Modification of 10 cGy neutron or gamma-rays induced chromosomal damages by hyperthermia: an in vitro study

Background: To evaluate the effects of hyperthermia (HT) on the frequency of chromosomal aberrations induced by a low dose of neutron or Y-rays in human peripheral blood lymphocytes. Materials and Methods: Blood samples were exposed to HT (41.5 degrees C for 30 and 60min, 43 degrees C for 15 and 30min), 10 cGy neutron or Y-rays, HT + neutron/Y, and neutron/Y + HT. After standard cell culture, harvesting, fixation and staining, the chromosomal damages were scored in metaphase plates. Results: HT alone at 41.5 degrees C did not induce chromatid or chromosome aberrations, however, the frequency of damages was significantly higher at 43 C (P<0.05). Furthermore, the chromosomal damages was significantly different when cells were irradiated with neutron or Y-rays alone (P<0.01). HT 1 hr post neutron/Y irradiation significantly induced higher chromosome damages in comparison to HT 1 hr before irradiation (P<0.05). The chromosomal damages were remarkably higher when cells were irradiated with neutron then heated at 43 C for 30 min. Conclusion: Since increasing frequency of chromosome damages increases probability of cell death, application of HT after neutron irradiation (instead of X- or gamma- rays) might be considered as a procedure for cells killing in radiotherapy. Iran. J. Radiat. Res., 2009; 7 (2): 69-7

The Effect of miR-372 on Genome Instability in MKN-45 Cell Line

Background: Gastric cancer is one of the most common cancers in the world and the second leading cause of cancer mortality in humans. MicroRNAs are a group of endogenous RNA, small non-coding nucleotides in length of 21-23. Overexpression of miR-372 acts as an oncomir in various types of cancer via down-regulation of its target, LATS2. Down-regulation of LATS2 leads to the loss of cell cycle regulation, apoptosis inhibition, and increased proliferation rate of the cells. Methods: In this study, we increased the expression of miR-372 with lentivirus transduction inside the GC cell line MKN-45. After selection of positive cells, miR-372 and LATS2 expression levels were measured through real-time polymerase chain reaction (RT-PCR) assay. Cytochalasin B blocked (MN) assay was done to verify the presence or absence of MN for comparing genomic instability in treated cells compared to the controls. Findings: In the treated cells, compared with the controls, the amount of miR-372 expression significantly increased. Fold changes in 7, 14 and 21 days after the transduction were 7.85, 50.22 and 114.68, respectively (P = 0.030). In contrast to the control cells, the fold changes of LATS2 expression in these days were 0.39, 0.29 and 0.15, respectively (P = 0. 016). In addition, compared with control cells, the genomic instability of treated cells increased significantly (P < 0.001). Conclusion: These results indicate that in MKN-45 cell line, LATS2 is a target of miR-372. LATS2 is down-regulated with increased expression of miR-372. Reduce LATS2, leads to genomic instability during cell division and creates micronuclei and hence may be an important tumor suppressor

Relationship study of the verified human epidermal growth factor receptor 2 amplification with other tumor markers and clinicohistopathological characteristics in patients with invasive breast cancer, using chromogenic in situ hybridization

Objective: Human epidermal growth factor receptor 2 (HER-2), as a crucial factor involved in about 20 of breast cancer cases, is one of the most reliable tumor markers to determine prognosis and therapeutic trend of this disease. This marker is generally assessed by immunohistochemistry (IHC) technique. In the cases that result of IHC test cast doubt (+2), the test should be repeated or validated by applying in situ hybridization techniques, like chromogenic in situ hybridization (CISH). In this regard, the goal of current study was to figure out the link between different clinicopathological characteristics of patients suffering from invasive breast cancer, using tumor markers, hormone receptor (HR) and HER-2. Comparing IHC and CISH techniques for evaluating diagnostic value and usefulness of HER-2 were also the other objective of this study. Materials and Methods: Based on this retrospective study, histological markers of 113 individuals suffering from invasive breast cancer -such as estrogen receptor (ER), progesterone receptor, HER-2 receptor, E-cadherin, CK5/6, vimentin and Ki67 were examined by IHC technique. HER-2 amplification of all patients was also evaluated by CISH. Clinicopathological information of the patients was also extracted from medical documents and their associations with tumor markers were statistically evaluated. Results: There is a significant relationship between tumor size, CK5/6 and tumor grade with HR status. Similar relationship was observed between HER-2 status and HR status, as well as vascular invasion (P<0.05). The comparison of HER-2 amplification showed no complete concordance of the result obtained from these two techniques, with score +3. Conclusion: Since the status of HER-2 is very important in decision making of the treatment process, CISH technique is recommended in the malignant conditions as the primary test, instead of IHC. In this study, we also determined that HER-2 expression is greatly correlated with ER- and PR- status. This might propose a better prognosis for HER-2+ patients. © 2019 Royan Institute (ACECR). All rights reserved

