Structural basis of HLX10 PD-1 receptor recognition, a promising anti-PD-1 antibody clinical candidate for cancer immunotherapy.

Cancer immunotherapies, such as checkpoint blockade of programmed cell death protein-1 (PD-1), represents a breakthrough in cancer treatment, resulting in unprecedented results in terms of overall and progression-free survival. Discovery and development of novel anti PD-1 inhibitors remains a field of intense investigation, where novel monoclonal antibodies (mAbs) and novel antibody formats (e.g., novel isotype, bispecific mAb and low-molecular-weight compounds) are major source of future therapeutic candidates. HLX10, a fully humanized IgG4 monoclonal antibody against PD-1 receptor, increased functional activities of human T-cells and showed in vitro, and anti-tumor activity in several tumor models. The combined inhibition of PD-1/PDL-1 and angiogenesis pathways using anti-VEGF antibody may enhance a sustained suppression of cancer-related angiogenesis and tumor elimination. To elucidate HLX10's mode of action, we solved the structure of HLX10 in complex with PD-1 receptor. Detailed epitope analysis showed that HLX10 has a unique mode of recognition compared to the clinically approved PD1 antibodies Pembrolizumab and Nivolumab. Notably, HLX10's epitope was closer to Pembrolizumab's epitope than Nivolumab's epitope. However, HLX10 and Pembrolizumab showed an opposite heavy chain (HC) and light chain (LC) usage, which recognizes several overlapping amino acid residues on PD-1. We compared HLX10 to Nivolumab and Pembrolizumab and it showed similar or better bioactivity in vitro and in vivo, providing a rationale for clinical evaluation in cancer immunotherapy.

Magnetic Interaction of Multifunctional Core-Shell Nanoparticles for Highly Effective Theranostics.

The controlled size and surface treatment of magnetic nanoparticles (NPs) make one-stage combination feasible for enhanced magnetic resonance imaging (MRI) contrast and effective hyperthermia. However, superparamagnetic behavior, essential for avoiding the aggregation of magnetic NPs, substantially limits their performance. Here, a superparamagnetic core-shell structure is developed, which promotes the formation of vortex-like intraparticle magnetization structures in the remanent state, leading to reduced dipolar interactions between two neighboring NPs, while during an MRI scan, the presence of a DC magnetic field induces the formation of NP chains, introducing increased local inhomogeneous dipole fields that enhance relaxivity. The core-shell NPs also reveal an augmented anisotropy, due to exchange coupling to the high anisotropy core, which enhances the specific absorption rate. This in vivo tumor study reveals that the tumor cells can be clearly diagnosed during an MRI scan and the tumor size is substantially reduced through hyperthermia therapy by using the same FePt@iron oxide nanoparticles, realizing the concept of theranostics.

let-7 Modulates Chromatin Configuration and Target Gene Repression through Regulation of the ARID3B Complex.

Let-7 is crucial for both stem cell differentiation and tumor suppression. Here, we demonstrate a chromatin-dependent mechanism of let-7 in regulating target gene expression in cancer cells. Let-7 directly represses the expression of AT-rich interacting domain 3B (ARID3B), ARID3A, and importin-9. In the absence of let-7, importin-9 facilitates the nuclear import of ARID3A, which then forms a complex with ARID3B. The nuclear ARID3B complex recruits histone demethylase 4C to reduce histone 3 lysine 9 trimethylation and promotes the transcription of stemness factors. Functionally, expression of ARID3B is critical for the tumor initiation in let-7-depleted cancer cells. An inverse association between let-7 and ARID3A/ARID3B and prognostic significance is demonstrated in head and neck cancer patients. These results highlight a chromatin-dependent mechanism where let-7 regulates cancer stemness through ARID3B.

Emblica officinalis Gaertn. attentuates N-nitrosodiethylamine-induced apoptosis, autophagy, and inflammation in rat livers.

Inflammation and oxidative stress contribute to liver injury. Amla (Emblica officinalis Gaertn.) is rich in vitamin C, gallic acid, flavonoids, and tannins, which may protect against hepatoxicity-induced liver injury. We elucidated the effects of supplementary Amla (100 mg/kg of body weight) on N-nitrosodiethylamine-induced injury by evaluating reactive oxygen species (ROS) responses in the liver and bile, the degree of accumulated leukocytes and Kupffer cell infiltration, 3-nitrotyrosine and 4-hydroxynonenal stains, apoptosis and autophagy, plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamyl transpeptidase (γ-GT) levels, and antioxidant/oxidant enzymes in rats. Amla was more potent than vitamin C in scavenging O2⁻·, hydrogen peroxide, and nitric oxide. N-Nitrosodiethylamine increased ROS production in liver and bile, hepatic Kupffer cell and leukocyte infiltration, 3-nitrotyrosine and 4-hydroxynonenal accumulations, apoptosis and autophagy, and plasma ALT, AST, and γ-GT levels in the rats, decreased hepatic manganese superoxide dismutase (MnSOD) and catalase protein expressions, and enhanced inducible nitric oxide synthase (iNOS) and cytochrome P450 2E1 (CYP2E1) protein expressions. Amla significantly preserved MnSOD and catalase expressions and decreased iNOS and CYP2E1 protein expressions in N-nitrosodiethylamine-treated livers. Amla decreased N-nitrosodiethylamine-enhanced hepatic apoptosis and autophagy appearances via down-regulation of the Bax/Bcl-2 ratio and Beclin-1 expression. Thus Amla supplementation counteracts N-nitrosodiethylamine-induced liver injury via its antioxidant, anti-inflammation, anti-apoptosis, and anti-autophagy properties.