Modification of cysteine 457 in plakoglobin modulates the proliferation and migration of colorectal cancer cells by altering binding to E-cadherin/catenins

ABSTRACT

Objectives: In tissue samples from patients with colorectal cancer (CRC), oxidation of C420 and C457 of plakoglobin (Pg) within tumor tissue was identified by proteomic analysis. The aim of this study was to identify the roles of Pg C420 and C457.

Methods: Human CRC tissues, CRC and breast cancer cells, and normal mouse colon were prepared to validate Pg oxidation. MC38 cells were co-transfected with E-cadherin plus wild type (WT) or mutant (C420S or C457S) Pg to evaluate protein interactions and cellular localization, proliferation, and migration.

Results: Pg was more oxidized in stage III CRC tumor tissue than in non-tumor tissue. Similar oxidation of Pg was elicited by H₂O₂ treatment in normal colon and cancer cells. C457S Pg exhibited diminished binding to E-cadherin and α-catenin, and reduced the assembly of E-cadherin–α-/β-catenin complexes. Correspondingly, immunofluorescent analysis of Pg cellular localization suggested impaired binding of C457S Pg to membranes. Cell migration and proliferation were also suppressed in C457S-expressing cells.

Discussion: Pg appears to be redox-sensitive in cancer, and the C457 modification may impair cell migration and proliferation by affecting its interaction with the E-cadherin/catenin axis. Our findings suggest that redox-sensitive cysteines of Pg may be the targets for CRC therapy.

KEYWORDS:

• Colorectal cancer
• cysteine
• E-cadherin
• oxidation
• plakoglobin

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Dr Suhee Kim is a research professor of the Department of Biochemistry at School of Dentistry in Chonnam National University. She graduated with BS/MS degree in College of Veterinary Medicine from Chonbuk National University and received her PhD in College of Veterinary Medicine from Chonbuk National University in 2009. During her PhD course, she studied on functional damages of sperm after cryopreservation and improvement of cryopreserved sperm quality in dogs. Following her graduate studies, she worked as a postdoctoral researcher from December 2010 to November 2012 at Department of Veterinary Pathobiology, University of Missouri-Columbia, studying rat sperm cryobiology. Recently, she joined Prof. Lee, Tae-Hoon's lab in Chonnam National University and is studying on ROS and defense mechanisms using animal disease model.

Dr Sun Hee Ahn is a research professor of the Department of Biochemistry at School of Dentistry in Chonnam National University. She graduated with BS/MS degree in Biotechnology and Bioengineering from Pukyong National University. She received her PhD in Microbial Engineering from Pukyong National University in 2006. While earning her PhD, she studied various virulence factors such as (metalloprotease, phospholipase, hemolysin, phosphomannomutase (PMM), and flagella motor protein (MotX)), using knock-out mutations and animal models. Through these studies, she developed a keen insight into the molecular mechanism of bacterial pathogenesis. Following her graduate studies, she worked as a postdoctoral researcher from September 2006 to May 2008 at Case Western Reserve University studying receptor proteins in oral epithelial cells which interact with adhesin proteins of Fusobacterium nucleatum. This further sparked her interest in researching the host-pathogen interaction, and brought her to Duke. During her time at Duke (2008–2012), Dr. Ahn has produced a number of interesting results while studying murine host susceptibility to S. aureus by microarray and QTL analyses. She published these results in the peer-reviewed journal. She was also Principal Investigator on a competitive grant from Pfizer Inc. Recently, she joined Prof. Lee, Tae-Hoon's lab in Chonnam National University and is studying Host Redox Signaling in bacterial infectious disease model.

Hee-Young Yang received MS/PhD degree in Chonnam National University. Now she is working in the Daegu Gyeongbuk Medical Innovation Foundation (DFMIF) as researcher.

Jin-Sil Lee is a student in the master's course of School of Dentistry at Chonnam National University.

Hyang-Gi Choi is a student in the master's course of School of Dentistry at Chonnam National University.

Dr Young-Kyu Park is a professor of division of gastrointestinal surgery, department of surgery at Chonnam National University Hwasun Hospital. He received MD/PhD in Chonnam National University Medical School. He studied on development of GI tract cancer at Vanderbilt University in USA during postdoctoral course. Now he is working in the translational research field of stomach and colon cancer and also many clinical researches as surgical oncologist.

Tae-Hoon Lee is a professor of Biochemistry, School of Densitry at Chonnam National University. He is a Biochemist in Dental Science. Scientific Interest: Redox regulation in protein. Experimental Models: Disease model mice as osteoporosis, bone defect and cancer.

ORCiD

Suhee Kim http://orcid.org/0000-0002-9315-0360

Sun Hee Ahn http://orcid.org/0000-0002-0772-9588

Hee-Young Yang http://orcid.org/0000-0001-7654-8708

Jin-Sil Lee http://orcid.org/0000-0002-9795-3128

Hyang-Gi Choi http://orcid.org/0000-0001-7487-4585

Young-Kyu Park http://orcid.org/0000-0002-3009-404X

Tae-Hoon Lee http://orcid.org/0000-0003-0105-1750

Additional information

Funding

This work was supported by Korea Mouse Phenotyping Project (NRF-2014M3A9D5073721) of the Ministry of Science, ICT and Future Planning through the National Research Foundation and by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIP) (2011-0030121).