Cytotoxicity of Arginine Deprivation to AML Cells is Mediated by Autophagy

الموضوعات

علوم بحتة وطبيعية

الملخص

In this study, we assess the activation of autophagy in AML cells following arginine deprivation, the mechanism of its activation, and its impact on cell cytotoxicity. Arginine deprivation was induced using a pegylated recombinant human Arginase I [HuArgI(Co)-PEG5000], in which the two Mn2+ ions of the active site have been replaced with Co2+ ions. AML cell lines were tested, and activation of autophagy was determined by staining for autophagosomes on flow cytometry. The impact of autophagy on cell cytotoxicity of arginine deprivation was assessed through inhibition of autophagy using the downstream autophagy inhibitor chloroquine (CQ). [HuArgI(Co)-PEG5000]-induced arginine deprivation led to significant and sustained activation of autophagy starting at 24 hours and lasting up to 120 hours following arginine deprivation in all cell lines. Inhibition of autophagy, using chloroquine, led to a significant decrease in cell cytotoxicity evident at 48 hours and up to 120 hours. This indicates that activation of autophagy in response to arginine deprivation, is leading to AML cell death (death by autophagy). This was further confirmed by the fact that cell death observed following arginine deprivation in AML cells was caspase-independent and nonapoptotic. Moreover, AML cells were shown to overexpress the major key player in the biosynthesis of L-arginine; Argininosuccinate Synthetase-1 (ASS-1) upon arginine deprivation without it conferring resistance to death by autophagy induced by HuArgI(Co)-PEG5000. Addition of the ROS scavenger N-acetyl-cysteine (NAC) repressed the autophagic response and reversed cytotoxicity of arginine deprivation to AML cells, indicating that the activation of autophagy is induced following ROS generation. Finally, our study demonstrates that in AML cells, arginine deprivation induces autophagy activation leading to cell death irrespective the overexpression of ASS-1. We have also shown that the activation of autophagy and the subsequent death by autophagy of AML cells is induced through generation of ROS.

روابط وملفات

التعريف والنوع

رقم الوثيقة

0240edb3-59f3-40be-ac76-39d1a00acba2

رقم العقد

0

نوع الوسائط

Crawler

نوع المحتوى

الرسائل العلمية

صيغة المصدر

رسائل ماجيستير

نوع الملف

pdf text

أسماء الملفات

2212733_1.pdf

بيانات النشر

ألقاب المؤلفين

[{"name_ar":"Fatima Taki","title_ar":"اعداد","title_en":"Preparation"},{"name_ar":"Ralph Abi Habib","title_ar":"اشراف","title_en":"Supervision"}]

اللغة

English

المصدر والدورية

اسم المصدر

Cytotoxicity of Arginine Deprivation to AML Cells is Mediated by Autophagy

المحتوى والصفحات

عدد الصفحات

0

كلمات الباحثين

Deprivation to AML

إشراف وإعداد

الإشراف

Ralph Abi Habib

الإعداد

Fatima Taki

الاقتباسات الببليوغرافية