Guigao Lin

Serum microRNA-155 as a potential biomarker to track disease in breast cancer.

Background One major impediment to improving the management of breast cancer is the current lack of tumor marker with sufficient sensitivity and specificity. A growing body of evidence implicates the diagnostic potential of circulating miRNAs in cancer detection. MiR-155 plays an important role in the pathogenesis of breast cancer. However, the level of circulating miR-155 and its clinical relevance are not well established. The objective of the current study was to learn more about serum miR-155 in patients with breast cancer. Methodology/Principal Findings Using quantitative reverse transcription polymerase chain reaction (RT-qPCR), we demonstrated that serum miR-155 had significant increased levels in breast cancer patients (n = 103) compared with healthy subjects (n = 55) (p<0.001), which had a mean fold change of 2.94. Receiver operating characteristic (ROC) analysis revealed that miR-155 had considerable diagnostic accuracy, yielding an ROC-AUC (the areas under the ROC curve) of 0.801 (sensitivity 65.0%, specificity 81.8%). In addition, sera from a subset of breast cancer patients (n = 29) were collected after surgery and after four cycles of chemotherapy to evaluate the effects of clinical treatment on serum levels of candidate miRNAs. Surprisingly, a decreased level of serum miR-155 was found; whereas the concentrations of carbohydrate antigen 15-3 (CA15-3), carcinoembryonic antigen (CEA) and tissue polypeptide specific antigen (TPS) did not show this trend. Our results revealed that 79% patients showed response or stable disease after therapy had declined levels of serum miR-155. Conclusions/Significance Our results suggest that serum miR-155 is a potential biomarker to discriminate breast cancer patients from healthy subjects. For the first time, we demonstrated a declined trend of miR-155 after surgery and chemotherapy, which raises the possibility to use it as an indicator for treatment response.

Armored long non-coding RNA MEG3 targeting EGFR based on recombinant MS2 bacteriophage virus-like particles against hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most frequently diagnosed cancers worldwide. However, the treatment of patients with HCC is particularly challenging. Long non-coding RNA maternally expressed gene 3 (MEG3) has been identified as a potential suppressor of several types of tumors, but the delivery of long RNA remains problematic, limiting its applications. In the present study, we designed a novel delivery system based on MS2 virus-like particles (VLPs) crosslinked with GE11 polypeptide. This vector was found to be fast, effective and safe for the targeted delivery of lncRNA MEG3 RNA to the epidermal growth factor receptor (EGFR)-positive HCC cell lines without the activation of EGFR downstream pathways, and significantly attenuated both in vitro and in vivo tumor cell growth. Our study also revealed that the targeted delivery was mainly dependent on clathrin-mediated endocytosis and MEG3 RNA suppresses tumor growth mainly via increasing the expression of p53 and its downstream gene GDF15, but decreasing the expression of MDM2. Thus, this vector is promising as a novel delivery system and may facilitate a new approach to lncRNA based cancer therapy.

Multicolor flow cytometry analysis of the proliferations of T-lymphocyte subsets in vitro by EdU incorporation.

EdU (5‐ethynyl‐2′‐deoxyuridine) incorporation has proved advantageous in the studies of cell kinetics, DNA synthesis, and cellular proliferation in vitro and in vivo compared to [3H]thymidine incorporation and BrdU (5‐bromo‐2′‐deoxyuridine) incorporation. Here, we describe a method that combines EdU incorporation and immunostaining with flow cytometric analysis to detect the proliferations of T lymphocyte subsets in vitro and optimized the assays conditions. We found that the number of EdU+ cells were associated with EdU concentration, incubation time, and the volume of Click reaction solution, the best EdU concentration 10–50 μM, the optimal incubation time 8–12 h and the proper volume of Click volume 100 μl for labeling 1 × 106 lymphocytes. Fixation was better to be performed before permeabilization, not together with. Furthermore, the permeabilization detergent reagent, PBS with 0.05% saponin was better than Tris buffer saline (TBS) with 0.1% Triton X‐100. In addition, sufficient wash with PBS with 0.05% saponin has no influence on the staining of EdU+ cells. Also, the lymphocytes incorporating EdU could be stored at 4°C, −80°C, and in liquid nitrogen up to 21 days. The present study will aid in optimization of flow cytometry assay to detect the proliferations of T cell subsets by EdU incorporation and the labeling of cell surface antigens.

