Standardization of CTC AR-V7 PCR assay and evaluation of its role in castration resistant prostate cancer progression.

BACKGROUND: Castration resistant prostate cancer (CRPC) represents the most aggressive status of this neoplastic disease, also characterized by the absence of biomarkers predictive of clinical outcome. New drugs as abiraterone or enzalutamide, affecting androgen receptor pathway at different levels, inhibit the proliferative advantage of prostate cancer cells with important long term benefits. Despite the advantages of this second-generation androgen deprivation therapy (ADT), resistance mechanisms, primitive or acquired, often develop. The existence of androgen receptor (AR) splice variants (AR-Vs), in particular AR-V7 expression detected in circulating tumor cells (CTCs), represents an example of acquired resistance, as evidenced in preclinical and clinical studies. Recent studies also have suggested the role of AR-V7 as a prognostic biomarker in mCRPC. In this field, hot topics are the methodology used to isolate CTC and the assay for AR-V7 measurement. Our study aims to develop a standardized operating procedure (SOP) to evaluate AR-V7 in CRPC. METHOD: The application of a realized cell based Reference Sample as Standardized Quality Control tool for CTC-AR-V7 assay has been shown. Then the development, the performance evaluation and contextualization in a clinical setting of this standardized operating procedure (SOP) have been reported to evaluate the prognostic biomarker AR-V7 in metastatic prostate cancer. RESULTS AND CONCLUSIONS: The standardized procedure has high sensitivity and specificity and enables the detection and quantification of the spliced variant with respect to the full length AR (AR-FL) mRNA in CTC DNA purified from the blood of patients with CRPC. This procedure has been further validated in a consecutive series of patients with mCRPC, confirming its role as prognostic biomarker.

Human papillomavirus (HPV) detection in vaginal self-samples: evaluation of eNat® as an alternative suspension medium to ThinPrep®PreservCyt® for vaginal swabs.

Human Papillomavirus (HPV) testing on self-collected samples allows for improved coverage rates of cervical cancer (CC) screening programs. ThinPrep®PreservCyt® (HOLOGIC®, USA) medium is widely used for the suspension of cervical and vaginal self-samples. However, this medium is costly, toxic, and flammable, involving special handling procedures which make its use difficult in screening programs, particularly in low- and middle-income countries. This pilot study aimed to evaluate the analytical performance of eNat ® (Copan SpA), an alternative non-alcohol-based suspension medium, compared to ThinPrep®PreservCyt® (HOLOGIC®) for high-risk HPV (hrHPV) detection in vaginal self-collected swabs using three different real-time polymerase chain reaction (RT-PCR) HPV assays: Anyplex™II HPV28 (Seegene, Korea), Papilloplex® High Risk HPV (GeneFirst, UK), and HPV OncoPredict (Hiantis, Italy). 30 women, referred to colposcopy, were enrolled in this observational, prospective pilot study and asked to collect two vaginal self-taken samples, which were suspended in 5 mL of ThinPrep®PreservCyt® or eNat®. Nucleic acids were extracted from 200 µL using Microlab Nimbus platform (Seegene, Korea) and tested with the three different RT-PCR full-genotyping high-risk HPV assays. The HPV results of vaginal samples resuspended in the two different media were compared to those obtained from the reference clinician-collected cervical sample from the same woman. hrHPV detection in vaginal self-samples suspended in both media demonstrated a substantial agreement with cervical samples with the three assays under-investigation (0.667

Regulation of editing and expression of glutamate alpha-amino-propionic-acid (AMPA)/kainate receptors by antidepressant drugs.

