Large-scale molecular and tissue microarray analysis of mesothelin expression in common human carcinomas

The 40-kilodalton processed glycoprotein, mesothelin, is highly expressed in epithelial mesotheliomas and adenocarcinomas of the ovary (serous papillary) and pancreas, but its expression in a large series of other common carcinomas has not been completely explored. In the present study, we used oligonucleotide and tissue microarrays to profile the expression of the mesothelin gene (MSLN) and encoded protein, respectively. Among 150 carcinomas of multiple anatomic sites, we found the highest average expression of MSLN in serous carcinomas of the ovary and adenocarcinomas of the pancreas, consistent with previous reports, as well as measurable but less-striking expression in pulmonary, gastric/esophageal, and colorectal adenocarcinomas. On tissue microarrays containing 621 carcinomas derived from the same and additional sites as those profiled by gene expression, mesothelin immunoreactivity was highest in cancers of the ovary (serous papillary, endometrioid, and undifferentiated) and pancreas, with less frequent staining seen in adenocarcinomas of the endometrium, lung, and stomach/esophagus. Some immunopositivity was observed in 42% of pulmonary adenocarcinomas, including 18% that had >50% of tumor cells that were immunoreactive. Some 14% of breast and 30% of colorectal adenocarcinomas showed immunopositivity, but no case contained >50% tumor cells that were immunoreactive. Mesothelin was either entirely absent or present in <5% of carcinomas of the prostate, bladder/ureter, liver, kidney, and thyroid. Overall, we observed good concordance between the results obtained by oligonucleotide and tissue microarrays. This large study of the MSLN gene and protein expression in common carcinomas provides data for future investigations that evaluate the utility of mesothelin/megakaryocyte potentiating factor as a potential serum tumor marker or target of immunotoxin-based therapy in human cancers.     

Functional evidence of decreased tumorigenicity associated with monochromosome transfer of chromosome 14 in esophageal cancer and the mapping of tumor-suppressive regions to 14q32

Despite the abundant evidence of high allelic loss of chromosome arm 14q in human cancers, tumor-suppressor genes mapped to this chromosome have yet to be identified. To narrow the search for candidate genes, we performed monochromosome transfer of chromosome 14 into an esophageal carcinoma cell line, SLMT-1 S1. Statistically significant suppression of the tumorigenic potential of microcell hybrids containing the transferred chromosome 14 provided functional evidence that tumor-suppressive regions of chromosome 14 are essential for esophageal cancer. Tumor segregants emerging in nude mice during the tumorigenicity assay were analyzed by detailed PCR-microsatellite typing to identify critical nonrandomly eliminated regions (CRs). A 680-kb CR mapped to 14q32.13 and an approximately 2.2-Mb CR mapped to 14q32.33 were delineated. Dual-color BAC FISH analysis of microcell hybrids and tumor segregants verified the selective loss of the 14q32.13 region. In contrast, similar transfers of an intact chromosome 11 into SLMT-1 S1 did not significantly suppress tumor formation. These functional complementation studies showing the correlation of tumorigenic potential with critical regions of chromosome 14 validated the importance of the 14q32 region in tumor suppression in esophageal cancer. The present study also paved the path for further identification of novel tumor-suppressor genes that are relevant to the molecular pathogenesis of esophageal cancer.     

Reconstitution of T- and B-cell function after T-lymphocyte-depleted haploidentical bone marrow transplantation in severe combined immunodeficiency due to adenosine deaminase deficiency

A 4-month-old male received a T-lymphocyte-depleted haploidentical bone marrow transplant (BMT) for correction of severe combined immunodeficiency (SCID) due to adenosine deaminase (ADA) deficiency. Although previous haploidentical bone marrow transplants have been attempted in ADA-deficient SCID, complete reconstitution of both B-lymphocyte and T-lymphocyte function has not been obtained after a single transplant. In this patient, however, rapid, complete, and persistent engraftment occurred. Potential reasons for this successful reconstitution include the use of ablation by chemotherapy (busulfan, cyclophosphamide, and cytosine arabinoside), the in vitro technique of using monoclonal antibody (CT-2) and complement to deplete the donor cells of T lymphocytes, and the relative good health of the patient prior to the transplant. Further trials using this method of haploidentical BMT may prove it to be a successful method of immunologic reconstitution in ADA-deficient SCID patients for whom an HLA-identical marrow is not available.     

