Progesterone receptor membrane component 2 expression leads to erlotinib resistance in lung adenocarcinoma cells

Area of Science:

• Oncology
• Molecular Biology
• Cancer Research

Background:

• Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are effective for EGFR mutation-positive non-small cell lung cancer (NSCLC).
• Acquired resistance to EGFR-TKIs, typically within a year, necessitates understanding resistance mechanisms.
• Progesterone receptor membrane component 1 (PGRMC1) has been implicated in erlotinib resistance, but PGRMC2's role is unexplored.

Purpose of the Study:

• To investigate the role of progesterone receptor membrane component 2 (PGRMC2) in acquired resistance to erlotinib in non-small cell lung cancer.
• To determine if PGRMC2 expression influences erlotinib sensitivity in resistant lung cancer cells.

Main Methods:

• Utilized an erlotinib-resistant non-small cell lung cancer cell line (PC9/ER) and its parental counterpart (PC9).
• Assessed PGRMC2 expression levels in resistant versus parental cells.
• Employed small interfering RNA (siRNA) to knockdown PGRMC2 expression in PC9/ER cells.
• Evaluated the impact of PGRMC2 knockdown on erlotinib sensitivity and p21 expression.

Main Results:

• PGRMC2 expression was significantly upregulated in erlotinib-resistant PC9/ER cells compared to PC9 cells.
• Transfection with PGRMC2 siRNA markedly enhanced the sensitivity of PC9/ER cells to erlotinib.
• Knockdown of PGRMC2 led to a reduction in the expression of p21, a known cell-cycle inhibitor.

Conclusions:

• PGRMC2 partially contributes to acquired resistance to erlotinib in non-small cell lung cancer.
• PGRMC2 may exert its effect by modulating p21 expression.
• Further investigation into PGRMC2's influence on apoptosis and cell cycle regulation is warranted.