Functional role of the long noncoding RNA X-inactive specific transcript in leiomyoma pathogenesis

Area of Science:

• Reproductive biology
• Molecular genetics
• RNA biology

Background:

• Leiomyoma, a common gynecological tumor, is characterized by abnormal extracellular matrix accumulation.
• The role of long noncoding RNAs (lncRNAs) in leiomyoma pathogenesis is not fully understood.

Purpose of the Study:

• To investigate the expression and functional significance of the lncRNA XIST in human leiomyoma.
• To elucidate the molecular mechanisms by which XIST influences leiomyoma development.

Main Methods:

• Quantitative real-time PCR and Western blotting to assess gene and protein expression.
• Cell culture models (3D spheroid) and transfection techniques (siRNA, overexpression) to manipulate XIST levels.
• RNA immunoprecipitation assays to confirm molecular interactions.

Main Results:

• XIST expression is significantly elevated in leiomyoma compared to normal myometrium.
• XIST levels are modulated by hormones (estradiol, progesterone) and SP1 transcription factor.
• XIST knockdown inhibits proliferation and upregulates miR-29c and miR-200c, decreasing COL1A1, COL3A1, and FN1.
• XIST overexpression in myometrium cells represses miR-29c/miR-200c and increases COL1A1, COL3A1, and FN1.
• XIST acts as a molecular sponge for miR-29c and miR-200c, with enhanced activity in leiomyoma.

Conclusions:

• Elevated XIST in leiomyoma contributes to fibroid pathology by downregulating tumor-suppressive microRNAs (miR-29c, miR-200c).
• This leads to increased expression of extracellular matrix genes (COL1A1, COL3A1, FN1), promoting fibroid growth.
• XIST is a potential therapeutic target for managing leiomyoma.