Logo: to the web site of Uppsala University

uu.sePublications from Uppsala University
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
MYCN induces cell-specific tumorigenic growth in RB1-proficient human retinal organoid and chicken retina models of retinoblastoma
(Hallböök)
(Hallböök)ORCID iD: 0000-0002-1459-0377
(Hallböök)
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Hallböök: Stem cells, Retinal Development and Regeneration. (Hallböök)
Show others and affiliations
2022 (English)In: Oncogenesis, E-ISSN 2157-9024, Vol. 11, no 1Article in journal (Refereed) Published
Abstract [en]

Retinoblastoma is a rare, intraocular paediatric cancer that originates in the neural retina and is most frequently caused by bi-allelic loss of RB1 gene function. Other oncogenic mutations, such as amplification and increased expression of the MYCN gene, have been found even with proficient RB1 function. In this study, we investigated whether MYCN over-expression can drive carcinogenesis independently of RB1 loss-of-function mutations. The aim was to elucidate the events that result in carcinogenesis and identify the cancer cell-of-origin. We studied the chicken retina, a well-established model for studying retinal neurogenesis, and generated over-expression of MYCN by in ovo electroporation. In parallel, we established an equivalent human stem cell-derived retinal organoid (retinoid) model system. We found that over-expression of MYCN induced tumorigenic growth with high frequency in RB1-proficient chicken retinas and human retinoids. In both systems, the tumorigenic cells expressed markers for undifferentiated cone photoreceptor/horizontal cell progenitors. The over-expression resulted in metastatic retinoblastoma within 7-9 weeks in chicken. MYCN cells could be grown in vitro and, when orthotopically injected, formed tumours that infiltrated the sclera and optic nerve and expressed markers for undifferentiated cones. Investigation of the tumour cell phenotype determined that the potential for neoplastic growth was embryonic stage-dependent and featured a cell-specific resistance to apoptosis in the cone/horizontal cell lineage, but not in ganglion or amacrine cells. We conclude that MYCN over-expression is sufficient to drive tumorigenesis and that a cell-specific resistance to apoptosis in the cone/horizontal cell lineage mediates the cancer phenotype.

Place, publisher, year, edition, pages
Springer Nature Springer Nature, 2022. Vol. 11, no 1
National Category
Neurosciences
Identifiers
URN: urn:nbn:se:uu:diva-315611DOI: 10.1038/s41389-022-00409-3ISI: 000814269100001PubMedID: 35729105OAI: oai:DiVA.org:uu-315611DiVA, id: diva2:1074890
Available from: 2017-02-16 Created: 2017-02-16 Last updated: 2024-01-15Bibliographically approved
In thesis
1. Keeping up with retinal photoreceptors and horizontal cells: Labelling and mapping of cells in the normal and diseased embryonic chicken retina
Open this publication in new window or tab >>Keeping up with retinal photoreceptors and horizontal cells: Labelling and mapping of cells in the normal and diseased embryonic chicken retina
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The childhood eye cancer retinoblastoma originates from the retina and its development is initiated while the foetus is in the uterus. Retinoblastoma has a reported incidence of 1 in 15-18 000 live births, and approximately 90% of all patients are diagnosed before the age of 5. The occurrence of retinoblastoma is usually detected by the parents and the most frequent symptoms are leukocoria (white pupillary reflex), strabismus (squinting) or if the child complains of visual problems. Retinoblastoma is diagnosed by examination under anaesthesia and documentation by RetCam. It is treated with various cytostatic agents, or by laser. If the treatment is unsuccessful, or there is a risk that the tumour cells will spread and form metastases, the eye is removed.

Previous studies have indicated that the cell type from which the tumour arises, the cell-of-origin, may be the cone photoreceptors and/or their immediate interneuron, the horizontal cells. Determining the cell-of-origin for retinoblastoma is an important goal, however, understanding the molecular mechanisms that distinguish the photoreceptors and the horizontal cells from the other retinal cells may prove just as important for understanding this disease.

