RESUMO
Transthyretin (TTR), the precursor protein for amyloidogenic TTR (ATTR) amyloidosis, forms tetramers and escapes glomerular filtration by binding with thyroxine and retinol-binding protein. However, variant TTRs are unstable as tetramers, so monomeric TTR has become the precursor protein of amyloid deposits, via protein misfolding. The aim of the study was to evaluate the utility of urinary TTR in the diagnosis of ATTRv amyloidosis. Urinary samples from healthy volunteers, ATTRv V50M amyloidosis patients, and asymptomatic carriers of the ATTRv V50M gene were analysed using ELISA. To analyse the different forms of TTR secreted to the urine, we performed Western blotting and mass spectrometry. Urinary TTR concentrations were significantly higher in the ATTRv V50M amyloidosis patients than they were in the healthy volunteers and asymptomatic carriers of the gene. Although the TTR concentrations were negligible in the healthy volunteers, they were correlated with disease progression and urinary albumin concentrations in the ATTRv V50M amyloidosis patients. The Western blotting and mass spectrometry revealed the presence of monomeric wild-type and variant TTRs in the urine. Urinary TTR concentrations may become a more sensitive biomarker of ATTRv progression than albumin.
RESUMO
HMMC-1 is a human monoclonal antibody that reacts with a fucosylated and extended core 1 O-glycan, Fucα1-2Galß1-4GlcNAcß1-3Galß1-3GalNAc-Ser/Thr, as an epitope. In the present study, we examined the effects of HMMC-1 on cell proliferation of two human uterine endometrial cancer cell lines, HEC8 and HEC9, to investigate the role of glycoproteins bearing the HMMC-1 epitope in cancer progression. HEC9 cells expressed high levels of the HMMC-1 epitope, but HMMC-1 reactivity was hardly detected in HEC8 cells. In a mouse model of lymph node metastasis using orthotopic implantation, HEC8 and HEC9 showed low (10%) and high (80%) metastatic potency, respectively. Growth of HEC9, but not HEC8, was remarkably inhibited by addition of HMMC-1 to the culture medium. Cell cycle analysis and expression analysis showed that HMMC-1 treatment increased the G(1) phase population of HEC9 cells and induced cyclin-dependent kinase inhibitors p16 and p21. Two glycoproteins, 97 and 137 kDa, with a strong reactivity to HMMC-1 were purified, and the 97-kDa glycoprotein was identified as CD166, an immunoglobulin superfamily cell adhesion molecule assumed to be involved in cancer metastasis. CD166 gene-silencing dramatically reduced HMMC-1 epitope expression and growth in HEC9 cells, indicating that CD166 is the primary glycoprotein presenting the HMMC-1 epitope in HEC9 cells. Collectively, HMMC-1 might arrest the cell cycle in the G(1) phase by binding to O-glycans on the CD166 expressed in HEC9 cells, raising the possibility that HMMC-1 extensively inhibits invasive growth of HMMC-1 epitope-positive uterine endometrial cancer cells by targeting the cancer-associated form of CD166.
