bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Human colorectal tumors and metastases express Gb3 and can be targeted by an intestinal pathogen-based delivery tool
Authors: Falguières Thomas , Maak Matthias , von Weyhern Claus , Sarr Marianne , Sastre Xavier , Poupon Marie-France , Robine Sylvie , Johannes Ludger , Janssen Klaus-Peter
Published: April 2023

Abstract
The targeting of solid tumors requires delivery tools that resist intracellular and extracellular inactivation, and that are taken up specifically by tumor cells. We have shown previously that the recombinant nontoxic B-subunit of Shiga toxin (STxB) can serve as a delivery tool to target digestive tumors in animal models. The aim of this study was to expand these experiments to human colorectal cancer. Tissue samples of normal colon, benign adenomas, colorectal carcinomas, and liver metastases from 111 patients were obtained for the quantification of the expression of the cellular STxB receptor, the glycosphingolipid globotriaosyl ceramide (Gb3 or CD77). We found that compared with normal tissue, the expression of Gb3 was strongly increased in colorectal adenocarcinomas and their metastases, but not in benign adenomas. Short-term primary cultures were prepared from samples of 43 patients, and STxB uptake was studied by immunofluorescence microscopy. Of a given tumor sample, on average, 80% of the cells could visibly bind STxB, and upon incubation at 37°C, STxB was transported to the Golgi apparatus, following the retrograde route. This STxB-specific intracellular targeting allows the molecule to avoid recycling and degradation, and STxB could consequently be detected on tumor cells even 5 days after initial uptake. In conclusion, the targeting properties of STxB could be diverted for the delivery of contrast agents to human colorectal tumors and their metastases, whose early detection and specific targeting remains one of the principal challenges in oncology. [Mol Cancer Ther 2008;7(8):2498–508]
Data from Relevance of the Fanconi anemia pathway in the response of human cells to trabectedin
Authors: Casado José A. , Río Paula , Marco Esther , García-Hernández Verónica , Domingo Alberto , Pérez Laura , Tercero Juan Carlos , Vaquero Juan José , Albella Beatriz , Gago Federico , Bueren Juan A.
Published: April 2023

Abstract
Trabectedin (Yondelis; ET-743) is a potent anticancer drug that binds to DNA by forming a covalent bond with a guanine in one strand and one or more hydrogen bonds with the opposite strand. Using a fluorescence-based melting assay, we show that one single trabectedin-DNA adduct increases the thermal stability of the double helix by >20°C. As deduced from the analysis of phosphorylated H2AX and Rad51 foci, we observed that clinically relevant doses of trabectedin induce the formation of DNA double-strand breaks in human cells and activate homologous recombination repair in a manner similar to that evoked by the DNA interstrand cross-linking agent mitomycin C (MMC). Because one important characteristic of this drug is its marked cytotoxicity on cells lacking a functional Fanconi anemia (FA) pathway, we compared the response of different subtypes of FA cells to MMC and trabectedin. Our data clearly show that human cells with mutations in FANCA, FANCC, FANCF, FANCG, or FANCD1 genes are highly sensitive to both MMC and trabectedin. However, in marked contrast to MMC, trabectedin does not induce any significant accumulation of FA cells in G2-M. The critical relevance of FA proteins in the response of human cells to trabectedin reported herein, together with observations showing the role of the FA pathway in cancer suppression, strongly suggest that screening for mutations in FA genes may facilitate the identification of tumors displaying enhanced sensitivity to this novel anticancer drug. [Mol Cancer Ther 2008;7(5):1309–18]
Data from Aminopeptidase inhibition as a targeted treatment strategy in myeloma
Authors: Moore Hannah E. , Davenport Emma L. , Smith Emma M. , Muralikrishnan Srikanth , Dunlop Alan S. , Walker Brian A. , Krige David , Drummond Alan H. , Hooftman Leon , Morgan Gareth J. , Davies Faith E.
Published: April 2023

Abstract
Myeloma cells are highly dependent on the unfolded protein response to assemble folded immunoglobulins correctly. Therefore, targeting protein handling within a myeloma cell by inhibiting the aminopeptidase enzyme system, which catalyses the hydrolysis of amino acids from the proteins NH2 terminus, represents a therapeutic approach. CHR-2797, a novel aminopeptidase inhibitor, is able to inhibit proliferation and induce growth arrest and apoptosis in myeloma cells, including cells resistant to conventional chemotherapeutics. It causes minimal inhibition of bone marrow stromal cell (BMSC) proliferation but is able to overcome the microenvironmental protective effects, inhibiting the proliferation of myeloma cells bound to BMSCs and the increase in vascular endothelial growth factor levels seen when myeloma cells and BMSCs are bound together. Additive and synergistic effects are seen with bortezomib, melphalan, and dexamethasone. Apoptosis occurs via both caspase-dependent and non-caspase-dependent pathways with an increase in Noxa, cleavage of Mcl-1, and activation of the unfolded protein response. Autophagy is also seen. CHR-2797 causes an up-regulation of genes involved in the proteasome/ubiquitin pathway, as well as aminopeptidases, and amino acid deprivation response genes. In conclusion, inhibiting protein turnover using the aminopeptidase inhibitor CHR-2797 results in myeloma cell apoptosis and represents a novel therapeutic approach that warrants further investigation in the clinical setting. [Mol Cancer Ther 2009;8(4):762–70]
Data from Synergistic tumoricidal effect of combined hMUC1 vaccination and hNIS radioiodine gene therapy
Authors: Jeon Yong Hyun , Choi Yun , Yoon Sun Och , Kim Chul Woo , Chung June-Key
Published: April 2023

