TUBB3/{beta}III-Tubulin Regulates NSCLC Tumorigenicity

βIII-tubulin (encoded by TUBB3) expression is associated with therapeutic resistance and aggressive disease in non–small cell lung cancer (NSCLC), but the basis for its pathogenic influence is not understood. Functional and differential proteomics revealed that βIII-tubulin regulates expression of proteins associated with malignant growth and metastases. In particular, the adhesion-associated tumor suppressor maspin was differentially regulated by βIII-tubulin. Functionally, βIII-tubulin suppression altered cell morphology, reduced tumor spheroid outgrowth, and increased sensitivity to anoikis. Mechanistically, the PTEN/AKT signaling axis was defined as a critical pathway regulated by βIII-tubulin in NSCLC cells. βIII-Tubulin blockage in vivo reduced tumor incidence and growth. Overall, our findings revealed how βIII-tubulin influences tumor growth in NSCLC, defining new biologic functions and mechanism of action of βIII-tubulin in tumorigenesis. Cancer Res; 75(2); 1–11. ©2014 AACR.