Abstract 5729
Background
Inactivation of tumor suppressor p53 is a common event in tumor progression. In almost 50% of cases p53 inactivation is caused by mutations that primarily affect DNA-binding domain. Oncogenic missense mutation Y220C is the ninth most common for p53 and is annually observed in ∼100,000 new diagnosed cancer cases worldwide. Presence of this mutation disturbs tertiary structure of the p53 DNA-binding domain that further leads to destabilization of the whole protein, its partial denaturation and loss of transcriptional activity. In some cases, p53 mutations result in more aggressive cancer cells and alter drug sensitivity.
Methods
We employ CRISPR-Cas9 gene editing technology to generate p53 knock-out and Y220C mutant MCF-7 cell lines. Quantitative analysis of alterations in intracellular protein levels were performed by immunoblotting, analysis of p53-dependent gene expression by quantitative real-time reverse transcription PCR; cell proliferation and chemotherapy cytotoxicity by MTS test. Statistical analysis was performed using ANOVA and Holm-Sidak method for multiple comparison, p ≤ 0.05 was considered to be statistically significant.
Results
We have confirmed that p53 mutation Y220C leads to p53 inactivation. Proliferation rate of p53 knockout and mutant MCF-7 cell lines was 15% higher than wild type. We have shown statistically significant decrease in topotecan cytotoxicity towards knockout and mutant cells compared to wild-type – 14% and 26%, respectively.
Conclusions
Decline of topotecan cytotoxicity in mutant and knockout cells can be explained by topotecan-mediated induction of p53 that leads to higher levels of cell death in wild-type MCF-7. References Bulatov, E., Zagidullin, A., Valiullina, A., Sayarova, R., Rizvanov, A. (2018). Small molecule modulators of RING-type E3 ligases: MDM and Cullin families as targets. Frontiers in pharmacology, 9, 450.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Albert Rizvanov.
Funding
Grant of the President of the Russian Federation (MK-4253.2018.4).
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3157 - Efficacy and safety of anlotinib in advanced leiomyosarcoma: Subgroup analysis of a phase IIB trial (ALTER0203)
Presenter: Yihebali Chi
Session: Poster Display session 1
Resources:
Abstract
3710 - The effect of treatment line on the efficacy of Anlotinib hydrochloride in advanced alveolar soft part sarcoma patients
Presenter: Zhiwei Fang
Session: Poster Display session 1
Resources:
Abstract
3184 - Prior exposure to pazopanib (PAZ) did not minor efficacy of regorafenib (REG) in non-adipocytic soft tissue sarcoma patients (pts)
Presenter: Nicolas Penel
Session: Poster Display session 1
Resources:
Abstract
798 - Pexidartinib (Pex) for locally advanced tenosynovial giant cell tumor (TGCT): characterization of hepatic adverse reactions (ARs)
Presenter: Sebastian Bauer
Session: Poster Display session 1
Resources:
Abstract
6117 - VEGFR2 and ITGA polymorphisms as novel pan-sarcoma biomarkers for sensitivity prediction as well as toxicity prevention anti-angiogenesis therapy in pediatric and young adult
Presenter: Qiyuan Bao
Session: Poster Display session 1
Resources:
Abstract
5450 - Reversion of resistance to mTOR inhibitors with the addition of exemestane in patients with malignant PEComa.
Presenter: Roberta Sanfilippo
Session: Poster Display session 1
Resources:
Abstract
4279 - Efficacy and Safety of VEGFR2 Inhibitor Apatinib combined with chemotherapy for Sarcoma in Stage IV
Presenter: Zhiwu Ren
Session: Poster Display session 1
Resources:
Abstract
5929 - Outcomes of metastatic soft tissue sarcoma treated with Pazopanib from dedicated medical oncology sarcoma clinic: A holistic care approach from a developing country
Presenter: Akhil Kapoor
Session: Poster Display session 1
Resources:
Abstract
2469 - Inhibition of mTOR signaling enhances Trabectedin activity in Soft Tissue Sarcoma
Presenter: David Moura
Session: Poster Display session 1
Resources:
Abstract
4210 - Efficacy and safety of apatinib for advanced gastrointestinal stromal tumors after failure of imatinib and sunitinib: An open-label, multicenter, single-arm, phase II trial
Presenter: Zhaolun Cai
Session: Poster Display session 1
Resources:
Abstract