Abstract
We examined the merits of combinatorial hMUC1 vaccination and hNIS radioiodine gene therapy and evaluated its tumoricidal effects in an animal tumor model. CMNF (CT26 expressing hMUC1, hNIS, and firefly luciferase) cells were transplanted into 28 mice, and 4 and 11 days after tumor challenge, tumor-bearing mice were immunized i.m. with pcDNA3.1 or pcDNA-hMUC1 vaccine and subsequently administered PBS or 131I i.p. [four groups (7 mice per group): pcDNA3.1 + PBS, phMUC1 + PBS, pcDNA3.1 + 131I, and phMUC1 + 131I groups]. Thirty-two days after tumor challenge, we rechallenged mice in the pcDNA3.1 + 131I and phMUC1 + 131I groups with CMNF cells. Tumor progression and tumor-free mice (%) were monitored by bioluminescence. We investigated hMUC1-associated immune response generated by combination therapy. Marked tumor growth inhibition was observed in the phMUC1 + 131I group by bioluminescence at 32 days after tumor challenge. Mice in phMUC1 + 131I group showed complete hMUC1-expressing tumor suppression after tumor rechallenge, whereas mice in the pcDNA3.1 + 131I group did not. The tumor-free mice (%) were much higher in the phMUC1 + 131I group than in the other three groups. Levels of hMUC1-associated CD8+IFN-γ+ T cells were higher in the phMUC1 + 131I group than in the other three groups. hMUC1-loaded CD11+ cells in the phMUC1 + 131I group were found to be most effective at generating hMUC1-associated CD8+IFN-γ+ T cells. The activities of hMUC1-associated cytotoxic T cells in the phMUC1 + 131I group were higher than in the other three groups. Our data suggest that phMUC1 + 131I combination therapy synergistically generates marked tumoricidal effects against established hMUC1-expressing cancers. [Mol Cancer Ther 2008;7(7):2252–60]
Data from A small-molecule compound identified through a cell-based screening inhibits JAK/STAT pathway signaling in human cancer cells
Authors: Kim Byung Hak , Yin Chang-Hong , Guo Qianxu , Bach Erika A. , Lee Haeryun , Sandoval Claudio , Jayabose Somasundaram , Ulaczyk-Lesanko Agnieszka , Hall Dennis G. , Baeg Gyeong-Hun
Published: April 2023

Abstract
Inappropriate activation of JAK/STAT signaling occurs with high frequency in human cancers and is associated with cancer cell survival and proliferation. Therefore, the development of pharmacologic STAT signaling inhibitors has therapeutic potential in the treatment of human cancers. Here, we report 2-[(3,5-bis-trifluoromethyl-phenyl)-hydroxy-methyl]-1-(4-nitro-phenylamino)-6-phenyl-1,2,4a,7a-tetrahydro-pyrrolo[3,4-b]-pyridine-5,7-dione (AUH-6-96) as a novel small-molecule inhibitor of JAK/STAT signaling that we initially identified through a cell-based high-throughput screening using cultured Drosophila cells. Treatment of Drosophila cells with AUH-6-96 resulted in a reduction of Unpaired-induced transcriptional activity and tyrosine phosphorylation of STAT92E, the sole Drosophila STAT homologue. In human cancer cell lines, AUH-6-96 inhibited both constitutive and interleukin-6-induced STAT3 phosphorylation. Specifically, in Hodgkin lymphoma L540 cells, treatment with AUH-6-96 resulted in reduced levels of tyrosine phosphorylated STAT3 and of the STAT3 downstream target gene SOCS3 in a dose- and time-dependent manner. In addition, AUH-6-96-treated L540 cells showed decreased expression of persistently activated JAK3, suggesting that AUH-6-96 inhibits the JAK/STAT pathway signaling in L540 cells by affecting JAK3 activity and subsequently blocking STAT3 signaling. Importantly, AUH-6-96 selectively affected cell viability only of cancer cells harboring aberrant JAK/STAT signaling. In support of the specificity of AUH-6-96 for inhibition of JAK/STAT signaling, treatment with AUH-6-96 decreased cancer cell survival by inducing programmed cell death by down-regulating the expression of STAT3 downstream target antiapoptotic genes, such as Bcl-xL. In summary, this study shows that AUH-6-96 is a novel small-molecule inhibitor of JAK/STAT signaling and may have therapeutic potential in the treatment of human cancers harboring aberrant JAK/STAT signaling. [Mol Cancer Ther 2008;7(9):2672–80]
Data from Arsenic trioxide decreases AKT protein in a caspase-dependent manner
Authors: Mann Koren K. , Colombo Myrian , Miller Wilson H.
Published: April 2023

Abstract
Arsenic trioxide (As2O3) is used clinically to treat acute promyelocytic leukemia but is less successful in other malignancies. To identify targets for potential combination therapies, we have begun to characterize signaling pathways leading to As2O3-induced cytotoxicity. Previously, we described the requirement for a reactive oxygen species–mediated, SEK1/c-Jun NH2-terminal kinase (JNK) pathway to induce apoptosis. AKT inhibits several steps in this pathway; therefore, we postulated that As2O3 might decrease its activity. Indeed, As2O3 decreases not only AKT activity but also total AKT protein, and sensitivity to As2O3 correlates with the degree of AKT protein decrease. Decreased AKT expression further correlates with JNK activation and the release of AKT from the JNK-interacting protein 1 scaffold protein known to assemble the mitogen-activated protein kinase cascade. We found that As2O3 regulates AKT protein stability without significant effects on its transcription or translation. We show that As2O3 decreases AKT protein via caspase-mediated degradation, abrogated by caspase-6, caspase-8, caspase-9, and caspase-3 inhibitors but not proteosome inhibitors. Furthermore, As2O3 enhances the ability of a heat shock protein 90 inhibitor to decrease AKT expression and increase growth inhibition. This suggests that As2O3 may be useful in combination therapies that target AKT pathways or in tumors that have constitutively active AKT expression. [Mol Cancer Ther 2008;7(6):1680–7]
Data from Characterization of novel inhibitors of histone acetyltransferases
Authors: Eliseeva Elena D. , Valkov Vassil , Jung Manfred , Jung Mira O.
Published: April 2023

