Evaluation of 2D and 3D Erythroid Differentiation Protocols Using Sickle Cell Disease and Healthy Donor Induced Pluripotent Stem Cells

BACKGROUND

Sickle cell disease (SCD) is a highly prevalent genetic disease caused by a point mutation in the HBB gene, which can lead to chronic hemolytic anemia and vaso-occlusive events. Patient-derived induced pluripotent stem cells (iPSCs) hold promise for the development of novel predictive methods for screening drugs with anti-sickling activity. In this study, we evaluated and compared the efficiency of 2D and 3D erythroid differentiation protocols using a healthy control and SCD-iPSCs.

METHODS

iPSCs were subjected to hematopoietic progenitor cell (HSPC) induction, erythroid progenitor cell induction, and terminal erythroid maturation. Differentiation efficiency was confirmed by flow cytometry analysis, colony-forming unit (CFU) assay, morphological analyses, and qPCR-based gene expression analyses of HBB and HBG2.

RESULTS

Both 2D and 3D differentiation protocols led to the induction of CD34⁺/CD43⁺ HSPCs. The 3D protocol showed good efficiency (>50%) and high productivity (45-fold) for HSPC induction and increased the frequency of BFU-E, CFU-E, CFU-GM, and CFU-GEMM colonies. We also produced CD71⁺/CD235a⁺ cells (>65%) with a 630-fold cell expansion relative to that at the beginning of the 3D protocol. After erythroid maturation, we observed 95% CD235a⁺/DRAQ5- enucleated cells, orthochromatic erythroblasts, and increased expression of fetal HBG2 compared to adult HBB.

CONCLUSION

A robust 3D protocol for erythroid differentiation was identified using SCD-iPSCs and comparative analyses; however, the maturation step remains challenging and requires further development.

Arsenic Trioxide Triggers Apoptosis of Metastatic Oral Squamous Cells Carcinoma with Concomitant Downregulation of GLI1 in Hedgehog Signaling

Given the lack of advances in Oral Squamous Cell Carcinoma (OSCC) therapy in recent years, pharmacological strategies to block OSCC-related signaling pathways have gained prominence. The present study aimed to evaluate the therapeutic potential of Arsenic Trioxide (ATO) concerning its antitumoral effects and the inhibition of the Hedgehog (HH) pathway in OSCC. Initially, ATO cytotoxicity was assessed in a panel of cell lines. Cell viability, cell cycle, death patterns, and cell morphology were analyzed, as well as the effect of ATO on the expression of HH pathway components. After the cytotoxic assay, HSC3 cells were chosen for all in vitro assays. ATO increased apoptotic cell death and nuclear fragmentation in the sub-G1 cell cycle phase and promoted changes in cell morphology. In addition, the reduced expression of GLI1 indicated that ATO inhibits HH activity. The present study provides evidence of ATO as an effective cytotoxic drug for oral cancer treatment in vitro.

