Identification of nucleolar protein No55 as a tumour-associated autoantigen in patients with prostate cancer

Abstract

Four different genes were identified by immunoscreening of a cDNA expression library from the human prostate cancer cell line DU145 with allogeneic sera from four prostate cancer patients. A cDNA encoding the nucleolar protein No55 was further analysed and shown to be expressed at the mRNA level in several normal tissues, including ovaries, pancreas and prostate and in human prostate cancer cell lines PC-3, PC-3m and LNCaP. By reverse transcriptase/polymerase chain reaction, expression of No55 was several-fold higher in two out of nine prostate cancer primary tumours and two out of two metastatic lesions, compared to normal prostate tissue. Antibodies to No55 were detected in sera from seven out of 47 prostate cancer patients but not in sera from 20 healthy male controls. Sequence analysis of the No55 open reading frame from normal and tumour tissues revealed no tumour-specific mutations. The No55 gene was located to chromosome 17q21, a region reported to be partially deleted in prostate cancer. Considering the immunogenicity of the No55 protein in the tumour host, the expression profile and chromosomal localization of the corresponding gene, studies evaluating No55 as a potential antigen for immunological studies in prostate cancer may be warranted. © 2000 Cancer Research Campaign

Sc65 Is a Novel Endoplasmic Reticulum Protein That Regulates Bone Mass Homeostasis

“…Sc65 was initially described as a rat synaptonemal complex protein of 65 kDa (and hence its name) expressed in testis, brain, heart, and, to a lesser extent, in the liver . Subsequently, it was also identified as a human tumor‐associated autoantigen and as a 55 kDa nucleolar protein (also named NO55) . Sc65 was also described as a cytoplasmic “adapter protein” capable of interacting directly with the cytoplasmic tail of myelin protein zero (P0) and the receptor for activated C kinase 1 (RACK1) .…”

Serum autoantibodies as biomarkers for early cancer detection

“…The application of SEREX has facilitated the identification of TAAs as potential cancer biomarkers [81,82] in various types of cancer, including lung, liver, breast, prostate, ovarian, renal, head and neck, and esophageal cancers, and in leukemia and melanoma [83][84][85][86][87][88][89][90][91]. The panel of SEREX-defined immunogenic tumor antigens include CTAs (e.g.…”

Etiologic theories of chronic prostatitis/chronic pelvic pain syndrome

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