Matrix metalloproteinase-9 is involved in chronic lymphocytic leukemia cell response to fludarabine and arsenic trioxide

16 p.-1 tab.-11 fig.Background: Matrix metalloproteinase-9 (MMP-9) contributes to chronic lymphocytic leukemia (CLL) pathology by regulating cell migration and preventing spontaneous apoptosis. It is not known if MMP-9 is involved in CLL cell response to chemotherapy and we address this in the present study, using arsenic trioxide (ATO) and fludarabine as examples of cytotoxic drugs. Methods: We used primary cells from the peripheral blood of CLL patients and MEC-1 cells stably transfected with an empty vector or a vector containing MMP-9. The effect of ATO and fludarabine was determined by flow cytometry and by the MTT assay. Expression of mRNA was measured by RT-PCR and qPCR. Secreted and cell-bound MMP-9 was analyzed by gelatin zymography and flow cytometry, respectively. Protein expression was analyzed by Western blotting and immunoprecipitation. Statistical analyses were performed using the two-tailed Student’s t-test. Results: In response to ATO or fludarabine, CLL cells transcriptionally upregulated MMP-9, preceding the onset of apoptosis. Upregulated MMP-9 primarily localized to the membrane of early apoptotic cells and blocking apoptosis with Z-VAD prevented MMP-9 upregulation, thus linking MMP-9 to the apoptotic process. Culturing CLL cells on MMP-9 or stromal cells induced drug resistance, which was overcome by anti-MMP-9 antibodies. Accordingly, MMP-9-MEC-1 transfectants showed higher viability upon drug treatment than Mock-MEC-1 cells, and this effect was blocked by silencing MMP-9 with specific siRNAs. Following drug exposure, expression of anti-apoptotic proteins (Mcl-1, Bcl-xL, Bcl-2) and the Mcl-1/Bim, Mcl-1/Noxa, Bcl-2/Bax ratios were higher in MMP-9-cells than in Mock-cells. Similar results were obtained upon culturing primary CLL cells on MMP-9. Conclusions: Our study describes for the first time that MMP-9 induces drug resistance by modulating proteins of the Bcl-2 family and upregulating the corresponding anti-apoptotic/pro-apoptotic ratios. This is a novel role for MMP-9 contributing to CLL progression. Targeting MMP-9 in combined therapies may thus improve CLL response to treatment.This work was supported by grants SAF2012-31613 (AGP) and RTICC (Red Temática de Investigación Cooperativa en Cáncer) RD12/0036/0061 (AGP), from the Ministry of Economy and Competitiveness (MINECO), Spain; S2010/BMD-2314-Neoplasbim (AGP) from the Comunidad de Madrid/European Union; and by a grant from the Fundaci?n Puerta de Hierro, Madrid (JAGM). IAJ and EB were were supported by the Junta de Ampliación de Estudios program, CSIC/EU, Spain.Peer reviewe

Healthy life expectancy and the correlates of self-rated health in Bangladesh in 1996 and 2002

BACKGROUND: Life expectancy (LE) at birth has increased steadily in Bangladesh since its independence. When people live longer, quality of life becomes a central issue. This study examines whether healthy life expectancy (HLE) at ages 15, 25, 35, and 45 is keeping pace with LE at those ages between 1996 and 2002. It also seeks to investigate the correlates of self-rated health (SRH) in 1996 and 2002. METHODS: We used data from the World Values Survey conducted in 1996 and 2002 among individuals 15 years and older. The Sullivan method was used to compute HLE. Socio-demographic differences and their association with different states of health were examined by chi-square and Pearson’s correlation tests. Multiple linear regression models were fitted to examine the correlates of SRH. RESULTS: The results show that perceived health improved between 1996 and 2002. For males, statistically significant increases in the expected number of years lived in good SRH were found. Proportionally, in 2002, both males and females at ages 15, 25, 35 and 45 expected more life years in good health and fewer life years in fair and poor health than did their counterparts in 1996. Comparatively, males expected fewer life years spent in good health but a much larger proportion of expected life in good health than did females. Finally, in multivariate analyses, life satisfaction was the only factor found to be significantly and positively associated with SRH for males and females in both years, although in both years the association was much more pronounced for females than for males. CONCLUSION: This study documented changes in HLE during 1996-2002. Women outlive men, but they have a lower quality of life and are more likely to live a greater part of their remaining life in poor SRH. Life satisfaction as well as other significant factors associated with SRH should be promoted, with special attention given to women, to improve healthy life expectancy and the quality of life of the Bangladeshi people

Critical assessment of automated flow cytometry analysis techniques

Traditional methods for flow cytometry (FCM) data processing rely on subjective manual gating. Recently, several groups have developed computational methods for identifying cell populations in multidimensional FCM data. The Flow Cytometry: Critical Assessment of Population Identification Methods (FlowCAP) challenges were established to compare the performance of these methods on two tasks: (i) mammalian cell population identification, to determine whether automated algorithms can reproduce expert manual gating and (ii) sample classification, to determine whether analysis pipelines can identify characteristics that correlate with external variables (such as clinical outcome). This analysis presents the results of the first FlowCAP challenges. Several methods performed well as compared to manual gating or external variables using statistical performance measures, which suggests that automated methods have reached a sufficient level of maturity and accuracy for reliable use in FCM data analysis