Supramolecular Prodrug Nanovectors for Active Tumor Targeting and Combination Immunotherapy of Colorectal Cancer.

Immunotherapy aiming to harness the exquisite power of the immune system has emerged as a crucial part of clinical cancer management. However, only a subset of cancer patients responds to current immunotherapy because of low immunogenicity of the tumor cells and immunosuppressive tumor microenvironment. Herein, host-guest prodrug nanovectors are reported for active tumor targeting and combating immune tolerance in tumors. The prodrug nanovectors are designed by integrating hyaluronic acid (HA) and reduction-labile heterodimer of Pheophorbide A (PPa) and NLG919 into the supramolecular nanocomplexes, where PPa and NLG919 act as a photosensitizer and potent inhibitor of indoleamine 2,3-dioxygenase 1 (IDO-1), respectively. Meanwhile, HA is employed to achieve active tumor targeting by recognizing CD44 overexpressed on the surface of tumor cell membranes. Near infrared (NIR) laser irradiation triggers the release of reactive oxygen species to provoke antitumor immunogenicity and intratumoral infiltration of cytotoxic T lymphocytes (CTLs). Meanwhile, the immunosuppressive tumor microenvironment (ITM) is reversed by NLG919-mediated IDO-1 inhibition. Combination of photodynamic immunotherapy and IDO-1 blockade efficiently eradicates CT26 colorectal tumors in the immunocompetent mice. The host-guest nanoplatform capable of eliciting effective antitumor immunity by inactivating inhibitory immune response can be applied to other immune modulators for improved cancer immunotherapy.

Design, Synthesis, and Biological Evaluation of Imidazo[1,2-a]pyridine Derivatives as Novel PI3K/mTOR Dual Inhibitors.

PI3K-Akt-mTOR signaling pathway has been validated as an effective targeting pathway for cancer therapy. However, no PI3K/mTOR dual inhibitor has been approved by the FDA yet. Therefore, it is still essential to discover a candidate with good efficacy and low toxicity. In our design, a series of imidazo[1,2-a]pyridine derivatives had been synthesized and subjected to activity assessment in vitro and in vivo. 15a was proved to be a potent PI3K/mTOR dual inhibitor with excellent kinase selectivity, modest plasma clearance, and acceptable oral bioavailability. Besides, 15a displayed significant inhibition of tumor growth in HCT116 and HT-29 xenografts without obvious effect on body weight.

Silencing of LncRNA BDNF-AS attenuates Aß25-35-induced neurotoxicity in PC12 cells by suppressing cell apoptosis and oxidative stress.

OBJECTIVE: To explore the effects of long non-coding RNA (lncRNA) brain-derived neurotrophic factor anti-sense (BDNF-AS) on the Aß25-35-induced neurotoxicity in PC12 cells. METHODS: PC12 cells were induced by Aß25-35 to construct cell injury models of Alzheimer's disease (AD), and then transfected with siRNA-BDNF-AS. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to detect the expressions of BDNF-AS and BDNF. Besides, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Hoechst33342 staining were utilized to analyze the cell viability and apoptosis, respectively, Western blotting to evaluate the protein expressions, immunofluorescence to assess the Cytochrome C (Cyt C) release, and Rhodamine 123 (Rh123) to measure the mitochondrial membrane potential (MMP).The evaluation of oxidative stress was conducted via the determination of the levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT). RESULTS: Aß25-35 apparently increased BDNF-AS but decreased BDNF in PC12 cells, which also reduced viability and induced apoptosis of PC12 cells. Silencing of BDNF-AS could significantly up-regulate BDNF in Aß25-35-induced PC12 cells, with the elevated cell viability. Moreover, silencing BDNF-AS inhibited the apoptosis of Aß25-35-induced PC12 cells, suppressed the release of Cyt C, reduced the expression of cleaved caspase-3 and Bax, and lowered the mean fluorescence intensity (MFI) of Rh123, but it elevated the expression of Bcl-2. Besides, silencing BDNF-AS also reduced ROS intensity and MDA content, but enhanced the activities of SOD and CAT. CONCLUSION: Silencing BDNF-AS exerts protective functions to increase the viability, inhibit the apoptosis and oxidative stress of Aß25-35-induced PC12 cells by negative regulation of BDNF. ABBREVIATIONS: Aß25-35: amyloid beta peptide 25-35; AD: Alzheimer's disease; LncRNA BDNF-AS: long non-coding RNA brain-derived neurotrophic factor anti-sense; OS: Oxidative stress.