Application of CRISPR/Cas9 Technology to HBV

More than 240 million people around the world are chronically infected with hepatitis B virus (HBV). Nucleos(t)ide analogs and interferon are the only two families of drugs to treat HBV currently. However, none of these anti-virals directly target the stable nuclear covalently closed circular DNA (cccDNA), which acts as a transcription template for viral mRNA and pre-genomic RNA synthesis and secures virus persistence. Thus, the fact that only a small number of patients treated achieve sustained viral response (SVR) or cure, highlights the need for new therapies against HBV. The clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing system can specifically target the conserved regions of the HBV genome. This results in robust viral suppression and provides a promising tool for eradicating the virus. In this review, we discuss the function and application of the CRISPR/Cas9 system as a novel therapy for HBV.

Novel miR-122 delivery system based on MS2 virus like particle surface displaying cell-penetrating peptide TAT for hepatocellular carcinoma

Current treatments for hepatocellular carcinoma (HCC) have shown inadequate. MicroRNA-122 (miR-122) mediated RNA interference brings new prospects. A safe, efficient miRNA delivery system is an indispensable assurance. Previously, we developed an MS2 bacteriophage virus-like particle (VLP)-based microRNA delivery system crosslinked with the HIV TAT peptide, which served as an effective inhibitor in the treatments of systemic lupus erythematosus and osteoporosis. However, defects, such as low crosslinking efficiency, high cost, and potential toxicity of the crosslinking agent, needed to be confronted. Therefore, TAT peptide was designed to display on the surface of MS2 VLPs, instead of being chemically crosslinked, using the platform of phage surface display. The results reflected that MS2 VLPs displaying TAT could effectively penetrate the cytomembrane and deliver miR-122. Additionally, its inhibitory effects on HCC were significant in Hep3B, HepG2, and Huh7 cells and Hep3B related animal models. Thus, we have established a novel miR-122 delivery system based on MS2 VLPs surface displaying TAT peptide, which could effectively perform the function of penetrating cytomembrane and the inhibition of HCC.

Using a novel microRNA delivery system to inhibit osteoclastogenesis.

Previously, we developed a novel microRNA (miRNA) delivery system based on bacteriophage MS2 virus-like particles (MS2 VLPs). In this current study, we used this system to transport miR-146a into human peripheral blood mononuclear cells (PBMCs), and demonstrated the inhibition of osteoclastogenesis in precursors. Two cytokines, receptor activator of NF-κB ligand (RANKL), and macrophage-colony stimulating factor (M-CSF) were used to induce osteoclastogenesis. MS2 VLPs were transfected into PBMCs. qRT-PCR was applied to measure expression levels of miR-146a and osteoclast (OC)-specific genes. Western blot (WB) was conducted to evaluate miR-146a downstream target proteins: epidermal growth factor receptor (EGFR) and tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6). The formation and activity of OCs were assessed by cytochemical staining and bone resorption assay, respectively. In PBMCs treated with MS2-miR146a VLPs, qRT-PCR assays showed increased expression of miR-146a (p < 0.01) and decreased expression of all four OC-specific genes (p < 0.05). WB results indicated decreased expression of EGFR (p < 0.01) and TRAF6 (p < 0.05). The number of OCs decreased markedly and bone resorption assay demonstrated inhibited activity. This miR-146a delivery system could be applied to induce overexpression of miR-146a and to inhibit the differentiation and function of OCs.

