Inhibition of cellular proliferation by knockdown of MARCH6 gene expression in breast cancer cells / 中南大学学报(医学版)

To investigate effects of MARCH6 gene knockdown on MCF-7 cell proliferation and cell cycle.
 Methods: 293T cells were transfected with MARCH6 shRNA lentivirus. Fluorescence microscope was used to observe and verify the transfection efficiency. The initial effect of the MARCH6 gene knockdown in MCF-7 cells was observed via fluorescence microscope. Real-time PCR and Western blot were used to detect the expression of MARCH6. MTT and BrdU assay were used to examine cell proliferation, and staining flow cytometry was used to analyze cycle distribution of MCF-7 cells.
 Results: MARCH6 shRNA lentivirus was successfully transfected and about 80% of the cells expressed green fluorescent in comparison of the control. About 90% of the cells showed green fluorescence. The mRNA and protein in MCF-7 cells were transcription and expression of protein was significantly decreased after the transfection of MARCH6 shRNA lentivirus accompanied by a decrease in MCF-7 cell proliferation (P<0.01). Flow cytometry showed that the cell cycles were inhibited at the G1 phase and the proliferation index was significantly reduced.
 Conclusion: Knockdown of MARCH6 gene by RNA interference inhibits the proliferation of MCF-7 cells, suggesting that the expression of MARCH6 promotes proliferation of breast cancer cells through regulation of the cell cycle.

Quantitative assessment of vasculature with DCE-MRI in nasopharyngeal carcinomas following radiotherapy and its value for efficacy evaluation / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the changes in quantitative kinetic parameters in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) during radiotherapy and their value for efficacy evaluation in patients with nasopharyngeal carcinoma (NPC).</p><p><b>METHODS</b>Twenty-four patients with NPC that had been pathologically confirmed as poorly differentiated squamous cell carcinoma underwent conventional MRI and DCE-MRI scans 1-2 days before radiotherapy (Pre-RT), during radiotherapy (RT 50 Gy), and upon completion of radiotherapy (RT 70 Gy). Based on the two-compartment model and using the arterial input function deconvolution technique, we calculated the quantitative kinetic parameters of DCE-MRI (K(trans), kep, and Ve) of the tumor tissues, examined the correlation between the tumor regression rate (RS0-50) and the parameters on Pre-RT and RT 50 Gy, and compared the parameters for RT 70 Gy among the groups with different prognosis.</p><p><b>RESULTS</b>The K(trans) value of the tumor tissue decreased after radiotherapy and showed a significant difference between Pre-RT and RT 70 Gy, but not between Pre-RT and RT 50 Gy. The kep value decreased and Ve value increased after radiotherapy. The tumor regression rate was found to be positively correlated with the K(trans) value for Pre-RT (P=0.005) but negatively with the K(trans) value for RT 50 Gy (P=0.001). During the follow-up for 3 years, 5 patients died and 3 patients had distant metastases. No statistical differences in K(trans), kep, or Ve were found between the groups with different prognosis.</p><p><b>CONCLUSIONS</b>The kinetic parameters in DCE-MRI, which vary significantly during radiotherapy, allow monitoring of tumor angiogenesis and vascular permeability and quantitative assessment of treatment efficacy for NPC. K(trans) value for Pre-RT and RT 50 Gy can serve as an indicator for early efficacy assessment of radiotherapy and for treatment adjustment, but its relation with the long-term outcomes awaits further study.</p>

Expression of GRP78 in the radiated survival subclones of nasopharyngeal carcinoma C666-1 cells / 中国医师杂志

