scholarly journals PRIMA-1met Induces Autophagy in Colorectal Cancer Cells With Different p53 Status

2020 ◽  
Author(s):  
Xiao-lan Li ◽  
Jianbiao Zhou ◽  
Chen-jing Xia ◽  
Zhong-kai Lu ◽  
Zhi-rong Chen
Keyword(s):  
Colorectal Cancer ◽  
Cell Lines ◽  
Inhibitory Effect ◽  
Cell Counting ◽  
Signaling Cascade ◽  
Mutant P53 ◽  
Wild Type ◽  
P53 Status ◽  
Wild Type P53 ◽  
In Cells

Abstract Background: PRIMA-1met (APR246), a methylated form of PRIMA-1 (p53-reactivation and induction of massive apoptosis-1, APR-017), targets mutant p53 for restoring its wild-type structure and function. We previously demonstrated that PRIMA-1met was efficient in suppressing the growth of colorectal cancer (CRC) cells in a p53-independent manner, and distinctly induced apoptosis mediated by up-regulation of Noxa in p53-mutant cell lines. Here we aimed to the effect of PRIMA-1met on autophagy in different CRC cell lines, to further investigate mechanisms underlying the inhibitory effect in cells with different p53 status.Methods: 3 CRC cell lines with wild-type p53, 5 lines with mutant p53 and 1 line without p53 were obtained for this study. Using western blotting, acridine orange staining, and transmission electron microscopy detection, we assessed autophagy flux in different cells treated with PRIMA-1met, and detected expression of mTOR/AMPK-ULK1-Vps34 autophagic signaling cascade. We also evaluated cell proliferation of cells with PRIMA-1met treatment by cell counting Kit-8 proliferation assay, compared to combination of PRIAM-1met and 3-Methyladenine. Furthermore, we knocked down Noxa gene by siRNA in different CRC cells, to assess LC3 conversion after administration of PRIMA-1met. Values were expressed as mean + standard error of the mean. Comparison between groups of data was made using one-way analysis of variance.Results: In this study, we showed that PRIMA-1met induced autophagy in CRC cells independent on p53 status. PRIMA-1met not only promoted autophagic vesicles (AVs) formation and AV-lysosome fusion, but also increased lysosomal degradation. Mechanistically, activation of mTOR/AMPK-ULK1-Vps34 autophagic signaling cascade was important for PRIMA-1met-induced autophagy. Furthermore, autophagy played a crucial role in the inhibitory effect of PRIMA-1met only in cells harboring wild-type p53, which was closely related to the increased Noxa.Conclusions: Our results indicated that PRIMA-1met induced autophagy in CRC cells regardless of p53 status via activating mTOR/AMPK-ULK1-Vps34 signaling cascade. However, induced autophagy was relevant to the cytotoxicity of PRIMA-1met in cells carrying wild-type p53, along with up-regulation of Noxa. Implying that, PRIMA-1met-based therapy could be an effective strategy for CRC.Trail registration: Not applicable.

Tumor Suppressor Microrna-29a/b and Microrna-34a Mediate Small Molecule PRIMA-1Met-Induced Aoptosis In Multiple Myeloma Cells By Targeting c-Myc

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1919-1919
Author(s):  
Manujendra N. Saha ◽  
Yijun Yang ◽  
Hong Chang
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Mutant P53 ◽  
Pcr Array ◽  
Wild Type ◽  
Down Regulation ◽  
Over Expression ◽  
P53 Status ◽  
Low Expression

