PTEN and DNA-PK determine sensitivity and recovery in response to WEE1 inhibition in human breast cancer

Abstract

<jats:p>Inhibition of WEE1 kinase by AZD1775 has shown promising results in clinical cancer trials, but markers predicting AZD1775 response are lacking. Here we analysed AZD1775 response in a panel of human breast cancer (BC) cell lines by global proteome/transcriptome profiling and identified two groups of basal-like BC (BLBCs): ‘PTEN low’ BLBCs were highly sensitive to AZD1775 and failed to recover following removal of AZD1775, while ‘PTEN high’ BLBCs recovered. AZD1775 induced phosphorylation of DNA-PK, protecting cells from replication-associated DNA damage and promoting cellular recovery. Deletion of DNA-PK or PTEN, or inhibition of DNA-PK sensitized recovering BLBCs to AZD1775 by abrogating replication arrest, allowing replication despite DNA damage. This was linked to reduced CHK1 activation, increased cyclin E levels and apoptosis. In conclusion, we identified PTEN and DNA-PK as essential regulators of replication checkpoint arrest in response to AZD1775 and defined PTEN as a promising biomarker for efficient WEE1 cancer therapy.</jats:p>

Ex vivo analysis of DNA repair targeting in extreme rare cutaneous apocrine sweat gland carcinoma

“…To assess dependency of the patient derived cells on different DNA repair pathways and to identify DNA repair enzymes possibly contributing to the sensitivity or resistance of the cells to BETi, a siRNA screen with a custom library covering 300 genes with a known or suspected role in the DDR [ 18 ] was undertaken. Following successful validation of the ability to transfect the cells using a lipid transfection agent (Supplementary Figure 1), two replicate screens were initiated with the patient derived cancer cells remaining from the initial ex vivo drug screening.…”

“…The phenotypic image-based siRNA screens were performed in 384-well format as previously described [ 18 ]. Briefly, a custom collected DNA damage siRNA library consisting of three individual siRNAs for 300 DNA repair genes (ON-TARGET plus siRNA, Dharmacon) was pre-printed into 384 wells and complexed with 0.06 μL of siLentFect (Bio-Rad) lipid transfection agent for transfection (Supplementary Figure 1).…”

“…Of these, two different BET-bromodomain inhibitors; JQ1 and ODM-207 were the most potent drugs with a known DNA repair targeting mechanisms. To assess DNA repair pathways essential for the tumor cells and contributing to sensitivity/resistance of the tumor cells to BETi, we use ex vivo functional RNAi screening [ 18 ] to discover biological insights on the different DNA repair pathways with the PALB2 deficient cells. To extend the analysis beyond the patient derived cells, we go on to assess with publicly available drug screening data the correlation between efficacy of PARP inhibitors Olaparib, Talazoparib and BETi on 800 model cell lines divided to unaltered or PALB2 altered cell lines.…”

Targeting WEE1 Inhibits Growth of Breast Cancer Cells That Are Resistant to Endocrine Therapy and CDK4/6 Inhibitors

“…Particularly in breast cancer, Murrow et al used a RNAi screen of the human tyrosine kinome, to identify WEE1 as a potential therapeutic target in triple-negative breast cancer cells that lack ER, progesterone receptor [PR] or HER2 (27). In recent years, a number of preclinical studies have focused on understanding the functionality of WEE1 in breast cancer cells, particularly those with defective cell cycle regulation (28)(29)(30).…”

Pharmacological Inhibition of WEE1 Potentiates the Antitumoral Effect of the dl922-947 Oncolytic Virus in Malignant Mesothelioma Cell Lines

“…Based on this rationale, many studies focused on the effects of WEE1 inhibition in combination with DNA damaging agents in tumors bearing TP53 mutations. However, other mechanisms, such as DDR aberrations, nucleotide starvation, replicative stress, and, as more recently found, loss of the ATRX chromatin remodeler gene [ 36 ] and low phosphatase and tensin homolog (PTEN) expression [ 37 ], contribute to sensitize cancer cells to WEE1 inhibition, which, thus, proved monotherapy activity even in TP53 -wild-type cancer cells [ 29 , 30 , 38 ]. Moreover, WEE1 inhibition showed efficacy also in combination with inhibitors of other DDR factors, such as PARP [ 39 , 40 , 41 , 42 ], CHK1 [ 29 , 43 , 44 , 45 , 46 , 47 ], and ataxia telangiectasia and Rad3 related (ATR) kinase [ 48 , 49 , 50 ], and also when combined with different anticancer targeted agents [ 29 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ] and immunotherapeutic approaches [ 29 , 62 , 63 , 64 ].…”