A-01 Changes in Fixational Eye Movements (FEMs) Following Concussion

Purpose: Identify changes in fixational eye movement (FEMs) outcomes following concussion and assess the association of FEMs outcomes with clinical outcomes including symptoms, neurocognitive, and vestibular/ocular motor. Methods: Participants included thirty-three individuals (13–27 years old; 54.5% female) diagnosed with concussion within the past 21 days. Concussion diagnosis was determined using current consensus guidelines. A tracking scanning laser ophthalmoscope (TSLO) was used to measure FEMS. Participants completed ImPACT, PCSS, and VOMS. Within-subjects changes in FEMS outcomes were calculated using paired-samples t-tests. A backwards stepwise linear regression to predict days to clearance was utilized with all FEMS outcomes as predictors. Results: MeanDriftH (slope of cumulative drift regression calculated horizontally; mean difference = 0.04; p = 0.03; Cohen’s d = 0.43) and drift proportion significantly changed over time (mean difference = 0.03; p = 0.03, d = 0.44). Average peak velocity of microsaccade (MsPkVel) predicted days to recovery (R = 0.26; p = 0.045; n = 24). MsPkVel and average duration of blink correlated with select reports of nausea on VOMS. Microsaccade frequency (r = −0.36; p = 0.04) correlated with NPC fogginess. Drift amplitude (DriftAmp) correlated with NPC distance (r = −0.41; p = 0.02) and VMS headache (r = 0.35; p = 0.04). MeanDriftH was negatively correlated with verbal memory (r = −0.44; p = 0.01), whereas DriftAmp was positively correlated (r = 0.50; p = 0.003). Bivariate contour ellipse area was correlated (r = 0.43; p = 0.01) with slower reaction time on ImPACT. Conclusions: FEMs outcomes demonstrated significant change and were useful in predicting recovery time following concussion. FEMs measurements may provide brief, objective data to augment current clinical assessment and inform prognosis for recovery. Future researchers should examine FEMS outcomes from pre- to post-concussion and explore age and sex differences.

Examining the Relationship between Biopsychosocial History and Clinical Profiles Following Concussion

Purpose

To determine if clinical risk factors (e.g., migraine history, motion sickness, concussion history) place an individual at risk for specific clinical profiles (e.g., posttraumatic migraine, vestibular) designated by a clinician following concussion.

Methods

Fifty (22M; 28F) symptomatic, concussed patients (17.02±3.14 years old) were evaluated within 21days post-injury. Demographics and medical history were obtained, including history of migraine, motion sickness, ADHD, learning disability (LD), oculomotor disorder, psychiatric diagnoses, and prior concussion. The presence of each clinical profile was determined by a clinician, based on synthesis of evaluation findings, including neurocognitive testing, symptom report, and vestibular/oculomotor screening results. Chi-square analyses were used to explore associations between risk factors and clinical profile post-injury.

Results

Chi-square analyses found that female sex was associated with increased odds (OR=5.25,95% CI[1.55, 17.77]) of vestibular clinical profile, X2(1, n=50)=7.55, p=.006. History of concussion was associated with increased odds (OR=7.10,95%CI[1.39,35.87]) of the PTM profile (X2[1, n=50]=6.56, p=.01) and increased odds (OR=9.85,95%CI[1.00,96.67]) of anxiety/mood profile (X2 1, n=50]=5.24, p=.022. Further, history of motion sickness was associated with increased odds OR=10.2,95%CI[1.2,86.69] of the PTM profile (X2[1, n=50]=6.11, p=.013). No other relationships were found.

Conclusion

Some clinical risk factors were associated with post-injury clinical profiles consistent with prior literature, while others were not. For example, females were more likely to have a vestibular profile. While motion sickness was associated with PTM, history of migraine was not. Concussion history, which has inconsistent findings for re-injury outcomes, was associated with increased likelihood of PTM and anxiety/mood profiles. Findings add to the literature supporting relationships among risk factors and clinical outcomes.

Potentially synbiotic fermented beverage with aqueous extracts of quinoa (Chenopodium quinoa Willd) and soy

The aim of this study was to develop a potentially synbiotic beverage fermented with Lactobacillus casei LC-1 based on aqueous extracts of soy and quinoa with added fructooligosaccharides (FOS). Five formulations with differing proportions of soy and quinoa extracts were tested. The viability of the microorganism, the pH, and the acidity of all formulations were monitored until the 28th day of storage at 5 ℃. The chemical composition of the extracts and beverages and the rheological and sensory properties of the final products were analyzed. Although an increase in acidity and a decrease in pH were observed during the 28 days of storage, the viability of the probiotic microorganism was maintained at 108 CFU·mL−1 in all formulated beverages throughout the storage period. An increase in viscosity and consistency in the formulations with higher concentrations of quinoa (F1 and F2) was observed. Formulation F4 (70% soy and 30% quinoa extracts) showed the least hysteresis. Formulations F4 and F5 (100% soy extract) had the best sensory acceptance while F4 resulted in the highest intention to purchase from a group of 80 volunteers. For chemical composition, F3 (50% soy and 50% quinoa extracts) and F4 showed the best results compared to similar fermented beverages. The formulation F4 was considered the best beverage overall.

