The RNA demethylase ALKBH5 promotes the progression and angiogenesis of lung cancer by regulating the stability of the LncRNA PVT1

Abstract Background N6-methyladenosine (m6A) is the most common posttranscriptional modification of RNA and plays critical roles in human cancer progression. However, the biological function of m6A methylation requires further studied in cancer, especially in tumor angiogenesis. Methods A public database was used to analyze the expression and overall survival of ALKBH5 and PVT1 in lung cancer patients. CCK-8 and colony formation assays were performed to detect cell proliferation, a transwell assay was used to assess cell migration, and a tube formation assay was performed to assess angiogenic potential in vitro. A zebrafish lung cancer xenograft model was used to verify the function of ALKBH5 and PVT1 in vivo. Western blot assays were used to measure the relative protein expression in lung cancer cells. SRAMP predictor analysis and RNA stability experiments were used to examine the potential m6A modification. Results Bioinformatics analysis showed that the expression levels of m6A-related genes were changed significantly in lung cancer tissues compared with normal lung tissues. We then identified that ALKBH5 was upregulated in lung cancer tissues and associated with poor prognosis of lung cancer patients by analyzing a public database. Knockdown of ALKBH5 inhibited the proliferation and migration of cultured lung cancer cell lines. Zebrafish lung cancer xenografts showed that ALKBH5 silencing also suppressed the growth and metastasis of lung cancer cells. Moreover, knockdown of ALKBH5 inhibited the angiogenesis of lung cancer in vitro and in vivo. Mechanistic studies showed that knockdown of ALKBH5 decreased the expression and stability of PVT1 in lung cancer cells. We next observed that PVT1 promoted the progression of lung cancer cells in vitro and in vivo and regulated the expression of VEGFA and angiogenesis in lung cancer. Finally, rescue experiments revealed that ALKBH5 regulated the proliferation, migration and angiogenesis of lung cancer cells, partially through PVT1. Conclusion Our results demonstrate that ALKBH5 promotes the progression and angiogenesis of lung cancer by regulating the expression and stability of PVT1, which provides a potential prognostic and therapeutic target for lung cancer patients.