Category: Preclinical Development
Purpose: Lung cancer is the leading cause of cancer death among both men and women. The development of lung cancer metastasis to the brain is a common lethal incidence and brain metastasis occurs in roughly 25% to 30% of patients with non-small cell lung cancer (NSCLCs). Knockdown of H2A.Z.1 (H2A histone family member Z protein) inhibits tumorigenesis in vitro by modulating cell cycle and epithelial mesenchymal transition (EMT) regulatory protein. The level of H2A.Z increased in major types of malignancies, such as breast cancer, prostate cancer, B cell lymphoma, bladder cancer, liver cancer, and lung cancer. Moreover, in genome-wide gene expression analysis of brain metastasis of clinical NSCLCs patients, H2AFZ gene (encoding the protein H2A.Z.1) is overexpressed in the brain metastasis. Thus, the hypothesis of the study is that knockdown of H2AFZ would inhibit lung cancer cell proliferation in vitro study, and overexpression of H2AFZ would be a critical target for lung cancer metastasis to the brain.
Methods: As our methods, first, we will investigate the inhibition of cell proliferation, migration, and invasion by H2AFZ knockdown stable cell (in A549 lung cancer cell) in vitro. Second, we will test whether the overexpression of H2AFZ induces brain metastasis. Third, we will exam the inhibition of tumor growth by H2AFZ knock down stable cell and brain metastasis by H2AFZ overexpression stable cell via orthotopic xenograft in mice model.
Results: In the preliminary results of this study, knockdown of H2AFZ inhibited cell proliferation in WST-1 assay and significantly changed the expression of cell cycle regulator proteins, such as cyclin D3 and p27 in western blot assay. The inhibition of cell growth also showed in knockdown group by G1 cell cycle arrest in flow cytometer. We also have found that the overexpression of H2AFZ in A549 lung cancer cells increased cell mobility and knockdown of H2AFZ inhibited cell migration in wound healing assay. In addition, we observed different level of protein expression in EMT markers both knockdown and overexpression of H2AFZ.
Conclusion: As a conclusion, knock down of H2A.Z.1 suppresses cell proliferation but the overexpression of H2A.Z.1 enhances cell proliferation and brain metastasis. Thus, H2A.Z.1 is a critical marker for inhibition of brain metastasis from non small cell lung cancer.