Anti-CEA antibody fragments labeled with [(18)F]AlF for PET imaging of CEA-expressing tumors

A facile and rapid method to label peptides with (18)F based on chelation of [(18)F]AlF has been developed recently. Since this method requires heating to 100 °C, it cannot be used to label heat-sensitive proteins. Here, we used a two-step procedure to prepare (18)F-labeled heat-labile proteins using the [(18)F]AlF method based on hot maleimide conjugation. 1,4,7-Triazacyclononae-1,4-diacetate (NODA) containing a methyl phenylacetic acid group (MPA) functionalized with N-(2-aminoethyl)maleimide (EM) was used as a ligand which was labeled with [(18)F]AlF and then conjugated to the humanized anti-CEA antibody derivatives hMN-14-Fab', hMN-14-(scFv)2 (diabody), and a Dock-and-Lock engineered dimeric fragment hMN-14 Fab-AD2 at room temperature. The in vivo tumor targeting characteristics of the (18)F-labeled antibody derivatives were determined by PET imaging of mice with s.c. xenografts. NODA-MPAEM was radiolabeled with [(18)F]AlF at a specific activity of 29-39 MBq/nmol and a labeling efficiency of 94 ± 2%. The labeling efficiencies of the maleimide conjugation ranged from 70% to 77%, resulting in [(18)F]AlF-labeled hMN14-Fab', hMN14-Fab-AD2, or hMN14-diabody with a specific activity of 15-17 MBq/nmol. The radiolabeled conjugates were purified by gel filtration. For biodistribution and microPET imaging, antibody fragments were injected intravenously into BALB/c nude mice with s.c. CEA-expressing LS174T xenografts (right flank) and CEA-negative SK-RC-52 xenografts (left flank). All [(18)F]AlF-labeled conjugates showed specific uptake in the LS174T xenografts with a maximal tumor uptake of 4.73% ID/g at 4 h after injection. Uptake in CEA-negative SK-RC-52 xenografts was significantly lower. Tumors were clearly visualized on microPET images. Using a [(18)F]AlF-labeled maleimide functionalized chelator, antibody fragments could be radiofluorinated within 4 h at high specific activity. Here, we translated this method to preclinical PET imaging studies and showed feasibility of [(18)F]AlF-fluorinated hMN-14-Fab', [(18)F]AlF-hMN-14-Fab-AD2, and [(18)F]AlF-hMN-14-diabody for microPET imaging of CEA-expressing colonic cancer.

P3-02-02: Novel Ranpirnase-Based ImmunoRNases Display Potent Cytotoxicity in Diverse Human Breast Cancer Cell Lines

