Exploring the ATR-CHK1 pathway in the response of doxorubicin-induced DNA damages in acute lymphoblastic leukemia cells

Abstract

Doxorubicin (Dox) is one of the most commonly used anthracyclines for the treatment of solid and hematological tumors such as B−/T cell acute lymphoblastic leukemia (ALL). Dox compromises topoisomerase II enzyme functionality, thus inducing structural damages during DNA replication and causes direct damages intercalating into DNA double helix. Eukaryotic cells respond to DNA damages by activating the ATM-CHK2 and/or ATR-CHK1 pathway, whose function is to regulate cell cycle progression, to promote damage repair, and to control apoptosis. We evaluated the efficacy of a new drug schedule combining Dox and specific ATR (VE-821) or CHK1 (prexasertib, PX) inhibitors in the treatment of human B−/T cell precursor ALL cell lines and primary ALL leukemic cells. We found that ALL cell lines respond to Dox activating the G2/M cell cycle checkpoint. Exposure of Dox-pretreated ALL cell lines to VE-821 or PX enhanced Dox cytotoxic effect. This phenomenon was associated with the abrogation of the G2/M cell cycle checkpoint with changes in the expression pCDK1 and cyclin B1, and cell entry in mitosis, followed by the induction of apoptosis. Indeed, the inhibition of the G2/M checkpoint led to a significant increment of normal and aberrant mitotic cells, including those showing tripolar spindles, metaphases with lagging chromosomes, and massive chromosomes fragmentation. In conclusion, we found that the ATR-CHK1 pathway is involved in the response to Dox-induced DNA damages and we demonstrated that our new in vitro drug schedule that combines Dox followed by ATR/CHK1 inhibitors can increase Dox cytotoxicity against ALL cells, while using lower drug doses. Graphical abstract • Doxorubicin activates the G2/M cell cycle checkpoint in acute lymphoblastic leukemia (ALL) cells. • ALL cells respond to doxorubicin-induced DNA damages by activating the ATR-CHK1 pathway. • The inhibition of the ATR-CHK1 pathway synergizes with doxorubicin in the induction of cytotoxicity in ALL cells. • The inhibition of ATR-CHK1 pathway induces aberrant chromosome segregation and mitotic spindle defects in doxorubicin-pretreated ALL cells.

Long circulation and tumor-targeting biomimetic nanoparticles for efficient chemo/photothermal synergistic therapy

“…The heat generated by the PDA shell layer under NIR light enhanced the toxicity and chemical reactions between the drug and the DNA of HeLa cells and inhibited the activity of DNA repair enzymes in post-chemotherapy lesions. 41 It disrupted the synthesis and repair of tumor cell DNA and led to death of HeLa cells. 42 In Fig.…”

Indigofera suffruticosa aerial parts extract induce G2/M arrest and ATR/CHK1 pathway in Jurkat cells

“…From a chemical structure perspective, tryptanthrin, like the TopoI inhibitor camptothecins and the TopoII inhibitor doxorubicin, possesses a planar polycyclic structure. Although camptothecins and doxorubicin have different molecular mechanisms, both can induce DNA damage and G2/M cell cycle arrest [ 36 , 37 ]. Interestingly, previous studies have shown that ALL cells respond to doxorubicin-induced DNA damages by activating the ATR-CHK1 pathway [ 36 ].…”

“…Although camptothecins and doxorubicin have different molecular mechanisms, both can induce DNA damage and G2/M cell cycle arrest [ 36 , 37 ]. Interestingly, previous studies have shown that ALL cells respond to doxorubicin-induced DNA damages by activating the ATR-CHK1 pathway [ 36 ]. Additionally, derivatives of tryptanthrin have also been found to exhibit inhibitory effects on TopoII [ 19 ].…”

Targeting the DNA damage response in hematological malignancies

“…In B-ALL cells, as with AML, the pol 1 inhibitor CX5461 activates the ATR pathway and mediates G2 checkpoint arrest, and thus induced apoptosis synergistically in combination with VE-822 ( 45 ), providing another alternative combination strategy through exacerbation of replication stress. Treatment of ALL cell lines and primary ALL cells with VE-821 in combination with doxorubicin also proved effective ( 46 ).…”

“…In cell lines prexasertib was synergistic with the tyrosine kinase inhibitor, imatinib, and purine nucleoside antimetabolite, clofarabine, with the prexasertib/imatinib combination also showing activity against primary leukemic blasts ( 84 ). Prexasertib, also acted as chemosensitizer in combination with doxorubicin in ALL cell lines and primary ALL cells ( 46 ). The combination of CHK1 inhibition with other targeted agents as well as immunotherapies against ALL are likely to be more promising than their combination with cytotoxic agents given the hematologic toxicity and the chemo resistant nature of the relapsed ALL.…”