Abstract
Modification of proteins by histone acetyltransferases (HAT) or histone deacetylases plays an important role in the control of gene expression, and its dysregulation has been linked to malignant transformation and other diseases. Although histone deacetylase inhibitors have been extensively studied and several are currently in clinical trials, there is little information available on inhibitors of HATs (HATi). Starting from the natural product lead HATi anacardic acid, a series of 28 analogues was synthesized and investigated for HAT-inhibitory properties and effects on cancer cell growth. The compounds inhibited up to 95% HAT activity in vitro, and there was a clear correlation between their inhibitory potency and cytotoxicity toward a broad panel of cancer cells. Interestingly, all tested compounds were relatively nontoxic to nonmalignant human cell lines. Western blot analysis of MCF7 breast carcinoma cells treated with HATi showed significant reduction in acetylation levels of histone H4. To directly show effect of the new compounds on HAT activity in vivo, MCF7 cells were cotransfected with the p21 promoter fused to firefly luciferase and a full-length p300 acetyltransferase, and luciferase activity was determined following treatment with HATi. Significant inhibition of p300 activity was detected after treatment with all tested compounds except one. Effects of the new HATi on protein acetylation and HAT activity in vivo make them a suitable tool for discovery of molecular targets of HATs and, potentially, for development of new anticancer therapeutics. [Mol Cancer Ther 2007;6(9):2391–8]
Data from H2AX phosphorylation marks gemcitabine-induced stalled replication forks and their collapse upon S-phase checkpoint abrogation
Authors: Ewald Brett , Sampath Deepa , Plunkett William
Published: April 2023

Abstract
Gemcitabine is a nucleoside analogue that is incorporated into replicating DNA, resulting in partial chain termination and stalling of replication forks. The histone variant H2AX is phosphorylated on Ser139 (γ-H2AX) and forms nuclear foci at sites of DNA damage. Here, we characterize the concentration- and time-dependent phosphorylation of H2AX in response to gemcitabine-induced stalled replication forks. The number of γ-H2AX foci increased with time up to 2 to 6 h after exposure to gemcitabine, whereas longer exposures did not cause greater phosphorylation or increase cell death. The percentage of γ-H2AX–positive cells increased with concentrations of gemcitabine up to 0.1 μmol/L, and γ-H2AX was most evident in the S-phase fraction. Phosphorylation of ataxia-telangiectasia mutated (ATM) on Ser1981 was also associated with S-phase cells and colocalized in the nucleus with phosphorylated H2AX foci after gemcitabine exposure. Chemical inhibition of ATM, ATM- and Rad3-related, and DNA-dependent protein kinase blocked H2AX phosphorylation. H2AX and ATM phosphorylation were associated with inhibition of DNA synthesis, S-phase accumulation, and activation of the S-phase checkpoint pathway (Chk1/Cdc25A/cyclin-dependent kinase 2). Exposure of previously gemcitabine-treated cultures to the Chk1 inhibitor 7-hydroxystaurosporine (UCN-01) caused a 10-fold increase in H2AX phosphorylation, which was displayed as an even pan-nuclear staining. This increased phosphorylation was not due to apoptosis-induced DNA fragmentation and was associated with the S-phase fraction and decreased reproductive viability. Thus, H2AX becomes phosphorylated and forms nuclear foci in response to gemcitabine-induced stalled replication forks, and this is greatly increased upon checkpoint abrogation. [Mol Cancer Ther 2007;6(4):1239–48]
Data from TW-37, a small-molecule inhibitor of Bcl-2, mediates S-phase cell cycle arrest and suppresses head and neck tumor angiogenesis
Authors: Ashimori Naoki , Zeitlin Benjamin D. , Zhang Zhaocheng , Warner Kristy , Turkienicz Ilan M. , Spalding Aaron C. , Teknos Theodoros N. , Wang Shaomeng , Nör Jacques E.
Published: April 2023

Abstract
Members of the Bcl-2 family play a major role in the pathobiology of head and neck cancer. We have shown that Bcl-2 orchestrates a cross talk between tumor cells and endothelial cells that have a direct effect on the progression of head and neck squamous cell carcinoma (HNSCC). Notably, Bcl-2 is significantly up-regulated in the tumor-associated endothelial cells compared with the endothelial cells of normal oral mucosa in patients with HNSCC. Here, we evaluated the effect of TW-37, a small-molecule inhibitor of Bcl-2, on the cell cycle and survival of endothelial cells and HNSCC and on the progression of xenografted tumors. TW-37 has an IC50 of 1.1 μmol/L for primary human endothelial cells and averaged 0.3 μmol/L for head and neck cancer cells (OSCC3, UM-SCC-1, and UM-SCC-74A). The combination of TW-37 and cisplatin showed enhanced cytotoxic effects for endothelial cells and HNSCC in vitro, compared with single drug treatment. Notably, whereas cisplatin led to an expected G2-M cell cycle arrest, TW-37 mediated an S-phase cell cycle arrest in endothelial cells and in HNSCC. In vivo, TW-37 inhibited tumor angiogenesis and induced tumor apoptosis without significant systemic toxicities. Combination of TW-37 and cisplatin enhanced the time to tumor failure (i.e., 4-fold increase in tumor volume), compared with either drug given separately. Collectively, these data reveal that therapeutic inhibition of Bcl-2 function with TW-37 is sufficient to arrest endothelial cells and HNSCC in the S phase of the cell cycle and to inhibit head and neck tumor angiogenesis.[Mol Cancer Ther 2009;8(4):893–903]
Data from 1,25-Dihydroxyvitamin D3 Enhances the Apoptotic Activity of MDM2 Antagonist Nutlin-3a in Acute Myeloid Leukemia Cells Expressing Wild-type p53
Authors: Thompson Thelma , Andreeff Michael , Studzinski George P. , Vassilev Lyubomir T.
Published: April 2023