BACKGROUND: Several reports have shown that the glutamatergic system is involved in both the pathogenesis of affective and stress-related disorders and in the action of antidepressant drugs. In particular, antidepressant treatment was shown to modulate expression and function of ionotropic glutamate receptors, to inhibit glutamate release and to restore synaptic plasticity impaired by stress. METHODS: We analyzed the mRNA expression and RNA editing of alpha-amino-propionic-acid (AMPA) and kainate (KA) receptor subunits, in the pre-frontal/frontal cortex (P/FC) and hippocampus (HI) of rats chronically treated with three different drugs: the selective serotonin (5-HT) reuptake inhibitor fluoxetine, the selective noradrenaline (NA) reuptake inhibitor reboxetine and the tricyclic antidepressant desipramine. RESULTS: Our data showed that fluoxetine and desipramine exerted moderate but selective effects on glutamate receptor expression and editing, while reboxetine appeared to be the drug that affects glutamate receptors (GluR) most. The most consistent effect, observed with pronoradrenergic drugs (desipramine and reboxetine), was a decrease of GluR3 expression both in P/FC and HI. Interestingly, in HI, the same drugs also decreased the editing levels of either the flip (desipramine) or flop (reboxetine) form of GluR3. CONCLUSIONS: Overall, these results point to specific and regionally discrete changes in the expression and editing level of glutamate receptors and, in particular, to a selective reduction of conductance for GluR3-containing receptors following treatment with antidepressant drugs. These data support the hypothesis that changes in glutamate neurotransmission are involved in the therapeutic effects induced by these drugs.

Glutamate receptor RNA editing: a molecular analysis of GluR2, GluR5 and GluR6 in human brain tissues and in NT2 cells following in vitro neural differentiation.

The properties of some glutamate receptors are modified by RNA editing. This post-transcriptional mechanism involves the enzymatic deamination of specific adenosines in the pre-mRNA of the glutamate receptors, performed by specific RNA adenosine deaminases (ADARs). This event gives rise to the substitution of a gene-encoded amino acid with a different one that modifies the physiological properties of the ion channel. Here we report an analysis of the editing levels of AMPA GluR2, and kainate GluR5 and GluR6 in a human teratocarcinoma cell line (NT2) during in vitro neural differentiation, in conjunction with an analysis of the expression levels of GluR and ADAR genes. The editing levels were analysed using a specific standardised assay based on sequence analysis. This assay can be performed on all editing sites with a high level of sensitivity and reproducibility. Whereas GluR gene expression increased during NT2 neural differentiation, the expression of ADAR genes may be detected at comparable levels even in undifferentiated NT2 cells, remaining relatively stable during the differentiation process. Furthermore, most of the glutamate receptor editing sites increased their editing levels during NT2 neural differentiation, suggesting that the level of ADAR mRNAs is not closely related to the variable editing levels detected in the GluRs analysed. In human brain tissues, the editing levels appeared finely modulated in the different areas, indicating the possible formation of ion channels with different functional properties, thus generating a complex tissue-specific regulation of receptors and modulation of excitatory stimuli.

Development of an allele-specific real-time PCR assay for discrimination and quantification of p63 R279H mutation in EEC syndrome.

The ectrodactyly-ectodermal dysplasia-clefting syndrome is a rare autosomal dominant disorder caused by heterozygous mutations in the p63 gene, a transcription factor belonging to the p53 family. The majority of cases of ectrodactyly-ectodermal dysplasia syndrome are caused by de novo mutations and are therefore sporadic in approximately 60% of patients. The substitution of arginine to histidine (R279H), due to a c.836G>A mutation in exon 7 of the p63 gene, represents 55% of the identified mutations and is considered a mutational hot spot. A quantitative and sensitive real-time PCR was performed to quantify both wild-type and R279H alleles in DNA extracted from peripheral blood and RNA from cultured epithelial cells. Standard curves were constructed for both wild-type and mutant probes. The sensitivity of the assay was determined by generating serial dilutions of the DNA isolated from heterozygous patients (50% of alleles mutated) with wild-type DNA, thus obtaining decreasing percentages of p63 R279H mutant allele (50%, 37.5%, 25%, 12.5%, 10%, 7.5%, 5%, 2.5%, and 0.0%). The assay detected up to 1% of the mutant p63. The high sensitivity of the assay is of particular relevance to prenatal diagnosis and counseling and to detect therapeutic effects of drug treatment or gene therapy aimed at reducing the amount of mutated p63.