Zerrin Ozgen

Quercetin protects radiation-induced DNA damage and apoptosis in kidney and bladder tissues of rats

Abstract Ionizing radiation (IR) can induce cell damage and cell death through the reactive oxygen species generated by radiolytic hydrolysis. The present study was aimed to determine the possible protective effects of quercetin, a well-known antioxidant agent, against IR-induced bladder and kidney damage in rats. Sprague-Dawley rats were exposed to 8-Gy whole-abdominal IR and given either vehicle or quercetin (20 mg/kg, ip). Rats were decapitated at either 36 h or 10 days following IR, where quercetin or vehicle injections were repeated once daily, and kidney and bladder samples were obtained for the determination of myeloperoxidase and caspase-3 activities, an index of tissue neutrophil infiltration and apoptosis, respectively. Radiation-induced inflammation was evaluated through tissue cytokine, TNF-α levels. In order to examine oxidative DNA damage, tissue 8-hydroxydeoxyguanosine (8-OHdG) levels were measured. All tissues were also examined microscopically. In the saline-treated irradiation groups, myeloperoxidase and caspase-3 activities, 8-OHdG and TNF-α levels were found to be increased in both tissues (p < 0.05). In the quercetin-treated-IR groups, all these oxidant responses were prevented significantly (p < 0.05). The present data demonstrate that quercetin, through its free radical scavenging and antioxidant properties, attenuates irradiation-induced oxidative organ injury, suggesting that quercetin may have a potential benefit in radiotherapy by minimizing the adverse effects and will improve patient care.

Prognostic role of sensitive-to-apoptosis gene expression in rectal cancer

AIM To investigate the association between prognosis of rectal cancer treated with chemoradiotherapy (CRT) and expression of sensitive-to-apoptosis (SAG), B-cell lymphoma-extra large (Bcl-X(L)) and Bcl-2 homologous antagonist/killer (Bak). METHODS Real-time quantitative polymerase chain reaction was used to determine the expression of proteins of interest, namely SAG, Bcl-X(L), Bak and β-actin, in rectal carcinoma patients who had a follow-up period of 3 years after CRT. Biopsy specimens were excised from the rectal tumor preceding CRT. RESULTS SAG, Bcl-X(L) and Bak proteins showed significant correlations with each other. In multivariate analysis, patients with high vs low SAG expression showed a statistically significant difference in 2-year survival rates: 56% vs 73%, respectively (P = 0.056). On the other hand, there were no significant correlations between the expression levels of all three genes and metastatic rates or tumor responses to CRT. Mean overall survival in the patients with elevated SAG expression was 27.1 mo ± 3.9 mo [95% confidence interval (CI): 19.3-34.9], and in patients with reduced expression, it was 32.1 mo ± 2.5 mo (95% CI: 27.3-36.9). The corresponding values for Bcl-X(L) were 28.0 mo ± 4.1 mo (95% CI: 19.9-36.1) and 31.7 mo ± 2.9 mo (95% CI: 26.0-37.5), and those for Bak were 29.8 mo ± 3.7 mo (95% CI: 22.5-37.2) and 30.6 mo ± 2.4 mo (95% CI: 25.5-35.0), respectively. CONCLUSION Two-year survival rates significantly correlated with low SAG expression, and SAG may be a candidate gene for good prognosis, independent of therapeutic response of different individuals.

Investigation into the role of the cholinergic system in radiation-induced damage in the rat liver and ileum

It has been previously shown that acetylcholine (ACh) may affect pro-inflammatory and anti-inflammatory cytokines. The role of the cholinergic system in radiation-induced inflammatory responses and tissue damage remains unclear. Therefore, the present study was designed to determine the radio-protective properties of the cholinergic system in the ileum and the liver of rats. Rats were exposed to 8-Gy single-fraction whole-abdominal irradiation and were then decapitated at either 36 h or 10 d post-irradiation. The rats were treated either with intraperitoneal physiological saline (1 ml/kg), physostigmine (80 µg/kg) or atropine (50 μg/kg) twice daily for 36 h or 10 d. Cardiac blood samples and liver and ileal tissues were obtained in which TNF-α, IL-1β and IL-10 levels were assayed using ELISA. In the liver and ileal homogenates, caspase-3 immunoblots were performed and myeloperoxidase (MPO) activity was analyzed. Plasma levels of IL-1β and TNF-α increased significantly following radiation (P < 0.01 and P < 0.001, respectively) as compared with non-irradiated controls, and physostigmine treatment prevented the increase in the pro-inflammatory cytokines (P < 0.01 and P < 0.001, respectively). Plasma IL-10 levels were not found to be significantly changed following radiation, whereas physostigmine augmented IL-10 levels during the late phase (P < 0.01). In the liver and ileum homogenates, IL-1β and TNF-α levels were also elevated following radiation, and this effect was inhibited by physostigmine treatment but not by atropine. Similarly, physostigmine also reversed the changes in MPO activity and in the caspase-3 levels in the liver and ileum. Histological examination revealed related changes. Physostigmine experiments suggested that ACh has a radio-protective effect not involving the muscarinic receptors.