Abstract
The tumor suppressor p53 is often referred to as “the guardian of the genome” because of its central role in the cellular response to oncogenic stress and prevention of tumor development. Mutations of p53 in acute myeloid leukemia (AML) are rare but resistance to chemotherapy has been reported because of the deregulation of the p53 signaling and differentiation pathways. It is known that the interaction of the vitamin D metabolite 1,25-dihydroxyvitamin D3 (1,25D) with its functional vitamin D receptor leads to differentiation, G1 arrest, and increased cell survival in p53-null AML cells. However, there are no reports on the effect of 1,25D in leukemia cells expressing wild-type p53. Here, we examine vitamin D signaling in AML cells MOLM-13 and OCI-AML3 expressing wild-type p53 in the presence and absence of the MDM2 antagonist nutlin-3. We find that 1,25D alone induces monocytic differentiation in these cell lines similar to that seen in p53-null AML cells, suggesting that the presence of wild-type p53 is compatible with activation of vitamin D signaling. Combination of nutlin-3a with 1,25D accelerated programmed cell death, likely because of enhanced nutlin-induced upregulation of the proapoptotic PIG-6 protein and downregulation of antiapoptotic BCL-2, MDMX, human kinase suppressor of Ras 2, and phosphorylated extracellular signal-regulated kinase 2. Mol Cancer Ther; 9(5); 1158–68. ©2010 AACR.
Data from p27Kip1 expression inhibits glioblastoma growth, invasion, and tumor-induced neoangiogenesis
Authors: Schiappacassi Monica , Lovat Francesca , Canzonieri Vincenzo , Belletti Barbara , Berton Stefania , Di Stefano Domenica , Vecchione Andrea , Colombatti Alfonso , Baldassarre Gustavo
Published: April 2023

Abstract
The tumor suppressor gene CDKN1B encodes for a 27-kDa cyclin-dependent kinase inhibitory protein, p27Kip1, which together with its well-established role in the inhibition of cell proliferation, displays additional activities in the control of gene transcription and cell motility. p27Kip1 thus represents a good candidate for a gene therapy approach, especially in those cancers refractory to the conventional therapies, like human glioblastoma. Here, we show that overexpression of p27Kip1 in glioblastoma cell lines induced cell cycle arrest and inhibition of cell motility through extracellular matrix substrates. The use of adenoviral vectors in the treatment of glioblastoma in vivo showed that p27Kip1 was able to block not only cancer cell growth but also local invasion and tumor-induced neoangiogenesis. The latter effect was due to the ability of p27 to impair both endothelial cell growth and motility, thus preventing proper vessel formation in the tumor. The block of neoangiogenesis depended on cytoplasmic p27Kip1 antimigratory activity and was linked to its ability to bind to and inhibit the microtubule-destabilizing protein stathmin. Our work provides the first evidence that a successful p27Kip1-based gene therapy is linked to tumor microenvironment modification, thus opening new perspectives to the use of gene therapy approaches for the treatment of refractory cancers. [Mol Cancer Ther 2008;7(5):1164–75]
Data from Three-kinase inhibitor combination recreates multipathway effects of a geldanamycin analogue on hepatocellular carcinoma cell death
Authors: Pritchard Justin R. , Cosgrove Benjamin D. , Hemann Michael T. , Griffith Linda G. , Wands Jack R. , Lauffenburger Douglas A.
Published: April 2023

Abstract
Multitarget compounds that act on a diverse set of regulatory pathways are emerging as a therapeutic approach for a variety of cancers. Toward a more specified use of this approach, we hypothesize that the desired efficacy can be recreated in terms of a particular combination of relatively more specific (i.e., ostensibly single target) compounds. We test this hypothesis for the geldanamycin analogue 17-Allylamino-17-demethoxygeldanamycin (17AAG) in hepatocellular carcinoma cells, measuring critical phosphorylation levels that indicate the kinase pathway effects correlating with apoptotic responsiveness of the Hep3B cell line in contrast to the apoptotic resistance of the Huh7 cell line. A principal components analysis (PCA) constructed from time course measurements of seven phosphoprotein signaling levels identified modulation of the AKT, IκB kinase, and signal transducer and activator of transcription 3 pathways by 17AAG treatment as most important for distinguishing these cell-specific death responses. The analysis correctly suggested from 17AAG-induced effects on these phosphoprotein levels that the FOCUS cell line would show apoptotic responsiveness similarly to Hep3B. The PCA also guided the inhibition of three critical pathways and rendered Huh7 cells responsive to 17AAG. Strikingly, in all three hepatocellular carcinoma lines, the three-inhibitor combination alone exhibited similar or greater efficacy to 17AAG. We conclude that (a) the PCA captures and clusters the multipathway phosphoprotein time courses with respect to their 17AAG-induced apoptotic responsiveness and (b) we can recreate, in a more specified manner, the cellular responses of a prospective multitarget cancer therapeutic. [Mol Cancer Ther 2009;8(8):2183–92]
Data from Folate-mediated intracellular drug delivery increases the anticancer efficacy of nanoparticulate formulation of arsenic trioxide
Authors: Chen Haimei , Ahn Richard , Van den Bossche Jeroen , Thompson David H. , O'Halloran Thomas V.
Published: April 2023