Identification of two mutations in a compound heterozygous child with dihydrolipoamide dehydrogenase deficiency

An infant girl with elevated blood lactate, pyruvate, and plasma branched-chain amino acids was diagnosed with dihydrolipoamide dehydrogenase (E3; dihydrolipoamide: NAD+ oxidoreductase, EC 1.8.1.4) deficiency. Activities of the pyruvate dehydrogenase complex and E3 from patient were 26 and 2% of controls in blood lymphocytes, and 11 and 14% in cultured skin fibroblasts, respectively. Western blot analysis demonstrated that the amount of E3 protein in fibroblasts from the patient and her father was about half of controls, while Northern blot analysis showed normal amounts of E3 RNA. DNA sequencing of cloned full-length E3 cDNAs from the patient revealed two mutations in separate alleles. One is a single base insertion of an extra adenine in the last codon of the leader peptide sequence (TAC-->TAAC) leading to a nonsense mutation which results in the premature termination of the precursor E3 polypeptide (Y35X). The other is a missense mutation due to substitution of guanine for adenine, causing an Arg-->Gly substitution at amino acid 460 of the mature protein (R460G) which triggers the loss of E3 activity probably by structural change in the E3 dimer. DNA sequencing of E3 cDNAs from the parents demonstrated that the nonsense mutation was inherited from the father and the missense mutation was inherited from the mother.      

Synergistic effect of gelatin microspheres incorporating TGF-beta1 and a physical barrier for fibrous tissue infiltration on skull bone formation

The objective of this study is to examine whether or not bone formation at a skull bone defect induced by gelatin microspheres incorporating transforming growth factor (TGF)-beta1 is promoted by prevention of fibrous tissues into the defect. The 6-mm diameter bone defect of rabbit skulls was applied with gelatin microspheres incorporating TGF-beta1 or free TGF-beta1 and physically covered by a barrier membrane. When the bone formation at the defect was assessed 6 weeks postoperatively, combinational application of gelatin microspheres incorporating 0.1 microg of TGF-beta1 with the barrier membrane induced bone formation at the skull defect, in marked contrast to that of 0.1 microg of free TGF-beta1 and empty gelatin microspheres. Complete defect closure was histologically observed by the newly formed bone tissue. Without the barrier membrane, gelatin microspheres incorporating TGF-beta1 were less effective in inducing bone formation, whereas free TGF-beta1 and empty gelatin microspheres were ineffective. The skull defect was occupied by fibrous tissue infiltrated in place of bone tissue. The bone mineral density at the skull defect applied with gelatin microspheres incorporating TGF-beta1 plus the membrane was significantly higher than that of gelatin microspheres incorporating TGF-beta1 alone. The present data indicated that physical protection from the soft tissue infiltration enabled gelatin microspheres incorporating TGF-beta1 to synergistically enhance the osteoinductive ability at the skull defect.     

Reconstitution of T-cell deficiency by thymic hormone or thymus transplantation therapy

Correction of T-cell defects by either thymic hormone treatment or thymus transplantation has proven to be more difficult clinically than historically anticipated. Because the precise action of thymic hormones is unknown and because these hormones act upon post-thymic cells, therapeutic attempts may fail owing to lack of sufficient substrate population. Results of thymic transplantation suggest that this procedure may be best utilized for the treatment of mild T-cell defects, rather than as complete replacement treatment for severe deficiency. Future clinical trials of thymic transplantation or thymic hormone appear justified in narrowly circumscribed and well-characterized conditions.     

Henricine, a New Tetrahydrofuran Lignan from Schisandra henryi

A new tetrahydrofuran lignan, named henricine ( 1), was isolated from the stems of SCHISANDRA HENRYI. High resolution COSY spectrum was used in the structural elucidation.