Biology subjects

Nehme, J.

Publications and source records attributed to Nehme, J..

2 recordsLinked to original sources

bioRxiv2026

Reproducible in vivo applications of the p16-3MR model in senescence research

The p16-3MR mouse model has been widely used to visualize and conditionally eliminate p16-expressing senescent cells in vivo and has been applied across diverse biological contexts, including tissue repair, fibrosis, cancer, therapy response, and aging. Despite the development of multiple senescence reporter and ablation systems, p16-3MR stands out for its broad and sustained adoption across independent laboratories. Here, we review the extensive published literature supporting the reproducibility and utility of the p16-3MR system and present new validation data across acute and chronic senescence-inducing conditions. We demonstrate reproducible induction of p16-associated bioluminescence during wound healing, chemotherapy, and aging, as well as partial but consistent reduction following ganciclovir treatment. We further delineate the strengths and limitations of the individual components of the 3MR construct, including HSV-thymidine kinase-mediated clearance, Renilla luciferase- based bioluminescence, and monomeric red fluorescent protein, and discuss how factors such as cell abundance, tissue context, pigmentation, and substrate chemistry influence detection sensitivity. Together, these data confirm that the p16-3MR model is a functional and versatile tool for studying senescent cells in vivo when used with appropriate experimental design and interpretation, and they provide support for its continued application alongside emerging senescence models.

cell biology↗

bioRxiv2024

CDK4/6 inhibitors promote senescence-associated lysosomal alterations and enhance sensitivity to lysosomotropic agents in breast cancer

Breast cancer is a leading cause of mortality worldwide. Pharmacological inhibitors of Cyclin- Dependent Kinases (CDK) 4 and 6 (CDK4/6i) inhibit breast cancer growth by inducing a senescent-like state. However, the long-term treatment efficacy remains hindered by the development of drug resistance. Clearance of senescent-like cancer cells may extend the durability of treatment. In this study, we showed that CDK4/6i-treated breast cancer cells exhibit various senescence-associated phenotypes, but remain insensitive to common senolytic compounds. By searching for novel vulnerabilities, we identified a significantly increased lysosomal mass and altered lysosomal structure across various breast cancer cell types upon exposure to CDK4/6i in preclinical systems and clinical specimens. We demonstrated that these lysosomal alterations render breast cancer cells sensitive to lysosomotropic agents, such as L- leucyl-L-leucine methyl ester (LLOMe) and salinomycin. Importantly, sequential treatment with CDK4/6i/lysosomotropic agents effectively reduced the growth of both Hormone Receptor- positive (HR+) and triple-negative breast cancer (TNBC) cells in vivo. This sequential therapeutic strategy offers a promising approach to eliminate CDK4/6i-induced senescent(-like) cells, potentially reducing tumor recurrence and enhancing the overall efficacy of breast cancer therapy.

cancer biology↗