Current updates on the role of reactive oxygen species in bladder cancer pathogenesis and therapeutics.

Bladder cancer (BCa) is the fourth most common urological malignancy in the world, it has become the costliest cancer to manage due to its high rate of recurrence and lack of effective treatment modalities. As a natural byproduct of cellular metabolism, reactive oxygen species (ROS) have an important role in cell signaling and homeostasis. Although up-regulation of ROS is known to induce tumorigenesis, growing evidence suggests a number of agents that can selectively kill cancer cells through ROS induction. In particular, accumulation of ROS results in oxidative stress-induced apoptosis in cancer cells. So, ROS is a double-edged sword. A modest level of ROS is required for cancer cells to survive, whereas excessive levels kill them. This review summarizes the up-to-date findings of oxidative stress-regulated signaling pathways and transcription factors involved in the etiology and progression of BCa and explores the possible therapeutic implications of ROS regulators as therapeutic agents for BCa.

Differential expression of microRNAs may regulate pollen development in Brassica oleracea.

MicroRNAs (miRNAs) are a class of non-coding endogenous negative regulators that regulate gene expression at both the transcriptional and post-transcriptional levels. However, little is known about the expression characteristics of miRNAs during pollen development in Brassica oleracea. In this study, five known and three novel miRNAs were identified and their expression patterns were compared in the flower buds of B. oleracea using stem-loop reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time PCR. The results revealed that the eight miRNAs were constantly expressed during pollen development but exhibited different expression patterns during the five developmental stages of the flower buds between the cytoplasmic male sterile (CMS) line and its fertile maintainer. The highest miRNA expression levels occurred at the uninucleate microspore stage in the fertile line Bo01-12B and at the bicellular pollen stage in the CMS line Bo01-12A. Potential target genes for the miRNAs were predicted and analyzed, and suggested that miRNAs are involved in the regulation of target genes related to pollen development. The results of this study further our understanding of the regulatory role of miRNAs in pollen development.

Growth hormone secretory profiles: variation on consecutive nights.

To evaluate the reproducibility of overnight growth hormone (GH) testing and the effect of daytime administration of levodopa and clonidine on overnight GH secretion, we examined consecutive 12-hour overnight GH profiles of 48 short subjects, ages 5 to 16 years, who had GH stimulation testing with levodopa and clonidine. In six subjects (12%) the overnight pool GH concentration on the second night increased by greater than 100% from the first-night result (night-to-night changes of +1.2 to +5.2 ng/ml). In the remaining subjects, night-to-night changes in pool GH concentrations ranged from -1.2 to +1.8 ng/ml (-60% to +88% changes from the first night value). Night-to-night changes were less than 25% of the first-night value in 17 subjects (35%), 25% to 50% in 18 subjects (38%), and 50% to 100% in 7 subjects (15%). Night-to-night changes in pool GH concentrations correlated with differences in peak nighttime GH concentrations but not with differences in duration of observed sleep. There was no discernible effect of daytime levodopa-clonidine administration on overnight pool GH concentrations. These results demonstrate the potential for night-to-night variation in overnight GH profiles and suggest the need for some means of confirming that overnight GH testing reflects normal physiologic GH secretion. Without such confirmation, the results from a single overnight GH profile should be interpreted with caution.