Antitumor activity and toxicological properties of doxorubicin conjugated to α,β-poly[(2-hydroxyethyl)-L-aspartamide] administered intraperitoneally in mice

Embryonic stem cell-derived cardiomyocytes for the treatment of doxorubicin-induced cardiomyopathy

BACKGROUND

Doxorubicin (Dox) is a chemotherapy drug with limited application due to cardiotoxicity that may progress to heart failure. This study aims to evaluate the role of cardiomyocytes derived from mouse embryonic stem cells (CM-mESCs) in the treatment of Dox-induced cardiomyopathy (DIC) in mice.

METHODS

The mouse embryonic stem cell (mESC) line E14TG2A was characterized by karyotype analysis, gene expression using RT-PCR and immunofluorescence. Cells were transduced with luciferase 2 and submitted to cardiac differentiation. Total conditioned medium (TCM) from the CM-mESCs was collected for proteomic analysis. To establish DIC in CD1 mice, Dox (7.5 mg/kg) was administered once a week for 3 weeks, resulting in a cumulative Dox dose of 22.5 mg/kg. At the fourth week, a group of animals was injected intramyocardially with CM-mESCs (8 × 10⁵ cells). Cells were tracked by a bioluminescence assay, and the body weight, echocardiogram, electrocardiogram and number of apoptotic cardiomyocytes were evaluated.

RESULTS

mESCs exhibited a normal karyotype and expressed pluripotent markers. Proteomic analysis of TCM showed proteins related to the negative regulation of cell death. CM-mESCs presented ventricular action potential characteristics. Mice that received Dox developed heart failure and showed significant differences in body weight, ejection fraction (EF), end-systolic volume (ESV), stroke volume (SV), heart rate and QT and corrected QT (QTc) intervals when compared to the control group. After cell or placebo injection, the Dox + CM-mESC group showed significant increases in EF and SV when compared to the Dox + placebo group. Reduction in ESV and QT and QTc intervals in Dox + CM-mESC-treated mice was observed at 5 or 30 days after cell treatment. Cells were detected up to 11 days after injection. The Dox + CM-mESC group showed a significant reduction in the percentage of apoptotic cardiomyocytes in the hearts of mice when compared to the Dox + placebo group.

CONCLUSIONS

CM-mESC transplantation improves cardiac function in mice with DIC.

Protective effect of berberine on doxorubicin‑induced acute hepatorenal toxicity in rats

Doxorubicin (DOX), a potent broad‑spectrum chemotherapeutic agent used for the treatment of several types of cancer, is largely limited due to its serious side effects on non‑target organs. Thus, the present study aimed to investigate whether berberine (Ber), an isoquinoline alkaloid, could reduce DOX‑induced acute hepatorenal toxicity in rats. Fifty rats were randomly divided into five groups: i) Control group, ii) DOX group, iii) DOX+Ber (5 mg kg) group; iv) DOX+Ber (10 mg kg), and v) DOX+Ber (20 mg kg) group. In the tests, body weight, organ index, general condition and mortality were observed. In addition, the serum levels of alanine transaminase (ALT), aspartate aminotransferase (AST), total cholesterol (TCHO) and blood urea nitrogen (BUN) were determined to evaluate hepatorenal function. Hepatorenal toxicity was further assessed using hematoxylin and eosin stained sections. Furthermore, the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and malondialdehyde (MDA) in rat serum or tissue homogenate were also assessed to determine the mechanisms of action. Results suggested that pretreatment with Ber ameliorated the DOX‑induced liver and kidney injury by lowering the serum ALT, AST, TCHO and BUN levels, and the damage observed histologically, such as hemorrhage and focal necrosis of liver and kidney tissues induced by DOX were also attenuated by Ber. Furthermore, Ber also exerted certain antioxidative properties through reversing the changes in the levels of MDA, SOD, GSH and MDA induced by DOX. These findings indicate that Ber has protective effects against DOX‑induced acute hepatorenal toxicity in rats. Combination of Ber with DOX is a novel strategy that has the potential for protecting against DOX‑induced hepatorenal toxicity in clinical practice.

Acetic acid induces cell death: an in vitro study using normal rat gastric mucosal cell line and rat and human gastric cancer and mesothelioma cell lines

BACKGROUND AND AIM

We recently reported that topical application of acetic acid promptly caused tumor necrosis in a mouse model of gastric cancer. The aim of the present study was to examine whether acetic acid can directly induce cancer cell death.

METHODS

Rat gastric epithelial cell line (RGM-1), rat gastric carcinoma cell line (RGK-1), human gastric cancer cell line (KATO III), and human mesothelioma cell lines (ACC-MESO1 and MSTO-211H) were used. Acetic acid was added into the cell culture at different concentrations for different time periods. Cell death was analyzed by MTT assay, flow cytometry, and trypan blue exclusion test.

RESULTS

Acetic acid promptly induced the cell death of RGM-1, RGK-1 cells, and KATO III cells in a concentration-dependent manner from 0.01% to 0.5%. Acetic acid at 0.5% for 1 min induced the cell death by 80%. RGK-1 cells were more sensitive to acetic acid than RGM-l cells. KATO III cells were more sensitive to acetic acid than RGK-1 cells. Acetic acid at 0.5% for 10 min induced almost complete cell death of ACC-MESO1 and MSTO-211H.

CONCLUSIONS

Acetic acid is a powerful anticancer agent. Topical application of acetic acid may be a feasible approach for the treatments of gastric cancer and possibly other malignancies.

