title: PDL1 Regulation by p53 via miR-34.
abstract: BACKGROUND
  Although clinical studies have shown promise for targeting PD1/PDL1 signaling in non-small cell lung cancer (NSCLC), the regulation of PDL1 expression is poorly understood. Here, we show that PDL1 is regulated by p53 via miR-34.
  
  
  METHODS
  p53 wild-type and p53-deficient cell lines (p53(-/-) and p53(+/+) HCT116, p53-inducible H1299, and p53-knockdown H460) were used to determine if p53 regulates PDL1 via miR-34. PDL1 and miR-34a expression were analyzed in samples from patients with NSCLC and mutated p53 vs wild-type p53 tumors from The Cancer Genome Atlas for Lung Adenocarcinoma (TCGA LUAD). We confirmed that PDL1 is a direct target of miR-34 with western blotting and luciferase assays and used a p53(R172HΔ)g/+K-ras(LA1/+) syngeneic mouse model (n = 12) to deliver miR-34a-loaded liposomes (MRX34) plus radiotherapy (XRT) and assessed PDL1 expression and tumor-infiltrating lymphocytes (TILs). A two-sided t test was applied to compare the mean between different treatments.
  
  
  RESULTS
  We found that p53 regulates PDL1 via miR-34, which directly binds to the PDL1 3' untranslated region in models of NSCLC (fold-change luciferase activity to control group, mean for miR-34a = 0.50, SD = 0.2, P < .001; mean for miR-34b = 0.52, SD = 0.2, P = .006; and mean for miR-34c = 0.59, SD = 0.14, and P = .006). Therapeutic delivery of MRX34, currently the subject of a phase I clinical trial, promoted TILs (mean of CD8 expression percentage of control group = 22.5%, SD = 1.9%; mean of CD8 expression percentage of MRX34 = 30.1%, SD = 3.7%, P = .016, n = 4) and reduced CD8(+)PD1(+) cells in vivo (mean of CD8/PD1 expression percentage of control group = 40.2%, SD = 6.2%; mean of CD8/PD1 expression percentage of MRX34 = 20.3%, SD = 5.1%, P = .001, n = 4). Further, MRX34 plus XRT increased CD8(+) cell numbers more than either therapy alone (mean of CD8 expression percentage of MRX34 plus XRT to control group = 44.2%, SD = 8.7%, P = .004, n = 4). Finally, miR-34a delivery reduced the numbers of radiation-induced macrophages (mean of F4-80 expression percentage of control group = 52.4%, SD = 1.7%; mean of F4-80 expression percentage of MRX34 = 40.1%, SD = 3.5%, P = .008, n = 4) and T-regulatory cells.
  
  
  CONCLUSIONS
  We identified a novel mechanism by which tumor immune evasion is regulated by p53/miR-34/PDL1 axis. Our results suggest that delivery of miRNAs with standard therapies, such as XRT, may represent a novel therapeutic approach for lung cancer.
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: Maria Angelica
authors.initials: MA
authors.lastname: Cortez
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: Cristina
authors.initials: C
authors.lastname: Ivan
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: David
authors.initials: D
authors.lastname: Valdecanas
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: Heidi J
authors.initials: HJ
authors.lastname: Peltier
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: Yuping
authors.initials: Y
authors.lastname: Ye
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: Luiz
authors.initials: L
authors.lastname: Araujo
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: David P
authors.initials: DP
authors.lastname: Carbone
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: Konstantin
authors.initials: K
authors.lastname: Shilo
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: Dipak K
authors.initials: DK
authors.lastname: Giri
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: Kevin
authors.initials: K
authors.lastname: Kelnar
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: Desiree
authors.initials: D
authors.lastname: Martin
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Komaki
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Gomez
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: Sunil
authors.initials: S
authors.lastname: Krishnan
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: George A
authors.initials: GA
authors.lastname: Calin
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG).
authors.forename: Andreas G
authors.initials: AG
authors.lastname: Bader
authors.affiliation: Departments of Experimental Radiation Oncology (MAC, DV, XW, YY), Experimental Therapeutics (CI, GAC), and Radiation Oncology (RK, DRG, SK, JWW), The University of Texas MD Anderson Cancer Center, Houston, TX; Mirna Therapeutics, Inc., Austin, TX (HJP, KK, DM, AGB); Ohio State University, Columbus, OH (LA, DPC, KS); Texas Veterinary Pathology Associates (Houston), Houston, TX (DKG). jwelsh@mdanderson.org.
authors.forename: James W
authors.initials: JW
authors.lastname: Welsh
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism; D000077192:Adenocarcinoma of Lung; D000818:Animals; D060890:B7-H1 Antigen / Q000378:metabolism*; D016827:CD8 Antigens / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000378:metabolism* / Q000532:radiotherapy; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000528:radiation effects; D008081:Liposomes; D008175:Lung Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000532:radiotherapy; D051379:Mice; D035683:MicroRNAs / Q000008:administration & dosage / Q000378:metabolism*; D009374:Neoplasms, Experimental / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D060890:B7-H1 Antigen; C423236:CD274 protein, human; D016827:CD8 Antigens; D008081:Liposomes; C551848:MIRN34a microRNA, mouse; D035683:MicroRNAs; D016159:Tumor Suppressor Protein p53