RT-PCR-based tyrosine kinase display profiling of canine melanoma: IGF-1 receptor as a potential therapeutic target

Abstract

Canine malignant melanoma (CMM) resembles human malignant melanoma in terms of metastatic behavior, refractoriness to standard therapy, and tumor antigen expression but it is largely unknown how CMM resembles human melanoma with regard to molecular pathogenesis and cellular signaling. No attempt has been made to systematically define the repertoire of tyrosine kinases (TKs) expressed in CMM. This study used a reverse transcription-PCR display technique to evaluate the expression of multiple TKs in the 17CM98 CMM cell line. RT-PCR was performed using degenerate primers coding for highly conserved regions flanking the kinase domains of many TKs and the repertoire of TKs expressed was determined using standard molecular cloning techniques. Sequencing 46 clones yielded canine homologs of insulin-like growth factor-1 receptor (IGF-1R) (50%), JAK1 (17%), PDGFR-a (11%), FGFR1 (9%), Axl (7%), Abl (4%), and PTK2 (2%). Interestingly, IGF-1R, JAK1, and Axl were detected in human melanoma using similar techniques, supporting the cross-species validity of this assay. Given the abundance of IGF-1R clones, we determined the biological effect of rhIGF-1 in 17CM98 cells. IGF-1 stimulated cell proliferation and vascular endothelial growth factor production in 17CM98, and addition of the IGF-1R inhibitor ADW742 abrogated IGF-1-induced phenotypic changes. Expression of IGF-1R mRNA was detected in five of five additional CMM cell cultures, and IGF-1R protein was detected in five of six primary tumors evaluated, suggesting that IGF-1R expression may be common in CMM and may provide a novel target for future therapy. In conclusion, this study suggests that similar TKs are expressed in human and canine melanoma, and shows potential antitumor effects of IGF-1R inhibition in CMM.

Increased expression of insulin-like growth factor-1 receptor is correlated with worse survival in canine appendicular osteosarcoma

“…Moreover, its expression induces chemoresistance and anti-apoptotic processes (Grothey et al, 1999). In veterinary oncology, IGF receptors have been studied only in canine mammary tumours (Dolka et al, 2011;Yee, 2012), insulinoma (Buishand et al, 2012) and canine melanomas (Thamm et al, 2010). In canine mammary tumours, the high level of IGF-1R expression was correlated to high oestrogen receptor (ER) alpha and progesterone receptor (PR) expression and to the expression of anti-apoptotic molecules such as p53 and Bax (Dolka et al, 2011).…”

“…In veterinary medicine, IGF-1R has been studied in canine mammary tumours (Klopfleisch et al, 2010;Dolka et al, 2011), in melanomas (Thamm et al, 2010) and in insulinomas (Buishand et al, 2012) as well as in OSA cell lines (MacEwen et al, 2004), However, there are no data about its role in canine OSA as a prognostic factor and as a potential specific target for TKIs. The aim of this study was to investigate IGF-1R expression in canine OSA tissues and cell lines, to evaluate its prognostic value in relation to clinical outcome, and to test the in vitro effects of IGF-1R inhibition in canine OSA cell lines.…”

Canine Melanoma Diagnosis

“…Moreover, insulin-like growth factor 1 receptor (IGF1R), which controls about 50% of the cell size, 2 was shown to be expressed in canine melanomas. 32 Interestingly, RACK1 builds protein complexes with IGF1R in other cell types (reviewed in Adams et al 1 ). Besides, it is accepted that nuclear atypia and proliferative activity are significantly correlated with outcome in canine melanocytic neoplasms at any anatomical site.…”

Capromorelin: a ghrelin receptor agonist and novel therapy for stimulation of appetite in dogs

“…IGF‐1 receptors have been shown to be present on canine malignant melanoma cell cultures in vitro (Thamm et al . ) and elevated serum and tumour GH and IGF‐1 have been associated with the malignant phenotype of canine mammary cancer (Queiroga et al . ).…”

“…GH and IGF-1 and their receptors have been implicated in possible promotion of tumour growth (Perry & Wang 2012). IGF-1 receptors have been shown to be present on canine malignant melanoma cell cultures in vitro (Thamm et al 2010) and elevated serum and tumour GH and IGF-1 have been associated with the malignant phenotype of canine mammary cancer (Queiroga et al 2010). In a 1-year safety study in normal Beagles, there was no evidence of tumour initiation from high daily doses of capromorelin (Zollers et al 2016a).…”