Non-small cell lung cancer (NSCLC) accounts for about 85% of all lung cancer cases. The pathogenesis of NSCLC involves complex gene networks that include different types of non-coding RNAs, such as long non-coding RNAs (lncRNAs). The role of lncRNAs in NSCLC is gaining an increasing interest as their function is being explored in various human cancers. Recently, a new oncogenic lncRNA, LINC00152 (cytoskeleton regulator RNA (CYTOR)), has been identified in different tumor types. In NSCLC, the high expression of LINC00152 in tumor tissue and peripheral blood samples has been shown to be associated with worse prognoses of NSCLC patients. Overexpression of LINC00152 has been confirmed to promote the proliferation, invasion, and migration of NSCLC cells in vitro, as well as increase tumor growth in vivo. This review discusses the role of LINC00152 in NSCLC.
Apoptosis ; Biomarkers, Tumor/blood* ; Carcinoma, Non-Small-Cell Lung/radiotherapy* ; Cell Cycle Checkpoints ; Computational Biology ; Epithelial-Mesenchymal Transition ; Humans ; Lung Neoplasms/radiotherapy* ; Prognosis ; RNA, Long Noncoding/physiology* ; Radiation Tolerance

BACKGROUNDOsteopontin (OPN) is a secreted phosphoglycoprotein (SSP) that is overexpressed in a variety of tumors and was regarded as a molecular marker of tumors. In this study, we intended to demonstrate the role of OPN in human breast cancer cell line MDA-MB-231.

METHODSRecombinant plasmid expressing small interfering RNA (siRNA) specific to OPN mRNA was transfected into MDA-MB-231 cells to generate the stable transfected cell line MDA-MB-343, and the empty plasmid tansfected cells (MDA-MB-neg) or wildtype MDA-MB-231 cells were used as control cells respectively. Expression of OPN, hypoxia inducible factor-1 (HIF-1) and vascular endothelial growth factor (VEGF) proteins was analyzed by Western blotting analysis. The radiosensitivity of cells was determined by detecting cell apoptosis, cell proliferation and cell senescence.

RESULTSHIF-1 and VEGF proteins in MDA-MB-343 cells were significantly downregulated upon the efficient knockdown of OPN expression under either hypoxia or normoxia environment. Moreover, expression of OPN protein was upregualted upon hypoxic culture. Stable OPN-silencing also decreased cell invasion, increased cell apoptosis and cell senescence, as well as reduced clonogenic survival, resulting in increase radiation tolerance.

CONCLUSIONSSuppression of OPN gene expression can enhance radiosensitivity and affect cell apoptosis in breast cancer cells. OPN seems to be an attractive target for the improvement of radiotherapy.

Breast Neoplasms ; genetics ; metabolism ; Cell Line, Tumor ; Female ; Gene Expression Regulation, Neoplastic ; drug effects ; genetics ; Humans ; Hypoxia-Inducible Factor 1 ; genetics ; metabolism ; Osteopontin ; genetics ; metabolism ; RNA, Small Interfering ; Radiation Tolerance ; genetics ; physiology ; Reverse Transcriptase Polymerase Chain Reaction ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

OBJECTIVETo assess the correlation of O6-methylguanine-DNA methyltransferase (MGMT) to radiation sensitivity of nasopharyngeal carcinoma (NPC).

METHODSEighty randomly selected NPC patients were divided into high (+/++, n=62) and low (-/+/+, n=18) MGMT groups according to the results of MGMT detection using immunohistochemistry. All the patients received irradiation with external beam radiotherapy, and the radiation sensitivity of NPC was analyzed after the irradiation.

RESULTSThe rates of high and low radiation sensitivity were 83.3% and 16.7% in low MGMT group, respectively, showing significant differences from those of the high MGMT group (45.2% and 54.8%, respectively, chi(2)=4.393, P=0.036).

CONCLUSIONThe content of MGMT correlates to the radiation sensitivity of NPC and may serve as valuable indicators for predicting the radiation sensitivity of NPC.

