RNA Demethylase ALKBH5 Promotes Progression and Angiogenesis of Lung Cancer via Regulating the Stability of LncRNA PVT1

Abstract Background N6-methyladenosine (m6A) is the most common posttranscriptional modification of RNA and plays critical roles in human cancer progression. However, biological function of the m6A methylation needs to be further studied in cancer, especially on tumor angiogenesis. Methods The public database were 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 the cell proliferation, transwell assay was used to assess the cell migration, and tube formation assay was performed to assess the angiogenic potential in vitro. The zebrafish lung cancer xenograft model was used to verify the function of ALKBH5 and PVT1 in vivo. Western-blot assay was used to measure the expression of relative protein in lung cancer cells. SRAMP predictor analysis and RNA stability experiments were used to examine the potential m6A modification. Results Bioinformatics analysis showed the expression levels of m6A-related genes were changed significantly in lung cancer tissues comparing 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 the public database. Knockdown of ALKBH5 inhibited the proliferation and migration of cultured lung cancer cell lines. Zebrafish lung cancer xenografts also showed ALKBH5 silence suppressed the growth and metastasis of lung cancer cells. Moreover, knockdown of ALKBH5 inhibited the angiogenesis of lung cancer in vitro and in vivo. Mechanism studies showed that knockdown of ALKBH5 decreased the expression and stability of PVT1 in lung cancer cells. We next verified that PVT1 promoted the progression of lung cancer cells in vitro and in vivo, and it also regulated the expression of VEGFA and angiogenesis of 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 ALKBH5 promotes the progression and angiogenesis of lung cancer via regulating the expression and stability of PVT1, which provides the potential prognostic and therapeutic target for lung cancer patients.