Ranpirnase (Rap) is an amphibian ribonuclease originally isolated from the oocytes of Rana pipiens. Rap shows anti-tumor activity in diverse cancers and its potency can be enhanced by chemically linking or recombinantly fusing Rap to a tumor-targeting antibody, as demonstrated for CD22- or CD74-expresing hematological malignancies, as well as a variety of Trop-2-expressing cell lines derived from breast, cervical, lung, pancreatic, and prostate cancers. The Dock-and-Lock (DNL) platform enables the design and generation of targetable therapeutics that are multivalent, multispecific, and multifunctional. Here, we report the successful application of the DNL method to generate a novel class of Rap-based immunoRNases, each of which features a pair of dimeric Rap molecules covalently tethered to a select monoclonal antibody at the carboxyl termini of the heavy chains. Two such constructs, designated E1-Rap and 22-Rap, were developed with hRS7 (humanized anti-Trop-2) and epratuzumab (humanized anti-CD22), respectively, purified to near homogeneity, and evaluated in a panel of human breast cancer lines, including the basal-like, triple-negative subtype (MDA-MB-468, MDA-MB-231, BT20, HCC1806, and HCC1395), the luminal B, HER2−negative subtype (MCF-7), and the HER2−positive subtype (SKBR3), all except HCC1395 expressing high to moderate levels of Trop-2, and none expressing CD22. As demonstrated by flow cytometry, E1-Rap and hRS7 bound equivalently to MDA-MB-468, indicating the affinity of E1-Rap for Trop-2 is not compromised. Surprisingly, 22-Rap, but not epratuzumab, also bound substantially to MDA-MB-468, albeit to a lesser extent than E1-Rap. We thus postulate that the four highly basic Rap molecules in the DNL conjugate may confer a spatial configuration to largely enhance their interaction with negatively-charged cell surface proteins, such as heparan sulfate proteoglycans. Whereas the individual DNL component (IgG or Rap) alone or in combination showed negligible in vitro cytotoxicity in all seven breast cancer cell lines examined, E1-Rap exhibited EC50 values of 1 nM or less in MDA-MB-468 (0.03 nM), MCF-7 (0.1 nM), BT20 (0.18 nM), HCC1806 (0.19 nM), and SKBR3 (1.29 nM). In comparison, the potency of 22-Rap was at least 10-fold lower than E1-Rap in MDA-MB-468, BT20 and HCC1806, with an EC50 of ∼2 nM. Neither E1-Rap nor 22-Rap was very effective in inhibiting the proliferation of the more aggressive MDA-MB-231, with an EC50 above 50 nM. In the Trop-2-negative HCC1395, the dose-response curves obtained for E1-Rap and 22-Rap were nearly identical (EC50 ∼100 nM), as they should be if the cytotoxicity was mediated mainly through the Rap component. The results of Immunofluorescence microscopy showed E1-Rap was effectively internalized and localized in the cytosol. Thus, these ImmunoRNases are potentially new cancer therapeutics for breast and other solid tumors.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-02-02.

[Effect of iron salts addition on the sensory characteristics of soy yogurt]

The soy-yogurt was used as food vehicle due to its therapeutic and nutritional properties and lower cost. The aim of this work was to develop an enriched soy-yogurt with 12 mg of elementary iron/l, with suitable sensory and technological properties. Four iron sources were tested: FeSO4.7H2O, NaFeEDTA, Ferrochel and microencapsulated FeSO4.7H2O. The products were evaluated by fermentation time, pH, titratable acidity, viscosity, consistency, iron concentration and sensory properties (difference from the control and acceptance tests). Viscosity and consistency data were submitted to analysis of variance and Tukey's test. Difference from the control data was evaluated by analysis of variance and Dunnett's test and the acceptance test was evaluated by analysis of variance and Tukey's test. For all iron salts used in the enrichment process, only the FeSO4.7H2O did not work out because of the undesirable sensorial characteristics of the final products. The others sources used in the enrichment process (NaFeEDTA, Ferrochel and microencapsulated FeSO4.7H2O) did not alter the fermentation time, titratable acidity and sensory and reologics properties of the soy-yogurt.

Effects of a novel fermented soy product on the serum lipids of hypercholesterolemic rabbits

OBJECTIVE

To assess the effect of a new feed soy product fermented by Enterococcus faecium and Lactobacillus jugurti on the serum lipid levels of rabbits with induced hypercholesterolemia.

METHODS

Thirty-two rabbits were divided into 4 groups as follows: 1) control (C); 2) hypercholesterolemic (H); 3) hypercholesterolemic + fermented product (HPF); and 4) control + fermented product (CPF). The H and HPF groups were fed with a diet with 0.15% (p/p) cholesterol in the first 15 days. C and CPF groups received regular food preparation. The HPF and CPF groups received 10 mL daily of the fermented 30 days. Blood samples were drawn at the beginning of the study and at the 15th and 30th days. Concentrations of total cholesterol, HDL-cholesterol, and triglycerides were analyzed.

