Prostate-specific antigen is currently the only protein biomarker routinely used as a diagnostic tool for early detection and treatment monitoring of prostate cancer. However, it remains questionable whether prostate-specific antigen-based screening can sensitively and selectively identify the presence and progression status of primary and metastatic prostate cancers. Hence, the purpose of this study was to identify potential biomarker candidates in the secretome of primary and metastatic prostate cancer cells by using a combination of global and targeted proteomics. Quantitative comparisons among secretome proteins derived from androgen-responsive primary cancer cells (P-22Rv1), androgen-irresponsive bone metastatic cancer cells (M-PC-3), and noncancerous prostate cells (N-PNT2) were performed using 2-dimensional image-converted analysis of liquid chromatography and mass spectrometry followed by in silico selection selected reaction monitoring analysis. Mediator of RNA polymerase II transcription subunit 13-like, insulin-like growth factor-binding protein 2, and hepatocyte growth factor were identified as highly secreted proteins from P-22Rv1 cells compared with N-PNT2 cells. Prostate-associated microseminoprotein, proactivator polypeptide, collagen-α-1 (VI) chain, and neuropilin-1 were identified as predominantly secreted proteins in M-PC-3 cells compared with N-PNT2 cells. These proteins in biological fluids are considered to be candidate biomarkers of primary and/or metastatic prostate cancer.
Enterovirus 71 (EV71), one of the major causative agents for hand, foot and mouth disease (HFMD), is sometimes associated with severe central nervous system diseases. In 1997, in Malaysia and Japan, and in 1998 in Taiwan, there were HFMD epidemics involving sudden deaths among young children, and EV71 was isolated from the HFMD patients, including the fatal cases. The nucleotide sequences of each EV71 isolate were determined and compared by phylogenetical analysis. EV71 strains from previously reported epidemics belonged to genotype A-1, while those from recent epidemics could be divided into two genotypes, A-2 and B. In Malaysia, genotype A-2 was more prevalent, while in Japan and Taiwan, B genotype was more prevalent. Two isolates from fatal cases in Malaysia and one isolate from a fatal case in Japan were genotype A-2. However, all isolates from three fatal cases in Taiwan belonged to genotype B. The severity of the HFMD did not link directly to certain genotypes of EV71.