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cDNA Expression Library (cdna + expression_library)
Selected AbstractsMultiple serological biomarkers for colorectal cancer detectionINTERNATIONAL JOURNAL OF CANCER, Issue 7 2010Chung-Chuan Chan Abstract The aim of this study was to initiate a survey of human autoantibody responses to a panel of select colorectal tumor-associated antigens identified by previous serological analysis of a cDNA expression library and to subsequently identify multiple serological biomarkers for the detection of colorectal cancer. For screening of autoantibodies against colorectal tumor-associated antigens, sera from 94 colorectal cancer patients and 54 normal controls were analyzed by enzyme-linked immunosorbent assay using recombinant rCCCAP, rHDAC5, rP53, rNMDAR and rNY-CO-16 proteins as coating antigens. Seropositivity among colorectal cancer patients to the 5 individual coating antigens varied from 18.1% to 35.1%. Seropositivity to any of the 5 coating antigens was 58.5% and combining this analysis with evaluation of serum carcinoembryonic antigen (,5 ng/ml) significantly increased the seropositivity to 77.6%. Seropositivity of early-stage (Dukes' Stages A and B) colorectal cancer patients to CEA was 21.9%, and seropositivity to any of the 5 colorectal cancer-associated antigens was 53.7%, and the combination of these 2 measurements resulted in a higher diagnostic capacity (65.9%) than either marker alone. In conclusion, these results collectively indicated that combined detection of serum autoantibody profiles against our panel of colorectal tumor-associated antigens and the analysis of carcinoembryonic antigen provides a promising diagnostic biomarker for colorectal cancer, particularly among early-stage patients. [source] Receptor for the globular heads of C1q (gC1q-R, p33, hyaluronan-binding protein) is preferentially expressed by adenocarcinoma cellsINTERNATIONAL JOURNAL OF CANCER, Issue 5 2004Daniel B. Rubinstein Abstract Combinatorial Ig libraries with phage display allow in vitro generation of human Ig fragments without the need to maintain hybridomas in ongoing cell culture or to select circulating Ig from human serum. Identifying tumor-associated antigens on the surface of intact tumor cells, as opposed to purified proteins, presents a challenge due to the difficulty of preserving complex 3-D epitopic sites on the cell surface, the variable expression of antigens on different malignant cell types and the stereotactic interference of closely associated proteins on the intact membrane surface limiting accessibility to antigenic sites. A combinatorial Ig library of 1010 clones was generated from the cDNA of PBMCs derived from patients with breast adenocarcinoma. Following subtractive panning, the library was enriched for Ig (Fab fragment) binding to intact adenocarcinoma cells and the resultant Fabs were screened against a cDNA expression library, itself generated from breast cancer cells. Using this approach, we isolated clones from the cDNA library expressing gC1q-R, a glycoprotein comprising the major structure of C1, the first component of the complement system. gC1q-R is a 33 kDa glycoprotein expressed not only on the cell surface but also intracellularly, with motifs that target it to mitochondria and complete homology with HABP and human HeLa cell protein p32, which is copurified with pre-mRNA SF2. Sequencing of the gene encoding tumor-associated gC1q-R did not reveal any consistent tumor-specific mutations. However, histochemical staining with anti-gC1q-R MAb demonstrated marked differential expression of gC1q-R in thyroid, colon, pancreatic, gastric, esophageal and lung adenocarcinomas compared to their nonmalignant histologic counterparts. In contrast, differential expression was not seen in endometrial, renal and prostate carcinomas. Despite high expression in breast carcinoma, gC1q-R was also expressed in nonmalignant breast tissue. Although the precise relation of gC1q-R to carcinogenesis remains unclear, our finding of tumor overexpression and the known multivalent binding of gC1q-R to not only C1q itself but also a variety of circulating plasma proteins as well as its involvement in cell-to-cell interactions suggest that gC1q-R may have a role in tumor metastases and potentially serve in molecule-specific targeting of malignant cells. © 2004 Wiley-Liss, Inc. [source] Molecular Cloning and Characterization of a Gene Encoding