Real time quantitative PCR (qPCR) is the method of choice for miRNA expression studies. For relative quantification of miRNAs, normalization to proper reference genes is mandatory. Currently, no validated reference genes for miRNA qPCR in prostate cancer are available. In this study, the expression of four putative reference genes (hsa-miR-16, hsa-miR-130b, RNU6-2, SNORD7) was examined with regard to their use as normalizer. After SNORD7 was already shown an inappropriate reference gene in preliminary experiments using total RNA pools, we studied the expression of the putative reference genes in tissue and normal adjacent tissue sample pairs from 76 men with untreated prostate carcinoma collected after radical prostatectomy. hsa-miR-130b and RNU6-2 showed no significantly different expression between the matched malignant and non-malignant tissue samples, whereas hsa-miR-16 was significantly underexpressed in malignant tissue. Softwares geNorm and Normfinder predicted hsa-miR-130b and the geometric mean of hsa-miR-130b and RNU6-2 as the most stable reference genes. Normalization of the four miRNAs hsa-miR-96, hsa-miR-125b, hsa-miR-205, and hsa-miR-375, which were previously shown to be regulated, shows that normalization to hsa-mir-16 can lead to biased results. We recommend using hsa-miR-130b or the geometric mean of hsa-miR-130b and small RNA RNU6-2 for normalization in miRNA expression studies of prostate cancer.
Aged ; Bias (Epidemiology) ; Carcinoma/diagnosis/*genetics/pathology ; Diagnostic Errors/prevention & control ; Gene Expression Profiling ; Gene Expression Regulation, Neoplastic ; Humans ; Male ; MicroRNAs/genetics/*metabolism ; Middle Aged ; Polymerase Chain Reaction ; Prostatic Neoplasms/diagnosis/*genetics/pathology ; *Reference Standards

OBJECTIVEProstate cancer (PCa) is a major health concern. Calliandra portoricensis (CP) is traditionally known for its analgesic, anti-ulcerogenic and anticonvulsant properties. However, its antiproliferative properties for PCa still need to be investigated.

METHODSAntioxidant activities of CP were determined by 1,1-diphenyl-2-picryhydrazyl (DPPH) and hydroxyl (OH(-)) radicals-scavenging methods. PC-3 and LNCaP (androgen-refractory and androgen-dependent PCa-derived cell lines) were cultured and treated with CP (10, 50 and 100 μg/mL). Effects of CP on cells were determined by cytotoxicity assay (lactate dehydrogenase, LDH) and viability assay (sodium 3'-[1-(phenylaminocarbonyl)-3,4-tetrazolium]-bis (4-methoxy-6-nitro) benzene sulfonic acid hydrate, XTT). DNA fragmentation was detected by cell death detection enzyme-linked immunosorbent assay plus kit. CP was tested as an inhibitor of angiogenesis using chicken chorioallantoic membrane (CAM) assay.

RESULTSCP showed significant scavenging of DPPH and OH(-) radicals. CP significantly (P<0.05) inhibited lipid peroxidation in a dose-dependent manner. Precisely, CP (10, 50 and 100 μg/mL) inhibited PC-3 and LNCaP growth by 7%, 74% and 92%, and 27%, 73%, and 85% respectively at 48 h. CP had low toxicity in vitro at its half inhibitory concentration dose. Detection of cell death induced by CP at 50 μg/mL showed higher enrichment factors in LNCaP (7.38±0.95) than PC-3 (3.48±0.55). Also, treatment with CP (50 μg/mL) significantly reduced network of vessels in CAM, suggesting its antiangiogenic potential.

CONCLUSIONCalliandra portoricensis elicited antioxidant, antiangiogenic and antiproliferative effects in PCa cells.

Angiogenesis Inhibitors ; pharmacology ; Animals ; Antineoplastic Agents, Phytogenic ; pharmacology ; Antioxidants ; pharmacology ; Fabaceae ; Humans ; Male ; Plant Extracts ; pharmacology ; Plant Roots ; Prostatic Neoplasms ; drug therapy ; pathology ; Rats ; Rats, Wistar