Palbociclib has antitumour effects on Pten‐deficient endometrial neoplasias

• Published in: The Journal of pathology Vol. 242; no. 2; pp. 152 - 164
• Main Authors: Dosil, Maria Alba, Mirantes, Cristina, Eritja, Núria, Felip, Isidre, Navaridas, Raúl, Gatius, Sònia, Santacana, Maria, Colàs, Eva, Moiola, Cristian, Schoenenberger, Joan Antoni, Encinas, Mario, Garí, Eloi, Matias‐Guiu, Xavier, Dolcet, Xavier
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01-06-2017; Wiley Subscription Services, Inc
• Subjects: Animals; Antineoplastic Agents - pharmacology; Antineoplastic drugs; Antitumor agents; Breast cancer; Carcinogenesis; Carcinoma; CDK4/6; Cell cycle; Cell division; Cell proliferation; Cyclin D; Cyclin D1; Cyclin D1 - antagonists & inhibitors; Cyclin D1 - genetics; Cyclin D1 - metabolism; Cyclin-dependent kinase 4; Cyclin-Dependent Kinase 4 - antagonists & inhibitors; Cyclin-Dependent Kinase 4 - genetics; Cyclin-Dependent Kinase 6 - antagonists & inhibitors; Cyclin-Dependent Kinase 6 - genetics; Disease Models, Animal; Endometrial cancer; endometrial carcinoma; Endometrial Neoplasms - drug therapy; Endometrial Neoplasms - genetics; Endometrial Neoplasms - pathology; Endometrium; Female; Humans; Inhibition; Metastases; Mice; Mice, Knockout; palbociclib; Piperazines - pharmacology; Protein Kinase Inhibitors - pharmacology; Proteins; PTEN; PTEN Phosphohydrolase - genetics; PTEN protein; Pyridines - pharmacology; Rodents; Tamoxifen; Tamoxifen - adverse effects; Transplantation, Heterologous; Tumor cell lines; Tumors; Uterine cancer; Xenografts; United Kingdom > UK; Ireland; PTEN; cyclin D1; endometrial carcinoma; CDK4/6; palbociclib
• ISSN: 0022-3417; 1096-9896
• DOI: 10.1002/path.4896

PTEN is one of the most frequently mutated genes in human cancers. The frequency of PTEN alterations is particularly high in endometrial carcinomas. Loss of PTEN leads to dysregulation of cell division, and promotes the accumulation of cell cycle complexes such as cyclin D1–CDK4/6, which is an important feature of the tumour phenotype. Cell cycle proteins have been presented as key targets in the treatment of the pathogenesis of cancer, and several CDK inhibitors have been developed as a strategy to generate new anticancer drugs. Palbociclib (PD‐332991) specifically inhibits CDK4/6, and it has been approved for use in metastatic breast cancer in combination with letrazole. Here, we used a tamoxifen‐inducible Pten knockout mouse model to assess the antitumour effects of cyclin D1 knockout and CDK4/6 inhibition by palbociclib on endometrial tumours. Interestingly, both cyclin D1 deficiency and palbociclib treatment triggered shrinkage of endometrial neoplasias. In addition, palbociclib treatment significantly increased the survival of Pten‐deficient mice, and, as expected, had a general effect in reducing tumour cell proliferation. To further analyse the effects of palbociclib on endometrial carcinoma, we established subcutaneous tumours with human endometrial cancer cell lines and primary endometrial cancer xenografts, which allowed us to provide more translational and predictive data. To date, this is the first preclinical study evaluating the response to CDK4/6 inhibition in endometrial malignancies driven by PTEN deficiency, and it reveals an important role of cyclin D–CDK4/6 activity in their development. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.