Species-specific function of microRNA-7702 in human colorectal cancer cells via targeting TADA1

Area of Science:

• Molecular Oncology
• Cancer Genomics
• Epigenetics

Background:

• Colorectal cancer (CRC) progression involves complex molecular mechanisms, including the dysregulation of microRNAs (miRNAs).
• While many miRNAs are studied for their roles in CRC invasion and metastasis, less common miRNAs and their targets remain underexplored.
• Identifying novel miRNAs and their functional targets is crucial for understanding CRC pathogenesis and developing therapeutic strategies.

Purpose of the Study:

• To identify novel microRNAs involved in colorectal adenocarcinoma (CRC) invasion and metastasis using TCGA data.
• To investigate the functional role of the candidate microRNA, miR-7702, and its potential target gene, TADA1, in CRC.
• To elucidate the species-specific regulatory mechanism of miR-7702 on TADA1 in human CRC cells.

Main Methods:

• Differential expression analysis of miRNAs in colon and rectal adenocarcinoma using TCGA data.
• Bioinformatic prediction and database analysis (Oncomine) to identify TADA1 as a target of miR-7702.
• Dual-luciferase reporter assays, gene expression manipulation (transfection), and cell migration/invasion assays in human CRC cell lines.

Main Results:

• miR-7702 was identified as a differentially expressed miRNA in stages N0 and N1/N2 CRC.
• A negative correlation between miR-7702 and TADA1 expression was observed in CRC tissues and cell lines.
• Overexpression of miR-7702 suppressed human CRC cell migration and invasion by directly inhibiting TADA1, with no observed effect in mouse cells.

Conclusions:

• miR-7702 functions as a tumor suppressor in colorectal cancer by inhibiting cell migration and invasion.
• The tumor-suppressive role of miR-7702 is mediated through the direct inhibition of its target gene, TADA1.
• The functional activity of miR-7702 in regulating TADA1 appears to be specific to human colorectal cancer cells.