Effects of siRNA-mediated silencing of Sal-like 4 expression on proliferation and apoptosis of prostate cancer C4-2 cells.

The aim of this study was to evaluate the effects of small interfering RNA (siRNA)-inhibited expression of the Sal-like 4 (SALL4) gene on the proliferation, colony formation, and apoptosis of prostate cancer C4-2 cells. C4-2 cells were cultured and divided into a si-SALL4 group, a negative control siRNA group, and a blank control group. SALL4 mRNA levels and protein expression were detected by real-time polymerase chain reaction and western blot, respectively. Changes in the cell proliferation and colony formation capacities were observed by using the MTS colorimetric method and colony formation assay, respectively. The influence of SALL4 on apoptosis was assessed with flow cytometry, and the expression of apoptosis-related proteins B-cell lymphoma 2 (Bcl-2) and bcl-like-protein 4 (Bax) were detected by western blot. The si-SALL4 group had significantly lower mRNA and protein levels of SALL4 as well as decreased proliferation and colony formation capacities than the negative control group (P < 0.05). There were significantly more apoptotic cells in the si-SALL4 group compared to the negative control (P < 0.05), and the expression of Bcl-2 and Bax decreased and increased, respectively, after treatment with si-SALL4. Silencing SALL4 expression by using siRNA technology inhibited the proliferation and colony formation of C4-2 cells, and promoted apoptosis likely mediated by Bcl-2 and Bax expression. These results provide experimental basis for further elucidating the role of SALL4 in prostate cancer cells.

In vivo determination of muscle-derived stem cells in rat corpus cavernosum.

The aim of this in vivo study was to determine the existence of muscle-derived stem cells (MDSCs) in rat corpus cavernosum. Immunohistochemical and RT-PCR analyses were performed to determine the expression of the stem cell markers (Sca-1, Oct4, and desmin) in Sprague-Dawley (SD) rats in different age groups (10 rats in each group). Sca-1 was mainly expressed in blood vessels and cavernous sinus and demonstrated primarily cytoplasmic staining. Desmin was expressed mainly in muscle tissues and staining occurred mainly in the cytoplasm but also partially in the nucleus. An extremely small amount of double-positive stained cells (Sca-1/desmin) were detected near the cavernous sinus. Expression of the markers was significantly and negatively correlated with the age of the rats (P < 0.05). The RT-PCR results showed that the expression levels of Sca-1 and desmin significantly decreased with age (P < 0.05). Correlation analysis indicated that the expression of Sca-1 and desmin were significantly and negatively correlated with the age of rats (r = -0.929, P < 0.05). The present study provides evidence for the existence of MDSCs in rat corpus cavernosum. MDSCs may have therapeutic potential in the treatment of organic erectile dysfunction.

Analysis of the genetic effects of CAPN1 gene polymorphisms on chicken meat tenderness.

The micromolar calcium-activated neutral protease gene (CAPN1) is a physiological candidate gene for meat tenderness. Four previously identified single nucleotide polymorphism (SNP) markers located within the CAPN1 gene were evaluated for their associations with variation in the meat tenderness of a Chinese indigenous chicken breed, a higher meat quality breed (i.e., Qingyuan partridge chicken), and the commercial Recessive White chicken breed. Warner-Bratzler shear force measurements were used to determine tenderness phenotypes for all animals; intramuscular fat (IMF) content and rate of water loss in the breast muscles were also measured. Genotyping was performed by the polymerase chain reaction-ligase detection reaction method. Polymorphisms were identified for all markers, except CAPN1 2546. The frequency of allele T was zero, and allele C was fixed for CAPN1 2546 in the studied populations. The SNP CAPN1 3535 in the CAPN1 gene was significantly associated with tenderness and other meat quality traits, where animals inheriting the AA genotype had smaller shear force values, lower water loss rates, and higher IMF contents. Moreover, H1 (AAA) was the most advantageous haplotype for meat tenderness. The results of this study confirm some previously documented associations. Furthermore, novel associations have been identified that, following validation in other populations, could be incorporated into breeding programs to improve meat quality.

Association of chicken growth hormone polymorphisms with egg production.

Growth hormone (GH) has diverse functions in animals, together with other hormones from the somatotropic axis. Here, chicken GH (cGH) was investigated in recessive white chickens and Qingyuan partridge chickens as a candidate gene affecting egg production traits. Chicken egg production traits were studied in association with 4 selected single nucleotide polymorphisms (T185G, G662A, T3094C, and C3199T). Genotyping was performed by the polymerase chain reaction-ligase detection reaction method. T185G was significantly associated with the egg production traits of body weight at first egg (BW), egg weight at first egg (EW), and the total egg production of 300-day old birds (EN 300). T3094C was also significantly associated with certain egg production traits; however, it affected the 2 breeds differently. Haplotypes of the 4 single nucleotide polymorphisms were also significantly associated with egg production traits of chicken age at first egg laying, BW, EW, and EN 300. H1H6 was the most advantageous diplotype for egg production. We putatively concluded that polymorphisms in the cGH gene and its haplotypes could be used as potential molecular markers for egg production traits to enhance the breeding programs of indigenous chickens.

Transcriptional co-activator PGC-1α gene is associated with chicken skeletal muscle fiber types.

The peroxisome proliferators-activated receptor-γ coactivator-1α (PGC-1α) is a candidate gene for meat quality traits because of its prominent role in muscle fiber type switching and determination. We investigated the effects of the PGC-1α gene on chicken skeletal muscle fiber type switching and on other meat quality traits. Single nucleotide polymorphisms were detected by PCR-SSCP and DNA sequencing, and then genotyping was performed by PCR-ligation detection reaction methods. Skeletal muscle fiber types, intramuscular fat content, shear forces, and water loss rate of the gastrocnemius lateralis muscle were measured in Qingyuan Partridge chickens and Recessive White chickens. Four SNPs, C171T in exon2, C384T in exon3, G646A in exon5, and A948G in exon8 were detected. Marker-trait association analysis indicated that G646A polymorphism was associated with skeletal myofiber type and that H1 (CCAA) was the most advantageous haplotype for skeletal myofiber type. We concluded that polymorphisms of the PGC-1α gene and their haplotypes are associated with chicken skeletal myofiber type traits.

miR-499A>G rs3746444 and miR-146aG>C expression and hepatocellular carcinoma risk in the Chinese population.

We conducted a case-control study of a possible association of miR-499A>G rs3746444 and miR-146aG>C rs2910164 with risk of hepatocellular carcinoma. Samples from 172 hepatocellular carcinoma patients and 185 cancer-free controls were collected from October 2008 to December 2011. PCR-RFLP analysis was performed to determine the polymorphisms in each individual. The MAFs of miR-146aG>C and miR-499A>G in controls were similar to that known from the SNP database, and frequencies of genotypes in controls were in line with Hardy-Weinberg equilibrium. We found that miR-499 AG was significantly associated with decreased risk for hepatocellular carcinoma when compared with miR-499 AA genotype (adjusted odds ration = 0.74, 95% confidence interval = 0.24-0.96). However, subjects carrying miR-146a GG had a non-significant 0.62-fold decreased risk of hepatocellular carcinoma. We did not find a significant association of miR-146aG>C rs2910164 and miR-499A>G rs3746444 polymorphisms with hepatocellular carcinoma risk in the Chinese population. Further investigations are warranted to clarify the relationship between miRNA polymorphisms and susceptibility to hepatocellular carcinoma risk in various ethnic populations.