RNF8 promotes epithelial-mesenchymal transition of breast cancer cells.

BACKGROUND: Epithelial-mesenchymal transition (EMT) is a crucial step for solid tumor progression and plays an important role in cancer invasion and metastasis. RNF8 is an ubiquitin E3 ligase with RING domain, and plays essential roles in DNA damage response and cell cycle regulation. However the role of RNF8 in the pathogenesis of breast cancer is still unclear. METHODS: The expression of RNF8 was examined in different types of breast cell lines by Western Blotting. EMT associated markers were examined by Immunofluorescence and Western Blotting in MCF-7 when RNF8 was ectopically overexpressed, or in MDA-MB-231 when RNF8 was depleted. Transwell and wound healing assays were performed to assess the effect of RNF8 on cell mobility. The xenograft model was done with nude mice to investigate the role of RNF8 in tumor metastasis in vivo. Breast tissue arrays were used to examine the expression of RNF8 by immunohistochemistry. Kaplan-Meier survival analysis for the relationship between survival time and RNF8 signature in breast cancer was done with an online tool ( http://kmplot.com/analysis/ ). RESULTS: RNF8 is overexpressed in highly metastatic breast cancer cell lines. Overexpression of RNF8 in MCF-7 significantly promoted EMT phenotypes and facilitated cell migration. On the contrary, silencing of RNF8 in MDA-MB-231 induced MET phenotypes and inhibited cell migration. Furthermore, we proved that these metastatic behavior promoting effects of RNF8 in breast cancer was associated with the inactivation of GSK-3ß and activation of ß-catenin signaling. With nude mice xenograft model, we found that shRNA mediated-downregulation of RNF8 reduced tumor metastasis in vivo. In addition, we found that RNF8 expression was higher in malignant breast cancer than that of the paired normal breast tissues, and was positively correlated with lymph node metastases and poor survival time. CONCLUSIONS: RNF8 induces EMT in the breast cancer cells and promotes breast cancer metastasis, suggesting that RNF8 could be used as a potential therapeutic target for the prevention and treatment of breast cancer.

Expression of argininosuccinate synthetase in patients with hepatocellular carcinoma.

BACKGROUND AND AIM: Arginine is a nonessential amino acid for humans and mice because it can be synthesized from citrulline by argininosuccinate synthetase (ASS) and argininosuccinate lyase. Hepatocellular carcinoma (HCC) is believed to be auxotrophic for arginine through the lack of expression of ASS. However, there are also some ASS-positive HCC cells. Therefore, the aim of this article was to study the levels of arginine and the expression of ASS in patients with HCC. METHODS: Thirty patients with HCC who had undergone HCC surgery were enrolled in the study. Serum arginine levels were determined with an automatic amino acid analyzer. ASS expression was examined by Western blot and immunohistochemistry. Methylation specific polymerase chain reaction and methylation sequencing were performed to detect the methylation of DNA encoding ASS. RESULTS: There was a decrease of arginine in HCC patients compared with that of healthy control. High expression of ASS was found in the adjacent tissues by Western blot and immunohistochemistry. Little ASS expression was found in most HCC tissues, but there were also some HCC tissues that expressed low levels of ASS. Methylation of the DNA encoding ASS was obviously higher in HCC tissues than that in paired adjacent tissues. CONCLUSIONS: ASS expression is decreased significantly in HCC tissues. The downregulation of arginine and ASS expression may be a self-defense action of the body against malignant tumors, and the decreased arginine and ASS levels in HCC patients are an advantage for the arginine deiminase treatment.

A new cytotoxic flavonoid from the fruit of Sinopodophyllum hexandrum.

Constituents of the fruit of Sinopodophyllum hexandrum (Royle) Ying (Sinopodophylli Fructus) were investigated. A new flavonoid, 8,2'-diprenylquercetin 3-methyl ether along with 9 known compounds were isolated and identified. Among them, the new compound 8,2'-diprenylquercetin 3-methyl ether exhibited cytotoxic activities against MDA-231 and T47D breast cancer cell lines, quercetin, kaempferol and rutin were isolated from Sinopodophylli Fructus for the first time.

[Immune regulating activity of a novel organoselenium compound ethaselen-1 in C57/BL mice].

