Clinical relevance of KRAS mutation detection in metastatic colorectal cancer treated by Cetuximab plus chemotherapy

The predictive value of KRAS mutation in metastatic colorectal cancer (MCRC) patients treated with cetuximab plus chemotherapy has recently been suggested. In our study, 59 patients with a chemotherapy-refractory MCRC treated with cetuximab plus chemotherapy were included and clinical response was evaluated according to response evaluation criteria in solid tumours (RECIST). Tumours were screened for KRAS mutations using first direct sequencing, then two sensitive methods based on SNaPshot and PCR-ligase chain reaction (LCR) assays. Clinical response was evaluated according to gene mutations using the Fisher exact test. Times to progression (TTP) were calculated using the Kaplan–Meier method and compared with log-rank test. A KRAS mutation was detected in 22 out of 59 tumours and, in six cases, was missed by sequencing analysis but detected using the SNaPshot and PCR-LCR assays. Remarkably, no KRAS mutation was found in the 12 patients with clinical response. KRAS mutation was associated with disease progression (P=0.0005) and TTP was significantly decreased in mutated KRAS patients (3 vs 5.5 months, P=0.015). Our study confirms that KRAS mutation is highly predictive of a non-response to cetuximab plus chemotherapy in MCRC and highlights the need to use sensitive molecular methods, such as SNaPshot or PCR-LCR assays, to ensure an efficient mutation detection

Recent HIV-1 Infection Contributes to the Viral Diffusion over the French Territory with a Recent Increasing Frequency

To analyse the contribution of primary human immunodeficiency virus type 1 (HIV-1) infection (PHI) to the French viral epidemic. sequences included 987 PHI from the French ANRS PRIMO cohort between 1999 and 2010 and were analysed using a population-based phylogenetic approach. Clinical features, risk factors, sexual behaviour and drug resistance for clustered and nonclustered transmission events were ascertained.Viruses from 125 (12.7%) of PHI cosegregated into 56 transmission chains, with increasing frequency during the last years (10.2% before 2006 versus 15.2% of clusters in 2006–2010, p = 0.02). The mean number of patients per cluster was 2.44. Compared to unique PHI, clusters involved more often men, infected through homosexual intercourse, of young age, with a high number of casual sexual partnerships and frequent previous HIV serological tests. Resistant strains were found in 16.0% and 11.1% of clusters and unique PHI, respectively (p = 0.11). Overall, 34% (n = 19) clusters included patients followed in French regions far apart, involving 13 clusters with at least one Parisian patient.PHIs are a significant source of onward transmission, especially in the MSM population. Recently infected people contribute to the spread of the viral epidemic throughout the French territory. Survey of transmitted drug resistance and behavioural characteristics of patients involved into clustered PHI may help to guide prevention and treatment interventions

Human neural crest cells display molecular and phenotypic hallmarks of stem cells

The fields of both developmental and stem cell biology explore how functionally distinct cell types arise from a self-renewing founder population. Multipotent, proliferative human neural crest cells (hNCC) develop toward the end of the first month of pregnancy. It is assumed that most differentiate after migrating throughout the organism, although in animal models neural crest stem cells reportedly persist in postnatal tissues. Molecular pathways leading over time from an invasive mesenchyme to differentiated progeny such as the dorsal root ganglion, the maxillary bone or the adrenal medulla are altered in many congenital diseases. To identify additional components of such pathways, we derived and maintained self-renewing hNCC lines from pharyngulas. We show that, unlike their animal counterparts, hNCC are able to self-renew ex vivo under feeder-free conditions. While cross species comparisons showed extensive overlap between human, mouse and avian NCC transcriptomes, some molecular cascades are only active in the human cells, correlating with phenotypic differences. Furthermore, we found that the global hNCC molecular profile is highly similar to that of pluripotent embryonic stem cells when compared with other stem cell populations or hNCC derivatives. The pluripotency markers NANOG, POU5F1 and SOX2 are also expressed by hNCC, and a small subset of transcripts can unambiguously identify hNCC among other cell types. The hNCC molecular profile is thus both unique and globally characteristic of uncommitted stem cells