Abstract PRIMA-1Met/APR246 (p53 reactivation and induction of massive apoptosis), is a small molecule with remarkable anti-tumor activities in various human tumor cells, and is currently under phase I/II clinical trial. We have previously demonstrated anti-tumor activity of PRIMA-1Met in multiple myeloma (MM) cells irrespective of p53 status. In addition, we have shown that PRIMA-1Met alone or in combination with dexamethasone triggers significant tumor growth inhibition in vivo in a murine xenograft model of human MM. However, the molecular mechanism underlying anti-myeloma activity of PRIMA-1Met has not been fully elucidated. MicroRNAs (miRNAs) are non-coding small RNA molecules that regulate post-transcriptional gene expression and play a critical role in tumor pathogenesis. Since the role of miRNAs and their regulation in response to PRIMA-1Met in MM is not known, here we investigated the relationship between PRIMA-1Met-induced apoptosis and miRNA expression in MM cells. Using a miRNA PCR array platform (Human Cancer Pathway Finder miScript miRNA PCR array, MIHS-102Z, Qiagen Inc), we analyzed the miRNA profiles in two MM cell lines of different p53 status (MM.1S with wild type p53 and 8226 with mutant p53) treated with either PRIMA-1Met or DMSO control. After normalization to a set of housekeeping genes, differential expressions of the miRNAs were analysed. miRNA-29a, miRNA-29b, and miRNA-34a were found significantly up-regulated (more than 2 fold, p<0.05) in cells treated with PRIMA-1Met compared to DMSO-treated cells. To evaluate the effect of over-expression of these miRNAs, we transfected two MM cell lines (MM.1S and 8226) with either miR-29a/b or miR-34a. Cells transfected with scramble miRNA were used as control. Over-expression of the miRNAs resulted in a dose-dependent inhibition of viability and increase in apoptosis of MM.1S or 8226 cells. Next, we examined the endogenous expression of these miRNAs in 5 primary MM samples by qPCR. Results showed a significant low expression of miR-29a/b and miR-34a in 3 of the 5 samples. Treatment of the two primary MM samples with low expression for miR-29a/b and miR-34a with PRIMA-1Met resulted in up-regulation of these miRNAs leading to inhibition of the viability and induction of apoptosis. To identify the possible targets of these miRNAs, we performed bioinformatics analysis. Results obtained from different searches by miRanda and TargetScan algorithm predicted c-Myc as a potential target for miRNA-29a/b and miRNA-34a. c-Myc is an oncogene whose over-expression has been associated with resistance to current chemotherapy in MM. Global gene expression profiling by microarray showed significant down-regulation of c-Myc in two MM cell lines with either wild type or mutant p53 treated with PRIMA-1Met compare to cells treated with DMSO. Importantly, down-regulation of c-Myc (∼2.6-fold) by PRIMA-1Met was also observed in a MM cell line (8226R5) lacking p53 expression suggesting an important role of c-Myc in p53-independent apoptosis of MM cells induced by PRIMA-1Met. By qPCR and Western blot analysis, we confirmed significant down-regulation of c-Myc in PRIMA-1Met-treated MM cells. These data provided the evidence for an inverse correlation between the expression of these miRNAs and c-Myc indicating that apoptosis of MM cells induced by PRIMA-1Met is regulated by miRNAs29a/b or miRNA34a targeting c-Myc. Our results suggest a novel mechanism for PRIMA-1Met-induced apoptotic signaling in MM cells mediated by up-regulation of miR-29a/b and miR-34a targeting c-Myc. Our findings also provide a preclinical framework for development of therapeutic strategies in combination of PRIMA-1Met and miRNA (miR-29a/b or miR-34a) mimics for the treatment of MM patients, especially for those with high c-Myc expressions. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Targeting Aggregation of Wilde-Type p53 and Mutant p53 with ReACp53 As a Novel Therapeutic Concept for AML

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3944-3944 ◽  
Author(s):  
Jianfang Zeng ◽  
Alice Soragni ◽  
Jo Ishizawa ◽  
Vivian Ruvolo ◽  
Christopher B. Benton ◽  
...  
Keyword(s):  
Cell Lines ◽  
Term Treatment ◽  
Mutant P53 ◽  
Amyloid Aggregation ◽  
Wild Type ◽  
Short Term ◽  
Short Term Treatment ◽  
P53 Expression ◽  
Hematopoietic Malignancies ◽  
Wild Type P53

