PRMT5 is overexpressed in canine lymphoma subtypes.

(A) Photomicrographs of representative histologic sections from primary canine lymphomas (n = 337) and normal donor (ND) lymph node samples (n = 40) corresponding to Table 1. Anti-PRMT5 IHC. Representative ND tissue shows weak cytoplasmic staining with lack of nuclear staining for PRMT5, in comparison to lymphoma samples with either weak cytoplasmic staining, strong cytoplasmic staining, or presence of nuclear staining for PRMT5. (B) Quantitative RT-PCR showing the relative fold change expression of PRMT5 and MYC mRNA in primary canine B-cell (n = 7) and T-cell (n = 2) lymphoid biopsy samples compared to ND samples (n = 3). Dots represent different lymphoid samples from different donors. Statistical significance evaluated using multiple paired two-tailed Student’s t-Test assuming unequal variance. The respective p-values are indicated (*p < 0.05, **p < 0.01) (C) Immunoblot analysis of PRMT5 and MYC indicate elevated protein expression in primary canine B-cell lymphoma biopsies (n = 5) compared to ND lymphoid tissue. One of two primary T-cell lymphoma specimens showed elevated PRMT5 and MYC protein levels. PRMT5, MYC, and α/β-TUBULIN were ran on separate gels using the same protein lysates. Immunoblots were detected using film and HRP conjugated secondary antibodies. (D) Immunoblot analysis of PRMT5 and MYC in the canine B-cell lymphoma cell lines (17–71 and CLBL-1) and T-cell lymphoma cell line (OSW). Compared to isolated B- and T-lymphoid cells from ND peripheral blood, canine lymphoma cell lines overexpress protein levels of PRMT5 and MYC, respectively. Immunoblots were detected with fluorescently labeled Licor IRDye secondary antibodies. For (C) and (D) protein expression was quantified by the ratio of target protein to loading control and normalized to ND.