Doxorubicin Paradoxically Ameliorates Tumor-Induced Inflammation in Young Mice

Losmapimod ameliorates doxorubicin-induced cardiotoxicity through attenuating senescence and inflammatory pathways

Irreversible cardiotoxicity limits the clinical application of doxorubicin (DOX). DOX-induced cardiotoxicity has been associated with induction of senescence and activation of the p38 MAPK pathway. Losmapimod (LOSM), an orally active p38 MAPK inhibitor, is an anti-inflammatory agent with cardioprotective effects. Nevertheless, the effect of LOSM against DOX-induced cardiotoxicity has not been reported. In this study, we determined the effects of LOSM on DOX-induced chronic cardiotoxicity in C57BL/6 N mice. Five-week-old C57BL/6 N mice were fed diet containing LOSM (estimated daily intake 12 mg/kg/day) or a control diet for four days. Thereafter, mice were randomized to receive six weekly intraperitoneal injections of either DOX (4 mg/kg) or saline. Three days after the last injection, cardiac function was assessed by trans-thoracic echocardiography. Activation of p38, JNK, and ERK1/2 MAPKs were assessed by immunoblotting in the heart and liver. Gene expressions of senescence, inflammatory, oxidative stress, and mitochondrial function markers were quantified using real-time PCR and serum inflammatory markers were assessed by Luminex. Our results demonstrated that LOSM attenuated p38 MAPK activation, ameliorated DOX-induced cardiac dysfunction, and abrogated DOX-induced expression of the senescence marker p21Cip1. Additionally, LOSM demonstrated anti-inflammatory effects, with reduced cardiac Il-1α and Il-6 gene expression in DOX-treated mice. Systemic inflammation, assessed by serum cytokine levels, showed decreased IL-6 and CXCL1 in both DOX-treated mice and mice on LOSM diet. LOSM significantly increased mitofusin2 gene expression, which may enhance mitochondrial fusion. These findings underscore the potential therapeutic efficacy of p38 MAPK inhibition, exemplified by LOSM, in ameliorating DOX-induced cardiotoxicity, senescence, and inflammation.

Protective effect of Chlorella vulgaris on testicular damage, sperm parameters, androgen production, apoptosis and oxidative stress index in male rats following doxorubicin administration

Doxorubicin (DOX) is a chemotherapy agent associated with adverse effects on male reproductive health. Chlorella vulgaris (ChV) is a potent natural antioxidant with promising applications in maintaining health and preventing oxidative stress-related diseases. The present study aimed to investigate the protective effect of ChV on DOX-induced testicular toxicity. Twenty-five Wistar rats (230 ± 20 g) were randomly assigned to five groups (n = 5), including the control group, sham group (received normal saline by oral gavage daily and intraperitoneally (IP) once a week), DOX group (3 mg/kg; once a week; IP), ChV group (300 mg/kg/day; by oral gavage), and DOX (3 mg/kg; once a week; IP) + ChV (300 mg/kg/day; by oral gavage) group. After 8 weeks of treatment, the rats were euthanized and serum testosterone level, testes histomorphometry, gonadosomatic index (GSI), apoptotic gene expression, oxidative stress index, and sperm parameters were assessed. The results showed that DOX led to a significant decrease in histological indexes, testosterone level, GSI, sperm parameters, and Bcl-2 gene expression and increased expression of P-53 and Bax genes, and oxidative stress markers (P<0.05). The administration of ChV in the DOX+ChV group significantly improved testosterone levels, sperm parameters, testicular tissue apoptosis, antioxidant enzymes, and structural integrity of the testes (P<0.05). The findings suggest that the co-administration of ChV can be a promising therapeutic agent to reduce the adverse effects of DOX on male reproductive performance.

Immunoregulatory cyclophilin a improves low-dose chemotherapy with a modulation of the immune tumor microenvironment in experimental models of melanoma B16 and lymphoma EL4 in vivo

PURPOSE

Different regimens of low-dose chemotherapy (LDC) are currently being actively developed and introduced into clinical practice. Along with its obvious advantages compared to conventional chemotherapy (low toxicity, prevention of drug resistance), LDC could also stimulate anti-tumor immune responses in a patient by activating effectors of innate and adaptive immunity and diminishing tumor-associated immunosuppression. As non-myeloablative, LDC could be successfully combined with different anti-cancer immunotherapeutic strategies, including immunoregulatory cytokines. Secreted cyclophilin A (CypA) is of particular interest in this respect. Previously, we showed that recombinant human CypA (rhCypA) had pleiotropic immunostimulatory activity and anti-tumor effects. Thus, rhCypA could be potentially proposed as a perspective component of combined therapy with LDC.

METHODS

In this work, we evaluated the anti-tumor effects of rhCypA combined with low doses of cyclophosphamide, doxorubicin, dacarbazine, and paclitaxel in the experimental mouse tumor models of melanoma B16 and lymphoma EL4 in vivo.

RESULTS

Synergic and potentiating effects of rhCypA combined with LDC were shown in these studies. Furthermore, as a monotherapeutic agent and a component of combined chemoimmunotherapy, rhCypA was shown to modulate the immune tumor microenvironment by enhancing tumor infiltration with macrophages, NK cells, and T cells. It was also found that rhCypA stimulated both systemic and local anti-tumor immune responses.

CONCLUSION

RhCypA could be potentially proposed as a perspective component of the combined cancer chemoimmunotherapy.

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.