Regulatory functions of trehalose-6-phosphate synthase in the chitin biosynthesis pathway in Tribolium castaneum (Coleoptera: Tenebrionidae) revealed by RNA interference.

RNA interference (RNAi) is a very effective technique for studying gene function and may be an efficient method for controlling pests. Trehalose-6-phosphate synthase (TPS), which plays a key role in the synthesis of trehalose and insect development, was cloned in Tribolium castaneum (Herbst) (TcTPS) and the putative functions were studied using RNAi via the injection of double-stranded RNA (dsRNA) corresponding to conserved TPS and trehalose-6-phosphate phosphatase domains. Expression analyses show that TcTPS is expressed higher in the fat body, while quantitative real-time polymerase chain reaction results show that the expression of four trehalase isoforms was significantly suppressed by dsTPS injection. Additionally, the expression of six chitin synthesis-related genes, such as hexokinase 2 and glutamine-fructose-6-phosphate aminotransferase, was suppressed at 48 and 72 h post-dsTPS-1 and dsTPS-2 RNA injection, which were two dsTPS fragments that had been designed for two different locations in TcTPS open reading frame, and that trehalose content and trehalase 1 activity decreased significantly at 72 h post-dsRNA injection. Furthermore, T. castaneum injected with dsTPS-1 and dsTPS-2 RNA displayed significantly lower levels of chitin and could not complete the molting process from larvae to pupae, revealing abnormal molting phenotypes. These results demonstrate that silencing TPS gene leads to molting deformities and high mortality rates via regulation of gene expression in the chitin biosynthetic pathway, and may be a promising approach for pest control in the future.

Expression level of lipoprotein lipase in Chinese patients with chronic lymphocytic leukemia and its correlation with other prognostic factors.

Chronic lymphocytic leukemia (CLL) is the most common adult form of leukemia in the Western world, however, infrequent in the Eastern. It shows a remarkable heterogeneity, with some patients having an almost normal lifespan, others surviving only several years after diagnosis despite intensive therapy. To investigate lipoprotein lipase (LPL) expression level in Chinese patients with CLL and its correlation with other prognostic factors, including immunoglobulin heavy-chain variable region (IgVH) mutation status, Binet stages, ZAP-70 protein and CD38 expression level, semiquantitative RT-PCR was used to detect LPL expression in peripheral blood samples of 58 Chinese patients with CLL. LPL expression level was significantly correlated with IgVH mutational status (r = 0.348, P = 0.010), Binet stages (r = 0.276, P = 0.036), ZAP-70 protein (r = 0.431, P = 0.001) and CD38 (r = 0.546, P < 0.001). Patients with unmutated IgVH genes had higher expression of LPL than patients with IgVH mutations. The higher expression level of LPL was also associated with higher level of ZAP-70 and CD38, and more aggressive Binet stage. We also analyzed LPL expression in different cytogenetic subgroups. Higher LPL level was found in patients with unfavorable cytogenetic aberrations (deletion in 17p13 or 11q22) in contrast to lower level in good risk cytogenetics (deletion in 13q as the sole abnormality) (r = 0.404, P = 0.002). It was showed that LPL expression correlates with IgVH mutational status and other clinical or laboratory prognostic factors, and might be applied for the assessment of prognosis in patients with CLL.