Limits...
Reversible adaptive plasticity: a mechanism for neuroblastoma cell heterogeneity and chemo-resistance.

Chakrabarti L, Abou-Antoun T, Vukmanovic S, Sandler AD - Front Oncol (2012)

Bottom Line: The AI tumorspheres were found to be more resistant to chemotherapy and proliferated slower in vitro compared to the AD cells.Our results demonstrate that neuroblastoma cells are plastic, dynamic, and may optimize their ability to survive by changing their phenotype.Phenotypic switching appears to be an adaptive mechanism to unfavorable selection pressure and could explain the phenotypic and functional heterogeneity of neuroblastoma.

View Article: PubMed Central - PubMed

Affiliation: The Joseph E. Robert Center for Surgical Care, Children's National Medical Center Washington, DC, USA.

ABSTRACT
We describe a novel form of tumor cell plasticity characterized by reversible adaptive plasticity in murine and human neuroblastoma. Two cellular phenotypes were defined by their ability to exhibit adhered, anchorage dependent (AD) or sphere forming, anchorage independent (AI) growth. The tumor cells could transition back and forth between the two phenotypes and the transition was dependent on the culture conditions. Both cell phenotypes exhibited stem-like features such as expression of nestin, self-renewal capacity, and mesenchymal differentiation potential. The AI tumorspheres were found to be more resistant to chemotherapy and proliferated slower in vitro compared to the AD cells. Identification of specific molecular markers like MAP2, β-catenin, and PDGFRβ enabled us to characterize and observe both phenotypes in established mouse tumors. Irrespective of the phenotype originally implanted in mice, tumors grown in vivo show phenotypic heterogeneity in molecular marker signatures and are indistinguishable in growth or histologic appearance. Similar molecular marker heterogeneity was demonstrated in primary human tumor specimens. Chemotherapy or growth factor receptor inhibition slowed tumor growth in mice and promoted initial loss of AD or AI heterogeneity, respectively. Simultaneous targeting of both phenotypes led to further tumor growth delay with emergence of new unique phenotypes. Our results demonstrate that neuroblastoma cells are plastic, dynamic, and may optimize their ability to survive by changing their phenotype. Phenotypic switching appears to be an adaptive mechanism to unfavorable selection pressure and could explain the phenotypic and functional heterogeneity of neuroblastoma.

No MeSH data available.


Related in: MedlinePlus

Reversible adaptive plasticity of neuroblastoma cell lines. (A) Neuro2a, IMR-32, and SK-N-SH cells cultured in DMEM + 10% FBS (D10) or Neurocult complete (NC) medium formed a monolayer of anchorage dependent (AD) adhered cells or anchorage independent (AI) tumorspheres, respectively. (B) Dissociated AI cells, originally derived from AD cells readily reversed their phenotype and formed AD monolayers when cultured in the D10 medium. Images acquired with 20× objective.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3412992&req=5

Figure 1: Reversible adaptive plasticity of neuroblastoma cell lines. (A) Neuro2a, IMR-32, and SK-N-SH cells cultured in DMEM + 10% FBS (D10) or Neurocult complete (NC) medium formed a monolayer of anchorage dependent (AD) adhered cells or anchorage independent (AI) tumorspheres, respectively. (B) Dissociated AI cells, originally derived from AD cells readily reversed their phenotype and formed AD monolayers when cultured in the D10 medium. Images acquired with 20× objective.

Mentions: Mouse (Neuro2a) and human (IMR-32 and SK-N-SH) cell lines, cultured in D10 media exhibited an AD phenotype characterized by growth in a monolayer. Transfer to serum-free NeuroCult complete (NC) media supplemented with EGF and FGF induced an AI phenotype, characterized by detachment of cells and formation of floating tumorspheres (Figure 1A). AI cells from all the cell lines readily reformed tumorspheres when cultured in NC media, but adhered and formed monolayers when cultured in the D10 media (Figure 1B). Thus, neuroblastoma cultures facing distinct growth promoting conditions can transition to and from two distinct phenotypes which are defined by tumor cell adherence characteristics. We have observed a similar phenomenon of adaptive growth patterns in melanoma and rhabdomyosarcoma cell lines (Unpublished data).