Abstract
Arsenic trioxide (As2O3) is a frontline drug for treatment of acute promyelocytic leukemia and is in clinical trials for treatment of other malignancies, including multiple myeloma; however, efforts to expand clinical utility to solid tumors have been limited by toxicity. Nanoparticulate forms of As2O3 encapsulated in 100-nm-scale, folate-targeted liposomes have been developed to lower systematic toxicity and provide a platform for targeting this agent. The resultant arsenic “nanobins” are stable under physiologic conditions but undergo triggered drug release when the pH is lowered to endosomal/lysosomal levels. Cellular uptake and antitumor efficacy of these arsenic liposomes have been evaluated in folate receptor (FR)–positive human nasopharyngeal (KB) and cervix (HeLa) cells, as well as FR-negative human breast (MCF-7) tumor cells through confocal microscopy, inductively coupled plasma mass spectroscopy, and cytotoxicity studies. Uptake of folate-targeted liposomal arsenic by KB cells was three to six times higher than that of free As2O3 or nontargeted liposomal arsenic; the enhanced uptake occurs through folate-mediated endocytosis, leading to a 28-fold increase in cytotoxicity. In contrast, tumor cells with lower FR density on the surface (HeLa and MCF-7) showed much less uptake of the folate-targeted drug and lower efficacy. In cocultures of KB and MCF-7 cells, the folate-targeted arsenic liposomes were exclusively internalized by KB cells, showing high targeting specificity. Our studies further indicate that folate-targeted delivery of As2O3 with coencapsulated nickel(II) ions (as a nontoxic adjuvant) potentiates the As2O3 efficacy in relatively insensitive solid tumor–derived cells and holds the promise of improving drug therapeutic index. [Mol Cancer Ther 2009;8(7):1955–63]
Data from Correcting miR-15a/16 genetic defect in New Zealand Black mouse model of CLL enhances drug sensitivity
Authors: Salerno Erica , Scaglione Brian J. , Coffman Frederick D. , Brown Brian D. , Baccarini Alessia , Fernandes Helen , Marti Gerald , Raveche Elizabeth S.
Published: April 2023

Abstract
Alterations in the human 13q14 genomic region containing microRNAs mir-15a and mir-16-1 are present in most human chronic lymphocytic leukemia (CLL). We have previously found the development of CLL in the New Zealand Black murine model to be associated with a point mutation in the primary mir-15a/16-1 region, which correlated with a decrease in mature miR-16 and miR-15a levels. In this study, addition of exogenous miR-15a and miR-16 led to an accumulation of cells in G1 in non–New Zealand Black B cell and New Zealand Black–derived malignant B-1 cell lines. However, the New Zealand Black line had significantly greater G1 accumulation, suggesting a restoration of cell cycle control upon exogenous miR-15a/16 addition. Our experiments showed a reduction in protein levels of cyclin D1, a miR-15a/16 target and cell cycle regulator of G1/S transition, in the New Zealand Black cell line following miR-15a/16 addition. These microRNAs were shown to directly target the cyclin D1 3′ untranslated region using a green fluorescent protein lentiviral expression system. miR-16 was also shown to augment apoptosis induction by nutlin, a mouse double minute 2 (MDM2) antagonist, and genistein, a tyrosine kinase inhibitor, when added to a B-1 cell line derived from multiple in vivo passages of malignant B-1 cells from New Zealand Black mice with CLL. miR-16 synergized with nutlin and genistein to induce apoptosis. Our data support a role for the mir-15a/16-1 cluster in cell cycle regulation and suggest that these mature microRNAs in both the New Zealand Black model and human CLL may be targets for therapeutic efficacy in this disease. [Mol Cancer Ther 2009;8(9):2684–92]
Data from Reovirus Virotherapy Overrides Tumor Antigen Presentation Evasion and Promotes Protective Antitumor Immunity
Authors: Gujar Shashi A. , Marcato Paola , Pan Da , Lee Patrick W.K.
Published: April 2023

Abstract
Tumor-associated immunosuppressive strategies, such as lack of tumor antigen recognition and failure of lymphocyte activation and homing, resist the development of tumor-specific immunity and hamper the immune response–mediated elimination of cancerous cells. In this report, we show that reovirus virotherapy overrides such a tumor immune evasion and establishes clinically meaningful antitumor immunity capable of protecting against subsequent tumor challenge. Reovirus-mediated destruction of tumor cells facilitates the recognition of tumor antigens by promoting the display of otherwise inaccessible tumor-specific immunogenic peptides on the surface of dendritic cells (DC). Furthermore, on exposure to reovirus, DCs produce IL-1α, IL-1β, IL-6, IL-12p40/70, IL-17, CD30L, eotaxin, GM-CSF, KC, MCP-1, MCP-5, M-CSF, MIG, MIP-1α, RANTES, TNF-α, VCAM-1, VSGF, CXCL-16, AXL, and MCP-2; undergo maturation; and migrate into the tumor microenvironment along with CD8 T cells. These reovirus-activated DCs also acquire the capacity to prime tumor antigen–specific transgenic T cells in vitro and intrinsic antitumor T-cell response in vivo. Further, reovirus virotherapy augments the efficacy of DC- or T cell–based anticancer immunotherapies and synergistically enhances the survival in tumor-bearing mice. Most importantly, antitumor cellular immune responses initiated during reovirus oncotherapy protect the host against subsequent tumor challenge in a reovirus-independent but antigen-dependent manner. These reovirus oncotherapy–initiated antitumor immune responses represent an anticancer therapeutic entity that can maintain a long-term cancer-free health even after discontinuation of therapy. Mol Cancer Ther; 9(11); 2924–33. ©2010 AACR.
Data from Molecular imaging of Bcr-Abl phosphokinase in a xenograft model
Authors: Wu Ji Yuan , Yang David J. , Angelo Laura S. , Kohanim Saady , Kurzrock Razelle
Published: April 2023

