Isolinderalactone inhibits glioblastoma cell supernatant-induced angiogenesis.

Glioblastoma multiforme (GBM) is the most frequently occurring malignant brain tumor in adults and is characterized by a high degree of vascularization. Glioblastoma cells communicate with their microenvironment and stimulate blood vessel formation to support tumor progression. It has previously been reported that isolinderalactone induces apoptosis in GBM cells and suppresses the growth of glioblastoma xenograft tumors in vivo. Furthermore, isolinderalactone has been shown to inhibit the hypoxia-driven upregulation of vascular endothelial growth factor (VEGF) in U-87 GBM cells and strongly reduce VEGF-triggered angiogenesis in vitro and in vivo. In the present study, the direct angiogenic effect of GBM and the effect of isolinderalactone on tumor angiogenesis were investigated. Culture supernatants were obtained from U-87 cells under normoxic or hypoxic conditions to provide normoxic conditioned medium (NCM) and hypoxic conditioned medium (HCM) respectively. The NCM and HCM were each used to treat to human brain microvascular endothelial cells (HBMECs), and their effects were observed using wounding migration and tube formation assays. HCM increased the migration and capillary-like tube formation of HBMECs when compared with NCM, and treatment with isolinderalactone suppressed the HCM-driven angiogenesis in vitro. Additionally, isolinderalactone decreased HCM-triggered angiogenic sprouting in HBMECs in a 3D microfluidic device after the application of an HCM-containing interstitial fluid flow. Furthermore, isolinderalactone strongly reduced HCM-triggered angiogenesis in an in vivo Matrigel plug assay in mice. These findings provide evidence of angiogenesis inhibition by isolinderalactone, and demonstrate the anti-angiogenic effect of isolinderalactone against the direct angiogenic effect of GBM tumor cells.

Gene flow from herbicide-tolerant GM rice and the heterosis of GM rice-weed F2 progeny.

Gene flow from genetically modified (GM) crops to non-GM cultivars or weedy relatives may lead to the development of more aggressive weeds. We quantified the amount of gene flow from herbicide-tolerant GM rice (Protox GM, derived from the cultivar Dongjin) to three cultivars (Dongjin, Aranghyangchal and Hwaseong) and a weedy rice line. Gene flow frequency generally decreased with increasing distance from the pollen donor. At the shortest distance (0.5 m), we observed a maximum frequency (0.039%) of gene flow. We found that the cultivar Dongjin received the greatest amount of gene flow, with the second being weedy rice. Heterosis of F2 inbred progeny was also examined between Protox GM and weedy rice. We compared growth and reproduction between F2 progeny (homozygous or hemizygous for the Protox gene) and parental rice lines (GM and weedy rice). Here, transgene-homozygous F2 progeny was significantly taller and produced more seeds than the transgene-hemizygous F2 progeny and parental lines. Although the gene flow frequency was generally low, our results suggest that F2 progeny between GM and weedy relatives may exhibit heterosis.

Evidence to support two conspecific cytological races on Anopheles aconitus in Thailand.

Iso-female lines (isolines) of Anopheles aconitus collected from Mae Hong Son, Phet Buri, and Chiang Mai Provinces were successfully identified to karyotypic forms. The results of identification revealed that An. aconitus Form B (X1, X2, Y2) was obtained from four and 48 isolines in Phet Buri and Chiang Mai Provinces, respectively, and Form C (X1, X2, Y3) was recovered from three and 41 isolines in Mae Hong Son and Chiang Mai Provinces, respectively. When comparing band to band on the same arm of ovarian nurse cell polytene chromosomes of An. aconitus Form B (Phet Buri: four isolines) and C (Mae Hong Son: three isolines, Chiang Mai: 20 isolines) to the standard chromosome mapping of An. aconitus Form B (Chiang Mai: 20 isolines), no major chromosomal rearrangements that related to the karyotype variations were demonstrated. The investigations on allelic frequencies of 4th stage larvae and adult females of three (Form C: Mae Hong Son), four (Form B: Phet Buri), 41 (Form C: Chiang Mai) and 48 (Form B: Chiang Mai) isolines suggested that An. aconitus Form B and C of all strains have similar allelic frequencies. This was observed at 10 isoenzymes 16 loci in 4th stage larvae, and 11 isoenzymes 13 loci in adult females. Hybridization tests among the four laboratory-raised isolines of An. aconitus Form B (Chiang Mai and Phet Buri) and C (Chiang Mai and Mae Hong Son) were employed by induced copulation. The results of crosses indicated that they were genetically compatible, providing viable progeny and completely synaptic salivary gland polytene chromosomes. The complete sequences ofrDNA internal-transcribed spacer two (ITS2) and partial sequences of mitochondrial cytochrome c oxidase subunit I and II (COI and COII) from genomic DNA of 12 isolines of An. aconitus Form B and C were identified. Total sequence lengths (ITS2+COI+COII) of An. aconitus isolines varied from 1550bp to 1556bp. Conspecific relationships between the two An. aconitus forms were well supported by low values of intraspecific distances (ranged from 0.1% to 1.0%) and genetic differentiation (d(xy): 0.01322) between the two forms. Based on evidence of no pre- and post-mating isolations, and nearly identical of DNA sequences of ITS2, COI and COII regions between An. aconitus Form B and C, we conclude that they are conspecific cytological races in the Thai population.