Dataset Information

Metastasis suppressor function of NM23-H1 requires its 3'-5' exonuclease activity.

ABSTRACT: The metastasis suppressor NM23-H1 possesses 3 enzymatic activities in vitro, a nucleoside diphosphate kinase (NDPK), a protein histidine kinase and a more recently characterized 3'-5' exonuclease. Although the histidine kinase has been implicated in suppression of motility in breast carcinoma cell lines, potential relevance of the NDPK and 3'-5' exonuclease to metastasis suppressor function has not been addressed in detail. To this end, site-directed mutagenesis and biochemical analyses of bacterially expressed mutant NM23-H1 proteins have identified mutations that disrupt the 3'-5' exonuclease alone (Glu(5) to Ala, or E(5) A), the NDPK and histidine kinase activities tandemly (Y(52) A, H(118) F) or all 3 activities simultaneously (K(12) Q). Although forced expression of NM23-H1 potently suppressed spontaneous lung metastasis of subcutaneous tumor explants derived from the human melanoma cell line 1205LU, no significant metastasis suppressor activity was obtained with the exonuclease-deficient variants E(5) A and K(12) Q. The H(118) F mutant, which lacked both the NDPK and histidine kinase while retaining the 3'-5' exonuclease, also exhibited compromised suppressor activity. In contrast, each mutant retained the ability to suppress motility and invasive characteristics of 1205LU cells in culture, indicating that the NM23-H1 molecule possesses an additional activity(s) mediating these suppressor functions. These studies provide the first demonstration that the 3'-5' exonuclease activity of NM23-H1 is necessary for metastasis suppressor function and further indicate cooperativity of the 3 enzymatic activities of the molecule on suppression of the metastatic process.

SUBMITTER: Zhang Q

PROVIDER: S-EPMC2946830 | biostudies-literature | 2011 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Metastasis suppressor function of NM23-H1 requires its 3'-5' exonuclease activity.

Zhang Qingbei Q McCorkle Joseph R JR Novak Marian M Yang Mengmeng M Kaetzel David M DM

International journal of cancer 20110101 1

The metastasis suppressor NM23-H1 possesses 3 enzymatic activities in vitro, a nucleoside diphosphate kinase (NDPK), a protein histidine kinase and a more recently characterized 3'-5' exonuclease. Although the histidine kinase has been implicated in suppression of motility in breast carcinoma cell lines, potential relevance of the NDPK and 3'-5' exonuclease to metastasis suppressor function has not been addressed in detail. To this end, site-directed mutagenesis and biochemical analyses of bacte ...[more]

PMID: 20209495

Similar Datasets

Project description:BackgroundNm23-H1 gene has been found to be an inhibitor of tumor metastasis in lung cancer. MicroRNAs (miRNAs) play key roles in tumor metastasis through multiple signaling pathways. This study explored whether the nm23-H1 gene could inhibit invasion and metastasis of lung cancer cells by regulating miRNA-660-5p targets.MethodsQuantitative real-time PCR (qRT-PCR) and western blots were used to measure the expression of nm23-H1 and miR-660-5p of various human lung cancer cell lines. Cell counting kit-8 (CCK-8), wound-healing and transwell assay were carried out to assess cell proliferation, migration and invasion of each cell line. Xenograft were applied to determine in vivo effects of miR-660-5p among nude mice. Luciferase assay and western blot were performed to determine the target gene of miR-660-5p.ResultsWe found that high expression of nm23-H1 correlated with decreased miRNA-660-5p expression. Inhibiting miR-660-5p suppressed lung cancer cells progression significantly in vitro, whereas overexpression of miR-660-5p facilitated tumor growth and bone metastasis in vivo. In addition, as the potential target gene of miR-660-5p, SMARCA5 overexpression in vitro suppressed tumor progression and osteolytic metastasis associated RANKL signaling, which is congruent with the effect of nm23-H1 on the lung cancer cells.ConclusionNm23-H1 inhibits tumor progression and bone-specific metastasis of lung cancer by regulating miR-660-5p/SMARCA5/RANKL axis, which indicates the related genes may serve as potential targets for the treatment of human lung cancer.Key pointsSignificant findings of the study High expression of nm23-H1 correlated with decreased miRNA-660-5p expression. Further, downregulation of miR-660-5p significantly suppressed the tumor progression and bone-specific metastasis of lung cancer cells. What this study adds This is the first study to show an inverse association between nm23-H1 and miR-660-5p, and confirm that nm23-H1 inhibits tumor progression and bone-specific metastasis of lung cancer by regulating miR-660-5p/SMARCA5/RANKL axis.

Dataset Information

Metastasis suppressor function of NM23-H1 requires its 3'-5' exonuclease activity.

Publications

Metastasis suppressor function of NM23-H1 requires its 3'-5' exonuclease activity.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets