MPP7, also known as MAGUK p55 scaffold protein 7, is a cell polarity controller that belongs to the membrane palmitoylated protein subfamily. It is involved in cell-cell contacts and adhesion, and is crucial for the establishment of epithelial cell polarity. MPP7 has been implicated in multiple signaling pathways, such as the EGFR/AKT, Wnt/β-catenin, and Rap1 signaling pathways, which are associated with various biological processes including cell migration, invasion, and autophagy [1,3,6].

In cancer research, MPP7 has shown oncogenic potential. In breast cancer, its overexpression promotes cell migration and invasion via the EGFR/AKT signaling cascade, and high expression predicts poor survival [1]. In clear cell renal cell carcinoma, MPP7 expression is associated with pathological stage, histological grade, and survival status, and is linked to mitochondrial oxidative metabolism and immune cell infiltration [2]. In epithelial ovarian cancer, MPP7 is significantly overexpressed, and its knockdown inhibits cell proliferation, migration, and invasion, likely through mediating EMT via the Wnt/β-catenin pathway [3]. Similar oncogenic roles are also observed in esophageal cancer where MPP7 knockdown inhibits cell migration and invasion [5]. In pancreatic ductal adenocarcinoma, MPP7 is involved in the early stages of autophagy during autophagosome formation, by activating YAP1 to promote autophagy [4].

In summary, MPP7 plays essential roles in cell polarity, migration, invasion, and autophagy. Through functional studies including loss-of-function experiments in various cell models, its oncogenic role in multiple cancers has been revealed, suggesting it could be a potential biomarker and therapeutic target for these cancer types [1-6].

References:

1. Liao, Wanqin, Fan, Lixia, Li, Mingchan, Yang, Anping, Liu, Fang. 2021. MPP7 promotes the migration and invasion of breast cancer cells via EGFR/AKT signaling. In Cell biology international, 45, 948-956. doi:10.1002/cbin.11538. https://pubmed.ncbi.nlm.nih.gov/33377561/

2. Cheng, Xiaowei, Sun, Ding, Li, Hao, Yuan, Qing, Wang, Bin. . MPP7 is a potential prognostic marker and is associated with cancer metabolism and immune infiltration in clear cell renal cell carcinoma: a bioinformatics analysis based on the TCGA database. In Translational andrology and urology, 12, 642-658. doi:10.21037/tau-23-166. https://pubmed.ncbi.nlm.nih.gov/37181237/

3. Tao, Chunlin, Ni, Xiaoge. 2024. MPP7 mediates EMT via Wnt/β-catenin pathway to promote polarity changes in epithelial ovarian cancer cells. In Journal of Cancer, 15, 4490-4502. doi:10.7150/jca.96185. https://pubmed.ncbi.nlm.nih.gov/39006077/

4. New, Maria, Van Acker, Tim, Sakamaki, Jun-Ichi, Howell, Michael, Tooze, Sharon A. 2019. MDH1 and MPP7 Regulate Autophagy in Pancreatic Ductal Adenocarcinoma. In Cancer research, 79, 1884-1898. doi:10.1158/0008-5472.CAN-18-2553. https://pubmed.ncbi.nlm.nih.gov/30765601/

5. Li, Zhaodong, Tang, Yongyao, Cai, Jing, Wu, Shunlong, Song, Fangzhou. 2022. MPP7 as a Novel Biomarker of Esophageal Cancer: MPP7 Knockdown Inhibits Esophageal Cancer Cell Migration and Invasion. In Life (Basel, Switzerland), 12, . doi:10.3390/life12091381. https://pubmed.ncbi.nlm.nih.gov/36143417/

6. Xu, Xiaotong, Cheng, Weyland, Zhao, Shuai, Zhang, Yaodong, Ding, Cong. 2024. Pan-cancer analysis of the role of MPP7 in human tumors. In Heliyon, 10, e36148. doi:10.1016/j.heliyon.2024.e36148. https://pubmed.ncbi.nlm.nih.gov/39224268/