The association of apoptotic protein expressions sensitive to apoptosis gene, p73 and p53 with the prognosis of cervical carcinoma

Objective To evaluate the expressions of several apoptotic pathway proteins in relation to clinical parameters and survival in patients with cervical carcinoma. Methods A total of 20 patients with clinically advanced staged carcinoma of cervix (International Federation of Gynecology and Obstetrics [FIGO] stage IIB-IVA) aged from 40 to 75 years were included in this study. The expression profile of anti-apoptotic protein (sensitive to apoptosis gene [SAG]), mitochondrial apoptotic proteins (B-cell lymphoma-extra-large [Bcl-xL] and Bcl-2 homologous antagonist/killer [Bak]), and tumor suppressor proteins (p73 and p53) were examined by real-time polymerase chain reaction experiments along with their relation to clinical parameters and survival analyses during follow-up for 5 to 8 years. Results No significant difference was found in the expressions of SAG, Bcl-xL, Bak, p73 and p53 proteins with respect to stage and grade of tumor. A significant positive correlation was noted between SAG and Bcl-xL genes (r=0.752, P<0.001) and between SAG and Bak genes (r=0.589, P=0.006). Among genes determined to be significantly associated with overall survival in the univariate analysis (P=0.026 for SAG, P=0.002 for Bcl-xL, and P=0.027 for p53), only p53 was identified as the significant predictor in the multivariate analysis (hazard ratio: 8.53, 95% confidence interval: 1.34–54.2, P=0.023). Conclusion In conclusion, our findings demonstrated a reverse correlation of SAG, Bcl-xL, and p53 expressions with overall survival of patients. No association of apoptotic pathway proteins with clinicopathological characteristics of cervical carcinoma patients was noted. Low SAG, Bcl-xL, and p53 expression levels revealed to be useful as prognostic predictors in patients with cervical carcinoma.

Survival in gastric cancer in relation to postoperative adjuvant therapy and determinants

AIM To evaluate survival data in patients with gastric cancer in relation to postoperative adjuvant therapy and survival determinants METHODS A total of 201 patients (mean±SD age: 56.0±11.9 years, 69.7% were males) with gastric carcinoma who were operated and followed up at Lutfi Kirdar Kartal Training and Research Hospital between 1998 and 2010 were included in this retrospective study. Follow up was evaluated divided into two consecutive periods (before 2008 and 2008-2010, respectively) based on introduction of 3-D conformal technique in radiotherapy at our clinic in 2008. Data on patient demographics, clinical and histopathological characteristics of gastric carcinoma and the type of treatment applied after surgery [postoperative adjuvant treatment protocols including chemoradiotherapy (CRT) and chemotherapy (CT), supportive therapy or follow up without any treatment] were recorded. The median duration and determinants of local recurrence free (LRF) survival, distant metastasis free (DMF) survival and overall survival were evaluated in the overall population as well as with respect to follow up years [1998-2008 (n=127) vs 2008-2010 (n=74)]. RESULTS Median duration for LRF survival, DMF survival and overall survival were 31.9, 24.1 and 31.9 mo, respectively in patients with postoperative adjuvant CRT. No significant difference was noted in median duration for LRF survival, DMF survival and overall survival with respect to treatment protocols in the overall population and also with respect to followed up periods. In the overall population, CT protocols FUFA [5-fluorouracil (400 mg/m2) and leucovorin-folinic acid (FA, 20 mg/m2)] (29.9 mo) and UFT®+Antrex® [a fixed combination of the oral FU prodrug tegafur (flouroprymidine, FT, 300 mg/m2 per day) with FA (Antrex®), 15 mg tablet, two times a day] (42.5 mo) was significantly associated with longer LRF survival times than other CT protocols (P=0.036), while no difference was noted between CT protocols in terms of DMF survival and overall survival. Among patients received CRT, overall survival was significantly longer in patients with negative than positive surgical margin (27.7 mo vs 22.4 mo, P=0.016) in the overall study population, while time of radiotherapy initiation had no significant impact on survival times. Nodal stage was determined to be independent predictor of LRF survival in the overall study population with 4.959 fold (P=0.042) increase in mortality in patients with nodal stage N2 compared to patients with nodal stage N0, and independent predictor of overall survival with 5.132 fold (P=0.006), 5.263 fold (P=0.027) and 4.056 fold (P=0.009) increase in the mortality in patients with nodal stage N3a (before 2008), N3b (before 2008) and N2 (overall study population) when compared to patients with N0 stage, respectively. CONCLUSION Our findings emphasize the likelihood of postoperative adjuvant CRT to have a survival benefit in patients with resectable gastric carcinoma.

