Vanessa Jacob Victorino

Differential oxidative status and immune characterization of the early and advanced stages of human breast cancer

Breast cancer is the malignant neoplasia with the highest incidence in women worldwide. Chronic oxidative stress and inflammation have been indicated as major mediators during carcinogenesis and cancer progression. Human studies have not considered the complexity of tumor biology during the stages of cancer advance, limiting their clinical application. The purpose of this study was to characterize systemic oxidative stress and immune response parameters in early (ED; TNM I and II) and advanced disease (AD; TNM III and IV) of patients diagnosed with infiltrative ductal carcinoma breast cancer. Oxidative stress parameters were evaluated by plasmatic lipoperoxidation, carbonyl content, thiobarbituric reactive substances (TBARS), nitric oxide levels (NO), total radical antioxidant parameter (TRAP), superoxide dismutase, and catalase activities and GSH levels. Immune evaluation was determined by TNF-α, IL-1β, IL-12, and IL-10 levels and leukocytes oxidative burst evaluation by chemiluminescence. Tissue damage analysis included heart (total CK and CKMB), liver (AST, ALT, GGT), and renal (creatinine, urea, and uric acid) plasmatic markers. C-reactive protein (CRP) and iron metabolism were also evaluated. Analysis of the results verified different oxidative stress statuses occur at distinct cancer stages. ED was characterized by reduction in catalase, 8-isoprostanes, and GSH levels, with enhanced lipid peroxidation and TBARS levels. AD exhibited more pronounced oxidative status, with reduction in catalase activity and TRAP, intense lipid peroxidation and high levels of NO, TBARs, and carbonyl content. ED patients presented a Th2 immune pattern, while AD exhibited Th1 status. CRP levels and ferritin were increased in both stages of disease. Leukocytes burst impairment was observed in both the groups. Plasma iron levels were significantly elevated in AD. The data obtained indicated that oxidative stress enhancement and immune response impairment may be necessary to ensure cancer progression to advanced stages and may result from both host and tumor inflammatory mediators.

Molecular subtype is determinant on inflammatory status and immunological profile from invasive breast cancer patients

Breast cancer consists in a chronic inflammatory disease with multiple biological and clinical behaviors. Based on high throughput technologies data, this disease is currently classified according to the molecular expression of estrogen (ER), progesterone (PR) and human epidermal growth factor (HER-2) receptors. In this study, we defined the inflammatory profile of the main molecular subtypes of breast cancer patients: luminal (ER and PR positive, HER-2 negative), HER-2 enriched (HER-2 positive) and triple negative (ER, PR and HER-2 negative). Cytokines panel was assessed by measurement of TNF-α, TGF-β, IL-1, IL-10 and IL-12 plasmatic levels. Oxidative profile was assessed by determination of lipid peroxidation, total antioxidant capacity of plasma, malondialdehyde levels, carbonyl content and nitric oxide (NO). Clinical data were correlated with inflammatory findings. Our findings demonstrated that patients bearing the luminal subtype displayed high TNF-α, TGF-β and enhanced oxidative stress levels associated with reduced IL-12. HER-2-enriched group exhibited higher levels of TNF-α, IL-12 and TGF-β associated with enhanced oxidative stress. Triple-negative subtype exhibited the most aggressive profile of disease behavior, with reduction in both TNF-α and TGF-β, with high levels of lipid peroxidation and NO. The clinical importance of our findings lies in the fact that the inflammatory status varies in distinct ways due to molecular subtype of breast cancer, opening potential therapeutic targets to future therapies.

Systemic toxicity induced by paclitaxel in vivo is associated with the solvent cremophor EL through oxidative stress-driven mechanisms.

