The Circadian Clock Component RORA Increases Immunosurveillance in Melanoma by Inhibiting PD-L1 Expression.

Circadian clock perturbation frequently occurs in cancer and facilitates tumor progression by regulating malignant growth and shaping the immune microenvironment. Emerging evidence has indicated that clock genes are disrupted in melanoma and linked to immune escape. Here, we found that the expression of retinoic acid receptor-related orphan receptor-α (RORA) is downregulated in melanoma patients and that patients with higher RORA expression have a better prognosis after immunotherapy. Additionally, RORA was significantly positively correlated with T-cell infiltration and recruitment. Overexpression or activation of RORA stimulated cytotoxic T-cell-mediated antitumor responses. RORA bound to the CD274 promoter and formed an inhibitory complex with HDAC3 to suppress PD-L1 expression. In contrast, the DEAD-box helicase family member DDX3X competed with HDAC3 for binding to RORA, and DDX3X overexpression promoted RORA release from the suppressive complex and thereby increased PD-L1 expression to generate an inhibitory immune environment. The combination of a RORA agonist with an anti-CTLA4 antibody synergistically increased T-cell antitumor immunity in vivo. A score based on the combined expression of HDAC3, DDX3X and RORA correlated with immunotherapy response in melanoma patients. Together, this study elucidates a mechanism of clock component-regulated antitumor immunity, which will help inform the use of immunotherapy and lead to improved outcomes for melanoma patients receiving combined therapeutic treatments.

Purinergic receptor P2X7 contributes to abdominal aortic aneurysm development via modulating macrophage pyroptosis and inflammation.

The purinergic receptor P2X7 has been established as an important mediator of inflammation and participates in a variety of cardiovascular diseases including atherosclerosis, however, its role in abdominal aortic aneurysms (AAA) remains unclear. In this study, we demonstrate that P2X7 plays essential roles in AAA development via modulating macrophage pyroptosis and inflammation. P2X7 is highly expressed in human AAA specimen, as well as in experimental murine AAA lesions (both CaCl2- and Angiotensin II-induced AAA models), and it mainly confines in macrophages. Furthermore, P2X7 deficiency or pharmacological inhibition with its antagonist could significantly attenuate aneurysm formation in experimental murine AAA models, while P2X7 agonist could promote AAA development. The caspase-1 activity, matrix metalloproteinase (MMP) activity, reactive oxygen species (ROS) production and pro-inflammatory gene expression were significantly reduced in experimental AAA lesions in mice with P2X7 deficiency or inhibition. Mechanistically, macrophage P2X7 can mediate the activation of NLRP3 inflammasome and activate its downstream caspase-1 to initiate the pyroptosis pathway. After caspase-1 activation, it further cleaves pro-interleukin (IL)-1ß and gasdermin D (GSDMD). Consequently, the N-terminal fragment of GSDMD forms pores on the cell membrane, leading to macrophage pyroptosis and release of the pro-inflammatory factor IL-1ß. The resulting vascular inflammation further leads to the upregulation of MMP and ROS, thereby promoting AAA development. In summary, these data identify P2X7-mediated macrophage pyroptosis signaling pathway as a novel contributory mechanism of AAA formation.

An Overview of Antitumour Activity of Polysaccharides.

Cancer incidence and mortality are rapidly increasing worldwide; therefore, effective therapies are required in the current scenario of increasing cancer cases. Polysaccharides are a family of natural polymers that hold unique physicochemical and biological properties, and they have become the focus of current antitumour drug research owing to their significant antitumour effects. In addition to the direct antitumour activity of some natural polysaccharides, their structures offer versatility in synthesizing multifunctional nanocomposites, which could be chemically modified to achieve high stability and bioavailability for delivering therapeutics into tumor tissues. This review aims to highlight recent advances in natural polysaccharides and polysaccharide-based nanomedicines for cancer therapy.

[Retracted] Upregulation of microRNA­25­3p inhibits proliferation, migration and invasion of osteosarcoma cells in vitro by directly targeting SOX4.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the cell migration assay data shown in Figs. 3B and 5C were strikingly similar to data that had appeared in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a satisfactory reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 16: 4293­4300, 2017; DOI: 10.3892/mmr.2017.7103].

THAP9-AS1 Promotes Tumorigenesis and Reduces ROS Generation through the JAK2/STAT3 Signaling Pathway by Increasing SOCS3 Promoter Methylation in Osteosarcoma.

