Limits...
The orphan tyrosine kinase receptor, ROR2, mediates Wnt5A signaling in metastatic melanoma.

O'Connell MP, Fiori JL, Xu M, Carter AD, Frank BP, Camilli TC, French AD, Dissanayake SK, Indig FE, Bernier M, Taub DD, Hewitt SM, Weeraratna AT - Oncogene (2009)

Bottom Line: We show here that increases in Wnt5A cause increases in ROR2 expression, as well as the PKC-dependent, clathrin-mediated internalization of ROR2.WNT5A knockdown by siRNA decreases ROR2 expression, but silencing of ROR2 has no effect on WNT5A levels.ROR2 knockdown does, however, result in a decrease in signaling downstream of Wnt5A.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.

ABSTRACT
Tyrosine kinase receptors represent targets of great interest for cancer therapy. Here we show, for the first time, the importance of the orphan tyrosine kinase receptor, ROR2, in melanoma progression. Using melanoma tissue microarrays, we show that ROR2 is expressed predominantly in metastatic melanoma. As ROR2 has been shown to specifically interact with the non-canonical Wnt ligand, Wnt5A, this corroborates our earlier data implicating Wnt5A as a mediator of melanoma metastasis. We show here that increases in Wnt5A cause increases in ROR2 expression, as well as the PKC-dependent, clathrin-mediated internalization of ROR2. WNT5A knockdown by siRNA decreases ROR2 expression, but silencing of ROR2 has no effect on WNT5A levels. ROR2 knockdown does, however, result in a decrease in signaling downstream of Wnt5A. Using in vitro and in vivo metastasis assays, we show that ROR2 is necessary for the Wnt5A-mediated metastasis of melanoma cells. These data imply that ROR2 may represent a novel target for melanoma therapy.

Show MeSH

Related in: MedlinePlus

ROR2 expression in human melanomaStaining of a melanoma tissue microarray demonstrates that the majority of primary melanomas do not express ROR2 (A), whereas subcutaneous or visceral metastases of melanoma stained very strongly for ROR2 in the cytoplasm and nucleus (B, arrows demonstrate nuclear staining). Lymph node metastases for the most part had very light staining of ROR2, and in these specimens ROR2 appeared to be largely at the membrane of the cell (C, arrows). Overall staining results are represented as percentage of samples positive per group (D). The increase in ROR2 expression in metastatic melanoma as compared to primary melanoma is significant to p<0.0001.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2803338&req=5

Figure 1: ROR2 expression in human melanomaStaining of a melanoma tissue microarray demonstrates that the majority of primary melanomas do not express ROR2 (A), whereas subcutaneous or visceral metastases of melanoma stained very strongly for ROR2 in the cytoplasm and nucleus (B, arrows demonstrate nuclear staining). Lymph node metastases for the most part had very light staining of ROR2, and in these specimens ROR2 appeared to be largely at the membrane of the cell (C, arrows). Overall staining results are represented as percentage of samples positive per group (D). The increase in ROR2 expression in metastatic melanoma as compared to primary melanoma is significant to p<0.0001.

Mentions: ROR2 expression was examined across a human melanoma tissue microarray (NCI Tissue Array Research Program, Bethesda, MD). Wnt5A expression is stronger in metastatic tissues, although it is also present in a heterogenous manner in primary tumors (Dissanayake et al., 2008). Our results demonstrate that ROR2 expression was absent in 28/48 primary melanomas (Figure 1A), weakly positive in the cytoplasm in 14 (1+) samples and strongly positive in 6 samples (2–3+). Four out of 31 lymph node metastases were negative for ROR2, 16 were weakly positive and 11 were positive. The pattern was most dramatic in other types of metastatic melanoma (comprised of both subcutaneous metastases and visceral metastases), as we have previously noted with Wnt5A (Dissanayake et al., 2008). In ROR2 positive visceral metastases (Figure 1B), staining appeared to be both cytoplasmic and could also be found in the nuclear or perinuclear region (Figure 1B, arrow). In the positive lymph node metastases, the location of ROR2 was largely at the membrane of the cells (Figure 1C, arrows). There were no visceral or subcutaneous metastases that were negative for ROR2, only 4 that were weakly positive, and the remaining 44 were strongly positive. These values are expressed as percentages in Figure 1D. χ2 analysis demonstrates that ROR2 expression is significantly increased in metastatic melanoma (p<0.001).


