scholarly journals A different approach to tumour suppression. The Alexandra Kefalides Memorial Lecture

1996 ◽  
Vol 109 (9) ◽  
pp. 2189-2197 ◽  
Author(s):  
H. Harris ◽  
J. Rawlins ◽  
J. Sharps
Keyword(s):  
Hybrid Cell ◽  
Terminal Differentiation ◽  
Therapeutic Benefit ◽  
Memorial Lecture ◽  
Parent Cell ◽  
Malignant Cells ◽  
Clinical Context ◽  
Tumour Suppression ◽  
Keratin 1

When tumour cells are fused with normal ones, malignancy is suppressed. It has been shown that this suppression is associated with the imposition on the hybrid cell of the terminal differentiation programme of the normal parent cell. We report here the consequences of imposing the synthesis of keratin 1 and keratin 10, markers of terminal differentiation in the epidermal keratinocyte, on malignant cells of keratinocyte and non-keratinocyte lineage. We find that there is extreme selection in vivo against cells making keratin 1: tumours arising from inocula of such cells are invariably produced by the selective overgrowth of cells in which keratin 1 synthesis has been drastically reduced, usually to trace levels. No such selection operates against keratin 10. It is possible that if substantial synthesis of keratin 1 could be induced in malignant cells in a clinical context, some therapeutic benefit might accrue.

scholarly journals Suppression of malignancy in hybrid cells: the mechanism

1985 ◽  
Vol 79 (1) ◽  
pp. 83-94 ◽  
Author(s):  
H. Harris
Keyword(s):  
Extracellular Matrix ◽  
Terminal Differentiation ◽  
Parent Cell ◽  
Malignant Cells ◽  
Hybrid Cells ◽  
Malignant Phenotype ◽  
Diploid Parent ◽  
Wide Range ◽  
Secondary Consequence

When malignant cells, defined by their ability to grow progressively in genetically compatible hosts, are fused with diploid fibroblasts of the same species, the resulting hybrid cells, so long as they retain certain specific chromosomes donated by the diploid parent cell, are non-malignant. When these particular chromosomes are eliminated from the hybrid, the malignant phenotype reappears, and the segregant cell is again able to grow progressively in vivo. In the present experiments the histological character of the lesions produced by the inoculation of crosses between malignant and non-malignant cells was examined. It was found, in a wide range of material, and without exception, that where one or other of the parent cells in the cross was of fibroblastic lineage, malignancy was suppressed when the hybrid cells produced a collagenous extracellular matrix in vivo; and it reappeared when genetic segregants were produced that had lost the ability to produce this matrix. These results are interpreted in terms of a general model in which it is proposed that the progressive multiplication of malignant cells in vivo is a secondary consequence of a genetically stable impairment of terminal differentiation.

scholarly journals Platelet-Released Growth Factors Induce Differentiation of Primary Keratinocytes

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Andreas Bayer ◽  
Mersedeh Tohidnezhad ◽  
Justus Lammel ◽  
Sebastian Lippross ◽  
Peter Behrendt ◽  
...  
Keyword(s):  
Gene Expression ◽  
Growth Factors ◽  
Terminal Differentiation ◽  
Human Keratinocytes ◽  
Keratinocyte Differentiation ◽  
Dependent Manner ◽  
Primary Human Keratinocytes ◽  
Transglutaminase 1 ◽  
Keratin 1

Autologous thrombocyte concentrate lysates, for example, platelet-released growth factors, (PRGFs) or their clinically related formulations (e.g., Vivostat PRF®) came recently into the physicians’ focus as they revealed promising effects in regenerative and reparative medicine such as the support of healing of chronic wounds. To elucidate the underlying mechanisms, we analyzed the influence of PRGF and Vivostat PRF on human keratinocyte differentiation in vitro and on epidermal differentiation status of skin wounds in vivo. Therefore, we investigated the expression of early (keratin 1 and keratin 10) and late (transglutaminase-1 and involucrin) differentiation markers. PRGF treatment of primary human keratinocytes decreased keratin 1 and keratin 10 gene expression but induced involucrin and transglutaminase-1 gene expression in an epidermal growth factor receptor- (EGFR-) dependent manner. In concordance with these results, microscopic analyses revealed that PRGF-treated human keratinocytes displayed morphological features typical of keratinocytes undergoing terminal differentiation. In vivo treatment of artificial human wounds with Vivostat PRF revealed a significant induction of involucrin and transglutaminase-1 gene expression. Together, our results indicate that PRGF and Vivostat PRF induce terminal differentiation of primary human keratinocytes. This potential mechanism may contribute to the observed beneficial effects in the treatment of hard-to-heal wounds with autologous thrombocyte concentrate lysates in vivo.

scholarly journals Pevonedistat targets malignant cells in myeloproliferative neoplasms in vitro and in vivo via NFkB pathway inhibition

