Qing-Ming Wang1, Guang-Yu Lian2, Yuan Song3, Yan-Fang Huang3, Yi Gong4. 1. Department of Hematology, The Second Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, PR China. Electronic address: wdfrt711@163.com. 2. Department of Medicine & Therapeutics, The Chinese University of Hong Kong, Hong Kong, China. 3. Department of Hematology, The Second Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, PR China. 4. Department of Obstetrics and Gynaecology, The First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, PR China. Electronic address: gongyi5431@163.com.
Abstract
BACKGROUND: PD-L1 enhanced the tumorigenesis and immune escape abilities of cancers. The upstream mechanisms of PD-L1 in regulating tumorigenesis and immune escape of diffuse large B cell lymphoma (DLBCL) remained unclear. METHODS: Human DLBCL cell line OCI-Ly10 and DLBCL patient samples were used in this study. MALAT1 was knocked down by shRNA. MiR-195 was inhibited by miR-195 inhibitor. Levels of MALAT1, PD-L1, miR-195 and CD8 were detected by RT-qPCR. Protein levels of PD-L1, Ras, p-ERK1/2, ERK1/2, Slug, E-cadherin, N-cadherin, Vimentin were detected by western blotting. The interaction between MALAT1 and miR-195, miR-195 and PD-L1 were detected by luciferase assay. OCI-Ly10 cell proliferation and apoptosis were detected by MTT and Annexin V/PI assays, respectively. Migration was detected by transwell assay. Cytotoxicity of CD8+ T cells was detected by LDH cytotoxicity kit. Proliferation and apoptosis of CD8+ T cell co-cultured with OCI-Ly10 cells were analyzed by CFSE and Annexin V/PI staining. RESULTS: MALAT1, PD-L1 and CD8 were up-regulated in DLBCL tissues while miR-195 was down-regulated. MiR-195 was negatively correlated with MALAT1 and PD-L1. MALAT1 could sponge miR-195 to regulate the expression of PD-L1. shMALAT1 treatment increased miR-195 level and decreased PD-L1 level. It also inhibited cell proliferation, migration and immune escape ability while increased apoptosis ratio of OCI-Ly10 cells. shMALAT1 treatment in OCI-Ly10 cells also promoted proliferation and inhibited apoptosis of CD8+ T cells. Knocking down of MALAT1 also suppressed EMT-like process via Ras/ERK signaling pathway. These effects were all rescued by miR-195 inhibitor. CONCLUSION: Long non-coding RNA MALAT1 sponged miR-195 to regulate proliferation, apoptosis and migration and immune escape abilities of DLBCL by regulation of PD-L1.
BACKGROUND:PD-L1 enhanced the tumorigenesis and immune escape abilities of cancers. The upstream mechanisms of PD-L1 in regulating tumorigenesis and immune escape of diffuse large B cell lymphoma (DLBCL) remained unclear. METHODS:Human DLBCL cell line OCI-Ly10 and DLBCL patient samples were used in this study. MALAT1 was knocked down by shRNA. MiR-195 was inhibited by miR-195 inhibitor. Levels of MALAT1, PD-L1, miR-195 and CD8 were detected by RT-qPCR. Protein levels of PD-L1, Ras, p-ERK1/2, ERK1/2, Slug, E-cadherin, N-cadherin, Vimentin were detected by western blotting. The interaction between MALAT1 and miR-195, miR-195 and PD-L1 were detected by luciferase assay. OCI-Ly10 cell proliferation and apoptosis were detected by MTT and Annexin V/PI assays, respectively. Migration was detected by transwell assay. Cytotoxicity of CD8+ T cells was detected by LDH cytotoxicity kit. Proliferation and apoptosis of CD8+ T cell co-cultured with OCI-Ly10 cells were analyzed by CFSE and Annexin V/PI staining. RESULTS:MALAT1, PD-L1 and CD8 were up-regulated in DLBCL tissues while miR-195 was down-regulated. MiR-195 was negatively correlated with MALAT1 and PD-L1. MALAT1 could sponge miR-195 to regulate the expression of PD-L1. shMALAT1 treatment increased miR-195 level and decreased PD-L1 level. It also inhibited cell proliferation, migration and immune escape ability while increased apoptosis ratio of OCI-Ly10 cells. shMALAT1 treatment in OCI-Ly10 cells also promoted proliferation and inhibited apoptosis of CD8+ T cells. Knocking down of MALAT1 also suppressed EMT-like process via Ras/ERK signaling pathway. These effects were all rescued by miR-195 inhibitor. CONCLUSION: Long non-coding RNA MALAT1 sponged miR-195 to regulate proliferation, apoptosis and migration and immune escape abilities of DLBCL by regulation of PD-L1.