No abstract

Systemic lupus erythematosus (SLE) has a strong but incompletely understood genetic architecture. We conducted an association study with replication in 4,492 SLE cases and 12,675 controls from six East-Asian cohorts, to identify novel and better localize known SLE susceptibility loci. We identified 10 novel loci as well as 20 known loci with genome-wide significance. Among the novel loci, the most significant was GTF2IRD1-GTF2I at 7q11.23 (rs73366469, Pmeta=3.75×10−117, OR=2.38), followed by DEF6, IL12B, TCF7, TERT, CD226, PCNXL3, RASGRP1, SYNGR1 and SIGLEC6. We localized the most likely functional variants for each locus by analyzing epigenetic marks and gene regulation data. Ten putative variants are known to alter cis- or trans-gene expression. Enrichment analysis highlights the importance of these loci in B- and T-cell biology. Together with previously known loci, the explained heritability of SLE increases to 24%. Novel loci share functional and ontological characteristics with previously reported loci, and are possible drug targets for SLE therapeutics.

Tumor targetability and site-specific drug release of therapeutic nanoparticles are key factors for effective cancer therapy. In this study, poly(ethylene glycol) (PEG)-conjugated hyaluronic acid nanoparticles (P-HA-NPs) were investigated as carriers for anticancer drugs including doxorubicin and camptothecin (CPT). P-HA-NPs were internalized into cancer cells (SCC7 and MDA-MB-231) via receptor-mediated endocytosis, but were rarely taken up by normal fibroblasts (NIH-3T3). During in vitro drug release tests, P-HA-NPs rapidly released drugs when incubated with cancer cells, extracts of tumor tissues, or the enzyme Hyal-1, which is abundant in the intracellular compartments of cancer cells. CPT-loaded P-HA-NPs (CPT-P-HA-NPs) showed dose-dependent cytotoxicity to cancer cells (MDA-MB-231, SCC7, and HCT 116) and significantly lower cytotoxicity against normal fibroblasts (NIH-3T3) than free CPT. Unexpectedly, high concentrations of CPT-P-HA-NPs demonstrated greater cytotoxicity to cancer cells than free CPT. An in vivo biodistribution study indicated that P-HA-NPs selectively accumulated into tumor sites after systemic administration into tumor-bearing mice, primarily due to prolonged circulation in the blood and binding to a receptor (CD44) that was overexpressed on the cancer cells. In addition, when CPT-P-HA-NPs were systemically administrated into tumor-bearing mice, we saw no significant increases in tumor size for at least 35 days, implying high antitumor activity. Overall, P-HA-NPs showed promising potential as a drug carrier for cancer therapy.

The assembly of inflammatory lesions in rheumatoid arthritis is highly regulated and typically leads to the formation of lymphoid follicles with germinal center (GC) reactions. We used microdissection of such extranodal follicles to analyze the colonizing T cells. Although the repertoire of follicular T cells was diverse, a subset of T cell receptor (TCR) sequences was detected in multiple independent follicles and not in interfollicular zones, suggesting recognition of a common antigen. Unexpectedly, the majority of shared TCR sequences were from CD8 T cells that were highly enriched in the synovium and present in low numbers in the periphery. To examine their role in extranodal GC reactions, CD8 T cells were depleted in human synovium-SCID mouse chimeras. Depletion of synovial CD8 T cells caused disintegration of the GC-containing follicles. In the absence of CD8 T cells, follicular dendritic cells disappeared, production of lymphotoxin-α1β2 markedly decreased, and immunoglobulin (Ig) secretion ceased. Immunohistochemical studies demonstrated that these CD8 T cells accumulated at the edge of the mantle zone. Besides their unique localization, they were characterized by the production of interferon (IFN)-γ, lack of the pore-forming enzyme perforin, and expression of CD40 ligand. Perifollicular IFN-γ+ CD8 T cells were rare in secondary lymphoid tissues but accounted for the majority of IFN-γ+ cells in synovial infiltrates. We propose that CD8+ T cells regulate the structural integrity and functional activity of GCs in ectopic lymphoid follicles.

DNA-methyltransferase-3B (DNMT3B) plays an important role in the generation of aberrant methylation in carcinogenesis. Polymorphisms and haplotypes of the DNMT3B gene may influence DNMT3B activity on DNA methylation, thereby modulating the susceptibility to lung cancer. To test this hypothesis, we investigated the association of the -283T > C (from exon 1A transcription start site) and -579G > T (from exon 1B transcription start site) polymorphisms in DNMT3B promoter, and their haplotypes with the risk of lung cancer in a Korean population. The DNMT3B genotype was determined in 432 lung cancer patients and 432 healthy controls that were frequency-matched for age and sex. Individuals with at least one -283T allele were at a significantly decreased risk of adenocarcinoma (AC) and small cell carcinoma (SM) [adjusted odds ratio (OR) = 0.48, 95% confidence interval (CI) = 0.28-0.82, P = 0.007; and adjusted OR = 0.47, 95% CI = 0.24-0.93, P = 0.03, respectively] compared with those harboring a -283CC genotype. Individuals with at least one -579G allele were also at a significantly decreased risk of AC and SM (adjusted OR = 0.47, 95% CI = 0.28-0.81, P = 0.006; and adjusted OR = 0.51, 95% CI = 0.26-0.99, P = 0.048, respectively) compared with those having a -579TT genotype. The -283T allele was linked with the -579G allele, and haplotype -283T/-579G was associated with a significantly decreased risk of AC (adjusted OR = 0.48, 95% CI = 0.29-0.81, P = 0.006) as compared with haplotype -283C/-579T. In a promoter assay, carriage of the -283T allele showed a significantly lower promoter activity ( approximately 50%) compared with the -283C allele (P < 0.001), but the -579G > T polymorphism did not have an affect on the DNMT3B promoter activity. These results suggest that the DNMT3B -283T > C polymorphism influences DNMT3B expression, thus contributing to the genetic susceptibility to lung cancer.