Neutrophils expressing lysyl oxidase‐like 4 protein are present in colorectal cancer liver metastases resistant to anti‐angiogenic therapy

Abstract

Colorectal cancer liver metastases (CRCLM) that present with a replacement histopathological growth pattern (HGP) are resistant to neoadjuvant anti‐angiogenic therapy. Surrogate biomarkers are not available to preoperatively identify patients with these tumors. Here we identify differentially expressed genes between CRCLM with a replacement HGP and those with a desmoplastic HGP using RNA sequencing. We demonstrate that LOXL4 is transcriptionally upregulated in replacement HGP CRCLM compared with desmoplastic HGP CRCLM and the adjacent normal liver. Interestingly, lysyl oxidase‐like 4 (LOXL4) protein was expressed by neutrophils present in the tumor microenvironment in replacement HGP CRCLM. We further demonstrate that LOXL4 expression is higher in circulating neutrophils of cancer patients compared with healthy control patients and its expression can be induced by stimulation with lipopolysaccharide and TNF‐α. Our study is the first to show the expression of LOXL4 in neutrophils and reveals the potential for LOXL4‐expressing neutrophils to support the replacement HGP phenotype and to serve as a surrogate biomarker for this subtype of CRCLM. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Cancer cells induce hepatocytes apoptosis in co-opted colorectal cancer liver metastatic lesions

“…The histopathological growth patterns (HGPs) in CRCLM play a vital role in tumour response to anti-angiogenic therapy [6,10]. However, the factors that dictate the development of various HGPs are yet unclear, as well as the stages of their development.…”

“…Images were viewed using the Aperio ImageScope ver.11.2.0.780 software program for scoring analysis and assessment of signals. The positivity [Total number of positive pixels divided by total number of pixels: (NTotal – Nn)/(NTotal)] was assessed with an Aperio ScanScope (Aperio Technologies Inc., Vista, CA) [8–10].…”

“…Importantly, we also noticed high levels of positively stained immune cells in the replacement lesions for both cleaved caspase-3 and cleaved PRAP-1. Since higher levels of neutrophils in normal liver parenchyma have been observed in co-opted CRCLM lesions comparing to angiogenic lesions [10], we hypothesized that the apoptotic immune cells might be neutrophils. Indeed, our immunofluorescence staining confirmed that the majority of the apoptotic immune cells are neutrophils ( Figure S1).…”

“…The DHGP lesions are characterized by desmoplastic stroma separating liver parenchyma from tumour, whereas in RHGP lesions the tumour cells infiltrate through liver parenchyma and replacing the hepatocytes in a random fashion and following the sinusoidal structure [6,8]. Importantly, the cancer cells in DHGP lesions obtain blood supply through angiogenesis, while their counterparts in RHGP lesions co-opt the preexisting blood vessel to gain access to nutrients [6,[8][9][10].…”

Neutrophils: Orchestrators of the Malignant Phenotype

“…In addition, CD177 + neutrophil infiltrates in colorectal cancer patients are associated with adverse outcome in patients receiving bevacizumab [anti-vascular endothelial growth factor A (VEGF- A)] ( 74 ). Furthermore, Lysyl oxidase-like 4 (LOXL4) expressing neutrophils that infiltrated colorectal cancer liver metastases were found to identify patients that were resistant to anti-angiogenic therapy ( 75 ).…”