Influence of deleted in colorectal carcinoma gene on proliferation of ovarian cancer cell line SKOV-3 in vivo and in vitro.

OBJECTIVE: To elucidate the effects of the deleted in colorectal carcinoma (DCC) gene on proliferation of ovarian cancer cell line SKOV-3. METHOD: An exogenous recombinant eukaryotic expression vector pcDNA3.1(+)-DCC, containing human DCC cDNA coding sequences, was constructed and transfected into SKOV-3 cells (SKOV-3/DCC). The pcDNA3.1 (+) transfected cells (SKOV-3/Neo) and SKOV-3 cells were used as the positive and negative controls, respectively. Expressions of DCC mRNA and protein were analyzed by RT-PCR and immunocytochemical analysis, respectively. Cell growth was detected by soft agar colony formation assay and MTT assay. Flow cytometry and transmission electron microscopy were used to assess the effects of DCC on cell cycle distribution and ultrastructure, respectively. BALB/c mice were used to evaluate the effects of DCC on tumorigenicity in vivo. RESULTS: RT-PCR and immunocytochemical analysis revealed the exogenous DCC gene was successfully transfected into SKOV-3 cell lines and obtained permanent expression. The half maximal inhibitory concentration (IC50) of SKOV-3/DCC cells was significantly lower than that of SKOV-3 or SKOV-3/Neo cells (all P<0.05). DCC expression caused SKOV-3 cells to be arrested in G1 phase (78.0%), and electron microscopic analysis showed SKOV-3/DCC cells displayed typical morphological changes of apoptosis. Two mice xenografted with SKOV-3/DCC cells showed no tumor tumorigenecity. The tumor volume of BALB/c mice bearing SKOV-3/DCC cells (3.403 mm(3)) was smaller than that of SKOV-3 cells (9.206 mm(3)). CONCLUSION: DCC gene may play an important role in suppressing the growth of SKOV-3 cell line and inducing apoptosis.

Changes of QT Dispersion in Hemodialysis Patients after Administrating Zhigancao Decoction ().

OBJECTIVE: To observe the alteration of QT dispersion (QTd) and QTc dispersion (QTcd) in hemodialysis patients after oral administration of Zhigancao Decoction (, Roasted Licorice Decoction, RLD). METHODS: To investigate the alteration of QTd and QTcd in 68 routine hemodialysis patients before and after hemodialysis with 12-lead electrocardiogram (ECG) after orally administrated RLD for 4 weeks. Blood was also taken for measurement of plasma electrolytes, liver function, renal function, hemoglobin (Hgb) and hematocrit (HCT). RESULTS: After hemodialysis, QTd and QTcd were prolonged evidently; the difference was significant between before and after hemodialysis (P<0.05). After RLD orally administrated for 4 weeks, QTd and QTcd only slightly increased after dialysis compared with pre-dialysis (P>0.05). The QTd and QTcd of the post-therapy-post-dialysis decreased significantly compared with the pre-therapy-post-dialysis (P<0.05). There were no other significant changes in other variables (post-therapy-pre-dialysis vs. pre-therapy-pre-dialysis, or post-therapy-post-dialysis vs. pre-therapy-post-dialysis;P>0.05). After therapy, the number of patients with supraventricular arrhythmia, occasional ventricular premature beat and multiple ventricular premature beat were decreased from 15 to 4, 10 to 2 and 7 to 1, respectively. CONCLUSION: RLD therapy not only lowered the increased QTd and QTcd after hemodialysis, but also displayed a safety profile.

Adaptive medical image encryption algorithm based on multiple chaotic mapping.

Digital images are now widely used in modern clinic diagnosis. The diagnostic images with confidential information related to patients' privacy are stored and transmitted via public networks. Secured schemes to guarantee confidentiality of patients' privacy are becoming more and more vital. This paper proposes an adaptive medical image encryption algorithm based on improved chaotic mapping in order to overcome the defects of the existing chaotic image encryption algorithm. First, the algorithm used Logistic-sine chaos mapping to scramble the plain image. Then, the scrambled image was divided into 2-by-2 sub blocks. By using the hyper-chaotic system, the sub blocks were adaptively encrypted until all the sub block encryption was completed. By analyzing the key space, the information entropy, the correlation coefficient and the plaintext sensitivity of the algorithm, experimental results show that the proposed algorithm overcomes the shortcoming of lack of diffusion in single direction encryption. It could effectively resist all kinds of attacks and has better security and robustness.

[Growth inhibitory effects of lipofectamine-mediated DCC gene on ovarian epithelial carcinoma].

OBJECTIVE: To study the inhibitory effects of lipofectamine-mediated deleted colorectal carcinoma gene on ovarian epithelial carcinoma (ovarian cancer) cell line SKOV3. METHODS: We constructed a recombinant eukaryotic expression vector pcDNA3.1 (+)-DCC containing exogenous human DCC cDNA and vector with neomycin resistance gene, which were introduced by lipofectamine-mediated gene transfection into SKOV3 cell line that does not express DCC endogenously, thus forming SKOV3/DCC. Therefore, the experimental cells were classified into SKOV3/DCC, SKOV3/Neo and SKOV3. By using reverse transcriptase-polymerase chain reaction and immunocytochemistry, the expression of DCC mRNA and its protein were examined. RESULTS: Exogenous DCC had successfully been transferred into SKOV3 cells and obtained permanent expression. The growth speed of SKOV3/DCC was slower than the other two groups, there was significant difference between them (P < 0.01). SKOV3/DCC clones number was 38 +/- 8, while SKOV3 and SKOV3/Neo were 192 +/- 8 and 186 +/- 10, respectively, there was significant difference between them (P < 0.01). The percentage of G(1) phase cells increased to 78.0%, which that of S phase decreased to 5.3% by analyzing cell cycle, there was significant difference between them (20.0% and 3.2%, P < 0.01). The ultrastructural changes of the cells were observed under electron microscope, revealing growth retardation. CONCLUSION: DCC gene played an important role in generation and development of ovarian carcinomas.

Dihydroartemisinin induces apoptosis of cervical cancer cells via upregulation of RKIP and downregulation of bcl-2.

Treatment of recurrent and metastatic cervical cancer remains a challenge, especially in developing countries, which lack efficient screening programs. In recent years, artemisinin and its derivatives, such as dihydroartemisinin (DHA), which were traditionally used as anti-malarial agent, have been shown to inhibit tumor growth with low toxicity to normal cells. In this study, we investigated mechanisms underlying the anti-tumor effect of DHA in cervical cancer. We evaluated the role of DHA on the expression of bcl-2 and Raf kinase inhibitor protein (RKIP), which is a suppressor of metastasis. The MTT assay was used to compare the proliferation of untreated and DHA-treated Hela and Caski cervical cancer cells. Flow cytometry was used to determine the percentage of cells at each stage of the cell cycle in untreated and DHA-treated cells. We used RT-PCR and western blots to determine the expression of bcl-2 and RKIP mRNA and proteins. We evaluated the effect of DHA treatment in nude mice bearing Hela or Caski tumors. DHA-treated cells showed a time- and dose-dependent inhibition of proliferation and a significant increase in apoptosis. The expression of RKIP was significantly upregulated and the expression of bcl-2 was significantly downregulated in DHA-treated cells compared with control cells. DHA treatment caused (1) a significant inhibition of tumor growth and (2) a significant increase in the apoptotic index in nude mice bearing Hela or Caski tumors. Our data suggest that DHA inhibits cervical cancer growth via upregulation of RKIP and downregulation of bcl-2.