As treatment options for patients with incurable metastatic castration-resistant prostate cancer (mCRPC) are considerably limited, novel effective therapeutic options are needed. Checkpoint kinase 1 (CHK1) is a highly conserved protein kinase implicated in the DNA damage response (DDR) pathway that prevents the accumulation of DNA damage and controls regular genome duplication. CHK1 has been associated with prostate cancer (PCa) induction, progression, and lethality; hence, CHK1 inhibitors SCH900776 (also known as MK-8776) and the more effective SCH900776 analog MU380 may have clinical applications in the therapy of PCa. Synergistic induction of DNA damage with CHK1 inhibition represents a promising therapeutic approach that has been tested in many types of malignancies, but not in chemoresistant mCRPC. Here, we report that such therapeutic approach may be exploited using the synergistic action of the antimetabolite gemcitabine (GEM) and CHK1 inhibitors SCH900776 and MU380 in docetaxel-resistant (DR) mCRPC. Given the results, both CHK1 inhibitors significantly potentiated the sensitivity to GEM in a panel of chemo-naïve and matched DR PCa cell lines under 2D conditions. MU380 exhibited a stronger synergistic effect with GEM than clinical candidate SCH900776. MU380 alone or in combination with GEM significantly reduced spheroid size and increased apoptosis in all patient-derived xenograft 3D cultures, with a higher impact in DR models. Combined treatment induced premature mitosis from G1 phase resulting in the mitotic catastrophe as a prestage of apoptosis. Finally, treatment by MU380 alone, or in combination with GEM, significantly inhibited tumor growth of both PC339-DOC and PC346C-DOC xenograft models in mice. Taken together, our data suggest that metabolically robust and selective CHK1 inhibitor MU380 can bypass docetaxel resistance and improve the effectiveness of GEM in DR mCRPC models. This approach might allow for dose reduction of GEM and thereby minimize undesired toxicity and may represent a therapeutic option for patients with incurable DR mCRPC.

Department of Adaptive Biotechnologies Global Change Research Institute of the Czech Academy of Sciences Brno Czech Republic

Department of Biology Faculty of Medicine Masaryk University Brno Czech Republic

Department of Chemistry CZ Openscreen Faculty of Science Masaryk University Brno Czech Republic

Department of Cytokinetics Institute of Biophysics of the Czech Academy of Sciences Brno Czech Republic

Department of Experimental Biology Faculty of Science Masaryk University Brno Czech Republic

Department of Histology and Embryology Faculty of Medicine Masaryk University Brno Czech Republic

Department of Urology Erasmus MC Cancer Institute Erasmus University Medical Center Rotterdam The Netherlands

Department of Urology Experimental Urology Medical University of Innsbruck Austria

International Clinical Research Center Center for Biomolecular and Cellular Engineering St Anne's University Hospital in Brno Czech Republic

National Centre for Biomolecular Research Masaryk University Brno Czech Republic

School of Medicine Conway Institute of Biomolecular and Biomedical Research University College Dublin Ireland

Zobrazit více v PubMed

Siegel RL, Miller KD & Jemal A (2018) Cancer statistics, 2018. CA Cancer J Clin 68, 7–30. PubMed

Tannock IF, de Wit R, Berry WR, Horti J, Pluzanska A, Chi KN, Oudard S, Théodore C, James ND, Turesson I et al (2004) Docetaxel plus prednisone or mitoxantrone plus prednisone for advanced prostate cancer. N Engl J Med 351, 1502–1512. PubMed

Lombard AP, Liu C, Armstrong CM, Cucchiara V, Gu X, Lou W, Evans CP & Gao AC (2017) ABCB1 mediates cabazitaxel‐docetaxel cross‐resistance in advanced prostate cancer. Mol Cancer Ther 16, 2257–2266. PubMed PMC

Liu M, Zeng T, Zhang X, Liu C, Wu Z, Yao Luming, Xie Changchuan, Xia Hui, Lin Qi, Xie L et al (2018) ATR/Chk1 signaling induces autophagy through sumoylated RhoB‐mediated lysosomal translocation of TSC2 after DNA damage. Nat Commun 9, 4139. PubMed PMC

Robinson D, Van Allen EM, Wu YM, Schultz N, Lonigro RJ, Mosquera J‐M, Montgomery B, Taplin M‐E, Pritchard CC, Attard G et al (2015) Integrative clinical genomics of advanced prostate cancer. Cell 162, 454. PubMed

Leongamornlert D, Mahmud N, Tymrakiewicz M, Saunders E, Dadaev T, Castro E, Goh C, Govindasami K, Guy M, O'Brien L et al (2012) Germline BRCA1 mutations increase prostate cancer risk. Br J Cancer 106, 1697–701. PubMed PMC