Abstract
The purpose of this study was to determine whether the Bcr-Abl tyrosine kinase can be assessed by γ-imaging using an 111In-labeled anti-phosphotyrosine (APT) antibody, and if the response to treatment with imatinib could be detected using this imaging technique. APT antibody was labeled with 111In using ethylenedicysteine (EC) as a chelator. To determine if 111In-EC-APT could assess a nonreceptor tyrosine kinase, xenografts of the human chronic myelogenous leukemia cell line K562 were used. γ-Scintigraphy of the tumor-bearing mice, before and after imatinib treatment, was obtained 1, 24, and 48 h after they were given 111In-EC-APT (100 μCi/mouse i.v.). 111In-EC-APT is preferentially taken up by Bcr-Abl-bearing tumor cells when compared with 111In-EC-BSA or 111In-EC-IgG1 controls and comparable with the level of uptake of 111In-EC-Bcr-Abl. Imatinib treatment resulted in decreased expression of phospho-Bcr-Abl by Western blot analysis, which correlated with early (4 days after starting imatinib) kinase down-regulation as assessed by imaging using 111In-EC-APT. The optimal time to imaging was 24 and 48 h after injection of 111In-EC-APT. Although tumor regression was insignificant on day 4 after starting imatinib treatment, it was marked by day 14. 111In-EC-APT can assess intracellular phosphokinase activity, and down-regulation of phosphokinase activity predates tumor regression. This technique may therefore be useful in the clinic to detect the presence of phosphokinase activity and for early prediction of response. [Mol Cancer Ther 2009;8(3):703–10]
Data from MDA-7/IL-24–induced cell killing in malignant renal carcinoma cells occurs by a ceramide/CD95/PERK–dependent mechanism
Authors: Park Margaret A. , Walker Teneille , Martin Aditi Pandya , Allegood Jeremy , Vozhilla Nicollaq , Emdad Luni , Sarkar Devanand , Rahmani Mohammed , Graf Martin , Yacoub Adly , Koumenis Costas , Spiegel Sarah , Curiel David T. , Voelkel-Johnson Christina , Grant Steven , Fisher Paul B. , Dent Paul
Published: April 2023

Abstract
Melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24) is a novel cytokine displaying selective apoptosis-inducing activity in transformed cells without harming normal cells. The present studies focused on clarifying the mechanism(s) by which glutathione S-transferase (GST)-MDA-7 altered cell survival of human renal carcinoma cells in vitro. GST-MDA-7 caused plasma membrane clustering of CD95 and the association of CD95 with procaspase-8. GST-MDA-7 lethality was suppressed by inhibition of caspase-8 or by overexpression of short-form cellular FLICE inhibitory protein, but only weakly by inhibition of cathepsin proteases. GST-MDA-7–induced CD95 clustering (and apoptosis) was blocked by knockdown of acidic sphingomyelinase or, to a greater extent, ceramide synthase-6 expression. GST-MDA-7 killing was, in parallel, dependent on inactivation of extracellular signal–regulated kinase 1/2 and on CD95-induced p38 mitogen-activated protein kinase and c-jun NH2-terminal kinase-1/2 signaling. Knockdown of CD95 expression abolished GST-MDA-7–induced phosphorylation of protein kinase R–like endoplasmic reticulum kinase. GST-MDA-7 lethality was suppressed by knockout or expression of a dominant negative protein kinase R–like endoplasmic reticulum kinase that correlated with reduced c-jun NH2-terminal kinase-1/2 and p38 mitogen-activated protein kinase signaling and maintained extracellular signal–regulated kinase-1/2 phosphorylation. GST-MDA-7 caused vacuolization of LC3 through a mechanism that was largely CD95 dependent and whose formation was suppressed by knockdown of ATG5 expression. Knockdown of ATG5 suppressed GST-MDA-7 toxicity. Our data show that in kidney cancer cells GST-MDA-7 induces ceramide-dependent activation of CD95, which is causal in promoting an endoplasmic reticulum stress response that activates multiple proapoptotic pathways to decrease survival.[Mol Cancer Ther 2009;8(5):OF1–12]
Data from Reactivation of p53 by a specific MDM2 antagonist (MI-43) leads to p21-mediated cell cycle arrest and selective cell death in colon cancer
Authors: Shangary Sanjeev , Ding Ke , Qiu Su , Nikolovska-Coleska Zaneta , Bauer Joshua A. , Liu Meilan , Wang Guoping , Lu Yipin , McEachern Donna , Bernard Denzil , Bradford Carol R. , Carey Thomas E. , Wang Shaomeng
Published: April 2023

Abstract
MDM2 oncoprotein binds directly to the p53 tumor suppressor and inhibits its function in cancers retaining wild-type p53. Blocking this interaction using small molecules is a promising approach to reactivate p53 function and is being pursued as a new anticancer strategy. The spiro-oxindole MI-43, a small-molecule inhibitor of the MDM2-p53 interaction, was designed and examined for its cellular mechanism of action and therapeutic potential in colon cancer. MI-43 binds to MDM2 protein with a Ki value of 18 nmol/L and is 300 times more potent than a native p53 peptide. MI-43 blocks the intracellular MDM2-p53 interaction and induces p53 accumulation in both normal and cancer cells, with wild-type p53 without causing p53 phosphorylation. Induction of p53 leads to modulation of the expression of p53 target genes, including up-regulation of p21 and MDM2 in normal primary human cells and in colon cancer cells with wild-type p53. Using HCT-116 isogenic colon cancer cell lines differing only in p53 status or RNA interference to knockdown expression of p53 in the RKO colon cancer cell line, we show that the cell growth inhibition and cell death induction by MI-43 is p53 dependent. Furthermore, induction of cell cycle arrest by MI-43 is dependent on p53 and p21. In normal cells, MI-43 induces cell cycle arrest but not apoptosis. This study suggests that p53 activation by a potent and specific spiro-oxindole MDM2 antagonist may represent a promising therapeutic strategy for the treatment of colon cancer and should be further evaluated in vivo and in the clinic. [Mol Cancer Ther 2008;7(6):1533–42]
Data from Ligand-Specific Antibodies to Insulin-Like Growth Factors Suppress Intestinal Polyp Formation in Apc+/− Mice
Authors: Matsunaka Toshihiro , Miyamoto Shin'ichi , Shitara Kenya , Ochiai Atsushi , Chiba Tsutomu
Published: April 2023

