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Autophagy and radiation resistance

Peidang Liu, Haizhen Jin, Zhirui Guo, Jun Ma, Jing Zhao, Dongdong Li, Hao Wu, Ning Gu
Radiotherapy performs an important function in the treatment of cancer, but resistance of tumor cells to radiation still remains a serious concern. More research on more effective radiosensitizers is urgently needed to overcome such resistance and thereby improve the treatment outcome. The goal of this study was to evaluate and compare the radiosensitizing efficacies of gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) on glioma at clinically relevant megavoltage energies. Both AuNPs and AgNPs potentiated the in vitro and in vivo antiglioma effects of radiation...
2016: International Journal of Nanomedicine
Fernanda Antunes, Marco Corazzari, Gustavo Pereira, Gian Maria Fimia, Mauro Piacentini, Soraya Smaili
Melanoma is one of leading cause of tumor death worldwide. Anti-cancer strategy includes combination of different chemo-therapeutic agents as well as radiation; however these treatments have limited efficacy and induce significant toxic effects on healthy cells. One of most promising novel therapeutic approach to cancer therapy is the combination of anti-cancer drugs with calorie restriction. Here we investigated the effect Cisplatin (CDDP), one of the most potent chemotherapeutic agent used to treat tumors, in association with fasting in wild type and mutated BRAF(V600E) melanoma cell lines...
September 29, 2016: Biochemical and Biophysical Research Communications
Prasad Sulkshane, Tanuja Teni
We have previously reported overexpression of antiapoptotic MCL-1 protein in human oral cancers and its association with therapy resistance and poor prognosis, implying it to be a potential therapeutic target. Hence, we investigated the efficacy and mechanism of action of Obatoclax, a BH3 mimetic pan BCL-2 inhibitor in human oral cancer cell lines. All cell lines exhibited high sensitivity to Obatoclax with complete clonogenic inhibition at 200-400 nM concentration which correlated with their MCL-1 expression...
August 5, 2016: Oncotarget
Ebrahim Eftekhar, Hajar Jaberie, Fakhraddin Naghibalhossaini
Understanding the mechanism of tumor resistance is critical for cancer therapy. In this study, we investigated the effect of carcinoembryonic antigen (CEA) overexpression on UV-and 5-fluorouracil (5-FU)-induced apoptosis and autophagy in colorectal cancer cells. We used histone deacetylase (HDAC) inhibitor, NaB and DNA demethylating agent, 5-azacytidine (5-AZA) to induce CEA expression in HT29/219 and SW742 colorectal cancer cell lines. MTT assay was used to measure IC50 value of the cells exposed to graded concentrations of 5- FU with either 0...
2016: International Journal of Molecular and Cellular Medicine
V V Senichkin, G S Kopeina, A V Zamaraev, I N Lavrik, B D Zhivotovsky
The main objective of anticancer treatment is the elimination of degenerated cells by the induction of programmed cell death. Various chemotherapy drugs and radiation are able to activate cell death mechanisms in tumors. However, unfortunately, monotherapy will always be insufficiently effective because of the variety and virulence of tumors, as well as their ability to develop resistance to drugs. Moreover, monotherapy might constrain many negative side effects. Therefore, the combination of different approaches and/or drugs will increase the efficiency of treatment...
May 2016: Molekuliarnaia Biologiia
Ilias V Karagounis, Dimitra Kalamida, Achilleas Mitrakas, Stamatia Pouliliou, Maria V Liousia, Alexandra Giatromanolaki, Michael I Koukourakis
BACKGROUND: The cellular autophagic response to radiation is complex. Various cells and tissues respond differentially to radiation, depending on both the dose of exposure and the time post irradiation. In the current study, we determined the autophagosomal and lysosomal response to radiation in lung cancer cell lines by evaluating the expression of the associated proteins, as well as the effect of relevant gene silencing in radio and chemosensitisation. Furthermore, tumour sensitisation was evaluated in in vivo autophagic gene silencing model after irradiation...
July 26, 2016: British Journal of Cancer
Young-Mi Kim, Ji-Man Park, Douglas Grunwald, Do-Hyung Kim
Mechanistic target of rapamycin complex 1 (mTORC1) negatively regulates autophagy at early stages by phosphorylating Unc51-like kinase 1 (ULK1). Our recent study expanded the roles of mTORC1 in autophagy by identifying ultraviolet radiation resistance-associated gene product (UVRAG) as a substrate of mTORC1. This finding has provided new insight into the roles of mTORC1 in cellular membrane processes and cancer.
