scholarly journals Fine-tuned repression of Drp1 driven mitochondrial fission primes a 'stem/progenitor-like state' to support neoplastic transformation

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Brian Spurlock ◽  
Danitra Parker ◽  
Malay Kumar Basu ◽  
Anita Hjelmeland ◽  
Sajina GC ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Model ◽  
Gene Knockout ◽  
Mitochondrial Fission ◽  
Neoplastic Transformation ◽  
Fine Tuning ◽  
Stem Cell Markers ◽  
Self Renewal ◽  
State Dependent ◽  
Slow Cycling

Gene knockout of the master regulator of mitochondrial fission, Drp1, prevents neoplastic transformation. Also, mitochondrial fission and its opposing process of mitochondrial fusion are emerging as crucial regulators of stemness. Intriguingly, stem/progenitor cells maintaining repressed mitochondrial fission are primed for self-renewal and proliferation. Using our newly derived carcinogen transformed human cell model we demonstrate that fine-tuned Drp1 repression primes a slow cycling 'stem/progenitor-like state', which is characterized by small networks of fused mitochondria and a gene-expression profile with elevated functional stem/progenitor markers (Krt15, Sox2 etc) and their regulators (Cyclin E). Fine tuning Drp1 protein by reducing its activating phosphorylation sustains the neoplastic stem cell markers. Whereas, fine-tuned reduction of Drp1 protein maintains the characteristic mitochondrial shape and gene-expression of the primed 'stem/progenitor-like state' to accelerate neoplastic transformation, and more complete reduction of Drp1 protein prevents it. Therefore, our data highlights a 'goldilocks'; level of Drp1 repression supporting stem/progenitor state dependent neoplastic transformation.

scholarly journals Fine-tuned repression of Drp1 driven mitochondrial fission primes a slow cycling stem/progenitor-like state towards accelerating neoplastic transformation of keratinocytes

2021 ◽  
Author(s):  
Kasturi Mitra ◽  
Brian M Spurlock ◽  
Danitra Parker ◽  
Malay Basu ◽  
Anita Hjelmeland ◽  
...  
Keyword(s):  
Progenitor Cell ◽  
Mitochondrial Fission ◽  
Neoplastic Transformation ◽  
Functional Markers ◽  
Causative Role ◽  
Self Renewal ◽  
Primed State ◽  
Carcinogen Exposure ◽  
Slow Cycling

The opposing processes of mitochondrial fission and fusion are emerging as crucial regulators of stem cells. Stem/progenitor cells maintaining repressed mitochondrial fission appear to be primed for self-renewal and proliferation. Here, we demonstrate the causative role of fine-tuned repression of Drp1, the master regulator of mitochondrial fission, in establishing a stem/progenitor-like state towards supporting carcinogen (TCDD) driven neoplastic transformation of keratinocytes. Fine-tuned Drp1 repression maintains small networks of fused mitochondria to sustain a unique gene-expression profile with elevated stem/progenitor cell functional markers (Krt15, Sox2 etc) and their regulators (Cyclin E). Cells with this mitochondria-primed state are slow cycling, susceptible to transformation, and when enriched by mild carcinogen exposure sustains elevated self-renewal/proliferation to form less differentiated tumors. More complete Drp1 repression sustains larger hyperfused mitochondria, represses lineage specific stem/progenitor genes and prevents transformation. Therefore, our data highlights a 'goldilocks' level of Drp1 repression that supports stem/progenitor cell dependent neoplastic transformation. Future studies would reveal if bodily stresses causing mild Drp1 repression could enrich this mitochondria-primed stem/progenitor like population in tissues making them vulnerable to neoplastic transformation.

scholarly journals Spontaneous malignant transformation of ovarian surface epithelial cells correlates with EMT alteration and stemness acquisition

2019 ◽  
Author(s):  
Bingyan Li ◽  
Hemei Zhang ◽  
Yi Guo ◽  
Lizhi Liu ◽  
Yongfeng Hou ◽  
...  
Keyword(s):  
Epithelial Mesenchymal Transition ◽  
Cell Model ◽  
Mrna Level ◽  
Neoplastic Transformation ◽  
Surface Epithelium ◽  
Ovarian Carcinomas ◽  
Self Renewal ◽  
Mesenchymal Transition ◽  
Ovarian Surface

