Inhibitory effect of a Ras homologue member I on pancreatic cancer and its modulation on epithelium growth factor receptor-Ras-Raf-mitogen-activated protein kinase/extracellular regulated protein kinase/1/2 pathway.

OBJECTIVE: To investigate the regulation of epithelium growth factor receptor (EGFR), pan-Ras, and extracellular regulated protein kinase (ERK) with both a ras homologue member I (ARHI) suppression and epithelium growth factor (EGF) stimulation. METHODS: After identification and implication, the constructed plasmid pIRES2-EGFP-ARHI was transfected into Panc-1. The untransfected cell was also explored as controls. The growth curve was drawn to indicate the proliferation effect of ARHI. EGFR-ELISA was performed to investigate the expression of EGFR. Western blot analysis was used to investigate the expression of protein MAPK/ERK1/2, pan-Ras in Panc-1. RESULTS: The proliferation rate of Panc-1 was inhibited by ARHI compared with both empty plasmid and untransfected cell. The amount of EGFR was parallel in both transfected and untransfected cell but affected by EGF stimulation. The amount of pan-Ras was decreased after ARHI transfection. The optimum concentration of EGF effect on P-ERK was 50 ng/ml. CONCLUSION: Both ARHI and EGF play roles in the EGF-EGFR-Ras-Raf-MAPK/ERK1/2 pathway.

Preoperative sensitivity and specificity for early-stage ovarian cancer when combining cancer antigen CA-125II, CA 15-3, CA 72-4, and macrophage colony-stimulating factor using mixtures of multivariate normal distributions.

PURPOSE: In CA-125-based ovarian cancer screening trials, overall specificity and screening sensitivity of ultrasound after an elevated CA-125 exceeded 99.6% and 70%, respectively, thereby yielding a positive predictive value (PPV) exceeding 10%. However, sensitivity for early-stage disease was only 40%. This study aims to increase preoperative sensitivity for early-stage ovarian cancer while maintaining the annual referral rate to ultrasound at 2% by combining information across CA-125II, CA 15-3, CA 72-4, and macrophage colony-stimulating factor (M-CSF). For direct comparisons between marker panels, all sensitivity results correspond to a 98% fixed first-line specificity (referral rate 2%). PATIENTS AND METHODS: Logistic regression, classification tree, and mixture discriminant analysis (MDA) models were fit to a training data set of preoperative serum measurements (63 patients, 126 healthy controls) from one center. Estimates from the training set applied to an independent validation set (60 stage I to II patients, 98 healthy controls) from two other centers provided unbiased estimates of sensitivity. RESULTS: Preoperative sensitivities for early-stage disease of the optimal panels were 45% for CA-125II; 67% for CA-125II and CA 72-4; 70% for CA-125II, CA 72-4, and M-CSF; and 68% for all four markers (latter two results using MDA). CONCLUSION: Efficiently combining information on CA-125II, CA 72-4, and M-CSF significantly increased preoperative early-stage sensitivity from 45% with CA-125II alone to 70%, while maintaining 98% first-line specificity. Screening trials with these markers using MDA followed by referral to ultrasound may maintain previously high levels of specificity and PPV, while significantly increasing early-stage screening sensitivity. MDA is a useful, biologically justified method for combining biomarkers.