Expression of γ-tubulin in non-small cell lung cancer and effect on patient survival

Nicoletta F. Maounis^1,2, Eduarda Dráberová³, Nikos Trakas⁴, Maria Chorti⁵, Dimitra Riga⁶, Kimon Tzannis⁷, Meletis Kanakis⁸, Kirtanaa Voralu⁹, Eleni Ellina², Eleni Mahera⁶, Maria Demonakou⁵, Achilleas Lioulias⁸, Pavel Dráber³ and Christos D. Katsetos<sup>1,10

1</sup>Department of Pathology and Laboratory Medicine, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA, ²Department of Clinical Cytology, "Sismanoglio" General Hospital, Athens, Greece, ³Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic, ⁴Department of Clinical Biochemistry, ⁵Department of Pathology, "Sismanoglio" General Hospital, ⁶Department of Pathology, "KAT" General Hospital, ⁷Department of Clinical Therapeutics, School of Medicine, National and Kapodistrian University of Athens, ⁸Department of Cardiothoracic Surgery, "Sismanoglio" General Hospital, Athens, Greece, ⁹Department of Anesthesiology and Critical Care, Houston Methodist Hospital, Houston, TX and ¹⁰Department of Pathology and Laboratory Medicine, Drexel University College of Medicine, St. Christopher's Hospital for Children, Philadelphia, Pennsylvania, USA

Offprint requests to: Nicoletta F. Maounis, MD, PhD, MIAC, Department of Clinical Cytology, "Sismanoglio" General Hospital, 1 Sismanogliou Street, Maroussi, Athens, 15126, Greece. e-mail: nickimaounis@gmail.com

Summary. Introduction. It has been reported that overexpression and altered compartmentalization of γ-tubulin may contribute to tumorigenesis and tumor aggressiveness in a variety of human malignancies. We have shown that γ-tubulin expression and cellular distribution pattern is also altered in non-small cell lung cancer (NSCLC) (Histol. Histopathol. 2012; 27: 1183-1194). In the present study we examined the relationship between γ-tubulin expression and patient overall survival (OS). Material and methods. Immunohistochemistry was performed, with well-characterized anti-γ-tubulin antibodies, on 109 formalin-fixed, paraffin-embedded NSCLC specimens (p-TNM stage I-III). γ-Tubulin labeling indexes (LIs) were determined, and the association of γ-tubulin expression with clinicopathological parameters was evaluated. To analyze OS rates according to γ-tubulin LIs, patients were categorized into three groups: those with low (0-30%), intermediate (31-69%) or high (70-100%) γ-tubulin LI. Association of clinicopathological parameters and γ-tubulin with survival were examined using univariate and multivariate Cox regression analysis. Results. No statistically significant association was seen between γ-tubulin overexpression and histological type, tumor differentiation, p-TNM stage and adenocarcinoma subtyping. Longer survival was observed in the high γ-tubulin LI group of patients with p-TNM stages II+III when compared to intermediate or low γ-tubulin LI groups, but the difference was not statistically significant (p=0.066). On the other hand, when combined low and intermediate γ-tubulin LI groups (p-TNM stages II+III) where compared to high γ-tubulin LI group, statistically significant longer survival was observed in high γ-tubulin group (p=0.021). Conclusion. Our findings suggest that level of γ-tubulin expression may have an impact on patient survival at more advanced NSCLC stages. Histol Histopathol 34, 81-90 (2019)

Key words: Gamma-tubulin, Immunohistochemistry, Non-small cell lung cancer, Survival

DOI: 10.14670/HH-18-027