American Association for Cancer Research
15357163mct170040-sup-177388_2_supp_4084154_mr4sx4.pptx (1.28 MB)

Supplementary Figures 1-6 from CDK4/6 Inhibitors Sensitize Rb-positive Sarcoma Cells to Wee1 Kinase Inhibition through Reversible Cell-Cycle Arrest

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posted on 2023-04-03, 15:47 authored by Ashleigh M. Francis, Angela Alexander, Yanna Liu, Smruthi Vijayaraghavan, Kwang Hui Low, Dong Yang, Tuyen Bui, Neeta Somaiah, Vinod Ravi, Khandan Keyomarsi, Kelly K. Hunt

Supplemental Figure 1: Schematic of HTSA and dose response curves of doxorubicin and AZD-1775 in different cell lines. Supplemental Figure 2: Cell cycle analysis following palbociclib treatment. Supplemental Figure 3: Schematic of combination index determination and combination index values of different drug combinations. Supplemental Figure 4: Combination treatment efficacy in SK-LMS1 Rb knockdown cells. Supplemental Figure 5: Western blot for apoptosis markers for SK-LMS1 cells treated with palbociclib. Supplemental Figure 6: Mouse weights over course of vehicle, single drugs and combination treatments.


Department of Defense Breast Cancer Research Program Postdoctoral Fellowship

T32 Fellowship


Sarcoma Foundation of America

Alan B. Slifka and National Leiomyosarcoma Research Foundations

John Wayne Cancer Foundation

MD Anderson's Cancer Center Support



Research into the biology of soft tissue sarcomas has uncovered very few effective treatment strategies that improve upon the current standard of care which usually involves surgery, radiation, and chemotherapy. Many patients with large (>5 cm), high-grade sarcomas develop recurrence, and at that point have limited treatment options available. One challenge is the heterogeneity of genetic drivers of sarcomas, and many of these are not validated targets. Even when such genes are tractable targets, the rarity of each subtype of sarcoma makes advances in research slow. Here we describe the development of a synergistic combination treatment strategy that may be applicable in both soft tissue sarcomas as well as sarcomas of bone that takes advantage of targeting the cell cycle. We show that Rb-positive cell lines treated with the CDK4/6 inhibitor palbociclib reversibly arrest in the G1 phase of the cell cycle, and upon drug removal cells progress through the cell cycle as expected within 6–24 hours. Using a long-term high-throughput assay that allows us to examine drugs in different sequences or concurrently, we found that palbociclib-induced cell-cycle arrest poises Rb-positive sarcoma cells (SK-LMS1 and HT-1080) to be more sensitive to agents that work preferentially in S–G2 phase such as doxorubicin and Wee1 kinase inhibitors (AZD1775). The synergy between palbociclib and AZD1775 was also validated in vivo using SK-LMS1 xenografts as well as Rb-positive patient-derived xenografts (PDX) developed from leiomyosarcoma patients. This work provides the necessary preclinical data in support of a clinical trial utilizing this treatment strategy. Mol Cancer Ther; 16(9); 1751–64. ©2017 AACR.