Microneedle-Assisted Topical Delivery of Photodynamically Active Mesoporous Formulation for Combination Therapy of Deep-Seated Melanoma.

ACS Nano. 2018 Nov 16;:

Authors: Tham HP, Xu K, Lim WQ, Chen H, Zheng M, Thng TGS, Venkatraman SS, Xu C, Zhao Y

Abstract
Topical treatment using photodynamic therapy (PDT) for many types of skin cancers has largely been limited by the inability of existing photosensitizers to penetrate into the deep skin tissue. To overcome these problems, we developed a mesoporous nanovehicle with dual loading of photosensitizers and clinically relevant drugs for combination therapy, while utilizing microneedle technology to facilitate their penetration into deep skin tissue. Sub-50 nm photodynamically active mesoporous organosilica nanoparticles were synthesized with photosensitizers covalently bonded to the silica matrix, which dramatically increased the quantum yield and photostability of these photosensitizers. The mesopores of the nanoparticles were further loaded with small-molecule inhibitors, i. e., dabrafenib and trametinib, that target the hyperactive mitogen-activated protein kinase (MAPK) pathway for melanoma treatment. As-prepared empty nanovehicle was cytocompatible with normal skin cells in the dark, while NIR-irradiated drug-loaded nanovehicle showed a synergistic killing effect on skin cancer cells mainly through reactive oxygen species and caspase-activated apoptosis. The nanovehicle could significantly inhibit the proliferation of tumor cells in a 3D spheroid model in vitro. Porcine skin fluorescence imaging demonstrated that microneedles could facilitate the penetration of nanovehicle across the epidermis layer of skin to reach deep-seated melanoma sites. Tumor regression studies in a xenografted melanoma mouse model confirmed superior therapeutic efficacy of the nanovehicle through combinational PDT and targeted therapy.

PMID: 30444343 [PubMed - as supplied by publisher]

Cytoplasmic Pin1 expression is increased in human cutaneous melanoma and predicts poor prognosis.

Sci Rep. 2018 Nov 15;8(1):16867

Authors: Chen X, Liu X, Deng B, Martinka M, Zhou Y, Lan X, Cheng Y

Abstract
The prolyl isomerase Pin1 is widely over-expressed or over-activated in cancers and promotes tumorigenesis. The authors investigated the expression level of Pin1 and analyzed the prognostic value of Pin1 expression using a large-scale melanoma tissue microarray study. Two independent sets of tissue microarrays were employed, including 114 melanoma cases in the discovery set and 424 in the validation set (538 cases in total), 32 normal nevi and 86 dysplastic nevi 118 cases of nevi. The subcellular Pin1 expression in different stages of melanocytic lesions and its prognostic significance were studied. High expression (IRS 0-8) of cytoplasmic Pin1 was observed in 3.13%, 8.33%, 16.49% and 22.76% of the biopsies in normal nevi, dysplastic nevi, primary melanoma and metastatic melanoma, respectively. Significant differences for cytoplasmic Pin1 staining were observed between normal nevi and metastatic melanoma (P = 0.011, χ2 test), between dysplastic nevi and primary melanoma (P = 0.046, χ2 test) and between dysplastic nevi and metastatic melanoma (P = 0.016, χ2 test). Kaplan-Meier survival analysis showed that increased cytoplasmic Pin1 expression was associated with a worse 5-year melanoma-specific survival of melanoma (P < 0.001) and metastatic melanoma patients (P = 0.004). Multivariate Cox regression analysis showed that cytoplasmic Pin1 expression is an independent prognostic factor in melanoma. Our data indicate that cytoplasmic Pin1 plays an important role in melanoma pathogenesis and progression, and serve as a potential prognostic marker for melanoma.

PMID: 30442923 [PubMed - in process]