Sirolimus and mycophenolate mofetil as GVHD prophylaxis in myeloablative, matched-related donor hematopoietic cell transplantation

We investigated sirolimus and mycophenolate mofetil (MMF) as graft-versus-host disease (GVHD) prophylaxis in patients with advanced hematologic malignancies receiving myeloablative hematopoietic cell transplantation (HCT) from HLA-identical sibling donors. Based on pre-study stopping rules, the trial was closed to accrual after enrollment of 11 adult patients. Seven of the 11 patients received busulfan-containing preparative regimens. Sirolimus was discontinued in 3 patients due to toxicity-related events of severe sinusoidal obstructive syndrome, portal vein thrombosis, altered mental status and in 1 patient due to risk of poor wound healing. Six of the 11 patients developed grade II-IV acute GVHD (AGVHD) a median of 15.5 days post-HCT. Two of 3 patients with grade IV AGVHD had sirolimus discontinued by 9 days post-HCT. All patients responded to AGVHD therapy without GVHD-related deaths. There were 2 nonrelapse- and 2 relapse-related deaths. At a median follow-up of 38 months (2–47 months), 7 of 11 patients were alive without disease. MMF and sirolimus GVHD prophylaxis did not reduce the risk of acute GVHD, however, there were no GVHD-related deaths. The severe toxicities in the patients receiving the busulfan-containing preparative regimens limited the continued use of sirolimus and MMF for the prevention of AGVHD.

H-Y antibody titers are increased in unexplained secondary recurrent miscarriage patients and associated with low male : female ratio in subsequent live births

BACKGROUND

The birth of a boy is significantly more common than a girl prior to secondary recurrent miscarriage (SRM) and is associated with a poorer chance of a subsequent live birth. Children born after SRM are more likely to be girls. High-titer antisera specific for male antigens (H-Y) have been shown to arrest development of male bovine embryos efficiently. We consequently questioned the role of H-Y antibodies in women with SRM.

METHODS

Serum samples from patients with unexplained SRM (n = 84), unexplained primary recurrent miscarriage (PRM) (n = 12) and healthy women (n = 37) were obtained. The samples were taken during pregnancy (gestational weeks 4-5) for 77 (80%) of the patients. Enzyme-linked immunosorbent assay was used to detect immunoglobulin G antibodies that specifically recognized any of the five recombinant H-Y proteins (EIF1AY, RPS4Y1, ZFY, DDX3Y and UTY) and their H-X homologs.

RESULTS

H-Y-specific antibodies were more frequent in SRM patients (46%) compared with female controls (19%, P = 0.004) and PRM patients (8%, P = 0.01). The presence of H-Y antibodies in early pregnancy was associated with a low male: female birth ratio among the subsequent live births, as only 12% of children born to H-Y antibody-positive patients were boys compared with 44% boys born to H-Y antibody negative patients (P = 0.03).

CONCLUSIONS

The high frequency of H-Y antibody-positive SRM patients and the association between the presence of these antibodies in early pregnancy and the low number of male offspring, suggest that maternal immune responses against H-Y antigens can cause pregnancy losses. Further exploring these mechanisms may increase our understanding of unexplained SRM.

Long-term outcomes of high-dose therapy using busulfan, etoposide, and cyclophosphamide followed by allogeneic hematopoietic cell transplantation for patients with high-risk or advanced stages of myeloid malignancies

