Tumor angiogenesis can be affected by which of the following factors?

• A. Secretion of vascular endothelial growth factor (VEGF)
• B. Decreased glycolysis in tumor cells
• C. Enhanced DNA repair mechanisms
• D. Increased lysosomal enzyme activity

Answer: (A)

Verified step by step guidance

1. Understand the concept of tumor angiogenesis: Tumor angiogenesis refers to the process by which tumors stimulate the formation of new blood vessels to supply oxygen and nutrients, enabling their growth and survival.
2. Identify the key factor involved in angiogenesis: Vascular endothelial growth factor (VEGF) is a signaling protein that plays a critical role in promoting angiogenesis by stimulating endothelial cell proliferation and migration.
3. Analyze the options provided: Evaluate each option to determine its relevance to angiogenesis. For example, secretion of VEGF directly promotes angiogenesis, while decreased glycolysis, enhanced DNA repair mechanisms, and increased lysosomal enzyme activity are not directly related to the formation of new blood vessels.
4. Focus on VEGF: Recognize that VEGF secretion is a well-established mechanism by which tumors induce angiogenesis, making it the most relevant factor among the options provided.
5. Conclude the reasoning: Based on the biological role of VEGF in angiogenesis, determine that the secretion of VEGF is the correct answer to the question.