Overexpression of certain transient receptor potential and Orai channels in prostate cancer is associated with decreased risk of systemic recurrence after radical prostatectomy.

BACKGROUND: Several studies had suggested the potential role of calcium signaling in prostate cancer (PCa) prognosis and agressiveness. We aimed to investigate selected proteins contributing to calcium (Ca2+ ) signaling, (Orai, stromal interaction molecule (STIM), and transient receptor potential (TRP) channels) and involved in cancer hallmarks, as independent predictors of systemic recurrence after radical prostatectomy (RP). METHODS: A case-control study including 112 patients with clinically localized PCa treated by RP between 2002 and 2009 and with at least 6-years' follow-up. Patients were divided into two groups according to the absence or presence of systemic recurrence. Expression levels of 10 proteins involved in Ca2+ signaling (TRPC1, TRPC4, TRPV5, TRPV6, TRPM8, STIM1, STIM2, Orai1, Orai2, and Orai3), were assessed by immunohistochemistry using tissue microarrays (TMAs) constructed from paraffin-embedded PCa specimens. The level of expression of the various transcripts in PCa was assessed using quantitative polymerase chain reaction (qPCR) analysis. RNA samples for qPCR were obtained from fresh frozen tissue samples of PCa after laser capture microdissection on RP specimens. Relative gene expression was analyzed using the 2-▵▵Ct method. RESULTS: Multivariate analysis showed that increased expression of TRPC1, TRPC4, TRPV5, TRPV6, TRPM8, and Orai2 was significantly associated with a lower risk of systemic recurrence after RP, independently of the prostate-specific antigen (PSA) level, percentage of positive biopsies, and surgical margin (SM) status (P = .007, P = .01, P < .001, P = .0065, P = .007, and P = .01, respectively). For TRPC4, TRPV5, and TRPV6, this association was also independent of Gleason score and pT stage. Moreover, overexpression of TRPV6 and Orai2 was significantly associated with longer time to recurrence after RP (P = .048 and .023, respectively). Overexpression of TRPC4, TRPV5, TRPV6, and Orai2 transcripts was observed in group R- (3.71-, 5.7-, 1.14-, and 2.65-fold increase, respectively). CONCLUSIONS: This is the first study to suggest the independent prognostic value of certain proteins involved in Ca2+ influx in systemic recurrence after RP: overexpression of TRPC1, TRPC4, TRPV5, TRPV6, TRPM8, and Orai2 is associated with a lower risk of systemic recurrence. TRPC4, TRPV5, and TRPV6 appear to be particularly interesting, as they are independent of the five commonly used predictive factors, that is, PSA, percentage of positive biopsies, SM status, Gleason score, and pT stage.

Evaluation of quantitative PCR for early diagnosis of Pseudomonas aeruginosa infection in cystic fibrosis: a prospective cohort study.

OBJECTIVES: Early detection of Pseudomonas aeruginosa lung positivity is a key element in cystic fibrosis (CF) management. PCR has increased the accuracy of detection of many microorganisms. Clinical relevance of P. aeruginosa quantitative PCR (qPCR) in this context is unclear. Our aim was to determine P. aeruginosa qPCR sensitivity and specificity, and to assess the possible time saved by qPCR in comparison with standard practice (culture). METHODS: A multicentre cohort study was conducted over a 3-year period in 96 patients with CF without chronic P. aeruginosa colonization. Sputum samples were collected at each visit. Conventional culture and two-step qPCR (oprL qPCR and gyrB/ecfX qPCR) were performed for 707 samples. The positivity criteria were based on the qPCR results, defined in a previous study as follow: oprL qPCR positivity alone if bacterial density was <730 CFU/mL or oprL qPCR combined with gyrB/ecfX qPCR if bacterial density was ≥730 CFU/mL. RESULTS: During follow up, 36 of the 96 patients with CF were diagnosed on culture as colonized with P. aeruginosa. This two-step qPCR displayed a sensitivity of 94.3% (95% CI 79.7%-98.6%), and a specificity of 86.3% (95% CI 83.4%-88.7%). It enabled P. aeruginosa acquisition to be diagnosed earlier in 20 patients, providing a median detection time gain of 8 months (interquartile range 3.7-17.6) for them. CONCLUSIONS: Implementing oprL and gyrB/ecfX qPCR in the management of patients with CF allowed earlier detection of first P. aeruginosa lung positivity than culture alone.