Iminodibenzyl redirected cyclooxygenase-2 catalyzed dihomo-γ-linolenic acid peroxidation pattern in lung cancer

Area of Science:

• Oncology
• Biochemistry
• Molecular Biology

Background:

• Cyclooxygenase-2 (COX-2) is upregulated in cancer and targeted by inhibitors, but these have limited efficacy and severe side effects.
• The rationale for COX-2 inhibitors involves suppressing omega-6 polyunsaturated fatty acid (PUFA) peroxidation, crucial in cancer development.
• Redox imbalance contributes to COX-2 upregulation, making it a target for cancer therapy.

Purpose of the Study:

• To develop a novel therapeutic strategy for lung cancer by targeting delta-5-desaturase (D5D) activity instead of directly inhibiting COX-2.
• To investigate the effects of iminodibenzyl, a D5D inhibitor, on omega-6 PUFA metabolism and cancer progression.
• To explore a new direction for lung cancer therapy using omega-6 (dihomo-γ-linolenic acid) based diets and regimens.

Main Methods:

• Utilized iminodibenzyl to inhibit delta-5-desaturase (D5D) activity, reprogramming COX-2 catalyzed omega-6 PUFA peroxidation.
• Administered dihomo-γ-linolenic acid (DGLA) supplementation in combination with iminodibenzyl.
• Assessed tumor growth and lung metastasis in mouse models (nude and C57BL/6) with COX-2 overexpression.

Main Results:

• Iminodibenzyl inhibited D5D, blocking dihomo-γ-linolenic acid (DGLA) to arachidonic acid conversion and producing 8-hydroxyoctanoic acid.
• The combination therapy suppressed the YAP1/TAZ pathway, significantly reducing tumor size and lung metastasis.
• This D5D inhibition strategy selectively damaged lung cancer cells with high COX-2 levels, sparing normal lung cells.

Conclusions:

• Inhibition of D5D offers a promising therapeutic strategy for lung cancer, distinct from direct COX-2 inhibition.
• This approach leverages COX-2 overexpression to selectively target cancer cells, minimizing harm to healthy tissues.
• The findings challenge the established COX-2 redox basis in cancer and open avenues for DGLA-based dietary interventions in lung cancer therapy.