2021 ◽  
Author(s):  
Tim Kong ◽  
Angelo Brunelli Albertoni Laranjeira ◽  
Taylor Collins ◽  
Elisa S. De Togni ◽  
Abigail J. Wong ◽  
...  
Keyword(s):  
Mouse Models ◽  
Myeloproliferative Neoplasms ◽  
Symptomatic Relief ◽  
Myeloproliferative Neoplasm ◽  
Colony Growth ◽  
Therapeutic Benefit ◽  
Malignant Cells ◽  
Pathway Inhibition

Targeted inhibitors of JAK2 (e.g. ruxolitinib) often provide symptomatic relief for myeloproliferative neoplasm (MPN) patients, but the malignant clone persists and remains susceptible to disease transformation. These observations suggest that targeting alternative dysregulated signaling pathways may provide therapeutic benefit. Previous studies identified NFϰB pathway hyperactivation in myelofibrosis (MF) and secondary acute myeloid leukemia (sAML) that was insensitive to JAK2 inhibition. Here, we provide evidence that NFϰB pathway inhibition via pevonedistat targets malignant cells in MPN patient samples as well as in MPN and patient-derived xenograft mouse models that is non-redundant with ruxolitinib. Colony forming assays revealed preferential inhibition of MF colony growth compared to normal colony formation. In mass cytometry studies, pevonedistat blunted canonical TNFα responses in MF and sAML patient CD34+ cells. Pevonedistat also inhibited hyperproduction of inflammatory cytokines more effectively than ruxolitinib. Upon pevonedistat treatment alone or in combination with ruxolitinib, MPN mouse models exhibited reduced disease burden and improved survival. These studies demonstrating efficacy of pevonedistat in MPN cells in vitro as well as in vivo provide a rationale for therapeutic inhibition of NFϰB signaling for MF treatment. Based on these findings, a Phase I clinical trial combining pevonedistat with ruxolitinib has been initiated.

Total inhibition of involucrin synthesis by a novel two-step antisense procedure. Further examination of the relationship between differentiation and malignancy in hybrid cells

1992 ◽  
Vol 102 (4) ◽  
pp. 799-805 ◽  
Author(s):  
E.F. Griffin ◽  
H. Harris
Keyword(s):  
Cell Line ◽  
Target Genes ◽  
Hybrid Cell ◽  
Terminal Differentiation ◽  
Complete Inactivation ◽  
Total Inhibition ◽  
Antisense Constructs ◽  
Progressive Growth ◽  
Normal Human

A novel procedure involving the sequential use of two different antisense constructs has been used to inhibit the synthesis of involucrin in a hybrid cell line formed by the fusion of a human cervical carcinoma cell with a normal human keratinocyte (ESH100P6). In this cell line, and other similar hybrids, malignancy, as measured by progressive growth in vivo, is suppressed; and it has been shown that the keratinocyte imposes its own programme of terminal differentiation on the non-malignant hybrid cell. In particular, involucrin, a precursor of one of the major components of the cornified envelope of mature keratinocytes, continues to be produced. When, however, malignant segregants arise in the hybrid cell population, the terminal differentiation programme of the keratinocyte is not expressed and involucrin ceases to be made. It seemed possible that if the synthesis of involucrin, a critical marker of keratinocyte terminal differentiation, could be completely inhibited, this differentiation programme might be disrupted, and the malignant phenotype might then reappear in the non-malignant hybrids. This question was investigated further in the present paper. Total, and specific, inhibition of involucrin synthesis was indeed achieved by a sequential two-step antisense procedure, which might provide a systematic general method for the complete inactivation of other selected target genes.

scholarly journals Tumor-Derived Exosomes (TEX) and Their Role in Immuno-Oncology

2021 ◽  
Vol 22 (12) ◽  
pp. 6234
Author(s):  
Theresa Whiteside ◽  
Brenda Diergaarde ◽  
Chang-Sook Hong
Keyword(s):  
T Cells ◽  
Cancer Patients ◽  
Immune Cell ◽  
Parent Cell ◽  
Malignant Cells ◽  
Tumor Biopsy ◽  
Cellular Origin ◽  
Cell Functions

