Matteucinol combined with temozolomide inhibits glioblastoma proliferation, invasion, and progression: an in vitro, in silico, and in vivo study

Glioblastoma is the most prevalent and malignant brain tumor identified in adults. Surgical resection followed by radiotherapy and chemotherapy, mainly with temozolomide (TMZ), is the chosen treatment for this type of tumor. However, the average survival of patients is around 15 months. Novel approaches to glioblastoma treatment are greatly needed. Here, we aimed to investigate the anti-glioblastoma effect of the combination of matteucinol (Mat) (dihydroxyflavanone derived from Miconia chamissois Naudin) with the chemotherapeutic TMZ in vitro using tumor (U-251MG) and normal astrocyte (NHA) cell lines and in vivo using the chick embryo chorioallantoic membrane (CAM) assay. The combination was cytotoxic and selective for tumor cells (28 μg/mL Mat and 9.71 μg/mL TMZ). Additionally, the combination did not alter cell adhesion but caused morphological changes characteristic of apoptosis in vitro. Notably, the combination was also able to reduce tumor growth in the chick embryo model (CAM assay). The docking results showed that Mat was the best ligand to the cell death membrane receptor TNFR1 and to TNFR1/TMZ complex, suggesting that these two molecules may be working together increasing their potential. In conclusion, Mat-TMZ can be a good candidate for pharmacokinetic studies in view of clinical use for the treatment of glioblastoma.

Validation of tissue microarray technology in malignant peripheral nerve sheath tumours

BACKGROUND

It has been suggested that the donor tissue cores used in tissue microarrays (TMAs) may not be representative of the whole tissue section.

AIM

To validate the use of TMA technology in the study of malignant peripheral nerve sheath tumours (MPNSTs).

METHODS

A TMA was constructed containing five independent core biopsy samples of 14 formalin-fixed, paraffin-embedded MPNSTs. The immunohistochemical (IHC) results of the five cores from the same tissue block on TMA were compared with readings from whole sections using two antibodies: anti-Ki-67 and anti-S-100. Digital image analysis was performed to calculate the percentage of positive stain areas. The agreement between IHC results obtained with TMA cores and whole sections was assessed using the kappa statistic.

RESULTS

There was good to very good agreement between IHC results for whole and TMA sections from MPNSTs. In relation to S-100, very good agreement (92% agreement; kappa = 0.77) was observed using a minimum of four TMA cores. Staining results for Ki-67 from at least four readable TMA cores were the same as those for the whole section in 86% of cases, with good agreement, using weighted kappa statistics (kappa = 0.63).

CONCLUSIONS

This study indicates that the TMA technique can be used in the IHC study of MPNSTs, even with the use of heterogeneous markers such as S-100 protein.

The involvement of the chemokine receptor CXCR2 in neutrophil recruitment in LPS-induced inflammation and in Mycobacterium avium infection

Knockout mice for CXC receptor 2 (CXCR2) chemokine receptor were used to study the recruitment of neutrophils during acute and chronic inflammatory responses. When treated with lipopolysaccharide (LPS), either intraperitoneally or intratracheally, these animals had a significant reduction in the neutrophil recruitment in the first 24-48 h as compared with control mice. During 15 days of intraperitoneal infection by Mycobacterium avium, the knockout mice showed significantly reduced numbers of neutrophils in the peritoneal cavity as compared with the control mice. In contrast, the recruitment of neutrophils to the lungs during an aerogenic M. avium infection was not affected by the CXCR2 mutation throughout the 60 days of the study. Finally, we could not find any impact of the mutation on the mycobacterial growth of the infected animals. These findings indicate that CXCR2 may be essentially involved in acute inflammatory responses where an early and rapid recruitment of neutrophils is observed.

Effects of recombinant granulocyte-colony stimulating factor administration during Mycobacterium avium infection in mice

Granulocyte colony-stimulating factor (G-CSF) administration in vivo has been shown to improve the defence mechanisms against infection by different microbes. Here we evaluated a possible protective role of this molecule in a mouse model of mycobacterial infection. The administration of recombinant G-CSF promoted an extensive blood neutrophilia but failed to improve the course of Mycobacterium avium infection in C57Bl/6 or beige mice. G-CSF administration also failed to improve the efficacy of a triple chemotherapeutic regimen (clarithromycin + ethambutol + rifabutin). G-CSF treatment did not protect interleukin-10 gene disrupted mice infected with M. avium. Spleen cells from infected mice treated with G-CSF had a decreased priming for antigen-specific production of interferon gamma compared to control infected mice. Our data do not substantiate previous reports on the protective activity of G-CSF in antimycobacterial immunity using mouse models.

