Fibroblast growth factors (FGF) and their high-affinity receptors (FGFR) represent an extensive cellular growth and survival system. Aim of this study was to evaluate the contribution of FGF/FGFR-mediated signals to the malignant growth of non-small cell lung cancer (NSCLC) and to assess their potential as targets for therapeutic interventions. Multiple FGFR mRNA splice variants were coexpressed in NSCLC cells (n = 16) with predominance of FGFR1. Accordingly, both expression of a dominantnegative FGFR1 (dnFGFR1) IIIc-green fluorescent protein fusion protein and application of FGFR small-molecule inhibitors (SU5402 and PD166866) significantly reduced growth, survival, clonogenicity, and migratory potential of the majority of NSCLC cell lines. Moreover, dnFGFR1 expression completely blocked or at least significantly attenuated s.c. tumor formation of NSCLC cells in severe combined immunodeficient mice. Xenograft tumors expressing dnFGFR1 exhibited significantly reduced size and mitosis rate, enhanced cell death, and decreased tissue invasion. When FGFR inhibitors were combined with chemotherapy, antagonistic to synergistic in vitro anticancer activities were obtained depending on the application schedule. In contrast, simultaneous blockage of FGFR-and epidermal growth factor receptor-mediated signals exerted synergistic effects. In summary, FGFRmediated signals in cooperation with those transmitted by epidermal growth factor receptor are involved in growth and survival of human NSCLC cells and should be considered as targets for combined therapeutic approaches.
We compared invasive cervical cancer (ICC) incidence rates in Europe, South Africa, Latin and North America among women living with HIV who initiated antiretroviral therapy (ART) between 1996 and 2014. We analyzed cohort data from the International Epidemiology Databases to Evaluate AIDS (IeDEA) and the Collaboration of Observational HIV Epidemiological Research in Europe (COHERE) in EuroCoord. We used flexible parametric survival models to determine regional ICC rates and risk factors for incident ICC. We included 64,231 women from 45 countries. During 320,141 person‐years (pys), 356 incident ICC cases were diagnosed (Europe 164, South Africa 156, North America 19 and Latin America 17). Raw ICC incidence rates per 100,000 pys were 447 in South Africa (95% confidence interval [CI]: 382–523), 136 in Latin America (95% CI: 85–219), 76 in North America (95% CI: 48–119) and 66 in Europe (95% CI: 57–77). Compared to European women ICC rates at 5 years after ART initiation were more than double in Latin America (adjusted hazard ratio [aHR]: 2.43, 95% CI: 1.27–4.68) and 11 times higher in South Africa (aHR: 10.66, 95% CI: 6.73–16.88), but similar in North America (aHR: 0.79, 95% CI: 0.37–1.71). Overall, ICC rates increased with age (>50 years vs. 16–30 years, aHR: 1.57, 95% CI: 1.03–2.40) and lower CD4 cell counts at ART initiation (per 100 cell/μl decrease, aHR: 1.25, 95% CI: 1.15–1.36). Improving access to early ART initiation and effective cervical cancer screening in women living with HIV should be key parts of global efforts to reduce cancer‐related health inequities.
The p53 tumor suppressor is inactivated in most cancers, thus suggesting that loss of p53 is a prerequisite for tumor growth. Therefore, its reintroduction through different means bears great clinical potential. After a brief introduction to current knowledge of p53 and its regulation by the ubiquitin-ligases MDM2/MDMX and post-translational modifications, we will discuss small molecules that are able to reactivate specific, frequently observed mutant forms of p53 and their applicability for clinical purposes. Many malignancies display amplification of MDM genes encoding negative regulators of p53 and therefore much effort to date has concentrated on the development of molecules that inhibit MDM2, the most advanced of which are being tested in clinical trials for sarcoma, glioblastoma, bladder cancer and lung adenocarcinoma. These will be discussed as will recent findings of MDMX inhibitors: these are of special importance as it has been shown that cancers that become resistant to MDM2 inhibitors often amplify MDM4. Finally, we will also touch on gene therapy and vaccination approaches; the former of which aims to replace mutated TP53 and the latter whose goal is to activate the body's immune system toward mutant p53 expressing cells. Besides the obvious importance of MDM2 and MDMX expression for regulation of p53, other regulatory factors should not be underestimated and are also described. Despite the beauty of the concept, the past years have shown that many obstacles have to be overcome to bring p53 reactivation to the clinic on a broad scale, and it is likely that in most cases it will be part of a combined therapeutic approach. However, improving current p53 targeted molecules and finding the best therapy partners will clearly impact the future of cancer therapy.
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