Serum Oxidative Stress Markers and Genotoxic Profile Induced by Chemotherapy in Patients with Breast Cancer: A Pilot Study

The evaluation of the inflammatory status and systemic antioxidant-oxidant balance of women with breast cancer during adjuvant chemotherapy

Background

Chemotherapy may cause systemic inflammation. Therefore, reliable markers monitoring inflammation during cancer treatment are intensively investigated. In our study, we analyzed the concentration of high-sensitivity C-reactive protein (hs-CRP) and selected oxidative stress markers, such as malondialdehyde (MDA), glutathione peroxidase activity (GPx), and total antioxidant capacity (TAC), in breast cancer women before and during adjuvant chemotherapy.

Materials and methods

The study included 90 women with breast cancer stratified according to clinicopathological and anthropometric features. Blood samples were taken before and after two cycles of adjuvant chemotherapy.

Results

During adjuvant chemotherapy, a significant increase in hs-CRP concentration was noticed in the entire group of patients with breast cancer. After division into appropriate groups, a twofold increase in hs-CRP concentration was particularly observed in patients not expressing steroid hormone receptors and those without metastases in regional lymph nodes. A significant rise in hs-CRP was observed in patients with smaller tumor sizes (2 cm ≤) and with a lower stage of disease [I-IIA according to the tumor-node-metastasis (TNM) classification]. Adjuvant chemotherapy resulted in a significant decrease in GPx activity, especially in patients diagnosed with larger (> 2 cm) and more advanced tumors (IIB-IIIC according to the TNM classification), without metastasis in regional lymph nodes, and without HER-2 expression. A significant decrease in glutathione peroxidase (GPx) activity during adjuvant chemotherapy was also observed in patients with abnormal body mass index (BMI) and body fat content. TAC and MDA values remained unchanged in the entire group of patients and individual subgroups during adjuvant chemotherapy.

Conclusion

Our study showed that adjuvant chemotherapy causes systemic inflammation, manifested by increased hs-CRP and altered markers of oxidative stress in the blood of breast cancer patients. The severity of inflammatory processes during adjuvant chemotherapy may depend on specific characteristics of breast cancer and body composition.

Octyl Gallate and Gallic Acid Isolated from Terminalia bellirica Circumvent Breast Cancer Progression by Enhancing the Intrinsic Apoptotic Signaling Pathway and Elevating the Levels of Anti-oxidant Enzymes

Exploration of new strategies and identification of less expensive novel chemoprevention agents against breast cancer progression have become the need of the hour. Thus, the present study aimed at evaluating the anti-cancer efficacies of octyl gallate (OG) and gallic acid (GA) isolated from Terminalia bellirica (T. bellirica) in breast cancer cell lines and DMBA-induced Sprague-Dawley animal model. The results of western blot analysis show significant (p < 0.05) downregulation of anti-apoptotic protein (Bcl-2 and Bcl-xL) expression and up-regulation of pro-apoptotic protein (Bak and Bax) expression in both MCF-7 and MDA-MB-231 cell lines. Our findings also show that DMBA-induced Sprague-Dawley rats (50-55 days old) orally administered with OG (20 mg/kg body wt.) and GA (20 mg/kg body wt.) for a treatment period of 14 weeks were observed for normalized body weight changes and hematological indices and significant reduction of tumor markers carcinoembryonic antigen (CEA), cancer antigen 15.3 (CA 15.3), and oxidative stress (TBARS) in serum, while the activity of anti-oxidant enzyme (SOD, CAT, and GPx) levels estimated in the mammary tissue was found restored back to normal. Computational molecular interaction study was also performed to substantiate the in vitro obtained results. The tissue histology reveals the therapeutic role of OG and GA. The study conducted brings to limelight of the molecular mechanisms of intrinsic apoptotic signaling pathway through which OG and GA exert their chemopreventive action. Both OG and GA can be explored further as chemotherapeutic natural drugs for their ability to prevent breast cancer progression.

