Ppp1r14b, protein phosphatase 1 regulatory subunit 14B, is a member of the protein phosphatase 1 regulatory subunits. It can inhibit protein phosphatase 1 (PP1) and different PP1 holoenzymes, which are important in regulating cell growth, the cell cycle, and apoptosis [2].

Gain-and loss-of-function assays in multiple cancer cell lines have demonstrated significant roles of Ppp1r14b. In triple-negative breast cancer, knockdown of Ppp1r14b inhibited cell proliferation, colony formation, migration, invasion, and increased sensitivity to paclitaxel both in vitro and in vivo. Mechanistically, it maintains phosphorylation and stability of oncoprotein stathmin 1 (STMN1), which is crucial for cancer progression and paclitaxel resistance [1]. Similar tumor-promoting effects were seen in other cancers. For example, in hepatocellular carcinoma, knockdown of Ppp1r14b significantly inhibited cell survival and tumorigenic ability, while overexpression had opposite effects. It regulated the stability and phosphorylation of RPS6KA1 and activated the AKT/NF-κB pathway [3]. In cervical and endometrial cancers, silencing Ppp1r14b constrained cell proliferation and promoted cell death by suppressing the activation of the Akt pathway [4].

In conclusion, Ppp1r14b plays a tumor-promoting role in multiple cancers, including triple-negative breast cancer, hepatocellular carcinoma, cervical and endometrial cancers. Through loss-of-function experiments in cell lines, its key role in promoting cancer cell proliferation, migration, invasion and drug resistance has been revealed. Understanding the function of Ppp1r14b provides potential therapeutic targets for these cancers.