Erratum to: Comparing the two leading erythroid lines BEL-A and HUDEP-2

With reference to our paper published in the August issue 2020 of Haematologica,¹ during the final processing of the manuscript the labeling of Figure 2E got accidentally inverted. On both the BEL-A and HUDEP-2 graphs, γ and β globin labels are the wrong way around. The corrected panel E of Figure 2 is shown here.

Figure 2.Globin subunit expression by BEL-A and HUDEP-2. (A). Western blots of lysates obtained from late stage (day 10) HUDEP-2 in EDM media, HUDEP-2 and BEL-A in Bristol media and adult peripheral blood (PB; day 17) erythroid cells incubated with antibodies to α-, β- and γ-globin (sc-514378; sc-21757; sc-21756; all Santa Cruz). (B) Analysis of α-, β- and y-globin mRNA levels in BEL-A and HUDEP-2 in Bristol media on day 6 of culture by quantitative PCR (qPCR). Target gene expression was normalized to PABPC1 reference gene (using the 2-AACt method) and compared to a BEL-A control sample. Results are means ± standard deviation (SD), N=4. TaqMan gene expression assays used were: HBA (Hs00361191_g1), HBB (Hs00747223_g1), HBG (Hs00361131_g1) and PABPC1 (Hs00743792_s1) (Fisher Scientific). (C) H3K27ac chromatin immunoprecipitation (ChIP) was carried out in 5x10⁶ day 4 cells by fixing in 1% formaldehyde and performing immunoprecipitation (IP) with the ChIP Assay Kit (Merck Millipore) using 0.3 μg anti-H3K27ac (ab4729; Abcam). Enrichment at the HBG1/2 promoters (i) and control regions (ii) was determined using qPCR by comparing to a background control (hg19, chr16:6,002,736-6,002,834). Bars depict mean and SD for IP from 4 separate differentiations (circles). *Mann-Whitney rank sum P=0.0286. (D-E) Response of BEL-A and HUDEP-2 cells to hydroxyurea treatment. Hydroxyurea (H8627; Sigma) was added to cells at 50 μM every 2 days from four days prior to the start of differentiation until harvesting of cells on day 10 of differentiation. (D) Representative Western blot of cell lysates from ± hydroxyurea (HU) cultures incubated with antibodies to α-, β- and y-globin and (E) densitometric analysis of the bands obtained from at least 3 independent experiments normalized to α-globin expression (means ± SD). *P<0.05 two-tailed Student t test. (F-G) Expression of BCL11A, GATA1 and KLF1 by BEL-A and HUDEP-2. p-actin was used as a protein loading control. (F) Representative western blots of lysates obtained from cells at day 0, 2, 4 and 6 of BEL-A and HUDEP-2 cultures incubated with BCL11A (ab19487; Abcam), GATA1 (sc-266; Santa Cruz), KLF1 (sc-14034; Santa Cruz) and p-actin (A1978; Sigma) antibodies and (G) densitometric analysis of the bands obtained from 2 independent experiments normalized to p-actin expression and then compared to BEL-A day 0 (means ± SD).

Footnotes

• Received October 19, 2023
• Accepted October 19, 2023

Correspondence

J. Frayne jan.frayne@bristol.ac.uk