Identification of differential gene expression profiles of radioresistant lung cancer cell line established by fractionated ionizing radiation in vitro / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Radiotherapy plays a critical role in the management of non-small cell lung cancer (NSCLC). This study was conducted to identify gene expression profiles of acquired radioresistant NSCLC cell line established by fractionated ionizing radiation (FIR) by cDNA microarray.</p><p><b>METHODS</b>The human lung adenocarcinoma cell line Anip973 was treated with high energy X-ray to receive 60 Gy in 4 Gy fractions. The radiosensitivity of Anip973R and its parental line were measured by clonogenic assay. Gene expression profiles of Anip973R and its parental line were analyzed using cDNA microarray consisting of 21 522 human genes. Identified partly different expressive genes were validated by quantitative reverse transcription-polymerase chain reaction (Q-RT-PCR).</p><p><b>RESULTS</b>Fifty-nine upregulated and 43 downregulated genes were identified to radio-resistant Anip973R. Up-regulated genes were associated with DNA damage repair (DDB2), extracellular matrix (LOX), cell adhesion (CDH2), and apoptosis (CRYAB). Down-regulated genes were associated with angiogenesis (GBP-1), immune response (CD83), and calcium signaling pathway (TNNC1). Subsequent validation of selected eleven genes (CD24, DDB2, IGFBP3, LOX, CDH2, CRYAB, PROCR, ANXA1 DCN, GBP-1 and CD83) by Q-RT-PCR was consistent with microarray analysis.</p><p><b>CONCLUSIONS</b>Fractionated ionizing radiation can lead to the development of radiation resistance. Altered gene profiles of radioresistant cell line may provide new insights into mechanisms underlying clinical radioresistance for NSCLC.</p>

Preliminary study of the association between human thrombospondin and gastric cancer / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the possible role of human thrombospondin (hPWTSR) in gastric cancer and explore its potential to serve as the target for gastric cancer diagnosis and intervention.</p><p><b>METHODS</b>Using pLexA-hPWTSR as the bait, a premade pB42AD-based fetal brain cDNA library was constructed to identify the interacting proteins. The expression pattern of hPWTSR in gastric cancer tissues and a gastric cancer cell line was observed to investigate the correlation between hPWTSR expression and the biological behaviors of the tumor. The possibility of hPWTSR as a potential gastric cancer marker was evaluated.</p><p><b>RESULTS</b>Fifty-seven independent clones were isolated from 107 clones screened. Sequence analysis indicated that the 57 positive clones represented the products of 12 genes. A RT-PCR-based expression pattern revealed that the expression of hPWTSR in gastric cancer tissues and a gastric cancer cell line was lower than that in the corresponding normal tissues, but no mutations were identified by the subsequent sequence analysis.</p><p><b>CONCLUSIONS</b>hPWTSR interacts with adhesion-related proteins and tumor-related genes, and its expression is lowered in gastric cancer tissues and gastric cancer cell line. hPWTSR might play a role in gastric cancer development, especially in metastasis and might be used as a potential gastric cancer marker. The exact functions of hPWTSR and its potential clinical value still await further study.</p>

Radiosensitization of paclitaxel combined with radiation on nasopharygneal carcinoma cells (CNE-I) in vitro / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the radiosensitization of paclitaxel combined with radiation on nasopharygneal carcinoma cells( CNE-I) in vitro.</p><p><b>METHODS</b>Human CNE-I cells were used for this study. Clonogenic assay was used to determine the drug dose of IC10, IC50 and IC90 for CNE-I Cells. The cells treated with different concentration of paclitaxel for 24 hours before or after radiation (dose ranged from 0 - 10 Gy ) were used to evaluate the radiosensitizing effect of paclitaxel combined with radiation. DNA flow cytometry was performed to define the cell cycle characteristics of cell populations treated for 0, 2, 6, 12, 18, 24 h with 0.1 nmol/L, 0.5 nmol/L, 1.0 nmol/L, 2.5 nmol/L paclitaxel, respectively.</p><p><b>RESULTS</b>The dose of IC10, IC50 and IC90 for paclitaxel in CNE-I cells was 0.05 nmol/L, 1.0 nmol/L and 2.5 nmol/L, respectively. Paclitaxel treatment at concentration of 0.05 nmol/L and 1.0 nmol/L for 24 hours combined with X-ray irradiation before or after radiation showed radiosensitivity-enhansing effects in CNE-I cells. G2/M block was present when the drug concentrations were 2.5 nmol/L and 10.0 nmol/L, and it peaked at 18 hours.</p><p><b>CONCLUSION</b>With an optimal paclitaxel/radiation combination, paclitaxel may exert a radiosensitizing effect on CNE-I cells. The effect might be related to the G2/M block caused by paclitaxel.</p>

