Solvent Effect on Dative and Ionic Bond Strengths: A Unified Theory from Potential Analysis and Valence-Bond Computations.

Solvent molecules interact with a solute through various intermolecular forces. Here we employed a potential energy surface (PES) analysis to interpret the solvent-induced variations in the strengths of dative (Me3NBH3) and ionic (LiCl) bonds, which possess both ionic and covalent (neutral) characteristics. The change of a bond is driven by the gradient (force) of the solvent-solute interaction energy with respect to the focused bond length. Positive force shortens the bond length and increases the bond force constant, leading to a blue-shift of the bond stretching vibrational frequency upon solvation. Conversely, negative force elongates the bond, resulting in a reduced bond force constant and red-shift of the stretching vibrational frequency. The different responses of Me3NBH3 and LiCl to solvation are studied with valence bond (VB) theory, as Me3NBH3 and LiCl are dominated by the neutral covalent VB structure and the ionic VB structure, respectively. The dipole moment of an ionic VB structure increases along the increasing bond distance, while the dipole moment of a neutral covalent VB structure increases with the decreasing bond distance. The roles of the dominating VB structures are further examined by the geometry optimizations and frequency calculations with the block-localized wavefunction (BLW) method.

LncRNA GHET1 promotes esophageal squamous cell carcinoma cells proliferation and invasion via induction of EMT.

BACKGROUND: Recent studies have shown that long noncoding RNA (lncRNA) gastric carcinoma highly expressed transcript 1 (GHET1) was involved in the progression of tumors. However, the role of GHET1 in esophageal squamous cell carcinoma (ESCC) remains unclear. METHODS: The expression of lncRNA GHET1 was examined in 55 paired ESCC tissues and adjacent nontumor tissues. Molecular and cellular techniques were used to explore the role of GHET1 on ESCC cells. RESULTS: Our data showed that GHET1 expression was significantly increased in ESCC tissues and cell lines. High GHET1 expression in ESCC tissues was significantly associated with poor differentiation, advanced tumor nodes metastasis stage, and lymph node metastasis. GHET1 showed high sensitivity and specificity for diagnosing ESCC. Our data from in vitro assays showed that GHET1 inhibition suppressed ESCC cells proliferation, migration, and invasion, and induced cells apoptosis. Furthermore, western blot showed that GHET1 inhibition significantly decreased the expression of vimentin and N-cadherin while it increased the expression of E-cadherin. CONCLUSIONS: Our study indicates that GHET1 acts as an oncogene in ESCC and may represent a novel therapeutic target for the treatment of ESCC patients.

Association of insulin-like growth factor I gene polymorphisms with the risk of osteoporosis in a Chinese population.

Osteoporosis is a systemic metabolic and serious skeletal disease commonly observed among the elderly. Insulin-like growth factors (IGFs) are critical regulators for bone cell function. We estimated the role of IGF-I rs35767, rs2288377 and rs5742612 polymorphisms in the susceptibility to osteoporosis in a population of China, and assessed gene-environment interactions. A total of 346 patients with osteoporosis and 346 controls were enrolled. Genotyping of IGF-I rs35767, rs2288377 and rs5742612 was amplified and performed with the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The TA and AA genotypes displayed elevated risk of developing osteoporosis (TA vs TT: OR=1.54, 95% CI=1.11-2.15; AA vs TT: OR=3.65, 95% CI=2.09-6.37). Compared with TT individuals, individuals with the TA+AA genotype had a substantial increased susceptibility to osteoporosis (OR=1.80, 95% CI=1.31-2.46). In recessive model, the AA genotype of rs2288377 displayed 2.89 folds risk of osteoporosis (adjusted OR=2.89, 95% CI=1.70-4.89). A significant negative interaction was found between IGF-I rs2288377 and BMD levels for femoral neck (r=-0.14, P<0.001), total hip (r=-0.09, P<0.001) and trochanter (r=-0.13, P<0.001). In conclusion, we suggest that IGF-I rs2288377 polymorphism had a strong influence on osteoporosis susceptibility in this Chinese population.

MiRNA-155 promotes proliferation by targeting caudal-type homeobox 1 (CDX1) in glioma cells.

MicroRNAs (miRNAs) play important roles in the tumorigenesis of glioma. Recent studies showed that miR-155 expression was increased in types of cancer, including glioma. However, the underlying mechanism of miR-155 on glioma is still unclear. In the present study, expression of miR-155 and caudal-type homeobox 1 (CDX1) was determined in glioma tissues by qRT-PCR, and the regulatory axis was further studied in glioma cells. We showed that miR-155 expression was significantly increased in glioma tissues while CDX1 expression was decreased. Correlation analysis revealed that miR-155 was negatively correlated with CDX1 expression in glioma tissues. Moreover, Kaplan-Meier analysis indicated that patients with high miR-155 expression had a poor overall survival. In addition, our results showed that the translation of CDX1 expression could be suppressed by miR-155 mimics. And miR-155 mimics promoted glioma cell proliferation could be reversed by CDX1 overexpression. In vivo assay, we showed that miR-155 overexpression promoted the progress of tumor formation. Therefore, we suggested that miR-155 might promote glioma cell growth partially by targeting CDX1, which provided a novel therapeutic strategy for glioma patients.