a 13.1 kDa Antigenic Protein of Naegleria fowleriTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 6 2001HO-JOON SHIN ABSTRACT. An antigen-related gene was cloned from a cDNA expression library of Naegleria fowleri by immunoscreening with sera obtained from mice that were either immunized with an amoebic lysate or infected with trophozoites. The coding nucleotide sequence of the cloned gene consisted of 357 bases that were translated into 119 amino acids. This gene was designated as nfal. The predicted amino acid sequence of Nfal protein has two potential glycosylation and three potential phosphorylation sites, and its predicted secondary structure consists of four helices and three corners. The deduced amino acid sequence of Nfal protein shares 43% identity with the myohemerythrin (myoHr) protein from a marine annelid, Nereis diversicolor, including 100% identity in conserved regions and iron-binding residues. A phylogenetic tree constructed from amino acid sequences placed the N. fowleri Nfal protein outside of a cluster of myoHr proteins from eight invertebrates. A purified recombinant protein that migrated as a 13.1 kDa species in SDS-PAGE was produced. This recombinant protein exhibited a strong immunoreactivity with infected, immune, and anti-Nfal sera. In addition. an anti-Nfal serum reacted with an amoeba lysate in immunoblotting analysis. The present nfal gene encoding the myoHr-like protein is the first myoHr gene cloned from protozoa, and the Nfal antigen may be useful in diagnostic studies. [source] Synthetic small interfering RNA targeting heat shock protein 105 induces apoptosis of various cancer cells both in vitro and in vivoCANCER SCIENCE, Issue 7 2006Seiji Hosaka We previously reported that heat shock protein 105 (HSP105), identified by serological analysis of a recombinant cDNA expression library (SEREX) using serum from a pancreatic cancer patient, was overexpressed in various human tumors and in the testis of adult men by immunohistochemical analysis. In the present study, to elucidate the biological function of the HSP105 protein in cancer cells, we first established NIH3T3 cells overexpressing murine HSP105 (NIH3T3-HSP105). The NIH3T3-HSP105 cells acquired resistance to apoptosis induced by heat shock or doxorubicin. The small interfering RNA (siRNA)-mediated suppression of HSP105 protein expression induced apoptosis in human cancer cells but not in fibroblasts. By a combination of siRNA introduction and doxorubicin or heat shock treatment, apoptosis was induced synergistically in a human colon cancer cell line, HCT116. In vivo, siRNA inoculation into the human gastric cancer cell line KATO-3 established in the flank of an NOD SCID mouse suppressed the tumor growth. This siRNA-induced apoptosis was mediated through caspases, but not the p53 tumor suppressor protein, even though the HSP105 protein was bound to wild-type p53 protein in HCT116 cells. These findings suggest that the constitutive overexpression of HSP105 in cancer cells is involved in malignant transformation by protecting tumor cells from apoptosis. HSP105 may thus be a novel target molecule for cancer therapy and a treatment regimen using synthetic siRNA to suppress the expression of HSP105 protein may provide a new strategy for cancer therapy. (Cancer Sci 2006; 97: 623,632) [source] Electrophysiological Characteristics Of The Ca2+ -Activated Cl, Channel Family Of Anion Transport ProteinsCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 11 2000Catherine M Fuller SUMMARY 1. A protein isolated from the bovine tracheal epithelium behaves as a Ca2+ -activated Cl, channel (CaCC) when incorporated into planar lipid bilayers. 2. An antibody raised against this protein was used to screen a cDNA expression library and resulted in the isolation of a cDNA clone that exhibited nearly identical electrophysiological characteristics to the isolated endogenous protein when expressed. 3. Recent cloning of several related proteins has revealed that the cloned bovine CaCC is one of a large and growing family. All new family members so far examined are associated with the appearance of a novel Ca2+ -mediated Cl, conductance when heterologously expressed. 4. This new group of proteins may underlie the Ca2+ -mediated Cl, conductance upregulated in the cystic fibrosis (CF) knockout mouse and thought to be responsible for the escape from the significant airway pathology associated with CF. [source] | ||||||||||