scholarly journals Silencing of SRRM4 suppresses microexon inclusion and promotes tumor growth across cancers

PLoS Biology ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. e3001138
Author(s):  
Sarah A. Head ◽  
Xavier Hernandez-Alias ◽  
Jae-Seong Yang ◽  
Ludovica Ciampi ◽  
Violeta Beltran-Sastre ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Rna Splicing ◽  
Xenograft Model ◽  
Selective Advantage ◽  
Altered Expression ◽  
Mouse Xenograft Model ◽  
Evolutionarily Conserved ◽  
Tumor Types ◽  
Splicing Patterns

RNA splicing is widely dysregulated in cancer, frequently due to altered expression or activity of splicing factors (SFs). Microexons are extremely small exons (3–27 nucleotides long) that are highly evolutionarily conserved and play critical roles in promoting neuronal differentiation and development. Inclusion of microexons in mRNA transcripts is mediated by the SF Serine/Arginine Repetitive Matrix 4 (SRRM4), whose expression is largely restricted to neural tissues. However, microexons have been largely overlooked in prior analyses of splicing in cancer, as their small size necessitates specialized computational approaches for their detection. Here, we demonstrate that despite having low expression in normal nonneural tissues, SRRM4 is further silenced in tumors, resulting in the suppression of normal microexon inclusion. Remarkably, SRRM4 is the most consistently silenced SF across all tumor types analyzed, implying a general advantage of microexon down-regulation in cancer independent of its tissue of origin. We show that this silencing is favorable for tumor growth, as decreased SRRM4 expression in tumors is correlated with an increase in mitotic gene expression, and up-regulation of SRRM4 in cancer cell lines dose-dependently inhibits proliferation in vitro and in a mouse xenograft model. Further, this proliferation inhibition is accompanied by induction of neural-like expression and splicing patterns in cancer cells, suggesting that SRRM4 expression shifts the cell state away from proliferation and toward differentiation. We therefore conclude that SRRM4 acts as a proliferation brake, and tumors gain a selective advantage by cutting off this brake.

scholarly journals MNAT1 promotes proliferation and the chemo-resistance of osteosarcoma cell to cisplatin through regulating PI3K/Akt/mTOR pathway

BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Chensheng Qiu ◽  
Weiliang Su ◽  
Nana Shen ◽  
Xiaoying Qi ◽  
Xiaolin Wu ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Xenograft Model ◽  
Mtor Pathway ◽  
Regulation Mechanism ◽  
Osteosarcoma Cell ◽  
Migration Ability ◽  
Mouse Xenograft Model

Abstract Background MNAT1 (menage a trois 1, MAT1), a cyclin-dependent kinase-activating kinase (CAK) complex, highly expressed in diverse cancers and was involved in cancer molecular pathogenesis. However, its deliverance profile and biological function in osteosarcoma (OS) remain unclear. Methods The expression of MNAT1 in OS was detected by western blot (WB) and immunohistochemistry (IHC). The potential relationship between MNAT1 molecular level expression and OS clinical expectations were analyzed according to tissues microarray (TMA). Proliferation potential of OS cells was evaluated in vitro based on CCK8 and OS cells colony formation assays, while OS cells transwell and in situ tissue source wound healing assays were employed to analyze the OS cells invasion and migration ability in vitro. A nude mouse xenograft model was used to detect tumor growth in vivo. In addition, ordinary bioinformatics analysis and experimental correlation verification were performed to investigate the underlying regulation mechanism of OS by MNAT1. Results In this research, we found and confirmed that MNAT1 was markedly over-expressed in OS tissue derived in situ, also, highly MNAT1 expression was closely associated with bad clinical expectations. Functional studies had shown that MNAT1 silencing could weaken the invasion, migration and proliferation of OS cells in vitro, and inhibit OS tumor growth in vivo. Mechanism study indicated that MNAT1 contributed to the progression of OS via the PI3K/Akt/mTOR pathway. We further verified that the MNAT1 was required in the regulation of OS chemo-sensitivity to cisplatin (DDP). Conclusions Taken together, the data of the present study demonstrate a novel molecular mechanism of MNAT1 involved in the formation of DDP resistance of OS cells.

