Investigating Ras homolog gene family member C (RhoC) and Ki67 expression following external beam radiation therapy show increased RhoC expression in relapsing prostate cancer xenografts

Amanda Kristiansson; Crister Ceberg; Anders Bjartell; Jens Ceder; Oskar Vilhelmsson Timmermand

doi:10.1016/j.bbrc.2024.150324

Investigating Ras homolog gene family member C (RhoC) and Ki67 expression following external beam radiation therapy show increased RhoC expression in relapsing prostate cancer xenografts

Biochem Biophys Res Commun. 2024 Oct 8:728:150324. doi: 10.1016/j.bbrc.2024.150324. Epub 2024 Jun 28.

Authors

Amanda Kristiansson¹, Crister Ceberg², Anders Bjartell³, Jens Ceder⁴, Oskar Vilhelmsson Timmermand⁵

Affiliations

¹ Lund University, Faculty of Medicine, Department of Clinical Sciences Lund, Oncology and pathology, Lund, Sweden; Lund University, Faculty of Medicine, Department of Clinical Sciences Lund, Section for Pediatrics, Lund, Sweden; Department of Neonatology, Skåne University Hospital, Lund, Sweden.
² Lund University, Faculty of Medicine, Department of Clinical Sciences Lund, Medical Radiation Physics, Lund, Sweden.
³ Lund University, Faculty of Medicine, Department of Translational Medicine, Urological Cancers, Malmö, Sweden.
⁴ Lund University, Faculty of Medicine, Department of Clinical Sciences Lund, Oncology and pathology, Lund, Sweden.
⁵ Lund University, Faculty of Medicine, Department of Clinical Sciences Lund, Oncology and pathology, Lund, Sweden. Electronic address: [email protected].

PMID: 38968772
DOI: 10.1016/j.bbrc.2024.150324

Abstract

Ras homolog gene family member C (RhoC) is a GTPase involved in cell migration, implicated in epithelial-mesenchymal transition and treatment resistance and metastasis of cancer. For example, RhoC has been shown to be involved in resistance to radiation in cervical carcinoma. Here, the effect of X-ray irradiation on RhoC expression in prostate cancer (PCa) xenografts was investigated in both xenografts in regression and relapse. Male BALB/cAnNRj-Foxn1^nu/nu mice were inoculated with 4-6 million LNCaP-FGC cells and established xenografts were irradiated with X-rays (200 kV, 1 Gymin^-1), 5, 10 or 15 Gy using a Gulmay Medical X-ray system. Expression of RhoC and Ki67, a known proliferation marker, was investigated in xenografts, given 15 Gy, 7 days (midst response as measured by size) or 3 weeks (relapse) post irradiation. Staining was quantified using the Halo software (v2.3.2089.34) with the Indica Labs - cytonuclear v1.6 algorithm. RhoC and Ki67 staining was divided into weak, medium, and strong staining and the percentage of cells stained, single and dual staining, was quantified. The HALO software was further used to classify the tissue in each section so that analysis of RhoC and Ki67 expression in cancer cells, stroma and necrotic areas could be done separately. The results showed that RhoC expression in cancer and stroma cells was significantly higher in relapsed xenografts than in those in regression. This was not seen for Ki67 staining, where the percentage of stained cells were the same in regressing and relapsing tumors. RhoC could be a useful biomarker to confirm relapse following external beam radiation therapy.

Keywords: External beam radiation; Prostate cancer; Radioresistance; RhoC; Xenograft mouse model.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cell Line, Tumor
Humans
Ki-67 Antigen* / genetics
Ki-67 Antigen* / metabolism
Male
Mice
Mice, Inbred BALB C*
Mice, Nude*
Neoplasm Recurrence, Local* / metabolism
Prostatic Neoplasms* / genetics
Prostatic Neoplasms* / metabolism
Prostatic Neoplasms* / pathology
Prostatic Neoplasms* / radiotherapy
rho GTP-Binding Proteins / genetics
rho GTP-Binding Proteins / metabolism
rhoC GTP-Binding Protein* / genetics
rhoC GTP-Binding Protein* / metabolism

Substances

Ki-67 Antigen
rhoC GTP-Binding Protein
RHOC protein, human
rho GTP-Binding Proteins