Challenges in the treatment of fibrodysplasia ossificans progressiva

Fibrodysplasia ossificans progressiva (FOP), is a rare autosomal dominant connective tissue disease with a prevalence of 1 in 2 million. It is characterized by congenital foot deformities and multiple heterotopic ossifications in fibrous tissue. It usually starts with painful soft tissue swellings occurring with attacks at the ages of three or four. The attacks develop spontaneously or after minor trauma, and gradually turn into heterotopic ossifications that cause joint limitations, growth defects, skeletal deformities and chronic pain. The average life expectancy is forthy, and most of the patients are lost due to pulmonary complications. FOP is often misdiagnosed as fibromatosis, desmoid tumour or cancer, bunion, myositis, arthritis and rheumatic diseases. After clinical suspicion, confirmatory genetic analysis should be used for the diagnosis. The treatment of FOP is currently supportive. An effective, proven method has not yet been established. Herein, we present an 18-year-old female patient with FOP who underwent different treatment modalities in a 5-year period. This case-based review reveals all available treatment approaches with at least 6-month follow-up for FOP in the literature.

Surgical Clips in Breast-conserving Surgery: Do They Represent the Tumor Bed Accurately?

INTRODUCTION Radiotherapy after Breast-Conserving Surgery (BCS) is a standard treatment for breast cancer. Currently, surgical clips are used to determine the tumour bed before radiotherapy planning. This study aimed to evaluate the migration of these clips on mammograms. METHODS The study was conducted on 121 females who were treated with radiotherapy after BCS at their first radiologic control examination 6 months after the end of treatment. MLO and CC views of all cases were evaluated regarding the clips. The distance between the surgical scar centre and the centre of the area covered by the clips was measured on both MLO and CC projections and recorded separately. This distance was determined as the clip displacement. A displacement ≤10 mm was recorded as no displacement. RESULTS The clips were out of the images and were not evaluated in 45 cases (37.2%) on CC and in 9 cases (7.4%) on MLO projections. There were no clip displacements in 37 (30.6%) cases on CC and in 43 (35.5%) cases on MLO views. The amount of displacement ranged from 11 to 56 mm with a mean of 24.38 mm on CC views, while on MLO projections, displacement ranged from 11 to 66 mm with a mean of 24.42 mm. CONCLUSION A clip displacement of greater than 10 mm was found in 64.5% of cases on MLO views. Therefore, we believe that the reliability of these clips for accurate delineation of the tumour bed in radiotherapy planning is controversial and other methods must be added.

Pre- and post-surgery treatments in rectal cancer: a long-term single-centre experience