Abstract Background: The tumor suppressor p53 is a master regulator of apoptosis, autophagy, cell cycle, and senescence. It is inactivated via mutation in approximately 50% of solid tumors, but only in 15% of hematopoietic malignancies including acute myeloid leukemia (AML). A recently proposed mechanism has linked loss of p53 function with its amyloid aggregation. Conceptually, certain p53 mutations can favor partial unfolding of the protein and expose a natively buried aggregation-prone segment. This can result in amyloidogenic aggregation and prevent p53 transcriptional activity and anti-tumor functions. The cell-permeable peptide ReACp53, has been recently developed to block p53 aggregation and restore its transcriptional function in the nucleus as well as its ubiquitination by MDM2. ReACp53 showed significant cytotoxicity in ovarian cancer but no toxicity to normal hematopoietic cells in animal experiment. We sought to determine the anti-tumor activity of ReACp53 in hematopoietic malignancies. Results: We examined the p53 status in 23 malignant hematopoietic cell lines by PCR, Sanger sequencing, and immunoblotting. Two cell lines were null for p53 expression, one harbored frame shift mutations, 11 cell lines expressed various missense p53 mutations, one cell line had an in frame deletion of p53, and eight cell lines expressed wild-type p53. Additionally, immunofluorescence staining (IF) with the conformation-specific PAb240 antibody revealed high levels of cytoplasmic, partially unfolded p53 in the cells expressing mutant p53. In p53 wild-type cells, p53 protein was mainly localized in the nucleus and was negative for PAb240. The p53 null and frame shift-mutant cells showed no p53 expression. All the cells were treated short-term with various concentrations of ReACp53, or a scrambled peptide, and assessed for apoptosis by flow cytometry. We found that ReACp53 was cytotoxic not only to the p53-mutant cells, but also to the wild-type p53 lines. In fact, all p53 wild type AML cell lines were highly sensitive. The p53 negative cell lines were seemingly resistant to short-term exposure to ReACp53. DeltaNp73, an isoform of p73 that antagonizes p53 and TAp73, is expressed in most AML cells and also has a similar aggregation-prone segment. We examined the levels of DeltaNp73 and total p73 in 12 AML cell lines by PCR, immunoblotting, and IF. Both proteins were overexpressed in all five wild-type p53 cell lines, and DeltaNp73 was predominately localized in the cytoplasm of these cells. After short-term treatment with ReACp53, DeltaNp73 expression and localization didn't change in wild type p53 AML cells. Over-expressing DeltaNp73 in HEK293T cells enhanced their level of Thioflavin T staining indicating amyloid aggregation of the protein. Compared to controls, the DeltaNp73 overexpressing HEK293T cells were more prone to apoptosis following ReACp53 treatment. Absent of transactivation domain, DeltaNp73 is not expected to be restored to function like TAp73. Mutant p53 is known to cross-aggregate p73 and p63 because of their highly similar aggregation-prone segments, therefore, we hypothesize that DeltaNp73 cross-aggregated p53 and p73 and ReACp53 inhibited the aggregation as to restore p53 and TAp73 function and exposure to MDM2. We chose two wild-type p53 AML cell lines, OCI-AML3 and MOLM-14, which express MDM2 and are sensitive to the MDM2 inhibitor DS3032b. After short-term treatment with ReACp53, p53 and p73 (also a MDM2 target) expression decreased significantly in both cells. We tested the anti-leukemia efficacy of the DS3032b and ReACp53 combinatorial treatment in these cells and found that DS3032b synergized with ReACp53 to efficiently kill the cells compared to the cytotoxic activity of DS3032b or ReACp53 treatment alone. Conclusions: We demonstrate a new mechanism of DeltaNp73 inhibition of wild-type p53 and TAp73 mediated by induction of amyloid aggregation. ReACp53 showed apoptogenic efficacy in malignant hematopoietic cells, both in cells expressing wild-type p53 as well as mutant p53. In the wild-type AML cells where p73 and DeltaNp73 were overexpressed, sensitivity to ReACp53 increased. ReACp53 also exhibited synergistic activity when combined with the MDM2 inhibitor DS3032b in wild-type p53 cells. Together, our data suggest a novel mechanism of p53 inactivation by amyloid formation, that can be corrected in acute myeloid leukemia carrying either wild-type or mutant p53. Disclosures No relevant conflicts of interest to declare.

