1.Sensitivity of Human Intrahepatic Cholangiocarcinoma Subtypes to Chemotherapeutics and Molecular Targeted Agents: A Study on Primary Cell Cultures.
Fraveto A1, Cardinale V1, Bragazzi MC1, Giuliante F2, De Rose AM2, Grazi GL3, Napoletano C4, Semeraro R1, Lustri AM1, Costantini D1, Nevi L1, Di Matteo S1, Renzi A5, Carpino G6, Gaudio E5, Alvaro D1. PLoS One. 2015 Nov 16;10(11):e0142124. doi: 10.1371/journal.pone.0142124. eCollection 2015.
We investigated the sensitivity of intrahepatic cholangiocarcinoma (IHCCA) subtypes to chemotherapeutics and molecular targeted agents. Primary cultures of mucin- and mixed-IHCCA were prepared from surgical specimens (N. 18 IHCCA patients) and evaluated for cell proliferation (MTS assay) and apoptosis (Caspase 3) after incubation (72 hours) with increasing concentrations of different drugs. In vivo, subcutaneous human tumor xenografts were evaluated. Primary cultures of mucin- and mixed-IHCCA were characterized by a different pattern of expression of cancer stem cell markers, and by a different drug sensitivity. Gemcitabine and the Gemcitabine-Cisplatin combination were more active in inhibiting cell proliferation in mixed-IHCCA while Cisplatin or Abraxane were more effective against mucin-IHCCA, where Abraxane also enhances apoptosis. 5-Fluoracil showed a slight inhibitory effect on cell proliferation that was more significant in mixed- than mucin-IHCCA primary cultures and, induced apoptosis only in mucin-IHCCA.
2.Structural basis for substrate specificity of Helicobacter pylori M17 aminopeptidase.
Modak JK1, Rut W2, Wijeyewickrema LC3, Pike RN3, Drag M2, Roujeinikova A4. Biochimie. 2016 Feb;121:60-71. doi: 10.1016/j.biochi.2015.11.021. Epub 2015 Dec 1.
The M17 aminopeptidase from the carcinogenic gastric bacterium Helicobacter pylori (HpM17AP) is an important housekeeping enzyme involved in catabolism of endogenous and exogenous peptides. It is implicated in H. pylori defence against the human innate immune response and in the mechanism of metronidazole resistance. Bestatin inhibits HpM17AP and suppresses H. pylori growth. To address the structural basis of catalysis and inhibition of this enzyme, we have established its specificity towards the N-terminal amino acid of peptide substrates and determined the crystal structures of HpM17AP and its complex with bestatin. The position of the D-phenylalanine moiety of the inhibitor with respect to the active-site metal ions, bicarbonate ion and with respect to other M17 aminopeptidases suggested that this residue binds to the S1 subsite of HpM17AP. In contrast to most characterized M17 aminopeptidases, HpM17AP displays preference for L-Arg over L-Leu residues in peptide substrates.
3.Ubenimex inhibits cell proliferation, migration and invasion by inhibiting the expression of APN and inducing autophagic cell death in prostate cancer cells.
Wang X1, Niu Z1, Jia Y2, Cui M2, Han L3, Zhang Y4, Liu Z1, Bi D1, Liu S1. Oncol Rep. 2016 Apr;35(4):2121-30. doi: 10.3892/or.2016.4611. Epub 2016 Feb 3.
Prostate cancer is the second most frequently diagnosed cancer in males worldwide and is commonly associated with metastasis. Moreover, in prostate cancer, aminopeptidase N (APN) expression is closely correlated with metastasis. Ubenimex, an APN inhibitor, is widely used as an adjunct therapy for cancer, enhancing the function of immunocompetent cells and conferring antitumor effects. However, due to the low expression of APN, it is rarely used to treat prostate cancer. Recently, the induction of autophagy as a molecular mechanism has been strongly connected with tumor cell death. Thus, we investigated whether ubenimex could inhibit cell proliferation, migration and invasion by downregulating APN expression to induce autophagic cell death in prostate cancer cells. The LNCaP and PC-3 cell lines were treated with different doses of ubenimex. Cell viability was measured using growth curve analysis and WST-8 proliferation assay. Autophagic cell death was assessed using fluorescence microscopy and acridine orange/ethidium bromide (AO/EB) staining.
4.[Bioequivalence of Ubenimex Capsules in Healthy Volunteers].
Zheng J, Xiang J, Miao J, Yu Q, Hu C, Qin YP, Shu SQ, Nan F, Wang Y, Zhu XH. Sichuan Da Xue Xue Bao Yi Xue Ban. 2016 Jan;47(1):85-9, 92.
OBJECTIVE: To evaluate bioequivalence of two specifications of ubenimex capsules in comparison with the Japanese branded product (R).