Abstract MicroRNA-130b (miR-130b) is involved in several biologic processes; its role in colorectal tumorigenesis has not been addressed so far. Herein, we demonstrate that miR-130b up-regulation ...exhibits clinical relevance as it is linked to advanced colorectal cancers (CRCs), poor patients' prognosis, and molecular features of enhanced epithelial-mesenchymal transition (EMT) and angiogenesis. miR-130b high-expressing cells develop large, dedifferentiated, and vascularized tumors in mouse xenografts, features that are reverted by intratumor injection of a specific antisense RNA. In contrast, injection of the corresponding mimic in mouse xenografts from miR-130b low-expressing cells increases tumor growth and angiogenic potential while reduces the epithelial hallmarks. These biologic effects are reproduced in human CRC cell lines. We identify peroxisome proliferator-activated receptor γ (PPARγ) as an miR-130b direct target in CRC in vitro and in vivo . Notably, the effects of PPARγ gain- and loss-of-function phenocopy those due to miR-130b down-regulation or up-regulation, respectively, underscoring their biologic relevance. Furthermore, we provide mechanistic evidences that most of the miR-130b-dependent effects are due to PPARγ suppression that in turn deregulates PTEN, E-cadherin, Snail, and vascular endothelial growth factor, key mediators of cell proliferation, EMT, and angiogenesis. Since higher levels of miR-130b are found in advanced tumor stages (III–IV), we propose a novel role of the miR-130b-PPARγ axis in fostering the progression toward more invasive CRCs. Detection of onco-miR-130b and its association with PPARγ may be useful as a prognostic biomarker. Its targeting in vivo should be evaluated as a novel effective therapeutic tool against CRC.
Antibody drug conjugates represent an important class of anti-cancer drugs in both solid tumors and hematological cancers. Here, we report preclinical data on the anti-tumor activity of the ...first-in-class antibody drug conjugate MEN1309/OBT076 targeting CD205. The study included preclinical in vitro activity screening on a large panel of cell lines, both as single agent and in combination and validation experiments on in vivo models. CD205 was first shown frequently expressed in lymphomas, leukemias and multiple myeloma by immunohistochemistry on tissue microarrays. Anti-tumor activity of MEN1309/OBT076 as single agent was then shown across 42 B-cell lymphoma cell lines with a median IC50 of 200 pM and induction of apoptosis in 25/42 (59.5%) of the cases. The activity appeared highly correlated with its target expression. After in vivo validation as the single agent, the antibody drug conjugate synergized with the BCL2 inhibitor venetoclax, and the anti-CD20 monoclonal antibody rituximab. The first-in-class antibody drug targeting CD205, MEN1309/OBT076, demonstrated strong pre-clinical anti-tumor activity in lymphoma, warranting further investigations as a single agent and in combination.
Background
Lung cancer remains the leading cause of cancer-related death worldwide. Targeted therapies with tyrosine kinase inhibitors (TKIs) result in improvement in survival for non-small cell lung ...cancer (NSCLC) with activating mutations of the epidermal growth factor receptor (EGFR). Unfortunately, most patients who initially respond to EGFR-TKI ultimately develop resistance to therapy, resulting in cancer progression and relapse. Combination therapy is today a common strategy for the treatment of tumors to increase the success rate, improve the outcome and survival of patients, and avoid the selection of resistant cancer cells through the activation of compensatory pathways. In NSCLC, the phosphoinositide-3-kinase/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway has been heavily implicated in both tumorigenesis and the progression of disease.
Objectives
In this study, we investigated the efficacy of a PI3K δ-sparing inhibitor, MEN1611, in models of NSCLC sensitive and resistant to EGFR inhibitors (erlotinib and gefitinib) with a wild-type
PIK3CA
gene.
Methods
We performed functional, biochemical, and immunohistochemistry studies.
Results
We demonstrated good efficacy of MEN1611 in NSCLC devoid of
PIK3CA
gene mutations but with constitutive activation of the PI3K/AKT pathway and its synergistic effect with gefitinib both
in vitro
and
in vivo
.
Conclusions
Overall, this preclinical study indicates that the inhibitor could be a candidate for the treatment of NSCLC with an erlotinib/gefitinib-resistant phenotype and constitutive activation of the PI3K/AKT pathway, a phenotype mimicked by our model system.