Adolescent ; Adult ; Aged ; Carcinoma, Squamous Cell ; enzymology ; radiotherapy ; DNA Modification Methylases ; blood ; DNA Repair Enzymes ; blood ; Female ; Humans ; Male ; Middle Aged ; Nasopharyngeal Neoplasms ; enzymology ; radiotherapy ; Radiation Tolerance ; physiology ; Tumor Suppressor Proteins ; blood ; Young Adult

Apurinic/apyrimidinic endonuclease/redox factor-1 (APE/Ref-1), as a type of multifunctional protein, plays an essential role in the base excision repair (BER) pathway, which is responsible for the repair of DNA caused by oxidative and alkylation damage. As importantly, APE/Ref-1 also functions as a redox factor maintaining transcription factors in an active reduced state. APE/Ref-1 stimulates the DNA-binding activity of numerous transcription factors that are involved in cancer promotion and progression, such as AP-1 (Fos/Jun), NF-kappaB, HIF-1alpha, p53, and others. Based on the structures and functions of APE1/Ref-1, we will provide an overview of its activities and explore the budding clinical use of this protein as a target in cancer treatment, and propose that APE/Ref-1 has a great potential for application in clinical research.
Apoptosis ; DNA Repair ; genetics ; DNA-(Apurinic or Apyrimidinic Site) Lyase ; antagonists & inhibitors ; genetics ; metabolism ; physiology ; Drug Delivery Systems ; Drug Resistance, Neoplasm ; Humans ; Neoplasms ; drug therapy ; metabolism ; radiotherapy ; Oxidation-Reduction ; Polymorphism, Single Nucleotide ; Precancerous Conditions ; metabolism ; Radiation Tolerance

OBJECTIVETo investigate the expressions of protein kinase C (PKC) isoforms in X-ray-exposed HepG2 cells and identify the PKC isoforms that induce radioresistance in HepG2 cells.

METHODSCultured HepG2 cells were divided into control group and 6 Gy radiation group for corresponding treatments. The fluorescence intensity (FI) and the percentage of positive cells were determined using flow cytometry.

RESULTSThe FI of PKCalpha and PKCdelta were 2.28 and 5.05 in the radiation group, respectively, significantly higher than those in the control group (P<0.05). The percentages of PKCalpha- and PKCdelta -positive cells were significantly higher in the radiation group than in the control group (P<0.05). The FI and the percentages of PKC zeta, gamma, epsilon, zeta positive cells were rather low and showed no significant differences between the two groups (P>0.05); PKCbeta expression was not detected in the two groups of cells. The apoptosis rates of the control and radiation groups were 1.73% and 20.90%, respectively.

CONCLUSIONPKCalpha and PKCdelta may be involved in protecting HepG2 cells from radiation-induced apoptosis.

Apoptosis ; physiology ; radiation effects ; Hep G2 Cells ; Humans ; Isoenzymes ; classification ; metabolism ; Protein Kinase C-alpha ; metabolism ; Protein Kinase C-delta ; metabolism ; Radiation Tolerance ; Signal Transduction ; drug effects ; physiology

Glioblastomas (GBMs) are highly lethal primary brain tumors. Despite current therapeutic advances in other solid cancers, the treatment of these malignant gliomas remains essentially palliative. GBMs are extremely resistant to conventional radiation and chemotherapies. We and others have demonstrated that a highly tumorigenic subpopulation of cancer cells called GBM stem cells (GSCs) promotes therapeutic resistance. We also found that GSCs stimulate tumor angiogenesis by expressing elevated levels of VEGF and contribute to tumor growth, which has been translated into a useful therapeutic strategy in the treatment of recurrent or progressive GBMs. Furthermore, stem cell-like cancer cells (cancer stem cells) have been shown to promote metastasis. Although GBMs rarely metastasize beyond the central nervous system, these highly infiltrative cancers often invade into normal brain tissues preventing surgical resection, and GSCs display an aggressive invasive phenotype. These studies suggest that targeting GSCs may effectively reduce tumor recurrence and significantly improve GBM treatment. Recent studies indicate that cancer stem cells share core signaling pathways with normal somatic or embryonic stem cells, but also display critical distinctions that provide important clues into useful therapeutic targets. In this review, we summarize the current understanding and advances in glioma stem cell research, and discuss potential targeting strategies for future development of anti-GSC therapies.
Biomarkers, Tumor ; metabolism ; Brain Neoplasms ; metabolism ; pathology ; therapy ; Cell Differentiation ; Cell Hypoxia ; Drug Resistance, Neoplasm ; Gene Expression Regulation ; Glioblastoma ; metabolism ; pathology ; therapy ; Humans ; MicroRNAs ; physiology ; Neoplastic Stem Cells ; metabolism ; pathology ; Neovascularization, Pathologic ; Radiation Tolerance ; Signal Transduction ; Transcription Factors ; metabolism