January 2016: Molecular & Cellular Oncology
Yongfei Yang, Shanshan He, Qiaoxiu Wang, Fan Li, Mi-Jeong Kwak, Sally Chen, Douglas O'Connell, Tian Zhang, Sara Dolatshahi Pirooz, YongHeui Jeon, Nyam-Osor Chimge, Baruch Frenkel, Younho Choi, Grace M Aldrovandi, Byung-Ha Oh, Zengqiang Yuan, Chengyu Liang
UV-induced DNA damage, a major risk factor for skin cancers, is primarily repaired by nucleotide excision repair (NER). UV radiation resistance-associated gene (UVRAG) is a tumor suppressor involved in autophagy. It was initially isolated as a cDNA partially complementing UV sensitivity in xeroderma pigmentosum (XP), but this was not explored further. Here we show that UVRAG plays an integral role in UV-induced DNA damage repair. It localizes to photolesions and associates with DDB1 to promote the assembly and activity of the DDB2-DDB1-Cul4A-Roc1 (CRL4(DDB2)) ubiquitin ligase complex, leading to efficient XPC recruitment and global genomic NER...
May 19, 2016: Molecular Cell
Chen Yan, Lan Luo, Shinji Goto, Yoshishige Urata, Chang-Ying Guo, Hanako Doi, Kaio Kitazato, Tao-Sheng Li
Autophagy, an essential catabolic pathway of degrading cellular components within the lysosome, has been found to benefit the growth and therapeutic resistance of cancer cells. In this study, we investigated the role of autophagy in the radio-sensitivity of cancer stem cells. By separating CD44+/CD133+ cancer stem cells from parental HCT8 human colorectal cancer cells, we found a significantly higher level of autophagy in the CD44+/CD133+ cells than in the parental cells. Exposure to 5 Gy of f-ray significantly damaged both CD44+/CD133+ cells and parental cells, but the radiation-induced damage did not differ between the groups...
April 25, 2016: Oncotarget
Chi Lu, Conghua Xie
Radiotherapy is an important treatment modality for esophageal cancer; however, the clinical efficacy of radiotherapy is limited by tumor radioresistance. In the present study, we explored the hypothesis that radiation induces tumor cell autophagy as a cytoprotective adaptive response, which depends on liver kinase B1 (LKB1) also known as serine/threonine kinase 11 (STK11). Radiation-induced Eca-109 cell autophagy was found to be dependent on signaling through the LKB1 pathway, and autophagy inhibitors that disrupted radiation-induced Eca-109 cell autophagy increased cell cycle arrest and cell death in vitro...
June 2016: Oncology Reports
C Alberti
No abstract text is available yet for this article.
2016: European Review for Medical and Pharmacological Sciences
Ting Liu, Xin Liu, Wenhua Li
Cancer is a disease caused by the abnormal proliferation and differentiation of cells governed by tumorigenic factors. Chemotherapy is one of the major cancer treatment strategies, and it functions by targeting the physiological capabilities of cancer cells, including sustained proliferation and angiogenesis, the evasion of programmed cell death, tissue invasion and metastasis. Remarkably, natural products have garnered increased attention in the chemotherapy drug discovery field because they are biologically friendly and have high therapeutic effects...
March 24, 2016: Oncotarget
Martin Ondrej, Lucie Cechakova, Kamila Durisova, Jaroslav Pejchal, Ales Tichy
Radiation-induced autophagy is believed to represent a radioprotective mechanism of cancer cells. Thus, its inhibition should support radiation treatment and increase its efficacy. On the other hand, there is evidence that radiation alone or in combination with various chemical agents can induce autophagy that results into increased cell death, especially within transformed apoptosis-resistant cells. In this paper, besides description of autophagic process and its relation to cancer and radiotherapy, we compared two contradictory radiosensitization approaches that employ inhibition and induction of autophagy...
May 2016: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
Rui Ding, Shengkan Jin, Kirk Pabon, Kathleen W Scotto
The ABC drug transporters, including ABCG2, are well known for their ability to efflux a wide spectrum of chemotherapeutic agents, thereby conferring a multidrug-resistant phenotype. However, studies over the past several years suggest that the ABC transporters may play additional role(s) in cell survival in the face of stress inducers that are not ABCG2 substrates (i.e., nutrient deprivation, ionizing radiation, rapamycin). The mechanism by which this occurs is largely unknown. In the present study, using several cancer cell lines and their ABCG2-overexpressing sublines, we show that cells overexpressing ABCG2 were more resistant to these stressors...
