Combinatorial polymeric conjugated micelles with dual cytotoxic and antiangiogenic effects for the treatment of ovarian cancer

Emerging treatment paradigms like targeting the tumor microenvironment and/or dosing as part of a metronomic regimen are anticipated to produce better outcomes in ovarian cancer, but current drug delivery systems are lacking. We have designed and evaluated paclitaxel (PTX) and rapamycin (RAP) micellar systems that can be tailored for various dosing regimens and target tumor microenvironment. Individual and mixed PTX/RAP (MIX-M) micelles are prepared by conjugating drugs to a poly­(ethylene glycol)-<i>block</i>-poly­(β-benzyl l-aspartate) using a pH-sensitive linker. The micelles release the drug(s) at pH 5.5 indicating preferential release in the acidic endosomal/lysosomal environment. Micelles exhibit antiproliferative effects in ovarian cell cancer lines (SKOV-3 (human caucasian ovarian adenocarcinoma) and ES2 (human ovarian clear cell carcinoma)) and an endothelial cell line (HUVEC; human umbilical vein endothelial cells) with the MIX-M being synergistic. The micelles also inhibited endothelial migration and tube formation. In healthy mice, micelles at 60 mg/kg/drug demonstrated no acute toxicity over 21 days. ES2 xenograft model efficacy studies at 20 mg/kg/drug dosed every 4 days and evaluated at 21 days indicate that the individual micelles exhibit antiangiogenic effects, while the MIX-M exhibited both antiangiogenic and apoptotic induction that results in significant tumor volume reduction. On the basis of our results, MIX-M micelles can be utilized to achieve synergistic apoptotic and antiangiogenic effects when treated at frequent low doses

BCL11B regulates epithelial proliferation and asymmetric development of the mouse mandibular incisor.

Mouse incisors grow continuously throughout life with enamel deposition uniquely on the outer, or labial, side of the tooth. Asymmetric enamel deposition is due to the presence of enamel-secreting ameloblasts exclusively within the labial epithelium of the incisor. We have previously shown that mice lacking the transcription factor BCL11B/CTIP2 (BCL11B hereafter) exhibit severely disrupted ameloblast formation in the developing incisor. We now report that BCL11B is a key factor controlling epithelial proliferation and overall developmental asymmetry of the mouse incisor: BCL11B is necessary for proliferation of the labial epithelium and development of the epithelial stem cell niche, which gives rise to ameloblasts; conversely, BCL11B suppresses epithelial proliferation, and development of stem cells and ameloblasts on the inner, or lingual, side of the incisor. This bidirectional action of BCL11B in the incisor epithelia appears responsible for the asymmetry of ameloblast localization in developing incisor. Underlying these spatio-specific functions of BCL11B in incisor development is the regulation of a large gene network comprised of genes encoding several members of the FGF and TGFβ superfamilies, Sprouty proteins, and Sonic hedgehog. Our data integrate BCL11B into these pathways during incisor development and reveal the molecular mechanisms that underlie phenotypes of both Bcl11b(-/-) and Sprouty mutant mice

Expression Analysis of the Stem Cell Marker <i>Pw1/Peg3</i> Reveals a CD34 Negative Progenitor Population in the Hair Follicle

International audiencePw1/Peg3 is a parentally imprinted gene expressed in adult stem cells in every tissue thus far examined including the stem cells of the hair follicle. Using a Pw1/Peg3 reporter mouse, we carried out a detailed dissection of the stem cells in the bulge, which is a major stem cell compartment of the hair follicle in mammalian skin. We observed that PW1/Peg3 expression initiates upon placode formation during fetal development, coincident with the establishment of the bulge stem cells. In the adult, we observed that PW1/Peg3 expression is found in both CD34+ and CD34- populations of bulge stem cells. We demonstrate that both populations can give rise to new hair follicles, reconstitute their niche, and self-renew. These results demonstrate that PW1/Peg3 is a reliable marker of the full population of follicle stem cells and reveal a novel CD34- bulge stem-cell population. Stem Cells 2017;35:1015–102

Epithelial invagination defect in <i>Bcl11b^−/−</i> developing incisors between initiation and early bud stage.

<p>(A-D) H&E staining in sections of wild-type and <i>Bcl11b^−/−</i> mice at indicated developmental stages. The epithelium is outlined in black. (E-H) BrdU immunostaining (green) in sections of wild-type and <i>Bcl11b^−/−</i> mice. All sections were counterstained with DAPI (blue). The epithelium is outlined in white. (I-J) BrdU index of wild-type and <i>Bcl11b^−/−</i> dental epithelium; *** denotes statistical significance at p ≤ 0.001, n = 3. (K-N) RNA ISH using a <i>Bmp4</i> probe in sections of wild-type and <i>Bcl11b^−/−</i> mice at indicated developmental stages. The epithelium is outlined by red dots. Red arrows denote epithelial staining. Scale bar, 100 µm.</p

Altered ameloblast development in <i>Bcl11b^−/−</i> incisors.

<p>RNA ISH using the indicated probes in sections of wild-type and <i>Bcl11b^−/−</i> mice at indicated developmental stages. The epithelium is outlined by red dots. Red arrows and arrowheads denote labial and lingual epithelial staining, respectively. Scale bars: (A-B, E-F) 500 µm; other panels, 200 µm.</p

BCL11B expression during incisor development.

<p>BCL11B immunostaining in sections of wild-type mice at indicated developmental stages. The epithelium is outlined by white dots. Scale bars: (A-B) 100 µm; (C) 200 µm; (D-E) 500 µm. a, ameloblasts; an, anterior; cl, cervical loop; de, dental epithelium; df, dental follicle; dm, dental mesenchyme; iee, inner enamel epithelium; lab, labial; lin, lingual; oee, outer enamel epithelium; pm, papillary mesenchyme; po, posterior; sr, stellate reticulum; vl, vestibular lamina.</p

Altered expression of TGFβ genes and <i>Fst</i> in <i>Bcl11b^−/−</i> incisor.

<p>RNA ISH using the indicated probes in sections of wild-type and <i>Bcl11b^−/−</i> incisors at indicated developmental stages. The epithelium is outlined by red dots. Black and red arrows denote labial mesenchymal and epithelial staining, respectively, and black and red arrowheads indicate lingual mesenchymal and epithelial staining, respectively. Black and red asterisks denote staining in the posterior part of the dental follicle and epithelial tip of the incisor, respectively. Scale bars: (A-B, E-F, I-J) 500 µm; other panels, 200 µm.</p