Effect of mebendazole on melanoma xenograft growth through targeting of bcl-2

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 9075-9075
Author(s):  
N. A. Doudican ◽  
R. Pennell ◽  
T. Tu ◽  
L. Liebes ◽  
A. Pavlick ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Xenograft Model ◽  
Melanoma Cells ◽  
High Dose ◽  
Tumor Diameter ◽  
Proliferating Cells ◽  
Melanoma Tumor ◽  
Mouse Xenograft Model ◽  
Melanoma Growth

9075 Background: Defects in apoptosis are thought to contribute to melanoma chemoresistance, making the anti-apoptotic protein Bcl-2 an attractive therapeutic target. We identified mebendazole (MBZ), a microtubule binding agent, as an inducer of melanoma cytotoxicity via a Bcl-2 dependent mechanism in vitro (Mol Cancer Res, Aug 2008). In the present study, we assessed the effect of MBZ on human melanoma tumor growth and progression in a mouse xenograft model and compared the ability of MBZ to inhibit growth of cultured melanoma cells to that of oblimersen (OBL), an antisense drug targeting Bcl-2. Methods: Growth of human M-14 melanoma xenografts in mice administered MBZ orally at doses from 0.1 to 2 mg were compared to tumor growth in mice receiving 100mg/kg intraperitoneal temozolomide (TMZ) or vehicle alone. Tumor diameter, volume, histopathology, and immunohistochemical staining of caspase 3 and Ki67 were assessed. Bcl-2 phosphorylation was determined by immunoblotting. MBZ and OBL-induced melanoma growth inhibition was analyzed by MTT assay. Results: Anti-melanoma effects of MBZ were dose- dependent up to 1 mg which displayed a 72% reduction in tumor volume compared to vehicle treated mice. This reduction in volume was accompanied by a 46% decrease in proliferating cells and an 81% increase in apoptotic cells. Moreover, 1 mg MBZ inhibited tumor growth as effectively as high dose TMZ, the current melanoma standard of care. Orally administered MBZ treatment resulted in Bcl-2 phosphorylation in vivo, further confirming its mechanism of action. MBZ inhibited growth of melanoma cells in culture more effectively than OBL with GI50 values of 0.32 uM and 7.45 uM, respectively. Conclusions: MBZ safely and effectively inhibits melanoma growth and progression in a xenograft model. A phase II clinical trial investigating MBZ's utility as adjuvant therapy in patients with stage IV, resected melanoma is planned. No significant financial relationships to disclose.

scholarly journals Distinct inhibitory efficiency of siRNAs and DNAzymes to β1 integrin subunit in blocking tumor growth.

2013 ◽  
Vol 60 (1) ◽  
Author(s):  
Magdalena Wiktorska ◽  
Izabela Sacewicz-Hofman ◽  
Olga Stasikowska-Kanicka ◽  
Marian Danilewicz ◽  
Jolanta Niewiarowska
Keyword(s):  
Tumor Growth ◽  
Xenograft Model ◽  
Tumor Formation ◽  
Integrin Subunit ◽  
Β1 Integrin ◽  
Mouse Xenograft ◽  
Mouse Xenograft Model ◽  
Intracellular Compartments

Receptors of the β1 integrin family are involved in many tumor-promoting activities. There are several approaches currently used to control integrin activity, and thus to potentially restrain tumor metastasis and angiogenesis. In this study, we compared inhibitory efficiencies of siRNA and DNAzymes against the β1 integrin subunit (DEβ1), in a mouse xenograft model. Both inhibitors were used under their most favorable conditions, in terms of concentrations, incubation time and lack of cytotoxic effects. Transfection of siRNAβ1 or DEβ1 remarkably inhibited the growth of both PC3 and HT29 colon cancer cells in vitro, and decreased their capability of initiating tumor formation in the mouse xenograft model. siRNAβ1 appeared to be slightly more efficient than DEβ1 when tested in vitro, however it was comparably less proficient in blocking the tumor growth in vivo. We conclude the DNAzyme, due to its greater resistance to degradation in extra- and intracellular compartments, to be a superior inhibitor of tumor growth in long lasting experiments in vivo when compared to siRNA, while the latter seems to be more efficient in blocking β1 expression during in vitro experiments using cell cultures.

scholarly journals Overexpression of Long Non-Coding RNA NNT-AS1 Correlates with Tumor Progression and Poor Prognosis in Osteosarcoma

2018 ◽  
Vol 45 (5) ◽  
pp. 1904-1914 ◽  
Author(s):  
Hui Ye ◽  
Jinkuang Lin ◽  
Xuedong Yao ◽  
Yizhong Li ◽  
Xiaobin Lin ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Poor Prognosis ◽  
Significant Risk ◽  
Xenograft Model ◽  
Significant Risk Factor ◽  
Tumor Xenograft ◽  
Migration And Invasion ◽  
Mouse Xenograft Model

