Treatment of those pets with an investigational PI3K inhibitor did lead to rapid tumor regression. Since previous studies suggested that PI3K inhibition might block K-Ras-induced tumor development also, the investigators also examined the PI3K inhibitor in mice with K-Ras-stimulated tumors. That treatment was ineffective, but since K-Ras activates the MEK/ERK signalling pathway also, the experts treated the animals with an investigational MEK inhibitor and with a combination of both drugs. Treatment with the MEK inhibitor only caused just a modest decrease in tumor size, but combined treatment with both brokers caused the K-Ras-stimulated lung tumors to practically vanish. Related StoriesViralytics enters into clinical trial collaboration agreement with MSDSausages With Antioxidants From Berries TO AVOID CancerOvarian cancer patients with a brief history of oral contraceptive use have better outcomes For several years we’ve known that K-Ras activates two major pathways – the PI3K pathway and the MEK/MAPK pathway – and these pathways have many redundant functions in tumor growth and survival, says Lewis Cantley, PhD, of the BIDMC Cancer Center, one of the study’s co-corresponding authors.This delay, which a replication is called by them refractory period, had never been seen in mammalian advancement. The researchers made use of a novel cell labeling technique that allows them to view the fates of individual cells throughout multiple rounds of cell divisions. Although the cell labeling technique have been described previously by other groupings, our group was the first to use it over long periods of time, said Kushner. By providing rats with a timed sequence of colored dyes in their drinking water, the researchers were able to discover discrete beta cells in the rat pancreas, shining in single shades that indicated a sequence of cell divisions. In contrast, the rapidly dividing cells in the rats’ intestine demonstrated blended shades, indicating that that they had divided multiple occasions from specialized cells, possibly from adult stem cells.