Although universal vaccination against HAV is not currently indicated, selective vaccination of the high-risk population, based on their serological evidence of HAV antibody, would be a rational and cost-effective approach.

Osteosarcoma (OS) is an aggressive and highly metastatic form of primary bone cancer affecting young children and adults. Previous studies have shown that hypomethylation of critical genes is driving metastasis. Here, we examine whether hypermethylation treatment can block OS growth and pulmonary metastasis. Human OS cells LM-7 and MG-63 were treated with the ubiquitous methyl donor S-adenosylmethionine (SAM) or its inactive analog S-adenosylhomocystine (SAH) as control. Treatment with SAM resulted in a dose-dependent inhibition of tumor cell proliferation, invasion, cell migration, and cell cycle characteristics. Inoculation of cells treated with 150 μmol/L SAM for 6 days into tibia or via intravenous route into Fox Chase severe combined immune deficient (SCID) mice resulted in the development of significantly smaller skeletal lesions and a marked reduction in pulmonary metastasis as compared to control groups. Epigenome wide association studies (EWAS) showed differential methylation of several genes involved in OS progression and prominent signaling pathways implicated in bone formation, wound healing, and tumor progression in SAM-treated LM-7 cells. Real-time polymerase chain reaction (qPCR) analysis confirmed that SAM treatment blocked the expression of several prometastatic genes and additional genes identified by EWAS analysis. Immunohistochemical analysis of normal human bone and tissue array from OS patients showed significantly high levels of expression of one of the identified gene platelet-derived growth factor alpha (PDGFA). These studies provide a possible mechanism for the role of DNA demethylation in the development and metastasis of OS to provide a rationale for the use of hypermethylation therapy for OS patients and identify new targets for monitoring OS development and progression.

Hepatitis B virus (HBV) is the major causative agent of chronic liver complications including cirrhosis and hepatocellular carcinoma (HCC). Individuals infected with HBV show a wide spectrum of disease manifestations ranging from asymptomatic carriers to HCC. TLR3 is part of the innate immune system that recognizes double-stranded RNA (dsRNA) and provides early immune response to exogenous antigens. The genetic polymorphisms such as single nucleotide polymorphisms (SNPs) in the TLR3 could be considered as factors for the susceptibility to viral pathogens including HBV. Due to lack of knowledge on the role of TLR3 polymorphisms in HBV infection, this study investigated the distribution of nine SNPs in the TLR3 gene and its association with Saudi Arabian patients infected with HBV. A total of 707 patients and 600 uninfected controls were examined for different parameters including the nine SNPs (rs5743311, rs5743312, rs1879026, rs5743313, rs5743314, rs5743315, rs111611328, rs78726532 and a newly identified SNP located at position 184322913 of chr4). The association analysis confirmed that only one SNP, rs1879026 (G/T), showed a significant difference (P = 0.0480; OR = 0.809, 95% CI = 0.655-0.999) in the distribution between HBV carriers and uninfected controls. While, the rest of the SNPs showed no significant association with regards to HBV infection or in the progression to cirrhosis of the liver and HCC. Furthermore, haplotype analysis revealed that one haplotype GCGA (rs1879026, rs5743313, rs5743314, and rs5743315, respectively), was associated significantly with HBV infection in this population. These findings indicate that genetic variations in the TLR3 gene could affect the outcome of HBV infection among Saudis.

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An unusual human rotavirus strain B219 was detected in a stool specimen from a 65-year old patient with diarrhea in Bangladesh during April 2002. Cloning and sequence analysis of five genes of the B219 strain indicated that this virus is genetically closely related to the ADRV-N strain, which caused an adult diarrhea outbreak in China, but distinct from groups A, B, and C rotaviruses known to cause diarrheal diseases in humans. Accordingly, rotavirus strains B219 and ADRV-N were considered to belong to a novel group of human rotavirus, and the ADRV-N-like novel human rotaviruses were suggested to be distributed to a geographically wider area.

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The chiral monometallic Cu(II) (1) and Zn(II) (2) and heterobimetallic Cu(II)-Sn(IV) and Zn(II)-Sn(IV) complexes with tridentate chiral Schiff base -ONO-ligand in the presence of nitrogen donor heterocyclic ligand imidazole; were prepared and characterized by various physico-chemical and spectroscopic methods. Preliminary complex-DNA interaction studies employing optical methods revealed that 3 displayed a higher propensity towards the drug target DNA double helix and recommended predominantly an electrostatic mode of interaction as well as a groove binding affinity of the complex with CT-DNA. This was quantified by Kb and KSV values of complexes 1-4, which demonstrated a multifold increase in complex 3 binding to CT DNA and clearly demonstrates its potency to act as a chemotherapeutic agent. Furthermore, the gel electrophoretic patterns of supercoiled pBR322 DNA with varying concentrations of complex 3 exhibits the ability to cleave DNA and follow a freely diffusible radical mechanism. The antiproliferative effects of complex 3 on human hepatoma cancer cells (Huh7) was investigated. Human Topo I inhibition assay by complex 3 was performed and results confirmed significantly good activity at lower concentrations than some of the classical Topo I inhibitors. Additionally, complex 3 was investigated for the expression of MMP-2 and TGF-β by real time PCR. The cellular uptake of complex 3 by HeLa cells was studied by confocal microscopy.