Abstract
Insulin-like growth factors (IGF-I and IGF-II) play important roles in intestinal tumorigenesis. To investigate the effectiveness of IGF-targeting strategies, we conducted an in vivo study using anti-mouse neutralizing antibodies IGF-I (KM3168) and IGF-II (KM1468). Six- and 10-week-old Apc+/− mice were given KM3168 and/or KM1468 i.p. at two doses (0.01 or 0.1 μg/g weight) once or twice weekly for 4 weeks. To clarify the source of IGFs in vivo, we evaluated the expression levels of IGFs in the liver, normal small intestine, and polyps of the small intestine of Apc+/− mice. The phosphorylation status of IGF signal–related molecules was examined using immunostaining to understand the mechanism underlying the effects of IGF-neutralizing antibody. The plasma half-life was 168 for KM3168 and 85 hours for KM1468. In two lineages of Apc+/− mice (Apc1309 and ApcMin/+), a low dose (0.01 μg/g weight) of KM3168 and KM1468 significantly reduced the number of polyps when given once and twice weekly, respectively. Combined administration of the effective dose of each antibody had an additive effect. The liver was the main source of IGF-I, whereas the polyps of the small intestine and normal small intestine were the main source of IGF-II. IGF-neutralizing antibodies decreased the phosphorylation of IGF type 1 receptor and inhibited the signal transduction of the Akt pathway. These results suggest that IGF-I and IGF-II play important roles in polyp formation in Apc+/− mice and that specific antibodies to IGF-I and IGF-II may be promising antitumor agents. Mol Cancer Ther; 9(2); 419–28
Data from Stage 2 Combination Testing of Rapamycin with Cytotoxic Agents by the Pediatric Preclinical Testing Program
Authors: Houghton Peter J. , Morton Christopher L. , Gorlick Richard , Lock Richard B. , Carol Hernan , Reynolds C. Patrick , Kang Min H. , Maris John M. , Keir Stephen T. , Kolb E. Anders , Wu Jianrong , Wozniak Amy W. , Billups Catherine A. , Rubinstein Larry , Smith Malcolm A.
Published: April 2023

Abstract
Rapamycin demonstrated broad-spectrum tumor growth inhibition activity against the in vivo panels of childhood tumors used in the Pediatric Preclinical Testing Program (PPTP). Here we have evaluated rapamycin combined with agents used frequently in the treatment of childhood malignancies. Rapamycin was tested in vitro against 23 cell lines alone or in combination with melphalan, cisplatin, vincristine, or dexamethasone (leukemic models only). In vivo, the impact of combining rapamycin with a cytotoxic agent was evaluated using two measures: 1) the therapeutic enhancement measure, and 2) a linear regression model for time-to-event to formally evaluate for sub- and supraadditivity for the combination compared to the agents used alone. Combining rapamycin with cytotoxic agents in vitro gave predominantly subadditive or additive effects, except for dexamethasone in leukemia models for which supra-additive activity was observed. In vivo testing demonstrated that therapeutic enhancement was common for rapamycin in combination with cyclophosphamide and occurred for 4 of 11 evaluable xenografts for the rapamycin and vincristine combination. The combinations of rapamycin with either cyclophosphamide or vincristine were significantly more effective than the respective standard agents used alone at their maximum tolerated doses (MTD) for most evaluable xenografts. The combination of rapamycin and cisplatin produced excessive toxicity requiring cisplatin dose reductions, and therapeutic enhancement was not observed for this combination. Addition of rapamycin to either cyclophosphamide or vincristine at their respective MTDs appears promising, as these combinations are relatively well tolerated and as many of the pediatric preclinical models evaluated demonstrated therapeutic enhancement for these combinations. Mol Cancer Ther; 9(1); 101–12
Data from Simultaneous blockade of the epidermal growth factor receptor/mammalian target of rapamycin pathway by epidermal growth factor receptor inhibitors and rapamycin results in reduced cell growth and survival in biliary tract cancer cells
Authors: Herberger Beata , Berger Walter , Puhalla Harald , Schmid Katharina , Novak Sabine , Brandstetter Anita , Pirker Christine , Gruenberger Thomas , Filipits Martin
Published: April 2023

Abstract
The prognosis of patients with biliary tract adenocarcinomas (BTA) is still poor due to lack of effective systemic treatment options. Knowledge of the molecular mechanisms involved in the pathogenesis of this disease is of importance for the development of new treatment strategies. We determined the expression of epidermal growth factor receptor (EGFR) and activated mammalian target of rapamycin (p-mTOR) in paraffin-embedded surgical specimens of BTA (n = 89) by immunohistochemistry. Overall survival was analyzed with Cox models adjusted for clinical and pathologic factors. Combined EGFR/p-mTOR expression was significantly associated with relapse-free survival [adjusted hazard ratio for relapse, 2.20; 95% confidence interval (95% CI), 1.45-3.33; P < 0.001] and overall survival (adjusted hazard ratio for death, 2.32; 95% CI, 1.50-3.58; P < 0.001) of the patients. The effect of the EGFR inhibitors erlotinib or cetuximab and the mTOR inhibitor rapamycin on growth and survival of five BTA cell lines was tested in short-term 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays and long-term colony formation assays. Simultaneous blockade of EGFR and mTOR in biliary tract cancer cell lines results in a synergistic inhibition of both phosphatidylinositol-3-kinase and mitogen-activated protein kinase pathways, leading to reduced cell growth and survival. These results suggest that combined targeted therapy with EGFR and mTOR inhibitors may potentially benefit patients with BTAs and should be further evaluated in clinical trials. [Mol Cancer Ther 2009;8(6):1547–56]
Data from Potent synergy of dual antitumor peptides for growth suppression of human glioblastoma cell lines
Authors: Kondo Eisaku , Tanaka Takehiro , Miyake Takayoshi , Ichikawa Tomotsugu , Hirai Masahiko , Adachi Masaki , Yoshikawa Kazuhiro , Ichimura Koichi , Ohara Nobuya , Moriwaki Akiyoshi , Date Isao , Ueda Ryuzo , Yoshino Tadashi
Published: April 2023

