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1.
Article in English | WPRIM | ID: wpr-880631

ABSTRACT

OBJECTIVES@#Radiotherapy is one of the main therapies for colorectal cancer, but radioresistance often leads to radiotherapy failure. To improve the radioresistance, we explore the effect of oligomycin A, the H@*METHODS@#The effects of different concentrations of oligomycin A on the survival rate and glycolysis of HT29 colorectal cancer cells at different time points were investigated via MTT and glycolysis assay. siRNA-PFK1 was synthesized in vitro and transfected into HT29 cells. The effects of oligomycin A on radiosensitivity of HT29 colorectal cancer cells were measured via MTT and colony formation assay. Western blotting was used to detect the effect of oligomycin A on the expression of glycolytic enzyme PFK1. We compared difference between the effects of siRNA-PFK1 group and oligomycin A combined with siRNA-PFK1 group on cell survival and glycolysis. After 4 Gy X-ray irradiation, the effects of cell survival and glycolysis between the siRNA-PFK1 group and the oligomycin A combined with siRNA-PFK1 group were compared.@*RESULTS@#Compared with the 0 μmol/L oligomycin A group, the cell survival rate of HT29 cells treated with 4 μmol/L oligomycin A was significantly increased (@*CONCLUSIONS@#Oligomycin A can promote the radioresistance of HT29 colorectal cancer cells, which may be related to up-regulation of the PFK1 expression and increase of cell glycolysis.


Subject(s)
Cell Line, Tumor , Colorectal Neoplasms/genetics , HT29 Cells , Humans , Oligomycins/pharmacology , Radiation Tolerance
2.
Journal of Experimental Hematology ; (6): 1032-1037, 2020.
Article in Chinese | WPRIM | ID: wpr-827166

ABSTRACT

OBJECTIVE@#To explore the effect of mmu-circRNA_016901 on the regulation of radiation injury of bone marrow stem cells and its mechanism.@*METHODS@#Bone marrow stem cells were exposed to different dose of X-ray, then the expression level of mmu-circRNA_016901 in bone marrow cells treated with different doses of X-ray was detected. The luciferase reporter gene assay was used to confirm that miRNA1249-5p is the target of mmu-circRNA_016901, and RNA Binding Protein Immunoprecipitation was used to confirm that TGF-β3 is the targeted on miRNA1249-5p,the expression of TGF-β3 and cell proliferation were detected after the expression of mmu-circRNA_01690 was regulated.@*RESULTS@#When the irradiation dose<6 Gy, there were significant difference in the expression of mmn-circRNA-016901 after the bone marrow mesenchymal stem cells were treated by different doses of irradiation, which showed a statistically significant (P<0.05). The luciferase reporter gene detection and co-immunoprecipitation experiments confirmed that Mmu-circRNA_016901 could binds to miRNA1249-5p specifically, and overexpression of mmu-circRNA_016901 could regulate miRNA1249-5p negatively, which resulted in a significant increase in TGF-β3 expression and promoting of cell proliferation.@*CONCLUSION@#mmu-circRNA_016901 affects the expression of TGF-β3 through miRNA1249-5p, and thus participates in the regulation of the radiation damage mechanism of bone marrow mesenchymal stem cells.


Subject(s)
Bone Marrow Cells , Mesenchymal Stem Cells , RNA, Circular , Genetics , Radiation Tolerance
3.
Arq. bras. oftalmol ; 82(1): 38-44, Jan.-Feb. 2019. tab, graf
Article in English | LILACS | ID: biblio-973869

ABSTRACT

ABSTRACT Purpose: To evaluate the effects of ranibizumab and amfenac in human uveal melanoma cell lines and to explore the ability of these compounds to sensitize uveal melanoma cells to radiation therapy. Methods: The 92.1 human uveal melanoma cell line was cultured and subjected to the proposed treatment (ranibizumab, amfenac, and a combination of both). Proliferation, migration, and invasion assays of the 92.1 uveal melanoma cell line were assessed after pretreatment with ranibizumab (125 mg/mL), amfenac (150 nM), or a combination of both. In addition, proliferation rates were assessed after treatment with ranibizumab and amfenac, and the cells were subsequently exposed to various radiation doses (0, 4, and 8 Gy). Results: Proliferation assay: cells treated with a combination of ranibizumab and amfenac had lower proliferation rates than controls (p=0.016) and than those treated with only ranibizumab (p=0.033). Migration assay: a significantly lower migration rate was observed in cells treated with amfenac than the control (p=0.014) and than those treated with ranibizumab (p=0.044). Invasion assay: there were no significant differences among the studied groups. Irradiation exposure: in the 4 Gy dose group, there were no significant differences among any groups. In the 8 Gy dose group, treatment with ranibizumab, amfenac, and their combination prior to application of the 8 Gy radiation led to a marked reduction in proliferation rates (p=0.009, p=0.01, and p=0.034, respectively) compared with controls. Conclusion: Combination of ranibizumab and amfenac reduced the proliferation rate of uveal melanoma cells; however, only amfenac monotherapy significantly decreased cell migration. The radiosensitivity of the 92.1 uveal melanoma cell line increased following the administration of ranibizumab, amfenac, and their combination. Further investigation is warranted to determine if this is a viable pretreatment strategy to render large tumors amenable to radiotherapy.


