![Figure 1. Expression of hERG1 channels by primary leukemic cells and cell lines. (A) Levels of hERG1 mRNA expression in normal B lymphocytes (CD19+), Epstein-Barr virus-infected B lymphocytes, ALL cell lines (REH, RS4;11, 697), and primary samples from BCP-ALL (n = 63) patients measured by SYBR Green RQ-PCR. Levels of the hERG1 transcript were normalized to levels of the corresponding transcript in normal CD19+ cells. Mean values for hERG1 expression are reported; the box plot at the far right shows median, 25th and 75th quartile, and extreme outlier values. (B) Surface expression of hERG1 by flow cytometry in B-ALL cell lines. (C) Surface expression of hERG1 by flow cytometry in primary BCP-ALL and evaluation of the MFI value. MFI was calculated by dividing the MFI of the hERG1 molecule by the MFI of the respective negative control. (D) Surface expression of hERG1 by flow cytometry in primary leukemic cells gated on CD19+. A representative CD10+ BCP-ALL sample is shown in the left panel and a representative CD10− BCP-ALL sample is shown on the right. Top panels, plot of hERG1 expression showing both the anti-hERG1 antibody (solid line) and the control isotype labeling (dotted line). Bottom panels, dot plots relative to hERG1 expression in conjunction with that of CD10 in the leukemic cells. (E) Surface expression of hERG1 by flow cytometry in normal CD19+ CD10+ bone marrow cells. Top and bottom panels are as in panel D. (f) IHERG in 697 cells. Current traces show IHERG elicited at −120 mV, after conditioning for 10 seconds at a Vm between −70 and 0 mV (10-mV step). For clarity, only 5 current traces are shown (those obtained after conditioning at −70, −60, −40, −30, and 0 mV). IHERG was measured in [K+]o = 40mM to increase the current amplitude at −120 mV, and was isolated by subtracting the background currents from the total currents obtained in the presence of 2μM WAY 123398. The right panel shows the corresponding activation curve in a representative experiment. Black circles are peak current values measured at the indicated conditioning potential and normalized to the maximal current. Continuous line is the Boltzmann curve best fitting the experimental data. The midpoint of activation was −47 mV. These results are representative of 5 similar experiments carried out in the same cell batch, in which the average midpoint of activation was −47 ± 1.2 mV.](https://ash.silverchair-cdn.com/ash/content_public/journal/blood/117/3/10.1182_blood-2010-01-262691/4/zh89991064740001.jpeg?Expires=1735818498&Signature=jwiw6E-m-TEKsY8gBFd4oQDMJLrClLxEWxTs-R7UIr3PRuOytt2HV0kJWnjlo2XsUUSdo-rFEKeW~B3uG2X3pSlS4GRhMQhaq15fnnARXuZlVWGBIJDRM6lMZjisp~UCWK56H1uMCfq3a7uzNlneENxxu-ScwnxT81t1HBzrfLUmxHQvFlphCy0i9fdf0IbywsUrk1RBiGMIDbJ3B6EKTF-sYDJShAyxQT857mD0z9I0Bezmz18XLHLNM1KVu6Ic4OnGrLJK9FmBRCfQu3vzFAKXalBRFHyQpQk6NDaaAiz28zep23WYjAnaciACRQvaxtRbMZNSBHQ3vyyCW6eyzw__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
Expression of hERG1 channels by primary leukemic cells and cell lines. (A) Levels of hERG1 mRNA expression in normal B lymphocytes (CD19+), Epstein-Barr virus-infected B lymphocytes, ALL cell lines (REH, RS4;11, 697), and primary samples from BCP-ALL (n = 63) patients measured by SYBR Green RQ-PCR. Levels of the hERG1 transcript were normalized to levels of the corresponding transcript in normal CD19+ cells. Mean values for hERG1 expression are reported; the box plot at the far right shows median, 25th and 75th quartile, and extreme outlier values. (B) Surface expression of hERG1 by flow cytometry in B-ALL cell lines. (C) Surface expression of hERG1 by flow cytometry in primary BCP-ALL and evaluation of the MFI value. MFI was calculated by dividing the MFI of the hERG1 molecule by the MFI of the respective negative control. (D) Surface expression of hERG1 by flow cytometry in primary leukemic cells gated on CD19+. A representative CD10+ BCP-ALL sample is shown in the left panel and a representative CD10− BCP-ALL sample is shown on the right. Top panels, plot of hERG1 expression showing both the anti-hERG1 antibody (solid line) and the control isotype labeling (dotted line). Bottom panels, dot plots relative to hERG1 expression in conjunction with that of CD10 in the leukemic cells. (E) Surface expression of hERG1 by flow cytometry in normal CD19+ CD10+ bone marrow cells. Top and bottom panels are as in panel D. (f) IHERG in 697 cells. Current traces show IHERG elicited at −120 mV, after conditioning for 10 seconds at a Vm between −70 and 0 mV (10-mV step). For clarity, only 5 current traces are shown (those obtained after conditioning at −70, −60, −40, −30, and 0 mV). IHERG was measured in [K+]o = 40mM to increase the current amplitude at −120 mV, and was isolated by subtracting the background currents from the total currents obtained in the presence of 2μM WAY 123398. The right panel shows the corresponding activation curve in a representative experiment. Black circles are peak current values measured at the indicated conditioning potential and normalized to the maximal current. Continuous line is the Boltzmann curve best fitting the experimental data. The midpoint of activation was −47 mV. These results are representative of 5 similar experiments carried out in the same cell batch, in which the average midpoint of activation was −47 ± 1.2 mV.
