Combined epidermal growth factor receptor and Beclin1 autophagic protein expression analysis identifies different clinical presentations, responses to chemo- and radiotherapy, and prognosis in glioblastoma.

Dysregulated EGFR in glioblastoma may inactivate the key autophagy protein Beclin1. Each of high EGFR and low Beclin1 protein expression, independently, has been associated with tumor progression and poor prognosis. High (H) compared to low (L) expression of EGFR and Beclin1 is here correlated with main clinical data in 117 patients after chemo- and radiotherapy.

Anisakid Nematodes as Possible Markers to Trace Fish Products.

In this work a total of 949 fish samples were analysed for the identification of nematode larvae belonging to the Anisakidae family. Biomolecular application for the identification of Anisakidae larvae can be an optimal instrument for the traceability of fish products, described on the Reg. EC 178/2002.

Combined EGFR and autophagy modulation impairs cell migration and enhances radiosensitivity in human glioblastoma cells.

Glioblastoma (GBM) remains the most aggressive and lethal brain tumor due to its molecular heterogeneity and high motility and invasion capabilities of its cells, resulting in high resistance to current standard treatments (surgery, followed by ionizing radiation combined with Temozolomide chemotherapy administration). Locus amplification, gene overexpression, and genetic mutations of epidermal growth factor receptor (EGFR) are hallmarks of GBM that can ectopically activate downstream signaling oncogenic cascades such as PI3K/Akt/mTOR pathway. Importantly, alteration of this pathway, involved also in the regulation of autophagy process, can improve radioresistance in GBM cells, thus promoting the aggressive phenotype of this tumor.

Emerging roles of microRNA in modulating cell-death processes in malignant glioma.

MicroRNAs (miRNAs) are small noncoding RNA molecules that regulate protein expression by cleaving or repressing the translation of target mRNAs. In mammals, their function mainly represses the mRNA transcripts via imperfect complementary sequences in the 3'UTR of target mRNAs. Several miRNAs have been recently reported to be involved in modulation of different genes in tumors, including glioblastoma, the most frequent brain tumor in adults.

microRNA-17 regulates the expression of ATG7 and modulates the autophagy process, improving the sensitivity to temozolomide and low-dose ionizing radiation treatments in human glioblastoma cells.

ATG7 is a key autophagy-promoting gene that plays a critical role in the regulation of cell death and survival of various cell types. We report here that microRNAs (miRNAs), a class of endogenous 22-24 nucleotide noncoding RNA molecules able to affect stability and translation of mRNA, may represent a novel mechanism for regulating ATG7 expression and therefore autophagy. We demonstrated that ATG7 is a potential target for miR-17, and this miRNA could negatively regulate ATG7 expression, resulting in a modulation of the autophagic status in T98G glioblastoma cells.

Autophagy and ionizing radiation in tumors: the "survive or not survive" dilemma.

Autophagy is a so-called "self-eating" system responsible for degrading long-lived proteins and cytoplasmic organelles, whose products are recycled to maintain cellular homeostasis. This ability makes autophagy a good candidate for a survival mechanism in response to several stresses, including the tumor cell transformation. In particular, recent studies suggested that autophagy functions as a pro-death mechanism within different tumor contexts.

Different involvement of autophagy in human malignant glioma cell lines undergoing irradiation and temozolomide combined treatments.

Glioblastoma (GB) has a poor prognosis, despite current multimodality treatment. Beside surgical resection, adjuvant ionizing radiation (IR) combined with Temozolomide (TMZ) drug administration is the standard therapy for GB. This currently combined radio-chemotherapy treatment resulted in glial tumor cell death induction, whose main molecular death pathways are still not completely deciphered.

Silencing of cellular prion protein (PrPC) expression by DNA-antisense oligonucleotides induces autophagy-dependent cell death in glioma cells.

Malignant gliomas are the most common and lethal primary central nervous system neoplasms. Several intriguing lines of evidence have recently emerged indicating that the cellular prion protein (PrPC) may exert neuro- and cyto-protective functions: PrPC overexpression protects cultured neurons and also tumor cell lines exposed to various pro-apoptotic stimuli while, on the contrary, PrPC silencing sensitizes Adriamycin-resistant human breast carcinoma cells to TRAIL-mediated cell death. In order to determine if PrPC is involved in the resistance of glial tumors to cell death, the effects of cellular prion protein downregulation by antisense approach were investigated in different human malignant glioma cell lines.

Gene expression analysis of an EGFR indirectly related pathway identified PTEN and MMP9 as reliable diagnostic markers for human glial tumor specimens.

In this study the mRNA levels of five EGFR indirectly related genes, EGFR, HB-EGF, ADAM17, PTEN, and MMP9, have been assessed by Real-time PCR in a panel of 37 glioblastoma multiforme specimens and in 5 normal brain samples; as a result, in glioblastoma, ADAM17 and PTEN expression was significantly lower than in normal brain samples, and, in particular, a statistically significant inverse correlation was found between PTEN and MMP9 mRNA levels. To verify if this correlation was conserved in gliomas, PTEN and MMP9 expression was further investigated in an additional panel of 16 anaplastic astrocytoma specimens and, in parallel, in different human normal and astrocytic tumor cell lines. In anaplastic astrocytomas PTEN expression was significantly higher than in glioblastoma multiforme, but no significant correlation was found between PTEN and MMP9 expression.

The doppel (Dpl) protein influences in vitro migration capability in astrocytoma-derived cells.

Doppel (Dpl) protein is the paralogue of the cellular prion (PrP(C)) protein. In humans, Dpl is expressed almost exclusively in testis where it is involved in spermatogenesis. Recently, the protein has been described to be ectopically expressed in astrocytomas and its potential association to the brain tumor malignancy progression has been advanced.

Altered cellular distribution and sub-cellular sorting of doppel (Dpl) protein in human astrocytoma cell lines.

Doppel, a prion-like protein, is a GPI-membrane anchored protein generally not expressed in the Central Nervous System (CNS) of different mammalian species, including human. Nevertheless, in astrocytomas, a particular kind of glial tumors, the doppel encoding gene (PRND) is over-expressed and the corresponding protein product (Dpl) is ectopically localized in the cytoplasm of the tumor cells. In this study we have analysed the sub-cellular localization of Dpl using double-immunofluorescence staining and confocal microscopy examinations in two astrocytoma-derived human cell lines (IPDDC-A2 and D384-MG).