Development of doxorubicin-induced chronic cardiotoxicity in the B6C3F1 mouse model

Serum levels of cardiac troponins serve as biomarkers of myocardial injury. However, troponins are released into the serum only after damage to cardiac tissue has occurred. Here, we report development of a mouse model of doxorubicin (DOX)-induced chronic cardiotoxicity to aid in the identification of predictive biomarkers of early events of cardiac tissue injury. Male B6C3F(1) mice were administered intravenous DOX at 3mg/kg body weight, or an equivalent volume of saline, once a week for 4, 6, 8, 10, 12, and 14weeks, resulting in cumulative DOX doses of 12, 18, 24, 30, 36, and 42mg/kg, respectively. Mice were sacrificed a week following the last dose. A significant reduction in body weight gain was observed in mice following exposure to a weekly DOX dose for 1week and longer compared to saline-treated controls. DOX treatment also resulted in declines in red blood cell count, hemoglobin level, and hematocrit compared to saline-treated controls after the 2nd weekly dose until the 8th and 9th doses, followed by a modest recovery. All DOX-treated mice had significant elevations in cardiac troponin T concentrations in plasma compared to saline-treated controls, indicating cardiac tissue injury. Also, a dose-related increase in the severity of cardiac lesions was seen in mice exposed to 24mg/kg DOX and higher cumulative doses. Mice treated with cumulative DOX doses of 30mg/kg and higher showed a significant decline in heart rate, suggesting drug-induced cardiac dysfunction. Altogether, these findings demonstrate the development of DOX-induced chronic cardiotoxicity in B6C3F(1) mice.

Recent advances in the molecular imaging of programmed cell death: part I--pathophysiology and radiotracers

In humans, apoptosis (programmed cell death) is the most common form of cell death after necrosis. Apoptosis is a series of genetically preprogrammed biochemical and morphologic energy-requiring events that, after a specific external or internal stimulus, results in the physiologic disappearance of a cell via its self-disintegration and packaging of its contents into membrane vesicles called apoptotic bodies. Apoptotic bodies can readily be ingested, with their nutrients and even organelles recycled by neighboring cells or phagocytes without local inflammation. In contrast, necrosis is characterized by the primary loss of plasma membrane integrity and the uncontrolled release of a cell's contents, often causing local inflammation, tissue damage, and scarring. Alternate forms of cell death also exist, associated with specific molecular mechanisms involving enzymes, organelles, genes, external stimuli, or blockade of normal cell proliferation. In this review we will briefly outline the molecular mechanisms of apoptosis that can be imaged with radiotracers now under development.

Multimodality molecular imaging of apoptosis in oncology

OBJECTIVE

The purposes of this review are to describe the signaling pathways of and the cellular changes that occur with apoptosis and other forms of cell death, summarize tracers and modalities used for imaging of apoptosis, delineate the relation between apoptosis and inhibition of protein translation, and describe spectroscopic technologies that entail high-frequency ultrasound and infrared and midinfrared light in characterizing the intracellular events of apoptosis.

CONCLUSION

Apoptosis is a highly orchestrated set of biochemical and morphologic cellular events. These events present many potential targets for the imaging of apoptosis in vivo. Imaging of apoptosis can facilitate early assessment of anticancer treatment before tumor shrinkage, which may increase the effectiveness of delivery of chemotherapy and radiation therapy and speed drug development.

Intraperitoneal administration of novel doxorubicin loaded polymeric delivery systems against peritoneal carcinomatosis: experimental study in a murine model of ovarian cancer

OBJECTIVE

Peritoneal spread is an adverse outcome in ovarian cancer. Despite clinical efficiency, intraperitoneal (i.p.) chemotherapy after cytoreductive surgery is associated with high systemic and local toxicity. Two polymer-drug delivery systems (P-HYD1-DOX and P-HYD2-DOX) were developed for i.p. administration by conjugating doxorubicin (DOX) to a poly(l-Lysine citramide) polymer carrier with a hydrazone-based degradable spacer. The aim of this study was to assess the antitumoral efficacy of these two conjugates in a xenograft model of human ovarian carcinomatosis.

METHODS

Peritoneal carcinomatosis was generated in athymic mice by i.p. injection of SKOV3-Luc cells. Free DOX, P-HYD1-DOX and P-HYD2-DOX solutions were administered i.p. at the same dose of 10 mg/kg (DOX eq.). For each treatment, tumor load and therapeutic efficacy were compared to untreated mice and assessed by bioluminescence imaging and survival rates. Toxicity profiles in each group and biodistribution of P-HYD2-DOX after i.p. administration were also determined.

RESULTS

P-HYD-1-DOX and P-HYD-2-DOX demonstrated significant antitumoral efficacy against peritoneal carcinomatosis. Compared to untreated group, P-HYD1-DOX improved median survival times from 58 to 105 days. For P-HYD2-DOX, median survival was not reached after a follow-up of 120 days. Bioluminescence showed high efficacy of P-HYD-2-DOX compared to free DOX but the difference was not significant. Biodistribution study confirmed that free and active DOX were successively released from P-HYD2-DOX in vivo. P-HYD-DOX conjugates were well tolerated by mice after i.p. injection.

CONCLUSION

P-HYD-DOX conjugates demonstrated significant activity against peritoneal carcinomatosis in a xenograft model of ovarian carcinomatosis and their ability to release active DOX in i.p. deposits and tumor. These features are of clinical interest for i.p. administration in the treatment of ovarian peritoneal carcinomatosis after cytoreductive surgery.