TY  - JOUR
A1  - Fischer, Thomas
A1  - Hartmann, Oliver
A1  - Reissland, Michaela
A1  - Prieto-Garcia, Cristian
A1  - Klann, Kevin
A1  - Pahor, Nikolett
A1  - Schülein-Völk, Christina
A1  - Baluapuri, Apoorva
A1  - Polat, Bülent
A1  - Abazari, Arya
A1  - Gerhard-Hartmann, Elena
A1  - Kopp, Hans-Georg
A1  - Essmann, Frank
A1  - Rosenfeldt, Mathias
A1  - Münch, Christian
A1  - Flentje, Michael
A1  - Diefenbacher, Markus E.
T1  - PTEN mutant non-small cell lung cancer require ATM to suppress pro-apoptotic signalling and evade radiotherapy
JF  - Cell & Bioscience
N2  - Background
Despite advances in treatment of patients with non-small cell lung cancer, carriers of certain genetic alterations are prone to failure. One such factor frequently mutated, is the tumor suppressor PTEN. These tumors are supposed to be more resistant to radiation, chemo- and immunotherapy.

Results
We demonstrate that loss of PTEN led to altered expression of transcriptional programs which directly regulate therapy resistance, resulting in establishment of radiation resistance. While PTEN-deficient tumor cells were not dependent on DNA-PK for IR resistance nor activated ATR during IR, they showed a significant dependence for the DNA damage kinase ATM. Pharmacologic inhibition of ATM, via KU-60019 and AZD1390 at non-toxic doses, restored and even synergized with IR in PTEN-deficient human and murine NSCLC cells as well in a multicellular organotypic ex vivo tumor model.

Conclusion
PTEN tumors are addicted to ATM to detect and repair radiation induced DNA damage. This creates an exploitable bottleneck. At least in cellulo and ex vivo we show that low concentration of ATM inhibitor is able to synergise with IR to treat PTEN-deficient tumors in genetically well-defined IR resistant lung cancer models.
KW  - PTEN
KW  - ATM
KW  - IR
KW  - NSCLC
KW  - radiotherapy
KW  - cancer
KW  - DNA-PK
KW  - PI3K
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-299865
SN  - 2045-3701
VL  - 12
ER  - 
TY  - JOUR
A1  - Prieto-Garcia, Cristian
A1  - Hartmann, Oliver
A1  - Reissland, Michaela
A1  - Braun, Fabian
A1  - Bozkurt, Süleyman
A1  - Pahor, Nikolett
A1  - Fuss, Carmina
A1  - Schirbel, Andreas
A1  - Schülein-Völk, Christina
A1  - Buchberger, Alexander
A1  - Calzado Canale, Marco A.
A1  - Rosenfeldt, Mathias
A1  - Dikic, Ivan
A1  - Münch, Christian
A1  - Diefenbacher, Markus E.
T1  - USP28 enables oncogenic transformation of respiratory cells, and its inhibition potentiates molecular therapy targeting mutant EGFR, BRAF and PI3K
JF  - Molecular Oncology
N2  - Oncogenic transformation of lung epithelial cells is a multistep process, frequently starting with the inactivation of tumour suppressors and subsequent development of activating mutations in proto-oncogenes, such as members of the PI3K or MAPK families. Cells undergoing transformation have to adjust to changes, including altered metabolic requirements. This is achieved, in part, by modulating the protein abundance of transcription factors. Here, we report that the ubiquitin carboxyl-terminal hydrolase 28 (USP28) enables oncogenic reprogramming by regulating the protein abundance of proto-oncogenes such as c-JUN, c-MYC, NOTCH and ∆NP63 at early stages of malignant transformation. USP28 levels are increased in cancer compared with in normal cells due to a feed-forward loop, driven by increased amounts of oncogenic transcription factors such as c-MYC and c-JUN. Irrespective of oncogenic driver, interference with USP28 abundance or activity suppresses growth and survival of transformed lung cells. Furthermore, inhibition of USP28 via a small-molecule inhibitor resets the proteome of transformed cells towards a ‘premalignant’ state, and its inhibition synergizes with clinically established compounds used to target EGFR\(^{L858R}\)-, BRAF\(^{V600E}\)- or PI3K\(^{H1047R}\)-driven tumour cells. Targeting USP28 protein abundance at an early stage via inhibition of its activity is therefore a feasible strategy for the treatment of early-stage lung tumours, and the observed synergism with current standard-of-care inhibitors holds the potential for improved targeting of established tumours.
KW  - buparlisib
KW  - c-MYC
KW  - gefitinib
KW  - lung cancer
KW  - USP28
KW  - vemurafenib
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312777
VL  - 16
IS  - 17
ER  -