Exosomal lncRNA-p21 levels may help to distinguish prostate cancer from benign disease

A symptom index for benign prostatic hyperplasia (BPH) was developed and validated by a multidisciplinary measurement committee of the American Urological Association (AUA). Validation studies were conducted involving a total of 210 BPH patients and 108 control subjects. The final AUA symptom index includes 7 questions covering frequency, nocturia, weak urinary stream, hesitancy, intermittence, incomplete emptying and urgency. On revalidation, the index was internally consistent (Cronbach's alpha = 0.86) and the score generated had excellent test-retest reliability (r = 0.92). Scores were highly correlated with subjects' global ratings of the magnitude of their urinary problem (r = 0.65 to 0.72) and powerfully discriminated between BPH and control subjects (receiver operating characteristic area 0.85). Finally, the index was sensitive to change, with preoperative scores decreasing from a mean of 17.6 to 7.1 by 4 weeks after prostatectomy (p < 0.001). The AUA symptom index is clinically sensible, reliable, valid and responsive. It is practical for use in practice and for inclusion in research protocols.

Exosomes are 40-100 nm membrane vesicles of endocytic origin secreted by most cell types in vitro. Recent studies have shown that exosomes are also found in vivo in body fluids such as blood, urine, amniotic fluid, malignant ascites, bronchoalveolar lavage fluid, synovial fluid, and breast milk. While the biological function of exosomes is still unclear, they can mediate communication between cells, facilitating processes such as antigen presentation and in trans signaling to neighboring cells. Exosome-like vesicles identified in Drosophila (referred to as argosomes) may be potential vehicles for the spread of morphogens in epithelia. The advent of current MS-based proteomic technologies has contributed significantly to our understanding of the molecular composition of exosomes. In addition to a common set of membrane and cytosolic proteins, it is becoming increasingly apparent that exosomes harbor distinct subsets of proteins that may be linked to cell-type associated functions. The secretion of exosomes by tumor cells and their implication in the transport and propagation of infectious cargo such as prions and retroviruses such as HIV suggest their participation in pathological situations. Interestingly, the recent observation that exosomes contain both mRNA and microRNA, which can be transferred to another cell, and be functional in that new environment, is an exciting new development in the unraveling exosome saga. The present review aims to summarize the physical properties that define exosomes as specific cell-type secreted membrane vesicles.

A subtraction cDNA library enriched for RNA sequences preferentially expressed in growth-arrested cells was prepared. Six cDNA clones were identified, varying in abundance from 2% to 0.0002% of the library and in size from 0.8 to 10 kb. The corresponding mRNAs are downregulated with different kinetics upon induction of growth by serum. The kinetics of induction after serum starvation and density-dependent inhibition of two of these growth-arrest-specific (gas) genes were investigated in more detail. Two cell lines transformed by viral onc genes did not express the two gas genes. The full-length cDNA for one gene has been sequenced and the protein product preliminarily characterized by in vitro translation.