RESUMO Objetivo: Avaliar os efeitos do ranibizumabe em associação com o amfenac nas células de melanoma uveal humano e explorar a capacidade desses compostos em sensibilizar as células de melanoma uveal à radioterapia. Métodos: Células de melanoma uveal humano do tipo 92.1 foram cultivadas e submetidas ao tratamento proposto (ranibizumabe, amfenac e a combinação de ambos). Ensaios de proliferação, migração e invasão com as células de melanoma uveal do tipo 92.1 foram avaliados após tratamento com ranibizumabe (125 mg/ml), amfenac (150 nM) e a combinação de ambos. Além disso, as taxas de proliferação foram avaliadas após tratamento com ranibizumabe e amfenac com subsequente exposição das células a diferentes doses de radiação (0 Gy, 4 Gy e 8 Gy). Resultados: Ensaio de proliferação: células tratadas com ranibizumabe e amfenac combinados apresentaram taxas de proliferação inferiores em comparação ao grupo controle (p=0,016), do que as tratadas apenas com ranibizumabe (p=0,033). Ensaio de migração: foi observada uma taxa de migração significativamente mais baixa nas células tratadas com amfenac do que no grupo controle (p=0,014) e do que nas tratadas com ranibizumabe (p=0,044). Ensaio de invasão: não houve diferenças significativas entre os grupos estudados. Exposição à irradiação: no grupo da dose de 4 Gy, não houve diferença significante entre os grupos. No grupo da dose de 8 Gy, o tratamento com ranibizumabe, afenac e sua combinação antes da aplicação da radiação de 8 Gy levou a uma redução acentuada nas taxas de proliferação (p=0,009, p=0,01 e p=0,034, respectivamente) em comparação aos grupos controle. Conclusão: A combinação de ranibizumabe e amfenac reduziu a taxa de proliferação das células de melanoma uveal; no entanto, apenas o amfenac diminuiu significativamente a migração celular. A radiossensibilidade das células de melanoma uveal do tipo 92.1 aumentou após a administração de ranibizumabe, amfenac e sua combinação. Mais investigações são necessárias para determinar se esta é uma estratégia de pré-tratamento viável para tornar grandes tumores passíveis de radioterapia.


Subject(s)
Humans , Phenylacetates/pharmacology , Angiogenesis Inhibitors/pharmacology , Cyclooxygenase 2 Inhibitors/pharmacology , Ranibizumab/pharmacology , Melanoma/drug therapy , Melanoma/radiotherapy , Radiation Tolerance , Uveal Neoplasms/drug therapy , Uveal Neoplasms/radiotherapy , Antineoplastic Combined Chemotherapy Protocols , Cell Movement/drug effects , Cell Movement/radiation effects , Reproducibility of Results , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Proliferation/radiation effects , Dose-Response Relationship, Radiation
4.
Article in Chinese | WPRIM | ID: wpr-777465

ABSTRACT

Modern pharmacological studies have shown that Shengmai San has the effects of enhancing immunity and improving blood circulation, and Curcumae Longae Rhizoma(Jianghuang) has anti-inflammatory, anti-cancer, anti-oxidation and other functions. Shengmai San combined with Jianghuang is a new research direction in the study of anti-tumor of traditional Chinese medicines. The main treatment for nasopharyngeal carcinoma is radiation therapy, but radiation therapy can cause a variety of side effects, and it also changes the composition of the intestinal flora. In this study, the 16 s rDNA sequencing platform was used to perform macro-sequence sequencing of the intestinal flora samples of nude mice bearing the veins of Shengmai Jianghuang San, and then the results of intestinal flora data were analyzed to investigate the effect of Shengmai Jianghuang San on tumors. The results showed that Shengmai Jianghuang San combined with irradiation could enhance the therapeutic effect of tumor treatment. Radiation therapy would reduce the total number and diversity of intestinal flora in nude mice, and also change the structure of the flora. Shengmai Jianghuang San could protect the diversity of colonies, and also partially restore the colony imbalance caused by irradiation. This study provides a research idea for Shengmai Jianghuang San as a sensitizing adjuvant for radiotherapy of nasopharyngeal carcinoma.


Subject(s)
Animals , Drugs, Chinese Herbal , Pharmacology , Gastrointestinal Microbiome , Mice , Mice, Nude , Nasopharyngeal Carcinoma , Radiotherapy , Radiation Tolerance , Radiation-Sensitizing Agents , Pharmacology
5.
Article in English | WPRIM | ID: wpr-763126

ABSTRACT

PURPOSE: Glioblastoma, the most common brain tumor in adults, has poor prognosis. The purpose of this study was to determine the effect of disulfiram (DSF), an aldehyde dehydrogenase inhibitor, on in vitro radiosensitivity of glioblastoma cells with different methylation status of O⁶-methylguanine-DNA methyltransferase (MGMT) promoter and the underlying mechanism of such effect. MATERIALS AND METHODS: Five human glioblastoma cells (U138MG, T98G, U251MG, U87MG, and U373MG) and one normal human astrocyte (NHA) cell were cultured and treated with DSF or 6MV X-rays (0, 2, 4, 6, and 8 Gy). For combined treatment, cells were treated with DSF before irradiation. Surviving fractions fit from cell survival based on colony forming ability. Apoptosis, DNA damage repair, and cell cycle distributionwere assayed bywestern blot for cleaved caspase-3, γH2AX staining, and flow cytometry, respectively. RESULTS: DSF induced radiosensitization in most of the glioblastoma cells, especially, in the cells with radioresistance as wildtype unmethylated promoter (MGMT-wt), but did not in normal NHA cell. DSF augmented or induced cleavage of caspase-3 in all cells after irradiation. DSF inhibited repair of radiation-induced DNA damage in MGMT-wt cells, but not in cells with methylated MGMT promoter. DSF abrogated radiation-induced G2/M arrest in T98G and U251MG cells. CONCLUSION: Radiosensitivity of glioblastoma cells were preferentially enhanced by pre-irradiation DSF treatment compared to normal cell, especially radioresistant cells such as MGMT-wt cells. Induction of apoptosis or inhibition of DNA damage repair may underlie DSF-induced radiosensitization. Clinical benefit of combining DSF with radiotherapy should be investigated in the future.


Subject(s)
Adult , Aldehyde Dehydrogenase , Apoptosis , Astrocytes , Brain Neoplasms , Caspase 3 , Cell Cycle , Cell Survival , Disulfiram , DNA Damage , Flow Cytometry , Glioblastoma , Humans , In Vitro Techniques , Methylation , Prognosis , Radiation Tolerance , Radiotherapy
6.
Article in English | WPRIM | ID: wpr-719419

ABSTRACT

PURPOSE: Intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI)was evaluated regarding its ability to preliminarily predict the short-term treatment response of nasopharyngeal carcinoma (NPC) following intensity-modulated radiation therapy. MATERIALS AND METHODS: IVIM-DWI with 14 b-factors (0-1,000 sec/mm2) was performed with a 3T MR system on 47 consecutive NPCs before, during (end of the 5th, 10th, 15th, 20th, and 25th fractions), and after fractional radiotherapy. IVIM parametrics (D, f, and D*) were calculated and compared to the baseline and xth fraction. Patients were categorized into responders and non-responders after radiotherapy. IVIM parametrics were also compared between subgroups. RESULTS: After fractional radiations, the D (except D5 and D at the end of the 5th fraction) after radiations were larger than the baseline D0 (p < 0.05), and the post-radiation D* (except D*5 and D*10) were smaller than D*0 (p < 0.05). f0 was smaller than f5 and f10 (p < 0.001) but larger than fend (p < 0.05). Furthermore, greater D5, D10, D15, and f10 coupled with smaller f0, D*20, and D*25 were observed in responders than non-responders (all p < 0.01). Responders also presented larger ΔD10, Δf10, ΔD*20, and δD*20 than non-responders (p < 0.05). Receiver operating characteristic curve analysis indicated that the D5, D*20, and f10 could better differentiate responders from non-responders. CONCLUSION: IVIM-DWI could efficiently assess tumor treatment response to fractional radiotherapy and predict the radio-sensitivity for NPCs.


Subject(s)
Diffusion , Humans , Radiation Tolerance , Radiotherapy , Radiotherapy, Intensity-Modulated , ROC Curve
7.
Braz. j. med. biol. res ; 51(6): e7080, 2018. graf
Article in English | LILACS | ID: biblio-889093

ABSTRACT

Prostate cancer (PCa) is the second leading cause of cancer death in men. Irradiation is one of the available options for treatment of PCa, however, approximately 10-45% of PCa are resistant to irradiation. We aimed to explore the role of long non-coding RNA highly upregulated in liver cancer (HULC) in the sensitivity of PCa cells to irradiation. Survival rate, cell apoptosis, cycle, expressions of related proteins, and caspase-3 activity were assessed to explore the effects of HULC on sensitivity of PCa cells to irradiation. Expression of HULC in DU-145, PC3, LNCaP, and RWPE-1 cells was determined and the influence of HULC on DU-145 cells was explored. Then, PC3 cells aberrantly expressing HULC were implanted into NOD-SCID mice for tumor xenograft study. Changes of autophagy after aberrant expression of HULC in vivo and in vitro were tested. Furthermore, the interacted protein of HULC and involved signaling pathway were investigated. In PC3 and LNCaP cells under irradiation, survival rate and cell cycle were decreased and apoptosis was increased by HULC knockdown. HULC knockdown arrested PC3 cells at G0/G1 phase. DU-145 was sensitive to irradiation, and resistance to irradiation of DU-145 cells was enhanced by HULC overexpression. Moreover, HULC knockdown enhanced the sensitivity of PC3 xenografts to irradiation. HULC knockdown promoted autophagy through interaction with Beclin-1 and inhibition of mTOR, resulting in increased apoptosis. HULC knockdown improved sensitivity of PCa cells to irradiation both in vivo and in vitro. HULC suppressed Beclin-1 phosphorylation, thereby reduced autophagy, involving the mTOR pathway.


