Fig 2: SHP-2 mediates the growth enhancing activity of and interacts with SLAMF8 in ALK-positive ALCL cells. (A) The effects of SLAMF8 knockdown on SHP-2 activation in human ALCL cell lines. SHP-2 ELISA (n = 3). *P < 0.05, compared to control cells. (B) The effects of the SHP-2 inhibitor PHPS1 on the cell growth of human ALCL cell lines. CCK-8 assay (n = 3). *P < 0.05, compared to control cells. (C) Interaction between SLAMF8 and SHP-2 or ALK in human cell lines. The DuoLink in situ kit. Red dots indicate the interaction between SLAMF8 and SHP-2 or ALK. Bars; 10 μM. (D) Interaction between SLAMF8 and SHP-2 in ALK-positive ALCL cell lines treated with crizotinib or PHPS1. Red dots indicate the interaction between SLAMF8 and SHP-2. Bars; 10 μM.

Fig 3: SLAMF8 is expressed in human ALCL cell lines Karpas299 and SU-DHL-1 and in human ALCL pathological samples. (A) RT-PCR for cell lines. Cropped gels are shown and the gels were run under the same conditions. U937 is used as a positive control, and K562 is used as a negative control. (B) Immunoblotting for cell lines. Cropped blots are shown and the gels were run under the same conditions. U937 is used as a positive control, and K562 is used as a negative control. (C) RT-PCR for crizotinib-treated ALCL cell lines. Cropped gels are shown and the gels were run under the same conditions. The band intensities were analyzed and the relative SLAMF8/GAPDH ratio was calculated. *P < 0.05, compared to ALCL cells treated with crizotinib 0 h. (D) Immunoblotting for crizotinib-treated ALCL cell lines. Cropped blots are shown and the gels were run under the same conditions. The band intensities were analyzed and the relative SLAMF8/GAPDH ratio was calculated. *P < 0.05, compared to ALCL cells treated with crizotinib 0 h. (E) Immunohistochemistry. Representative cases are shown. H&E, hematoxylin and eosin. (F) RT-PCR for pathological specimens. Total mRNAs from macro-dissected samples were used. Cropped gels are shown and the gels were run under the same conditions. (G) The association between SLAMF8 protein expression and clinical parameters, gender, and ALK expression.

Fig 4: Gene set enrichment analysis (GSEA). The full list of gene sets enriched in samples with DOCK2 (A), NCKAP1L (B), IL2RG (C), SLAMF8 (D), CD180 (E), and PTPRE (F) highly expressed.

Fig 5: SLAMF8 knockdown decreased the growth of ALK-positive ALCL cell lines. (A) SLAMF8 knockdown in human ALCL cell lines. Cropped blots are shown and the gels were run under the same conditions. (B) The effects of SLAMF8 knockdown on cell growth and apoptosis in human ALCL cell lines. CCK-8 assay and Annexin V-FITC staining/propidium iodine incorporation (n = 3, respectively). *P < 0.05, compared to control cells.