resistance to tyrosine kinase inhibitors occurs and thereafter tumors progress. For this reason, next generation inhibitors able to overcome acquired resistances are currently in development. Therefore, the identification of the molecular determinants of resistance is needed to adapt treatment accordingly. The analysis of circulating cell-free tumor DNA represents a powerful tool to monitor the somatic changes induced by treatment. This review focuses on the most recent advantages in the diagnosis of acquired resistance in circulating cell-free tumor DNA and underlines the strategies ready to be translated in the clinical practice.     

Utility of history, examination and laboratory tests in screening those returning to Europe from the tropics for parasitic infection

OBJECTIVES: To examine the utility of the different elements of screening expatriates and travellers returned from the tropics for parasitic disease (exposure history, symptoms, examination and laboratory tests). METHODS: In phase 1 (conducted prospectively 1990-91), 1029 asymptomatic returnees had a detailed questionnaire and interview on risk-behaviour, physical examination and laboratory tests. In phase 2 (1997-98), 510 consecutive patients referred for routine screening (276 symptomatic and 234 asymptomatic) were screened with laboratory tests. RESULTS: Exposure history did not correlate reliably with parasite burden. In phase 1 physical examination revealed 387 abnormalities, only three of which indicated parasitic disease. Schistosomal serology was positive in 11% (CI 9-13) of these asymptomatic cases including patients with light or no reported freshwater exposure. Stool microscopy was positive in 19% (CI 16-22) of cases not correlated with reported eating habits, and eosinophilia was present in 8% (CI 6-10). In phase 2 reported symptoms did not correlate with parasitic disease. Schistosomiasis was present in 15% (CI 13-24) of asymptomatic and 18% (CI 13-22) of symptomatic individuals (OR 1.2 P = 0.46); stool microscopy was positive in 14% of both symptomatic and asymptomatic patients, and eosinophilia in 9% of symptomatic and 6% of asymptomatic individuals. CONCLUSION: Potentially serious asymptomatic infection is common in travellers. Detailed exposure history, symptom history and physical examination added little to detecting cases. Stool microscopy, schistosomal serology and eosinophil count all had good yield. Filarial serology had low yield in patients without eosinophilia.     

Bromocriptine does not alter growth hormone (GH) responsiveness to GH-releasing hormone in acromegaly

GHRH (100 micrograms) and TRH (200 micrograms) were administered to 24 active acromegalic patients before and during chronic bromocriptine (Br) treatment (Br, 10-15 mg/day for 3-5 months) to evaluate the possible effects of the dopamine agonist on GH release induced by these releasing hormones. Mean daily plasma GH levels were reduced by Br treatment from 34 +/- 40 (SD) to 16 +/- 19 ng/ml (P less than 0.01). No significant changes were found when comparing the GH response to GHRH as mean area under the response curve (nanograms per min/ml above the basal) (pretreatment, 5453 +/- 7843; during Br, 7017 +/- 12763 ng/ml . min), and as mean individual peak GH values (pretreatment, 130 +/- 148; during Br, 126 +/- 187 ng/ml) before and during treatment. The percentage GH increase (pretreatment, 340 +/- 354; during Br, 617 +/- 539%) was however significantly higher during Br. Br treatment significantly reduced the GH response to TRH in terms of mean of individual peak levels (from 136 +/- 134 to 60 +/- 52 ng/ml; P less than 0.01) and area under the response curve (from 3142 +/- 3998 to 1331 +/- 1646 ng/min . ml; P less than 0.01). However, the percentage GH increase was not significantly different (pretreatment, 486 +/- 729; during Br, 1059 +/- 1862%). When the patients were divided into Br responders, i.e. mean daily GH reduction during Br of at least 50% below baseline, and nonresponders, the initial response to GHRH was significantly higher in the latter group, but was unaffected by Br treatment in either group. On the contrary, the response to TRH, statistically significant initially only in the Br responder group, was reduced by Br treatment. We suggest that cells sensitive to Br and TRH but not to GHRH (lactotroph-like) and cells sensitive to GHRH but not to Br (pure somatotrophs) may coexist in GH-secreting adenomas.     