Objective To investigate radio-sensitivity and expression of GRP78 protein in the survival subclones of nasopharyngeal carcinoma (NPC) C666-1 cells.Methods NPC C666-1 cells were first irradiated with X-ray at a large dose of 8Gy.Three survival subclones were selected and named as C666-1-R1, C666-1-R2, and C666-1-R3.The radio-sensitivity was analyzed for the radiated survival subclones and their parent control C666-1 cells with Methyl Thiazolyl Tetrazolium assay(MTT) and Trypan blue dye methods.The expression of GRP78 was analyzed for three survival subclones and control C666-1 with Western blot.Results After 6 Gy irradiation, the cell survival rate of three subclones was higher than that of the control cells, especially a significant difference for C666-1-R2 cells (P ＜ 0.05), which suggested a radioresistance in C666-1-R2 cells.Moreover, GRP78 expression in each subclone was significantly higher than that of parent C666-1 cells (P ＜ 0.05).Conclusions The irradiated-survival subclone C666-1-R2 was radio-resistant.GRP78 was overexpressed in the irradiated-survival subclones.GRP78 might be an ideal target for treatment of a nasopharyngeal carcinoma.

Intensity modulated radiation therapy for 90 untreated nasopharyngeal carcinoma / 中南大学学报(医学版)

OBJECTIVE@#To observe the clinical results and the toxicities of normal tissues in untreated nasopharyngeal carcinoma (NPC) treated with intensity modulated radiation therapy (IMRT).@*METHODS@#A total of 90 patients with untreated NPC received IMRT. According to the 1992 Fuzhou staging system, 3 patients were in stage I, 29 in stage II, 26 in stage III, and 32 in stage IVa. For IMRT,the prescription dose was 71.94-77.88 Gy/33f for the planning target volume of the gross tumor volume in the nasopharynx (PGTVnx); 69.96 Gy/33f for the positive neck lymph nodes (GTVnd); 60-66 Gy/33f for the planning target volume of the high risk regions (PTV1); and 50.4-56 Gy/28f for the planning target volume of the low risk regions (PTV2). Chemotherapy included concurrent and adjuvant protocols. The overall survival rate, local control rate, and distant metastasis-free survival rate were estimated by Kaplan-Meier method. Cox regression was used for multivariate analysis. Acute and 1ate toxicities were graded according to RTOG radiation morbidity scoring criteria.@*RESULTS@#The median follow-up time was 33 months (12-56 months). The 1-, 2-, 3- and 4-year survival rate was 97.8%, 90.6%, 86% and 80%; the local control tate was 98.8%, 97.5%, 92.1% and 77.4%; and the distant metastasis-free survival rate was 95.3%, 90.7%, 88.4% and 85.8%, respectively. The most serious acute toxicity was irradiated inflammation of mocosa with Grade 1 to 4 of 16.7%, 60%, 23.3% and 0, respectively. In the multivariate analysis, clinical stages were the prognostic factors for the survival rate. The most serious toxicity was salivary gland. The rate of grade xerostomia 1-year after the radiotherapy with Grade 1 to 4 was 18.1%, 9.6%, 0 and 0, respectively.@*CONCLUSION@#IMRT combined chemotherapy can improve the survival rate, and late adverse reaction is obviously decreased. Local recurrence and distant metastasis are the main reasons for low survival rate.

Expression and Clinical Significance of nm23-H_1 Protein in Nasopharyngeal Carcinoma / 中国医师杂志

Objective To explore the prognostic index for nasopharyngeal carcinoma (NPC). Methods The expression of nm23-H 1 protein in the tissue specimens of 115 NPC patients was detected by immunohistochemical S-P staining before radiotherapy. The 115 patients were treated in 1992～1994, underwent the whole radiotherapy, and were followed up for over 5 years. The association of nm23-H 1 protein expression with the clincal staging of NPC, radiosensitivity of tumor, survival rate of patients, and relapse and metastasis of carcinoma was analyzed. Results The positive rate of nm23-H 1 expression in NPC was 47.8%. The tumor clinical staging, lymph nodes metastasis, and patient survival rate were closely correlated with the low level expression of nm23-H 1 protein in NPC. Conclusion The low level expression of nm23-H 1 protein may be associated with the development and poor prognosis of NPC.