May 3, 2016: Autophagy
Michael I Koukourakis, Achilleas G Mitrakas, Alexandra Giatromanolaki
Glioblastoma is a unique model of non-metastasising disease that kills the vast majority of patients through local growth, despite surgery and local irradiation. Glioblastoma cells are resistant to apoptotic stimuli, and their death occurs through autophagy. This review aims to critically present our knowledge regarding the autophagic response of glioblastoma cells to radiation and temozolomide (TMZ) and to delineate eventual research directions to follow, in the quest of improving the curability of this incurable, as yet, disease...
March 1, 2016: British Journal of Cancer
Le-Ning Shao, Bao-Song Zhu, Chun-Gen Xing, Xiao-Dong Yang, Wu Young, Jian-Ping Cao
Tumor‑associated macrophages (TAMs), a major component of the tumor microenvironment, are crucial to the processes of tumor growth, infiltration and metastasis, and contribute to drug resistance. The importance of TAMs in radiation resistance of colorectal cancer remains unclear. To investigate the effects of autophagy regulation of TAMs on the radiosensitivity of colorectal cancer cells, the current study induced TAM formation from THP‑1 monocyte cells. Sequential treatment of THP‑1 cells with PMA for 72 h and human recombinant interleukin‑4 for 24 h was used to stimulate THP‑1 differentiation to TAMs...
March 2016: Molecular Medicine Reports
Longtao Huangfu, Haihai Liang, Guojie Wang, Xiaomin Su, Linqiang Li, Zhimin Du, Meiyu Hu, Yuechao Dong, Xue Bai, Tianyi Liu, Baofeng Yang, Hongli Shan
Ultraviolet radiation resistance-associated gene (UVRAG) is a well-known regulator of autophagy by promoting autophagosome formation and maturation. Multiple studies have implicated UVRAG in the pathogenesis of colorectal cancer. However, the mechanisms underlying the regulation of UVRAG are unclear. Here, we describe miR-183 as a new autophagy-inhibiting miRNA. Our results showed that induction of autophagy lead to down-regulation of miR-183 in colorectal cancer cells. And, over-expression of miR-183 resulted in the attenuation of rapamycin- or starvation-induced autophagy in cancer cells, whereas inhibition of endogenous miR-183 stimulated autophagy and apoptosis...
January 26, 2016: Oncotarget
Wolfgang Lilleby, Ljiljana Vlatkovic, Leonardo A Meza-Zepeda, Mona-Elisabeth Revheim, Eivind Hovig
INTRODUCTION: Renal cell carcinoma with the distinct type of t(6;11)(p21;q12) translocation (transcription factor EB) is a rare neoplasm. In the present case study, we show for the first time an autophagy signature in a patient with transcription factor EB renal cell carcinoma. We attempted to characterize the mutational and expressional features of a t(6;11)(p21;q12) renal cell carcinoma, in an effort to address the potential for molecular guidance of personalized medical decision for a case in this renal cell carcinoma category...
2015: Journal of Medical Case Reports
Haiqiu Liao, Yang Xiao, Yingbin Hu, Yangming Xiao, Zhaofa Yin, Liang Liu
The aberrant expression of microRNAs (miRNAs/miRs) has been found in numerous cancer types. miR-32 is an oncomiR in prostate cancer (PCa), however, the mechanisms by which miR-32 functions as a regulator of radiotherapy response and resistance in PCa are largely unknown. In the present study, it was found that DAB2 interacting protein (DAB2IP), the miR-32-dependent tumor-suppressor gene, was downregulated and induced autophagy and inhibited radiotherapy-induced apoptosis in PCa cells. miR-32 expression was upregulated or overexpressed in PCa, and miR-32 inhibited DAB2IP expression through a direct binding site within the DAB2IP 3' untranslated region...
October 2015: Oncology Letters
Mohamed Hassan, Denis Selimovic, Matthias Hannig, Youssef Haikel, Robert T Brodell, Mossaad Megahed
Melanoma is the most aggressive form of skin cancer. Disrupted intracellular signaling pathways are responsible for melanoma's extraordinary resistance to current chemotherapeutic modalities. The pathophysiologic basis for resistance to both chemo- and radiation therapy is rooted in altered genetic and epigenetic mechanisms that, in turn, result in the impairing of cell death machinery and/or excessive activation of cell growth and survival-dependent pathways. Although most current melanoma therapies target mitochondrial dysregulation, there is increasing evidence that endoplasmic reticulum (ER) stress-associated pathways play a role in the potentiation, initiation and maintenance of cell death machinery and autophagy...
November 20, 2015: World Journal of Experimental Medicine
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