The global cardiovascular risk chart]

BACKGROUND: Risk charts, built through risk functions deriving from longitudinal studies, are used in order to identify individuals at high risk for cardiovascular disease. For this reason the function has been identified and the global cardiovascular risk chart of the CUORE Project has been prepared, using Italian data coming from different cohorts enrolled between the '80s and the '90s, whose risk factors had been collected by standardized procedures. METHODS: The following risk factors have been used: age (10-year period, 40-49, 50-59, 60-69 years), gender (men and women), systolic blood pressure (< or = 129, 130-149, 150-169, > or = 170 mmHg), serum cholesterol (< or = 173, 174-212, 213-251, 252-290, > or = 291 mg/dl), smoking habit (yes, no) and presence of diabetes (yes, no); the first coronary or cerebrovascular event in people aged 40-69 years with no other previous cardiovascular events was considered as endpoint; survival has been assessed up to December 1998. RESULTS: Out of 18,028 people aged 40-69 years with no previous cardiovascular events, 647 first major cardiovascular events have been identified and validated, 449 coronary and 198 cerebrovascular. Charts are divided according to men and women and to diabetics and non-diabetics respectively; the different colors represent the percent level of risk and go from light green (< 5% in 10 years for men, < 1% in 5 years for women), dark green (between 5 and 10% for men, between 1 and 3% for women), yellow (between 10 and 15% for men, between 3 and 5% for women), orange (between 15 and 20% for men, between 5 and 7% for women), red (between 20 and 30% for men, between 7 and 10% for women), violet (> 30% for men, > 10% for women). CONCLUSIONS: The risk charts were built with data collected in recent years on men and women with a median follow-up of 10 years for men and 5 years for women, considering the first major fatal or non-fatal cardiovascular event as endpoint. Such a tool is easy to be applied by general practitioners and cardiologists in order to achieve a fast and objective evaluation of global cardiovascular risk.     

The primary antibody response of malaria patients to Plasmodium falciparum sexual stage antigens which are potential transmission blocking vaccine candidates

Thirty serum samples collected from adult patients attending the Hospital for Tropical Diseases, London, with P. falciparum malaria, were studied. Sera were screened by indirect immunofluorescence for anti-gametocyte antibodies. Twelve of the serum samples taken from 14 patients with primary infections were found to have both IgM and IgG antibodies to gametocyte antigens and total Ig titres comparable with those of patients who had had previous malaria attacks. Sera of individuals from hyperendemic areas have been found to immunoprecipitate the 230 and 48/45 kD gametocyte surface antigens which are known targets of transmission blocking antibodies. To investigate the epitope specificity of the serum samples from our adult patients, competitive ELISAs with 3 monoclonal antibodies (MAbs) that block transmission and recognize different epitopes on the 48/45 Kd antigen, were carried out. Specific antibodies for these epitopes were found in 60% of the sera while nearly a third were able to inhibit the binding of at least two MAbs.     

Different growth factor activation in the right and left ventricles in experimental volume overload

Mechanical factors play a key role in activation of cardiac growth factor response in hemodynamic overload, and both cooperate in myocardial remodeling. The present study was performed to investigate whether a different growth factor response is activated in the right and left ventricles in aortocaval fistula and its effects on regional myocardial adaptation. Relations between regional growth factor expression (angiotensin II, insulin-like growth factor-I, and endothelin-1), myocyte shape changes, and collagen deposition were investigated at mRNA and peptide levels in adult pigs after the creation of an aortocaval fistula distal to the renal arteries (n=15) and in sham-operated animals (n=15). The role of angiotensin II was investigated by the administration of angiotensin-converting enzyme inhibitor or angiotensin II receptor antagonist. In the left ventricle, pure volume overload was accompanied by persistent increase of insulin-like growth factor-I mRNA expression, peptide concentration (2.2-fold versus sham at 3 months, P<0.05), and significant increase of myocyte length (+29% at 3 months, P<0.05). Conversely, the mixed pressure-volume overload faced by the right ventricle resulted in significant regional overexpression of all growth factors investigated (angiotensin II, insulin-like growth factor-I, and endothelin-1), with corresponding increase of myocyte diameter and length and collagen deposition (+117% at 3 months). Collagen accumulation in the right ventricle as well as the increase in right ventricular end-diastolic pressure at the 3-month observation were inhibited by angiotensin II antagonism. The left and right ventricles respond differently to aortocaval fistula, and local growth factor expression is closely related to the regional myocardial adaptation.