Targeting the E3 Ubiquitin Ligase PJA1 Enhances Tumor-Suppressing TGFβ Signaling

Jian Chen; Abhisek Mitra; Shulin Li; Shumei Song; Bao-Ngoc Nguyen; Jiun-Sheng Chen; Ji-Hyun Shin; Nancy R Gough; Paul Lin; Vincent Obias; Aiwu Ruth He; Zhixing Yao; Tathiane M Malta; Houtan Noushmehr; Patricia S Latham; Xiaoping Su; Asif Rashid; Bibhuti Mishra; Ray-Chang Wu; Lopa Mishra

doi:10.1158/0008-5472.CAN-19-3116

Targeting the E3 Ubiquitin Ligase PJA1 Enhances Tumor-Suppressing TGFβ Signaling

Cancer Res. 2020 May 1;80(9):1819-1832. doi: 10.1158/0008-5472.CAN-19-3116. Epub 2020 Mar 3.

Authors

Jian Chen¹, Abhisek Mitra², Shulin Li³, Shumei Song⁴, Bao-Ngoc Nguyen⁵, Jiun-Sheng Chen⁶, Ji-Hyun Shin⁶, Nancy R Gough^{5

7}, Paul Lin⁸, Vincent Obias⁸, Aiwu Ruth He⁹, Zhixing Yao¹⁰, Tathiane M Malta¹¹, Houtan Noushmehr¹¹, Patricia S Latham¹², Xiaoping Su¹³, Asif Rashid¹⁴, Bibhuti Mishra⁵, Ray-Chang Wu¹⁵, Lopa Mishra^{16

17}

Affiliations

¹ Department of Gastroenterology, Hepatology, and Nutrition, The University of Texas MD Anderson Cancer Center, Houston, Texas. lmishra@gwu.edu jianchen@mdanderson.org.
² Pfizer Inc. Integrative Biotechnology Group, Pearl River, New York.
³ Department of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas.
⁴ Department of GI Medical Oncology-Research, The University of Texas MD Anderson Cancer Center, Houston, Texas.
⁵ Center for Translational Medicine, Department of Surgery, George Washington University, Washington, D.C.
⁶ Department of Gastroenterology, Hepatology, and Nutrition, The University of Texas MD Anderson Cancer Center, Houston, Texas.
⁷ BioSerendipity, LLC, Elkridge, Maryland.
⁸ Department of Surgery, George Washington University, Washington, D.C.
⁹ Department of Medicine and Oncology, Georgetown University, Lombardi Comprehensive Cancer Center Washington, D.C.
¹⁰ Department of Biochemistry and Molecular Biology, Howard University, Washington, D.C.
¹¹ Department of Neurosurgery, Henry Ford Hospital, Detroit, Michigan.
¹² Department of Pathology, George Washington University, Washington, D.C.
¹³ Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
¹⁴ Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
¹⁵ Department of Biochemistry & Molecular Biology, George Washington University, Washington, D.C.
¹⁶ Center for Translational Medicine, Department of Surgery, George Washington University, Washington, D.C. lmishra@gwu.edu jianchen@mdanderson.org.
¹⁷ Gastroenterology, Hepatology, and Nutrition Section, VA Medical Center, Washington, D.C.

Abstract

RING-finger E3 ligases are instrumental in the regulation of inflammatory cascades, apoptosis, and cancer. However, their roles are relatively unknown in TGFβ/SMAD signaling. SMAD3 and its adaptors, such as β2SP, are important mediators of TGFβ signaling and regulate gene expression to suppress stem cell-like phenotypes in diverse cancers, including hepatocellular carcinoma (HCC). Here, PJA1, an E3 ligase, promoted ubiquitination and degradation of phosphorylated SMAD3 and impaired a SMAD3/β2SP-dependent tumor-suppressing pathway in multiple HCC cell lines. In mice deficient for SMAD3 (Smad3 ^+/-), PJA1 overexpression promoted the transformation of liver stem cells. Analysis of genes regulated by PJA1 knockdown and TGFβ1 signaling revealed 1,584 co-upregulated genes and 1,280 co-downregulated genes, including many implicated in cancer. The E3 ligase inhibitor RTA405 enhanced SMAD3-regulated gene expression and reduced growth of HCC cells in culture and xenografts of HCC tumors, suggesting that inhibition of PJA1 may be beneficial in treating HCC or preventing HCC development in at-risk patients.Significance: These findings provide a novel mechanism regulating the tumor suppressor function of TGFβ in liver carcinogenesis.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Animals
Carcinoma, Hepatocellular / genetics
Carcinoma, Hepatocellular / metabolism*
Carcinoma, Hepatocellular / pathology
Cell Line, Tumor
Cell Proliferation / drug effects
Cell Transformation, Neoplastic / metabolism
Cell Transformation, Neoplastic / pathology
Down-Regulation
Exome Sequencing
Gene Deletion
Gene Expression Regulation
Gene Knockdown Techniques
Gene Silencing
Heterografts
Humans
Liver Neoplasms / genetics
Liver Neoplasms / metabolism*
Liver Neoplasms / pathology
Mice
Mice, Nude
Neoplastic Stem Cells
Oleanolic Acid / analogs & derivatives
Oleanolic Acid / pharmacology
Phosphorylation
RNA, Small Interfering
Smad Proteins / metabolism
Smad2 Protein / metabolism
Smad3 Protein / deficiency
Smad3 Protein / genetics
Smad3 Protein / metabolism*
Spectrin / genetics
Spectrin / metabolism
Stem Cells / pathology
Transforming Growth Factor beta / genetics
Transforming Growth Factor beta / metabolism*
Transforming Growth Factor beta1 / metabolism
Ubiquitin-Protein Ligases / antagonists & inhibitors
Ubiquitin-Protein Ligases / genetics
Ubiquitin-Protein Ligases / metabolism*
Ubiquitination
Up-Regulation

Substances

2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid ethyl amide
RNA, Small Interfering
SMAD3 protein, human
SPTBN1 protein, human
Smad Proteins
Smad2 Protein
Smad2 protein, mouse
Smad3 Protein
TGFB1 protein, human
Transforming Growth Factor beta
Transforming Growth Factor beta1
Spectrin
Oleanolic Acid
PJA1 protein, human
Pja1 protein, mouse
Ubiquitin-Protein Ligases

Abstract

Publication types

MeSH terms

Substances

Grants and funding