The toxic effects of paclitaxel (PTX) and its solubilizing agent cremophor EL (CREL) have been well established in vitro; however, the in vivo mechanisms underlying this toxicity remain unclear. Thus, the aim of this study was to analyze the in vivo toxicity induced by infusion of PTX and CREL and to investigate the involvement of oxidative stress as a potential mechanism for this toxicity. We treated male Wistar rats with PTX and/or CREL for 1h using human-equivalent doses (PTX+CREL/ethanol+NaCl 175mg/m(2) or CREL+ethanol+NaCl) and sacrificed immediately or 24h after these drug infusions to systemic biochemical evaluations. Hidrosoluble vitamin E (vitE, Trolox) was added as a control in some groups. The oxidative profile was determined by measuring erythrocyte and plasma lipid peroxidation, superoxide dismutase and catalase activities, reduced glutathione (GSH) levels, red blood cell (RBC) counts, hemoglobin profile, plasma total radical-trapping antioxidant parameter (TRAP), plasma lipid peroxidation, nitric oxide levels and malondialdehyde levels. Our findings showed that CREL infusion triggered immediate high plasma lipid peroxidation and augmented TRAP, while PTX caused immediate TRAP consumption and metahemoglobin formation. Pronounced oxidative effects were detected 24h after infusion, when CREL treatment enhanced RBC counts and plasma lipid peroxidation, increased catalase activity, and decreased TRAP levels. On the other hand, after 24h, PTX-infused rats showed reduced catalase activity and reduced metahemoglobin levels. These data indicate the existence of a continuous oxidative stress generation during CREL-PTX treatment and highlight CREL as primarily responsible for the in vivo oxidative damage to RBCs.

Immunological effects of Taxol and Adryamicin in breast cancer patients

Antineoplastic chemotherapy still consists in the major first-line therapeutics against cancer. Several reports have described the immunomodulatory effects of these drugs based on in vitro treatment, but no previous data are known about these effects in patients and its association with immunological-mediated toxicity. In this study, we first characterize the immunological profile of advanced breast cancer patients treated with doxorubicin and paclitaxel protocols, immediately after chemotherapy infusion. Our findings included an immediate plasmatic reduction in IL-1, IL-10, and TNF-α levels in doxorubicin-treated patients, as well as high levels of IL-10 in paclitaxel patients. Further, it was demonstrated that both drugs led to leukocytes oxidative burst impairment. In vitro analysis was performed exposing healthy blood to both chemotherapics in the same concentration and time of exposition of patients, resulting in low IL-10 and high IL-1β in doxorubicin exposition, as low TNF-α and high IL-1 in paclitaxel treatment. Nitric oxide levels were not altered in both in vivo and in vitro treatments. In conclusion, our data revealed for the first time that the immediate effects of chemotherapy could be mediated by cytokines signaling in patients and that the results observed in patients could be a resultant of host immune cells activation.

Oxidative stress, redox signaling and cancer chemoresistance: putting together the pieces of the puzzle.

Chemotherapy continues to be the main treatment option for cancer. Although systemic chemotherapy can efficiently eradicate cancer cells, a significant proportion of patients carry tumors that present a chemoresistant phenotype, resulting in disease progression, cancer relapse, and reduced survival. It has also become clear that the effect of most chemotherapeutic drugs is associated with their capacity to generate reactive species (RS) that bind to specific structures within the cancer cell and promote cell death. Due to repeated exposure to chemotherapeutic agents, the redox homeostasis of cancer cells is continuously disturbed, which can result in changes to the cells ability to cope with excessive RS levels through the production of protective molecules. It is thought that the imbalance resulting from this process-- oxidative stress--is toxic to cancer cells. Paradoxically, the metabolites produced during oxidative stress can favor the survival of some cancer subpopulations, which present specific gene signatures that confer a chemoresistant phenotype on these clones. Despite the huge amount of information generated by currently available technologies, we cannot predict whether this resistance will arise during chemotherapy and we still do not fully understand the mechanism by which it arises. In this review, we discuss the main findings regarding the role of oxidative stress signaling in cancer chemotherapy and the key redox molecules and pathways that lead to the development of chemoresistance.

Breast cancer in Brazil: epidemiology and treatment challenges.

Notwithstanding the advances in tumor research, diagnosis, and treatment, breast cancer is still a challenge worldwide. This global burden of disease has been associated with population aging and the persistence of cancer-related behaviors. The number of women diagnosed with breast cancer has been estimated as increasing, especially in middle-income countries such as Brazil. Estimates from the Instituto Nacional de Câncer (INCA) point to breast cancer as the major malignant neoplasia in Brazilian women and the main cause of death from cancer in the country. This fact has been associated with increased life expectancy, urbanization, and cancer-related behaviors. Given this scenario, it is clear that there is a need for identifying and discussing which factors have substantially contributed to this growing number of cases in Brazil, including access to treatment, prevention and early diagnosis, weaknesses of the local health policy, and intrinsic genetic peculiarities of the Brazilian population. This review aims to address the role of such factors.

