Translation of the efficacy of antibody-drug conjugates from preclinical to clinical using a semimechanistic PK/PD model: A case study with RC88.

Three semimechanistic pharmacokinetic/pharmacodynamic (PK/PD) models, Simeoni, Jumbe, and Hybrid, were used for the efficacy translation of RC88 from preclinical to clinical. RC88 is a mesothelin-targeting antibody-drug conjugate for malignant solid tumor. In the preclinical study, the relationship between PKs and PDs was determined using the xenograft mouse model derived from ovarian cancer and lung cancer cell lines. A secondary parameter representing the efficacy index of the drug, termed as tumor static concentration (TSC), was calculated using the three semimechanistic PK/PD models. A mechanism-based target-mediated drug disposition model was used to predict the human PKs. TSC from mice and predicted human PK were integrated to predict human efficacy dose. Results showed that 2 cell lines were sensitive to drugs, and the predicted efficacy dose was between 0.82 and 1.96 mg/kg q1w.

MDSCs drive the process of endometriosis by enhancing angiogenesis and are a new potential therapeutic target.

Endometriosis affects women of reproductive age via unclear immunological mechanism(s). Myeloid-derived suppressor cells (MDSCs) are a heterogeneous group of myeloid cells with potent immunosuppressive and angiogenic properties. Here, we found MDSCs significantly increased in the peripheral blood of patients with endometriosis and in the peritoneal cavity of a mouse model of surgically induced endometriosis. Majority of MDSCs were granulocytic, produced ROS, and arginase, and suppressed T-cell proliferation. Depletion of MDSCs by antiGr-1 antibody dramatically suppressed development of endometrial lesions in mice. The chemokines CXCL1, 2, and 5 were expressed at sites of lesion while MDSCs expressed CXCR-2. These CXC-chemokines promoted MDSC migration toward endometriotic implants both in vitro and in vivo. Also, CXCR2-deficient mice show significantly decreased MDSC induction, endometrial lesions, and angiogenesis. Importantly, adoptive transfer of MDSCs into CXCR2-KO mice restored endometriotic growth and angiogenesis. Together, this study demonstrates that MDSCs play a role in the pathogenesis of endometriosis and identifies a novel CXC-chemokine and receptor for the recruitment of MDSCs, thereby providing a potential target for endometriosis treatment.

MicroRNAs associated with the pathogenesis of multiple sclerosis.

Multiple sclerosis (MS) is not only an autoimmune disease in which autoreactive immune cells against myelin damage axons and nerves in the central nervous system, but also a neurodegenerative disease, in which progressive loss of structure and function of neurons occurs. The mechanisms of MS pathogenesis have not been fully understood. It has been reported that miRNAs may play a critical role in MS pathogenesis. In this review, we have extensively discussed the alterations in the expression of miRNAs detected in patients with MS. The dysregulated miRNAs have been shown to be associated with the pathogenesis of MS. We suggest that such dysregulated miRNAs may potentially be used as biomarkers in the diagnosis of MS, to discover new therapeutic targets for MS treatment, and to predict prognostic markers in responses to MS treatment.

[Investigation for use of The Name and Location of Acupoints(GB/T 12346-2006), national standard].

To understand the use in recent 10 years of The Name and Location of Acupoints(GB/T 12346-2006),a standard of The People's Republic of China,so as to provide the evidence for its further establishment and revision,we investigated and analyzed the application of The Name and Location of Acupoints through relevant literature and the textbook. It is found that making use of the standard is being realized in various types of articles and it is described in almost all the textbooks. Implementing the standard intensively promotes the standardization of acupuncture-moxibustion education and clinical manipulation as well as the academic exchange domestically and overseas. In turn,its scientificalness and authority are further strengthened.

Expression, regulation and function of MicroRNAs in endometriosis.

Endometriosis (EMS), characterized by the presence and growth of functional en do met rial-like tissues outside the uterine cavity, is a common and benign gyneco logical disorder with a poorly understood and somewhat enigmatic etiopathogenesis and pathophysiology. MicroRNAs (miRNAs) are single-stranded 19-25 nucleotide-long RNAs and have an important role in post-transcriptional gene silencing by base pairing with target mRNAs. Recent research has shown that miRNAs and their target mRNAs are differentially expressed in endometriosis and other disorders of the female reproductive system. In this paper, we review the recent progress in understanding the roles of miRNAs in endometriosis, and specific miRNAs as biomarkers and therapeutic targets for endometriosis.

Expression, regulation and function of microRNAs in multiple sclerosis.