ONC201 Exerts p53-Independent Cytotoxicity Through TRAIL and DR5 Induction In Mantle Cell Lymphomas

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3822-3822
Author(s):  
Jo Ishizawa ◽  
Kensuke Kojima ◽  
Archana Dilip ◽  
Vivian R Ruvolo ◽  
Bing Z Carter ◽  
...  
Keyword(s):  
Cell Lines ◽  
Combination Index ◽  
Synergistic Effects ◽  
Pcr Analysis ◽  
Mutant P53 ◽  
Drug Resistant ◽  
Wild Type ◽  
Cytotoxic Effects ◽  
Wild Type P53 ◽  
Induced Apoptosis

Abstract ONC201 (TIC10) is a novel small molecule that induces TRAIL-dependent apoptosis in various cancer cell types and is under development to enter a first-in-man study in advanced cancer patients .It was identified in a screen for small molecules capable of up-regulating endogenous TRAIL gene transcription in a p53-independent manner (Allen JE et al, Sci Transl Med., 2013). ONC201 triggers FOXO3a activation through dual inhibition of ERK and AKT, which transcriptionally upregulates TRAIL and TNFRSF10B (TRAIL-R2/DR5) in solid tumors. Because PI3K/AKT and MEK/ERK activation have been shown to be major contributors to drug resistance, ONC201 is potentially promising since it not only promotes TRAIL activation, but also upregulates its pro-apoptotic receptor DR5. Here we report the anti-lymphoma effects of ONC201 in MCL, a presently incurable disease. We treated three human MCL cell lines with wild-type p53 (Z-138, JVM-2, and Granta-519) and two similar lines with mutant p53 (MINO and Jeko-1) with ONC201. A 72-hour ONC201 treatment induced apoptosis in all MCL cell lines. Surprisingly, the p53 mutant MINO and Jeko-1 cells were more susceptible in apoptosis assays to ONC201 than cells with wild-type p53 (Fig.1) The effective concentrations inducing cell killing (as measured by annexin V positivity) in 50%/75% of the cells in the Z-138, JVM-2, MINO, Jeko-1, and Granta-519 cells were 9.9/>10, >10/>10, 2.6/5.2, 2.7/4.6 and >10/ >10 micromolar, respectively. We also treated five primary human MCL samples (three with wild-type p53 and two with mutant p53), and found that one of the two mutant p53 samples was highly sensitive to ONC201 as were the three samples with wild-type p53. One mutant p53 sample that was less sensitive to ONC201, was also resistant to Nutlin-3a and Ibrutinib suggesting an extremely drug-resistant phenotype. Real-time PCR analysis revealed that both DR5 and TRAIL mRNAs were transcriptionally upregulated in the primary MCL samples (a relative ratio of 7.25 compared to 3.13 in controls) after 72-hour treatment with ONC201. To determine the significance of p53 functional status in ONC201-induced apoptosis, p53 wild-type Z-138 and JVM-2 cells were stably transduced with lentivirus encoding either negative control shRNA or p53-specific shRNA and were exposed to ONC201 and results demonstrated complete p53-independence. Normal human bone marrow cells and mesenchymal stem cells were completely resistant to the cytotoxic effects of ONC201, which illustrated this agent's low toxicity against normal tissues. In order to examine the role of p53 activation in ONC201-induced apoptosis in MCL cells, we combined ONC201 with the MDM2 inhibitor Nutlin-3a. The combination cytotoxic effects of this combination were synergistic in p53 wild-type Z-138 and JVM-2 cells (combination index 0.87 and 0.63, respectively). Similar synergistic effects of ONC201 combined with the BTK inhibitor Ibrutinib were observed in Z-138 and MINO cells (combination index 0.63 and 0.61, respectively). This combination also triggered synergistic apoptotic effects in two primary MCL samples with combination indexes of 0.0011 and 0.073, respectively. Conclusion ONC201 induces p53-independent apoptosis in MCL cells, and may have significant clinical impact by targeting both p53 wild type and p53 mutant drug-resistant MCL cells. ONC201 exerts synergistic effects with MDM2 and BTK inhibitors that may be explored clinically. Disclosures: Allen: Drug Company: Employment. Andreeff:Oncoceutics: SAB Other.