The orphan tyrosine kinase receptor, ROR2, mediates Wnt5A signaling in metastatic melanoma.

O'Connell MP, Fiori JL, Xu M, Carter AD, Frank BP, Camilli TC, French AD, Dissanayake SK, Indig FE, Bernier M, Taub DD, Hewitt SM, Weeraratna AT - Oncogene (2009)

ROR2 expression in human melanomaStaining of a melanoma tissue microarray demonstrates that the majority of primary melanomas do not express ROR2 (A), whereas subcutaneous or visceral metastases of melanoma stained very strongly for ROR2 in the cytoplasm and nucleus (B, arrows demonstrate nuclear staining). Lymph node metastases for the most part had very light staining of ROR2, and in these specimens ROR2 appeared to be largely at the membrane of the cell (C, arrows). Overall staining results are represented as percentage of samples positive per group (D). The increase in ROR2 expression in metastatic melanoma as compared to primary melanoma is significant to p<0.0001.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2803338&req=5

Figure 1: ROR2 expression in human melanomaStaining of a melanoma tissue microarray demonstrates that the majority of primary melanomas do not express ROR2 (A), whereas subcutaneous or visceral metastases of melanoma stained very strongly for ROR2 in the cytoplasm and nucleus (B, arrows demonstrate nuclear staining). Lymph node metastases for the most part had very light staining of ROR2, and in these specimens ROR2 appeared to be largely at the membrane of the cell (C, arrows). Overall staining results are represented as percentage of samples positive per group (D). The increase in ROR2 expression in metastatic melanoma as compared to primary melanoma is significant to p<0.0001.
Mentions: ROR2 expression was examined across a human melanoma tissue microarray (NCI Tissue Array Research Program, Bethesda, MD). Wnt5A expression is stronger in metastatic tissues, although it is also present in a heterogenous manner in primary tumors (Dissanayake et al., 2008). Our results demonstrate that ROR2 expression was absent in 28/48 primary melanomas (Figure 1A), weakly positive in the cytoplasm in 14 (1+) samples and strongly positive in 6 samples (2–3+). Four out of 31 lymph node metastases were negative for ROR2, 16 were weakly positive and 11 were positive. The pattern was most dramatic in other types of metastatic melanoma (comprised of both subcutaneous metastases and visceral metastases), as we have previously noted with Wnt5A (Dissanayake et al., 2008). In ROR2 positive visceral metastases (Figure 1B), staining appeared to be both cytoplasmic and could also be found in the nuclear or perinuclear region (Figure 1B, arrow). In the positive lymph node metastases, the location of ROR2 was largely at the membrane of the cells (Figure 1C, arrows). There were no visceral or subcutaneous metastases that were negative for ROR2, only 4 that were weakly positive, and the remaining 44 were strongly positive. These values are expressed as percentages in Figure 1D. χ2 analysis demonstrates that ROR2 expression is significantly increased in metastatic melanoma (p<0.001).

Bottom Line: We show here that increases in Wnt5A cause increases in ROR2 expression, as well as the PKC-dependent, clathrin-mediated internalization of ROR2.WNT5A knockdown by siRNA decreases ROR2 expression, but silencing of ROR2 has no effect on WNT5A levels.ROR2 knockdown does, however, result in a decrease in signaling downstream of Wnt5A.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.

ABSTRACT
Tyrosine kinase receptors represent targets of great interest for cancer therapy. Here we show, for the first time, the importance of the orphan tyrosine kinase receptor, ROR2, in melanoma progression. Using melanoma tissue microarrays, we show that ROR2 is expressed predominantly in metastatic melanoma. As ROR2 has been shown to specifically interact with the non-canonical Wnt ligand, Wnt5A, this corroborates our earlier data implicating Wnt5A as a mediator of melanoma metastasis. We show here that increases in Wnt5A cause increases in ROR2 expression, as well as the PKC-dependent, clathrin-mediated internalization of ROR2. WNT5A knockdown by siRNA decreases ROR2 expression, but silencing of ROR2 has no effect on WNT5A levels. ROR2 knockdown does, however, result in a decrease in signaling downstream of Wnt5A. Using in vitro and in vivo metastasis assays, we show that ROR2 is necessary for the Wnt5A-mediated metastasis of melanoma cells. These data imply that ROR2 may represent a novel target for melanoma therapy.

Show MeSH
Related in: MedlinePlus