Long Noncoding RNA ASLNC07322 Functions in VEGF-C Expression Regulated by Smad4 during Colon Cancer Metastasis

Area of Science:

• Oncology
• Molecular Biology
• Cancer Genetics

Background:

• Smad4 gene alterations are linked to colon cancer progression.
• The precise regulatory mechanism between Smad4 and vascular endothelial growth factor C (VEGF-C) in colon cancer remains unclear.
• VEGF-C plays a crucial role in tumor angiogenesis and metastasis.

Purpose of the Study:

• To elucidate the regulatory mechanisms of Smad4 on VEGF-C expression in colon cancer.
• To investigate the role of microRNA-128-3p (miR-128-3p) and long noncoding RNA ASLNC07322 in the Smad4-VEGF-C axis.
• To explore therapeutic strategies targeting these pathways.

Main Methods:

• Investigated Smad4's effect on miR-128-3p transcription.
• Analyzed Smad4/Smad3 complex binding to the VEGF-C gene promoter.
• Assessed the role of lncRNA ASLNC07322 as a sponge for miR-128-3p.
• Evaluated the combined effect of ASLNC07322 knockdown and Smad4 overexpression in vitro and in vivo.

Main Results:

• Smad4 increases miR-128-3p transcription, negatively correlating with VEGF-C.
• Smad4/Smad3 complex positively regulates VEGF-C during metastasis by binding to its promoter.
• lncRNA ASLNC07322, upregulated in metastatic colon cancer, sponges miR-128-3p, increasing VEGF-C.
• ASLNC07322 controls the switch between Smad4/miR-128-3p/VEGF-C and Smad4/VEGF-C pathways.
• Combined ASLNC07322 knockdown and Smad4 overexpression inhibited tumor growth and lymphangiogenesis.

Conclusions:

• Two distinct pathways, Smad4/miR-128-3p/VEGF-C and Smad4/VEGF-C, are involved in colon cancer progression.
• ASLNC07322 acts as a critical switch regulating these pathways.
• Targeting ASLNC07322 and Smad4 offers a potential therapeutic strategy for colon cancer metastasis.