Non-clinical toxicity of (+)-limonene epoxide and its physio-pharmacological properties on neurological disorders

The compound (+)-limonene epoxide has antioxidant, anxiolytic, and antihelminthic properties. However, investigations to determine its long-term exposure were not performed. We investigated the systemic toxicological profile after chronic exposure as well as the antidepressant and antiepileptic potentialities of (+)-limonene epoxide on mice. Initially, we evaluated acute toxicity on Artemia salina nauplii and cytotoxicity on mice erythrocytes and peripheral blood mononuclear cells (PBMC). Aftterwards, mice were chronically treated for 120 days by gavage with (+)-limonene epoxide (25, 50, and 75 mg/kg/day) and this exposure was assessed by pathophysiological measurements. For antidepressant and anticonvulsivant analysis, we performed the forced swimming and tail suspension protocols and pentylenetetrazol- and picrotoxin-induced seizures, respectively. (+)-Limonene epoxide showed a LC50 value of 318.7 μg/mL on A. salina shrimps, caused lysis of red blood cells at higher concentrations only but did not show cytotoxicity on PMBC, which suggests pharmacological safety if plasma concentrations do not exceed 100 μg/mL. Macroscopic, hematological, clinical chemistry, and nutritional changes were not detected, though focal areas of hepatic necrosis, inflammatory infiltrate, and karyolysis have been detected at 75 mg/kg/day. The compound inhibited the developing of pentylenetetrazol- and picrotoxin-induced seizures, decreased deaths, and reduced immobility times, mainly at 75 mg/kg. So, it reversed reserpine effects, suggesting antidepressant effects should be linked to serotonergic and/or adrenergic transmission. It is feasible that (+)-limonene epoxide plays a benzodiazepine-like anticonvulsive action and may be also recommended as an antidote for poisonings caused by central depressants.

Hydroxytyrosol Supplementation Modifies Plasma Levels of Tissue Inhibitor of Metallopeptidase 1 in Women with Breast Cancer

The etiology of breast cancer can be very different. Most antineoplastic drugs are not selective against tumor cells and also affect normal cells, leading to a wide variety of adverse reactions such as the production of free radicals by altering the redox state of the organisms. Therefore, the objective of this study was to elucidate if hydroxytyrosol (HT) (an antioxidant present in extra virgin olive oil) has a chemomodulatory effect when combined with the chemotherapeutic drugs epirubicin and cyclophosphamide followed by taxanes in breast cancer patients. Changes in plasma levels of matrix metalloproteinase 9 (MMP-9) and tissue inhibitor of metalloproteinases 1 (TIMP-1) throughout the chemotherapy treatment were studied. Both molecules are involved in cell proliferation, apoptosis, neoangiogenesis, and metastasis in breast cancer patients. Women with breast cancer were divided into two groups: a group of patients receiving a dietary supplement of HT and a control group of patients receiving placebo. The results showed that the plasma levels of TIMP-1 in the group of patients receiving HT were significantly lower than those levels found in the control group after the epirubicin-cyclophosphamide chemotherapy.

The conundrum of dietary antioxidants in cancer chemotherapy

Although chemotherapy succeeds in reducing tumor burden, the efficacy is limited due to acquired drug resistance and often irreparable side effects. Studies show that antioxidants may influence the response to chemotherapy and its side effects, although their use remains controversial. The evidence shows that some chemo-drugs induce oxidative stress and lead to normal tissue apoptosis and the entry of cancer cells to a dormant G0 state. Through the suppression of oxidative stress, antioxidants could protect normal cells and bring the tumor out of dormancy so as to expose it to chemotherapies. This review is focused on the redox biology of cancer/normal cells and association of reactive oxygen species with drug resistance, cancer dormancy, and side effects. To this end, evidence from cellular, animal, and clinical studies is provided to better understand the conundrum of dietary antioxidants in cancer chemotherapy.