The low dose hyper-radiosensitivity (HRS) in human lung cancer cell line A549 was investigated, the changes of ATM kinase, cell cycle and apoptosis of cells at different doses of radiation were observed, and the possible mechanisms were discussed. A549 cells in logarithmic growth phase were irradiated with (60)Co gamma-rays at doses of 0-2 Gy. Together with flow cytometry for precise cell sorting, cell survival fraction was measured by means of conventional colony-formation assay. The expression of ATM1981Ser-P protein was examined by Western blot 1 h after radiation. Apoptosis was detected by Hoechst 33258 fluorescent staining, and Annexin V-FITC/PI staining flow cytometry 24 h after radiation. Cell cycle distribution was observed by flow cytometry 6, 12 and 24 h after radiation. The results showed that the expression of ATM1981Ser-P protein was observed at 0.2 Gy, followed by an increase at >0.2 Gy, and reached the peak at 0.5 Gy, with little further increase as the dose exceeded 0.5 Gy. Twenty-four h after radiation, partial cells presented the characteristic morphological changes of apoptosis, and the cell apoptosis curve was coincident with the survival curve. As compared with control group, the cell cycle almost had no changes after exposure to 0.1 and 0.2 Gy radiation (P>0.05). After exposure to 0.3, 0.4 and 0.5 Gy radiation, G(2)/M phase arrest occurred 6 and 12 h after radiation (P<0.05), and the ratio of G(2)/M phase cells was decreased 24 h after radiation (P<0.05). It was concluded that A549 cells displayed the phenomenon of HRS/IRR. The mode of cell death was mainly apoptosis. The activity of ATM and cell cycle change may take an important role in HRS/IRR.
Cell Cycle Proteins/genetics ; Cell Cycle Proteins/metabolism ; Cell Cycle Proteins/physiology ; Cell Line, Tumor ; DNA-Binding Proteins/antagonists & inhibitors ; DNA-Binding Proteins/metabolism ; DNA-Binding Proteins/*physiology ; Dose-Response Relationship, Radiation ; Lung Neoplasms/*pathology ; Protein-Serine-Threonine Kinases/*metabolism ; Radiation Dosage ; Radiation Tolerance/*physiology ; Tumor Suppressor Proteins/metabolism

OBJECTIVE: To determine the effect of Ad-E1A gene therapy on in vivo radiosensitivity to nasopharyngeal carcinoma. METHODS: CNE-2Z cells (2 x 10(5)) were subcutaneously injected into nude mice to develop tumor (1-3 mm) 6 days later. The tumor-bearing mice were then randomly divided into 6 groups (10 mice per group) for PBS treatment or treatment with radiotherapy, Ad-E1A, or Ad-beta-gal alone or radiotherapy in combination with Ad-E1A or Ad-beta-gal. The mice were treated with Ad-E1A or Ad-beta-gal (5 x 10(9) plaque forming units) by intratumoral injection twice weekly for 2 weeks at beginning of week 2. The mice treated with radiotherapy in combination with Ad-E1A or Ad-beta-gal received 2 Gy radiotherapy daily for 5 days following the first week of treatment with Ad-E1A or Ad-beta-gal. Control mice received PBS therapy or radiotherapy only after tumor cells were injected. When the size of tumor exceeded 2 cm, the mice were killed and the tumors underwent immunohistochemical analysis for VEGF and CD34 expression and TUNEL assay for apoptosis. RESULTS: The growth delay time was longest in the Ad-E1A plus radiotherapy group. Tumors treated with Ad-E1A plus radiotherapy were 4.7-fold smaller than those treated with radiotherapy alone and 5.3-fold smaller than those treated with Ad-E1A alone. The survival rate of tumor-bearing mice treated with Ad-E1A plus radiotherapy was significantly higher than that of other treatment groups. The vessel density and the VEGF expression were significantly lower in tumors treated with Ad-E1A plus radiotherapy than those treated with radiotherapy alone, Ad-E1A alone, Ad-beta-gal alone, or Ad-beta-gal plus radiotherapy (P<0.01). TUNEL staining revealing apoptosis can be detected in the Ad-E1A group, radiotherapy group, Ad-E1A plus radiotherapy group, and more apoptosis can be detected in tumors treated with Ad-E1A plus radiotherapy than those of other treatment groups. CONCLUSION E1A gene therapy can effectively enhance the nasopharyngeal carcinoma sensitivity to the radiotherapy by down-regulating VEGF expression and inducing apoptosis.
Adenovirus E1A Proteins ; biosynthesis ; genetics ; Animals ; Apoptosis ; physiology ; Cell Line, Tumor ; Genetic Therapy ; methods ; Humans ; Mice ; Mice, Nude ; Nasopharyngeal Neoplasms ; blood supply ; pathology ; radiotherapy ; Neoplasm Transplantation ; Radiation Tolerance ; genetics ; Random Allocation ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

