Lupeol evokes anticancer effects in oral squamous cell carcinoma by inhibiting oncogenic EGFR pathway Sanchita Rauth 1 • Sudipta Ray 1 • Sayantan Bhattacharyya 1 • Debapriya Ghosh Mehrotra 2 • Neyaz Alam 3 • Goutam Mondal 4 • Partha Nath 5 • Asoke Roy 6 • Jaydip Biswas 7 • Nabendu Murmu 1 Received: 15 December 2015 / Accepted: 13 May 2016 Ó Springer Science+Business Media New York 2016 Abstract Epidermal growth factor receptor (EGFR) path- way is overexpressed in head and neck cancer (HNC). Lupeol, a natural triterpene (phytosterol found in fruits, vegetables, etc.), has been reported to be effective against multiple cancer indications. Here we investigate the anti- tumor effects of Lupeol and underlying mechanism in oral cancer. Lupeol-induced antitumor response was evaluated in two oral squamous cell carcinoma (OSCC) cell lines (UPCI:SCC131 and UPCI:SCC084) by viability (MTT), proliferation, and colony formation assays. Lupeol-medi- ated induction of apoptosis was examined by caspase 3/7 assay and flow cytometry. Effect of Lupeol on EGFR in the presence or absence of EGF was delineated by Western blot. The mRNA stability assay was performed to check the role of Lupeol on COX-2 mRNA regulation. Lupeol inhibited proliferation of OSCC cells in vitro by inducing apoptosis 48 h post treatment. Ligand-induced phospho- rylation of EGFR and subsequent activation of its down- stream molecules such as protein kinase B (PKB or AKT), I kappa B (IjB), and nuclear factor kappa B (NF-jB) was also found to be, in part, suppressed. Interestingly, Lupeol suppressed expression of COX-2 at mRNA and protein level in a time-dependent manner. Primary explants from oral squamous cell carcinoma tissues further confirmed significant inhibition of proliferation (Ki67) in Lupeol- treated explants as compared to untreated control at 48 h. Together these data suggest that Lupeol may act as a potent inhibitor of the EGFR signaling in OSCC and therefore imply its role in triggering antitumor efficacy. Keywords Oral squamous cell carcinoma Á Lupeol Á EGFR Á COX-2 Introduction Oral squamous cell carcinoma (OSCC) is the sixth most common cancer in the world, accounting for 50–70 % of total cancer-related mortality [1, 2]. Many types of cancers including head and neck squamous cell carcinoma (HNSCC) show perturbation of the epidermal growth fac- tor receptor (EGFR) which is generally associated with poor prognosis, invasion, and metastasis; thus, multiple drug targets have been developed against EGFR [3–7]. EGFR can bind to a variety of ligands such as Epidermal Growth Factor (EGF), Transforming Growth Factor-a (TGF-a), and Amphiregulin [8, 9]. EGFR stimulation leads & Nabendu Murmu nabendu.murmu@cnci.org.in 1 Department of Signal Transduction and Biogenic Amines, Chittaranjan National Cancer Institute, 37 - S.P Mukherjee Road, Kolkata 700026, India 2 Department of Molecular Pathology, Mitra Biotech, Narayana Nethralaya, Narayana Health City, Hosur Main Road, Bangalore 560099, India 3 Department of Surgical Oncology, Chittaranjan National Cancer Institute, 37 - S.P Mukherjee Road, Kolkata 700026, India 4 Department of Pathology, Chittaranjan National Cancer Institute, 37 - S.P Mukherjee Road, Kolkata 700026, India 5 Department of Medical Oncology, Chittaranjan National Cancer Institute, 37 - S.P Mukherjee Road, Kolkata 700026, India 6 Department of Pathology & Cancer Screening, Chittaranjan National Cancer Institute, 37 - S.P Mukherjee Road, Kolkata 700026, India 7 Department of Translation Research, Chittaranjan National Cancer Institute, 37 - S.P Mukherjee Road, Kolkata 700026, India 123 Mol Cell Biochem DOI 10.1007/s11010-016-2717-y