RESULTS

After 15 days, the HPF group showed a total cholesterol concentration lower (18.4%) than that of the H group (p = 0.05), but this difference disappeared after 30 days. No change was observed in total cholesterol levels of C and CPF groups. After 15 days, the HDL-cholesterol was higher (17.8%) in the HPF group, but the triglyceride levels remained unchanged in all groups during the same period of time.

CONCLUSION

The soy fermented product caused an 18.4% reduction in total cholesterol and a 17.8% increase in the HDL-fraction. It may, therefore, be a possible coadjutor in the treatment of hypercholesterolemia.

Generation of a novel A kinase anchor protein and a myristoylated alanine-rich C kinase substrate-like analog from a single gene

A unique Drosophila gene encodes two novel signaling proteins. Drosophila A kinase anchor protein 200 (DAKAP200) (753 amino acids) binds regulatory subunits of protein kinase AII (PKAII) isoforms in vitro and in intact cells. The acidic DAKAP200 polypeptide (pI approximately 3.8) contains an optimal N-terminal myristoylation site and a positively charged domain that resembles the multifunctional phosphorylation site domain of vertebrate myristoylated alanine-rich C kinase substrate proteins. The 15-kilobase pair DAKAP200 gene contains six exons and encodes a second protein, DeltaDAKAP200. DeltaDAKAP200 is derived from DAKAP200 transcripts by excision of exon 5 (381 codons), which encodes the PKAII binding region and a Pro-rich sequence. DeltaDAKAP200 appears to be a myristoylated alanine-rich C kinase substrate analog. DAKAP200 and DeltaDAKAP200 are evident in vivo at all stages of Drosophila development. Thus, both proteins may play important physiological roles throughout the life span of the organism. Nevertheless, DAKAP200 gene expression is regulated. Maximal levels of DAKAP200 are detected in the pupal phase of development; DeltaDAKAP200 content is elevated 7-fold in adult head (brain) relative to other body parts. Enhancement or suppression of exon 5 excision during DAKAP200 pre-mRNA processing provides potential mechanisms for regulating anchoring of PKAII and targeting of cAMP signals to effector sites in cytoskeleton and/or organelles.

Characterization of the targeting, binding, and phosphorylation site domains of an A kinase anchor protein and a myristoylated alanine-rich C kinase substrate-like analog that are encoded by a single gene

A novel Drosophila A kinase anchor protein, Drosophila A kinase anchor protein 200 (DAKAP200), is predicted to be involved in routing, mediating, and integrating signals carried by cAMP, Ca(2+), and diacylglycerol (Li, Z., Rossi, E. A., Hoheisel, J. D., Kalderon, D., and Rubin, C. S. (1999) J. Biol. Chem. 274, 27191-27200). Experiments designed to assess this hypothesis now (a) establish the function, boundaries and identity of critical amino acids of the protein kinase AII (PKAII) tethering site of DAKAP200; (b) demonstrate that residues 119-148 mediate binding with Ca(2+)-calmodulin and F-actin; (c) show that a polybasic region of DAKAP200 is a substrate for protein kinase C; (d) reveal that phosphorylation of the polybasic domain regulates affinity for F-actin and Ca(2+)-calmodulin; and (e) indicate that DAKAP200 is myristoylated and that this modification promotes targeting of DAKAP200 to plasma membrane. DeltaDAKAP200, a second product of the DAKAP200 gene, cannot tether PKAII. However, DeltaDAKAP200 is myristoylated and contains a phosphorylation site domain that binds Ca(2+)-calmodulin and F-actin. An atypical amino acid composition, a high level of negative charge, exceptional thermostability, unusual hydrodynamic properties, properties of the phosphorylation site domain, and a calculated M(r) of 38,000 suggest that DeltaDAKAP200 is a new member of the myristoylated alanine-rich C kinase substrate protein family. DAKAP200 is a potentially mobile, chimeric A kinase anchor protein-myristoylated alanine-rich C kinase substrate protein that may facilitate localized reception and targeted transmission of signals carried by cAMP, Ca(2+), and diacylglycerol.

