Inhibitory effect of Oridonin injection on heterotransplanted gastric adenocarcinoma in nude mice and its mechanism / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the inhibitory effect of Oridonin injection on heterotransplanted tumors of human gastric adenocarcinoma cell line BGC823 cells in nude mice and explore its mechanism.</p><p><b>METHODS</b>Heterotransplanted models of human gastric adenocarcinoma cell line BGC823 cells in nude mice were established. They were divided at random into three groups as control group, low-dose group and high-dose group. The Oridonin solution at concentration of 37.5 mg x kg(-1 x d(-1) and 75 mg x kg(-1) x d(-1) were injected to the mice in low-dose group and high-dose group, respectively, and 0.9% sodium chloride was injected to the mice of control group per day for 10 days sequentially. The mice of the three groups were sacrificed at 11th day after the first injection of Oridonin. The tumor weight of the sacrificed mice was measured. Morphological and ultrastructural examinations of the tumors were carried out by light and electron microscopy. The expression of bcl-2, Bax, Fas and FasL was detected by immunohistochemistry.</p><p><b>RESULTS</b>Oridonin injection showed a suppressive effect on the growth of heterotransplanted tumors in the nude mice. The tumor growth inhibition rates were 48.5% and 70.7% in the low-dose and high-dose groups, respectively. The morphological study demonstrated that tumor cells displayed a typical appearance of apoptosis. The expression of bcl-2 was down-regulated, while Bax, Fas and FasL were up-regulated.</p><p><b>CONCLUSION</b>Oridonin can markedly inhibit the growth of heterotransplanted human gastric adenocarcinoma in nude mice. It was due, at least in part, to the induction of apoptosis in cancer cells.</p>

The promotive effects of N-nitrosopiperidine on the malignant transformation of the immortalized esophageal epithelium induced by human papillomavirus / 中华实验和临床病毒学杂志

<p><b>BACKGROUND</b>Study on the promotive effects of N-nitrosopiperidine on carcinogenesis process was performed, based on the immortalization of human fetal esophageal epithelium induced by human papillomavirus (HPV) 18E6E7 genes.</p><p><b>METHODS</b>The immortalized esophageal epithelium SHEE was induced by HPV18E6E7. The cells at 17th passages were cultured in 50 ml flasks. The N-nitrosopiperidine (NPIP) 0, 2, 4, 8 mmol/L added to the cultured medium of SHEE cells for 3 weeks. The morphology, proliferation and apoptosis of the cells were studied by phase contrast microscopy and flow cytometry. Modal number of chromosomes was analyzed by standard method. Tumorigenicity of the cells was assessed by soft agar colony formation and by transplantation of cells into nude mice. Expression of HPV was detected by Western blot.</p><p><b>RESULTS</b>When cells were exposed to high concentration (8 mmol/L) of NPIP, cell death was increased, leaving a few live cells. In normal cultural medium instead of NPIP proliferative status of the cells restored after 4 weeks and the cells progressed to the proliferation stage with continuous replication and atypical hyperplasia. At the end of the 8th week, the cells appeared with large colonies in soft-agar and tumor formation in transplanted nude mice. When the cells were cultured in 2, 4 mmol/L NPIP the doubling passage was delayed and without tumor formation in transplanted nude mice. Modal number of chromosomes was 61-65, in 8 mmol/L NPIP group and control group, 56-61. Expression of HPV18 appeared in experimental and control groups.</p><p><b>CONCLUSION</b>NPIP promotes malignant change of the immortalized esophageal epithelial cells induced by HPV18E6E7. HPV18E6E7 synergy with NPIP will accelerate malignant transformation in esophageal epithelium.</p>

Expression and significance of heat shock proteins in esophageal squamous cell carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the expression and significance of HSP27, HSP60, HSP70 and HSP90 alpha in esophageal squamous cell carcinoma (ESCC) and tissues along the incision margin (TIM).</p><p><b>METHODS</b>The presence and the level of expression of HSP27, HSP60, HSP70 and HSP90 alpha were determined in 168 specimens from ESCC and 42 from tissues along TIM by EnVision immunohistochemistry and Western blotting, to compare their positive staining rates and explore the correlation between their expressions and clinicopathologic features in ESCC.</p><p><b>RESULTS</b>The positive staining rates of HSP27, HSP60, HSP70 and HSP90 alpha in ESCC and TIM were 62.0% and 42.1%, 92.7% and 63.2%, 57.9% and 22.2%, and 33.7% and 18.5%, respectively. There was very significant difference between the expression of HSP60 and HSP70 in ESCC and TIM (P < 0.01), but not significant about HSP27 and HSP90 alpha (P > 0.05). The positive staining rate of HSP27 declined with the lower grade of differentiation of ESCC (P < 0.05).</p><p><b>CONCLUSION</b>The present findings suggest that the expression of HSPs of different molecular weight in ESCC and TIM is a common event. The level of expressions of HSP60 and HSP70 are higher than those in TIM. HSP60 and HSP70 expression correlated with the biological behavior of ESCC. The expression of HSP27 was positively correlated to the grade of differentiation of ESCC. Overexpression of HSP27 may be associated to the differentiation of squamous cell carcinoma.</p>

