INPP4B suppresses prostate cancer cell invasion

Authors

Myles C. Hodgson, Herbert Wertheim College of Medicine, Florida International UniversityFollow
Elena I. Deryugina, The Scripps Research Institute
Egla Suarez, Herbert Wertheim College of Medicine, Florida International UniversityFollow
Sandra M. Lopez, Herbert Wertheim College of Medicine, Florida International UniversityFollow
Dong Lin, University of British Columbia
Hui Xue, University of British Columbia
Ivan P. Gorlov, Dartmouth College
Yuzhuo Wang, University of British Columbia; BC Cancer Agency
Irina U. Agoulnik, Herbert Wertheim College of Medicine, Florida International UniversityFollow

Date of this Version

9-25-2014

Document Type

Article

Abstract

Background

INPP4B and PTEN dual specificity phosphatases are frequently lost during progression of prostate cancer to metastatic disease. We and others have previously shown that loss of INPP4B expression correlates with poor prognosis in multiple malignancies and with metastatic spread in prostate cancer.

Results

We demonstrate that de novo expression of INPP4B in highly invasive human prostate carcinoma PC-3 cells suppresses their invasion both in vitro and in vivo. Using global gene expression analysis, we found that INPP4B regulates a number of genes associated with cell adhesion, the extracellular matrix, and the cytoskeleton. Importantly, de novo expressed INPP4B suppressed the proinflammatory chemokine IL-8 and induced PAK6. These genes were regulated in a reciprocal manner following downregulation of INPP4B in the independently derived INPP4B-positive LNCaP prostate cancer cell line. Inhibition of PI3K/Akt pathway, which is highly active in both PC-3 and LNCaP cells, did not reproduce INPP4B mediated suppression of IL-8 mRNA expression in either cell type. In contrast, inhibition of PKC signaling phenocopied INPP4B-mediated inhibitory effect on IL-8 in either prostate cancer cell line. In PC-3 cells, INPP4B overexpression caused a decline in the level of metastases associated BIRC5 protein, phosphorylation of PKC, and expression of the common PKC and IL-8 downstream target, COX-2. Reciprocally, COX-2 expression was increased in LNCaP cells following depletion of endogenous INPP4B.

Conclusion

Taken together, we discovered that INPP4B is a novel suppressor of oncogenic PKC signaling, further emphasizing the role of INPP4B in maintaining normal physiology of the prostate epithelium and suppressing metastatic potential of prostate tumors.

Comments

Originally published by BioMed Central Ltd.

Identifier

FIDC000546

Recommended Citation

Hodgson, Myles C.; Deryugina, Elena I.; Suarez, Egla; Lopez, Sandra M.; Lin, Dong; Xue, Hui; Gorlov, Ivan P.; Wang, Yuzhuo; and Agoulnik, Irina U., "INPP4B suppresses prostate cancer cell invasion" (2014). HWCOM Faculty Publications. 58.
https://digitalcommons.fiu.edu/com_facpub/58

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.