CCBIO Seminar: Klas Wiman
Welcome to CCBIO Seminar with speaker Klas Wiman from the Department of Oncology-Pathology, Karolinska Institutet, Sweden.
Apart from the interesting talks, the CCBIO seminars are a good way to meet CCBIO members and associates. Please feel free to inform others about this seminar as all are welcome both to the lecture and the pizza get-together afterwards.
Invited speaker: Klas Wiman, Karolinska Institutet, Dept. of Oncology-Pathology, Cancer Center Karolinska (CCK), Stockholm, Sweden
Time: March 16th 2017 at 14:30, Auditorium 4, BBB
Host: Bjørn Tore Gjertsen
Title: "Targeting missense and nonsense mutant p53 in cancer – from molecular biology to the clinic"
The TP53 tumor suppressor gene is frequently mutated in human tumors. The p53 protein responds to cellular stress and regulates cell cycle progression and cell death through transactivation of downstream target genes, e.g. p21 and Puma. p53 can also regulate processes such as metabolism, differentiation and fertility. A large fraction of human tumors carry missense mutant p53. We have earlier identified the mutant p53-targeting compound APR-246 (PRIMA-1Met). APR-246 is converted to MQ, a Michael acceptor that binds to cysteines in the p53 core domain. APR-246 shows striking synergy with chemotherapeutic drugs, e.g. cisplatin and doxorubicin. APR-246 can also target components of the cellular redox system, including thioredoxin reductase (TrxR1) and glutathione (GSH), which probably contributes to the anti-tumor effect. APR-246 has been tested in a first-in-man phase I clinical trial in patients with hematological malignancies or prostate cancer. Clinical effects were observed. A phase II proof-of-concept clinical study in high-grade serous (HGS) ovarian cancer is currently conducted by Aprea Therapeutics AB. A subset of TP53 mutations are nonsense mutations that give rise to truncated and unstable p53 protein. Aminoglycoside antibiotics at high concentrations have been shown to induce translational readthrough of nonsense mutant TP53 and expression of full length p53. Tumor suppressor genes like APC, PTEN, RB1 and BRCA1 carry nonsense mutations at even higher frequency than TP53. We are now screening for novel and less toxic compounds with higher readthrough-inducing potency. Pharmacological induction of translational readthrough of premature stop codons in tumor suppressor genes is a promising strategy for efficient treatment of cancer in the future.