Eastham JA, Stapleton AM, Gousse AE, Timme TL, Yang G, Slawin KM, Wheeler TM, Scardino PT & Thompson TC (1995) Association of p53 mutations with metastatic prostate cancer. Clin Cancer Res 1, 1111–1118. PubMed

Cimprich KA & Cortez D (2008) ATR: an essential regulator of genome integrity. Nat Rev Mol Cell Biol 9, 616–627. PubMed PMC

Bartek J & Lukas J (2007) DNA damage checkpoints: from initiation to recovery or adaptation. Curr Opin Cell Biol 19, 238–245. PubMed

Gonzalez Besteiro MA & Gottifredi V (2015) The fork and the kinase: a DNA replication tale from a CHK1 perspective. Mutat Res Rev Mutat Res 763, 168–180. PubMed PMC

Kastan MB & Bartek J (2004) Cell‐cycle checkpoints and cancer. Nature 432, 316–323. PubMed

Dai Y & Grant S (2010) New insights into checkpoint kinase 1 in the DNA damage response signaling network. Clin Cancer Res 16, 376–383. PubMed PMC

van Jaarsveld MTM, Deng D, Wiemer EAC & Zi Z (2019) Tissue‐specific Chk1 activation determines apoptosis by regulating the balance of p53 and p21. iScience 12, 27–40. PubMed PMC

Smith J, Tho LM, Xu N & Gillespie DA (2010) The ATM‐Chk2 and ATR‐Chk1 pathways in DNA damage signaling and cancer. Adv Cancer Res 108, 73–112. PubMed

Weber AM & Ryan AJ (2015) ATM and ATR as therapeutic targets in cancer. Pharmacol Ther 149, 124–138. PubMed

Zeman MK & Cimprich KA (2014) Causes and consequences of replication stress. Nat Cell Biol 16, 2–9. PubMed PMC

Karanika S, Karantanos T, Li L, Wang J, Park S, Yang G, Zuo X, Song JH, Maity SN, Manyam GC et al (2017) Targeting DNA damage response in prostate cancer by inhibiting androgen receptor‐CDC6‐ATR‐Chk1 signaling. Cell Rep 18, 1970–1981. PubMed PMC

Li L, Chang W, Yang G, Ren C, Park S, Karantanos T, Karanika S, Wang J, Yin J, Shah PK et al (2014) Targeting poly(ADP‐ribose) polymerase and the c‐Myb‐regulated DNA damage response pathway in castration‐resistant prostate cancer. Sci Signal 7, ra47. PubMed PMC

Samadder P, Suchankova T, Hylse O, Khirsariya P, Nikulenkov F, Drápela S, Straková N, Vaňhara P, Vašíčková K, Kolářová H et al (2017) Synthesis and profiling of a novel potent selective inhibitor of CHK1 kinase possessing unusual N‐trifluoromethylpyrazole pharmacophore resistant to metabolic N‐dealkylation. Mol Cancer Ther 16, 1831–1842. PubMed

Klaeger S, Heinzlmeir S, Wilhelm M, Polzer H, Vick B, Koenig P‐A, Reinecke M, Ruprecht B, Petzoldt S, Meng C et al (2017) The target landscape of clinical kinase drugs. Science 358, eaan4368. PubMed PMC

Boudny M, Zemanova J, Khirsariya P, Borsky M, Verner J, Cerna J, Oltova A, Seda V, Mraz M, Jaros J et al (2019) Novel CHK1 inhibitor MU380 exhibits significant single‐agent activity in TP53‐mutated chronic lymphocytic leukemia cells. Haematologica 104, 2443–2455. PubMed PMC

Puhr M, Hoefer J, Schafer G, Erb HH, Oh SJ, Klocker H, Heidegger I, Neuwirt H & Culig Z (2012) Epithelial‐to‐mesenchymal transition leads to docetaxel resistance in prostate cancer and is mediated by reduced expression of miR‐200c and miR‐205. Am J Pathol 181, 2188–2201. PubMed

O'Neill AJ, Prencipe M, Dowling C, Fan Y, Mulrane L, Mulrane L, Gallagher WM, O'Connor D, O'Connor R, Devery A et al (2011) Characterisation and manipulation of docetaxel resistant prostate cancer cell lines. Mol Cancer 10, 126. PubMed PMC

van Weerden WM, Bangma C & de Wit R (2009) Human xenograft models as useful tools to assess the potential of novel therapeutics in prostate cancer. Br J Cancer 100, 13–18. PubMed PMC

de Morree ES, Bottcher R, van Soest RJ, Aghai A, de Ridder CM, Gibson AA, Mathijssen RHJ, Burger H, Wiemer EAC, Sparreboom A et al (2016) Loss of SLCO1B3 drives taxane resistance in prostate cancer. Br J Cancer 115, 674–681. PubMed PMC