The aim of my project has been to develop, optimise and validate methods to label, map and target expression to photoreceptors and horizontal cells in the chicken embryonic retina. We have successfully established several methods that test the expression pattern of conserved, regulatory DNA sequences, and have performed short- and long-term expression of various genes that have been reported to be involved in cell cycle regulation and cell fate determination. One of my most important findings was that a region from the RXRγ gene allowed us to specifically target the photoreceptors and horizontal cells. Our previous knowledge, together with the newly established tools, puts us an important step closer towards understanding the development and behaviour of the retinal photoreceptors and horizontal cells, however, further studies are of course needed.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2017. p. 62
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 1651-6206 ; 1302
Keywords
Chicken, electroporation, horizontal cells, photoreceptors, retina, piggyBac
National Category
Neurosciences
Identifiers
urn:nbn:se:uu:diva-315655 (URN)978-91-554-9825-2 (ISBN)
Public defence
2017-04-07, B21, BMC, Husargatan 3, Uppsala, 09:15 (English)
Opponent
Supervisors
Available from: 2017-03-10 Created: 2017-02-17 Last updated: 2018-01-13
2. Modulation of retinal progenitors: A bird’s-eye view of retinal regeneration and disease
Open this publication in new window or tab >>Modulation of retinal progenitors: A bird’s-eye view of retinal regeneration and disease
2022 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The cell populations of the retina and their intricate organization provide us with one of the most important senses – vision. All retinal cell populations are derived from a common progenitor pool as a result of tight regulation of proliferation, differentiation, dedifferentiation, and programmed cell death. Dysregulation of these processes, or injury to the retina, can result in loss of vision or in certain cases even cancer – i.e. retinoblastoma. Understanding the mechanistic basis of these processes allows for modeling cancer and retinal regeneration. To this purpose, the embryonic chicken retina, and cultures thereof, were subjected to pharmacological intervention and modulation of gene expression. To validate findings in a human model, some studies were extended with the use of human cell cultures or retinal organoids derived from human embryonic stem cells. The focus was on the late events of retinal neurogenesis. 

In Paper I, we investigated endothelins as potential modulators of injury-induced retinal regeneration, which is performed by Müller cells in certain species. Injured Müller cells will dedifferentiate and return to the progenitor pool. We found that stimulation of the endothelin receptor induces dedifferentiation by transactivation of the epidermal growth factor receptor and subsequent activation of the MAPK-signaling pathway, in both chicken Müller cells and an immortalized cell line with Müller cell properties. Our findings show that endothelins have potential as possible regulators of the injury response and subsequent regeneration of lost neurons performed by Müller cells.

In Paper II, the Nolz1 transcription factor and its regulation of retinal neurogenesis was explored. We show that Nolz1 acts as a negative regulator of the cell cycle in retinal progenitors, and hinders bipolar cell specification by Lim3 gene repression.

In Paper III, we investigated the final neurogenic mitosis of the cone photoreceptor/horizontal cell progenitor (cPR/HC) lineage. MYCN-overexpression in a functional RB1 setting produced neoplastic growth in a cell-type and developmental-stage specific manner. The cPR/HC-lineage alone escaped apoptosis and continued proliferation both in human retinal organoids and embryonic chicken retina. Our findings have implications for the etiology of retinoblastoma and show that MYCN alone can induce cancerogenesis. The tumors arise as a result if intrinsic properties of the cPR/HC-lineage, which have not been observed in other retinal populations. 

Taken together, this thesis gives novel knowledge regarding the late events of retinal neurogenesis, cell-type specification, and the inherent properties of certain retinal progenitor lineages in the healthy and diseased retina.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2022. p. 75
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 1651-6206 ; 1839
Keywords
Developmental neurobiology, Retinoblastoma, MYCN, Cone photoreceptor, Nolz1, Endothelin, Müller cells
National Category
Cell and Molecular Biology Developmental Biology
Identifiers
urn:nbn:se:uu:diva-470844 (URN)978-91-513-1490-7 (ISBN)
Public defence
2022-06-01, B22, Husargatan 3, Uppsala, 09:15 (English)
Opponent
Supervisors
Available from: 2022-05-09 Created: 2022-04-06 Last updated: 2022-06-15
3. Models of Retinal Development and Disease
Open this publication in new window or tab >>Models of Retinal Development and Disease
2022 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