Subject(s)
Humans , Male , Autophagy/radiation effects , Prostatic Neoplasms/pathology , Radiation Tolerance/physiology , RNA, Long Noncoding/radiation effects , Apoptosis/radiation effects , Blotting, Western , Cell Line, Tumor/radiation effects , Real-Time Polymerase Chain Reaction , RNA Interference/radiation effects , Transfection
8.
Biol. Res ; 51: 56, 2018. graf
Article in English | LILACS | ID: biblio-1011400

ABSTRACT

BACKGROUND: Glioma is the most prevalent malignant tumor in human central nervous systems. Recently, the development of resistance to radiotherapy in glioma patients markedly vitiates the therapy outcome. MiR-153-3p has been reported to be closely correlated with tumor progression, but its effect and molecular mechanism underlying radioresistance remains unclear in glioma. METHODS: The expression of miR-153-3p was determined in radioresistant glioma clinical specimens as well as glioma cell lines exposed to irradiation (IR) using quantitative real-time PCR. Cell viability, proliferation and apoptosis were then evaluated by MTT assay, colony formation assay, Flow cytometry analysis and caspase-3 activity assay in glioma cells (U87 and U251). Tumor forming was evaluated by nude mice model in vivo. TUNEL staining was used to detect cell apoptosis in nude mice model. The target genes of miR-153-3p were predicted and validated using integrated bioinformatics analysis and a luciferase reporter assay. RESULTS: Here, we found that miR-153-3p was down-regulated in radioresistant glioma clinical specimens as well as glioma cell lines (U87 and U251) exposed to IR. Enhanced expression of miR-153-3p promoted the radiosensitivity, promoted apoptosis and elevated caspase-3 activity in glioma cells in vitro, as well as the radiosensitivity in U251 cell mouse xenografs in vivo. Mechanically, B cell lymphoma-2 gene (BCL2) was identified as the direct and functional target of miR-153-3p. Moreover, restoration of BCL2 expression reversed miR-153-3p-induced increase of radiosensitivity, apoptosis and caspase-3 activity in U251 cells in vitro. In addition, clinical data indicated that the expression of miR-153-3p was significantly negatively associated with BCL2 in radioresistance of glioma samples. CONCLUSIONS: Our findings suggest that miR-153-3p is a potential target to enhance the effect of radiosensitivity on glioma cells, thus representing a new potential therapeutic target for glioma.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Radiation Tolerance/genetics , Genes, bcl-2/physiology , MicroRNAs/radiation effects , MicroRNAs/physiology , Glioma/genetics , Time Factors , Down-Regulation , Gene Expression Regulation, Neoplastic , Cell Survival/radiation effects , Blotting, Western , Analysis of Variance , Gene Targeting/methods , Genes, bcl-2/radiation effects , In Situ Nick-End Labeling , MicroRNAs/analysis , Cell Line, Tumor , Cell Proliferation/radiation effects , Caspase 3/analysis , Real-Time Polymerase Chain Reaction , Flow Cytometry , Glioma/radiotherapy
9.
Cancer Research and Treatment ; : 1203-1213, 2018.
Article in English | WPRIM | ID: wpr-717747

ABSTRACT

PURPOSE: This study aimed to explore the functions and mechanisms of C-C motif chemokine receptor 6 (CCR6), a gene associated with progression and metastasis of colorectal cancer (CRC), in radiosensitivity of rectal cancer (RC). MATERIALS AND METHODS: RNA sequencing and immunohistochemical analysis on CCR6 expression were performed in pretreatment tissues of RC patients exhibiting different therapeutic effects of radiotherapy. Colonogenic survival assay was conducted in different CRC cell lines to assess their radiosensitivity. And the impact of CCR6 expression on radiosensitivity was validated through RNA interference. The DNA damage repair (DDR) abilities of cell lines with different CCR6 expression were evaluated through immunofluorescence-based γH2AX quantification. RESULTS: The CCR6 mRNA level was higher in patients without pathologic complete remission (pCR) than in those with pCR (fold changed, 2.11; p=0.004). High-level expression of CCR6 protein was more common in the bad responders than in the good responders (76.3% vs. 37.5%, p < 0.001). The CRC cell lines with higher CCR6 expression (LoVo and sw480) appeared to be more radioresistant, compared with the sw620 cell line which had lower CCR6 expression. CCR6 knockdown made the LoVo cells more sensitive to ionizing radiation (sensitization enhancement ratio, 1.738; p < 0.001), and decreased their DDR efficiency. CONCLUSION: CCR6 might affect the RC radiosensitivity through DDR process. These findings supported CCR6 as a predicting biomarker of radiosensitivity and a potential target of radiosensitization for RC patients.


