Utility of Serum Ki-67 as a Marker for Malignancy in Dogs

Abstract

Tumour markers are scarcely used in veterinary medicine, although they are non-invasive, contribute to a faster diagnosis and new therapeutic options. The nuclear protein Ki-67 is absent in G0-phase but is detectable throughout all active phases of the cell cycle. Consequently, it is used as a marker for the proliferating cell fraction of a cell population and thus could indicate neoplastic tissue present. Our study is designed to show whether Ki-67 can be considered as a potential canine serum tumour marker for veterinary medicine. We measured serum concentrations of Ki-67 in dogs with various malignant tumours (carcinomas (n = 35); sarcomas (n = 26); lymphomas (n = 21)) using a commercially available quantitative sandwich ELISA from mybiosource. Dogs with malignant tumours showed significantly higher serum Ki-67 concentrations compared to healthy dogs (n = 19) and non-neoplastic diseased dogs (n = 26). No significant difference in serum Ki-67 concentration was detected between carcinoma, sarcoma, and lymphoma, nor between mammary adenocarcinoma and adenoma. In our investigations we also included some inflammatory parameters measured in blood, such as neutrophils, lymphocytes, and monocytes, and gained mixed results. The results of our study suggest that Ki-67 may be useful as a potential serum tumour marker, providing information about the presence of malignancies in a dog.

Molecular Markers in Canine Mammary Tumors

“…A fundamental and most recognizable hallmark of cancer, including breast cancer, is sustaining proliferative signaling, which comprises dysregulation of the cell cycle [12]. Certain molecular factors are distinctively regulated during this process and, therefore, can potentially be used as biomarkers of a particular cancer type and subtype, stage, or dysregulated pathway [12][13][14].…”

“…It is commonly used as a proliferation marker in breast cancer, including CMTs. Ki-67 is a nuclear, non-histone protein that can be differentially detected through distinct cell cycle phases [13]. Specifi cally, levels of Ki-67 protein were correlated with G1, S, G2 and mitosis (active stages of the cell cycle), markedly detectable in the last one and absent in quiescent cells in the G0 phase.…”

“…This explains why Ki-67 is localized in the nucleus during the interphase, while in mitosis, it is mainly detected on the chromosomes' surface. However, some evidence suggests that Ki-67 can be detected to a certain degree at the ribosomal RNA transcription area, regulating its synthesis [13,[15][16][17].…”

Expression of Foxp3 in Fibromas and Fibrosarcomas of Skin and Subcutaneous Tissue in Dogs

“…Latest research presents the possibility of evaluating the presence of Ki-67 not only in neoplastic tissues but the canine serum as well. This provides the potential of assessing the risk of neoplastic disease occurrence in animals (14). Such research reflects on the continuous development of veterinary medicine and the necessity to implement advanced solutions in daily practice.…”

Studies on the association of malondialdehyde as a biomarker for oxidative stress and degree of malignancy in dogs with mammary adenocarcinomas

“…According to previous literature, at least 40–50% of these tumours appear to be malignant (Sorenmo, 2003 ). There is a growing interest in the investigation of pathogenesis and prognostic biomarkers for the assessment of malignancy (Burrai et al., 2022 ; Estaller et al., 2022 ; Michishita et al., 2011 ; Montalli et al., 2017 ; Rasotto et al., 2017 ; Santos et al., 2023 ). The aetiopathogenesis of tumours of the mammary gland in dogs is not yet fully understood, although genetic, nutritional and hormonal factors are discussed (Sarli et al., 2002 ; Sorenmo, 2003 ).…”