Multi-center phase II clinical trial of humanized anti-epidermal factor receptor monoclonal antibody h-R3 combined with radiotherapy for locoregionally advanced nasopharyngeal carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the efficacy and safty of the humanized anti-epidermal factor receptor monoclonal antibody h-R3 in combination with radiotherapy for locoregionally advanced nasopharyngeal carcinoma.</p><p><b>METHODS</b>Totally, 137 patients from 7 medical center around China were randomly divided into combined therapy group or control group. There was no difference in Karnofsky performance score between two groups. All patients in both groups received radical conventionally fractionated radiotherapy to the total dose of D(T) 70-76 Gy. For the combined therapy group, h-R3 was added at a dose of 100 mg i.v. weekly for 8 weeks started at the beginning of radiotherapy.</p><p><b>RESULTS</b>Of the 137 eligilbe patients, 70 were in the combined therapy group treated by h-R3 plus radiotherapy and 67 in the control group by radiotherapy alone. The intent-to-treat (ITT) population consisted of 130 patients, while the per-protocol (PP) population was composed of 126 patients. The efficacy was assessed respectively at three point of time: the end of treatment, the 5th- and 17th-week after treatment. The complete response (CR) of the combined therapy group was significantly higher than that of the control group in both ITT and PP (ITT: 65.63%, 87.50%, 90.63% versus 27.27%, 42.42%, 51.52%; PP: 67.21%, 90.16%, 93.44% versus 27.69%, 43.08%, 52.31%; P < 0.05, respectively). The most common h-R3-related adverse reactions were fever (4.3%), hypotension (2.9%), nausea (1.4%), dizziness (2.9%) and rash (1.4%), which could be reversible if treated properly. Radiotherapy combined with 100 mg h-R3 i. v. weekly was tolerable and did not aggravate the side effects of radiation. The quality of life in the combined therapy group was comparable to that in the control group.</p><p><b>CONCLUSION</b>This phase 1 multicenter clinical trial shows that h-R3 in combination with radiotherapy is effective and well-tolerated for the treatment of locoregionally advanced nasopharyngeal carcinoma.</p>

Radiobiological effects of fast neutron/photon mixed irradiation on nasopharyngeal cancer cell line CNE-1 / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the radiobiological effects of fast neutron/photon mixed irradiation on human cancer cell in vitro and to discuss the mechanism in relation with cell cycle and apoptosis, thus to provide experimental support for the further application of fast neutron radiotherapy of cancer.</p><p><b>METHODS</b>Exponentially growing human nasopharyngeal cancer cell line CNE-1 was irradiated in vitro with 35 MeV p-->Be fast neutron and 6 MV-X ray in grading doses (0 cGy, 40 cGy, 80 cGy, 120 cGy, 160 cGy, 240 cGy, 320 cGy and 400 cGy for neutron, and 0 cGy, 100 cGy, 200 cGy, 300 cGy, 400 cGy, 600 cGy, 800 cGy and 1000 cGy for X ray). Clonogenic assay was performed, and relative biological effectiveness (RBE) of fast neutron was determined with D(10) by means of cell survival curves. Isoeffective doses of 35 MeV p-->Be fast neutron and 6 MV-X ray were obtained according to the RBE. The cells were assigned into two irradiation regimens, (1) the one-week-fractionation regimen, which adopted the radiation pattern of X x 5, N x 2 and X-N-X-X-N. After irradiation the clonogenic assay was performed to compare their survival fractions; (2) the two-dose regimen, with the radiation pattern of X + N, N + X and X + X. Flow cytometry was done at different time points after irradiation to analyze cell cycle distribution and apoptosis. Fast neutron dose was delivered on Tuesday and Friday, and all the other irradiation intervals were 24 h.</p><p><b>RESULTS</b>The RBE of fast neutron to X ray in CNE-1 cells according to the D(10) ratio was 2.40. The neutron isoeffective dose for a single dose of 200 cGy of 6 MV-X ray was approximately 80 cGy. In clonogenic assay, the cell survival fractions were significantly lower in X-N-X-X-N group (0.0079) than those in X x 5 (0.018) and N x 2 (0.017) groups. The flow cytometry suggested a higher percentage of apoptotic cells after mixed irradiation, and different sequence of X ray and neutron irradiations caused varying changes in cell cycle arrest.</p><p><b>CONCLUSION</b>Mixed irradiation of fast neutron and X ray showed a synergic effect in vitro on CNE-1 cell killing. Cell cycle arrest and apoptosis may play some role in the radiation damage repair mechanisms of mixed beam irradiation.</p>

Radiosensitivity detected by "comet" assay in two human tumor cell lines / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the value of the "comet" assay in detecting the radiosensitivity in human tumor cell lines.</p><p><b>METHODS</b>The radiation-induced primary DNA damage and repair were detected by the comet assay in CNE-1 and 973 cell lines. The tail moment was used as the end point, to quantitate the primary DNA damage and subsequent repair ability. The cell-survival curve was plotted by the classical colony assay, to detect the D(0) value and Dq value. The results from the above two assays were compared.</p><p><b>RESULTS</b>1. With the increment of irradiation doses, under the same experimental condition, the radiation-induced primary DNA damage was more severe in CNE-1 cells than in 973 cells (P < 0.01). From the cell-survival curves, the D(0) value was 1.631 and 1.822 in CNE-1 and CNE-1 973 cells respectively, indicating that CNE-1 cells were more sensitive to irradiation than 973 cells. The radiosensitivity detected by comet assay and by colony assay in the two cell lines tended to be consistent. 2. The half-repair time of 973 and CNE-1 cell line was 33 min and 41 min detected by comet assay, which indicats that the ability of DNA damage and repair in CNE-1 cells was weaker than in 973 cells. The Dq value of the cell survival curve was 2.152 for 973 and 0.626 for CNE-1 cell line detected by the colony assay, which indicates that the sublethal damage repair in 973 cells being much faster than in CNE-1 cells. The repair ability reflected by the results in the two cell lines was consistent.</p><p><b>CONCLUSION</b>The radiosensitivities reflected by the results of the primary DNA damage and repair detected by both comet assay and colony assay in CNE-1 and 973 cells are consistent. It suggests that comet assay is a good method for detecting the radiosensitivity of tumor cells.</p>