No abstract

MicroRNAs (miRNAs) are a class of small, non-coding RNA molecules that can regulate gene expression, thereby affecting crucial processes in cancer development. miRNAs offer great potential as biomarkers for cancer detection because of their remarkable stability in blood and their characteristic expression in different diseases. We investigated whether quantitative RT-PCR miRNA profiling on serum could discriminate between breast cancer patients and healthy controls. We performed miRNA profiling on serum from breast cancer patients, followed by construction of ROC (Receiver Operating Characteristic) curves to determine the sensitivity and specificity of the assay. We found that seven miRNAs (miR-10b, miR-21, miR-125b, miR-145, miR-155 miR-191 and miR-382) had different expression patterns in serum of breast cancer patients compared to healthy controls. ROC curve analyses revealed that three serum miRNAs could be valuable biomarkers for distinguishing BC from normal controls. Additionally, a combination of ROC curve analyses of miR-145, miR-155 and miR-382 showed better sensitivity and specificity of our assay. miRNA profiling in serum has potential as a novel method for breast cancer detection in the Mexican population.

No abstract

hPL is a member of an evolutionarily related gene family including hGH and hPRL. Expression of hPL is limited to the placenta but its physiological actions are far reaching. hPL has a direct somatotropic effect on fetal tissues, it alters maternal carbohydrate and lipid metabolism to provide for fetal nutrient requirements, and aids in stimulation of mammary cell proliferation. Two hPL genes (hPL3 and hPL4) encoding identical proteins are responsible for the production of up to 1-3 g PL hormone/day. Recent studies have characterized the regulatory controls of hPL expression. At the post transcriptional level, RNA stability may contribute to variable levels of hPL3 vs. hPL4 production. In addition, non-tissue-specific protein-promoter interactions involving the Sp1 transcription factor are necessary for hPL transcription initiation. A transcriptional enhancer located 3' to the hPL3 gene is responsible for the placenta-specific expression of this gene, while an additional enhancer may be located 3' to the hPl4 gene. The hPL enhancer is bound by multiple proteins including at least one placental specific protein that interacts with a TEF-1 motif. Therefore, enhancer-protein interactions most likely play a large part in the high levels of placenta-specific hPL expression.