Modulation of neutrophil influx with cell adhesion molecule specific antibodies during nonspecific and immune mediated inflammatory reactions

Neutrophils are essential for the host defence against infection. However, neutrophils may also mediate damage namely during immune mediated pathologies. We therefore tested whether targeting of different cell adhesion molecules with specific monoclonal antibodies might reduce immune mediated neutrophil recruitment but spare the nonspecific accumulation of neutrophils that is essential for the resistance against acute infections. Neutrophil recruitment was induced by either intraperitoneal injection of casein as a nonspecific phlogistic agent or by i.p. injection of antigen in Mycobacterium bovis Bacille Calmette-Guérin (BCG) immune mice. Similar degrees of inhibition of neutrophil accumulation were observed in both models of inflammation with antibodies directed at CD11a, ICAM-1 and CD11b with the latter showing the most marked effects. Individual targeting of selectins was without effect in immune mediated responses whereas targeting of L or E selectin inhibited nonspecific recruitment of neutrophils. This was apparently not owing to a dosage effect nor to a kinetic difference. The inhibitory effect of anti-CD11b antibodies was most likely as a result of activation of circulating neutrophils rather than the blocking of receptor-ligand interactions. We were therefore unable to selectively abrogate immune mediated neutrophil recruitment with the use of the antibodies selected in this study.

Resistance of virulent Mycobacterium avium to gamma interferon-mediated antimicrobial activity suggests additional signals for induction of mycobacteriostasis

The cytokine gamma interferon (IFN-gamma) plays a major role in the control of Mycobacterium avium infections. We assessed whether the progressive growth of virulent strains of M. avium was associated with alterations in the production of this cytokine as evaluated by reverse transcription-PCR and detection of immunoreactive cytokine in the serum and in spleen homogenates. We found that IFN-gamma was induced during infection by a virulent strain of M. avium to similar or even higher extents than the levels found during infections by a less virulent strain whose growth was controlled. IFN-gamma produced during infection by both mycobacterial strains was partly derived from T cells and led to activation of macrophages, namely, those that were infected. Concomitant with the development of the infection with the virulent strain of M. avium there was an extensive depletion of lymphocytes in the spleen. Thymectomy alone promoted the proliferation of the virulent, but not of the less virulent, strain of M. avium. Our data indicate that virulent strains of M. avium resist the antimicrobial mechanisms of IFN-gamma-activated macrophages and raise the possibility that a second, T-cell-dependent signal is required for the effective control of mycobacterial replication inside macrophages.

Evaluation of esophageal motility in laryngectomized patients

Laryngectomy for treatment of laryngeal-pharyngeal carcinomas may impair the sensation in the larynx and epiglottis, with consequent impairment of esophageal motility. Our aim in the present study was to investigate the esophageal motility of laryngectomized patients. Esophageal manometry was performed on 17 patients submitted to laryngectomy 2 to 71 months (median 29 months) before the examination. Eleven were rehabilitated with esophageal voice and six could not speak. Ten swallows of a 5 ml bolus of water were recorded at the lower esophageal sphincter and at 5, 10 and 15 cm above it. The lower esophageal sphincter pressure was measured by the rapid pull-through method and the upper esophageal sphincter pressure by the station pull-through method. The results were compared with those obtained for a control group of 40 healthy volunteers. The amplitude of contractions was lower and the number of nonperistaltic contractions was higher in laryngectomized patients than in volunteers (P < 0.05). The duration of lower esophageal sphincter relaxation (7.4 +/- 1.5 s) was shorter in laryngectomized patients than in volunteers (8.8 +/- 1.6 s, P < 0.05). The upper esophageal sphincter pressure was lower (34.9 +/- 29.1 mm Hg) in laryngectomized patients than in volunteers (61.2 +/- 20.8 mm Hg, P < 0.05). There was no difference between groups in contraction duration or velocity, in the numbers of multipeaked or failed contractions, lower esophageal sphincter pressure or in the number of swallows followed by complete lower esophageal sphincter relaxation. In conclusion, laryngectomy causes esophageal motility impairment characterized by low contraction amplitude, nonperistaltic contraction and shorter lower esophageal sphincter relaxation duration.

Antinociceptive effect of intrathecal neostigmine evaluated in rats by two different pain models

The analgesic efficacy of cholinergic agonists and anticholinesterase agents has been widely recognized. The analgesic effect obtained by activating cholinergic mechanisms, however, seems to depend on the experimental pain model utilized for its evaluation. The antinociceptive effect of intraspinal neostigmine was examined in rats submitted concurrently to the tail flick and formalin tests. Neostigmine (8.25 and 16.5 nmol) produced a dose-dependent antinociceptive effect in the tail flick test (a model of phasic pain) and reduced the first phase (phasic pain) of the animal response to formalin also in a dose-dependent manner. The second phase (tonic pain) of the response to formalin, however, was slightly reduced after a longer period of time only by the higher dose of the anticholinesterase. The effect of neostigmine was not significantly different when the drug was injected into rats submitted exclusively to the tail flick test. The second phase of the animal response to formalin was slightly reduced by neostigmine (8.25 nmol) and strongly inhibited by the higher dose of the anticholinesterase when injection was made after the first phase. We conclude that phasic and tonic pain can both be controlled by high doses of neostigmine. In addition, we show that inhibition by a lower dose of neostigmine of the formalin-induced phasic pain did not prevent the subsequent occurrence of tonic pain produced by the irritant.