A novel capillary nano-immunoassay for assessing androgen receptor splice variant 7 in plasma. Correlation with CD133 antigen expression in circulating tumor cells. A pilot study in prostate cancer patients.

PURPOSE: Androgen receptor (AR) splice variant 7 (AR-V7) has been related with both a higher risk of prostate cancer (PC) progression and differential responsiveness to hormonal agents versus chemotherapy. The objective of this study was to investigate the feasibility of a novel capillary nano-immunoassay in assessing AR-V7 in plasma from PC patients. METHODS: Patients with either localized or advanced PC were included in the study. Assessment of AR-V7 in plasma was performed through a capillary nano-immunoassay platform. Correlation with clinical data, stem cell biomarkers (such as CD133+), AR amplification and PTEN status was identified. RESULTS: The study included 72 PC patients. AR-V7 signal was detected in 21 (29%) patients: 17 (81%) had a Gleason score ≥7, 15 (71%) castration-resistant prostate cancer (CRPC), 18 (86%) metastatic disease and PSA (median) high than AR-V7 negative (p < 0.05). CD133 was expressed in 69 (96%) patients. The median CD133+ expression in circulating tumor cells CTCs was higher among the 21 AR-V7 positive cases versus AR-V7 negative (7 vs. 3). Androgen Receptor and PTEN fluorescence in situ hybridization (FISH) on CD133+ captured cells were performed: 37 cases showed ≥four CD133+ CTCs, of which 81% showed an increased AR copy number. This percentage was similar in both AR-V7-positive and AR-V7-negative patients. A total of 68% of the cases showed deletion of PTEN: 70% were ARV-7 positive vs. 67%, which were AR-V7 negative. CONCLUSIONS: Assessing the presence of AR-V7 in plasma from PC patients is feasible by a novel capillary nano-immunoassay. AR-V7 was observed in 29% of the tumors and is more frequent in aggressive tumors.

Deregulation of microRNA expression in the different genetic subtypes of multiple myeloma and correlation with gene expression profiling.

Specific microRNA (miRNA) signatures have been associated with different cytogenetic subtypes in acute leukemias. This finding prompted us to investigate potential associations between genetic abnormalities in multiple myeloma (MM) and singular miRNA expression profiles. Moreover, global gene expression profiling was also analyzed to find correlated miRNA gene expression and select miRNA target genes that show such correlation. For this purpose, we analyzed the expression level of 365 miRNAs and the gene expression profiling in 60 newly diagnosed MM patients, selected to represent the most relevant recurrent genetic abnormalities. Supervised analysis showed significantly deregulated miRNAs in the different cytogenetic subtypes as compared with normal PC. It is interesting to note that miR-1 and miR-133a clustered on the same chromosomal loci, were specifically overexpressed in the cases with t(14;16). The analysis of the relationship between miRNA expression and their respective target genes showed a conserved inverse correlation between several miRNAs deregulated in MM cells and CCND2 expression level. These results illustrate, for the first time, that miRNA expression pattern in MM is associated with genetic abnormalities, and that the correlation of the expression profile of miRNA and their putative mRNA targets is useful to find statistically significant protein-coding genes in MM pathogenesis associated with changes in specific miRNAs.

Influence of protoporphyrin IX amino acid substituents on affinity to human breast adenocarcinoma MCF-7 cells.

The ability of protoporphyrin IX (PP IX) to enter neoplastic cells is used for diagnosis and photodynamic therapy. We present here the effects of PP IX and three amino acid derivatives on MCF-7 cell viability. The fluorescence of each substance was examined using confocal microscopy. Our results show that diarginine diprotoporphyrinate (PP(Arg)2) has satisfactory fluorescence to evaluate the rate of accumulation within cells. We have determined the times at which the accumulation begins and reaches a plateau, as well as cellular localization of PP(Arg)2 in MCF-7 cells.