AC133 Antigen ; Animals ; Antigens, CD ; metabolism ; Cell Differentiation ; Cell Proliferation ; Drug Resistance, Neoplasm ; Glioma ; pathology ; Glycoproteins ; metabolism ; Humans ; Neoplastic Stem Cells ; metabolism ; pathology ; physiology ; Neovascularization, Pathologic ; etiology ; pathology ; Peptides ; metabolism ; Radiation Tolerance

BACKGROUNDThe second mitochondria-derived activator of caspases (Smac) is a novel proapoptotic gene, which plays an important role in the apoptosis-inducing effects of irradiation on tumor cells. The purpose of this study was to investigate the effects of extrinsic Smac gene transfer and its over-expression in radiotherapeutic sensitivities of cervical cancer cells.

METHODSAfter the Smac gene was transferred into the cervical cancer cell line HeLa, subcloned cells were obtained by persistent G418 selection. Cellular Smac gene expression was detected by RT-PCR and Western blot, while in vitro cell viabilities were detected by trypan blue staining assay. After treatment with X-ray irradiation, cellular radiotherapeutic sensitivities were investigated by tetrazolium bromide colorimetry. Cellular apoptosis and its rate were determined by electronic microscopy, annexin V-FITC and propidium iodide staining flow cytometry. The expression and activities of cellular caspase-3 were assayed by Western blot and colorimetry.

RESULTSSmac mRNA and protein levels in HeLa/Smac cells and the selected subclone cell line of cervical cancer were significantly higher than those of HeLa (P < 0.01). There was no significant difference in cellular viabilities between them (P > 0.05). However, after irradiation with 8 Gy X-ray, growth activities of HeLa/Smac were reduced by 22.42% (P < 0.01). When compared with those of HeLa, partial HeLa/Smac cells presented characteristic morphological changes of apoptosis under electronic microscope, with higher apoptosis rates (16.4% vs. 6.2%, P < 0.01); the caspase-3 expression levels in HeLa/Smac cells were improved significantly (P < 0.01), while its activities were increased by 3.42 times (P < 0.01).

CONCLUSIONSStable transfer of the extrinsic Smac gene and its over-expression in cervical cancer cell line could significantly enhance the expression and activities of cellular caspase-3 and ameliorate apoptosis-inducing effects of irradiation on cancer cells, which was a novel strategy to improve radiotherapeutic effects on cervical cancer.

Apoptosis ; radiation effects ; Carrier Proteins ; genetics ; physiology ; Caspase 3 ; Caspases ; metabolism ; Female ; Gene Transfer, Horizontal ; HeLa Cells ; Humans ; Intracellular Signaling Peptides and Proteins ; Mitochondrial Proteins ; genetics ; physiology ; Radiation Tolerance ; Uterine Cervical Neoplasms ; drug therapy ; enzymology ; pathology