Role of circ-FOXO3 and miR-23a in radiosensitivity of breast cancer

Identifying the radiosensitivity of cells before radiotherapy (RT) in breast cancer (BC) patients allows appropriate switching between routinely used treatment regimens and reduces adverse side effects in exposed patients. In this study, blood was collected from 60 women diagnosed with Invasive Ductal Carcinoma (IDC) BC and 20 healthy women. To predict cellular radiosensitivity, a standard G2-chromosomal assay was performed. From these 60 samples, 20 BC patients were found to be radiosensitive based on the G2 assay. Therefore, molecular studies were finally performed on two equal groups (20 samples each) of patients with and without cellular radiosensitivity. QPCR was performed to examine the expression levels of circ-FOXO3 and miR-23a in peripheral blood mononuclear cells (PBMCs) and RNA sensitivity and specificity were determined by plotting Receiver Operating Characteristic (ROC) curves. Binary logistic regression was performed to identify RNA involvement in BC and cellular radiosensitivity (CR) in BC patients. Meanwhile, qPCR was used to compare differential RNA expression in the radiosensitive MCF-7 and radioresistant MDA-MB-231 cell lines. An annexin -V FITC/PI binding assay was used to measure cell apoptosis 24 and 48 h after 2 Gy, 4 Gy, and 8 Gy gamma-irradiation. Results indicated that circ-FOXO3 was downregulated and miR-23a was upregulated in BC patients. RNA expression levels were directly associated with CR. Cell line results showed that circ-FOXO3 overexpression induced apoptosis in the MCF-7 cell line and miR-23a overexpression inhibited apoptosis in the MDA-MB-231 cell line. Evaluation of the ROC curves revealed that both RNAs had acceptable specificity and sensitivity in predicting CR in BC patients. Binary logistic regression showed that both RNAs were also successful in predicting breast cancer. Although only circ-FOXO3 has been shown to predict CR in BC patients, circ-FOXO3 may function as a tumor suppressor and miR-23a may function as oncomiR in BC. Circ-FOXO3 and miR-23a may be promising potential biomarkers for BC prediction. Furthermore, Circ-FOXO3 could be a potential biomarker for predicting CR in BC patients.</p

Effects of famotidine and vitamin C on low dose radiation-induced micronuclei in mice bone marrow cells

     The radioprotective effects of vitamin C and famotidine were investigated using the micronucleus test for anticlastogenic and cell proliferation activity. Various doses of vitamin C and famotidine were administered intraperitoneally 2 h before 2Gy gamma irradiation to NMRI adult male mice. Frequency of micronuclei in 1000 PCEs (MnPCEs) were scored for each sample. Cell proliferation ratio (PCE/PCE+NCE) was also calculated. Data were statistically evaluated using one-way ANOVA and Tukey’s HSD test. The results indicated that gamma irradiation alone caused a significant increase in the MnPCEs and reduced the cell proliferation ratio. Administration of various doses of famotidine and vitamin C before gamma irradiation reduced MnPCEs and therefore clastogenic effects of radiation. Famotidine didn’t change cell proliferation compared to the irradiation group but vitamin C significantly improved and increased cell proliferation to the control group’s level. The dose reduction factor (DRF) calculated, shows a DRF=2 for famotidine and a DRF=1.7 for vitamin C which is indicative of a high radioprotective property of these compounds. The way in which these compounds reduced the clastogenic effects of radiation might be via antioxidant property and free radical scavenging mechanism

