Early preclinical evidence provided the rationale for programmed cell death 1 (PD-1) and programmed death ligand 1 (PD-L1) blockade as a potential form of cancer immunotherapy given that activation of the PD-1/PD-L1 axis putatively served as a mechanism for tumor evasion of host tumor antigen-specific T-cell immunity. Early-phase studies investigating several humanized monoclonal IgG4 antibodies targeting PD-1 and PD-L1 in advanced solid tumors paved way for the development of the first PD-1 inhibitors, nivolumab and pembrolizumab, approved by the Food and Drug Administration (FDA) in 2014. The number of FDA-approved agents of this class is rapidly enlarging with indications for treatment spanning across a spectrum of malignancies. The purpose of this review is to highlight the clinical development of PD-1 and PD-L1 inhibitors in cancer therapy to date. In particular, we focus on detailing the registration trials that have led to FDA-approved indications of anti-PD-1 and anti-PD-L1 therapies in cancer. As the number of PD-1/PD-L1 inhibitors continues to grow, predictive biomarkers, mechanisms of resistance, hyperprogressors, treatment duration and treatment beyond progression, immune-related toxicities, and clinical trial design are key concepts in need of further consideration to optimize the anticancer potential of this class of immunotherapy.

SummaryEpigenetic reprogramming is a critical process of pathological gene induction during cardiac hypertrophy and remodeling. However, the underlying regulatory mechanism remains to be elucidated. Here we identified a heart-enriched long non-coding (lnc)RNA, named Cardiac Hypertrophy Associated Epigenetic Regulator (Chaer), necessary for the development of cardiac hypertrophy. Mechanistically, Chaer directly interacts with Polycomb Repressor Complex 2 (PRC2) catalytic subunit through a 66-mer motif, interferes with its targeting to genomic locus, and subsequently inhibits histone H3 lysine 27 methylation at hypertrophic genes. This interaction is transiently induced upon hormone or stress stimulation in an mTORC1 dependent manner, and is prerequisite for epigenetic reprogramming and induction of hypertrophic genes. Inhibition of Chaer in intact heart before, but not after, the onset of pressure overload significantly attenuates cardiac hypertrophy and dysfunction. Therefore, our study reveals that stress-induced pathological gene activation in heart requires a previously uncharacterized lncRNA-dependent epigenetic checkpoint.

BACKGROUND & AIMS-Endoplasmic reticulum (ER) stress responses (collectively known the unfolded protein response, UPR) have important roles in several human disorders, but their contribution to alcoholic pancreatitis is not known. We investigated the role of X box-binding protein 1 (XBP1), an UPR regulator, in prevention of alcohol-induced ER stress in the exocrine pancreas.

Nonalcoholic steatohepatitis (NASH) is a progressive disease that is often accompanied by metabolic syndrome and poses a high risk of severe liver damage. However, no effective pharmacological treatment is currently available for NASH. Here we report that CASP8 and FADD-like apoptosis regulator (CFLAR) is a key suppressor of steatohepatitis and its metabolic disorders. We provide mechanistic evidence that CFLAR directly targets the kinase MAP3K5 (also known as ASK1) and interrupts its N-terminus-mediated dimerization, thereby blocking signaling involving ASK1 and the kinase MAPK8 (also known as JNK1). Furthermore, we identified a small peptide segment in CFLAR that effectively attenuates the progression of steatohepatitis and metabolic disorders in both mice and monkeys by disrupting the N-terminus-mediated dimerization of ASK1 when the peptide is expressed from an injected adenovirus-associated virus 8-based vector. Taken together, these findings establish CFLAR as a key suppressor of steatohepatitis and indicate that the development of CFLAR-peptide-mimicking drugs and the screening of small-molecular inhibitors that specifically block ASK1 dimerization are new and feasible approaches for NASH treatment.