Organisms co-expressing oncogenic Myc & oncogenic Ras are 100 fold more likely to produce tumors than do organism expressing either oncogene by itself. Explain the molecular biology that underlies this synergistic effect.
Myc is an oncogene that is often found to be overexpressed in several cancer cells. Ras is another transcription factor like Myc which on overexpression, can drive tumor formation. One of the major focal points of Myc ans Ras signalling is Cyclin D1 and CDK4. Cyclin D1 functions to drive the G1-to-S phase progression of the cell cycle with it's associated kinase CDK4.
Ras activates the expression of Cyclin D1 but inhibits the expression of CDK4. On the other hand, Myc activates the expression of of CDK4 but inhibits Cyclin D1. Both of these are needed to check each other's overactivity, and proceed the cell cycle in proper speed and manner. If only Myc or Ras is mutated, the other is still present to prevent the overactivity of Cyclin D1-CDK4. But when both Myc and Ras are mutated and converted to oncogenes, this checking power ends and both Cyclin D1 and CDK4 is over-expressed, leading to uncontrolled cell proliferation and tumor formation.
Organisms co-expressing oncogenic Myc & oncogenic Ras are 100 fold more likely to produce tumors than...
10. Write a one-page summary of the attached paper? INTRODUCTION Many problems can develop in activated sludge operation that adversely affect effluent quality with origins in the engineering, hydraulic and microbiological components of the process. The real "heart" of the activated sludge system is the development and maintenance of a mixed microbial culture (activated sludge) that treats wastewater and which can be managed. One definition of a wastewater treatment plant operator is a "bug farmer", one who controls the aeration...