Supplementary Material for: A Mechanistic Study of the Effect of Doxorubicin/Adriamycin on the Estrogen Response in a Breast Cancer Model

<strong><em>Objective:</em></strong> Estrogen treatment limits the cytotoxic effects of chemotherapy in estrogen receptor-positive (ER+) breast cancer cell lines, suggesting that estrogen pathway signaling may confer chemotherapeutic resistance. This study investigates the molecular responses of ER+ breast cancer cell lines to the chemotherapeutic agent, doxorubicin, in the presence or absence of estrogen. <b><i>Methods:</i></b> ER+ MCF-7 and T47-D cells were cultured in hormone-starved or estrogen-containing media with or without doxorubicin at concentrations mimicking the low concentrations seen in plasma and tumor microenvironments in humans following typical bolus administration. Protein levels, phosphorylations, and interactions of estrogen-signaling molecules were assessed following these treatments, as well the effects of ER signaling inhibitors on cell proliferation. <b><i>Results:</i></b> Surprisingly, estrogen and doxorubicin co-treatment markedly induced pro-growth alterations compared to doxorubicin alone and modestly enhanced estrogen alone-induced changes. Several inhibitors suppressed cell proliferation in the presence of doxorubicin and estrogen. <b><i>Conclusions:</i></b> These findings demonstrate that molecular changes caused by doxorubicin in ER+ breast cancer cells can be reversed by estrogen, providing molecular evidence for the poorer responses of ER+ tumors to doxorubicin in the presence of physiologic estrogen levels. Our results also suggest that the addition of drugs targeting the ER, EGFR, the SFKs, MEK, PI3K, and/or the MMP proteins to a conventional chemotherapy regimen may improve chemosensitivity

Erratum: β-Globin Gene Cluster Haplotypes in a Cohort of 221 Children with Sickle Cell Anemia or Sβ⁰-Thalassemia and Their Association with Clinical and Hematological Features

<i>Background/Aims:</i> β^S-Haplotype prevalence and its associations with clinical and hematological characteristics were assessed in Brazilian children with sickle cell anemia or Sβ⁰-thalassemia. <i>Methods:</i> A retrospective randomized cohort study was undertaken with 208 SS and 13 Sβ⁰-thalassemia children derived from the Newborn Screening Program of the state of Minas Gerais. β^S-Haplotypes were determined by PCR-RFLP. <i>Results:</i> Thirty-nine percent of the SS subjects had the CAR/CAR genotype, 33% had CAR/Ben, 24% had Ben/Ben, 1% had CAR/Atp, 1% had Ben/Atp, and 1% had Arab-Indian/Ben; 1% could not be characterized. Of the Sβ⁰-thalassemia children, 5 were CAR/undefined, 2 were Ben/undefined, and 1 was CAM/undefined. There was no significant association between β^S-haplotypes and the total Hb, Hb F, MCV, MCH, WBC, and reticulocyte count among the SS children. Likewise, no significant association was detected between β^S-haplotypes and the frequency of acute chest syndrome episodes, blood transfusions, splenic sequestration, or cerebrovascular disease (high-risk/conditional transcranial Doppler ultrasonography or clinical stroke). A limited number of Sβ⁰-thalassemia children precluded valid analyses. <i>Conclusions:</i> The prevalence of β^S-haplotypes in this study is in agreement with the historical records of African slaves brought to the state of Minas Gerais. Furthermore, β^S-haplotypes CAR and Ben were not associated with any analyzed feature of children with sickle cell anemia