Increasing studies have demonstrated that dysfunction of long noncoding RNAs (lncRNAs) plays critical roles in the development of human cancers. THAP9-AS1 has been reported to be dysregulated and associated with tumor progression in some cancers. However, the function and mechanism of THAP9-AS1 in osteosarcoma (OS) remain unclear. In the present study, we found that the expression of THAP9-AS1 was significantly upregulated in OS tissues and associated with the advanced stage of tumors and poor prognosis of patients. Blast comparison results showed that the SOCS3 promoter region and THAP9-AS1 had base complementary pairing binding sites. The interactions between THAP9-AS1, DNA methyltransferases (DNMTs), and SOCS3 were assessed by RIP and ChIP assays. The results of methylation-specific PCR (MSP) and bisulfite sequencing PCR (BSP) validated that THAP9-AS1 enhanced the methylation level of the SOCS3 promoter. The mRNA levels of SOCS3 in OS cells could be reversed by the demethylation agent 5-aza-2'-deoxycytidine. The mRNA expression of SOCS3 was downregulated in OS tissues and negatively correlated with THAP9-AS1 expression in tumors. Moreover, the western blot and immunofluorescence (IF) assay data showed that THAP9-AS1 activated the JAK2/STAT3 signaling pathway by upregulating p-JAK2 and p-STAT3 and the nuclear translocation of p-STAT3. Functionally, ectopic expression of THAP9-AS1 promoted cell proliferation, migration, and invasion and inhibited apoptosis, and this phenomenon could be reversed by SOCS3. Introduction of the JAK/STAT inhibitor AG490 partially abolished the stimulative effect of THAP9-AS1 on cellular processes. In addition, THAP9-AS1 decreased oxidative stress by reducing reactive oxygen species (ROS) and enhancing the mitochondrial membrane potential of OS cells via the SOCS3/JAK2/STAT3 pathway. Stable overexpression of THAP9-AS1 contributed to tumor growth and metastasis in vivo. In total, our findings suggested that upregulation of THAP9-AS1 might recruit DNMTs to epigenetically inhibit SOCS3, thereby activating the JAK2/STAT3 signaling pathway and oncogenesis of OS. These results provide novel insights for the understanding of OS progression.

Next generation of anti-PD-L1 Atezolizumab with enhanced anti-tumor efficacy in vivo.

FDA-approved anti-PD-L1 antibody drug Atezolizumab is a human IgG1 without glycosylation by an N297A mutation. Aglycosylation of IgG1 has been used to completely remove the unwanted Fc-mediated functions such as antibody-dependent cytotoxicity (ADCC). However, aglycosylated Atezolizumab is very unstable and easy to form aggregation, which causes quick development of anti-drug antibody (ADA) in 41% of Atezolizumab-treated cancer patients, eventually leading to loss of efficacy. Here, we report the development of the anti-PD-L1 antibody drug Maxatezo, a glycosylated version of Atezolizumab, with no ADCC activity, better thermo-stability, and significantly improved anti-tumor activity in vivo. Using Atezolizumab as the starting template, we back-mutated A297N to re-install the glycosylation, and inserted a short, flexible amino acid sequence (GGGS) between G237 and G238 in the hinge region of the IgG1 heavy chain. Our data shows that insertion of GGGS, does not alter the anti-PD-L1's affinity and inhibitory activity, while completely abolishing ADCC activity. Maxatezo has a similar glycosylation profile and expression level (up to 5.4 g/L) as any normal human IgG1. Most importantly, Maxatezo's thermal stability is much better than Atezolizumab, as evidenced by dramatic increases of Tm1 from 63.55 °C to 71.01 °C and Tagg from 60.7 °C to 71.2 °C. Furthermore, the levels of ADA in mice treated with Maxatezo were significantly lower compared with animals treated with Atezolizumab. Most importantly, at the same dose (10 mg/kg), the tumor growth inhibition rate of Maxatezo was 98%, compared to 68% for Atezolizumab.

Streptococcus gordonii infectious endocarditis presenting as a neurocysticercosis mimic - A rare manifestation.

