67: Molecular mechanism of colorectal peritoneal metastasis: an interesting TWIST

Saturday, March 25, 2023

8:01 AM – 8:11 AM

Location: Ballroom B

Abstract Presenter(s)

Manoj H. Palavalli, MD (he/him/his)

Research Assistant
The Ohio State University Wexner Medical Center, The James Cancer Hospital and Solove Research Institute
Columbus, Ohio, United States

Disclosure(s): No financial relationships to disclose

First Author(s)

Manoj H. Palavalli, MD (he/him/his)

Research Assistant
The Ohio State University Wexner Medical Center, The James Cancer Hospital and Solove Research Institute
Columbus, Ohio, United States

Disclosure(s): No financial relationships to disclose

Author(s)

MI

Mozaffarul Islam, PhD

Research Scientist
The Ohio State University Wexner Medical Center, The James Cancer Hospital and Solove Research Institute, United States

Disclosure information not submitted.
Christopher T. Aquina, MD, MPH

Assistant Professor
AdventHealth Orlando
Orlando, Florida, United States

Disclosure information not submitted.
SR

Samantha Ruff, MD

Fellow
The Ohio State University Wexner Medical Center, The James Cancer Hospital and Solove Research Institute, United States

Disclosure information not submitted.
GK

Gyulnara Kasumova, MD

GCSO Fellow
Ohio State University/ James Cancer Hospital, United States

Disclosure information not submitted.
AK

Andrew Koempel, n/a

Undergraduate Research Assistant
The Ohio State University Wexner Medical Center, The James Cancer Hospital and Solove Research Institute, United States

Disclosure information not submitted.
JW

Jing Wen, MS

Research Assistant
The Ohio State University Wexner Medical Center, The James Cancer Hospital and Solove Research Institute, United States

Disclosure information not submitted.
Oliver S. Eng, MD (he/him/his)

Associate Professor of Surgery
University of California, Irvine, United States

Disclosure(s): Tempus Labs, Inc.: Speaker (Ongoing)
MA

Mohamed Adam, MD

Assistant Professor of Surgery
University of California - San Francisco Medical Center, United States

Disclosure information not submitted.
Jordan M. Cloyd, MD

Assistant Professor
The Ohio State University
Columbus, OH, United States

Disclosure information not submitted.
Aslam Ejaz, MD, MPH

Assistant Professor of Surgery
The Ohio State University

Disclosure information not submitted.
Joal D. Beane, MD

Assistant Professor
The Ohio State University Wexner Medical Center- Division of Surgical Oncology
Columbus, Ohio, United States

Disclosure information not submitted.
Alex C. Kim, MD, PhD

Assistant Professor of Surgery
The Ohio State University Wexner Medical Center, The James Cancer Hospital and Solove Research Institute
Columbus, Ohio, United States

Disclosure information not submitted.

Disclosure(s):

Manoj H. Palavalli, MD: No financial relationships to disclose

Oliver S. Eng, MD: Tempus Labs, Inc.: Speaker (Ongoing)

Introduction: Colorectal cancer (CRC) carries a high propensity for peritoneal metastasis (PM). The diagnosis of CRC PM results in median overall survival of 16.3 months in treated patients with nearly 0% surviving at 5 years. These devastating outcomes are due to treatment resistance, deficiency in effective therapeutic options, and lack of understanding for CRC PM progression. As such, there is an immense therapeutic implication to define the genetic and molecular drivers responsible for CRC PM. A process known as the epithelial-mesenchymal transition (EMT) is thought to be the biologic programing responsible for cancer metastasis and is activated by transcription factors (TF). Despite the importance of EMT in cancer metastasis, analysis of EMT in setting of CRC PM remains deficient. This study sought to examine the expression profile of canonical EMT-TFs and investigate its role in CRC PM.

Methods: Patient derived tumor specimens were prospectively collected under the approved protocol by our IRB. Established human and mouse cell lines were obtained through ATCC. Protein and RNA lysates were generated per standard protocol. Immunoblotting assay and RT-PCR were performed to assess the expression profile of EMT-TF and downstream targets including TWIST1/2, SNAI1/2, ZEB1/2, CDH1, CDH2, VIM, and ACTB. TWIST1 transcript was knocked down using lentiviral shRNA system. Pharmacologic inhibition of TWIST1 was performed using harmine. Invasion and colony formation assays were performed per standard protocol.

Results: Examination of various human and mouse cell lines for EMT-TF protein expression revealed variable expression of TWIST1, SNA1/2, and ZEB1. Analysis of patient derived CRC PM specimens from the operating room demonstrated exclusive TWIST1 expression. To understand the functional role of TWIST1, we performed both shRNA knockdown and pharmacologic inhibition in known TWIST1 expressing CRC cell lines. shRNA knockdown resulted in reversion of mesenchymal phenotype in TWIST1 expressing CRC cell line, LoVo. Pharmacologic inhibition of TWIST1 exhibited concentration dependent cytotoxicity in cell lines. Moreover, functional assessment of TWIST1 inhibition in cell lines demonstrated decrease in Matrigel invasion and colony formation.

Conclusions: TWIST1 appears to be a specific EMT-TF for CRC PM. It is responsible for molecular EMT phenotype in CRC PM with variable expression of CDH1, CDH2, and VIM. Pharmacologic and shRNA inhibition of TWIST1 further confirmed its role in the development of CRC PM. TWIST1 may serve as an ideal therapeutic target for CRC PM.

Learning Objectives:

Upon completion, participant will be able to understand the role of TWIST1 in colorectal cancer peritoneal metastasis.
Upon completion, participant will be able to describe the importance of epithelial to mesenchymal transition in cancer metastasis.
Upon completion, participant will be able to define a potential novel therapeutic target in management of colorectal cancer peritoneal metastasis.