MicroRNAs (miRNAs) are single-stranded 19-25 nucleotide-long RNAs and have an important role in post-transcriptional gene silencing. It has been demonstrated that miRNAs are dysregulated in patients with multiple sclerosis (MS). For instance, miR-21, miR-142-3p, miR-146a, miR-146b, miR-155 and miR-326 were up-regulated in both peripheral blood mononuclear cells (PBMCs) and brain white matter lesions from MS patients and mouse model as well. These up-regulated miRNAs may be used as a signature for MS and play critical roles in MS pathogenesis. Moreover, miR-15a, miR-19a, miR-22, miR-210 and miR-223 were up-regulated in both regulatory T cells (Tregs) and other samples such as plasma, blood cells, PBMCs and brain white matter tissues from MS patients, suggesting that these up-regulated miRNAs and Tregs may also play a role in MS pathogenesis. Contrarily, other miRNAs such as miR-15a, miR-15b, miR-181c and miR-328 were down-regulated in MS. Drugs such as interferon-ß and glatiramer acetate for MS treatment may regulate miRNA expression and thus have benefits for MS patients. The dysregulated miRNAs such as miR-155 and miR-326 may be used as diagnostic markers and therapeutic targets for MS.

Inhibition of Kaposi's sarcoma-associated herpesvirus lytic replication by HIV-1 Nef and cellular microRNA hsa-miR-1258.

UNLABELLED: Kaposi's sarcoma-associated herpesvirus (KSHV) is causally linked to several AIDS-related malignancies, including Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease. The interaction of human immunodeficiency virus type 1 (HIV-1) and KSHV has a central role in promoting the aggressive manifestations of AIDS-KS. We have previously shown that negative factor (Nef), a secreted HIV-1 protein, synergizes with KSHV viral interleukin-6 (vIL-6) to promote angiogenesis and tumorigenesis by activating the AKT pathway (X. Zhu, et al., Oncogene, 22 April 2013, http://dx.doi.org/10.1038/onc.2013.136). Here, we further demonstrated the role of soluble and ectopic Nef in the regulation of KSHV latency. We found that both soluble Nef protein and ectopic expression of Nef by transfection suppressed the expression of KSHV viral lytic mRNA transcripts and proteins and the production of infectious viral particles. MicroRNA (miRNA) microarray analysis identified a number of Nef-regulated miRNAs. Bioinformatics and luciferase reporter analyses showed that one of the Nef-upregulated miRNAs, cellular miRNA 1258 (hsa-miR-1258), directly targeted a seed sequence in the 3' untranslated region (UTR) of the mRNA encoding the major lytic switch protein (RTA), which controls KSHV reactivation from latency. Ectopic expression of hsa-miR-1258 impaired RTA synthesis and enhanced Nef-mediated inhibition of KSHV replication, whereas repression of hsa-miR-1258 has the opposite effect. Mutation of the seed sequence in the RTA 3'UTR abolished downregulation of RTA by hsa-miR-1258. Collectively, these novel findings demonstrate that, by regulating cellular miRNA, Nef may inhibit KSHV replication to promote viral latency and contribute to the pathogenesis of AIDS-related malignancies. IMPORTANCE: This study found that Nef, a secreted HIV-1 protein, suppressed KSHV lytic replication to promote KSHV latency. Mechanistic studies indicated that a Nef-upregulated cellular miRNA, hsa-miR-1258, inhibits KSHV replication by directly targeting a seed sequence in the KSHV RTA 3'UTR. These results illustrate that, in addition to viral miRNAs, cellular miRNAs also play an important role in regulating the life cycle of KSHV. Overall, this is the first study to report the involvement of Nef in KSHV latency, implying its likely important role in the pathogenesis of AIDS-related malignancies.

Cellular microRNAs 498 and 320d regulate herpes simplex virus 1 induction of Kaposi's sarcoma-associated herpesvirus lytic replication by targeting RTA.

Kaposi's sarcoma-associated herpesvirus (KSHV) infection was necessary but not sufficient for KS development without other cofactors. We have previously reported that herpes simplex virus (HSV)-1 was an important cofactor that reactivated KSHV from latency by inducing the expression of KSHV replication and transcription activator (RTA), the lytic switch protein. Here, we further investigated the possible cellular microRNAs (miRNAs) involved in regulation of RTA during HSV-1-induced KSHV replication. The differential profiles of miRNAs expression between Mock- and HSV-1-infected body cavity-based lymphoma (BCBL-1) cells were identified by miRNA microarray analysis. Bioinformatics and luciferase reporter analyses showed that two of the HSV-1-downregulated cellular miRNAs, miR-498 and miR-320d, directly targeted the 3' untranslated region (UTR) of KSHV RTA. As a result, overexpression of these two miRNAs significantly inhibited HSV-1-induced KSHV replication, whereas repression of these miRNAs with specific suppressors enhanced HSV-1-mediated KSHV replication. In addition, miR-498 or miR-320d alone, without HSV-1 infection, regulated KSHV replication in BCBL-1 cells. Finally, bioinformatics Gene Ontology (GO) analysis indicated that targets of HSV-1-regulated miRNAs were enriched for proteins, whose roles were involved in protein binding, enzyme activity, biological regulation, and several potential signaling pathways including transforming growth factor (TGF)-ß were likely to participate in HSV-1-induced KSHV replication. Collectively, these novel findings demonstrated that host-encoded miR-498 and miR-320d regulated HSV-1 induction of KSHV lytic replication by targeting RTA, which provided further insights into the molecular mechanisms controlling KSHV lytic replication.

