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Tenascin-C promotes melanoma progression by maintaining the ABCB5-positive side population.

Fukunaga-Kalabis M, Martinez G, Nguyen TK, Kim D, Santiago-Walker A, Roesch A, Herlyn M - Oncogene (2010)

Bottom Line: Recent studies indicate that TNC has a role within the stem cell niche.Downmodulation of TNC by shRNA lentiviruses significantly decreased the growth of melanoma spheres.Knockdown of TNC dramatically decreased the SP fraction in melanoma spheres and lowered their resistance to doxorubicin treatment, likely because of the downregulation of multiple ATP-binding cassette (ABC) transporters, including ABCB5.

View Article: PubMed Central - PubMed

Affiliation: Molecular and Cellular Oncogenesis Program, Division of Molecular and Cellular Biology, The Wistar Institute, Philadelphia, PA 19104, USA.

ABSTRACT
Tenascin-C (TNC) is highly expressed in melanoma; however, little is known about its functions. Recent studies indicate that TNC has a role within the stem cell niche. We hypothesized that TNC creates a specific environment for melanoma cells to show a stem cell-like phenotype, promoting tumor growth and evading conventional therapies. TNC expression was strongly upregulated in melanoma cells grown as 3D spheres (enriched for stem-like cells) when compared to adherent cells. Downmodulation of TNC by shRNA lentiviruses significantly decreased the growth of melanoma spheres. The incidence of pulmonary metastases after intravenous injection of TNC knockdown cells was significantly lower in NOD/SCID IL2Rγ() mice compared with control cells. Melanoma spheres contain an increased number of side population (SP) cells, which show stem cell characteristics, and have the potential for drug resistance due to their high efflux capacity. Knockdown of TNC dramatically decreased the SP fraction in melanoma spheres and lowered their resistance to doxorubicin treatment, likely because of the downregulation of multiple ATP-binding cassette (ABC) transporters, including ABCB5. These data suggest that TNC is critical in melanoma progression as it mediates protective signals in the therapy-resistant population of melanoma.

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Related in: MedlinePlus

TNC knockdown decreases growth of melanoma spheres(A) Immunoblot of WM3734 cells infected with TNC lentiviral shRNAs to two target sequences (sh_TNC_A and sh_TNC_C). A non-targeted shRNA (sh_Cont) was used as control. β-actin indicated equal loading. (B) Growth of WM3734 cells transduced with TNC shRNA as adherent cultures (left) and as spheres (right) was measured by MTS assay. OD 490 of each time point was normalized to Day 1. Data represent the mean ± SD (n=4). *, p<0.05 when compared to sh_Cont cells.
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Figure 2: TNC knockdown decreases growth of melanoma spheres(A) Immunoblot of WM3734 cells infected with TNC lentiviral shRNAs to two target sequences (sh_TNC_A and sh_TNC_C). A non-targeted shRNA (sh_Cont) was used as control. β-actin indicated equal loading. (B) Growth of WM3734 cells transduced with TNC shRNA as adherent cultures (left) and as spheres (right) was measured by MTS assay. OD 490 of each time point was normalized to Day 1. Data represent the mean ± SD (n=4). *, p<0.05 when compared to sh_Cont cells.

Mentions: TNC promotes overall survival of neuronal cells after cell detachment (Jones et al., 1997) by preventing anoikis (Marchionini et al., 2003). We determined whether TNC regulates the growth of melanoma spheres. WM3734 cells, infected with lentivirus encoding shRNAs to TNC (sh_TNC_A and sh_TNC_C), showed an 80-90% decrease in TNC protein expression when compared to control vector-infected cells (sh_Cont) (Figure 2A). Attenuation of TNC did not affect the growth of WM3734 adherent cells over a three-day time course (Figure 2B, left panel). In contrast, sh_TNC induced a significant decrease in the growth of WM3734 spheres (Figure 2B, right panel). This observation suggests that TNC maintains cell survival and growth of melanoma sphere cells.