Infective endocarditis (IE) usually presents with nonspecific signs and symptoms, which delay diagnosis and proper treatment. Here, we describe a patient with initial clinical and radiological features compatible with neurocysticercosis who was later found to have IE. Furthermore, the patient course was complicated by multiple neurological complications (brain abscess, meningitis, infected intracranial aneurysm, subarachnoid hemorrhage and hemorrhage), and patient ultimately deceased. To our knowledge, an IE case mimicking neurocysticercosis and progressing with prominent and complicated neurological manifestations has not been previously reported. We therefore describe the challenges of neurocysticercosis diagnosis based on serum ELISA and radiological findings. For patient diagnosed as neurocysticercosis, clinical follow-up is recommended and presence of systemic symptoms should be red flags for another underlying disease.

Rational design of peptides for identification of linear epitopes and generation of neutralizing monoclonal antibodies against DKK2 for cancer therapy.

Dickkopf-related protein 2 (DKK2)is a member of the Dickkopf family in Wnt signaling pathway. Recently, we found that antibodies against DKK2 could activate natural killer (NK) and CD8+ T cells in tumors and inhibit tumor growth. In this paper, we report the rational design of peptides for identification of linear epitopes and generation of neutralizing monoclonal anti-DKK2 antibodies. To break the immune tolerance, we designed and chemically synthesized six peptides corresponding to different regions of DKK2 as immunogens and found five of them could generate mouse polyclonal antibodies that can bind to the active recombinant human DKK2 protein. Neutralizing mouse monoclonal antibodies (5F8 and 1A10) against human DKK2 were successfully developed by immunizing the mice with two different peptides (34KLNSIKSSL42 and 240KVWKDATYS248) conjugated to Keyhole limpet hemocyanin (KLH). The monoclonal antibodies not only abolish DKK2's suppression of Wnt signaling in vitro but also inhibits tumor growth in vivo. Currently, those two mAbs are undergoing humanization as immunotherapy candidates and may offer a new drug for treatment of human cancers.

Novel strategy for expression and characterization of rabies virus glycoprotein.

Rabies is a fatal zoonosis which could affect all mammals. Glycoprotein (G protein) from the rabies virus plays an important role in the binding of virus to target cells. However, expression of the G protein with native conformation has been a great challenge for many years. In this study, we solved this problem by replacing the original signal peptide of rabies virus G protein with the one from the heavy chain of human IgG. The expression levels of recombinant G protein dramatically increased from a few µg/L to 50 mg/L in the culture supernatants. The identity of the recombinant G protein was confirmed by western blotting using both 6XHis mAb 6E2 and rabies G protein mAb 7G3. The correct conformation of the recombinant G protein was shown by using rabies virus neutralizing antibodies. In addition, the recombinant G protein had immune-reactivities with mice sera raised against rabies vaccines and vice versa. Taken together, our data suggested that by replacing the signal peptide, the expression level of the G protein with native conformation could be significantly improved. This would help the development of a rabies subunit vaccine, structural studies of rabies G protein, elucidation of the signal pathway of RABV infection.

Production of monoclonal antibodies for measuring Avastin and its biosimilar by Sandwich ELISA.

The development of Bevacizumab (Avastin) biosimilar products has grown rapidly over the last ten years as the original Avastin's patent will expire soon. The approval of Avastin biosimilars requires the demonstration of similarity between the biosimilar and the reference product. To support pre-clinical and clinical studies, pharmacokinetic (PK) assays are required to measure the biosimilar and Avastin with comparable precision and accuracy. The PK assay of Avastin employed by Genentech was a Sandwich ELISA which could detect the total drug concentration. However, it was developed in-house and not commercially available. Therefore, in most of the Avastin biosimilar pre-clinical studies, the antibody drug concentrations were measured using an indirect ELISA against coated VEGF, which could only measure the free instead of the total antibody drugs. It failed the essential requirement to develop the biosimilars. In this study, we reported the generation of mouse monoclonal antibodies (mAbs) that specifically recognize Avastin in a VEGF non-competitive manner. Using a pair of non-VEGF competing anti-Avastin mAbs, a Sandwich ELISA was developed with a lower limit of quantitation (LLOQ) at 400 ng/mL and upper limit of quantitation (ULOQ) at 12800 ng/mL. The assay validation was carried out with serum samples from monkey treated with Avastin biosimilar at seven different time points. Our data showed that the Sandwich ELISA kit we developed is sensitive, simple, reproducible and ready for use in human clinical trials.

A simple and cost-effective assay for measuring anti-drug antibody in human patients treated with Adalimumab.