Patil M, Pabla N & Dong Z (2013) Checkpoint kinase 1 in DNA damage response and cell cycle regulation. Cell Mol Life Sci 70, 4009–4021. PubMed PMC

Bryant C, Rawlinson R & Massey AJ (2014) Chk1 inhibition as a novel therapeutic strategy for treating triple‐negative breast and ovarian cancers. BMC Cancer 14, 570. PubMed PMC

Liang M, Zhao T, Ma L & Guo Y (2018) CHK1 inhibition sensitizes pancreatic cancer cells to gemcitabine via promoting CDK‐dependent DNA damage and ribonucleotide reductase downregulation. Oncol Rep 39, 1322–1330. PubMed

Koh SB, Courtin A, Boyce RJ, Boyle RG, Richards FM & Jodrell DI (2015) CHK1 inhibition synergizes with gemcitabine initially by destabilizing the DNA replication apparatus. Cancer Res 75, 3583–3595. PubMed

Isono M, Hoffmann MJ, Pinkerneil M, Sato A, Michaelis M, Cinatl J, Niegisch Günter & Schulz WA et al (2017) Checkpoint kinase inhibitor AZD7762 strongly sensitises urothelial carcinoma cells to gemcitabine. J Exp Clin Cancer Res 36, 1. PubMed PMC

Italiano A, Infante JR, Shapiro GI, Moore KN, LoRusso PM, Hamilton E, Cousin S, Toulmonde M, Postel‐Vinay S, Tolaney S et al (2018) Phase I study of the checkpoint kinase 1 inhibitor GDC‐0575 in combination with gemcitabine in patients with refractory solid tumors. Ann Oncol 29, 1304–1311. PubMed

Niida H, Katsuno Y, Banerjee B, Hande MP & Nakanishi M (2007) Specific role of Chk1 phosphorylations in cell survival and checkpoint activation. Mol Cell Biol 27, 2572–2581. PubMed PMC

Guzi TJ, Paruch K, Dwyer MP, Labroli M, Shanahan F, Davis N, Taricani L, Wiswell D, Seghezzi W, Penaflor E et al (2011) Targeting the replication checkpoint using SCH 900776, a potent and functionally selective CHK1 inhibitor identified via high content screening. Mol Cancer Ther 10, 591–602. PubMed

Laroche‐Clary A, Lucchesi C, Rey C, Verbeke S, Bourdon A, Chaire V, Algéo M‐P, Cousin S, Toulmonde M, Vélasco V et al (2018) CHK1 inhibition in soft‐tissue sarcomas: biological and clinical implications. Ann Oncol 29, 1023–1029. PubMed

Zemanova J, Hylse O, Collakova J, Vesely P, Oltova A, Borsky M, Zaprazna K, Kasparkova M, Janovska P, Verner J et al (2016) Chk1 inhibition significantly potentiates activity of nucleoside analogs in TP53‐mutated B‐lymphoid cells. Oncotarget 7, 62091–62106. PubMed PMC

Ma CX, Janetka JW & Piwnica‐Worms H (2011) Death by releasing the breaks: CHK1 inhibitors as cancer therapeutics. Trends Mol Med 17, 88–96. PubMed PMC

Del Nagro CJ, Choi J, Xiao Y, Rangell L, Mohan S, Pandita A, Zha J, Jackson PK & O'Brien T (2014) Chk1 inhibition in p53‐deficient cell lines drives rapid chromosome fragmentation followed by caspase‐independent cell death. Cell Cycle 13, 303–314. PubMed PMC

Cappella P, Tomasoni D, Faretta M, Lupi M, Montalenti F, Viale F, Banzato F, D'Incalci M & Ubezio P (2001) Cell cycle effects of gemcitabine. Int J Cancer 93, 401–408. PubMed

Pauwels B, Korst AE, Pattyn GG, Lambrechts HA, Van Bockstaele DR, Vermeulen K, Lenjou M, de Pooter CMJ, Vermorken JB & Lardon F (2003) Cell cycle effect of gemcitabine and its role in the radiosensitizing mechanism in vitro . Int J Radiat Oncol Biol Phys 57, 1075–1083. PubMed

Merlin T, Brandner G & Hess RD (1998) Cell cycle arrest in ovarian cancer cell lines does not depend on p53 status upon treatment with cytostatic drugs. Int J Oncol 13, 1007–1016. PubMed

