The ubiquitin-dependent ATPase p97 removes cytotoxic trapped PARP1 from chromatin

Poly (ADP-ribose) polymerase (PARP) inhibitors elicit antitumour activity in homologous recombination-defective cancers by trapping PARP1 in a chromatin-bound state. How cells process trapped PARP1 remains unclear. Using wild-type and a trapping-deficient PARP1 mutant combined with rapid immunoprecipitation mass spectrometry of endogenous proteins and Apex2 proximity labelling, we delineated mass spectrometry-based interactomes of trapped and non-trapped PARP1. These analyses identified an interaction between trapped PARP1 and the ubiquitin-regulated p97 ATPase/segregase. We found that following trapping, PARP1 is SUMOylated by PIAS4 and subsequently ubiquitylated by the SUMO-targeted E3 ubiquitin ligase RNF4, events that promote recruitment of p97 and removal of trapped PARP1 from chromatin. Small-molecule p97-complex inhibitors, including a metabolite of the clinically used drug disulfiram (CuET), prolonged PARP1 trapping and enhanced PARP inhibitor-induced cytotoxicity in homologous recombination-defective tumour cells and patient-derived tumour organoids. Together, these results suggest that p97 ATPase plays a key role in the processing of trapped PARP1 and the response of tumour cells to PARP inhibitors.

Synthesis, Characterization and in vitro Anticancer Studies of New Co(II), Ni(II), Cu(II) and Zn(II) Complexes of (E)-4-((Quinoline-8-ylimino)methyl)benzene-1,2,3-triol Ligand

Herein, a new tridentate (NNO) Schiff base ligand, (E)-4-[(quinoline-8-ylimino)methyl]benzene-1,2,3- triol derived from the condensation of 8-aminoquinoline with 2,3,4-trihydroxy benzaldehyde is reported. The ligand was complexed with certain metal ions like Co(II) (1), Ni(II) (2), Cu(II) (3), Zn(II) (4) and were characterized by various spectroscopic and analytical techniques such as FT-IR, UV-Vis, 1H NMR, 13C NMR, ESI-Mass, ESR, elemental analysis and magnetic susceptibility. Spectral data revealed octahedral geometry for cobalt(II), nickel(II), copper(II) complexes and tetrahedral geometry for zinc(II) complex. All the metal(II) complexes along with the Schiff base ligand were screened for their anticancer activities. The CT-DNA binding studies revealed high binding propensity for metal complexes with Kb values 1.50 × 104 M-1 for 1; 3.62 × 104 M-1 for 2; 2.53 × 104 M-1 for 3 and 1.8 × 104 M-1 for 4, respectively. Anticancer studies against A549 & MCF-7 demonstrated excellent antiproliferative activity with IC50 values in the range 17.62-48.82 μM. A standard drug cisplatin was employed to compare the activity of metal complexes. The complexes exhibited remarkable antitumour activity due to their high binding ability with DNA. It is interesting to observe that the complexes did not produce any cytotoxicity towards the normal cell lines.

The Tumour Suppressor CYLD Is Required for Clathrin-Mediated Endocytosis of EGFR and Cetuximab-Induced Apoptosis in Head and Neck Squamous Cell Carcinoma

Epidermal growth factor receptor (EGFR) is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC) and is a target for the therapeutic antibody cetuximab (CTX). However, because only some patients have a significant clinical response to CTX, identification of its predictive biomarkers and potentiation of CTX-based therapies are important. We have recently reported a frequent downregulation of cylindromatosis (CYLD) in primary HNSCC, which led to increased cell invasion and cisplatin resistance. Here, we show that CYLD located mainly in lipid rafts was required for clathrin-mediated endocytosis (CME) and degradation of the EGFR induced by EGF and CTX in HNSCC cells. The N-terminus containing the first cytoskeleton-associated protein-glycine domain of CYLD was responsible for this regulation. Loss of CYLD restricted EGFR to lipid rafts, which suppressed CTX-induced apoptosis without impeding CTX’s inhibitory activity against downstream signalling pathways. Disruption of the lipid rafts with cholesterol-removing agents overcame this resistance by restoring CME and the degradation of EGFR. Regulation of EGFR trafficking by CYLD is thus critical for the antitumour activity of CTX. Our findings suggest the usefulness of a combination of cholesterol-lowering drugs with anti-EGFR antibody therapy in HNSCC.

Anlotinib Suppresses Oral Squamous Cell Carcinoma Growth and Metastasis by Targeting the RAS Protein to Inhibit the PI3K/Akt Signalling Pathway

Oral squamous cell carcinoma (OSCC) is a malignant tumour originating from the mucosal lining of the oral cavity. Its characteristics include hidden onset, high recurrence, and distant metastasis after operation. At present, clinical treatment usually includes surgery, chemotherapy, radiotherapy, or the joint use of these modalities. Unfortunately, multidrug resistant is one of the important obstacles that causes cancer chemotherapy failure. Anlotinib, which has recently been proven to have good antitumour effects, is a novel multitargeted tyrosine kinase inhibitor. However, there are few studies of the anlotinib-associated mechanism in OSCC and its underlying molecular mechanism. In our study, in vitro models of human oral squamous cell carcinoma HSC-3 cells were used to determine the efficacy of anlotinib. On the one hand, we showed that anlotinib treatment significantly reduced the viability and proliferation of HSC-3 cells and decreased cell migration by inhibiting the activation of the Akt phosphorylation pathway. On the other side, anlotinib inhibited PI3K/Akt/Bad phosphorylation and promoted apoptosis of HSC-3 cells by activating RAS protein expression. In brief, these results indicated that anlotinib had prominent antitumour activity in OSCC, mainly by inhibiting the PI3K/Akt phosphorylation pathway. This work provides evidences and a basic principle for using anlotinib to treat patients with OSCC for clinical research.