Abstract Background In order to complete the physiological function of postovulatory repair during repeated ovulation, the ovarian surface epithelium (OSE) not only has to undergo epithelial-mesenchymal transition (EMT), but also possess the properties of somatic stem-like cells. However, there is no evidence to indicate that both EMT alteration and stemness acquisition are linked to epithelial ovarian carcinomas.Methods In this study, we established a cell model of spontaneous oncogenic transformation of mouse OSE (MOSE). The cell proliferation was assessed using clonogenic survival and soft agar. The self-renewal of cancer stem-like cells (CSCs) was determined by spheroid culture. CD44 + /CD117 + cells were analyzed using flow cytometer. The PCR array was used to determine the EMT-related mRNA level. Expression of pan-keratin, vimentin, E-cadherin, Snail1 and Slug were detected using western-blotting and immunofluorescences, respectively. The tumorigenesis were monitored by limiting dilution assay in vitro and in vivo .Results Based on morphological change, chromosomal number and proliferating ability, we defined three sequential stages of transformed cells as early, intermediate and late MOSE cells, respectively. We found that MOSE cells had dual characteristics of not only epithelial but mesenchymal nature as well. Over time, MOSE cells spontaneously developed characteristics of malignant cells and generated tumor nodules expressing both Pan-keratin and Vimentin. Furthermore, we found that the neoplastic transformation of MOSE was accompanied by continuous EMT-inducing signals including Snail1 and Slug. Concurrently, the increase of CD44 + /CD117 + cells and their self-renewal ability were associated with the progression of spontaneous neoplastic transformation of MOSE cells in vitro. Conclusion These results indicated that both EMT alteration and stemness acquisition were closely correlated with the spontaneous malignant progression of MOSE cells. Our findings provide new insights into the future to combat epithelial ovarian carcinomas.

Melanoma Stem Cells: The Dark Seed of Melanoma

2008 ◽  
Vol 26 (17) ◽  
pp. 2890-2894 ◽  
Author(s):  
Susan E. Zabierowski ◽  
Meenhard Herlyn
Keyword(s):  
Stem Cells ◽  
Side Population ◽  
Malignant Lesion ◽  
Therapeutic Strategies ◽  
Stem Cell Markers ◽  
Tumor Stem Cells ◽  
Side Population Cells ◽  
Self Renewal ◽  
Slow Cycling ◽  
Novel Therapeutic Strategies

Cells with stem-cell markers and features have recently been identified in melanoma tissues and cell lines. Melanoma stem-like cells possess many traits of tumor-initiating or tumor stem cells including self-renewal capacity, high tumorigenicity, and differentiation into various mesenchymal lineages, including melanocytic cells. Four subpopulations of melanoma-initiating cells have been distinguished: CD20+, CD133+, label-retaining or slow-cycling cells, and side-population cells with high efflux activities. Whether these are distinct or overlapping populations is currently under investigation. Ongoing studies are dissecting and characterizing the hierarchy of these subpopulations within a malignant lesion. Understanding these and the dynamics of clonal dominance will aid in the development of novel therapeutic strategies.

scholarly journals Spontaneous malignant transformation of ovarian surface epithelial cells correlates with EMT alteration and stemness acquisition

2019 ◽  
Author(s):  
Bingyan Li ◽  
Hemei Zhang ◽  
Yi Guo ◽  
Lizhi Liu ◽  
Yongfeng Hou ◽  
...  
Keyword(s):  
Epithelial Mesenchymal Transition ◽  
Cell Model ◽  
Mrna Level ◽  
Neoplastic Transformation ◽  
Surface Epithelium ◽  
Ovarian Carcinomas ◽  
Self Renewal ◽  
Mesenchymal Transition ◽  
Ovarian Surface

Abstract Background In order to complete the physiological function of postovulatory repair during repeated ovulation, the ovarian surface epithelium (OSE) not only has to undergo epithelial-mesenchymal transition (EMT), but also possess the properties of somatic stem-like cells. However, there is no evidence to indicate that both EMT alteration and stemness acquisition are linked to epithelial ovarian carcinomas.Methods In this study, we established a cell model of spontaneous oncogenic transformation of mouse OSE (MOSE). The cell proliferation was assessed using clonogenic survival and soft agar. The self-renewal of cancer stem-like cells (CSCs) was determined by spheroid culture. CD44 + /CD117 + cells were analyzed using flow cytometer. The PCR array was used to determine the EMT-related mRNA level. Expression of pan-keratin, vimentin, E-cadherin, Snail1 and Slug were detected using western-blotting and immunofluorescences, respectively. The tumorigenesis were monitored by limiting dilution assay in vitro and in vivo .Results Based on morphological change, chromosomal number and proliferating ability, we defined three sequential stages of transformed cells as early, intermediate and late MOSE cells, respectively. We found that MOSE cells had dual characteristics of not only epithelial but mesenchymal nature as well. Over time, MOSE cells spontaneously developed characteristics of malignant cells and generated tumor nodules expressing both Pan-keratin and Vimentin. Furthermore, we found that the neoplastic transformation of MOSE was accompanied by continuous EMT-inducing signals including Snail1 and Slug. Concurrently, the increase of CD44 + /CD117 + cells and their self-renewal ability were associated with the progression of spontaneous neoplastic transformation of MOSE cells in vitro. Conclusion These results indicated that both EMT alteration and stemness acquisition were closely correlated with the spontaneous malignant progression of MOSE cells. Our findings provide new insights into the future to combat epithelial ovarian carcinomas.