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Patients (pts) with high risk (HR) or advanced myeloid malignancies have limited effective treatment options. These include high-dose therapy followed by allogeneic hematopoietic cell transplantation (HCT). We report a single institution long-term follow-up of 96 pts, median age 50 (20–60) yrs, who received HLA matched related HCT between 1992 and 2007. All pts were treated with a uniform preparatory regimen: busulfan 16.0 mg/kg (d-8 to-5), etoposide 60mg/kg (d-4), cyclophosphamide 60mg/kg (d-2), and graft-versus-host-disease (GVHD) prophylaxis of cyclosporine and prednisone. Disease status at transplantation was induction failure (IF) acute myeloid leukemia (AML) (n = 10), HR AML in 1st complete remission (CR1) n = 11, in CR2 (n = 5), in CR3 (n = 2), relapsed refractory (RR) AML (n = 14), chronic myeloid leukemia (CML) in second chronic phase (n = 6), blast crisis (n = 2), myelofibrosis (n = 6), myeloproliferative disorders (n = 2), and MDS (n = 38). Thirty-six % (n = 35) of pts received bone marrow while 64 % (n = 61) received G-CSF mobilized peripheral blood mononuclear cells (PBMC). With a median follow up of 5.6 yrs (1.6–14.6 yrs) actuarial 5-year overall survival (OS) was 32% (95% CI 22–42%) and 5-year probability for freedom from progression (FFP) was 64% (95% CI 52%-76%). Relapse rate was 32% at 1 year and remained at 36% (95%CI 24%-48%) at 2 and 5 years with no further increase in relapse beyond two years. Non-relapse mortality (NRM) was 29 % (95% CI 20%5–38%) at day 100 and 39% (95% CI 29%-49%) at one yr. Cumulative incidence of acute (grade 3–4) and chronic GVHD was 28% (95% CI 19%-37%) and 38% (95% CI 24%-52%), respectively. There was no statistically significant difference in OS; 31% versus 32% (p = 0.89) or FFP 71% versus 60% (p = 0.29) for recipients of BM versus PBMC with similar results in IF and RR AML. These results confirm that pts with high-risk or advanced myeloid malignancies can achieve long-term survival following myeloablative allogeneic HCT with aggressive conditioning. Relapse and acute GVHD remain significant causes of mortality. Strategies to augment graft-versus-tumor reactions and reduce GVHD remain essential for improving long-term outcomes.

No significant financial relationships to disclose.

Bis(2,2'-bipyridine)(dicyanamido)copper(II) tetrafluoroborate

In the title compound, [Cu(C(2)N(3))(C(10)H(8)N(2))(2)]BF(4), the Cu(II) atom shows distorted trigonal-bipyramidal geometry, with the dicyanamido ligand in the equatorial plane. The two out-of-plane Cu-N bond lengths to bipyridine are 2.006 (3) and 1.998 (3) A, whereas the in-plane Cu-N distances are 2.142 (3) and 2.043 (3) A to the bipyridine, and 2.015 (3) A to the dicyanamide.

Induction of GADD45 and JNK/SAPK-dependent apoptosis following inducible expression of BRCA1

The breast cancer susceptibility gene BRCA1 encodes a protein implicated in the cellular response to DNA damage, with postulated roles in homologous recombination as well as transcriptional regulation. To identify downstream target genes, we established cell lines with tightly regulated inducible expression of BRCA1. High-density oligonucleotide arrays were used to analyze gene expression profiles at various times following BRCA1 induction. A major BRCA1 target is the DNA damage-responsive gene GADD45. Induction of BRCA1 triggers apoptosis through activation of c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK), a signaling pathway potentially linked to GADD45 gene family members. The p53-independent induction of GADD45 by BRCA1 and its activation of JNK/SAPK suggest a pathway for BRCA1-induced apoptosis.

MIP1, a new yeast gene homologous to the rat mitochondrial intermediate peptidase gene, is required for oxidative metabolism in Saccharomyces cerevisiae

