Doxorubicin Paradoxically Ameliorates Tumor-Induced Inflammation in Young Mice

Sex-related differences in delayed doxorubicin-induced cardiac dysfunction in C57BL/6 mice

Cancer survivors may experience long-term cardiovascular complications due to chemotherapeutic drugs such as doxorubicin (DOX). The exact mechanism of delayed DOX-induced cardiotoxicity has not been fully elucidated. Sex is an important risk factor for DOX-induced cardiotoxicity. In the current study, we identified sex differences in delayed DOX-induced cardiotoxicity and determined the underlying molecular determinants of the observed sexual dimorphism. Five-week-old male and female mice were administered intraperitoneal injections of DOX (4 mg/kg/week) or saline for 6 weeks. Echocardiography was performed 5 weeks after the last dose of DOX to evaluate cardiac function. Thereafter, mice were sacrificed and gene expression of markers of apoptosis, senescence, and inflammation was measured by PCR in hearts and livers. Proteomic profiling of the heart from both sexes was conducted to determine differentially expressed proteins (DEPs). Only DOX-treated male, but not female, mice demonstrated cardiac dysfunction, cardiac atrophy, and upregulated cardiac expression of Nppb and Myh7. No sex-related differences were observed in DOX-induced expression of most apoptotic, senescence, and pro-inflammatory markers. However, the gene expression of Trp53 was significantly reduced in hearts of DOX-treated female mice only. The anti-inflammatory marker Il-10 was significantly reduced in hearts of DOX-treated male mice only, while the pro-inflammatory marker Il-1α was significantly reduced in livers of DOX-treated female mice only. Gene expression of Tnf-α was reduced in hearts of both DOX-treated male and female mice. Proteomic analysis identified several DEPs after DOX treatment in a sex-specific manner, including anti-inflammatory acute phase proteins. This is the first study to assess sex-specific proteomic changes in a mouse model of delayed DOX-induced cardiotoxicity. Our proteomic analysis identified several sexually dimorphic DEPs, many of which are associated with the anti-inflammatory marker Il-10.

Antioxidant and anti-inflammatory potential of crocin on the doxorubicin mediated hepatotoxicity in Wistar rats

Doxorubicin (DXR) is widely used in cancer treatment. However, it has not yet been possible to prevent the side effects of DXR. The aim of this study was to investigate the hepatoprotective effect of crocin against DXR used in cancer treatment. For this reason; forty Wistar rats (male-250-300 g) were allocated into four groups (n = 10/group): Control, Crocin, DXR and DXR+Crocin. Control and Crocin groups were administered saline and crocin (40 mg/kg, i.p) for 15 days, respectively. DXR group, cumulative dose 12 mg/kg DXR, was administered for 12 days via 48 h intervals in six injections (2 mg/kg each, i.p). DXR+Crocin group, crocin (40 mg/kg-i.p) was administered for 15 days, and DXR was given as in the DXR group. The results revealed that serum liver markers (alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) increased significantly after DXR administration but recovered after crocin therapy. In addition, lipid peroxidation (MDA), and inflammatory cytokine (TNF-α) increased after DXR application and the antioxidative defense system (GSH, SOD, CAT) significantly decreased and re-achieved by crocin treatment. Our results conclude that crocin treatment was related to ameliorated hepatocellular architecture and reduced hepatic oxidative stress and inflammation in rats with DXR-induced hepatotoxicity.

Juvenile exposure to doxorubicin alters the cardiovascular response to adult-onset psychosocial stress in mice

Childhood cancer survivors have a high risk for premature cardiovascular diseases, mainly due to cardiotoxic cancer treatments such as doxorubicin (DOX). Psychosocial stress is a significant cardiovascular risk factor and an enormous burden in childhood cancer survivors. Although observational studies suggest that psychosocial stress is associated with cardiovascular complications in cancer survivors, there is no translationally relevant animal model to study this interaction. We established a "two-hit" model in which juvenile mice were administered DOX (4 mg/kg/week for 3 weeks), paired to a validated model of chronic subordination stress (CSS) 5 weeks later upon reaching adulthood. Blood pressure, heart rate, and activity were monitored by radio-telemetry. At the end of CSS experiment, cardiac function was assessed by echocardiography. Cardiac fibrosis and inflammation were assessed by histopathologic analysis. Gene expressions of inflammatory and fibrotic markers were determined by PCR. Juvenile exposure to DOX followed by adult-onset CSS caused cardiac fibrosis and inflammation as evident by histopathologic findings and upregulated gene expression of multiple inflammatory and fibrotic markers. Intriguingly, juvenile exposure to DOX blunted CSS-induced hypertension but not CSS-induced tachycardia. There were no significant differences in cardiac function parameters among all groups, but juvenile exposure to DOX abrogated the hypertrophic response to CSS. In conclusion, we established a translationally relevant mouse model of juvenile DOX-induced cardiotoxicity that predisposes to adult-onset stress-induced adverse cardiac remodeling. Psychosocial stress should be taken into consideration in cardiovascular risk stratification of DOX-treated childhood cancer survivors.