Analysis of PTPN1 mRNA variants in cHL. (A) Schematic representation of the identified and sequenced PTPN1 cDNA variants derived from primary cHL cases and cHL cell lines. (B) Endpoint PCR results of the amplified PTPN1 cDNA from laser-microdissected HRS cells of selected primary cHL cases. The PCR signal related to full-length PTPN1 mRNA (I) and the band corresponding to the PTPN1Δ6 mRNA (II) are indicated. (C) Percentage of the PTPN1Δ6 mRNA based on the whole PTPN1 mRNA levels in 24 cases from the cHL cohort measured by qPCR analyses. Three different groups are defined: group I, very low relative PTPN1Δ6 mRNA expression (cases 15, 19, 21, 25, 72, 186; red bars); group II, low relative PTPN1Δ6 mRNA expression (cases 4, 5, 6, 10, 17, 81, 82, 83, 158; blue bars); and group III, high relative PTPN1Δ6 mRNA expression (cases 9, 29, 34, 39, 52, 54, 59, 69, 86; light green bars). (D) Percentage of the PTPN1Δ6 mRNA based on the whole PTPN1 mRNA levels in the different cHL cell lines without and after stimulation with serum for 6 hours, measured by qPCR analyses. Significances are calculated in comparison with the control (0 hours) values. *P ≤ .05; **P ≤ .01; ***P ≤ .001. (E) Percentage of the PTPN1Δ6 mRNA based on the whole PTPN1 mRNA levels in other lymphoma cell lines (PMBL, ABC-DLBCL, GC-DLBCL) measured by qPCR analyses. (F) Percentage of the PTPN1Δ6 mRNA based on the whole PTPN1 mRNA levels in 8 control LCL cell lines (left) and microdissected B cells from lymph node sections. GC, germinal center; MZ, mantle zone (right part). (D-F) The dashed line marks the relative PTPN1Δ6 mRNA expression level of 0.4% observed in the group of laser-captured HRS cells with very low relative PTPN1Δ6 mRNA expression.