Cleavage of amino-terminal octapeptides, F/L/IXXS/T/GXXXX, by mitochondrial intermediate peptidase (MIP) is typical of many mitochondrial precursor proteins imported to the matrix and the inner membrane. We previously described the molecular characterization of rat liver MIP (RMIP) and indicated a putative homolog in the sequence predicted from gene YCL57w of yeast chromosome III. A new yeast gene, MIP1, has now been isolated by screening a Saccharomyces cerevisiae genomic library with an RMIP cDNA probe. MIP1 predicts a protein of 772 amino acids (YMIP), which is 54% similar and 31% identical to RMIP and includes a putative 37-residue mitochondrial leader peptide. RMIP and YMIP contain the sequence LFHEMGHAM HSMLGRT, which includes a zinc-binding motif, HEXXH, while the predicted YCL57w protein contains a comparable sequence with a lower degree of homology. No obvious biochemical phenotype was observed in a chromosomally disrupted ycl57w mutant. In contrast, a mip1 mutant was unable to grow on nonfermentable substrates, while a mip1 ycl57w double disruption did not result in a more severe phenotype. The mip1 mutant exhibited defects of complexes III and IV of the respiratory chain, caused by failure to carry out the second MIP-catalyzed cleavage of the nuclear-encoded precursors for cytochrome oxidase subunit IV (CoxIV) and the iron-sulfur protein (Fe-S) of the bc1 complex to mature proteins. In vivo, intermediate-size CoxIV was accumulated in the mitochondrial matrix, while intermediate-size Fe-S was targeted to the inner membrane. Moreover, mip1 mitochondrial fractions failed to carry out maturation of the human ornithine transcarbamylase intermediate (iOTC), specifically cleaved by RMIP. A CEN plasmid-encoded YMIP protein restored normal MIP activity along with respiratory competence. Thus, YMIP is a functional homolog of RMIP and represents a new component of the yeast mitochondrial import machinery.

Primary structure and function of a second essential member of the heterooligomeric TCP1 chaperonin complex of yeast, TCP1 beta

A role for heterooligomeric TCP1 complex as a chaperonin in the eukaryotic cytosol has recently been suggested both by structural similarities with other chaperonins and by in vitro experiments showing it to mediate ATP-dependent folding of actin, tubulin, and luciferase. Here we present the primary structure of a second subunit of the complex and present genetic and functional analyses. The TCP1 beta amino acid sequence, predicted from the cloned gene, bears 35% identity to TCP1, termed here TCP1 alpha, containing the same highly conserved residues found in the collective sequence of chaperonins. The predicted product was identified as the fastest-migrating species of the TCP1 complex purified from soluble extracts of yeast. The TCP1 beta gene, like TCP1 alpha, is essential. Strains containing lethal disruptions of either gene could not be rescued by additional copies of the other. Spores bearing disruption of either gene germinated as single, large-budded cells. Similarly, large-budded cells were observed following shift to 37 degrees C of strains carrying temperature-sensitive mutations in either TCP1 alpha or TCP1 beta. The arrested cells contained replicated DNA present in single nuclear masses, associated with abnormal tubulin staining patterns, supporting the assertion that mitotic spindle formation and function are impaired. We conclude that TCP1 beta supplies an essential function that partially overlaps with that of TCP1 alpha in acting as a molecular chaperone in tubulin and spindle biogenesis.

TCP1 complex is a molecular chaperone in tubulin biogenesis

A role in folding of newly translated proteins in the cytosol of eukaryotes has been proposed for t-complex polypeptide-1 (TCP1), although its molecular targets have not yet been identified. Tubulin is a major cytosolic protein whose assembly into microtubules is critical to many cellular processes. Although numerous studies have focused on the expression of tubulin, little is known about the processes whereby newly translated tubulin subunits acquire conformations that enable them to form alpha-beta-heterodimers. We examined the biogenesis of alpha- and beta-tubulin in rabbit reticulocyte lysate, and report here that newly translated tubulin subunits entered a 900K complex in a protease-sensitive conformation. Addition of Mg-ATP, but not nonhydrolysable analogues, released the tubulin subunits as assembly-competent protein with a conformation that was relatively protease-resistant. The 900K complex purified from reticulocyte lysate contained as its major constituent a 58K protein that cross-reacted with a monoclonal antiserum against mouse TCP1. We conclude that TCP1 functions as a cytosolic chaperone in the biogenesis of tubulin.