Background/Aims: Increasing evidence demonstrates that long non-coding RNAs (lncRNAs) play critical regulatory roles in cancers, including osteosarcoma. A previous study showed that Nicotinamide Nucleotide Transhydrogenase-antisense RNA1 (NNT-AS1) was aberrantly expressed in several types of cancer. However, the potential biological roles and regulatory mechanisms of NNT-AS1 in osteosarcoma progression remain unknown. Methods: Quantitative RT-PCR was performed to examine the expression of NNT-AS1 in human tissues and cells. The biological functions of NNT-AS1 were determined by CCK-8, colony formation, Flow cytometry and Transwell assays in vitro. A mouse xenograft model was performed to investigate the effect of NNT-AS1 on tumor growth in vivo. Results: In this study, we found the expression of NNT-AS1 was significantly increased in tumor tissues compared to adjacent normal tissues. Furthermore, upregulated NNT-AS1 expression predicted poor prognosis and was an independent and significant risk factor for osteosarcoma patient survival. Further experiments revealed that NNT-AS1 knockdown significantly inhibited cell proliferation by inducing cell cycle arrest and promoting apoptosis in osteosarcoma cells. Moreover, NNT-AS1 silencing suppressed cell migration and invasion in vitro. In a tumor xenograft model, knockdown of NNT-AS1 suppressed tumor growth of OS-732 cells in vivo. Conclusions: Taken together, these findings indicate that NNT-AS1 functions as an oncogene in osteosarcoma and could be a novel diagnostic and therapeutic target for osteosarcoma.

scholarly journals Hypoxia-regulated expression of CD44 and osteopontin can change the phenotype of glioma stem-like cells from highly invasive to less invasive/proliferative tumors in glioblastoma

2020 ◽  
Author(s):  
Masahiro Nishikawa ◽  
Akihiro Inoue ◽  
Takanori Ohnishi ◽  
Hajime Yano ◽  
Saya Ozaki ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Xenograft Model ◽  
Migration And Invasion ◽  
Invasive Phenotype ◽  
Moderate Hypoxia ◽  
Less Invasive ◽  
Mouse Xenograft Model ◽  
Phenotypic Transition

Abstract Background The poor prognosis of glioblastoma multiforme (GBM) is primarily due to highly invasive and highly migratory glioma stem-like cells (GSCs) in tumors. Upon GBM recurrence or progression, the highly invasive phenotype of GSCs changes to a less-motile, proliferative phenotype, thus generating tumor mass. Elucidating the molecular mechanism underlying this phenotypic transition could lead to the identification of effective molecular targets for treating GBM. Methods We examined mRNA expression of hypoxia-inducible factor (HIF)-1α, HIF-2α, CD44, and osteopontin in GBM tissues and investigated the effect of hypoxia (1% O2: severe or 5% O2: moderate) on expression of these molecules using two lines of cultured GSCs. We also analyzed the effect of osteopontin on the invasiveness, migration, and proliferation of GSCs under hypoxic conditions. In addition, the effect of CD44 knockdown on tumor growth and survival were investigated in vitro and in vivo using a mouse xenograft model. Results Severe hypoxia upregulates CD44 expression via activation of HIF-1α, inducing GSCs to assume a highly invasive phenotype. In contrast, moderate hypoxia upregulates osteopontin expression via activation of HIF-2α. Osteopontin in turn binds to CD44, simultaneously inhibiting CD44-promoted GSC migration and invasion and stimulating GSC proliferation, resulting in GSCs assuming a less-invasive, highly proliferative phenotype. CD44 knockdown significantly inhibited GSC migration and invasion both in vitro and in vivo. However, although CD44 knockdown did not affect tumor growth in vitro, mouse brain tumors generated from GSCs with CD44 knockdown exhibited diminished invasiveness, and the mice survived significantly longer than control mice. In contrast, siRNA-mediated silencing of the osteopontin gene led to decreased GSC proliferation, but the osteopontin-mediated inhibition of high GSC migratory behavior and invasiveness was diminished. Conclusion The highly invasive phenotype of GSCs can be reversed by switching from severe to moderate hypoxia, leading to less-invasive and proliferative tumors. CD44 and osteopontin, which are expressed in a mutually exclusive manner under severe or moderate hypoxia, play a central role in regulating GSC invasion and proliferation by inducing a phenotypic transition, suggesting that these molecules could be effective targets for treating both primary and recurrent GBM.

scholarly journals Molecular characterization of chordoma xenografts generated from a novel primary chordoma cell source and two chordoma cell lines

2014 ◽  
Vol 21 (3) ◽  
pp. 386-393 ◽  
Author(s):  
Isaac O. Karikari ◽  
Christopher L. Gilchrist ◽  
Liufang Jing ◽  
David A. Alcorta ◽  
Jun Chen ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Cell Lines ◽  
Expression Profiles ◽  
Xenograft Model ◽  
Cell Types ◽  
Molecular Characteristics ◽  
Intense Staining ◽  
Mouse Xenograft Model ◽  
Cell Source