scholarly journals The Effect of Different Ester Chain Modifications of Two Guaianolides for Inhibition of Colorectal Cancer Cell Growth

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5481
Author(s):  
Lamis Al Aaraj ◽  
Berthe Hayar ◽  
Zaynab Jaber ◽  
Walid Saad ◽  
Najat A. Saliba ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Growth ◽  
Cancer Cell ◽  
Colorectal Cancer Cell ◽  
Colorectal Cancer Cell Line ◽  
Cancer Drug ◽  
Wild Type ◽  
Cancer Cell Growth ◽  
P53 Status ◽  
Wild Type P53

Several sesquiterpene lactones (STLs) have been tested as lead drugs in cancer clinical trials. Salograviolide-A (Sal-A) and salograviolide-B (Sal-B) are two STLs that have been isolated from Centaurea ainetensis, an indigenous medicinal plant of the Middle Eastern region. The parent compounds Sal-A and Sal-B were modified and successfully prepared into eight novel guaianolide-type STLs (compounds 1–8) bearing ester groups of different geometries. Sal-A, Sal-B, and compounds 1–8 were tested against a human colorectal cancer cell line model with differing p53 status; HCT116 with wild-type p53 and HCT116 p53−/− null for p53, and the normal-like human colon mucosa cells with wild-type p53, NCM460. IC50 values indicated that derivatization of Sal-A and Sal-B resulted in potentiation of HCT116 cell growth inhibition by 97% and 66%, respectively. The effects of the different molecules on cancer cell growth were independent of p53 status. Interestingly, the derivatization of Sal-A and Sal-B molecules enhanced their anti-growth properties versus 5-Fluorouracil (5-FU), which is the drug of choice in colorectal cancer. Structure-activity analysis revealed that the enhanced molecule potencies were mainly attributed to the position and number of the hydroxy groups, the lipophilicity, and the superiority of ester groups over hydroxy substituents in terms of their branching and chain lengths. The favorable cytotoxicity and selectivity of the potent molecules, to cancer cells versus their normal counterparts, pointed them out as promising leads for anti-cancer drug design.

Wild-type p53 restores cell cycle control and inhibits gene amplification in cells with mutant p53 alleles

Cell ◽  
1992 ◽  
Vol 70 (6) ◽  
pp. 937-948 ◽  
Author(s):  
Yuxin Yin ◽  
Michael A. Tainsky ◽  
Farideh Z. Bischoff ◽  
Louise C. Strong ◽  
Geoffrey M. Wahl
Keyword(s):  
Cell Cycle ◽  
Gene Amplification ◽  
Cell Cycle Control ◽  
Mutant P53 ◽  
Wild Type ◽  
Wild Type P53 ◽  
In Cells

Effects of clotrimazole on the growth, morphological characteristics, and cisplatin sensitivity of human glioblastoma cells in vitro

1999 ◽  
Vol 90 (5) ◽  
pp. 918-927 ◽  
Author(s):  
M. Humayun Khalid ◽  
Shobu Shibata ◽  
Tsuyoshi Hiura
Keyword(s):  
P53 Gene ◽  
Inhibitory Effect ◽  
Wild Type ◽  
Glioblastoma Cells ◽  
Content Type ◽  
Growth Inhibitory ◽  
Wild Type P53 ◽  
Fine Print ◽  
In Cells

