The binding between NPM and H2B proteins signals for the diabetes‐associated centrosome amplification.

Diabetes not only increases the risk for cancer but also promotes cancer metastasis. Centrosome amplification (CA) is sufficient to initiate tumorigenesis and can enhance the invasion potential of cancer cells. We have reported that diabetes can induce CA, with diabetic pathophysiological factors as the triggers, which involves the signaling of nucleophosmin (NPM). Thus, CA can serve as a candidate biological link between diabetes and cancer. In the present study, we attempted to identify the NPM binding partners and investigated whether the binding between NPM and its partner mediated the CA. We confirmed that high glucose, insulin, and palmitic acid cancer could elicit CA in the HCT16 colon cancer cells and found that the experimental treatment increased the binding between NPM and H2B, but not between p‐NPM and H2B. The molecular docking analysis supported the fact that NPM and H2B could bind to each other through various amino acid residues. The treatment also increased the colocalization of NPM and H2B in the cytosol. Importantly, disruption of the NPM1–H2B complex by individual knockdown of the protein level of NPM or H2B led to the inhibition of the treatment‐evoked CA. In conclusion, our results suggest that the binding between NPM and H2B proteins signals for the CA by high glucose, insulin, and palmitic acid. Significance statement: Diabetes is increasingly recognized as a significant risk factor for cancer initiation and progression. Amplification of the centrosome is sufficient to induce carcinogenesis and can increase cancer cell invasion potential. Previous research has demonstrated that diabetic pathophysiological factors can cause centrosome amplification (CA) in both noncancerous and malignant colon cells. As a result, we suspect CA is a molecular relationship between diabetes and cancer. However, the mechanism behind this association between diabetes and cancer remains unknown. In the current study, we discovered that the interaction between nucleophosmin (NPM) and H2B caused diabetes‐associated CA, providing a target for decreasing diabetes‐associated CA and allowing us to investigate its functions in carcinogenesis and cancer cell metastasis. Our findings also show that H2B has a biological purpose other than nucleosome construction and gene transcription control in the nucleus, which is signaling for CA in the cytoplasm. Furthermore, the identification of the binding between NPM and H2B, but not phosphorylated NPM and H2B, as a signal for CA adds a new piece of information in the regulation of centrosome homeostasis, which could lead to a new method of cancer treatment by targeting CA. [ABSTRACT FROM AUTHOR]