Les associations fixes améliorent-elles l'observance ? (une méta-analyse)

LYON1-BU Santé (693882101) / SudocSudocFranceF

Les études post-AMM demandées par les autorités de santé (exemple de l'étude d'épidémiologie clinique chez les patients traités par Lantus)

Le diabète est une pathologie dont les nombreuses complications et l augmentation de l incidence font une priorité de Santé Publique. Afin d aider les patients à optimiser le contrôle de leur maladie, de nouveaux schémas thérapeutiques sont développés grâce à des médicaments innovants. L insuline Lantus® a fait partie intégrante de ces innovations en 2003, de part sa pharmacocinétique inédite. Les études observationnelles post-AMM des nouveaux traitements permettent de connaître les modalités de leur utilisation dans la pratique quotidienne. Ce mémoire expose le rationnel des études observationnelles. Les différents types de diabètes sont ensuite détaillés, leurs physiopathologies, leurs traitements et leurs complications afin d interpréter l étude d épidémiologie clinique chez les patients traités par Lantus®. La méthodologie, la conduite et les résultats de cette étude feront l objet de la dernière partie de cet ouvrage.DIJON-BU Médecine Pharmacie (212312103) / SudocSudocFranceF

Combination of 3' and 5' IgH regulatory elements mimics the B-specific endogenous expression pattern of IgH genes from pro-B cells to mature B cells in a transgenic mouse model.

To ensure the B cell differentiation stage specificity of the intronic Emu element and of the locus control region (LCR) that lies downstream of the IgH chain locus, we generated transgenic mice harboring a V(H) promoter-GFP reporter gene linked to the 3'LCR region and the Emu element. By flow cytometry, GFP(+) lymphocytes were observed amongst pro-B cells (B220(+)CD43(+)CD117(+)) and at all stages of differentiation up to mature B cells (B220(+)IgM(+)IgD(+)). Expression was strictly confined to cells committed to the B lymphocyte lineage as judged by the lack of GFP(+)Thy1,2(+) cells (T lymphocytes) and GFP(+)B220(-)CD117(+)CD43(+) cells (uncommitted lymphohematopoietic progenitors). Therefore, the Emu-GFP-3'LCR transgene is not expressed by hematopoietic stem cells, begins its expression in pro-B cells and is specifically active at all stages of B cell maturation. The combination of 3' and 5' IgH regulatory elements thus appears as a potentially useful cassette in transgenes that require a stringent and early B lineage-specific expression

FOLFIRINOX relative dose intensity and disease control in advanced pancreatic adenocarcinoma

International audienceBackground: Most patients with advanced pancreatic adenocarcinoma (PA) treated with FOLFIRINOX experience adverse events requiring dose reduction. We aimed to assess the association between relative dose intensity (RDI) and disease control in a European setting. Methods: We retrospectively included patients with advanced PA treated with three or more cycles of FOLFIRINOX between 2011 and 2018 in six French centers. We computed the cumulative single-agent RDI (csRDI) before the first reassessment for each FOLFIRINOX agent (oxaliplatin, irinotecan, 5FU bolus, and 5FU intravenous infusion) and the cumulative multi-drug RDI (cmRDI) of their combination. The association between RDI and disease control or objective response at first reassessment was evaluated using multivariable logistic regression models controlling for performance status, liver metastases, and center. Results: We included 243 patients. Median csRDIs were 81%, 79%, 75%, and 85% for oxaliplatin, irinotecan, 5FU bolus, and 5FU intravenous infusion, respectively. Median cmRDI was 80%. None of the RDIs was significantly associated with disease control or objective response. Including RDI in a clinical model did not improve its ability to predict disease control; the area under the curve was 0.79 (95% CI: 0.73-0.85) with RDI versus 0.78 (95% CI: 0.72-0.85) without. Similar results were observed for the objective response. Conclusion: Pragmatic dose adjustments of FOLFIRINOX should be made by oncologists without considering a loss of effect