Sonic hedgehog pathway activation is associated with cetuximab resistance and EPHB3 receptor induction in colorectal cancer.

Abstract

A major problem of colorectal cancer (CRC) targeted therapies is relapse caused by drug resistance. In most cases of CRC, patients develop resistance to anticancer drugs. Cetuximab does not show many of the side effects of other anticancer drugs and improves the survival of patients with metastatic CRC. However, the molecular mechanism of cetuximab resistance is not fully understood. Methods: EPHB3-mediated cetuximab resistance was confirmed by in vitro western blotting, colony-forming assays, WST-1 colorimetric assay, and in vivo xenograft models (n = 7 per group). RNA-seq analysis and receptor tyrosine kinase assays were performed to identify the cetuximab resistance mechanism of EPHB3. All statistical tests were two-sided. Results: The expression of EFNB3, which upregulates the EPHB3 receptor, was shown to be increased via microarray analysis. When resistance to cetuximab was acquired, EPHB3 protein levels increased. Hedgehog signaling, cancer stemness, and epithelial-mesenchymal transition signaling proteins were also increased in the cetuximab-resistant human colon cancer cell line SW48R. Despite cells acquiring resistance to cetuximab, STAT3 was still responsive to EGF and cetuximab treatment. Moreover, inhibition of EPHB3 was associated with decreased STAT3 activity. Co-immunoprecipitation confirmed that EGFR and EPHB3 bind to each other and this binding increases upon resistance acquisition, suggesting that STAT3 is activated by the binding between EGFR and EPHB3. Protein levels of GLI-1, SOX2, and Vimentin, which are affected by STAT3, also increased. Similar results were obtained in samples from patients with CRC. Conclusion: EPHB3 expression is associated with anticancer drug resistance.

• Authors: Seong Hye Park, Min Jee Jo, Bo Ram Kim, Yoon A Jeong, Yoo Jin Na, Jung Lim Kim, Soyeon Jeong, Hye Kyeong Yun, Dae Yeong Kim, Bu Gyeom Kim, Sang Hee Kang, Sang Cheul Oh, Dae-Hee Lee
• Journal: Theranostics (Theranostics) Vol. 9 Issue 8 Pg. 2235-2251 ( 2019) ISSN: 1838-7640 [Electronic] Australia
• PMID: 31149041 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents
• Gli1 protein, mouse
• Hedgehog Proteins
• SOXB1 Transcription Factors
• STAT3 Transcription Factor
• Sox2 protein, mouse
• Stat3 protein, mouse
• Vimentin
• Zinc Finger Protein GLI1
• ErbB Receptors
• Receptor, EphB3
• Cetuximab

Topics

• Animals
• Antineoplastic Agents (therapeutic use)
• Cetuximab (therapeutic use)
• Colorectal Neoplasms (drug therapy, genetics, metabolism)
• Drug Resistance, Neoplasm
• ErbB Receptors (genetics, metabolism)
• Female
• HCT116 Cells
• HT29 Cells
• Hedgehog Proteins (genetics, metabolism)
• Humans
• Mice
• Mice, Inbred BALB C
• Mice, Nude
• Receptor, EphB3 (genetics, metabolism)
• SOXB1 Transcription Factors (genetics, metabolism)
• STAT3 Transcription Factor (genetics, metabolism)
• Signal Transduction
• Vimentin (genetics, metabolism)
• Zinc Finger Protein GLI1 (genetics, metabolism)