Eribulin activity in soft tissue sarcoma monolayer and three-dimensional cell line models: could the combination with other drugs improve its antitumoral effect?

Background Eribulin has shown antitumour activity in some soft tissue sarcomas (STSs), but it has only been approved for advanced liposarcoma (LPS). Methods In this study, we evaluated the effect of eribulin on proliferation, migration and invasion capabilities in LPS, leiomyosarcoma (LMS) and fibrosarcoma (FS) models, using both monolayer (2D) and three-dimensional (3D) spheroid cell cultures. Additionally, we explored combinations of eribulin with other drugs commonly used in the treatment of STS with the aim of increasing its antitumour activity. Results Eribulin showed activity inhibiting proliferation, 2D and 3D migration and invasion in most of the cell line models. Furthermore, we provide data that suggest, for the first time, a synergistic effect with ifosfamide in all models, and with pazopanib in LMS as well as in myxoid and pleomorphic LPS. Conclusions Our results support the effect of eribulin on LPS, LMS and FS cell line models. The combination of eribulin with ifosfamide or pazopanib has shown in vitro synergy, which warrants further clinical research.

BET protein inhibition evidently enhances sensitivity to PI3K/mTOR dual inhibition in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC), the second most common primary liver cancer, is a fatal malignancy with a poor prognosis and only very limited therapeutic options. Although molecular targeted therapy is emerged as a promising treatment strategy, resistance to molecular-targeted therapy occurs inevitably, which represents a major clinical challenge. In this study, we confirmed that mammalian target of rapamycin (mTOR) signaling is the most significantly affected pathways in ICC. As a novel phosphoinositide 3-kinase (PI3K)/mTOR dual inhibitor, BEZ235, exerts antitumour activity by effectively and specifically blocking the dysfunctional activation of the PI3K/serine/threonine kinase (AKT)/mTOR pathway. We generate the orthotopic ICC mouse model through hydrodynamic transfection of AKT and yes-associated protein (YAP) plasmids into the mouse liver. Our study confirmed that BEZ235 can suppress the proliferation, invasion and colony conformation abilities of ICC cells in vitro but cannot effectively inhibit ICC progression in vivo. Inhibition of PI3K/mTOR allowed upregulation of c-Myc and YAP through suppressed the phosphorylation of LATS1. It would be a novel mechanism that mediated resistance to PI3K/mTOR dual inhibitor. However, Bromo- and extraterminal domain (BET) inhibition by JQ1 downregulates c-Myc and YAP transcription, which could enhance the efficacy of PI3K/mTOR inhibitors. The efficacy results of combination therapy exhibited effective treatment on ICC in vitro and in vivo. Our data further confirmed that the combination of PI3K/mTOR dual inhibitor and BET inhibition induces M1 polarization and suppresses M2 polarization in macrophages by regulating the expression of HIF-1α. Our study provides a novel and efficient therapeutic strategy in treating primary ICC.

Therapeutic Potential of Innate Lymphoid Cells for Multiple Myeloma Therapy

Innate lymphoid cells (ILCs) are a recently identified family of lymphocyte-like cells lacking a specific antigen receptor. They are part of the innate immune system. They play a key role in tissue homeostasis and also control inflammatory and neoplastic processes. In response to environmental stimuli, ILCs change their phenotype and functions, and influence the activity of other cells in the microenvironment. ILC dysfunction can lead to a wide variety of diseases, including cancer. ILC can be divided into three subgroups: ILC Group 1, comprising NK cells and ILC1; Group 2, including ILC2 alone; and Group 3, containing Lymphoid Tissue inducers (LTi) and ILC3 cells. While Group 1 ILCs mainly exert antitumour activity, Group 2 and Group 3 ILCs are protumorigenic in nature. A growing body of preclinical and clinical data support the role of ILCs in the pathogenesis of multiple myeloma (MM). Therefore, targeting ILCs may be of clinical benefit. In this manuscript, we review the available data on the role of ILCs in MM immunology and therapy.

A review on kalanchoe pinnata (Crassulaceae)

The primary goal of this study is to offer preliminary data for drug discovery research using Kalanchoe pinnata a heavenly plant that has a broad variety of active chemicals, including alkaloids, Phenols, Phenylpropanoids, Flavanoids, Triterpenoids, steroids, organic Salts. This plant was discovered to have a variety of pharmacological properties, including Antihypertensiveactivity, Hepatoprotective activity, Antimutagenic activity, Anti-ulcer activity, Uterine Contractility, Antidiabetic activity, Wound-healing activity, Antioxidant activity, Antitumour activity, Antiviral activity, Antimicrobial activity, Antileishmanial activity, Insecticidal activity, Antipyreticactivity, Antilithiatic activity, Neuropharmacological Immunosuppressive antibacterial activity, Cytotoxicity of testis. This study provides phytoconstituents and pharmacological activity of K. pinnata, a medicinal plant that may help researchers conduct more advanced qualitative research.