Mitochondrial protein LETM1 and its-mediated CTMP are potential therapeutic targets for endometrial cancer

Area of Science:

• Mitochondrial biology
• Oncology
• Molecular mechanisms of cancer

Background:

• Leucine zipper/EF hand-containing transmembrane-1 (LETM1) is a mitochondrial protein with largely unknown functions in endometrial cancer.
• Carboxy-terminal modulator protein (CTMP) is implicated in cancer progression, but its role alongside LETM1 in endometrial cancer is unexplored.

Purpose of the Study:

• To investigate the role of LETM1 in endometrial cancer.
• To elucidate the underlying molecular mechanisms, focusing on the interaction with CTMP.
• To assess the therapeutic potential of targeting LETM1 and CTMP.

Main Methods:

• Immunohistochemistry to assess LETM1 and CTMP expression in human endometrial tissues.
• Gene silencing (siRNA) of LETM1 and CTMP in endometrial cancer cell lines (ISK, KLE).
• In vitro assays for cell viability, colony formation, migration, and invasion.
• In vivo xenograft mouse model to evaluate antitumor effects.
• CTMP overexpression studies to confirm regulatory relationships.

Main Results:

• LETM1 and CTMP expression were significantly elevated in endometrial cancer tissues compared to normal and atypical hyperplastic tissues.
• LETM1 and CTMP were also upregulated in endometrial cancer cell lines.
• Silencing LETM1 or CTMP reduced cancer cell viability, proliferation, migration, and invasion in vitro.
• LETM1/CTMP silencing decreased tumor growth and volume in a xenograft mouse model.
• LETM1 silencing led to CTMP downregulation, and CTMP overexpression reversed the effects of LETM1 silencing, indicating a regulatory axis.

Conclusions:

• LETM1 and CTMP are oncogenic factors in endometrial cancer, with elevated expression correlating with disease progression.
• LETM1 inhibition suppresses endometrial cancer malignancy, partly by downregulating CTMP.
• Targeting the LETM1/CTMP pathway presents a potential therapeutic strategy for endometrial cancer.