An intramembrane modulator of the ErbB2 receptor tyrosine kinase that potentiates neuregulin signaling

The ErbB2 receptor tyrosine kinase plays a critical role in a variety of developmental processes, and its aberrant activation may contribute to the progression of some breast and ovarian tumors. ASGP2, a transmembrane glycoprotein found on the surface of the highly metastatic ascites 13762 rat mammary adenocarcinoma cell line, is constitutively associated with ErbB2 in these cells and in mammary tissue from pregnant rats. Expression studies indicate that ASGP2 interacts directly and specifically with ErbB2 through one of its epidermal growth factor-like domains and that the co-expression of the two proteins in the same cell dramatically facilitates their direct stable interaction. Ectopic expression of ASGP2 in human melanoma tumor cells potentiates the response of endogenous ErbB2 to the neuregulin-1 growth factor. These observations point to a novel intramembrane mechanism for the modulation of receptor tyrosine kinase activity.

Sialomucin complex, a heterodimeric glycoprotein complex. Expression as a soluble, secretable form in lactating mammary gland and colon

Ascites 13762 rat mammary adenocarcinoma cells express abundantly on their cell surfaces a heterodimeric glycoprotein complex composed of a sialomucin ascites sialoglycoprotein (ASGP)-1 and a transmembrane subunit ASGP-2. The latter, which contains two epidermal growth factor-like domains, binds the receptor tyrosine kinase p185(neu), suggesting that the complex is bifunctional as well as heterodimeric. Immunoblot analyses using monoclonal antibodies prepared against the complex demonstrate high levels of expression in rat lactating mammary gland and colon. Immunolocalization studies with anti-ASGP-2 indicate that ASGP-2 is present in these two tissues in the apical regions of secretory epithelial cells. Both mammary gland and colon contain a soluble, secretable form of ASGP-2, which is not found in the ascites cells; milk and mammary gland also have the membrane form. Immunoblot analyses using a COOH-terminal-specific polyclonal antibody indicate that the soluble form of ASGP-2 is missing its COOH-terminal domains. Both the soluble and membrane forms of ASGP-2 are similar to the membrane-associated form from the 13762 adenocarcinoma with respect to Mr, antigenicity, and association with ASGP-1. The presence of ASGP-1 in milk suggests that it is a candidate for the uncharacterized high Mr milk mucin, MUCX. ASGP-2 expression is up-regulated in mammary gland during pregnancy, because it is undetectable in virgin and early pregnant rats but abundant in the gland from late pregnant and lactating animals. However, compared with the lactating mammary gland, the 13762 ascites cells overexpress ASGP-2 by more than 100-fold, which may contribute to their malignancy. These combined results indicate that sialomucin complex is a unique secreted product in the mammary gland and colon, whose behavior is different from that in the mammary ascites tumors, and which may play important roles in mammary and intestinal physiology.

Monoclonal antibodies specific to sailfish serum albumin: development of an assay for the identification of fish species in the field

Balb/c mice were immunized with albumin purified from sailfish (Istiophorus albicans) serum. Hybridomas were produced and screened by ELISA for reactivity with the purified albumins of sailfish, blue marlin (Makaira nigricans) and white marlin (Tetrapturus albidus). Monoclonal antibodies (MAbs) from 16 different clones exhibited activity against sailfish albumin. Thirteen of the MAbs showed cross-reactivity with the marlin species. Three MAbs exhibited distinct specificity for sailfish albumin. One of these species specific MAbs (M2D1) was conjugated to horseradish peroxidase (HRP) in order to construct an ELISA for identification of sailfish from serum. The ELISA for sailfish correctly identified eight sailfish from 26 billfish serum samples. The MAb-peroxidase conjugate was highly specific toward sailfish in that no reaction against heterologous species was detected.