Subject(s)
Cell Line , Colorectal Neoplasms , DNA Damage , Genes, vif , Humans , Neoplasm Metastasis , Polymerase Chain Reaction , Radiation Tolerance , Radiation, Ionizing , Radiotherapy , Rectal Neoplasms , RNA Interference , RNA, Messenger , Sequence Analysis, RNA , Therapeutic Uses
10.
Radiation Oncology Journal ; : 265-275, 2018.
Article in English | WPRIM | ID: wpr-741964

ABSTRACT

Cancer is a complex multifaceted illness that affects different patients in discrete ways. For a number of cancers the use of chemotherapy has become standard practice. Chemotherapy is a use of cytostatic drugs to cure cancer. Cytostatic agents not only affect cancer cells but also affect the growth of normal cells; leading to side effects. Because of this, radiotherapy gained importance in treating cancer. Slaughtering of cancerous cells by radiotherapy depends on the radiosensitivity of the tumor cells. Efforts to improve the therapeutic ratio have resulted in the development of compounds that increase the radiosensitivity of tumor cells or protect the normal cells from the effects of radiation. Amifostine is the only chemical radioprotector approved by the US Food and Drug Administration (FDA), but due to its side effect and toxicity, use of this compound was also failed. Hence the use of herbal radioprotectors bearing pharmacological properties is concentrated due to their low toxicity and efficacy. Notably, in silico methods can expedite drug discovery process, to lessen the compounds with unfavorable pharmacological properties at an early stage of drug development. Hence a detailed perspective of these properties, in accordance with their prediction and measurement, are pivotal for a successful identification of radioprotectors by drug discovery process.


Subject(s)
Amifostine , Computer Simulation , Cytostatic Agents , Drug Discovery , Drug Therapy , Humans , Quantitative Structure-Activity Relationship , Radiation Tolerance , Radiotherapy , United States Food and Drug Administration
11.
An. acad. bras. ciênc ; 89(1,supl): 649-659, May. 2017. graf
Article in English | LILACS | ID: biblio-886652

ABSTRACT

ABSTRACT Several molecules and events involved in cell response to radiation-induced damage have been investigated towards a personalized radiotherapy. Considering the importance of active caspase-3 in the proteolytic cascade that ensures radiation-induced apoptosis execution, this research was designed to evaluate the expression levels of this protein as a bioindicator of individual radiosensitivity. Peripheral blood samples of 10 healthy individuals were gamma-irradiated (cobalt-60 source) with 1, 2 and 4 Gy (control: non-irradiated samples), and active caspase-3 expression levels were measured in lymphocytes, by flow cytometry, ex vivo and after different times of in vitro incubation (24, 48 and 72 hours). Short-term incubation of 24 h was the most adequate condition to evidence correlations between dose radiation and active caspase-3 expression. For each radiation dose, it was observed a significant inter-individual variation in active caspase-3 expression intensity, suggesting that this parameter may be suitable for evidence individual radiosensitivity. The methodology presented and discussed in this work may help to predict healthy tissues response to radiation exposure toward the better patient outcome.


Subject(s)
Humans , Male , Female , Adult , Radiation Tolerance/radiation effects , Lymphocytes/radiation effects , Cobalt Radioisotopes , Apoptosis/radiation effects , Caspase 3/metabolism , Lymphocytes/enzymology , Environmental Biomarkers , Dose-Response Relationship, Radiation , Flow Cytometry
12.
Arch. endocrinol. metab. (Online) ; 61(1): 81-89, Jan.-Feb. 2017. tab
Article in English | LILACS | ID: biblio-838415

ABSTRACT

ABSTRACT Radioiodine (RAI)-refractory thyroid cancer is an uncommon entity, occurring with an estimated incidence of 4-5 cases/year/million people. RAI refractoriness is more frequent in older patients, in those with large metastases, in poorly differentiated thyroid cancer, and in those tumors with high 18-fluordeoxyglucose uptake on PET/CT. These patients have a 10-year survival rate of less than 10%. In recent years, new therapeutic agents with molecular targets have become available, with multikinase inhibitors (MKIs) being the most investigated drugs. Two of these compounds, sorafenib and lenvatinib, have shown significant objective response rates and have significantly improved the progression-free survival in the two largest published prospective trials on MKI use. However, no overall survival benefit has been achieved yet. This is probably related to the crossover that occurs in most patients who progress on placebo treatment to the open treatment of these studies. In consequence, the challenge is to correctly identify which patients will benefit from these treatments. It is also crucial to understand the appropriate timing to initiate MKI treatment and when to stop it. The purpose of this article is to define RAI refractoriness, to summarize which therapies are available for this condition, and to review how to select patients who are suitable for them.


