Proceeding of Veterinary and Animal Science Days 2016, 8th- 10th June, Milan, Italy 

HAF © 2013 

Vol. III, No. 1s  ISSN: 2283-3927 

   

 

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Keywords 

Leukotriene A4 hydrolase, 

immunohistochemistry, RT-PCR, 

dog, melanoma, oral cavity 

 

CORRESPONDING AUTHOR 

Laura Nordio 

laura.nordio@unimi.it 

 

JOURNAL HOME PAGE 

riviste.unimi.it/index.php/haf 

LTA4H expression in canine oral melanomas: 

methodological set up and preliminary 

results. 

 

L. Nordioa*, F. Genovaa, V. Serraa, C. Giudicea  

 

 

a Department of Veterinary Medicine, University of Milan, via Celoria 10, Milan, 
Italy 

 

 Abstract 

Leukotriene A4 hydrolase (LTA4H) is a hydrolytic enzyme which converts leukotriene A4 into 

leukotriene B4 inside the arachidonic acid cascade. Besides playing a well-known role in inflammation, 

it has also been investigated for possible implications in different types of tumors, including canine uveal 

melanoma (Chen et al., 2004; Malho et al., 2013). In the present study, we set up RT-PCR and 

immunohistochemical protocols to investigate the expression of LTA4H gene and protein, respectively, 

in formalin fixed paraffin embedded (FFPE) specimens of canine melanomas. 16 samples of canine oral 

melanomas were histopathologically evaluated and divided in two subgroups based on morphological 

criteria of malignancy. RT-PCR protocols for the target gene LTA4H were set up on frozen and FFPE 

samples of the same tumor. Immunohistochemical investigation of LTA4H protein was performed with 

a mouse monoclonal antibody anti-LTA4H (clone 1E9). Preliminary tests were carried out to define the 

protocol: with and without bleaching, with different unmaskings, with different serial dilutions of the 

primary antibody. RT-PCR set up resulted in comparable good efficiency on both frozen and FFPE 

samples. Final immunohistochemical protocol included: hydrogen peroxide bleaching, water bath 

unmasking and 1:100 dilution of the primary antibody. Positive immunostaining for LTA4H was present 

in neoplastic cells of all melanoma samples, with variable localization and intensity. These preliminary 

results encourage future applications of the studied techniques to quantify differential expression of 

LTA4H in canine melanomas both at molecular and histological level. Laboratory results will be 

compared with follow up data, in order to verify if LTA4H can be proposed as a valuable prognostic 

marker. 
 

References 

Chen, X., Wang, S., Wu, N., Yang, C.S., 2004. Leukotriene A4 hydrolase as a target for cancer prevention and therapy. Current 

Cancer Drug Targets 4, 267-283. 

Malho, P., Dunn, K., Donaldson, D., Dubielzig, R.R., Birand, Z., Starkey, M., 2013. Investigation of prognostic indicators for 

human uveal melanoma as biomarkers of canine uveal melanoma metastasis. J. Small Anim. Pract. 54, 584-593. 

http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en