Beclin-1 expression levels across primary, recurrent, and lymph node metastasis tumors show what trend?

• A. Beclin-1 levels are highest in primary tumors.
• B. Beclin-1 levels increase with tumor progression, being lowest in primary tumors and highest in LN metastases.
• C. Beclin-1 levels are highest in recurrent tumors.
• D. Beclin-1 levels show no clear trend.

Answer: (B)

Beclin-1 is a pivotal regulator of autophagy, a process that helps cancer cells cope with stress during progression and metastasis. When autophagy supports survival in more advanced disease, cells in recurrent tumors or metastatic sites can show higher Beclin-1 expression than those in the primary tumor. This leads to a pattern where Beclin-1 levels are lowest in primary tumors and progressively higher in recurrent and especially in lymph node metastases, reflecting the greater reliance on autophagy to thrive in the challenging environments cells face during spread. If autophagy is more active in metastasis, that explains why lymph node metastases would exhibit the highest Beclin-1 levels. The other scenarios—highest levels in primary tumors, highest in recurrent tumors, or no clear trend—do not align with the idea that autophagy aids survival as cancer progresses and disseminates.