A longitudinal study of ABC transporter expression in canine multicentric lymphoma

Abstract

Background: A genetic predisposition for certain tumour types has been proven for some dog breeds. Some studies have suggested that this may also be true for the Golden retriever breed. The present study aimed to examine a possible existence of a tumour (type) predisposition in the Dutch population of Golden retrievers by evaluating annual estimated incidence rates compared to incidence rates from previous publications. A second aim was to evaluate whether incidences of various tumours differed as related to the diagnostic method chosen, being either cytology or histology. Results: Tumours submitted to Utrecht University during the period 1998-2004 diagnosed either by means of cytology (n = 2,529) or histology (n = 2,124), were related to an average annual Dutch kennel club population of 29,304 Golden retrievers. Combining individual tumours from both the cytological and the histopathological data-set resulted in an annual estimated incidence rate of 2,242 for 100,000 dog-years at risk regarding tumour development in general. The most common cytological tumor diagnoses were 'fat, possibly lipoma' (35%), mast cell tumour (21%) and non-Hodgkin lymphoma (10%). The most commonly diagnosed tumours by histology were mast cell tumour (26%), soft tissue sarcomas (11%) and melanoma (8%). Both the cytological and histopathological data-sets, showed variation; in patient age distribution, age of onset and incidence of various tumours. Conclusion: Comparing our data with previous reports in non-breed-specified dog populations, the Golden retriever breed shows an increased risk for the development of tumours in general, as well as an increased risk for the development of specific tumour types, including the group of soft tissue sarcomas. Variations in age, location and incidence of various tumours were observed between the two data-sets, indicating a selection bias for diagnostic procedure.

Hypoxia-activated prodrug TH-302 decreased survival rate of canine lymphoma cells under hypoxic condition

“…It has generally been thought that lymphomas in humans and dogs acquire multidrug resistance from the continuous activation of drug transporters, such as ABCB1 and ABCG2, after long-term exposure to anticancer drugs, inducing chemical tolerance in the patient [3, 27]. Interestingly, we have shown here that mild hypoxic stimulation also reduced the sensitivity to DOX of DOX-resistant lymphoma cells generated with conventional methods.…”

Clinical characteristics and outcome of dogs with presumed primary renal lymphoma

“…Finally, T‐cell phenotype appeared to predominate, which may have contributed to the poor chemotherapy response observed; intrinsic drug resistance is common with this form and is associated with increased ABCG2 expression (Zandvliet et al . ).…”

Canine T cell lymphoma treated with lomustine, vincristine, procarbazine, and prednisolone chemotherapy in 35 dogs

“…They found that dogs with T cell lymphoma had higher intrinsic drug resistance than dogs with B cell lymphoma and dogs with drug resistant T cell lymphoma had increased ABCG2 mRNA expression. ABCG2 plays a role in transport and cellular sensitivity to doxorubicin and has been associated with doxorubicin resistance in humans . These findings suggest that dogs with T cell lymphoma are less sensitive to doxorubicin and require non‐doxorubicin‐based protocols for the treatment of this disease.…”