This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Which of the following is not a feature of malignant transformation by cultured cells? 
Select and explain. 
A. Increased cell density, B. Loss of anchorage, C. Increased requirement for growth factors, D. Alterations of cytoskeletal structures
C: Increased requirement for growth factors
Answer: C: Increased requirement for growth factors 
Explanation: When malignant transformation occur in cultured cells, their requirement for growth factors does not increase. On the contrary it decreases. The process of malignant transformation is associated with a stable, heritable loss of requirement of cultured cells for growth factors.Initial normal cell lines are fully dependent on growth factors and hormones for their growth. Once malignant transformation occurs, they become fully independent from hormones and growth factors. Ref: Robbins Pathologic Basis of Disease, 7th Edition, Pages 293-4; Harper Biochemistry, 26th Edition, Page 654