Cancer Res Treat.  2009 Jun;41(2):87-92.

Cytoplasmic Expression of HuR is Related to Cyclooxygenase-2 Expression in Colon Cancer

• Lim SJ
• Lee SH
• Joo SH
• Song JY
• Choi SI

Abstract

PURPOSE
HuR, human family embryonic-lethal abnormal vision-like protein, can bind to mRNA and stabilizes the nucleic acid in the cytoplasm, resulting in more efficient translation. HuR is predominantly present in the nucleus and shuttles between the nucleus and cytoplasm. HuR stabilizes cyclooxygenase-2 (Cox-2) mRNA in several cancers, including breast, stomach, lung and brain cancer. MATERIALS AND METHODS: We investigated the expression and cellular location of HuR, as well as evaluated Cox-2 expression in 79 colorectal cancer patients with the use of immunohistochemical methods. The biological implications of HuR localization and Cox-2 expression in colorectal carcinoma were evaluated. RESULTS: Nuclear HuR expression was observed in 59 (74.7%) tumors and cytoplasmic HuR expression was seen in 25 (31.6%) tumors. Cox-2 immunoreactivity was noted in 42 (53%) tumors. The expression of cytoplasmic HuR was significantly associated with Cox-2 expression (p=0.004). Cytoplasmic expression of HuR showed a correlation with lymphatic invasion (p=0.025) and the presence of a lymph node metastasis (p=0.027). The presence of nuclear HuR showed no correlation with Cox-2 expression or any other of the clinicopathological parameters that were examined. CONCLUSION: These results suggest that cytoplasmic translocation of HuR is associated with Cox-2 expression for some colorectal carcinomas.

Keyword

Colorectal neoplasms; HuR; Cyclooxygenase-2

MeSH Terms

Brain Neoplasms
Breast
Colon
Colonic Neoplasms
Colorectal Neoplasms
Cyclooxygenase 2
Cytoplasm
Humans
Lung
Lymph Nodes
Neoplasm Metastasis
RNA, Messenger
Stomach
Cyclooxygenase 2
RNA, Messenger

Figure

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  Fig. 1 Strong nuclear (A,×400) and cytoplasmic expression (B,×400) of HuR were noted in a colorectal cancer specimen, but the normal colonic mucosa showed diffuse nuclear staining in the crypt glands (C,×200).

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  Fig. 2 Diffuse strong cytoplasmic expression of Cox-2 for an adenocarcinoma in the colon (A,×200) was seen, and no staining was seen in the normal mucosa (B,×200).

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