Insulin‐like growth factor‐1 receptor as a novel prognostic marker and its implication as a cotarget in the treatment of human adenocarcinoma of the esophagus

Insulin‐like growth factor‐1 receptor (IGF‐1R) and human epidermal growth factor receptor‐2 (HER2) receptor expression has been found to be a key regulator of tumorigenesis. The purpose of our study was to establish the prognostic significance of IGF‐1R in esophageal cancer and to determine the effect of IGF‐1R and HER2 targeting with α‐IR3 and Herceptin? antibodies on the proliferation of esophageal cancer cells in vitro. IGF‐1R expression and clinicopathological correlations were analyzed with a tissue microarray containing 234 esophageal cancer specimens (133 adenocarcinomas and 101 squamous cell carcinomas). Proliferation changes associated with Herceptin? and α‐IR3 blockage were evaluated with the unique human esophageal cancer cell lines Pt1590 and LN1590. IGF‐1R and HER2 expression levels, activation and phosphorylation status of downstream signaling proteins involved in the activation pathways were analyzed by Western blotting. IGF‐1R overexpression was detected in 121 (52%) of the 234 esophageal tumors examined. In the subgroup of 87 HER2‐positive tumors, 93.1% showed concordant overexpression for IGF‐1R. IGF‐1R was identified as a variable associated with reduced overall survival for adenocarcinoma (p = 0.05), but not for squamous cell carcinoma. The combination of Herceptin? and α‐IR3 was more effective in inhibiting in vitro proliferation than treatment with either agent alone (p < 0.01). This was associated with a decrease in HER2 and IGF‐1R protein levels and suppression of Akt‐ and MAP kinase phosphorylation. IGF‐1R expression can be used as a novel prognostic marker for adenocarcinomas of the esophagus. Cotreatment with IGF‐1R and HER2 antibodies might become a valuable and effective treatment option in esophageal adenocarcinoma.     

Cooperative enhancement of F-cell formation in baboons treated with erythropoietin and hydroxyurea

Chronically anemic baboons on a continuous hydroxyurea regimen were treated with pulsed doses of recombinant human erythropoietin (rHuEpo) to test whether the combination of these two compounds, which individually induce F-cell production, can enhance further F-cell output. A low-F-cell-responding animal under chronic hydroxyurea treatment was given three separate pulses of Epo and responded with F- reticulocyte increments that were similar to the sum increments caused by either hydroxyurea alone or rHuEpo alone. The same results were obtained in a high-F-responding animal similarly treated. These findings suggest that rHuEpo and hydroxyurea can increase F cell numbers in an additive fashion. It is speculated that both compounds act through perturbation of erythroid differentiation kinetics.     

Lack of a co-promoting effect of a 60 Hz magnetic field on skin tumorigenesis in SENCAR mice

It has been proposed that extremely low frequency (ELF) magnetic fields may enhance tumorigenesis through a co-promotional mechanism. This hypothesis has been further tested using the two-stage model of mouse skin carcinogenesis, i.e. 12-O-tetradecanoylphorbol-13-acetate (TPA)- induced promotion of skin tumors in mice initiated by a single subcarcinogenic dose of 7,12-dimethylbenz[a]anthracene. Experimentation described herein utilized the SENCAR mouse and examined the effect of a magnetic field on skin tumor promotion induced by three different doses of TPA within its dose-response range, i.e. 0.85, 1.70 or 3.40 nmol, administered twice per week. SENCAR mice (56/treatment group) were exposed to a 60 Hz magnetic field having a flux density of 2 mT for 6 h/day for 5 days/week and compared with mice exposed to the ambient magnetic field. Tumor incidence and multiplicity were monitored weekly for 23 weeks of TPA promotion. Statistical evaluation of the effects of the magnetic field on tumor incidence and multiplicity did not reveal any statistically significant effects; thus, within the sensitivity limits imposed by the animal model and the exposure parameters employed, no promotional or co-promotional effect of a 2 mT magnetic field on skin tumor development in SENCAR mice could be demonstrated.      

Colonic wall thickness, pancreatic enzyme dose and type of preparation in cystic fibrosis

Increased colonic wall thickness has been reported in patients exposed to large doses of high strength pancreatic enzyme preparations who did not develop fibrosing colonopathy. This has been interpreted as evidence for a spectrum of subclinical disease. The relation between sonographically measured colonic wall thickness and pancreatic enzyme preparation and dose was studied in 86 children with cystic fibrosis (CF). Colonic wall thickness of a control group was also measured. The average thickness in all colonic regions was higher in the CF group (overall average range 0.7-2.5 mm v 0.6-1.4 mm in the control group). There was no significant relation between colonic wall thickness and age, sex, total dose of lipase, or copolymer. Apart from one patient with an early colonic stricture, none of those exposed to high doses of lipase, or the methacrylic acid copolymer Eudragit L30 D55, showed evidence of subclinical damage to the colon. The reproducibility of the sonographic measurements was poor.     