Characterization of cancer stem-like cells in chordoma

2012 ◽  
Vol 116 (4) ◽  
pp. 810-820 ◽  
Author(s):  
Esra Aydemir ◽  
Omer Faruk Bayrak ◽  
Fikrettin Sahin ◽  
Basar Atalay ◽  
Gamze Torun Kose ◽  
...  
Keyword(s):  
Gene Expression ◽  
Retinoic Acid ◽  
Osteogenic Differentiation ◽  
Soft Agar ◽  
Cell Detection ◽  
Stem Cell Markers ◽  
Osteogenic Differentiation Medium ◽  
Self Renewal ◽  
Cell Markers ◽  
New Approaches

Object Chordomas are locally aggressive bone tumors known to arise from the remnants of the notochord. Because chordomas are rare, molecular studies aimed at developing new therapies are scarce and new approaches are needed. Chordoma cells and cancer stem-like cells share similar characteristics, including self-renewal, differentiation, and resistance to chemotherapy. Therefore, it seems possible that chordomas might contain a subpopulation of cancer stem-like cells. The aim of this study is to determine whether cancer stem-like cells might be present in chordomas. Methods In this study, the authors used gene expression analysis for common cancer stem-like cellmarkers, including c-myc, SSEA-1, oct4, klf4, sox2, nanog, and brachyury, and compared chordoma cells and tissues with nucleus pulposus tissues (disc degenerated nontumorigenic tissues). Differentiation through agents such as all-trans retinoic acid and osteogenic differentiation medium was induced to the chordoma cells. Additionally, U-CH1 cells were sorted via magnetic cell sorting for stem cell markers CD133 and CD15. After separation, positive and negative cells for these markers were grown in a nonadherent environment, soft agar, to determine whether the presence of these cancer stem-like cells might be responsible for initiating chordoma. The results were compared with those of untreated cells in terms of migration, proliferation, and gene expression by using reverse transcriptase polymerase chain reaction. Results The results indicate that chordoma cells might be differentiating and committing into an osteogenic lineage when induced with the osteogenic differentiation agent. Chordoma cells that are induced with retinoic acid showed slower migration and proliferation rates when compared with the untreated cells. Chordoma cells that were found to be enriched by cancer stem-like cell markers, namely CD133 and CD15, were able to live in a nonadherent soft agar medium, demonstrating a self-renewal capability. To the authors' knowledge, this is the first time that cancer stem-like cell markers were also found to be expressed in chordoma cells and tissues. Conclusions Cancer stem-like cell detection might be an important step in determining the recurrent and metastatic characteristics of chordoma. This finding may lead to the development of new approaches toward treatments of chordomas.

scholarly journals CRISPR-assisted multi-dimensional regulation for fine-tuning gene expression in Bacillus subtilis

2019 ◽  
Vol 47 (7) ◽  
pp. e40-e40 ◽  
Author(s):  
Zhenghui Lu ◽  
Shihui Yang ◽  
Xin Yuan ◽  
Yunyun Shi ◽  
Li Ouyang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bacillus Subtilis ◽  
Fine Tuning

scholarly journals Establishment of a novel hepatic steatosis cell model by Cas9/sgRNA-mediated DGKθ gene knockout

2017 ◽  
Author(s):  
Jingjing Zhang ◽  
Junli Zhao ◽  
Xiaojing Zheng ◽  
Kai Cai ◽  
Qinwen Mao ◽  
...  
Keyword(s):  
Hepatic Steatosis ◽  
Cell Model ◽  
Gene Knockout

scholarly journals Competing Endogenous RNAs in Cervical Carcinogenesis: A New Layer of Complexity

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 991
Author(s):  
Fernanda Costa Brandão Berti ◽  
Sara Cristina Lobo-Alves ◽  
Camila de Freitas Oliveira-Toré ◽  
Amanda Salviano-Silva ◽  
Karen Brajão de Oliveira ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fine Tuning ◽  
Molecular Networks ◽  
Cervical Carcinogenesis ◽  
Molecular Changes ◽  
Cellular Processes ◽  
Target Mrnas ◽  
Competing Endogenous Rnas ◽  
Cervical Cells ◽  
Post Transcriptional Regulation

