Published in:
01-10-2010 | Translational Research and Biomarkers
Higher Expression of the Heterogeneous Nuclear Ribonucleoprotein K in Melanoma
Authors:
Fushi Wen, PhD, Alex Shen, BS, Reneé Shanas, BS, Achyut Bhattacharyya, MD, Fangru Lian, MD, Galen Hostetter, MD, Jiaqi Shi, MD, PhD
Published in:
Annals of Surgical Oncology
|
Issue 10/2010
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Abstract
Background
The heterogeneous nuclear ribonucleoprotein (hnRNP) K is an essential RNA and DNA binding protein involved in gene expression and signal transduction. The role of hnRNP K in cancer is relatively understudied. However, several cellular functions strongly indicate that hnRNP K is involved in tumorigenesis. Oncogenes c-Src, c-myc, and eIF4E are regulated by hnRNP K. We have shown an increased cytoplasmic hnRNP K in pancreatic cancer. In the present study, we investigated the altered expression of hnRNP K protein and its correlation with p-ERK in melanoma using human melanoma cell lines and tissue microarray.
Materials and Methods
The protein levels of hnRNP K and p-ERK in 8 human melanoma cell lines and a melanoma progression tissue microarray containing 80 melanoma, 23 dysplastic nevi, and 14 benign nevi specimens were analyzed using Western blot and immunohistochemistry analysis. hnRNP K was knocked down by siRNA, and its effect on melanoma cells was assessed.
Results
We showed a higher hnRNP K protein level in both melanoma cell lines and melanoma tissue specimens, which correlated with a higher c-myc expression. An increase in the cytoplasmic hnRNP K and eIF4E protein levels in melanoma cells is also seen. p-ERK level was also higher in dysplastic nevi and melanoma tissues, but did not correlate with hnRNP K protein level. We then demonstrated that knocking down of hnRNP K by siRNA inhibited melanoma cell growth and colony formation, as well as c-myc expression.
Conclusions
hnRNP K expression correlated with melanoma and may play a role in melanoma tumorigenesis.