Radical Redo Surgery for Local Rectal Cancer Recurrence Improves Overall Survival: A Single Center Experience

Background  To date, the survival benefit of redo surgery in locally recurrent rectal adenocarcinoma remains unclear. Study Design  In an institutional study, operations for recurrence were retrospectively analyzed. Survival was calculated using the Kaplan–Meier plot and Cox regression analysis. Results  A total of 72 patients with local recurrence were explored or resected. In 38 patients, there was synchronous distant organ recurrence. Forty-five of 72 were re-resected and in 37 of 45 cases, R0 situations were achieved. In 11 of 38 metastasized patients, both local and distant organ recurrence were successfully removed. For obtaining tumor control, resections of inner genitals, bladder, and sacral bone were necessary in 10, 4, and 11 patients, respectively. Survival was better for patients re-resected with a median overall survival of 54.9 months, as compared with 31.1 months among non-resected patients (p = 0.0047, log-rank test). Subgroup analysis revealed that a benefit of re-resection was observed to a lesser extent in synchronous local and in distant disease. Cox analysis showed that initial Dukes stage and complete resections of local recurrences were independently determining prognosis (relative risk 1.762 and 0.689, p = 0.008 and p = 0.002, respectively). Conclusions  Radical surgery for local recurrence can improve survival if complete tumor clearance is achieved, and concomitant distant tumor load should not principally preclude re-resection.     

Sequence analysis of the coding region of human methionine synthase: relevance to hyperhomocysteinaemia in neural-tube defects and vascular disease

Elevated homocysteine (Hcy) levels are observed in two apparently unrelated diseases: neural-tube defects (NTD) and premature vascular disease. Defective human methionine synthase (MS) could result in elevated Hcy levels. We sequenced the coding region of MS in 8 hyperhomocysteinaemic patients (4 NTD patients and 4 patients with pregnancies complicated by spiral arterial disease, SAD). We identified only one mutation resulting in an amino acid substitution: an A-->G transition at bp 2756, converting an aspartic acid (D919) into a glycine (G). We screened genomic DNA for the presence of this mutation in 56 NTD patients, 69 mothers of children with NTD, 108 SAD patients and 364 controls. There was no increased prevalence of the GG and AG genotypes in NTD patients, their mothers or SAD patients. The D919G mutation does not seem to be a risk factor for NTD or vascular disease. We then examined the mean Hcy levels for each MS genotype. There was no correlation between GG- or AG-genotype and Hcy levels. The D919G mutation is thus a fairly prevalent, and probably benign polymorphism. This study, though limited, provides no evidence for a major involvement of MS in the aetiology of homocysteine-related diseases such as NTD or vascular disease.      

The functional expression of tissue factor by fibroblasts and endothelial cells under flow conditions

The expression of tissue factor (TF) by a variety of vascular cell types under physiologic flow conditions is critical to factor X activation and in vivo clotting. Therefore, in a parallel-plate flow chamber (volume 40 microL) we mounted monolayers of human embryonic fibroblasts (FBs) or interleukin-1 alpha (IL-1 alpha) (5 U/mL x 4 hours)-stimulated human umbilical vein endothelial cells (ECs). Inflow buffer contained 10 nmol/L factor VIIa, 100 nmol/L factor X, and 2.0 mmol/L CaCl. With FBs, production of factor Xa (product of outflow concentration of factor Xa-and flow rate) increased 200-fold over the range of shear stress from 0 to 2.7 dynes/cm2. Production values (mean +/- SE (N)) were 7.93 +/- 0.024 (6), 312 +/- 7.3 (6), 688 +/- 33.1 (8), 1,033 +/- 119 (6), and 1,601 +/- 183 (7) fmol/cm2.minute at shear stresses of 0, 0.27, 0.68, 1.35, and 2.7 dynes/cm2, respectively. Further experiments at 0.68 dynes/cm2 indicated that factor Xa production increased with factor X concentration over the range from 3 to 100 nmol/L, but changed little from 300 to 1,000 nmol/L. With ECs, production was 0.13 +/- 0.86 (6), 8.17 +/- 1.65 (13), and 1.66 +/- 1.66 (5) fmol/cm2.minute at 0, 0.68, and 2.7 dynes/cm2, respectively. However, in the presence of an antibody directed against tissue factor pathway inhibitor (TFPI) production with ECs was augmented to 16.46 +/- 0.80 (8), 149.8 +/- 18.6 (8), and 48.9 +/- 10.3 (10), respectively, at these same shear stresses. Control experiments with factor VIIa, factor X, or both absent confirm for both cell types the specificity of the reaction for the TF pathway. Similarly, specificity for TF itself is shown by the virtual absence of factor Xa generation in the presence of the monoclonal antibody HTF1-7B8 directed against human TF. We conclude that ECs, even when activated, are normally unable to generate significant quantities of factor Xa in the presence of factors X and VIIa. However, significant quantities of factor Xa are possible in the presence of an inhibitor of TFPI. On the other hand, production of factor Xa by fibroblasts is markedly augmented by shear stress, yet independent of the availability of substrate factor X above an inflow concentration of 100 nmol/L. The latter suggests a direct effect of flow on the fibroblast monolayers, not substrate limitation by convective diffusion.     