Abstract
Molecular targeting agents have become formidable anticancer weapons, which show much promise against the refractory tumors. Functional peptides are among the more desirable of these nanobio-tools. Intracellular delivery of multiple functional peptides forms a basis for potent, non-invasive mode of delivery, providing distinctive therapeutic advantages. Here, we examine growth suppression efficiency of human glioblastomas by dual-peptide targeting. We did simultaneous introduction of two tumor suppressor peptides (p14ARF and p16INK4a or p16INK4a and p21CIP1 functional peptides) compared with single-peptide introduction using Wr-T-mediated peptide delivery. Wr-T-mediated transport of both p14ARF and p16INK4a functional peptides (p14-1C and p16-MIS, respectively) into human glioblastoma cell line, U87ΔEGFR, reversed specific loss of p14 and p16 function, thereby drastically inhibiting tumor growth by >95% within the first 72 h, whereas the growth inhibition was ∼40% by p14 or p16 single-peptide introduction. Additionally, the combination of p16 and p21CIP1 (p21-S154A) peptides dramatically suppressed the growth of glioblastoma line Gli36ΔEGFR, which carries a missense mutation in p53, by >97% after 120 h. Significantly, our murine brain tumor model for dual-peptide delivery showed a substantial average survival enhancement (P < 0.0001) for peptide-treated mice. Wr-T-mediated dual molecular targeting using antitumor peptides is highly effective against growth of aggressive glioblastoma cells in comparison with single molecule targeting. Thus, jointly restoring multiple tumor suppressor functions by Wr-T-peptide delivery represents a powerful approach, with mechanistic implications for development of efficacious molecular targeting therapeutics against intractable human malignancies. [Mol Cancer Ther 2008;7(6):1461–71]
Data from 2-Methoxyestradiol Inhibits Barrett's Esophageal Adenocarcinoma Growth and Differentiation through Differential Regulation of the β-Catenin–E-Cadherin Axis
Authors: Kambhampati Suman , Banerjee Snigdha , Dhar Kakali , Mehta Smita , Haque Inamul , Dhar Gopal , Majumder Monami , Ray Gibanananda , Vanveldhuizen Peter J. , Banerjee Sushanta K.
Published: April 2023

Abstract
The purpose of this study was to evaluate whether 2-methoxyestradiol (2-ME2), a promising anticancer agent, modulates Barrett's esophageal adenocarcinoma (BEAC) cell growth and behavior through a cellular pathway involving β-catenin in partnership with E-cadherin, which seems to play a critical role in the induction of antitumor responses in cancer cells. We found that 2-ME2 markedly reduced the BEAC cell proliferation through regulating apoptotic machinery such as Bcl-2 and Bax. It may nullify the aggressive behavior of the cells by reducing the migratory behavior. Expressions of β-catenin and E-cadherin and binding of these two proteins is activated in a 2-ME2–dependent fashion in Bic-1 cells. Moreover, overexpressions of these two proteins may be due to the stabilization of these proteins by 2-ME2. We found that 2-ME2–induced antimigratory effects are mediated through the β-catenin–E-cadherin signaling pathways. In view of these results, we determined whether 2-ME2 reduces BEAC tumor growth. Administration of 2-ME2 significantly decreased the growth of BEAC cells xenografted on the flank of nude mice. The evidence presented points out that the effect of 2-ME2 on β-catenin–orchestrated signal transduction plausibly plays a multifaceted functional role to inhibit the proliferation and cell migration of 2-ME2–treated malignant cells and it could be a potential candidate in novel treatment strategies for Barrett's esophageal adenocarcinoma. Mol Cancer Ther; 9(3); 523–34
Data from Involvement of microRNA-451 in resistance of the MCF-7 breast cancer cells to chemotherapeutic drug doxorubicin
Authors: Kovalchuk Olga , Filkowski Jody , Meservy James , Ilnytskyy Yaroslav , Tryndyak Volodymyr P. , Chekhun Vasyl' F. , Pogribny Igor P.
Published: April 2023

Abstract
Many chemotherapy regiments are successfully used to treat breast cancer; however, often breast cancer cells develop drug resistance that usually leads to a relapse and worsening of prognosis. We have shown recently that epigenetic changes such as DNA methylation and histone modifications play an important role in breast cancer cell resistance to chemotherapeutic agents. Another mechanism of gene expression control is mediated via the function of small regulatory RNA, particularly microRNA (miRNA); its role in cancer cell drug resistance still remains unexplored. In the present study, we investigated the role of miRNA in the resistance of human MCF-7 breast adenocarcinoma cells to doxorubicin (DOX). Here, we for the first time show that DOX-resistant MCF-7 cells (MCF-7/DOX) exhibit a considerable dysregulation of the miRNAome profile and altered expression of miRNA processing enzymes Dicer and Argonaute 2. The mechanistic link of miRNAome deregulation and the multidrug-resistant phenotype of MCF-7/DOX cells was evidenced by a remarkable correlation between specific miRNA expression and corresponding changes in protein levels of their targets, specifically those ones that have a documented role in cancer drug resistance. Furthermore, we show that microRNA-451 regulates the expression of multidrug resistance 1 gene. More importantly, transfection of the MCF-7/DOX-resistant cells with microRNA-451 resulted in the increased sensitivity of cells to DOX, indicating that correction of altered expression of miRNA may have significant implications for therapeutic strategies aiming to overcome cancer cell resistance. [Mol Cancer Ther 2008;7(7):2152–9]