Hinokitiol Induces DNA Damage and Autophagy followed by Cell Cycle Arrest and Senescence in Gefitinib-Resistant Lung Adenocarcinoma Cells

Abstract

Despite good initial responses, drug resistance and disease recurrence remain major issues for lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) mutations taking EGFR-tyrosine kinase inhibitors (TKI). To discover new strategies to overcome this issue, we investigated 40 essential oils from plants indigenous to Taiwan as alternative treatments for a wide range of illnesses. Here, we found that hinokitiol, a natural monoterpenoid from the heartwood of Calocedrus formosana, exhibited potent anticancer effects. In this study, we demonstrated that hinokitiol inhibited the proliferation and colony formation ability of lung adenocarcinoma cells as well as the EGFR-TKI-resistant lines PC9-IR and H1975. Transcriptomic analysis and pathway prediction algorithms indicated that the main implicated pathways included DNA damage, autophagy, and cell cycle. Further investigations confirmed that in lung cancer cells, hinokitiol inhibited cell proliferation by inducing the p53-independent DNA damage response, autophagy (not apoptosis), S-phase cell cycle arrest, and senescence. Furthermore, hinokitiol inhibited the growth of xenograft tumors in association with DNA damage and autophagy but exhibited fewer effects on lung stromal fibroblasts. In summary, we demonstrated novel mechanisms by which hinokitiol, an essential oil extract, acted as a promising anticancer agent to overcome EGFR-TKI resistance in lung cancer cells via inducing DNA damage, autophagy, cell cycle arrest, and senescence in vitro and in vivo.

Genome-wide profiling of long non-coding RNA expression patterns in the EGFR-TKI resistance of lung adenocarcinoma by microarray

“…The most widely used technique for function prediction is the ̔guilt by association̓ method, which aims to interrogate the co-expressed protein-coding genes and relevant bio-pathways (13). Among the hundreds of pathways as-predicted, some are key pathways in the mechanisms of gefitinib resistance, such as focal adhesion, cell proliferation, cell cycle and apoptosis (16)(17)(18). We compared the differentially expressed mRNAs with other studies, and the high consistency strongly supported our predictions.…”

“…The lncRNAs were clustered into hundreds of GO and KEGG pathway annotations. Certain pathways are known to be involved in the mechanism of gefitinib resistance, including focal adhesion, cell cycle, cell proliferation and apoptosis (16)(17)(18). For example, 186 lncRNAs were clustered into apoptosis and 79 in the focal adhesion.…”

The beneficial role of anti-inflammatory dietary ingredients in attenuating markers of chronic low-grade inflammation in aging

“…In the same report, prospective epidemiologic studies did not provide robust evidence for a protective effect of green tea consumption on breast cancer development. While the role of botanical extracts with anti-inflammatory properties in reducing the risks of cancer in aging merits further investigation, the beneficial effects of such extracts might also be due their non-inflammatory effects including effects on telomerase activity [64], induction of p53, tumor suppressor protein [65], and induction of DNA damage and autophagy [66].…”

Epigenetics and miRNA as predictive markers and targets for lung cancer chemotherapy

“…In NSCLC, the drug resistance is frequently inherent, whereas SCLC acquires resistance with continued drug administration. 6 The mechanisms of lung cancer resistance to anticancer agents include increased drug efflux by ATP binding cassette superfamily, drug inactivation and/or sequestration by enzymes, increased DNA repair activity, apoptosis defects, and alteration of drug target. 2 The genetic basis of these mechanisms has been intensively studied whereas a link between these mechanisms and epigenetic profile of cancer cells is still lacking.…”