Summary In selective autophagy, receptors are central for cargo selection and delivery. However, it remains yet unclear whether and how multiple autophagy receptors might form complex and function concertedly to control autophagy. Optineurin (OPTN), implicated genetically in glaucoma and amyotrophic lateral sclerosis, was a recently identified autophagy receptor. Here we report that tumor suppressor HACE1, a ubiquitin ligase, ubiquitylates OPTN and promotes its interaction with p62/SQSTM1 to form the autophagy receptor complex, thus accelerating autophagic flux. Interestingly, the K48-linked polyubiquitin chains that HACE1 conjugates onto OPTN might predominantly target OPTN for autophagic degradation. By demonstrating that the HACE1-OPTN axis synergistically suppresses growth and tumorigenicity of lung cancer cells, our findings may open an avenue for developing autophagy-targeted therapeutic intervention into cancer.

BackgroundPD-L1 is an immune inhibitory receptor ligand that leads to T cell dysfunction and apoptosis by binding to its receptor PD-1, which works in braking inflammatory response and conspiring tumor immune evasion. However, in gliomas, the cause of PD-L1 expression in the tumor microenvironment is not yet clear. Besides, auxiliary biomarkers are urgently needed for screening possible responsive glioma patients for anti-PD-1/PD-L1 therapies.MethodsThe distribution of tumor-infiltrating T cells and PD-L1 expression was analyzed via immunofluorescence in orthotopic murine glioma model. The expression of PD-L1 in immune cell populations was detected by flow cytometry. Data excavated from TCGA LGG/GBM datasets and the Ivy Glioblastoma Atlas Project was used for in silico analysis of the correlation among genes and survival.ResultsThe distribution of tumor-infiltrating T cells and PD-L1 expression, which parallels in murine orthotopic glioma model and human glioma microdissections, was interrelated. The IFN-γ level was positively correlated with PD-L1 expression in murine glioma. Further, IFN-γ induces PD-L1 expression on primary cultured microglia, bone marrow-derived macrophages, and GL261 glioma cells in vitro. Seven IFN-γ-induced genes, namely GBP5, ICAM1, CAMK2D, IRF1, SOCS3, CD44, and CCL2, were selected to calculate as substitute indicator for IFN-γ level. By combining the relative expression of the listed IFN-γ-induced genes, IFN-γ score was positively correlated with PD-L1 expression in different anatomic structures of human glioma and in glioma of different malignancies.ConclusionOur study identified the distribution of tumor-infiltrating T cells and PD-L1 expression in murine glioma model and human glioma samples. And we found that IFN-γ is an important cause of PD-L1 expression in the glioma microenvironment. Further, we proposed IFN-γ score aggregated from the expressions of the listed IFN-γ-induced genes as a complementary prognostic indicator for anti-PD-1/PD-L1 therapy.Electronic supplementary materialThe online version of this article (10.1186/s12974-018-1330-2) contains supplementary material, which is available to authorized users.

Alterations in cellular ubiquitin (Ub) homeostasis, known as Ub stress, feature and affect cellular responses in multiple conditions, yet the underlying mechanisms are incompletely understood. Here we report that autophagy receptor p62/sequestosome-1 interacts with E2 Ub conjugating enzymes, UBE2D2 and UBE2D3. Endogenous p62 undergoes E2-dependent ubiquitylation during upregulation of Ub homeostasis, a condition termed as Ub stress, that is intrinsic to Ub overexpression, heat shock or prolonged proteasomal inhibition by bortezomib, a chemotherapeutic drug. Ubiquitylation of p62 disrupts dimerization of the UBA domain of p62, liberating its ability to recognize polyubiquitylated cargoes for selective autophagy. We further demonstrate that this mechanism might be critical for autophagy activation upon Ub stress conditions. Delineation of the mechanism and regulatory roles of p62 in sensing Ub stress and controlling selective autophagy could help to understand and modulate cellular responses to a variety of endogenous and environmental challenges, potentially opening a new avenue for the development of therapeutic strategies against autophagy-related maladies.

The clinical outcomes and therapeutic strategies for infiltrating ductal carcinoma (IDC) and infiltrating lobular carcinoma (ILC) are not uniform. The primary objectives of this study were to identify the differences in the clinical characteristics and prognoses between ILC and IDC, and identify the high-risk population based on the hormone receptor status and metastasis sites. The Surveillance, Epidemiology, and End Results Program database was searched and patients diagnosed with ILC or IDC from 1990 to 2013 were identified. In total,796,335 patients were analyzed, including 85,048 withILC (10.7%) and 711,287 withIDC (89.3%). The ILC group was correlatedwith older age, larger tumor size, later stage, lower grade, metastasis disease(M1) disease, and greater counts ofpositive lymph nodesandestrogen-receptor-positive (ER)/progesterone receptor-positive (PR) positive nodes. The overall survival showed an early advantage for ILC but a worse outcome after 5 years. Regarding the disease-specific survival, the IDC cohort had advantages over the ILC group, both during the early years and long-term. In hormone status and metastasis site subgroup analyses, the ER+/PR+ subgroup had the best survival, while the ER+/PR- subgroup had the worst outcome, especially the ILC cohort. ILC and IDC had different metastasis patterns. The proportion of bone metastasis was higher in the ILC group (91.52%) than that in the IDC (76.04%), and the ILC group was more likely to have multiple metastasis sites. Survival analyses showed patients with ILC had a higher risk of liver metastasis (disease-specific survival[DSS]; P = 0.046), but had a better overall survival than the bone metastasis group (P<0.0001). We concluded that the long-term prognosis for ILC was poorer than that for IDC, and the ER+/PR- subgroup had the worst outcome. Therefore, the metastasis pattern and prognosis must be seriously evaluated, and a combination of endocrine therapy and chemotherapy should be considered.