Object Chordoma cells can generate solid-like tumors in xenograft models that express some molecular characteristics of the parent tumor, including positivity for brachyury and cytokeratins. However, there is a dearth of molecular markers that relate to chordoma tumor growth, as well as the cell lines needed to advance treatment. The objective in this study was to isolate a novel primary chordoma cell source and analyze the characteristics of tumor growth in a mouse xenograft model for comparison with the established U-CH1 and U-CH2b cell lines. Methods Primary cells from a sacral chordoma, called “DVC-4,” were cultured alongside U-CH1 and U-CH2b cells for more than 20 passages and characterized for expression of CD24 and brachyury. While brachyury is believed essential for driving tumor formation, CD24 is associated with healthy nucleus pulposus cells. Each cell type was subcutaneously implanted in NOD/SCID/IL2Rγnull mice. The percentage of solid tumors formed, time to maximum tumor size, and immunostaining scores for CD24 and brachyury (intensity scores of 0–3, heterogeneity scores of 0–1) were reported and evaluated to test differences across groups. Results The DVC-4 cells retained chordoma-like morphology in culture and exhibited CD24 and brachyury expression profiles in vitro that were similar to those for U-CH1 and U-CH2b. Both U-CH1 and DVC-4 cells grew tumors at rates that were faster than those for U-CH2b cells. Gross tumor developed at nearly every site (95%) injected with U-CH1 and at most sites (75%) injected with DVC-4. In contrast, U-CH2b cells produced grossly visible tumors in less than 50% of injected sites. Brachyury staining was similar among tumors derived from all 3 cell types and was intensely positive (scores of 2–3) in a majority of tissue sections. In contrast, differences in the pattern and intensity of staining for CD24 were noted among the 3 types of cell-derived tumors (p < 0.05, chi-square test), with evidence of intense and uniform staining in a majority of U-CH1 tumor sections (score of 3) and more than half of the DVC-4 tumor sections (scores of 2–3). In contrast, a majority of sections from U-CH2b cells stained modestly for CD24 (scores of 1–2) with a predominantly heterogeneous staining pattern. Conclusions This is the first report on xenografts generated from U-CH2b cells in which a low tumorigenicity was discovered despite evidence of chordoma-like characteristics in vitro. For tumors derived from a primary chordoma cell and U-CH1 cell line, similarly intense staining for CD24 was observed, which may correspond to their similar potential to grow tumors. In contrast, U-CH2b tumors stained less intensely for CD24. These results emphasize that many markers, including CD24, may be useful in distinguishing among chordoma cell types and their tumorigenicity in vivo.

scholarly journals Anticancer effects of the combined Thai noni juice ethanolic extracts and 5-fluorouracil against cholangiocarcinoma cells in vitro and in vivo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeerati Prompipak ◽  
Thanaset Senawong ◽  
Banchob Sripa ◽  
Albert J. Ketterman ◽  
Suppawit Utaiwat ◽  
...  
Keyword(s):  
Nude Mice ◽  
Combination Treatment ◽  
Synergistic Effects ◽  
Single Agent ◽  
Xenograft Model ◽  
Ethanolic Extract ◽  
Model Combination ◽  
Mouse Xenograft Model ◽  
Ethanolic Extracts

AbstractApplication of 5-fluorouracil (5-FU) in cholangiocarcinoma (CCA) is limited by adverse side effects and chemoresistance. Therefore, the combination therapy of 5-FU with other substances, especially natural products may provide a new strategy for CCA treatment. The aim of this study was to evaluate the combination effects of 5-FU and two ethanolic extracts of Thai noni juice (TNJ) products on CCA cell lines and nude mice xenografts. The results of antiproliferative assay showed the combination treatment of 5-FU and each TNJ ethanolic extract exerted more cytotoxicity on CCA cells than either single agent treatment. Synergistic effects of drug combinations can enable the dose reduction of 5-FU. The mechanism underlying a combination treatment was apoptosis induction through an activation of p53 and Bax proteins. In the nude mouse xenograft model, combination treatments of 5-FU with each TNJ ethanolic extract suppressed the growth of CCA cells implanted mice more than single agent treatments with no effects on mouse body weight, kidney, and spleen. Moreover, low doses of TNJ ethanolic extracts reduced the hepatotoxicity of 5-FU in nude mice. Taken together, these data suggested that the ethanolic extracts of TNJ products can enhance the anti-CCA effect and reduce toxicity of 5-FU.

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