The effect of X chromosome inactivation on the inhibition of Plasmodium falciparum malaria growth by glucose-6-phosphate-dehydrogenase- deficient red cells

Previous data on in vitro culture of Plasmodium falciparum malaria demonstrated that red cell glucose-6-phosphate dehydrogenase deficiency (G6PD-) inhibited parasite growth in deficient hemizygous males. This study investigated the effect of heterozygosity for G6PD- on parasite growth. Blood was obtained from 8 female Sardinian G6PD- heterozygotes with G6PD normal cells ranging from 13% to 60%. For comparison, blood from a G6PD- hemizygous male, containing 100% deficient red cells, was mixed in different proportions with compatible normal blood. In both experiments, parasite growth was inhibited by the presence of deficient cells. In both cases, it was found that the inhibition could be explained by a simple dilution of normal cells by G6PD- cells. Thus, the typical female heterozygote is also protected to a significant extent. When considering the "malaria hypothesis" as it relates to G6PD, protection of the female heterozygote as well as the male hemizygote must be taken into account.     

Partial purification and characterization of a growth factor for macrophage progenitor cells with high proliferative potential in mouse bone marrow

A population of macrophage progenitor cells, with high proliferative potential, has recently been demonstrated in postfluorouracil-treated and normal mouse bone marrow (BM) in vitro, when the newly discovered growth factor (synergistic activity, SA) is combined with a macrophage colony-stimulating factor (CSF) as a proliferative stimulus. SA, shown to be present in human spleen and placental conditioned media (HSCM and HPCM, respectively) have been studied and found to be unstable to trypsin digestion and to heating at 50 degrees C or above; stable between pH 4 and 9; nonadherent to Con-A-Sepharose; and to have an isoelectric point between pH 5 and 5.8 and a molecular weight of between 14,000 and 21,000 as indicated by gel filtration chromatography. SAs from both HSCM and HPCM have been purified 89- and 122-fold, respectively, by precipitation of extraneous proteins at pH 5 followed by chromatographing twice on Sephacryl S200. Neither of these partially purified SAs contain any CSF for mouse BM. These results indicate that the SAs from HSCM and HPCM may be closely related and that they are structurally different from CSFs derived from various murine sources that have been shown to be stable to proteolytic enzymes and heat.     

Distinct ongoing Ig heavy chain rearrangement processes in childhood B- precursor acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is thought to arise from the clonal expansion of a single transformed precursor cell. However, an oligoclonal Ig heavy chain (IgH) rearrangement pattern has been observed in 30% of ALL patients and was shown to be the result of ongoing rearrangement events. The extent and nature of these ongoing rearrangement processes in individual patients has so far remained obscure. We performed a detailed analysis of leukemic VHDJH rearrangements in three children with B-precursor ALL at diagnosis and one B-lymphoid blast crisis of a child with Ph+ chronic myeloid leukemia at diagnosis and relapse. The children were selected because they presented with multiple IgH rearrangements on Southern blot analysis. Polymerase chain reaction analysis of leukemic cells from two B-precursor ALL patients showed exclusively two groups of related sequences resulting from VH gene replacement events. Most VH gene replacements involved 3' located acceptor VH genes. Analysis of cells from the other B-precursor ALL patient showed exclusively related sequences as a result of VH gene joinings to a pre-existing DJH rearrangement. In the B-lymphoid blast crisis, a single germline precursor cell had generated multiple unrelated rearrangements and additional groups of related rearrangements resulting from VH to DJH joinings. Direct proof for the VH to DJH joining mechanism was obtained by amplification of the expected preexisting DJH rearrangements. Our findings suggest that the pattern of ongoing rearrangements in an individual patient reflects the IgH rearrangement status of the precursor cell at the time of malignant transformation. Sequence analysis of VHDJH rearrangements at diagnosis may therefore allow a prediction of the reliability of complementarity determining region 3 probes for the detection of minimal residual disease.