Effect of Diets, Familial History, and Alternative Therapies on Genomic Instability of Breast Cancer Patients

This study evaluates a correlation between family history, micronutrients intake, and alternative therapies with genetic instability, before and during breast cancer treatment. For this study, a total of 150 women were selected. Among those, 50 women were breast cancer patients on chemotherapy, while 50 breast cancer patients were on radiotherapy, and 50 were healthy females. All the participants signed the informed consent form and answered the public health questionnaire. Samples of buccal epithelial and peripheral blood cells were collected and analyzed through micronucleus and comet assays. The cells were evaluated for apoptosis and DNA damage. Results showed the association of patients' family history with an increase in toxicogenetic damage before and during cancer therapy. On the other hand, patients with late-onset cancer also presented genetic instability before and during therapy, along with those who did not take sufficient vegetables and alternative therapies. A positive correlation was observed between the genetic instability and alternative therapies, while inverse correlation was recorded with the vegetable consumption. Results clearly explain that the nutritional aspects and alternative therapies influence the genetic instability before and during cancer therapies especially in radiotherapy treated patients. Our data could be used for the monitoring therapies and management of breast cancer patients.

Persistent Increased Frequency of Genomic Instability in Women Diagnosed with Breast Cancer: Before, during, and after Treatments

This study aimed to evaluate DNA damage in patients with breast cancer before treatment (background) and after chemotherapy (QT) and radiotherapy (RT) treatment using the Comet assay in peripheral blood and the micronucleus test in buccal cells. We also evaluated repair of DNA damage after the end of RT, as well as the response of patient's cells before treatment with an oxidizing agent (H2O2; challenge assay). Fifty women with a mammographic diagnosis negative for cancer (control group) and 100 women with a diagnosis of breast cancer (followed up during the treatment) were involved in this study. The significant DNA damage was observed by increasing in the index and frequency of damage along with the increasing of the frequency of micronuclei in peripheral blood and cells of the buccal mucosa, respectively. Despite the variability of the responses of breast cancer patients, the individuals presented lesions on the DNA, detected by the Comet assay and micronucleus Test, from the diagnosis until the end of the oncological treatment and were more susceptible to oxidative stress. We can conclude that the damages were due to clastogenic and/or aneugenic effects related to the neoplasia itself and that they increased, especially after RT.

Blood and Tissue Enzymatic Activities of GDH and LDH, Index of Glutathione, and Oxidative Stress among Breast Cancer Patients Attending Referral Hospitals of Addis Ababa, Ethiopia: Hospital-Based Comparative Cross-Sectional Study

The exact cause of breast cancer is unknown; it is a multifactorial disease. It is the most diagnosed and the second killer cancer among women. Breast cancer can be originated from tissues of breast or secondary from other organs via metastasis. Generally, cancer cells show aberrant metabolism and oxidative stress when compared to noncancerous tissues of breast cancer patients. The current study aims at evaluating glutamate and glucose metabolism through GDH and LDH enzyme activities, oxidant, and antioxidative status among breast cancer patients attending referral hospitals of Addis Ababa, Ethiopia. Result. Catalytic activities of glutamate dehydrogenase, lactate dehydrogenase, and oxidative stress index were significantly increased in both serum (4.2 mU/ml, 78.6 mU/ml, and 3.3 : 1, resp.) and cancerous tissues (1.4 mU/ml, 111.7 mU/ml, and 2.15 : 1, resp.) of breast cancer patients as compared to those in serum of control group (3.15 mU/ml, 30.4 mU/ml, and 2.05 : 1, resp.) and noncancerous tissues of breast cancer patients (0.92 mU/ml, 70.5 mU/ml, and 1.1 : 1, resp.) (P ≤ 0.05). Correspondingly, ratios of reduced to oxidized glutathione were significantly decreased in both serum (20 : 1) and cancerous tissues (23.5 : 1) of breast cancer patients when compared to those in serum of control group (104.5 : 1) and noncancerous tissues of breast cancer patients (70.9 : 1) (P ≤ 0.05). Conclusion. Catalytic activities of GDH and LDH, ratios of GSH to GSSG, and concentration of TOS among breast cancer patients were significantly higher than were those among control group and noncancerous tissues of breast cancer patients, while TAC of breast cancer patients is significantly lower than that of control group and normal tissues of breast cancer patients.