Observation of radiobiological characteristics in a HepG2 cell line with mitochondrial DNA deletion / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the radiobiological characteristics of a HepG2 cell line with mitochondrial DNA (mtDNA) deletion.</p><p><b>METHODS</b>HepG2 cells were cultured in a medium containing ethidium bromide, acetylformic acid and uracil. The HepG2 cell line with mtDNA deletion (ρ(0)HepG2 cells) were acquired after 30 subcultures by limited dilution cloning. The cell survival was then observed in the absence of acetylformic acid and uracil, and the total mtDNA deletion in the cells was confirmed by PCR. The radiosensitivity of HepG2 and ρ(0)HepG2 cells was evaluated by exposure to gradient doses of 6 MV X ray irradiation. The cell apoptosis was assessed following a 2 Gy X-ray exposure with Hochest33342 staining, and the invasiveness of ρ(0)HepG2 cells was measured by Transwell assay.</p><p><b>RESULTS</b>HepG2 cells could survive 30 subcultures in the presence of ethidium bromide, and massive cell death occurred after removal of acetylformic acid and uracil from the medium. PCR confirmed total mtDNA deletion from ρ(0)HepG2 cells, whose α/β value was significantly lower than that of HepG2 cells. ρ(0)Hep-G2 cells showed an obviously lowered cell apoptosis rate following X-ray exposure with enhanced cell invasiveness.</p><p><b>CONCLUSION</b>HepG2 cells can be induced by ethidium bromide into ρ(0)HepG2 cells with an increased radiation resistance, anti-apoptosis ability and cell invasiveness.</p>

Relationship between tumor differentiation and related pathologic factors in Esophago-gastric junction adenocarcinoma / 中国综合临床

Objective To investigate the relationship between the tumor differentiation and the related pathologic factors in Esophago-gastric junction adenocarcinoma. Methods The pathological data from 163 patients of Esophago-gastric junction adenocarcinoma underwent radical surgical resections were randomly divided two groups (group1: well-differentiated,group2: poor-differentiated). The composition of N stages,T stages,morphological type and vessel carcinoma embolus were compared between the two groups ,respectively. The tumor sizes and the number of metastases lymph nodes were compared between the two groups. Results The cases with lower N stages or T stages in group1 were dominant(T1 and T2:55. 74%,N1 and N2:75.41%). Oppositely,those with higher N stages or T stages were dominant(T3 and T4:59.81%,N1 and N2:57.85%)in group 2. The differences were significant Incidence of vessel carcinoma embolus was 44. 26%(27/61)in group 1 and 63. 73%(65/102)in group 2,with a significant difference. There was no significant difference for morphological type in the two groups. The tumor sizes and the number of metastases lymph was 4. 27 ±2. 00 cm and 4. 15 ±5.27 respectively in group 1 ,and 5. 87 ± 3. 26 cm and 8. 80 ± 7.65 respectively in group 2. The differences were significantly different(Ps ＜ 0. 01).Conclusions The tumor differentiation has significant effect on N stages,T stages,vessel carcinoma embolus,tumor size and the number of metastases lymph nodes in Esophago-gastric junction adenocarcinoma.

Treatment of gemcitabine combined with nedaplatin and paclitaxel for patients with metastatic cisplatin-resistant nasopharyngeal carcinoma / 肿瘤研究与临床

Objective To assess the short-term effects and adverse reactions of combination regimen of gemcitabine, nedaplatin and paclitaxel for patients with metastatic cisplatin-resistant nasopharyngeal carcinoma (NPC). Methods A total of 15 patients with metastatic cisplatin-resistant NPC were enrolled. All patients were treated with a combination regimen including gemcitabine with 1000 mg/m2 on day 1st and 8th, nedaplatin with 70 mg/m2 on day 1st and paclitaxel with 135 mg/m2 on day 1st, repeated every 21 days. Response was evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria 3.0. Results The overall response rate was 40.0 %, with a complete response rate of 6.7 % (1/15) and a partial response rate of 33.3 % (5/15). Six patients (40.0 %) had stable disease and 3 patients (20.0 %) had progressive disease. The median time to progression (TTP) was 4.7 months and the median overall survival was 6.3 months. Hematological toxicities were the adverse reaction with 40.0 % of leucopenia, 6.7 % of anemia and 20.0 % thrombocytopenia. One patient needed for platelet transfusion. Other adverse reactions were mild. Conclusion The combination regimen of gemcitabine, nedaplatin and paclitaxel is feasible as second-line chemotherapy in patients with metastatic cisplatin-resistant NPC.

Three-dimensional conformal hypofractionated radiotherapy for non-small-cell lung cancer / 中国癌症杂志

Background and purpose:The local tumor control rate of non-small-cell lung cancer treated with conventionally fractionated radiotherapy is low.Hypofractionated radiotherapy performed by conformal irradiation techniques can improne the local control rate.But further studies for appropriate fraction dose and toxicity for hypofractionation should be done.The purpose of this study was to prospectively evaluate the safety and efficacy of three-dimensional conformal hypofractionated radiotherapy for non-small-cell lung cancer(NSCLC).Methods:According to the dose-volume histogram(DVH) V_(20), patients were divided into three groups:① V_(20)≤20%,②20%30%,grade Ⅲ RP was observes in 2 of 5 patients and grade Ⅳ RP in 1 patient who died of lung function failure.No grade≥Ⅲ radiation esophagitis was observed.25 patients were evaluated with 8 complete responses,13 partial responses,3 stable diseases and 1 progressive disease.Conclusions:For three-dimensional conformal hypofractionated radiotherapy V_(20) level should be controlled below 30%,the treatment plan with V_(20)≥30% should be changed to palliative treatment.More studies are needed to confirm its efficacy.

~(18)F-deoxyglucose-PET in the detection of recurrence in head and neck cancer / 中华放射肿瘤学杂志

Objective To evaluate 18 F deoxyglucose positron emission tomography (FDG PET) in the detection of suspicious recurrence in head and neck cancers , as compared with CT/MRI imaging. Methods Thirty seven patients with clinically suspicious recurrences in head and neck cancers underwent FDG PET, with 34 checked with CT/MRI imaging. The final diagnosis of recurrence were proved by pathology or clinical following up. Results FDG PET detected recurrence successfully in 32 of 37(86.5%) patients with 3 false positives and 2 false negatives. The FDG PET sensitivity, specificity and accuracy in defining local recurrence were 91.7%, 76.9%, 86.5%, respectively; and those of CT/MRI were 68.2%, 75.0%, 61.8%, respectively. Conclusion In comparison with CT/MRI, FDG PET possesses a higher accuracy in detecting recurrence in head and neck cancers.