Histone deacetylases are promising molecular targets for the development of antitumor agents. A novel series of histone deacetylase inhibitors of the hydroxamic acid type were synthesized for ...structure−activity studies. Thirteen tricyclic dibenzo-diazepine, -oxazepine, and -thiazepine analogues were studied and shown to induce variable degrees of histone H3/H4 and tubulin acetylation in a cellular model of myeloid leukemia sensitive to all-trans retinoic acid (ATRA). Multiparametric correlations between acetylation of the three substrates, tumor cell growth inhibition, and ATRA-dependent cytodifferentiation were performed, providing information on the chemical functionalities governing these activities. For two analogues, antitumor activity in the animal was demonstrated.
Chemical agents able to interfere with DNA topoisomerases are widespread in nature, and some of them have clinical efficacy as antitumor or antibacterial drugs. Drugs which have as a target DNA ...topoisomerases could be divided into two categories: poisons and catalytic inhibitors. Classical topoisomerase poisons stimulate cleavage in a sequence-selective manner, yielding drug-specific cleavage intensity pattern. The mechanisms of drug interaction with DNA topoisomerases, the DNA sequence selectivity of the action of topoisomerase II poisons and the identification of structural determinants of their activity have suggested that topoisomerase II poisons may fit into a specific pharmacophore, constituted by a planar ring system with DNA intercalation or intercalation-like properties, and protruding side chains interfering with the protein side of the covalent enzyme–DNA complex. The complete definition of the diverse pharmacophores of topoisomerase II poisons will certainly be of value for the design of new agents directed to specific genomic sites, and more effective in the treatment of human cancer.
Several antitumor drugs have been described to induce nuclear factor kappaB (NF-kappaB), but results about its role in regulating apoptotic cell death are quite controversial. In this paper, we ...studied NF-kappaB induced by the two anticancer agents Sabarubicin (MEN 10755) and paclitaxel (Taxol) and the effects of its pharmacological inhibition.
In the human colon cancer cell line HCT-116, we investigated NF-kappaB activation induced by the two anticancer agents using electrophoretic mobility shift assay (EMSA), while drug-induced cytotoxicity was measured by trypan blue staining. Apoptosis was analyzed using a cell death detection enzyme-linked immunosorbent assay (ELISA) kit, flow cytometry and caspase-3 activation assay.
The combination with the NF-kappaB inhibitorparthenolide increased Sabarubicin- but not paclitaxel-induced cell death. EMSA experiments demonstrated that the two antitumor drugs induced NF-kappaB complexes with different kinetics but similar subunit composition. Moreover, Sabarubicin elicited NF-kappaB activation definitely earlier than DNA fragmentation, whereas with paclitaxel the kinetics of the two phenomena were similar.
Purpose
Dysregulation of the PI3K pathway is one of the most common events in breast cancer. Here we investigate the activity of the PI3K inhibitor MEN1611 at both molecular and phenotypic levels by ...dissecting and comparing its profile and efficacy in HER2 + breast cancer models with other PI3K inhibitors.
Methods
Models with different genetic backgrounds were used to investigate the pharmacological profile of MEN1611 against other PI3K inhibitors. In vitro studies evaluated cell viability, PI3K signaling, and cell death upon treatment with MEN1611. In vivo efficacy of the compound was investigated in cell line- and patient-derived xenografts models.
Results
Consistent with its biochemical selectivity, MEN1611 demonstrated lower cytotoxic activity in a p110δ-driven cellular model when compared to taselisib, and higher cytotoxic activity in the p110β-driven cellular model when compared to alpelisib. Moreover, MEN1611 selectively decreased the p110α protein levels in PIK3CA mutated breast cancer cells in a concentration- and proteasome-dependent manner. In vivo, MEN1611 monotherapy showed significant and durable antitumor activity in several trastuzumab-resistant PIK3CA-mutant HER2 + PDX models. The combination of trastuzumab and MEN1611 significantly improved the efficacy compared to single agent treatment.
Conclusions
The profile of MEN1611 and its antitumoral activity suggest an improved profile as compared to pan-inhibitors, which are limited by a less than ideal safety profile, and isoform selective molecules, which may potentially promote development of resistance mechanisms. The compelling antitumor activity in combination with trastuzumab in HER2 + trastuzumab-resistant, PIK3CA mutated breast cancer models is at the basis of the ongoing B-Precise clinical trial (NCT03767335).
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