Morphological alterations induced by doxorubicin on H9c2 myoblasts: nuclear, mitochondrial, and cytoskeletal targets

Abstract

Doxorubicin (Dox) is a very potent antineoplastic agent used against several types of cancer, despite a cumulative cardiomyopathy that reduces the therapeutic index for treatment. H9c2 myoblast cells have been used as an in vitro model to study biochemical alterations induced by Dox treatment on cardiomyocyte cells. Despite the extensive work already published, few data are available regarding morphological alterations of H9c2 cells during Dox treatment. The purpose of the present work was to evaluate Doxinduced morphological alterations in H9c2 myoblasts, focusing especially on the nuclei, mitochondria, and structural fibrous proteins. Treatment of H9c2 cell with low concentrations of Dox causes alterations in fibrous structural proteins including the nuclear lamina and sarcomeric cardiac myosin, as well as mitochondrial depolarization and fragmentation, membrane blebbing with cell shape changes, and phosphatidylserine externalization. For higher Dox concentrations, more profound alterations are evident, including nuclear swelling with disruption of nuclear membrane structure, mitochondrial swelling, and extensive cytoplasm vacuolization. The results obtained indicate that Dox causes morphological alterations in mitochondrial, nuclear, and fibrous protein structures in H9c2 cells, which are dependent on the drug concentration. Data obtained with the present study allow for a better characterization of the effects of Dox on H9c2 myoblasts, used as a model to study Dox-induced cardiotoxicity. The results obtained also provide new and previously unknown targets that can contribute to understand the mechanisms involved in the cardiotoxicity of Dox.

Monitoring doxorubicin cellular uptake and trafficking using in vitro Raman microspectroscopy: short and long time exposure effects on lung cancer cell lines

“…Nevertheless, it is clear that the DOX concentration inside the combined nuclear regions becomes approximately constant after ~24hrs exposure, after which DOX begins to accumulate in the cytoplasm due to nuclear membrane loss of integrity. (46,53) The behaviour is consistent with saturation of nuclear binding sites after a certain time and any additional drug taken up by cells accumulates in the cytoplasm. (54,55) In order to track the cellular changes associated with the progressive uptake of DOX in the subcellular regions, PLSR was employed, and spectra were regressed against time, progressively increasing the time interval from 0-6 to 0-72hrs.…”

ErbB2 overexpression upregulates antioxidant enzymes, reduces basal levels of reactive oxygen species, and protects against doxorubicin cardiotoxicity

“…Since our results show that ErbB2 overexpression in the heart regulates GPx and Abl kinases, with ROS emission reduced, we sought to determine whether ErbB2 overexpression is protective against oxidative stress and cytotoxicity induced by doxorubicin in H9c2 cells, a cardiomyoblast cell line that is often used as an alternative in vitro model to cardiomyocytes and in doxorubicin toxicity studies (45,54,71). Representative immunoblots of lysates from H9c2 cells with transient overexpression of ErbB2 compared with the vector control (Fig.…”

Enhanced antitumor activity of doxorubicin in breast cancer through the use of poly(butylcyanoacrylate) nanoparticles

“…In fact, morphological and ultrastructural changes caused by DOX in H9C2 rat myoblast cells (chromatin clumping, swollen mitochondria, disruption of the nuclear membrane structure, and cytoplasm vacuolization) were directly associated with the drug concentration. 47 The actual mechanism(s) that results in the significantly higher cytotoxicity of DOX-loaded PBCA NPs against MCF-7 and E0771 cells compared with the cytotoxicity of free DOX is not clear. It is known that, whereas the free drug enters cells by simple diffusion, drug-loaded NPs may provide a different cell entry mechanism such as endocytosis, pinocytosis, or phagocytosis, which is still under discussion.…”