For a model of a human disease to be valid and useful, it is important that key genotypic and phenotypic traits are shared between model system and human. The work in this thesis has been focused on generating new and characterizing spontaneous models of three genetic disorders affecting the retina: retinoblastoma, a childhood cancer with its origin in the fetal retina, Stargardt disease, a juvenile form of macular degeneration, and Bardet-Biedl syndrome, a pleiotropic ciliopathy featuring retinal degeneration.

In Paper I, we generated two novel models of MYCN-driven retinoblastoma, in developing chicken retinas and in human retinal organoids, in order to identify its cell of origin and to determine whether MYCN is sufficient in driving tumorigenesis. We found that MYCN was indeed sufficient and that the expression was uniquely tolerated by the cone and horizontal cell progenitor which survived and proliferated anachronistically. The results from our models are in alignment with observations that MYCN-driven retinoblastoma results in a more anaplastic and aggressive form of the cancer and we propose that the fate-restricted progenitor for cones and horizontal cells is its cell of origin.

In Paper II, we analyzed the effects of a novel, spontaneous model of ABCA4-mediated Stargardt disease in Labrador retrievers and found that dogs homozygous for the mutation exhibited visual impairment and photoreceptor degeneration. Cone photoreceptors were scarce and the retinal pigment epithelium autofluorescent, indicative of lipofuscin accumulation, a hallmark of Stargardt disease. The phenotype and its etiology in this model are akin to human Stargardt disease.

In Paper III, we investigated whether a spontaneous mutation in the TTC8 gene resulted in syndromic Bardet-Biedl syndrome in golden retrievers. We found that, in addition to progressive photoreceptor degeneration and visual impairment, the TTC8 mutation resulted in pleiotropic clinical signs of Bardet-Biedl syndrome with great inter-individual variation, congruent with Bardet-Biedl syndrome in humans.

We find that the models described in this thesis are representative of the corresponding genetic disorders in human and that they could be of value for hypothesis generation (in chicken), experimental gene therapy (in dog), and as a human system to test pharmacological interventions (retinal organoids).

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2022. p. 55
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 1651-6206 ; 1862
Keywords
Developmental neurobiology, retinal organoids, retinoblastoma, MYCN, Stargardt disease, Bardet-Biedl syndrome, model systems
National Category
Cell and Molecular Biology Developmental Biology
Identifiers
urn:nbn:se:uu:diva-481210 (URN)978-91-513-1577-5 (ISBN)
Public defence
2022-10-07, Room A1:107a, BMC, Husargatan 3, Uppsala, 13:15 (English)
Opponent
Supervisors
Available from: 2022-09-15 Created: 2022-08-24 Last updated: 2022-09-15

Open Access in DiVA

fulltext(987 kB)161 downloads
File information
File name FULLTEXT01.pdfFile size 987 kBChecksum SHA-512
dc9c7c6eb3040f9a53d4fc96cc6dee99a0a6720554c5289d87f74d7ec83c1d709c02ab0106ca8fb5289c9a549577c99988951d2b9a7324562b570f6b7dcde102
Type fulltextMimetype application/pdf

Other links

Publisher's full textPubMed

Authority records

Blixt, MariaHellsand, MinasKonjusha, DardanZhang, HanzhaoRafati, NimaTararuk, TatsianaRing, HenrikHallböök, Finn

Search in DiVA

By author/editor
Blixt, MariaHellsand, MinasKonjusha, DardanZhang, HanzhaoRafati, NimaTararuk, TatsianaRing, HenrikHallböök, Finn
By organisation
Hallböök: Stem cells, Retinal Development and RegenerationDepartment of Medical Biochemistry and MicrobiologyScience for Life Laboratory, SciLifeLab
In the same journal
Oncogenesis
Neurosciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 161 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 631 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf