Dados do Resumo

Título

"Immunohistochemical Analysis of ITIH2 and ENO1 Proteins in Canine Mammary Tumors: Correlation with Tumor Aggressiveness and Prognostic Potential"

Introdução

The investigation of breast cancer in female dogs, a relevant comparative model due to its biological similarity to human cancer, offers important perspectives on tumor mechanisms and the development of therapies. The ITIH2 protein, involved in the stabilization of the extracellular matrix, and enolase 1, a key in the glycolytic pathway and associated with cell invasion and metastasis, are promising biomarkers for diagnosis and prognosis, highlighting their importance in comparative oncology. Hamm et al., (2008) revealed that ITIH2 expression is clearly detectable in normal human breast tissue epithelium and maintained in hyperplastic gland epithelium and ductal carcinoma in situ, although weaker in ductal carcinoma in situ. Mishra et al., (2019) investigated the interaction between E6AP (ubiquitin ligase E6-associated protein) and ENO1, finding that these proteins interact predominantly in the cytoplasmic periphery of breast cancer cells. According to Didiasova et al., (2015) increased levels of the ENO-1 protein were found in ductal carcinoma of the breast and in the plasma cell membrane of the highly metastatic breast cancer lineage, MDA-MB-231.

Objetivo

To validate, by immunohistochemistry, the unique and abundant proteins Inter-alpha-trypsin Heavy Chain Inhibitor H2 (ITIH2) and Alpha-enolase (ENO1), previously identified in a proteomic study, and to investigate their relationship with the outcome and potential prognosis of mammary tumors in.

Métodos

A total of 51 samples of mammary tissue from female dogs were selected, divided into three groups: control (n=5), benign tumors (n=19) and malignant tumors (n=27). The samples were submitted to immunohistochemical technique, with the primary antibodies Anti-ITIH2 (polyclonal, 1:300 dilution) and Anti-ENO1 (EPR6854 clone, monoclonal, 1:3000 dilution), followed by HRP peroxidase and DAB staining. Microscopic analysis was performed with the IMAGE J software, which quantified DAB and hematoxylin staining, classifying the samples into expression categories, generating a histoscore (HS) for each. HS was calculated using the formula: HS=(1×% of low positive cells)+(2×% of positive cells)+ (3×% of high positive cells).

Resultados

Immunohistochemical analyses revealed that ITI2 demonstrated a marking predominantly in the extracellular space; ENO1 exhibited intense cytoplasmic staining. Histoscore values ranged from 0-146.48; and 18.44-197.38; for ITIH2 and ENO1, respectively. ROC curves were generated and, efferent to ITI2, the area under the curve (AUC)=0.67±0.07, CI=95% [0.53-0.80], with sensitivity of 65.22% and specificity of 80%, the cutoff was of histoscores lower than 44.5. For ENO1 AUC=0.64± 0.14, CI=95% [0.37-0.92], with a sensitivity of 76.09% and specificity of 60%, the cutoff was histoscores lower than 127.9.

Conclusões

There was a trend towards more intense labeling of the ITIH2 and ENO1 proteins in more aggressive tumors with a poor prognosis, but without statistical difference. Although the results suggest a possible correlation between these proteins and tumor aggressiveness, there is a need for further studies. This work is a pioneer in dogs and the recognition of the importance of ITIH2 and ENO1 can contribute to the implementation of new diagnostic and therapeutic strategies.

Financiador do resumo

National Council for Scientific and Technological Development (CNPq)- Grant identification number: 131890/2023-9

Palavras Chave

Breast cancer; biomarker; Predictions