Probing the interaction interface of the GADD45β/MKK7 and MKK7/DTP3 complexes by chemical cross-linking mass spectrometry

GADD45β is selectively and constitutively expressed in Multiple Myeloma cells, and this expression correlates with an unfavourable clinical outcome. GADD45β physically interacts with the JNK kinase, MKK7, inhibiting its activity to enable the survival of cancer cells. DTP3 is a small peptide inhibitor of the GADD45β/MKK7 complex and is able to restore MKK7/JNK activation, thereby promoting selective cell death of GADD45β-overexpressing cancer cells. Enzymatic MS foot-printing and diazirine-based chemical cross-linking MS (CX-MS) strategies were applied to study the interactions between GADD45β and MKK7 kinase domain (MKK7_KD) and between DTP3 and MKK7_KD. Our data show that the binding between GADD45β and MKK7 largely occurs between GADD45β loop 2 (region 103–117) and the kinase enzymatic pocket. We also show that DTP3 interferes with this GADD45β/MKK7 interaction by contacting the MKK7 peptides, 113–136 and 259–274. Accordingly, an MKK7_KD Δ(101–136) variant lacking Trp135 did not produce a fluorescence quenching effect upon the binding of DTP3. The assessment of the interaction between GADD45β and MKK7 and the elucidation of the recognition surfaces between DTP3 and MKK7 significantly advance the understanding of the mechanism underlying the inhibition of the GADD45β/MKK7 interaction by DTP3 and pave the way to the design of small-molecule DTP3 analogues

Baseline physical functioning status of metastatic colorectal cancer patients predicts the overall survival but not the activity of a front-line oxaliplatin-fluoropyrimidine doublet

No differences in response rate (RR), progression-free survival (PFS), overall survival (OS) and quality of life (QoL) were seen in patients randomly treated with biweekly oxaliplatin plus either fluorouracil/folinic acid or capecitabine

Characterization of Carbonic Anhydrase IX Interactome Reveals Proteins Assisting Its Nuclear Localization in Hypoxic Cells

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Le TIC a supporto dell\u2019inclusione nella scuola dell\u2019infanzia: un passo non ancora futuro.

L'esperienza del periodo di chiusura delle scuole a causa della pandemia ha dimostrato quanto possa essere prezioso il supporto digitale nella didattica, ma anche di quanto l'interazione tra docente e discenti sia fondamentale per lo sviluppo socio-cognitivo degli alunni. L'interazione quotidiana permette di impostare la didattica secondo le necessit\ue0 di tutti e di ciascuno, personalizzando gli interventi per gli alunni con Bisogni Educativi Speciali ma rendendoli utili a tutto il contesto sezione. Le strumentazioni digitali a scuola, offrono l\u2019opportunit\ue0 di potenziare le risorse disponibili arricchendo la didattica non solo dal punto di vista dell'accessibilit\ue0 alle discipline, bens\uec dal punto di vista della costruzione di contesti inclusivi. La tecnologia impiegata nello studio di alcune discipline \ue8 sia in grado di integrare l'esperienza dell'apprendimento scolastico, sia capace di supportare anche nuove strategie di cooperative learning. Anche nella scuola dell\u2019infanzia, il ruolo delle tecnologie \ue8 oggetto di indagini per valutare le possibili ricadute sia nei processi di insegnamento-apprendimento, sia nei processi di costruzione di un clima di classe accogliente e inclusivo

d-Peptide analogues of Boc-Phe-Leu-Phe-Leu-Phe-COOH induce neovascularization via endothelial N-formyl peptide receptor 3

N-formyl peptide receptors (FPRs) are G protein-coupled receptors involved in the recruitment and activation of immune cells in response to pathogen-associated molecular patterns. Three FPRs have been identified in humans (FPR1–FPR3), characterized by different ligand properties, biological function and cellular distribution. Recent findings from our laboratory have shown that the peptide BOC-FLFLF (l-BOC2), related to the FPR antagonist BOC2, acts as an angiogenesis inhibitor by binding to various angiogenic growth factors, including vascular endothelial growth factor-A165 (VEGF). Here we show that the all-d-enantiomer of l-BOC2 (d-BOC2) is devoid of any VEGF antagonist activity. At variance, d-BOC2, as well as the d-FLFLF and succinimidyl (Succ)-d-FLFLF (d-Succ-F3) d-peptide variants, is endowed with a pro-angiogenic potential. In particular, the d-peptide d-Succ-F3 exerts a pro-angiogenic activity in a variety of in vitro assays on human umbilical vein endothelial cells (HUVECs) and in ex vivo and in vivo assays in chick and zebrafish embryos and adult mice. This activity is related to the capacity of d-Succ-F3 to bind FRP3 expressed by HUVECs. Indeed, the effects exerted by d-Succ-F3 on HUVECs are fully suppressed by the G protein-coupled receptor inhibitor pertussis toxin, the FPR2/FPR3 antagonist WRW4 and by an anti-FPR3 antibody. A similar inhibition was observed following WRW4-induced FPR3 desensitization in HUVECs. Finally, d-Succ-F3 prevented the binding of the anti-FPR3 antibody to the cell surface of HUVECs. In conclusion, our data demonstrate that the angiogenic activity of d-Succ-F3 is due to the engagement and activation of FPR3 expressed by endothelial cells, thus shedding a new light on the biological function of this chemoattractant receptor

8-Chloro-cAMP enhances the growth inhibitory effect of cytotoxic drugs in human colon cancer cells

8-Cl-cAMP is a novel agent able to inhibit the growth of a wide variety of cancer cell types in vitro and in vivo by interfering with the protein kinase A type I (PKAI), a protein directly involved in mitogenic signalling and neoplastic transformation. In a recent phase I study conducted in cancer patients we have demonstrated that 8-Cl-cAMP, at doses devoid of toxicity, may achieve plasma concentrations in a range previously shown effective for cancer cell growth inhibition. In the present study we have investigated the effect of 8-Cl-cAMP in association with cytotoxic drugs acting by different mechanisms of action on the growth of LS174T and GEO human colon cancer cells. We here demonstrate that 8-Cl-cAMP administered after the cytotoxic drugs does not interfere with their growth inhibitory effect but rather is additive with most of them. Moreover, a synergistic effect was observed when 8-Cl-cAMP was administered after cisplatin or paclitaxel. The sequence of treatment seems to be important since pretreatment with 8-Cl-cAMP interferes with the effect of the cytoxic drugs. These results demonstrate that 8-Cl-cAMP is not only able to induce cell growth inhibition when used alone but also exhibit the capacity to enhance the efficacy of different cytotoxic drugs