MicroRNAs (miRNAs) regulate gene expression by binding to complementary sequences within target mRNAs. Apart from working ‘solo’, miRNAs may interact in important molecular networks such as competing endogenous RNA (ceRNA) axes. By competing for a limited pool of miRNAs, transcripts such as long noncoding RNAs (lncRNAs) and mRNAs can regulate each other, fine-tuning gene expression. Several ceRNA networks led by different lncRNAs—described here as lncRNA-mediated ceRNAs—seem to play essential roles in cervical cancer (CC). By conducting an extensive search, we summarized networks involved in CC, highlighting the major impacts of such dynamic molecular changes over multiple cellular processes. Through the sponging of distinct miRNAs, some lncRNAs as HOTAIR, MALAT1, NEAT1, OIP5-AS1, and XIST trigger crucial molecular changes, ultimately increasing cell proliferation, migration, invasion, and inhibiting apoptosis. Likewise, several lncRNAs seem to be a sponge for important tumor-suppressive miRNAs (as miR-140-5p, miR-143-3p, miR-148a-3p, and miR-206), impairing such molecules from exerting a negative post-transcriptional regulation over target mRNAs. Curiously, some of the involved mRNAs code for important proteins such as PTEN, ROCK1, and MAPK1, known to modulate cell growth, proliferation, apoptosis, and adhesion in CC. Overall, we highlight important lncRNA-mediated functional interactions occurring in cervical cells and their closely related impact on cervical carcinogenesis.

scholarly journals Interaction of 7SK with the Smn complex modulates snRNP production

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Changhe Ji ◽  
Jakob Bader ◽  
Pradhipa Ramanathan ◽  
Luisa Hennlein ◽  
Felix Meissner ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcriptional Regulation ◽  
Fine Tuning ◽  
Global Changes ◽  
Functional Association ◽  
Transcriptional Inhibition ◽  
Smn Complex ◽  
Core Components

AbstractGene expression requires tight coordination of the molecular machineries that mediate transcription and splicing. While the interplay between transcription kinetics and spliceosome fidelity has been investigated before, less is known about mechanisms regulating the assembly of the spliceosomal machinery in response to transcription changes. Here, we report an association of the Smn complex, which mediates spliceosomal snRNP biogenesis, with the 7SK complex involved in transcriptional regulation. We found that Smn interacts with the 7SK core components Larp7 and Mepce and specifically associates with 7SK subcomplexes containing hnRNP R. The association between Smn and 7SK complexes is enhanced upon transcriptional inhibition leading to reduced production of snRNPs. Taken together, our findings reveal a functional association of Smn and 7SK complexes that is governed by global changes in transcription. Thus, in addition to its canonical nuclear role in transcriptional regulation, 7SK has cytosolic functions in fine-tuning spliceosome production according to transcriptional demand.

scholarly journals Refactoring of a synthetic raspberry ketone pathway with EcoFlex

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Simon J. Moore ◽  
Yonek B. Hleba ◽  
Sarah Bischoff ◽  
David Bell ◽  
Karen M. Polizzi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Synthetic Biology ◽  
Combinatorial Libraries ◽  
Value Added ◽  
Microtiter Plate ◽  
Fine Tuning ◽  
Golden Gate ◽  
E Coli ◽  
Fine Chemical ◽  
Raspberry Ketone

Abstract Background  A key focus of synthetic biology is to develop microbial or cell-free based biobased routes to value-added chemicals such as fragrances. Originally, we developed the EcoFlex system, a Golden Gate toolkit, to study genes/pathways flexibly using Escherichia coli heterologous expression. In this current work, we sought to use EcoFlex to optimise a synthetic raspberry ketone biosynthetic pathway. Raspberry ketone is a high-value (~ £20,000 kg−1) fine chemical farmed from raspberry (Rubeus rubrum) fruit. Results  By applying a synthetic biology led design-build-test-learn cycle approach, we refactor the raspberry ketone pathway from a low level of productivity (0.2 mg/L), to achieve a 65-fold (12.9 mg/L) improvement in production. We perform this optimisation at the prototype level (using microtiter plate cultures) with E. coli DH10β, as a routine cloning host. The use of E. coli DH10β facilitates the Golden Gate cloning process for the screening of combinatorial libraries. In addition, we also newly establish a novel colour-based phenotypic screen to identify productive clones quickly from solid/liquid culture. Conclusions  Our findings provide a stable raspberry ketone pathway that relies upon a natural feedstock (L-tyrosine) and uses only constitutive promoters to control gene expression. In conclusion we demonstrate the capability of EcoFlex for fine-tuning a model fine chemical pathway and provide a range of newly characterised promoter tools gene expression in E. coli.

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