AKAP2-anchored protein phosphatase 1 controls prostatic neuroendocrine carcinoma cell migration and invasion.

Prostate cancer (PC) is the second leading cause of cancer-related death in men. The growth of primary prostate cancer cells relies on circulating androgens and thus the standard therapy for the treatment of localized and advanced PC is the androgen deprivation therapy. Prostatic neuroendocrine carcinoma (PNEC) is an aggressive and highly metastatic subtype of prostate cancer, which displays poor prognosis and high lethality. Most of PNECs develop from prostate adenocarcinoma in response to androgen deprivation therapy, however the mechanisms involved in this transition and in the elevated biological aggressiveness of PNECs are poorly defined. Our current findings indicate that AKAP2 expression is dramatically upregulated in PNECs as compared to non-cancerous prostate tissues. Using a PNEC cell model, we could show that AKAP2 is localized both intracellularly and at the cell periphery where it colocalizes with F-actin. AKAP2 and F-actin interact directly through a newly identified actin-binding domain located on AKAP2. RNAi-mediated silencing of AKAP2 promotes the phosphorylation and deactivation of cofilin, a protein involved in actin turnover. This effect correlates with a significant reduction in cell migration and invasion. Co-immunoprecipitation experiments and proximity ligation assays revealed that AKAP2 forms a complex with the catalytic subunit of protein phosphatase 1 (PP1) in PNECs. Importantly, AKAP2-mediated anchoring of PP1 to the actin cytoskeleton regulates cofilin dephosphorylation and activation, which, in turn, enhances F-actin dynamics and favors migration and invasion. In conclusion, this study identified AKAP2 as an anchoring protein overexpressed in PNECs that controls cancer cell invasive properties by regulating cofilin phosphorylation

Identification of MGMT Downregulation Induced by miRNA in Glioblastoma and Possible Effect on Temozolomide Sensitivity

Glioblastoma multiforme (GBM) remains one of the tumors with the worst prognosis. In recent years, a better overall survival (OS) has been described in cases subjected to Gross Total Resection (GTR) that were presenting hypermethylation of Methylguanine-DNA methyltransferase (MGMT) promoter. Recently, also the expression of specific miRNAs involved in MGMT silencing has been related to survival. In this study, we evaluate MGMT expression by immunohistochemistry (IHC), MGMT promoter methylation and miRNA expression in 112 GBMs and correlate the data to patients' clinical outcomes. Statistical analyses demonstrate a significant association between positive MGMT IHC and the expression of miR-181c, miR-195, miR-648 and miR-767.3p between unmethylated cases and the low expression of miR-181d and miR-648 and between methylated cases and the low expression of miR-196b. Addressing the concerns of clinical associations, a better OS has been described in presence of negative MGMT IHC, in methylated patients and in the cases with miR-21, miR-196b overexpression or miR-767.3 downregulation. In addition, a better progression-free survival (PFS) is associated with MGMT methylation and GTR but not with MGMT IHC and miRNA expression. In conclusion, our data reinforce the clinical relevance of miRNA expression as an additional marker to predict efficacy of chemoradiation in GBM

Identification of the first case of germline duplication of BRCA1 exon 13 in an Italian family

In this work we report for the first time a family in Italy with the BRCA1 ins6kbEx13 mutation, a recurrent founder mutation originating from northern Britain. After the initial identification of exon 13 duplication by multiplex ligation-dependent probe amplification (MLPA assay), we confirmed the identity of the alteration with the previously published BRCA1 ins6kbEx13 mutation, by mutation specific PCR and RT-PCR assays and by haplotype analysis. As rarely reported previously, the MLPA assay was also used to examine DNA from formalin fixed paraffin embedded (FFPE) normal tissues of other affected subjects in the family and it was the only effective method to perform a complete segregation analysis of the BRCA1 ins6kbEx13 mutation in the family. A combination of different approaches including MLPA analysis, haplotype analysis and LOH study on tumor samples of all the affected members allowed to reassess the maternal transmission of the mutation expected by the pedigree analysis. Moreover, detailed morphological analysis of breast cancers of BRCA1 ins6kbEx13 mutation carriers demonstrated a rare histological variant of breast carcinomas that has never been described in patients carrying BRCA1 mutations. Our study confirms the MLPA technique as a reliable and effective method for a primary screening for BRCA1 rearrangements also by using FFPE tissues and strongly suggests that histo-pathological, immunonohistochemical and molecular information from FFPE tumor tissues should be more often considered and integrated into routine diagnostic practice of hereditary tumors