Parsels LA, Morgan MA, Tanska DM, Parsels JD, Palmer BD, Booth RJ, Denny WA, Canman CE, Kraker AJ, Lawrence TS et al (2009) Gemcitabine sensitization by checkpoint kinase 1 inhibition correlates with inhibition of a Rad51 DNA damage response in pancreatic cancer cells. Mol Cancer Ther 8, 45–54. PubMed PMC

Syljuasen RG, Sorensen CS, Hansen LT, Fugger K, Lundin C, Johansson F, Helleday T, Sehested M, Lukas J & Bartek J (2005) Inhibition of human Chk1 causes increased initiation of DNA replication, phosphorylation of ATR targets, and DNA breakage. Mol Cell Biol 25, 3553–3562. PubMed PMC

King C, Diaz HB, McNeely S, Barnard D, Dempsey J, Blosser W, Beckmann R, Barda D & Marshall MSs (2015) LY2606368 causes replication catastrophe and antitumor effects through CHK1‐dependent mechanisms. Mol Cancer Ther 14, 2004–2013. PubMed

Manic G, Signore M, Sistigu A, Russo G, Corradi F, Siteni S, Musella M, Vitale S, De Angelis ML, Pallocca M et al (2018) CHK1‐targeted therapy to deplete DNA replication‐stressed, p53‐deficient, hyperdiploid colorectal cancer stem cells. Gut 67, 903–917. PubMed PMC

Ma CX, Cai S, Li S, Ryan CE, Guo Z, Schaiff WT, Lin L, Hoog J, Goiffon RJ, Prat A et al (2012) Targeting Chk1 in p53‐deficient triple‐negative breast cancer is therapeutically beneficial in human‐in‐mouse tumor models. J Clin Invest 122, 1541–1552. PubMed PMC

Hwang BJ, Adhikary G, Eckert RL & Lu AL (2018) Chk1 inhibition as a novel therapeutic strategy in melanoma. Oncotarget 9, 30450–30464. PubMed PMC

David L, Fernandez‐Vidal A, Bertoli S, Grgurevic S, Lepage B, Deshaies D, Prade N, Cartel M, Larrue C, Sarry J‐E et al (2016) CHK1 as a therapeutic target to bypass chemoresistance in AML. Sci Signal 9, ra90. PubMed

Rundle S, Bradbury A, Drew Y & Curtin NJ (2017) Targeting the ATR‐CHK1 axis in cancer therapy. Cancers (Basel) 9, 41. PubMed PMC

Qiu Z, Oleinick NL & Zhang J (2018) ATR/CHK1 inhibitors and cancer therapy. Radiother Oncol 126, 450–464. PubMed PMC

Sekhar KR, Wang J, Freeman ML & Kirschner AN (2019) Radiosensitization by enzalutamide for human prostate cancer is mediated through the DNA damage repair pathway. PLoS One 14, e0214670. PubMed PMC

Polkinghorn WR, Parker JS, Lee MX, Kass EM, Spratt DE, Iaquinta PJ, Arora VK, Yen W‐F, Cai L, Zheng D et al (2013) Androgen receptor signaling regulates DNA repair in prostate cancers. Cancer Discov 3, 1245–1253. PubMed PMC

Cronauer MV, Klocker H, Talasz H, Geisen FH, Hobisch A, Radmayr C, Böck G, Culig Z, Schirmer M, Reissigl A et al (1996) Inhibitory effects of the nucleoside analogue gemcitabine on prostatic carcinoma cells. Prostate 28, 172–181. PubMed

Morant R, Bernhard J, Maibach R, Borner M, Fey MF, Thürlimann B, Jacky E, Trinkler F, Bauer J, Zulian G et al (2000) Response and palliation in a phase II trial of gemcitabine in hormone‐refractory metastatic prostatic carcinoma. Swiss Group for Clinical Cancer Research (SAKK). Ann Oncol 11, 183–188. PubMed

Lee JL, Ahn JH, Choi MK, Kim Y, Hong SW, Lee K‐H, Jeong I‐G, Song C, Hong B‐S, Hong JH et al (2014) Gemcitabine‐oxaliplatin plus prednisolone is active in patients with castration‐resistant prostate cancer for whom docetaxel‐based chemotherapy failed. Br J Cancer 110, 2472–2478. PubMed PMC

Seo HK, Lee SJ, Kwon WA & Jeong KC (2020) Docetaxel‐resistant prostate cancer cells become sensitive to gemcitabine due to the upregulation of ABCB1. Prostate 80, 453–462. PubMed