The probability of influence of the abscopal effect on reduction of similar far away 4T1 cell line tumors by irradiation of main tumor

The most important problem with radiotherapy is the limitation of whole body irradiation of a metastatic patient. There are evidence showing that similar effect will occur in non-irradiated tumors similar to the irradiated ones. This effect is called abscopal effect. In the present study, the abscopal effect on local induced mice breast cancers has been investigated. One million of 4T1 mice breast cancer cell line was injected to balb/c mice subcutaneously while being under anesthesia. After the growth of tumors till becoming palpable, one of two induced tumors were exposed to total 28 Gy, with gamma rays emitted from a cobalt -60 tele-therapy machine in 14 fractions with 2 Gy daily doses. Tumor volumes were measured, using the caliper. The data was analyzed by the use of non-parametrical and ANOVA tests. Similar growth in non-irradiated control tumors was seen. After 10 or 11 fractions of one- side irradiation and total dose of 20 to 22 Gy, however, non-irradiated tumors, similar to irradiated ones, showed similar effect, reduction of size and volume different from control groups (P&lt;0.05).The reduction of non-irradiated tumors relative to irradiation of another tumor in the same mouse is the emblem of occurrence of the abscopal effect. The mechanism of the abscopal effect is unknown but it could be related to the release of cytokines from irradiated tumors with their receptors existing on the surface of non-irradiated tumors. By induction of this effect, the remission probability of small metastases after local irradiation could be possible

Potent radioprotective effect of therapeutic doses of ranitidine and famotidine against gamma-rays induced micronuclei in vivo

ABSTRACT Background: Previous investigations have revealed, cimetidine, a histamine H2-receptor antagonist, show radioprotective effects against gamma-and neutron-induced micronuclei in bone marrow erythrocytes. In this study, the anticlastogenic effects of famotidine and ranitidine, which act similar to cimetidine as histamine H2-receptor antagonists, was investigated. Materials and Methods: Balb/c male mice were injected i.p. with various doses of famotidine and ranitidine two hours before 2 Gy gamma irradiation. Frequency of micronuclei was determined in bone marrow erythrocytes following each treatment. Results: The results indicated that gamma irradiation alone can cause a high frequency of micronuclei formation and decrease cell proliferation ratio. Pre-irradiation injection of famotidine and ranitidine, of various doses, effectively reduced the number of micronucleated polychromatic erythrocytes (MnPCEs), yet has no effect on cell proliferation ratio (PCEs/PCEs+NCEs). In fact, these two drugs reduce the clastogenic effects of gamma rays, while they are ineffective against the cytotoxic properties of gamma rays

Association of elevated frequency of micronuclei in peripheral blood lymphocytes of type 2 diabetes patients with nephropathy complications

The increasing incidence of type 2 diabetes mellitus globally has increased the incidence of diabetes-associated complications such as nephropathy. DNA damage induced by oxidative stress might be one of the important mechanisms in the pathogenesis of diabetic complications. Two hundred Iranian individuals with the conditions of type 2 diabetes, diabetic nephropathy and nephropathy patients with no sign of diabetes and normal unaffected sex- and age-matched controls (50 in each group) were enrolled in the study. The background and the net levels of micronucleus (MN) formation as well as other cellular damages induced after in vitro treatment with 25 μg/ml of bleomycin (BLM) were evaluated using cytokinesis block MNs cytome assay (CBMN cyt) in peripheral blood lymphocytes. The background and net BLM-induced levels of MNs were significantly higher in all patient groups compared with the control (P < 0.01, P < 0.001, respectively). The frequency of MNs was significantly higher in those patients with prior incidence of nephropathy than those without. A positive association was observed between basal and net MN frequency among study groups and also between net genetic damages and serum creatinine value and duration of diabetes. The rate of basal and net apoptosis was significantly higher in patients with hyperglycemia. Our results indicate that increased genomic instability expressed as MNs is associated with nephropathy in all pathological stages. Therefore, implementation of MN assay in clinical level may potentially enhance the quality of management of patients with diabetes and its complications such as nephropathy. © 2016 The Author 2016. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: [email protected]