miR-29b Reduces Cisplatin Resistance of Gastric Cancer Cell by Targeting PI3K/Akt Pathway / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the regulatory effect of miR-29b on gastric cells' resistance to cisplatin.</p><p><b>METHODS</b>The expression of miR-29b in gastric cancer cell line treated with cisplatin concentration gradient was detected using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) and Western blotting. CCK8 was used to measure the cell viability after cisplatin treatment in condition of miR-29b knock-down and overexpression.</p><p><b>RESULTS</b>The expression of miR-29b was significantly upregualted by cisplatin treatment,while its target gene AKT2 was downregulated. The up-regulation of miR-29b enhanced the sensitivity of gastric cancer cells to cisplatin,while the knock-down of miR-29b enhanced the cisplatin resistance. Rescue experiments demonstrated that the miR-29b might regulate cisplatin resistance of gastric cancer cell by targeting PI3K/Akt pathway. The expressions of the other two members of miR-29 family, miR-29a/c, were promoted by cisplatin treatment,but they had no significant effect on gastric cancer cell's resistance to cisplatin.</p><p><b>CONCLUSION</b>miR-29b can enhance the sensitivity of S gastric cancer cell by directly targeting PI3K/Akt pathway.</p>

Clinical study on the changes of the tumor target volume and organs at risk in helical tomotherapy for nasopharyngeal carcinoma / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Helical tomotherapy (HT) is a new image-guided intensity-modulated radiation therapy (IMRT). The aim of this study was to evaluate the changes in the target volume and organs at risk (OARs) of patients with nasopharyngeal carcinoma (NPC) during helical tomotherapy.</p><p><b>METHODS</b>Forty-three patients with NPC and treated via HT from March 2008 to January 2010 were reviewed retrospectively. Repeated CT scanning and plan adaptation were conducted at the 20th fraction during radiotherapy. The volumetric differences between the two scans were evaluated for nasopharyngeal tumor and retro-pharyngeal lymph nodes (GTVnx), neck lymph nodes (GTVnd), and parotid glands, as well as the axial diameter of the head.</p><p><b>RESULTS</b>The median interval between the two scans was 25 days (23 - 28 days). The volumetric decrease in GTVnx was 30.1% (median, 29.8%) and in GTVnd 41.6% (median, 45.9%). The variation in the GTVnd volume was correlated with the weight loss of the patient. The volume of the left parotid gland decreased by 35.5% (median, 33.4%) and of the right parotid glands decreased by 36.8% (median, 33.5%). The axial diameter of the head decreased by 9.39% (median, 9.1%).</p><p><b>CONCLUSIONS</b>The target volume and OARs of patients with NPC varied considerably during HT. These changes may have potential dosimetric effects on the target volume and/or OARs and influence the clinical outcome. Repeated CT scanning and replanning during the HT for NPC patients with a large target volume or an obvious weight loss are recommended.</p>

Management of oral mucositis in patients with head and neck cancer receiving chemoradiotherapy and/or molecular targeted therapy / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the prevalence and treatment of oral mucositis caused by concurrent chemoradiotherapy and/or molecular targeted therapy in the patients with advanced squamous cell carcinoma of the head and neck.</p><p><b>METHODS</b>A retrospective study of the incidence and treatment of oral mucositis was performed in 179 patients (155 male and 24 female;124 patients at stage III and 55 patients at stage IV) receiving concurrent chemotherapy and (or) molecular targeted therapy between November 2007 and November 2010. Grade I, II, III and IV oral mucositis occurred respectively in 49, 50, 67 and 13 patients. All the patients received oral mucositis prophylaxis. After the occurrence of oral mucositis, conventional treatment of mucositis combined with quinolone antibiotics were applied.</p><p><b>RESULTS</b>Of the patients, 99 patients with grade I or II and 4 patients with grade III oral mucositis were effectively managed by conventional treatment; 76 patients with grade III or IV oral mucositis were also significantly controled by conventional treatment plus antibiotics. After the treatments, all patients with oral mucositis were under control, with the decrease in the grade of oral mucositis, the reduction of oral pain and the improvement in ability to eat. None of them had radiation treatment breaks.</p><p><b>CONCLUSIONS</b>Combined modality therapy can effectively control chemoradiation-induced oral mucositis in patients with head and neck squamous cell carcinoma, grade I and II oral mucositis were cured by conventional treatment and quinolone antibiotics play a key role in the treatments for grade III and IV oral mucositis.</p>

Dosimetric comparison between helical tomotherapy and intensity-modulated radiation therapy plans for non-small cell lung cancer / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Helical tomotherapy (HT) is a new image-guided intensity-modulated radiation therapy (IMRT) technique. It is reported that HT plan for non-small-cell lung cancer (NSCLC) can give better dose uniformity, dose gradients, and protection for the lung than IMRT plan. We compared the dosimetric characteristics of HT for NSCLC with those of conventional IMRT to observe the superiority of HT.</p><p><b>METHODS</b>There was a comparative case series comprising 10 patients with NSCLC. Computed tomographic (CT) images of delineated targets were transferred to the PrecisePlan planning system (IMRT) and Tomo planning system (HT). The prescription doses were 70 Gy/33F for the gross tumor volume (GTV) and the visible lymph nodes (GTVnd), and 60 Gy/33F for the clinical target volume (CTV) and the clinical target volume of the visible lymph nodes (CTVnd). The dose restrictions for organs at risk were as follows: the maximum dose to spinal cord ≤ 45 Gy, V20 to the total lungs < 30%, V50 to the heart < 50%, and V55 to the esophagus < 50%. Both plans were evaluated by means of the dose coverage of the targets, dose-volume histograms (DVHs), and other dosimetric indices.</p><p><b>RESULTS</b>The dose coverage, conformity, and homogeneity of the targets' volumes were found to be satisfactory in both plans, but the homogeneity of the HT plan was better than that of IMRT. The high-dose radiation volume (V20-V30) to the lung and the mean lung dose (MLD) decreased (P < 0.05), but the low-dose radiation volume (V5-V10) increased slightly in the HT plan (P > 0.05). The maximum doses to the spinal cord, heart, esophagus and trachea in the HT plan were lower than those in the IMRT plan, but the differences were not statistically significant.</p><p><b>CONCLUSIONS</b>The HT plan provids better dose uniformity, dose gradients, and protection for the organs at risk. It can reduce the high-dose radiation volume for lung and the MLD, but may deliver a larger lung volume of low-dose radiation.</p>