Combined anti-Galectin-1 and anti-EGFR siRNA-loaded chitosan-lipid nanocapsules decrease temozolomide resistance in glioblastoma: In vivo evaluation

Glioblastoma is the most frequent primary malignant brain tumor in adults. Despite treatments including surgery, radiotherapy and chemotherapy by oral Temozolomide (TMZ), the prognosis of patients with glioblastoma remains very poor. This is partly due to the resistance of malignant cells to therapy particularly TMZ. Overexpression of epidermal growth factor receptor (EGFR) and Galectin-1 by tumor cells significantly contributes to TMZ resistance. The purpose of this study was to evaluate in vivo, the effect of local administration by convection enhanced delivery (CED) of the anti-EGFR and anti-Galectin-1 siRNAs administered separately or in combination on (i) the survival of nude mice-bearing orthotopic U87MG glioblastoma cells and on (ii) the EGFR and Galectin-1 expression in excised U87MG tumor tissue. Both siRNAs were carried by chitosan lipid nanocapsules (LNCs). Survival of mice treated 14 days after tumor implantation by the combination of anti-EGFR and anti-Galectin-1 siRNAs and TMZ (40mg/kg) was significantly increased compared to animals treated by single anti-EGFR or anti-Galectin-1 siRNAs carried by chitosan-LNCs. This was confirmed by a decreased EGFR and Galectin-1 expression at the protein level in excised U87MG tumor tissue, 8 days post-transfection, visualized by immunofluorescence. This study demonstrates the potential of our strategy in glioblastoma therapy

Combined silencing expression of MGMT with EGFR or galectin-1 enhances the sensitivity of glioblastoma to temozolomide

Article de revue (Article scientifique dans une revue à comité de lecture)International audienceFor several years, the first line of treatment of glioblastoma (GB) patients is based on surgical resection followed by fractioned radiotherapy with concomitant and adjuvant chemotherapy with temozolomide (TMZ). The effectiveness of this treatment is very limited due to the development by tumor cells of mechanisms of resistance to TMZ such as over-expression of O6-methylguanine DNA methyltransferase (MGMT), epidermal growth factor receptor (EGFR) and galectin-1. In this study, we hypothesized that the targeting of MGMT, EGFR and galectin-1 (alone or in combination) by specifics siRNAs carried by chitosan-lipid nanocapsules (chitosan-LNCs) could enhance the sensitivity of U87MG cells to TMZ. We showed in vitro that (i) anti-MGMT and (ii) anti-EGFR or anti-galectin-1 siRNAs decreased significantly the expression of their corresponding proteins and increased the sensitivity of U87MG cells to TMZ. Additionally, the sensitivity of U87MG/MGMT- cells to TMZ was significantly increased when anti-EGFR and anti-galectin-1 siRNAs were combined with a percentage of living cells of 17.8±1.6% at 0.5 mg/mL concentration of TMZ. The combination of anti-MGMT siRNAs with either anti-EGFR or anti-galectin-1 siRNAs enhanced the sensitivity of U87MG/MGMT+ cells to TMZ in comparison to their separately use. No difference was observed between the association of the three siRNAs and other associations. At 0.5 mg/mL concentration of TMZ, the percentage of living cells decreased from 55.1±1.9% to 36.0±4.1% for anti-MGMT alone and the combination of anti-MGMT/anti-galectin-1/anti-EGFR siRNAs, respectively. These siRNA nanovectors represent a good alternative to enhance the effectiveness of the standard treatment of GB. This method could be implemented in future preclinical models for experimental cancer treatment of GB.</p

Rilpivirine in HIV-1-positive women initiating pregnancy: to switch or not to switch?

International audienceBackgroundSafety data about rilpivirine use during pregnancy remain scarce, and rilpivirine plasma concentrations are reduced during second/third trimesters, with a potential risk of viral breakthroughs. Thus, French guidelines recommend switching to rilpivirine-free combinations (RFCs) during pregnancy.ObjectivesTo describe the characteristics of women initiating pregnancy while on rilpivirine and to compare the outcomes for virologically suppressed subjects continuing rilpivirine until delivery versus switching to an RFC.MethodsIn the ANRS-EPF French Perinatal cohort, we included women on rilpivirine at conception in 2010–18. Pregnancy outcomes were compared between patients continuing versus interrupting rilpivirine. In women with documented viral suppression (<50 copies/mL) before 14 weeks of gestation (WG) while on rilpivirine, we compared the probability of viral rebound (≥50 copies/mL) during pregnancy between subjects continuing rilpivirine versus those switching to RFC.ResultsAmong 247 women included, 88.7% had viral suppression at the beginning of pregnancy. Overall, 184 women (74.5%) switched to an RFC (mostly PI/ritonavir-based regimens) at a median gestational age of 8.0 WG. Plasma HIV-1 RNA nearest delivery was <50 copies/mL in 95.6% of women. Among 69 women with documented viral suppression before 14 WG, the risk of viral rebound was higher when switching to RFCs than when continuing rilpivirine (20.0% versus 0.0%, P = 0.046). Delivery outcomes were similar between groups (overall birth defects, 3.8/100 live births; pregnancy losses, 2.0%; preterm deliveries, 10.6%). No HIV transmission occurred.ConclusionsIn virologically suppressed women initiating pregnancy, continuing rilpivirine was associated with better virological outcome than changing regimen. We did not observe a higher risk of adverse pregnancy outcomes