Construction of Armored RNA Containing Long-Size Chimeric RNA by Increasing the Number and Affinity of the Pac Site in Exogenous RNA and Sequence Coding Coat Protein of the MS2 Bacteriophage

Objectives: To construct a one-plasmid expression system of the armored RNA containing long chimeric RNA byincreasing the number and affinity of the pac site. Methods: The plasmid pET-MS2-pac was constructedwith one C-variant pac site, and then the plasmid pM-CR-2C containing 1,891-bp chimeric sequences and two C-variant pac sites was produced. Meanwhile, three plasmids (pM-CR-C, pM-CR-2W and pM-CR-W) were obtained as parallel controls with a different number and affinity of the pac site. Finally, the armored RNA was expressed and purified. Results: The armored RNA with 1,891 bases target RNA was expressed successfully by the one-plasmid expression system with two C-variant pac sites, while for one pac site, no matter whether the affinity was changed or not, only the 1,200 bases target RNA was packaged. It was also found that the C-variant pac site could increase the expression efficiency of the armored RNA. The armored RNA with 1,891-bp exogenous RNA in our study showed the characterization of ribonuclease resistance and stability at different time points and temperature conditions. Conclusions: The armored RNA with 1,891 bases exogenous RNA was constructed and the expression system can be used as a platform for preparation of the armored RNA containing long RNA sequences.

Serological diagnosis of toxoplasmosis and standardization

Humans can be infected by the intracellular parasite Toxoplasma gondii, which causes toxoplasmosis, a common parasitic disease. Although the infection is generally asymptomatic for most adults, severe complications may occur in some individuals, especially women in early pregnancy. Serologic diagnosis is used as a routine practice to determine the immune status for infection by T. gondii. In this review, we attempt to provide an overview of the serological diagnosis of toxoplasmosis, including diagnostic strategy, current problems in detection with specific antibodies, and the standardization of T. gondii serological detection.

A New Type of Natural Bispecific Antibody With Potential Protective Effect in Hashimoto Thyroiditis

CONTEXT As a new antibody concept, natural bispecific antibodies (nBsAbs) have been detected in long-term passive immunization and some diseases, but their potential immunomodulatory role remains unclear. Hashimoto thyroiditis (HT) appears to fulfill the condition for nBsAb production but has not yet been characterized. OBJECTIVE The objective of the study was to identify a new nBsAb against thyroid peroxidase (TPO) and thyroglobulin (Tg) in HT patients and to preliminarily explore its immunomodulatory role. DESIGN, SETTING, AND PATIENTS Serum samples were obtained from 136 HT patients, 92 diseased controls, and 99 healthy controls for anti-TPO/Tg nBsAb detection. The relationship between anti-TPO/Tg nBsAb and other clinical parameters was also analyzed. MAIN OUTCOME MEASURES The anti-TPO/Tg nBsAb was detected using a double-antigen sandwich ELISA. Higher nBsAb levels were found to be associated with decreased inflammation in HT patients. RESULTS The prevalence of anti-TPO/Tg nBsAb in HT was 44.9% (61 of 136), significantly higher than that of diseased controls (2.2%, 2 of 92) (P < .0001) and healthy controls (0%, 0 of 99) (P < .0001). HT patients who were nBsAb positive were prone to have significantly lower levels of serum C-reactive protein and TNF-α compared with the nBsAb-negative individuals (P < .05). The serum amyloid A and interferon-γ levels also showed a similar trend in the two groups. The IgG subclass of anti-TPO/Tg nBsAb was IgG4. Further analysis showed a negative correlation between anti-TPO/Tg nBsAb and serum total IgG4 (r = -0.697, P = .025) in IgG4 thyroiditis patients. CONCLUSIONS A new type of nBsAb against TPO and Tg in HT patients is identified. Our data also indicate a protective effect of anti-TPO/Tg nBsAb in the pathogenesis of HT and extend prior knowledge about nBsAb in diseases.

Quantitative nucleic acid amplification by digital PCR for clinical viral diagnostics.

Abstract In the past few years, interest in the development of digital PCR (dPCR) as a direct nucleic acid amplification technique for clinical viral diagnostics has grown. The main advantages of dPCR over qPCR include: quantification of nucleic acid concentrations without a calibration curve, comparable sensitivity, superior quantitative precision, greater resistance to perturbations by inhibitors, and increased robustness to the variability of the target sequence. In this review, we address the application of dPCR to viral nucleic acid quantification in clinical applications and for nucleic acid quantification standardization. Further development is required to overcome the current limitations of dPCR in order to realize its widespread use for viral load measurements in clinical diagnostic applications.