Tenascin-C promotes melanoma progression by maintaining the ABCB5-positive side population.

Fukunaga-Kalabis M, Martinez G, Nguyen TK, Kim D, Santiago-Walker A, Roesch A, Herlyn M - Oncogene (2010)

TNC knockdown decreases growth of melanoma spheres(A) Immunoblot of WM3734 cells infected with TNC lentiviral shRNAs to two target sequences (sh_TNC_A and sh_TNC_C). A non-targeted shRNA (sh_Cont) was used as control. β-actin indicated equal loading. (B) Growth of WM3734 cells transduced with TNC shRNA as adherent cultures (left) and as spheres (right) was measured by MTS assay. OD 490 of each time point was normalized to Day 1. Data represent the mean ± SD (n=4). *, p<0.05 when compared to sh_Cont cells.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2991494&req=5

Figure 2: TNC knockdown decreases growth of melanoma spheres(A) Immunoblot of WM3734 cells infected with TNC lentiviral shRNAs to two target sequences (sh_TNC_A and sh_TNC_C). A non-targeted shRNA (sh_Cont) was used as control. β-actin indicated equal loading. (B) Growth of WM3734 cells transduced with TNC shRNA as adherent cultures (left) and as spheres (right) was measured by MTS assay. OD 490 of each time point was normalized to Day 1. Data represent the mean ± SD (n=4). *, p<0.05 when compared to sh_Cont cells.
Mentions: TNC promotes overall survival of neuronal cells after cell detachment (Jones et al., 1997) by preventing anoikis (Marchionini et al., 2003). We determined whether TNC regulates the growth of melanoma spheres. WM3734 cells, infected with lentivirus encoding shRNAs to TNC (sh_TNC_A and sh_TNC_C), showed an 80-90% decrease in TNC protein expression when compared to control vector-infected cells (sh_Cont) (Figure 2A). Attenuation of TNC did not affect the growth of WM3734 adherent cells over a three-day time course (Figure 2B, left panel). In contrast, sh_TNC induced a significant decrease in the growth of WM3734 spheres (Figure 2B, right panel). This observation suggests that TNC maintains cell survival and growth of melanoma sphere cells.

Bottom Line: Recent studies indicate that TNC has a role within the stem cell niche.Downmodulation of TNC by shRNA lentiviruses significantly decreased the growth of melanoma spheres.Knockdown of TNC dramatically decreased the SP fraction in melanoma spheres and lowered their resistance to doxorubicin treatment, likely because of the downregulation of multiple ATP-binding cassette (ABC) transporters, including ABCB5.

View Article: PubMed Central - PubMed

Affiliation: Molecular and Cellular Oncogenesis Program, Division of Molecular and Cellular Biology, The Wistar Institute, Philadelphia, PA 19104, USA.

ABSTRACT
Tenascin-C (TNC) is highly expressed in melanoma; however, little is known about its functions. Recent studies indicate that TNC has a role within the stem cell niche. We hypothesized that TNC creates a specific environment for melanoma cells to show a stem cell-like phenotype, promoting tumor growth and evading conventional therapies. TNC expression was strongly upregulated in melanoma cells grown as 3D spheres (enriched for stem-like cells) when compared to adherent cells. Downmodulation of TNC by shRNA lentiviruses significantly decreased the growth of melanoma spheres. The incidence of pulmonary metastases after intravenous injection of TNC knockdown cells was significantly lower in NOD/SCID IL2Rγ() mice compared with control cells. Melanoma spheres contain an increased number of side population (SP) cells, which show stem cell characteristics, and have the potential for drug resistance due to their high efflux capacity. Knockdown of TNC dramatically decreased the SP fraction in melanoma spheres and lowered their resistance to doxorubicin treatment, likely because of the downregulation of multiple ATP-binding cassette (ABC) transporters, including ABCB5. These data suggest that TNC is critical in melanoma progression as it mediates protective signals in the therapy-resistant population of melanoma.

Show MeSH
Related in: MedlinePlus