BACKGROUND Our study evaluated long-term survival outcomes in rectal cancer patients treated with preoperative radiotherapy, and the impact on survival of concomitant and postoperative adjuvant chemotherapy (ctx), among other prognostic factors. METHODS The study included 196 patients [median age: 58 years (range: 20-86 years); 63.0% men] with locally advanced rectal carcinoma and, in some cases, resectable liver metastasis. Rates of distant metastasis and local recurrence and of 5-year distant metastasis-free survival (dmfs) and overall survival (os) were determined. RESULTS The 5-year os rate was 57.0%, with a median duration of 81.5 months (95% confidence interval: 73.7 months to 89.4 months), and the 5-year dmfs rate was 54.1%, with a median duration of 68.4 months (95% confidence interval: 40.4 months to 96.4 months). Prognostic factors for higher os and dmfs rates were downstaging (p = 0.013 and p = 0.005 respectively), radiotherapy dose (50 Gy vs. 56 Gy or 45-46 Gy, both p = 0.002), and concomitant ctx use (p = 0.004 and p = 0.001) and type (5-fluorouracil-leucovorin-folinic acid vs. tegafur-folinic acid, p = 0.034 and p = 0.043). Adjuvant ctx after neoadjuvant long-term concomitant chemoradiotherapy (ccrt) and surgery was associated with better 5-year os rates for postoperative T0-T3 disease (p = 0.003) and disease at all lymph node stages (p = 0.001). CONCLUSIONS Our findings revealed a favourable survival outcome with long-term fractionated irradiation and concomitant 5-fluorouracil-based ctx, achieving 5-year os and dmfs rates of 57.0% and 54.1% respectively. Preoperative administration of radiotherapy (50 Gy) and postoperative adjuvant ctx were associated with a significant survival benefit. Radiation doses above 50 Gy and the interval between ccrt and surgery had no significant effect on survival.

Functional and clinical evaluation of renal injury in patients treated with adjuvant chemoradiotherapy for gastric cancer: Low dose and comorbidity considerations

Abstract Aim To analyze the dosimetric factors affecting long-term renal function in patients with gastric cancer following postoperative radiotherapy with concomitant chemotherapy to the upper abdomen. Methods Between January 2005 and July 2010, 13 patients treated with three-dimensional conformal radiotherapy and concurrent fluorouracil-based chemotherapy (CRT) were included in this analysis. After a median follow-up of 55 months, creatinine, glomerular filtration rate (GFR), total kidney and left kidney volumes, before and after CRT and mercaptoacetyltriglycine (MAG3) scintigraphy, were used to evaluate the renal function and were correlated with the dosimetrics data. Results Significant correlations were found in the loss of left kidney volume and V35 (20.6%) (p = 0.035) and V40 (15.7%) (p = 0.031) and in the loss of relative functional contribution of the main kidney and V35 Gy (p = 0.027) and V40 Gy (p = 0.019). In patients with a slightly low basal GFR (n = 6), the relative functional contribution of the left kidney significantly decreased, regardless of the dosage. Conclusion Functional renal impairment without any clinical signs or symptoms can be observed in low doses after radiotherapy. Careful treatment planning and a detailed evaluation of the functional renal capacity before treatment may help to reduce late renal toxicity.

The effect of magnesium and vitamin E pre-treatments on irradiation-induced oxidative injury of cardiac and pulmonary tissues in rats: a randomized experimental study.

OBJECTIVE The aim of this study was to investigate the effect of pre-treatment with the free radical scavenging molecules, magnesium and vitamin E, on lipid peroxidation to limit radiation-induced heart and lung injury. METHODS Female Sprague-Dawley rats were divided into 4 groups by a simple randomization method as saline-treated control (n=4), saline-treated irradiated (IR; n=6), magnesium sulphate-treated irradiation (IR) (Mg+IR; n=6) and vitamin E-treated IR (vit E+IR; n=6), respectively. The animals were given either saline, Mg (600 mg/kg/day) or vit E (100 mg/kg/day) intraperitoneally for five days prior to irradiation. Twelve hours after the fifth injection, animals in irradiation groups were irradiated to 20 Gy using 6 MV photons in linear accelerator. Twenty-four hours later cardiac and lung tissue samples were obtained for determination of myeloperoxidase activity (MPO), malondialdehyde (MDA) levels, and luminol and lucigenin levels measured by chemiluminescence (CL) methods. RESULTS No significant changes were observed between cardiac and pulmonary MDA and CL results of the experimental groups. However, cardiac and pulmonary MPO activities in the saline-treated IR group were increased as compared to control group (p<0.05 for all), while in the Mg-pretreated and vit E pretreated groups neutrophil infiltration was reduced, reaching to statistical significance only in the Mg-pretreated group (p<0.05). CONCLUSION Prophylactic use of magnesium sulfate has limited the infiltration of neutrophils to both the cardiac and pulmonary tissues at the early 24 h of irradiation. However, how limiting neutrophils as the sources of free radicals and inflammatory mediators would alter oxidative stress of heart and lung tissues in the long-term is not clear yet.