Studies on transformation of human esophageal fibroblasts mediated by a retroviral vector containing the E6E7 ORFs of human papillomavirus type 16 / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the etiological role of human papillomavirus type 16 (HPV16) infection in the development of esophageal cancers.</p><p><b>METHODS</b>A recombinant retrovirus containing the E6E7 ORFs of HPV16 was packaged and human fetal esophageal fibroblasts were infected. The tumorigenecity of the fibroblasts was tested in SCID mice in synergy with 12-O-tetradecanoylphorbol-13-acetate (TPA).</p><p><b>RESULTS</b>Human esophageal fibroblasts infected with the recombinant retrovirus induced sarcomas in SCID mice, the existence and expression of E6E7 ORFs was confirmed in the sarcomas. Fibroblasts cultured from the sarcoma were demonstrated heteroploid by cytoflowmetry. However, tumors were not observed in human fetal esophagus infected with such virus.</p><p><b>CONCLUSIONS</b>These results revealed that the established recombinant retroviral system can successfully mediate the transference of HPV16 E6E7 genes, and such system is applicable to researches on tumorigenesis of HPV.</p>

Construction of human papilloma virus type 18 E6E7 genes in adeno-associated virus expression vector and checking its activity for malignant transformation / 中华实验和临床病毒学杂志

<p><b>BACKGROUND</b>To construct human papillomavirus type 18 (HPV18 E6E7) adeno-associated virus (AAV) for studying the role of HPV E6E7 in the development of human cancer.</p><p><b>METHODS</b>HPV18 E6E7 genes were inserted into adeno-associated virus expression vector and then infected 293 cell line. The expression of HPV18 E6E7 genes were confirmed by using RT-PCR/Southern blot assay.</p><p><b>RESULTS</b>There was HPV18 E6E7 genes in the malignantly transformed cell line. The 293TL cells compared with the parent cells transformed cells grew more rapidly, lost their contact inhibition and formed more and large colonies in soft agar.</p><p><b>CONCLUSIONS</b>HPV18 E6E7 AAV was successfully constructed and could induce malignant transformation. HPV18 E6E7 AAV can be use for studying the immortalization and malignant transformation of human normal epithelial cells.</p>

Manual microdissection of defined cells and RNA extraction for gene expression analysis of esophageal carcinoma progress / 中国医学科学院学报

<p><b>OBJECTIVES</b>To isolate cells of interest from heterogeneous tissue blocks to obtain accurate representations of molecular alterations acquired by neoplastic cells so as to meet the demands of further study on gene expression patterns of the esophageal carcinoma (EC) evolution.</p><p><b>METHODS</b>Blocks of EC were stored at -70 degrees C as close as possible to the time of surgical resection. The tissue block was embedded in OCT and frozen sections of 35 microns in thickness were cut in a cryostat under strict RNAse-free conditions. Individual frozen sections were mounted on plain glass slides and 30-gauge needle attached to a 1 ml syringe was used to microdissect defined cells in the sections. The procured cells were used for total RNA extraction.</p><p><b>RESULTS</b>An optimized protocol of manual microdissection was developed successfully whereby regions with an area as small as 1/25 mm2 could be accurately dissected. The RNA recovered from procured cells was of high quality suitable for subsequent applications of molecular analysis as assessed of 18S and 28S rRNAs by electrophoresis on agarose gel.</p><p><b>CONCLUSIONS</b>It is believed that manual microdissection is capable to procure defined cell populations from complex primary tissues, thus allowing investigation of tissue-, cell-, and function-specific gene expression patterns. The technique is simple, easy to perform, versatile, and of particular usefulness when laser capture microdissection (LCM) is practically unavailable.</p>

Intake of volatile N-nitrosamines and their ability to exogenously synthesize in the diet of inhabitants from high-risk area of esophageal cancer in southern China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Nan'ao County in Guandong Province is a high-risk area of esophageal cancer in Southern China. Of the suspected etiological factors in the environment, N-nitrosamines and their precursors have received the greatest attention.</p><p><b>METHODS</b>Sixty samples of the diet ingested by the inhabitants were collected and detected for volatile N-nitrosamines and their precursors. Five N-nitrosamines detected by Gas Chromatography-Thermal Energy Analyzer were N-nitrosodimethylamine, N-nitrosodiethylamine, N-nitrosopyrrolidine, N-nitrosopiperidine and N-nitrosomethyl-benzylamine.</p><p><b>RESULTS</b>The average content of 5 volatile N-nitrosamines in the diet was 312.0 micrograms/kg (median). The daily intake of the nitrosamines was 286.5 micrograms/head/day. Only the ability to exogenously synthesize N-nitrosopiperidine was powerful among 5 volatile N-nitrosamines. By a computerized stepwise regression analysis and curve fitting, we studied the correlation among the nitrosamines, the precursors and the major food items in the samples.</p><p><b>CONCLUSION</b>It demonstrated that a relatively high content of volatile N-nitrosamines was present in the diet collected in the area.</p>