Abstract
Background:Although the founding members of the INhibitor of Growth (ING) family of histone mark readers, ING1 and ING2, were defined as tumour suppressors in animal models, the role of other ING proteins in cellular proliferation and cancer progression is unclear.Methods:We transduced ex vivo benign prostate hyperplasia tissues with inducible lentiviral particles to express ING proteins. Proliferation was assessed by H3S10phos immunohistochemistry (IHC). The expression of ING3 was assessed by IHC on a human prostate cancer tissue microarray (TMA). Gene expression was measured by DNA microarray and validated by real-time qPCR.Results:We found that ING3 stimulates cellular proliferation in ex vivo tissues, suggesting that ING3 could be oncogenic. Indeed, ING3 overexpression transformed normal human dermal fibroblasts. We observed elevated levels of ING3 in prostate cancer samples, which correlated with poorer patient survival. Consistent with an oncogenic role, gene-silencing experiments revealed that ING3 is required for the proliferation of breast, ovarian, and prostate cancer cells. Finally, ING3 controls the expression of an intricate network of cell cycle genes by associating with chromatin modifiers and the H3K4me3 mark at transcriptional start sites.Conclusions:Our investigations create a shift in the prevailing view that ING proteins are tumour suppressors and redefine ING3 as an oncoprotein.
Highlights
The founding members of the INhibitor of Growth (ING) family of histone mark readers, ING1 and ING2, were defined as tumour suppressors in animal models, the role of other ING proteins in cellular proliferation and cancer progression is unclear
We found that ING3 stimulates cellular proliferation in ex vivo tissues, suggesting that ING3 could be oncogenic
Our investigations create a shift in the prevailing view that ING proteins are tumour suppressors and redefine ING3 as an oncoprotein
Summary
We transduced ex vivo benign prostate hyperplasia tissues with inducible lentiviral particles to express ING proteins. The expression of ING3 was assessed by IHC on a human prostate cancer tissue microarray (TMA). The cDNA of human ING3 was cloned by PCR from total RNA extracted from the MCF7 cell line using forward 50-GGCCAGATCTTTGTACCTAGAAGACTATCTGGA-30 and reverse 50-AGGACTCGAGTTATTTGTGTCTGCTGCCTCT-30 primers, inserted in pCMV-3Tag-1A (Stratagene, Agilent, CA, USA) in frame with the 3xFLAG tag. The 3xFLAG-tagged ING3 cDNA was inserted in the pLVX Lenti-X Tet-One inducible expression system (Clontech, Takara, France) using the In-Fusion HD enzyme (Clontech). The anti-a-tubulin and a-FLAG antibodies, as well as a-FLAG M2-agarose were purchased from Sigma (Gillingham, UK). The HRP-conjugated a-GST (ab3416), a-H3 (ab1791), aH3K4me (ab8580), and a-TIP49A (ab133513) antibodies were purchased from Abcam (Cambridge, UK)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