Reversible adaptive plasticity: a mechanism for neuroblastoma cell heterogeneity and chemo-resistance.

Chakrabarti L, Abou-Antoun T, Vukmanovic S, Sandler AD - Front Oncol (2012)

Reversible adaptive plasticity of neuroblastoma cell lines. (A) Neuro2a, IMR-32, and SK-N-SH cells cultured in DMEM + 10% FBS (D10) or Neurocult complete (NC) medium formed a monolayer of anchorage dependent (AD) adhered cells or anchorage independent (AI) tumorspheres, respectively. (B) Dissociated AI cells, originally derived from AD cells readily reversed their phenotype and formed AD monolayers when cultured in the D10 medium. Images acquired with 20× objective.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3412992&req=5

Figure 1: Reversible adaptive plasticity of neuroblastoma cell lines. (A) Neuro2a, IMR-32, and SK-N-SH cells cultured in DMEM + 10% FBS (D10) or Neurocult complete (NC) medium formed a monolayer of anchorage dependent (AD) adhered cells or anchorage independent (AI) tumorspheres, respectively. (B) Dissociated AI cells, originally derived from AD cells readily reversed their phenotype and formed AD monolayers when cultured in the D10 medium. Images acquired with 20× objective.
Mentions: Mouse (Neuro2a) and human (IMR-32 and SK-N-SH) cell lines, cultured in D10 media exhibited an AD phenotype characterized by growth in a monolayer. Transfer to serum-free NeuroCult complete (NC) media supplemented with EGF and FGF induced an AI phenotype, characterized by detachment of cells and formation of floating tumorspheres (Figure 1A). AI cells from all the cell lines readily reformed tumorspheres when cultured in NC media, but adhered and formed monolayers when cultured in the D10 media (Figure 1B). Thus, neuroblastoma cultures facing distinct growth promoting conditions can transition to and from two distinct phenotypes which are defined by tumor cell adherence characteristics. We have observed a similar phenomenon of adaptive growth patterns in melanoma and rhabdomyosarcoma cell lines (Unpublished data).

Bottom Line: The AI tumorspheres were found to be more resistant to chemotherapy and proliferated slower in vitro compared to the AD cells.Our results demonstrate that neuroblastoma cells are plastic, dynamic, and may optimize their ability to survive by changing their phenotype.Phenotypic switching appears to be an adaptive mechanism to unfavorable selection pressure and could explain the phenotypic and functional heterogeneity of neuroblastoma.

View Article: PubMed Central - PubMed

Affiliation: The Joseph E. Robert Center for Surgical Care, Children's National Medical Center Washington, DC, USA.

ABSTRACT
We describe a novel form of tumor cell plasticity characterized by reversible adaptive plasticity in murine and human neuroblastoma. Two cellular phenotypes were defined by their ability to exhibit adhered, anchorage dependent (AD) or sphere forming, anchorage independent (AI) growth. The tumor cells could transition back and forth between the two phenotypes and the transition was dependent on the culture conditions. Both cell phenotypes exhibited stem-like features such as expression of nestin, self-renewal capacity, and mesenchymal differentiation potential. The AI tumorspheres were found to be more resistant to chemotherapy and proliferated slower in vitro compared to the AD cells. Identification of specific molecular markers like MAP2, β-catenin, and PDGFRβ enabled us to characterize and observe both phenotypes in established mouse tumors. Irrespective of the phenotype originally implanted in mice, tumors grown in vivo show phenotypic heterogeneity in molecular marker signatures and are indistinguishable in growth or histologic appearance. Similar molecular marker heterogeneity was demonstrated in primary human tumor specimens. Chemotherapy or growth factor receptor inhibition slowed tumor growth in mice and promoted initial loss of AD or AI heterogeneity, respectively. Simultaneous targeting of both phenotypes led to further tumor growth delay with emergence of new unique phenotypes. Our results demonstrate that neuroblastoma cells are plastic, dynamic, and may optimize their ability to survive by changing their phenotype. Phenotypic switching appears to be an adaptive mechanism to unfavorable selection pressure and could explain the phenotypic and functional heterogeneity of neuroblastoma.

No MeSH data available.


Related in: MedlinePlus