Extracellular vesicles (EVs) play a key role in health and disease, including cancer. Tumors produce a mix of EVs differing in size, cellular origin, biogenesis and molecular content. Small EVs (sEV) or exosomes are a subset of 30–150 nm (virus–size) vesicles originating from the multivesicular bodies (MVBs) and carrying a cargo that in its content and topography approximates that of a parent cell. Tumor-derived exosomes (TEX) present in all body fluids of cancer patients, are considered promising candidates for a liquid tumor biopsy. TEX also mediate immunoregulatory activities: they maintain a crosstalk between the tumor and various non-malignant cells, including immunocytes. Effects that EVs exert on immune cells may be immunosuppressive or immunostimulatory. Here, we review the available data for TEX interactions with immunocytes, focusing on strategies that allow isolation from plasma and separation of TEX from sEV produced by non-malignant cells. Immune effects mediated by either of the subsets can now be distinguished and measured. The approach has allowed for the comparison of molecular and functional profiles of the two sEV fractions in plasma of cancer patients. While TEX carried an excess of immunosuppressive proteins and inhibited immune cell functions in vitro and in vivo, the sEV derived from non-malignant cells, including CD3(+)T cells, were variably enriched in immunostimulatory proteins and could promote functions of immunocytes. Thus, sEV in plasma of cancer patients are heterogenous, representing a complex molecular network which is not evident in healthy donors’ plasma. Importantly, TEX appear to be able to reprogram functions of non-malignant CD3(+)T cells inducing them to produce CD3(+)sEV enriched in immunosuppressive proteins. Ratios of stimulatory/inhibitory proteins carried by TEX and by CD3(+)sEV derived from reprogrammed non-malignant cells vary broadly in patients and appear to negatively correlate with disease progression. Simultaneous capture from plasma and functional/molecular profiling of TEX and the CD3(+)sEV fractions allows for defining their role as cancer biomarkers and as monitors of cancer patients’ immune competence, respectively.

scholarly journals CDK13 upregulation-induced formation of the positive feedback loop among circCDK13, miR-212-5p/miR-449a and E2F5 contributes to prostate carcinogenesis

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Jin-Chun Qi ◽  
Zhan Yang ◽  
Tao Lin ◽  
Long Ma ◽  
Ya-Xuan Wang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Transcriptional Activation ◽  
Positive Feedback ◽  
Feedback Loop ◽  
Biological Effects ◽  
Therapeutic Benefit ◽  
Loss Of Function ◽  
Positive Feedback Loop

Abstract Background Both E2F transcription factor and cyclin-dependent kinases (CDKs), which increase or decrease E2F activity by phosphorylating E2F or its partner, are involved in the control of cell proliferation, and some circRNAs and miRNAs regulate the expression of E2F and CDKs. However, little is known about whether dysregulation among E2Fs, CDKs, circRNAs and miRNAs occurs in human PCa. Methods The expression levels of CDK13 in PCa tissues and different cell lines were determined by quantitative real-time PCR and Western blot analysis. In vitro and in vivo assays were preformed to explore the biological effects of CDK13 in PCa cells. Co-immunoprecipitation anlysis coupled with mass spectrometry was used to identify E2F5 interaction with CDK13. A CRISPR-Cas9 complex was used to activate endogenous CDK13 and circCDK13 expression. Furthermore, the mechanism of circCDK13 was investigated by using loss-of-function and gain-of-function assays in vitro and in vivo. Results Here we show that CDK13 is significantly upregulated in human PCa tissues. CDK13 depletion and overexpression in PCa cells decrease and increase, respectively, cell proliferation, and the pro-proliferation effect of CDK13 is strengthened by its interaction with E2F5. Mechanistically, transcriptional activation of endogenous CDK13, but not the forced expression of CDK13 by its expression vector, remarkably promotes E2F5 protein expression by facilitating circCDK13 formation. Further, the upregulation of E2F5 enhances CDK13 transcription and promotes circCDK13 biogenesis, which in turn sponges miR-212-5p/449a and thus relieves their repression of the E2F5 expression, subsequently leading to the upregulation of E2F5 expression and PCa cell proliferation. Conclusions These findings suggest that CDK13 upregulation-induced formation of the positive feedback loop among circCDK13, miR-212-5p/miR-449a and E2F5 is responsible for PCa development. Targeting this newly identified regulatory axis may provide therapeutic benefit against PCa progression and drug resistance.

scholarly journals An approach for the analysis of relapse and marrow reconstitution after autologous marrow transplantation using retrovirus-mediated gene transfer

Blood ◽  
1992 ◽  
Vol 79 (10) ◽  
pp. 2694-2700 ◽  
Author(s):  
DR Rill ◽  
RC Moen ◽  
M Buschle ◽  
C Bartholomew ◽  
NK Foreman ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Marrow Transplantation ◽  
Residual Disease ◽  
Marker Gene ◽  
Autologous Bone Marrow Transplantation ◽  
Autologous Bone Marrow ◽  
Disease Recurrence ◽  
Malignant Cells

Abstract Autologous bone marrow transplantation (ABMT) is widely used as treatment for malignant disease. Although the major cause of treatment failure is relapse, it is unknown if this arises entirely because of residual disease in the patient or whether contaminating cells in the rescuing marrow contribute. Attempts to purge marrow of its putative residual malignant cells may delay hematopoietic reconstitution and are of uncertain efficacy. We now describe how retrovirus-mediated gene transfer may be used to elucidate the source of relapse after ABMT for acute myeloid leukemia and to evaluate the efficacy of purging. Clonogenic myeloid leukemic blast cells in patient marrow can be transduced with the NeoR gene-containing helper-free retrovirus, LNL6, with an efficacy of 0% to 23.5% (mean, 10.5%). Transduced colonies grow in selective media and the presence of the marker gene can be confirmed in individual malignant colonies by polymerase chain reaction. If such malignant cells remain in harvested “remission” marrow, they will therefore be marked after exposure to LNL6. Detection of the marker gene in the malignant cells present at any later relapse would be firm evidence that residual disease contributed to disease recurrence, and would permit rapid subsequent evaluation of purging techniques. The technique also marks normal marrow progenitors from patients with acute myeloblastic leukemia. These colony-forming cells can be detected in long-term marrow cultures at a frequency of 1% to 18% for up to 10 weeks after exposure to the vector. Animal models and analysis of probability tables both suggest that these levels of marking in vitro are sufficient to provide information about the mechanisms of relapse and the biology of marrow regeneration in vivo. These preclinical data form part of the basis for current clinical studies of gene transfer into marrow before ABMT.

scholarly journals Inhibition of Kirsten-Ras reduces fibrosis and protects against renal dysfunction in a mouse model of chronic folic acid nephropathy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Lucy J. Newbury ◽  
Jui-Hui Wang ◽  
Gene Hung ◽  
Bruce M. Hendry ◽  
Claire C. Sharpe
Keyword(s):  
Folic Acid ◽  
Kidney Disease ◽  
Mouse Model ◽  
Renal Dysfunction ◽  
Antisense Oligonucleotides ◽  
Underlying Mechanism ◽  
Therapeutic Benefit ◽  
End Stage

Abstract Chronic Kidney Disease is a growing problem across the world and can lead to end-stage kidney disease and cardiovascular disease. Fibrosis is the underlying mechanism that leads to organ dysfunction, but as yet we have no therapeutics that can influence this process. Ras monomeric GTPases are master regulators that direct many of the cytokines known to drive fibrosis to downstream effector cascades. We have previously shown that K-Ras is a key isoform that drives fibrosis in the kidney. Here we demonstrate that K-Ras expression and activation are increased in rodent models of CKD. By knocking down expression of K-Ras using antisense oligonucleotides in a mouse model of chronic folic acid nephropathy we can reduce fibrosis by 50% and prevent the loss of renal function over 3 months. In addition, we have demonstrated in vitro and in vivo that reduction of K-Ras expression is associated with a reduction in Jag1 expression; we hypothesise this is the mechanism by which targeting K-Ras has therapeutic benefit. In conclusion, targeting K-Ras expression with antisense oligonucleotides in a mouse model of CKD prevents fibrosis and protects against renal dysfunction.

scholarly journals Regenerative potential of secretome from dental stem cells: a systematic review of preclinical studies

2018 ◽  
Vol 29 (3) ◽  
pp. 321-332 ◽  
Author(s):  
Suleiman Alhaji Muhammad ◽  
Norshariza Nordin ◽  
Sharida Fakurazi
Keyword(s):  
Systematic Review ◽  
Stem Cells ◽  
Stem Cell ◽  
Animal Models ◽  
Conditioned Medium ◽  
Tissue Regeneration ◽  
Therapeutic Benefit ◽  
Risk Of Bias ◽  
Preclinical Studies

AbstractInjury to tissues is a major clinical challenge due to the limited regenerative capacity of endogenous cells. Stem cell therapy is evolving rapidly as an alternative for tissue regeneration. However, increasing evidence suggests that the regenerative ability of stem cells is mainly mediated by paracrine actions of secretome that are generally secreted by the cells. We aimed to systematically evaluate the efficacy of dental stem cell (DSC)-conditioned medium inin vivoanimal models of various tissue defects. A total of 15 eligible studies was included by searching Pubmed, Scopus and Medline databases up to August 2017. The risk of bias was assessed using the Systematic Review Centre for Laboratory Animal Experimentation risk of bias tool. Of 15 studies, seven reported the therapeutic benefit of the conditioned medium on neurological diseases and three reported on joint/bone-related defects. Two interventions were on liver diseases, whereas the remaining three addressed myocardial infarction and reperfusion, lung injury and diabetes. Nine studies were performed using mouse models and the remaining six studies used rat models. The methodological quality of the studies was low, as most of the key elements required in reports of preclinical studies were not reported. The findings of this review suggested that conditioned medium from DSCs improved tissue regeneration and functional recovery. This current review strengthens the therapeutic benefit of cell-free product for tissue repair in animal models. A well-planned study utilizing validated outcome measures and long-term safety studies are required for possible translation to clinical trials.

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