Caveolin-1 and -2 regulate cell motility in castration-resistant prostate cancer

Toyoharu Kamibeppu, Koji Yamasaki, Kozue Nakahara, Takahiro Nagai, Naoki Terada, Hiromasa Tsukino, Shoichiro Mukai, Toshiyuki Kamoto Department of Urology, Faculty of Medicine, University of Miyazaki, Kiyotake, Japan Background: Caveolin (Cav)-1 and Cav-2 are cell membrane proteins, which are structural proteins of caveolae and are reported to be positive regulators of cell survival and metastasis in prostate cancer (PC). In a previous study, we reported that elevated levels of Cav-1 and Cav-2 were significantly associated with PC progression. However, their functions in PC have not yet been clarified. In this study, we examined the function of Cav-1 and Cav-2 in PC cell invasiveness and motility.Materials and methods: We introduced Cav-1- and Cav-2-specific small interfering into PC3 cells to knock-down (KD) both molecules. We also performed cell proliferation assay, wound healing assay, migration assay, and invasion assay using PC3 cells and compared the results between Cav-1-KD, Cav-2-KD, and negative control PC3 cells. In addition, we performed real-time quantitative PCR (RT-qPCR) and RT2 Profiler PCR Array analysis to identify factors influencing migration.Results: We observed no significant difference in the proliferative and invasive activities of Cav-1-KD and Cav-2-KD PC3 cells; however, the cell motility was significantly decreased compared with negative control PC3 cells. RT-qPCR revealed that the expression of vimentin and N-cadherin was downregulated in Cav-1-KD PC3 cells. In addition, PCR array revealed a decreased expression of MGAT5, MMP13, and MYCL in Cav-1-KD PC3 and ETV4, FGFR4, and SRC in Cav-2-KD PC3.Conclusion: Cav-1 and Cav-2 may positively contribute to the upregulation of castration-resistant PC cell migration. Cav-induced regulation of several molecules including vimentin, N-cadherin, MGAT5, MMP13, MYCL, ETV4, FGFR4, and SRC may have an important role in PC3 cell motility. However, further examination will be required. Keywords: caveolin-1, caveolin-2, CRPC, cell motilit

Salmonella in healthy pigs: prevalence, serotype diversity and antimicrobial resistance observed during 1998–1999 and 2004–2005 in Japan

To determine prevalence, serotype diversity and antimicrobial resistance of Salmonella in healthy pigs, faecal samples from 6771 pigs on 73 farms collected during 1998–1999 and 2004–2005 were examined. Salmonella isolates were serotyped and tested for susceptibility to 22 antimicrobials: benzylpenicillin, ampicillin, amoxicillin, cefazolin, cephaloridine, gentamicin, kanamycin, streptomycin, fradiomycin, colistin, tetracycline, chlortetracycline, oxytetracycline, chloramphenicol, thiamphenicol, sulfadimethoxine, sulfamethoxazole, sulfamethoxypyridazine, trimethoprim, sulfamethoxazole/trimethoprim, norfloxacin and ofloxacin. Farm-level and pig-level Salmonella prevalences were 35·5% and 2·2% in 1998–1999, and 35·7% and 3·3% in 2004–2005. Prevalence by growth stage was 2·4% for sows, 3·3% for weaned pigs, 2·7% for fattening pigs and 3·8% for finishing pigs. The predominant serotypes identified were Agona (28·4%), Typhimurium (17·9%) and Infantis (16·4%) in 1998–1999, and Typhimurium (32·5%), Anatum (24·6%) and Infantis (13·5%) in 2004–2005. Compared with the 1998–1999 isolates, the 2004–2005 isolates showed significantly higher rates of resistance to all the antimicrobials except tetracyclines (P<0·01 to P<0·05) and resistance to ⩾2 antimicrobials [19·4% (13/67) vs. 39·7% (50/126), P<0·01]. This study provides national estimates of Salmonella prevalence in healthy pigs of different growth stages in Japan