Patients with acute myeloid leukemia (AML) often have a poor prognosis due to drug resistance, which is regarded as a tough problem during the period of clinical therapeutics. It has been reported that autophagy, an important event in various cellular processes, plays a crucial role in mediating drug-resistance to cancer cells. Our study attempts to comparatively investigate the differences of basic and induced autophagic activity between drug-sensitive and multidrug-resistant AML cells. The level of basic autophagy in K562/ADM cells was higher than that in K562 cells, which could be characterized by more cytosolic contents-packaged autophagic vacuoles in K562/ADM cells when compared to that in K562 cells. The observation of MDC staining showed that the fluorescent intensity of autophagosomes in K562/ADM cells was stronger than that in K562 cells. The expression of Beclin1 and the ratio of LC3-II to LC3-I were distinctly higher in K562/ADM cells, however, P62 protein was relatively lower in K562/ADM cells. Furthermore, we found that nutrient depletion could induce autophagic activity of both cell lines. However, autophagic activity of K562/ADM cells was always maintained at a higher level in contrast with K562 cells. ADM (Adriamycin) was also capable of inducing autophagic activity of K562 and K562/ADM cells, but the autophagic alteration in K562 cells appeared earlier. Taken together, our findings suggest that autophagy exerts an important effect on formation and maintenance of drug-resistance in AML cells.
[1]Fudan Univ, Obstet & Gynecol Hosp, 413 Zhaozhou Rd, Shanghai 200011, Peoples R China.
[2]Fudan Univ, Acad Integrat Med, Shanghai, Peoples R China.
[3]Fudan Univ, Shanghai Med Coll, Lab Reprod Immunol, Hosp & Inst Obstet & Gynecol, Shanghai, Peoples R China.
[4]Shanghai Key Lab Female Reprod Endocrine Related, Shanghai, Peoples R China.
[5]Lanzhou Univ, Sch Basic Med Sci, Key Lab Preclin Study New Drugs Gansu Prov, 199 Donggang West Rd, Lanzhou 730000, Gansu, Peoples R China.
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