Subject(s)
Humans , Thyroid Neoplasms/drug therapy , Protein Kinase Inhibitors/therapeutic use , Iodine Radioisotopes/therapeutic use , Antineoplastic Agents/therapeutic use , Radiation Tolerance , Thyroid Neoplasms/mortality , Thyroid Neoplasms/radiotherapy , Treatment Failure , Retreatment , Disease Management
13.
Biol. Res ; 50: 27, 2017. graf
Article in English | LILACS | ID: biblio-950878

ABSTRACT

BACKGROUND: miR-22 has been shown to be frequently downregulated and act as a tumor suppressor in multiple cancers including breast cancers. However, the role of miR-22 in regulating the radioresistance of breast cancer cells, as well as its underlying mechanism is still not well understood. METHODS: The expressions of miR-22 and sirt1 at mRNA and protein levels were examined by qRT-PCR and Western Blot. The effects of miR-22 overexpression and sirt1 knockdown on cell viability, apoptosis, radiosensitivity, γ-H2AX foci formation were evaluated by CCK-8 assay, flow cytometry, colony formation assay, and γ-H2AX foci formation assay, respectively. Luciferase reporter assay and qRT-PCR analysis were performed to confirm the interaction between miR-22 and sirt1. RESULTS: miR-22 was downregulated and sirt1 was upregulated at both mRNA and protein levels in breast cancer cells. miR-22 overexpression or sirt1 knockdown significantly suppressed viability, induced apoptosis, reduced survival fraction, and increased the number of γ-H2AX foci in breast cancer cells. Sirt1 was identified as a target of miR-22 and miR-22 negatively regulated sirt1 expression. Ectopic expression of sirt1 dramatically reversed the inhibitory effect of miR-22 on cell viability and promotive effect on apoptotic rates and radiosensitivity in breast cancer cells. CONCLUSIONS: miR-22 suppresses tumorigenesis and improves radiosensitivity of breast cancer cells by targeting sirt1, providing a promising therapeutic target for breast cancer.


Subject(s)
Humans , Female , Radiation Tolerance , Breast Neoplasms/radiotherapy , MicroRNAs/metabolism , Sirtuin 1/metabolism , Radiotherapy Dosage , Breast Neoplasms/metabolism , Histones/metabolism , Down-Regulation , Gene Expression Regulation, Neoplastic , Cell Survival , Apoptosis/genetics , Cell Line, Tumor , Gene Knockdown Techniques , Sirtuin 1/genetics
14.
Article in English | WPRIM | ID: wpr-101936

ABSTRACT

PURPOSE: This study was conducted to investigate the role of four polymorphic variants of DNA methyltransferase genes as risk factors for radiation-induced fibrosis in breast cancer patients. We also assessed their ability to improve prediction accuracy when combined with mitochondrial haplogroup H, which we previously found to be independently associated with a lower hazard of radiation-induced fibrosis. MATERIALS AND METHODS: DNMT1 rs2228611,DNMT3A rs1550117,DNMT3A rs7581217, and DNMT3B rs2424908 were genotyped by real-time polymerase chain reaction in 286 Italian breast cancer patients who received radiotherapy after breast conserving surgery. Subcutaneous fibrosis was scored according to the Late Effects of Normal Tissue–Subjective Objective Management Analytical (LENT-SOMA) scale. The discriminative accuracy of genetic models was assessed by the area under the receiver operating characteristic curves (AUC). RESULTS: Kaplan-Meier curves showed significant differences among DNMT1 rs2228611 genotypes in the cumulative incidence of grade ≥ 2 subcutaneous fibrosis (log-rank test p-value= 0.018). Multivariate Cox regression analysis revealed DNMT1 rs2228611 as an independent protective factor for moderate to severe radiation-induced fibrosis (GG vs. AA; hazard ratio, 0.26; 95% confidence interval [CI], 0.10 to 0.71; p=0.009). Adding DNMT1 rs2228611 to haplogroup H increased the discrimination accuracy (AUC) of the model from 0.595 (95% CI, 0.536 to 0.653) to 0.655 (95% CI, 0.597 to 0.710). CONCLUSION: DNMT1 rs2228611 may represent a determinant of radiation-induced fibrosis in breast cancer patients with promise for clinical usefulness in genetic-based predictive models.


Subject(s)
Breast Neoplasms , Breast , Discrimination, Psychological , DNA , Fibrosis , Genotype , Humans , Incidence , Mastectomy, Segmental , Models, Genetic , Polymorphism, Single Nucleotide , Protective Factors , Radiation Tolerance , Radiotherapy , Real-Time Polymerase Chain Reaction , Risk Factors , ROC Curve , Skin
15.
Article in English | WPRIM | ID: wpr-26792

