The expression patterns and prognostic significance of pleckstrin homology-like domain family A (PHLDA) in lung cancer and malignant mesothelioma

• Published in: Journal of thoracic disease Vol. 13; no. 2; pp. 689 - 707
• Main Authors: Baldavira, Camila M, Machado-Rugolo, Juliana, Prieto, Tabatha G, Bastos, Daniel R, Balancin, Marcelo, Ab'Saber, Alexandre M, Yaegashi, Lygia B, Souza, Paola C, Farhat, Cecilia, Takagaki, Teresa Y, Nagai, Maria Ap, Capelozzi, Vera L
• Format: Journal Article
• Language: English
• Published: China AME Publishing Company 01.02.2021
• Subjects: Original; Morphometry; malignant mesothelioma; pleckstrin homology-like domain family A (PHLDA); data mining; lung adenocarcinoma
• ISSN: 2072-1439; 2077-6624
• DOI: 10.21037/jtd-20-2909

Pleckstrin homology domain family A (PHLDA) genes play important roles in cancer cellular processes, including inhibiting Akt activation, repressing growth factor signaling, inhibiting the negative feedback of EGFR/ErbB2 signaling cells, and inducing apoptosis. However, the prognostic significance of PHLDA in non-small cell lung cancer (NSCLC) and malignant pleural mesothelioma (MM) remains unclear. The present study investigates the associations between PHLDA expression patterns and their prognostic value in lung adenocarcinoma (LUAD) and MM. We analyzed PHLDA family members at the genomic level to explore their mRNA expression pattern and predictive significance in LUAD and MM. We then created a PHLDA-drug interaction network and a protein-protein interaction (PPI) network using different databases. Finally, we immunohistochemically assessed the protein expression of each PHLDA family member on tissue microarrays (TMAs) in both LUAD and MM cohorts with long-term follow-up. While mRNA expression in both LUAD and MM was lower than that of normal tissue, mRNA was significantly overexpressed in LUAD, and mRNA was overexpressed in MM. In NSCLC, both low mRNA expression and high mRNA expression correlated with worse overall survival (OS) (P<0.01), whereas high mRNA expression was associated with better OS (P<0.01). In MM, patients presenting high and mRNA expression had poor OS (P=0.01 and P<0.01, respectively). In addition, the PHLDA-drug interaction network indicated that several common drugs could potentially modulate PHLDA expression, and the PPI network suggested that interacts with Notch family members, whereas interacts with TP53. Our results also showed that the expression of PHLDA2 and PHLDA3 was significantly higher in LUAD and MM than that of PHLDA1 (P<0.05) and was associated with the risk of death. While patients with PHLDA2 >85.09 cells/mm had a low risk of death (P=0.01) and a median survival time of 48 months, those with PHLDA3 <70.38 cells/mm had a high risk of death (P=0.03) and a median survival time of 34 months. We shed light on the role of the PHLDA family as promising predictive biomarkers and potential therapeutic targets in LUAD and MM.