Herpes simplex virus type 2 triggers reactivation of Kaposi's sarcoma-associated herpesvirus from latency and collaborates with HIV-1 Tat.

Kaposi's sarcoma-associated herpesvirus (KSHV) infection was necessary but not sufficient for Kaposi's sarcoma (KS) development without other cofactors. Previously, we identified that both human immunodeficiency type 1 (HIV-1) Tat and herpes simplex virus 1 (HSV-1) were important cofactors reactivating KSHV from latency. Here, we further investigated the potential of herpes simplex virus 2 (HSV-2) to influence KSHV replication and examined the role of Tat in this procedure. We demonstrated that HSV-2 was a potentially important factor in the pathogenesis of KS, as determined by production of lytic phase mRNA transcripts, viral proteins and infectious viral particles in BCBL-1 cells. These results were further confirmed by an RNA interference experiment using small interfering RNA targeting KSHV Rta and a luciferase reporter assay testing Rta promoter-driven luciferase activity. Mechanistic studies showed that HSV-2 infection activated nuclear factor-kappa B (NF-κB) signaling pathway. Inhibition of NF-κB pathway enhanced HSV-2-mediated KSHV activation, whereas activation of NF-κB pathway suppressed KSHV replication in HSV-2-infected BCBL-1 cells. Additionally, ectopic expression of Tat enhanced HSV-2-induced KSHV replication. These novel findings suggest a role of HSV-2 in the pathogenesis of KS and provide the first laboratory evidence that Tat may participate HSV-2-mediated KSHV activation, implying the complicated pathogenesis of acquired immunodeficiency syndrome (AIDS)-related KS (AIDS-KS) patients.

A cluster of transcripts encoded by KSHV ORF30-33 gene locus.

Kaposi's sarcoma-associated herpesvirus ORF30-33 locus encodes four genes with unknown functions. We performed transcriptional mapping of these genes. Northern-hybridization, 5'- and 3'-rapid amplification of cDNA ends, and DNA sequencing identified four transcripts of 3.7, 3.6, 2.7, and 1.4 kb, none of which has alternative splicing. While all transcripts have the same termination site, their start sites vary. All transcripts are not expressed or only weakly expressed in latent cells but can be chemically induced. The 3.7 and 3.6 kb transcripts contain all four genes and are sensitive to cycloheximide (CH) but resistant to phosphonoacetic acid (PAA), indicating that they are early lytic transcripts. The 2.7 kb transcript contains ORF32 and ORF33 genes while the 1.4 kb transcript contains the ORF33 gene. Both transcripts are sensitive to CH and PAA, indicating that they are late lytic transcripts. Furthermore, we identified four promoters with functional TATA boxes, none of which is directly transactivated by RTA. Examination of the 5' untranslated region of ORF31 failed to identify any functional internal ribosome entry sites. These results define the transcriptional patterns of the ORF30-33 locus, which should help the delineation of its function.

Activation of PI3K/AKT and ERK MAPK signal pathways is required for the induction of lytic cycle replication of Kaposi's sarcoma-associated herpesvirus by herpes simplex virus type 1.

BACKGROUND: Kaposi's sarcoma-associated herpesvirus (KSHV) is causally linked to several acquired immunodeficiency syndrome-related malignancies, including Kaposi's sarcoma (KS), primary effusion lymphoma (PEL) and a subset of multicentric Castleman's disease. Regulation of viral lytic replication is critical to the initiation and progression of KS. Recently, we reported that herpes simplex virus type 1 (HSV-1) was an important cofactor that activated lytic cycle replication of KSHV. Here, we further investigated the possible signal pathways involved in HSV-1-induced reactivation of KSHV. RESULTS: By transfecting a series of dominant negative mutants and protein expressing constructs and using pharmacologic inhibitors, we found that either Janus kinase 1 (JAK1)/signal transducer and activator of transcription 3 (STAT3) or JAK1/STAT6 signaling failed to regulate HSV-1-induced KSHV replication. However, HSV-1 infection of BCBL-1 cells activated phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB, also called AKT) pathway and inactivated phosphatase and tensin homologue deleted on chromosome ten (PTEN) and glycogen synthase kinase-3ß (GSK-3ß). PTEN/PI3K/AKT/GSK-3ß pathway was found to be involved in HSV-1-induced KSHV reactivation. Additionally, extracellular signal-regulated protein kinase (ERK) mitogen-activated protein kinase (MAPK) pathway also partially contributed to HSV-1-induced KSHV replication. CONCLUSIONS: HSV-1 infection stimulated PI3K/AKT and ERK MAPK signaling pathways that in turn contributed to KSHV reactivation, which provided further insights into the molecular mechanism controlling KSHV lytic replication, particularly in the context of HSV-1 and KSHV co-infection.