Object. Clotrimazole, an antimycotic drug, inhibits proliferation of normal and cancer cells by downregulating the movement of intracellular Ca++ and K+. The authors examined the effect of clotrimazole on the growth and sensitivity to cisplatin of two human glioblastoma cell lines—A172, which has the wild-type p53 gene, and T98G, which has the mutant p53 gene in vitro.Methods. The A172 and T98G glioblastoma cells were exposed to clotrimazole and cell growth was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium chloride colorimetric assay. Clotrimazole produced a dose-dependent inhibition of cell proliferation and caused changes in cellular structure toward a well-differentiated form. The growth inhibitory effect of clotrimazole was reversible. Western immunoblot analysis revealed a marked increase in cellular glial fibrillary acidic protein and wild-type p53 and a decrease in c-myc and c-fos oncoproteins in both cell lines treated with clotrimazole. Flow cytometric analysis revealed that clotrimazole-treated cells accumulated in the G0/G1 phase with a marked decrease in cells in the S phase; when clotrimazole was washed out from the culture medium, cells again started to proliferate, with a marked decrease in cells in the G0/G1 phase and an increase in cells in the S phase. The growth inhibitory effect of clotrimazole could not be overcome by exogenous stimulation with either epidermal growth factor or c-myc peptide. A combined treatment with clotrimazole and cisplatin significantly enhanced cell cytotoxicity compared with treatment using either drug alone. A DNA fragmentation assay showed that both clotrimazole and cisplatin induced apoptosis, which was increased in cells treated by both drugs.Conclusions. The present study indicates that clotrimazole inhibits cell proliferation accompanied by morphological changes toward differentiation of glioblastoma cells and that this drug synergistically enhances the antitumor effect of cisplatin by inducing wild-type p53—mediated apoptosis.

Resistance of pleural mesothelioma cell lines to apoptosis: relation to expression of Bcl-2 and Bax

1998 ◽  
Vol 275 (1) ◽  
pp. L165-L171 ◽  
Author(s):  
Sudha Rani Narasimhan ◽  
Lin Yang ◽  
Brenda I. Gerwin ◽  
V. Courtney Broaddus
Keyword(s):  
Cell Lines ◽  
Calcium Ionophore ◽  
Mutant P53 ◽  
Pleural Mesothelioma ◽  
Wild Type ◽  
Altered Expression ◽  
Resistance To Therapy ◽  
Proapoptotic Protein ◽  
Mesothelioma Cell ◽  
Wild Type P53

A failure of normal apoptosis, often due to mutant p53, may contribute to the formation of a cancer and to its resistance to therapy. Mesothelioma, an asbestos-induced tumor, is highly resistant to therapy but generally expresses wild-type p53. We asked whether mesothelioma was resistant to apoptosis and whether resistance was associated with altered expression of the antiapoptotic protein Bcl-2 or proapoptotic protein Bax. We found that three mesothelioma cell lines (1 with wild-type p53) were highly resistant to apoptosis induced by oxidant stimuli (asbestos, H2O2) or nonoxidant stimuli (calcium ionophore) compared with primary cultured mesothelial cells. By immunostaining, one of these three lines expressed Bcl-2 but only during mitosis. By immunoblotting, 3 of 14 additional mesothelioma lines (9 of 14 with wild type p53) expressed Bcl-2 but all 14 of 14 expressed the proapoptotic Bax, giving a low ratio of Bcl-2 to Bax. We conclude that mesothelioma cell lines are resistant to apoptosis and that the failure in apoptosis is not explained by Bcl-2 but by other mechanisms that counteract the proapoptotic effect of Bax.

scholarly journals Circ_0003266 sponges miR-503-5p to suppress colorectal cancer progression via regulating PDCD4 expression

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Caihong Wen ◽  
Xiaoqing Feng ◽  
Honggang Yuan ◽  
Yong Gong ◽  
Guangsheng Wang
Keyword(s):  
Colorectal Cancer ◽  
Cell Proliferation ◽  
Cell Lines ◽  
Cancer Progression ◽  
Cell Counting ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Circular Rnas ◽  
Pdcd4 Expression ◽  
Novel Target

