Luteolin Decreases Epidermal Growth Factor Receptor-Mediated Cell Proliferation and Induces Apoptosis in Glioblastoma Cell Lines.

Glioblastomas are a subtype of gliomas, which are the most aggressive and deadly form of brain tumours. The epidermal growth factor receptor (EGFR) is over-expressed and amplified in glioblastomas. Luteolin is a common bioflavonoid found in a variety of fruits and vegetables. The aim of this study was to explore the molecular and biological effects of luteolin on EGF-induced cell proliferation and the potential of luteolin to induce apoptosis in glioblastoma cells. In vitro cell viability assays demonstrated that luteolin decreased cell proliferation in the presence or absence of EGF. Immunoblots revealed that luteolin decreased the protein expression levels of phosphorylated Akt, mTOR, p70S6K and MAPK in the presence of EGF. Furthermore, our results revealed the ability of luteolin to induce caspase and PARP cleavages in glioblastoma cells in addition to promoting cell cycle arrest. Our results demonstrated that luteolin has an inhibitory effect on downstream signalling molecules activated by EGFR, particularly the Akt and MAPK signalling pathways, and provided a rationale for further clinical investigation into the use of luteolin as a therapeutic molecule in the management of glioblastoma.

Soybean natural cross-pollination rates under field conditions.

Recent concerns regarding within-crop transgene flow stimulated this research to update natural cross-pollination rates in conventional sowings of modern soybean [Glycine max (L.) Merr.] in the Mississippi Delta. Two experiments were conducted in 2001 and 2002 using two soybean cultivars, "Pace" (white-flowered) and "DP3588" (purple-flowered), selected for their equivalent flowering dates. The experiments utilized the dominance of purple flower color over white flower color to identify natural cross-pollinations. In the first experiment, 12 rows of Pace (white-flowered) flanked on each side by four rows of DP3588 (purple flowered) were sown on 10 May 2001. Seed were harvested by row from each of the Pace rows and examined for natural cross-pollinations in the next generation. In total, 73 512 potential hybrid plants were examined and natural cross-pollination rates ranged from 0.41% at 0.9 m from the pollen source to 0.03% at 5.4 m from the pollen source. These values were consistent with values previously reported in the literature. In the second experiment, seed of Pace and DP3588 were alternately sown 15.2 cm apart within a row in 2001. At maturity, 167 Pace plants (white-flowered) were harvested and a total of 19,151 progeny were evaluated for natural cross-pollinations in the next generation. The progeny of 56 (33.5%) of the 167 parent plants showed no evidence of natural cross-pollination. The progeny of the remaining 111 plants exhibited natural cross-pollination rates ranging from 0.65 to 6.32% and averaged 1.8%. The maximum rates reported here are considerably higher than most previously reported rates. The results of these two experiments highlight the potential for within-crop transgene flow in soybean.