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Expression patterns of the slit subfamily mRNA in canine malignant mammary tumors
Toshihiko Tanno1, Yuchie Tanaka, Takaaki Sugiura
1Laboratory of Cellular and Molecular Biology, Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Japan.
Abstract:
Slit, a secreted protein, functions as a chemorepellent factor in axon guidance and neuronal migration and as an inhibitor in leukocyte chemotaxis. In humans, slit2 protein attracts endothelial cells and promotes tube formation in the tumor angiogenic mechanism. In this study, we cloned a part of the canine slit subfamily and examined the expression of slit subfamily mRNAs in 3 normal canine mammary glands and 11 mammary tumor samples by RT-PCR. The cloned part of the slit gene sequences showed high similarity to those of the human, mouse, and rat. The mRNAs were expressed at low levels in the normal mammary gland. The expression levels of slit1 mRNA were low in both the normal and tumor tissues. In contrast, the expression of slit2 mRNA increased in most of the malignant mammary tumors, and an increase in slit3 mRNA expression was observed in 2 of the malignant mixed tumors. These results suggest that the expression of slit2 plays an important role in tumor angiogenesis in canine mammary gland tumors and that slit2 can be a putative marker for malignancy diagnosis of these tumors.
Insights
Canine mammary tumors show increased expression of slit2 mRNA, suggesting its role in tumor angiogenesis. Slit2 may serve as a diagnostic marker for malignancy in these canine tumors.
Area of Science:
- Molecular Biology
- Oncology
- Veterinary Medicine
Background:
- Slit proteins are secreted factors involved in cell guidance and migration.
- Slit2 protein in humans promotes tumor angiogenesis by attracting endothelial cells.
- The role of Slit subfamily members in canine mammary gland tumors is largely unexplored.
Purpose of the Study:
- To investigate the expression of Slit subfamily mRNAs in normal and malignant canine mammary tissues.
- To determine the potential role of Slit2 in canine mammary tumor angiogenesis.
- To evaluate Slit2 as a potential diagnostic marker for canine mammary tumors.
Main Methods:
- Cloning of a portion of the canine Slit subfamily genes.
- Quantitative analysis of Slit1, Slit2, and Slit3 mRNA expression using RT-PCR.
- Comparison of Slit mRNA levels in normal mammary glands versus mammary tumor samples.
Main Results:
- Canine Slit gene sequences showed high similarity to other mammalian species.
- Slit1 mRNA was expressed at low levels in both normal and tumor tissues.
- Slit2 mRNA expression was significantly upregulated in most malignant mammary tumors, while Slit3 showed increased expression in some malignant mixed tumors.
Conclusions:
- Slit2 expression is elevated in malignant canine mammary tumors, indicating its involvement in tumor angiogenesis.
- Slit2 may function as a prognostic or diagnostic biomarker for malignancy in canine mammary gland tumors.
