miR-18b overexpression identifies mantle cell lymphoma patients with poor outcome and improves the MIPI-B prognosticator

Recent studies show that mantle cell lymphoma (MCL) express aberrant miRNA profiles, however, the clinical effect of miRNA expression has not previously been examined and validated in prospective, large, homogenously treated cohorts. We analyzed diagnostic MCL samples from the Nordic MCL2 and MCL3 clinical trials, in which all patients had received Rituximab-high-dose cytarabin alternating with Rituximab-maxiCHOP, followed by BEAM and autologous stem cell support. We performed genome-wide miRNA microarray profiling of 74 diagnostic MCL samples from the MCL2 trial (screening cohort). Differentially expressed miRNAs were re-analyzed by qRT-PCR. Prognostic miRNAs were validated by qRT-PCR in diagnostic MCL samples from 94 patients of the independent MCL3 trial (validation cohort). Three miRNAs (miR-18b, miR-92a, miR-378d) were significantly differentially expressed in patients who died from MCL in both the screening- and the validation cohort. MiR-18b was superior to miR-92a and miR-378d in predicting high risk. Thus, we generated a new MIPI-B-miR prognosticator, combining expression-levels of miR-18b with MIPI-B data. This prognosticator improved identification of high risk patients compared to MIPI-B with regard to cause-specific survival (P=0.015), overall survival (P=0.006) and progression-free survival (P<0.001). Transfection of two MCL cell lines with miR-18b decreased their proliferation rate without inducing apoptosis, suggesting miR-18b may render MCL cells resistant to chemotherapy by decelerating cell proliferation. Thus, we conclude that overexpression of miR-18b identifies patients with poor prognosis in two large prospective MCL cohorts and adds prognostic information to MIPI-B. MiR-18b may reduce the proliferation rate of MCL cells as a mechanism of chemoresistance

The effect of adenovirus-mediated gene expression of FHIT in small cell lung cancer cells

The candidate tumor suppressor fragile histidine traid (FHIT) is frequently inactivated in small cell lung cancer (SCLC). Mutations in the p53 gene also occur in the majority of SCLC leading to the accumulation of the mutant protein. Here we evaluated the effect of FHIT gene therapy alone or in combination with the mutant p53-reactivating molecule, PRIMA-1(Met)/APR-246, in SCLC. Overexpression of FHIT by recombinant adenoviral vector (Ad-FHIT)-mediated gene transfer in SCLC cells inhibited their growth by inducing apoptosis and when combined with PRIMA-1(Met)/APR-246, a synergistic cell growth inhibition was achieved