It has been reported that 90% of the anti-drug antibody (ADA) to Adalimumab in human patients bound to the TNF-binding area, resulted in the annual loss of responses to Adalimumab up to 24%. It is of urgency to develop a cost-effective and easy-to-use ADA diagnostic kit for diagnosis of potential drug-resistance in patients treated with Adalimumab in clinic hospitals to avoid the tremendous economic and human costs to patients and health-care providers. In this study, we reported the generations of mouse monoclonal and monkey polyclonal antibodies against Adalimumab as assay standards and positive quality controls respectively. A Bridging ELISA assay was successfully developed with a limit of detection (LOD) between 22-80ng/ml. The preliminary validation of assay was carried out first with 50 normal human sera, further validated by screening the ADA in 192 serum samples from monkeys treated with or without Adalimumab. Our data showed that the Bridging ELISA kit is very sensitive, highly specific and ready for study in human clinic trials.

Upregulation of microRNA-25-3p inhibits proliferation, migration and invasion of osteosarcoma cells in vitro by directly targeting SOX4.

Osteosarcoma (OS) is among the most common primary tumors of bone tissue, and occurs primarily in children and young adults. Despite the development of novel therapeutic approaches, the prognosis of OS remains poor. MicroRNAs (miRNAs) are involved in the development and progression of various types of human cancer and may have potential as novel therapeutic targets for cancer treatment. The present study aimed to investigate the expression and biological functions of miRNA­25­3p in OS, and explore the molecular mechanisms underlying its actions. In the present study, miRNA­25­3p was detected in OS tissues and cell lines. The functional roles of miRNA­25­3p in OS cells were evaluated using a Cell Counting Kit 8 assay and cellular migration and invasion assays. The molecular mechanisms underlying the tumor­suppressing roles of miRNA­25­3p in OS were explored using bioinformatics analysis, luciferase reporter assay, western blotting and the reverse transcription­quantitative polymerase chain reaction. The expression of miRNA­25­3p was revealed to be downregulated in OS tissues and cell lines compared with non­tumor bone tissues and normal osteoblasts, respectively. miRNA­25­3p overexpression was demonstrated to significantly suppress the proliferation, migration and invasion of OS cells in vitro. In addition, sex­determining region­related high mobility group box (SOX) 4 was identified as a direct target gene of miRNA­25­3p, and was further investigated. Similarly to miRNA­25­3p overexpression, SOX4 knockdown was demonstrated to suppress OS cell proliferation, migration and invasion. Furthermore, SOX4 expression was revealed to be significantly upregulated in OS tissues compared with in adjacent non­tumor bone tissues, and Spearman's correlation analysis indicated a negative correlation between SOX4 mRNA and miRNA­25­3p expression levels in OS tissues. The present findings suggested that miRNA­25­3p may act as a tumor suppressor by targeting SOX4 expression in bone tissue. Therefore, miRNA­25­3p may have potential as a novel therapeutic target for the treatment of patients with OS.

Long non-coding RNA PVT1 promotes glycolysis and tumor progression by regulating miR-497/HK2 axis in osteosarcoma.

Cancer cells usually utilize glucose as a carbon source for aerobic glycolysis, a phenomenon known as the Warburg effect. Increasing studies have shown that PVT1 (a long non-coding RNA, lncRNA) functions as critical regulator of multiple cancers. However, it remains totally unknown whether and how PVT1 regulates glucose metabolism in OS cells. In this study, we found that the expression of PVT1 were specifically increased in OS cells and tissues, and the upregulated PVT1 indicated poor prognosis. Glucose uptake, lactate production, and the expression of HK2 in OS cells were increased by overexpression of PVT1, while decreased by PVT1 knockdown. We further fund that PVT1 acted as molecular sponge to repress miR-497. Inhibition of miR-497 promoted glucose consumption and lactate production, phenomenon could be reversed by PVT1 silencing. Moreover, HK2 was a direct target of miR-497 and overexpression of HK2 attenuated the suppressive effect of miR-497 on glycolysis. Functionally, knockdown of PVT1 exerted tumor-suppressive effect by suppressing cell proliferation, cell cycle progression, and invasion in vitro, whereas miR-497 inhibitor partially abolished the inhibition effect of si-PVT1. Overexpression of HK2 attenuated the miR-497 induced inhibition of cell growth and motility. Taken together, these findings suggested that PVT1 contributes to OS cell glucose metabolism, cell proliferation, and motility through the miR-497/HK2 pathway, and revealed a novel relation between lncRNA and the alteration of glycolysis in OS cells.