ABSTRACT

PURPOSE: We investigated the effect of chemoradiotherapy with PP2 and temozolomide (TMZ) on malignant glioma cells using clonogenic assays and in vivo brain tumor model. MATERIALS AND METHODS: The effect of PP2 on radiosensitivity of U251 and T98G cells was investigated using clonogenic assays. The expression of E-cadherin, matrix metalloproteinases 2 (MMP2), Ephrin type-A receptor 2 (EphA2), and vascular endothelial growth factor (VEGF) was measured by Western blotting and an accumulation of γH2AX foci 6 hours after radiotherapy was measured after PP2 treatment. The effect of PP2 on migration, invasion, and vasculogenic mimicry formation (VMF) of U251 cells was evaluated. In an orthotopical brain tumor model with U251 cells, PP2 was injected intraperitoneally with or without oral TMZ before, during and after whole brain radiotherapy. Bioluminescence images were taken to visualize in vivo tumors and immunohistochemical staining of VEGF, CD31, EphA2, and hypoxia-inducible factor 1a was performed. RESULTS: PP2 increased radiosensitivity of U251 and T98G cells without decreasing survival of normal human astrocytes. Chemoradiotherapy with PP2 and TMZ resulted in increased accumulation of γH2AX foci. PP2 induced overexpression of E-cadherin and suppression of MMP2, VEGF, and EphA2. PP2 also compromised invasion, migration, and VMF of U251 cells. In brain tumors, chemoradiotherapy with PP2 and TMZ decreased tumor volume best, but not statistically significantly compared with chemoradiotherapy with TMZ. The expression of VEGF and CD31 was suppressed in PP2-treated tumors. CONCLUSION: PP2 enhances radiosensitivity of malignant glioma cells and suppresses invasion and migration of U251 cells. Chemoradiotherapy with PP2 and TMZ resulted in non-significant tumor volume decrease.


Subject(s)
Astrocytes , Blotting, Western , Brain , Brain Neoplasms , Cadherins , Chemoradiotherapy , Glioblastoma , Glioma , Humans , Matrix Metalloproteinases , Protein-Tyrosine Kinases , Radiation Tolerance , Radiotherapy , Tumor Burden , Tyrosine , Vascular Endothelial Growth Factor A
16.
Article in English | WPRIM | ID: wpr-30879

ABSTRACT

Ataxia-telangiectasia (AT) is characterized by cerebellar ataxia, progressive immunodeficiency, radiation sensitivity, telangiectasia, and predisposition to malignancy. AT patients have a 100-fold increased risk for the development of lymphoid malignancies. It is important to consider AT in a child with pre-existing ataxia, or lymphoid malignancy that was diagnosed at a younger age than expected. This consideration avoids the confusion between ataxia development and toxicity from chemotherapy. Hodgkin's lymphoma (HL) is usually treated with chemotherapy and/or radiotherapy. Unfortunately, when treated with conventional doses of radiotherapy, AT patients invariably experience devastating necrosis of their normal tissues. Therefore, a new treatment protocol for patients with HL in AT must be established. In this paper, we report the case of an 8-year-old female patient with HL in AT who was treated with chemotherapy. This patient was also treated with brentuximab (which targets CD30) for salvage therapy after the disease progressed.


Subject(s)
Ataxia , Ataxia Telangiectasia , Cerebellar Ataxia , Child , Clinical Protocols , Drug Therapy , Female , Hodgkin Disease , Humans , Necrosis , Radiation Tolerance , Radiotherapy , Salvage Therapy , Telangiectasis
17.
Article in English | WPRIM | ID: wpr-44795

ABSTRACT

PURPOSE: In a previous study, the transmembrane protein FXYD-3 was suggested as a biomarker for a lower survival rate and reduced radiosensitivity in rectal cancer patients receiving preoperative radiotherapy. The purpose of preoperative irradiation in rectal cancer is to reduce local recurrence. The aim of this study was to investigate the potential role of FXYD-3 as a biomarker for increased risk for local recurrence of rectal cancer. MATERIALS AND METHODS: FXYD-3 expression was immunohistochemically examined in surgical specimens from a cohort of patients with rectal cancer who developed local recurrence (n = 48). The cohort was compared to a matched control group without recurrence (n = 81). RESULTS: Weak FXYD-3 expression was found in 106/129 (82%) of the rectal tumors and strong expression in 23/129 (18%). There was no difference in the expression of FXYD-3 between the patients with local recurrence and the control group. Furthermore there was no difference in FXYD-3 expression and time to diagnosis of local recurrence between patients who received preoperative radiotherapy and those without. CONCLUSION: Previous findings indicated that FXYD-3 expression may be used as a marker of decreased sensitivity to radiotherapy or even overall survival. We were unable to confirm this in a cohort of rectal cancer patients who developed local recurrence.


