METHODS: PNMA5 mutants were generated through deletion or site-directed mutagenesis and transiently expressed in human cancer cell lines to investigate their role in apoptosis, subcellular localization, and potential interaction with MOAP-1 through apoptosis assays, fluorescence microscopy, and co-immunoprecipitation studies, respectively.
RESULTS: Over-expressed human PNMA5 exhibited nuclear localization pattern in both MCF-7 and HeLa cells. Deletion mapping and mutagenesis studies showed that C-terminus of PNMA5 is responsible for nuclear localization, while the amino acid residues (391KRRR) within the C-terminus of PNMA5 are required for nuclear targeting. Deletion mapping and co-immunoprecipitation studies showed that PNMA5 interacts with MOAP-1 and N-terminal domain of PNMA5 is required for interaction with MOAP-1. Furthermore, co-expression of PNMA5 and MOAP-1 in MCF-7 cells significantly enhanced chemo-sensitivity of MCF-7 to Etoposide treatment, indicating that PNMA5 and MOAP-1 interact synergistically to promote apoptotic signaling in MCF-7 cells.
CONCLUSIONS: Our results show that PNMA5 promotes apoptosis signaling in HeLa and MCF-7 cells and interacts synergistically with MOAP-1 through its N-terminal domain to promote apoptosis and chemo-sensitivity in human cancer cells. The C-terminal domain of PNMA5 is required for nuclear localization; however, both N-and C-terminal domains of PNMA5 appear to be required for pro-apoptotic function.
DESIGN: A prospective study.
SETTING: A tertiary hospital in Malaysia.
POPULATION: A cohort of 193 term nulliparous women with intact membranes.
METHODS: Prior to labour induction, cervical fluid was obtained via a vaginal speculum and tested for IGFBP-1, followed by TVUS and finally Bishop score. After each assessment the procedure-related pain was scored from 0 to 10. Cut-off values for Bishop score and cervical length were obtained from the receiver operating characteristic (ROC) curve. Multivariable logistic regression analysis was performed.
MAIN OUTCOMES MEASURES: Vaginal delivery and vaginal delivery within 24 hours of starting induction.
RESULTS: Bedside IGFBP-1 testing is better tolerated than Bishop score, but is less well tolerated than TVUS [median (interquartile range) of pain scores: 5 (4-5) versus 6 (5-7) versus 3 (2-3), respectively; P < 0.001]. IGFBP-1 independently predicted vaginal delivery (adjusted odds ratio, AOR 5.5; 95% confidence interval, 95% CI 2.3-12.9) and vaginal delivery within 24 hours of induction (AOR 4.9; 95% CI 2.1-11.6) after controlling for Bishop score (≥4 or ≥5), cervical length (≤29 or ≤27 mm), and other significant characteristics for which the Bishop score and TVUS were not predictive of vaginal delivery after adjustment. IGFBP-1 has 81% sensitivity, 59% specificity, positive and negative predictive values of 82 and 58%, respectively, and positive and negative likelihood ratios of 2.0 and 0.3 for vaginal delivery, respectively.
CONCLUSION: IGFBP-1 better predicted vaginal delivery than BS or TVUS, and may help guide decision making regarding labour induction in nulliparous women.
TWEETABLE ABSTRACT: IGFBP-1: a stronger independent predictor of labour induction success than Bishop score or cervical sonography.