Abstract Background Circular RNAs (circRNAs) feature prominently in tumor progression. However, the biological function and molecular mechanism of circ_0003266 in colorectal cancer (CRC) require further investigation. Methods Circ_0003266 expression in 46 pairs CRC tissues / adjacent tissues, and CRC cell lines was detected by quantitative real-time polymerase chain reaction (qRT-PCR); after circ_0003266 was overexpressed or knocked down in CRC cells, cell proliferation, apoptosis, migration, and invasion were evaluated by the cell counting kit-8 (CCK-8), flow cytometry, and Transwell assays, respectively; the interaction among circ_0003266, miR-503-5p, and programmed cell death 4 (PDCD4) was confirmed using bioinformatics analysis and dual-luciferase reporter assay; PDCD4 protein expression in CRC cells was quantified using Western blot. Results Circ_0003266 was significantly lowly expressed in CRC tissues and cell lines. Circ_0003266 overexpression markedly repressed CRC cell proliferation, migration, and invasion, and accelerated the cell apoptosis, but its overexpression promoted the malignant phenotypes of CRC cells. PDCD4 was a direct target of miR-503-5p and circ_0003266 promoted PDCD4 expression by competitively sponging miR-503-5p. Conclusion Circ_0003266 suppresses the CRC progression via sponging miR-503-5p and regulating PDCD4 expressions, which suggests that circ_0003266 may serve as a novel target for the treatment of CRC.

scholarly journals The Anti-Tumor Activity of the NEDD8 Inhibitor Pevonedistat in Neuroblastoma

2021 ◽  
Vol 22 (12) ◽  
pp. 6565
Author(s):  
Jennifer H. Foster ◽  
Eveline Barbieri ◽  
Linna Zhang ◽  
Kathleen A. Scorsone ◽  
Myrthala Moreno-Smith ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Lines ◽  
Neuroblastoma Cell ◽  
Wild Type ◽  
Tumor Weight ◽  
Cycle Arrest ◽  
P53 Status ◽  
Neuroblastoma Cell Lines ◽  
Anti Tumor Activity

Pevonedistat is a neddylation inhibitor that blocks proteasomal degradation of cullin–RING ligase (CRL) proteins involved in the degradation of short-lived regulatory proteins, including those involved with cell-cycle regulation. We determined the sensitivity and mechanism of action of pevonedistat cytotoxicity in neuroblastoma. Pevonedistat cytotoxicity was assessed using cell viability assays and apoptosis. We examined mechanisms of action using flow cytometry, bromodeoxyuridine (BrDU) and immunoblots. Orthotopic mouse xenografts of human neuroblastoma were generated to assess in vivo anti-tumor activity. Neuroblastoma cell lines were very sensitive to pevonedistat (IC50 136–400 nM). The mechanism of pevonedistat cytotoxicity depended on p53 status. Neuroblastoma cells with mutant (p53MUT) or reduced levels of wild-type p53 (p53si-p53) underwent G2-M cell-cycle arrest with rereplication, whereas p53 wild-type (p53WT) cell lines underwent G0-G1 cell-cycle arrest and apoptosis. In orthotopic neuroblastoma models, pevonedistat decreased tumor weight independent of p53 status. Control mice had an average tumor weight of 1.6 mg + 0.8 mg versus 0.5 mg + 0.4 mg (p < 0.05) in mice treated with pevonedistat. The mechanism of action of pevonedistat in neuroblastoma cell lines in vitro appears p53 dependent. However, in vivo studies using mouse neuroblastoma orthotopic models showed a significant decrease in tumor weight following pevonedistat treatment independent of the p53 status. Novel chemotherapy agents, such as the NEDD8-activating enzyme (NAE) inhibitor pevonedistat, deserve further study in the treatment of neuroblastoma.

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