Trastuzumab-based chemotherapy modulates systemic redox homeostasis in women with HER2-positive breast cancer

Trastuzumab is an immunotargeting therapeutic against breast tumors with amplification of the human epithelial growth factor receptor 2 (HER2). HER2 patients naturally exhibit disruption in the pro-oxidant inflammatory profiling; however, the impact of trastuzumab-based chemotherapy in modulating this process is still unknown. Here we determined the systemic pro-inflammatory profile of women diagnosed with HER2-amplified tumors, undergoing trastuzumab-based chemotherapy (TZ), and compared the results with that of healthy controls (CTR) and untreated patients with HER2-amplified breast cancer (CA). The plasmatic inflammatory profile was assessed by evaluating pro-oxidant parameters such as lipid peroxidation, total antioxidant capacity (TRAP), levels of advanced oxidation protein products (AOPPs), nitric oxide (NO), C-reactive protein (CRP), and total thiol content. Markers of cardiac damage were also assessed. Our findings showed increased NO levels in TZ than that in either CA or CTR groups. Furthermore, TZ augmented TRAP and reduced total thiol than that of the CA group. Our data also revealed that AOPP levels were significantly higher in the TZ than the CA group. AOPP and the MB fraction of creatine-kinase (CKMB) levels were positively correlated in TZ patients. These findings suggest that trastuzumab-associated chemotherapy can modulate the pro-inflammatory markers of HER2-positive breast cancer patients to the levels found in healthy controls.

Can Breast Tumors Affect the Oxidative Status of the Surrounding Environment? A Comparative Analysis among Cancerous Breast, Mammary Adjacent Tissue, and Plasma

In this paper, we investigated the oxidative profile of breast tumors in comparison with their normal adjacent breast tissue. Our study indicates that breast tumors present enhanced oxidative/nitrosative stress, with concomitant augmented antioxidant capacity when compared to the adjacent normal breast. These data indicate that breast cancers may be responsible for the induction of a prooxidant environment in the mammary gland, in association with enhanced TNF-α and nitric oxide.

Redox-Driven Events in the Human Immunodeficiency Virus Type 1 (HIV-1) Infection and their Clinical Implications

Oxidative stress is a condition characterized by the imbalance between the production of reactive species (RS) or free radicals and their neutralization by the antioxidant defenses, leading to the accumulation of RS and their derived metabolites, with changes in the redox status of the cell. These RS can act on biological components and induce the oxidative and nitrosative reactions on lipids, proteins, and DNA. In this context, a wide variety of chronic diseases present oxidative stress as a part of the pathogenesis, including the human immunodeficiency virus type 1 (HIV-1) infection. The relationship between oxidative stress and HIV-1 infection lies in the fact that the RS species are important components of the innate immune response, and their derived metabolites and reactions participate in several events of the adaptative immune response. On the other hand, studies have shown specific roles for oxidative-driven events in both the host immunity and the virus biology. Undoubtedly, the occurrence of oxidative stress in HIV-1-infected patients has been implicated in disease progression, as well as in developing other secondary disorders, such as cardiovascular diseases, insulin resistance, and metabolic syndrome. This review aims to characterize the redox-driven events in the HIV-1 infection and their clinical implications in the disease features.

Clinical insights from adiponectin analysis in breast cancer patients reveal its anti-inflammatory properties in non-obese women

Adiponectin is a cytokine reported as a determinant of poor prognosis in women with breast cancer. However, because data regarding its role in breast cancer have been obtained primarily from studies employing overweight or obese women, the adiponectin profile in non-obese women is poorly understood. In this study, we determined adiponectin levels in plasma from non-obese women with breast cancer and investigated a possible correlation with systemic inflammatory status. We determined the plasma adiponectin levels as well as biochemical and oxidative stress parameters in 80 women. Our results revealed that plasma adiponectin levels were affected by chemotherapy, estrogen receptor status, and disease progression. Adiponectin was positively correlated with antioxidant levels, without affecting either the metastatic behavior of disease or patient outcome. These findings highlight adiponectin as a novel player in the endocrine signaling that modulates the oxidative inflammatory response in human breast cancer, and contribute to the understanding of the role of adiponectin in pathological conditions in non-obese women.