Periostin neutralizing Ab. The hybridoma cell lines secreting mouse mAb against mouse periostin were generated by Abmart Co., according to the standard hybridoma technique (72). The mouse mAbs were purified by Protein A affinity chromatograph. mAb purity was confirmed by HPLC. The concentrations of the obtained mAbs were measured by Mouse IgG ELISA Quantitation kit (Bethyl Laboratories), following the manufacturer's instructions. The kinetic parameters of the mAbs were determined using a Biacore T100 instrument (Biacore AB). Purified Ab was diluted in saline and injected at a dose of 5 mg/kg into db/db mice for 2 weeks.Statistics. All values are shown as mean ± SEM. Statistical differences were determined by 2-way ANOVA with Bonferroni-adjusted post-test or by 2-tailed Student's t test. A P value less than 0.05 was considered significant.

Non-alcoholic fatty liver disease (NAFLD) is characterized by the aberrant accumulation of triglycerides in hepatocytes in the absence of significant alcohol consumption, viral infection or other specific causes of liver disease. NAFLD has become a burgeoning health problem both worldwide and in China, but its pathogenesis remains poorly understood. Farnesoid X receptor (FXR), a member of the nuclear receptor (NR) superfamily, has been demonstrated to be the primary sensor for endogenous bile acids, and play a crucial role in hepatic triglyceride homeostasis. Deciphering the synergistic contributions of FXR to triglyceride metabolism is critical for discovering therapeutic agents in the treatment of NAFLD and hypertriglyceridemia.

Aim: HMGB1 (high-mobility group box-1) is a nuclear protein containing a consensus RB (retinoblastoma)-binding LXCXE motif. In this study, we studied the potential association of HMGB1 and RB and the in vitro and in vivo activities of HMGB1 in human breast cancer cells. Methods: The protein-protein interaction was determined by immunoprecipitation-Western blotting and glutathione-S-transferase capture assays; cell growth and radiosensitivity were examined by cell counts, MTT assay, and clonogenic assay; cell cycle progression and apoptosis were evaluated using flow cytometry; and the antitumor activity of HMGB1 was examined with tumor xenografts in nude mice. Results: HMGB1 was associated with RB via a LXCXE motif-dependent mechanism. HMGB1 enhanced the ability of RB for E2F and cyclin A transcription repression. The increased expression of HMGB1 conferred an altered phenotypes characterized by the suppression of cell growth; G 1 arrest and apoptosis was induced in MCF-7 cells containing the wildtype retinoblastoma (Rb) gene, but showed no activities in BT-549 cells containing the Rb gene deletion. The HMGB1-induced apoptosis accompanied by caspase 3 activation and PARP (poly(ADP-ribose)polymerase) cleavage. HMGB1 elevated the radiosensitivity of breast cancer cells in both the MCF-7 and BT-549 cell lines. The enhanced expression of HMGB1 caused a suppression of growth of MCF-7 tumor xenografts in nude mice, while LXCXE-defective HMGB1 completely lost antitumor growth activity. Conclusion: HMGB1 functions as a tumor suppressor and radiosensitizer in breast cancer. A HMGB1-RB interaction is critical for the HMGB1-mediated transcriptional repression, cell growth inhibition, G 1 cell cycle arrest, apoptosis induction, and tumor growth suppression, but is not required for radiosensitization. Therefore, it may be possible to design new therapies for the treatment of breast cancer that exert their effects by modulating the HMGB1 and RB regulatory pathway and HMGB1-related gene therapy.

The aim of this study was to determine the clinical features, treatment factors, and prognosis of patients with multiple primary malignant tumors (MPMTs). In total, 161 patients with MPMTs at our hospital (The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China) were analyzed in this study. We found that among 161 patients with MPMTs, 78 (48.4%) patients had synchronous tumors and 83 (51.6%) patients had metachronous tumors. Most clinical and pathological features were similar in both groups. Most patients with MPMTs were men and older patients (>50 years old), and adenocarcinoma was the most frequent pathology type. The most frequent location of all MPMTs was the digestive system. The leading tumor association was between digestive–digestive tumors, also. However, patients with synchronous tumors and MPMTs of the digestive system showed a shorter survival time. In the metachronous cancer group, the median interval time was 60 months, and a short interval time (≤60 months) was associated with a shorter survival time. In addition, survival time was increased in the younger age group (≤50 years old) and in patients who accepted surgery-based comprehensive therapy. However, only interval time (≤60 months) was an independent prognostic factor associated with survival for the metachronous cancer group. Therefore, careful surveillance and follow-up are especially important in these patients.