8. Cancer cells secretes chemicals such as VEGF for angiogenesis, whose target cells are
   (1) B-cells (2) Platelets
   (3) RBC                                              (4) Endothelial cells

SEO Article: VEGF and Its Target Cells in Cancer-Driven Angiogenesis

Cancer progression is heavily reliant on angiogenesis—the formation of new blood vessels—to supply tumors with oxygen and nutrients. A critical factor secreted by cancer cells to induce this process is VEGF (Vascular Endothelial Growth Factor). Understanding which cells VEGF targets provides insight into how tumors manipulate their microenvironment to grow and metastasize.

What is VEGF?

VEGF is a potent signaling protein primarily involved in promoting the growth of blood vessels. It is secreted by cancer cells especially under hypoxic (low oxygen) conditions to stimulate angiogenesis, a process vital for tumor survival and expansion. VEGF belongs to a family of proteins that bind to specific receptors on the surface of target cells.

VEGF Target Cells: Endothelial Cells

The primary target of VEGF in angiogenesis is endothelial cells, which line the interior surface of blood vessels. VEGF binds to tyrosine kinase receptors (mainly VEGFR-1 and VEGFR-2) on endothelial cells and activates a cascade of intracellular signals that promote:

• Endothelial cell proliferation

• Migration toward the tumor

• Formation of tubular structures forming new capillaries

• Survival and inhibition of apoptosis, sustaining the new vessels

This targeted action on endothelial cells enables the formation of new blood vessels feeding the tumor with nutrients and oxygen, facilitating its growth and providing pathways for metastasis.

Why Other Cells Are Not Primary VEGF Targets

• B-cells (Option 1) are immune cells involved in antibody production but are not directly stimulated by VEGF for new blood vessel growth.

• Platelets (Option 2) participate in clotting and can release angiogenic factors but are not the direct target of VEGF released by tumors.

• Red Blood Cells (RBCs) (Option 3) carry oxygen but lack nuclei and receptors to respond to VEGF signaling.

Thus, VEGF’s specific action on endothelial cells (Option 4) is the key driver in angiogenesis related to cancer.

Importance of VEGF-Induced Angiogenesis in Cancer

The new vessels generated through VEGF signaling enable tumors to overcome size limitations imposed by diffusion of oxygen and nutrients. This vascular network supports rapid cancer cell growth and provides routes for cancer cells to enter the bloodstream, leading to metastasis.

Because of this critical role, VEGF and its receptors are primary targets of anti-angiogenic therapies designed to inhibit tumor growth by starving it of its blood supply.

Conclusion

Cancer cells secrete chemicals such as VEGF to promote angiogenesis, and the target cells of VEGF are endothelial cells lining blood vessels. This interaction is essential for tumor vascularization and progression, making VEGF-endothelial signaling a focal point in cancer biology and treatment.