Subject(s)
Cohort Studies , Diagnosis , Humans , Radiation Tolerance , Radiotherapy , Rectal Neoplasms , Recurrence , Survival Rate
18.
Cancer Research and Treatment ; : 1130-1140, 2016.
Article in English | WPRIM | ID: wpr-68881

ABSTRACT

PURPOSE: Histone deacetylase (HDAC) inhibitors radiosensitize tumor cells. To elucidate mechanisms underlying radiosensitization by HDAC inhibition, understanding of differential contributions of HDAC isotypes is needed. The aim of this study was to investigate involvement of known HDAC isotypes in modulation of cellular radiosensitivity. MATERIALS AND METHODS: Because pharmacologic HDAC inhibitors lack isotype-specificity, RNA interference against 11 HDAC isotypes was used to inhibit HDAC in an isotype-specific manner. Radiation cell survival was evaluated using a clonogenic assay in SQ20B cells transfected with small interfering RNA specifically targeting HDAC isotypes. Immunocytochemistry was performed for detection of γH2AX foci. Protein expression was measured using Western blotting. RESULTS: Among 11 HDAC isotypes tested, specific inhibition of 7 isotypes (HDAC1, HDAC3, HDAC4, HDAC6, HDAC7, HDAC10, and HDAC11) enhanced radiation lethality in SQ20B cells. Radiosensitization by inhibition of these HDAC isotypes was accompanied by delay of DNA double strand break repair. Radiosensitivity of SQ20B cells was not altered by selective inhibition of the remaining four isotypes (HDAC2, HDAC5, HDAC8, and HDAC9). Inhibition of HDAC isotypes resulted in downregulation of various proteins involved in pro-survival and DNA damage repair pathways. CONCLUSION: Isotype-specificity exists in HDAC inhibition-induced radiosensitization. Different HDAC isotypes are differentially involved in modulation of cellular radiosensitivity.


Subject(s)
Blotting, Western , Cell Survival , DNA , DNA Damage , Down-Regulation , Histone Deacetylase Inhibitors , Histone Deacetylases , Histones , Immunohistochemistry , Radiation Tolerance , Radiation, Ionizing , RNA Interference , RNA, Small Interfering
19.
Article in English | WPRIM | ID: wpr-61890

ABSTRACT

PURPOSE: Reactive oxygen species (ROS) are generated as an indirect product of radiation therapy (RT). Genetic variation in genes related to ROS metabolism may influence the level of RT-induced adverse effects. We evaluated the potential association of single nucleotide polymorphism (SNP)-related response to radiotherapy injury in breast cancer patients undergoing RT. MATERIALS AND METHODS: Eighty patients receiving conventional RT were included. Acute effects were evaluated according to the Radiation Therapy Oncology Group (RTOG) scores. DNA was extracted from blood and buccal swab samples. SNPs were genotyped for GSTP1, GSTA1, SOD2, and NOS3 genes by polymerase chain reaction-based restriction fragment length polymorphism. Univariate analysis (odds ratios [ORs] and 95% confidence interval [CI]) and principal component analysis were used for correlation of SNPs and factors related to risk of developing ≥ grade 2 acute effects. RESULTS: Sixty-five patients (81.2%) showed side effects, 32 (40%) presented moderate to severe acute skin toxicity, and 33 (41.2%) manifested minimal acute skin reactions by the end of treatment. In both univariate and multivariate analyses, nominally significant associations were found among body mass index (OR, 3.14; 95% CI, 8.5338 to 1.1274; p=0.022), breast size (OR, 5.11; 95% CI, 17.04 to 1.54; p=0.004), and grade ≥ 2 acute radiation skin toxicity. A significant association was also observed between NOS3 G894T polymorphism (OR, 9.8; 95% CI, 211.6 to 0.45; p=0.041) and grade ≥ 2 acute radiation skin toxicity in patients with neo-adjuvant chemotherapy treatment. CONCLUSION: The analysis of the factors involved in individual radiosensitivity contributed to the understanding of the mechanisms underlying this trait.


Subject(s)
Body Mass Index , Breast Neoplasms , Breast , DNA , Drug Therapy , Genetic Variation , Humans , Metabolism , Multivariate Analysis , Oxidative Stress , Polymorphism, Restriction Fragment Length , Polymorphism, Single Nucleotide , Principal Component Analysis , Radiation Tolerance , Radiotherapy , Reactive Oxygen Species , Skin
20.
Article in English | WPRIM | ID: wpr-66008

ABSTRACT

Inevitable human exposure to ionizing radiation from man-made sources has been increased with the proceeding of human civilization and consequently public concerns focus on the possible risk to human health. Moreover, Fukushima nuclear power plant accidents after the 2011 East-Japan earthquake and tsunami has brought the great fear and anxiety for the exposure of radiation at low levels, even much lower levels similar to natural background. Health effects of low dose radiation less than 100 mSv have been debated whether they are beneficial or detrimental because sample sizes were not large enough to allow epidemiological detection of excess effects and there was lack of consistency among the available experimental data. We have reviewed an extensive literature on the low dose radiation effects in both radiation biology and epidemiology, and highlighted some of the controversies therein. This article could provide a reasonable view of utilizing radiation for human life and responding to the public questions about radiation risk. In addition, it suggests the necessity of integrated studies of radiobiology and epidemiology at the national level in order to collect more systematic and profound information about health effects of low dose radiation.


Subject(s)
DNA Damage/drug effects , Environmental Exposure , Humans , Leukemia/epidemiology , Neoplasms, Radiation-Induced/epidemiology , Radiation Dosage , Radiation Tolerance , Radiation, Ionizing , Radioactive Hazard Release , Risk
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