OBJECTIVE: To detect the Immune regulating activity of ethaselen-1 (Eb1), a novel organoselenium compound, in C57/BL mice transplanted with Lewis lung cancer(LLC). METHODS: The LLC transplanted C57/BL mice models were established, and the mice was randomly divided into four groups, including high dose Eb1 group (25.0 mg/kg),low dose Eb1 group (12.5 mg/kg), positive control group (levamisole, LMS, 2.0 mg/kg) and negative control group(solvent). Intraperitoneal injections (ip.) of the four pharmaceuticals were performed once a day through the abdominal wall separately, from the second to the eighth day after cancer was transplanted. On the eleventh day, six mice of each group were killed and relative weight of spleen, transforming activity of spleen lymphocytes, NK cell activity, LAK cell activity and percentage of CD4(+)CD8(+)T lymphocyte were detect. RESULTS: Compared with the control group, high dose Eb1 could obviously increase the relative weight of spleen (150.59% and 122.55%), transforming activity of spleen lymphocytes(162.25% and 561.98%), NK cell activity(78.60% and 219.42%) and percentage of CD4(-)/CD8(+) T lymphocyte(104.72% and 105.87%) in normal mice and LLC mice. Compared with the control group, high dose Eb1 could also increase LAK cell activity of LLC mice by 195.11%. CONCLUSION: The novel organoselenium compound Eb1 has immune regulating activity in vivo.

Stereoselective synthesis of jaspine B from D-xylose.

The natural cytotoxic marine compound, jaspine B, is stereoselectively synthesized from D-xylose in 11 linear steps with a 23.9% overall yield. The key step in the synthesis involves an iodine-induced debenzylation of a primary alcohol and the subsequent 2,5-cyclization to fit the required configuration of jaspine B. A preliminary bioassay shows strong inhibition activities against human MDA231, Hela, and CNE cell lines, indicating potential usage in various cancer treatments.

[The antitumor activity of Shuang-Xi-Zuo-Wan-1 in C57/BL mice].

OBJECTIVE: To detect the antitumor activity of Shuang-Xi-Zuo-Wan-1(Eb), a novel organoselenium compound, in C57/BL mice transplanted with Lewis lung cancer(LLC). METHODS: The LLC transplanted C57/BL mice model was established,and the mice were randomly divided into four groups, including high dose Eb group (25.0 mg/kg), low dose Eb group (12.5 mg/kg), positive control group (DDP, 2.0 mg/kg) and negative control group (solvent). Each group had twelve mice. Intraperitoneal injections (ip.) of four pharmaceuticals were performed once a day through the abdominal wall separately, from the second to the eighth days after cancer was transplanted. On the eleventh day, six mice of each group were killed and the influences of Eb on growth speed, size, weight, invasion, inhibitory rate, proliferation index and apoptosis rate of LLC were observed and calculated. The remaining mice were fed till all of them died naturally and the average survival time of each group was calculated. RESULTS: Eb could inhibit the growth and infiltration of LLC (the cancer inhibitory rate of high does Eb was 80.31%) obviously and prolong the average survival time of these with mice cancer. After being given Eb, the nuclear of the cancer cell concentrated and the fission phase cells reduced. In addition,the number of apoptosis cancer cells increased. CONCLUSION: The novel organoselenium compound Eb has antitumor activity in vivo. It can inhibit the growth and infiltration of LLC in mice, and induce the apoptosis of cancer cells.

[Culture of osteoblasts by serial explant culture and comparison of their characteristics].

OBJECTIVE: To Investigate a simple, economical and efficient method of primary osteoblast culture and compare their characteristics. METHODS: Primary osteoblasts of 1 st-4 th series explant culture from calvarial bones of neonatal Sprague-Dawley rats, were collected and osteoblasts shape, mitosis, proliferation, ALP activity and immunohistological expression of osteocalcin and BMP-2 observed. RESULTS: No difference was found in cell shape, spread, confluence, ALP activity as well as immunohistological stain of osteocalcin and BMP-2 of the osteoblasts, which had been harvested from the 1 st-4 th series explant cultures of Sprague-Dawley rats. CONCLUSION: Series explant culture can harvest the same kind of osteoblasts as the explant culture, and more osteoblasts can be obtained at a single time. It saves money and time and is easy to manipulate.

Effects of cerulenin on the endogenous fatty acid synthetic activity in squamous cell carcinoma of the oral cavity.

PURPOSES: Inhibition of cerulenin on the endogenous fatty acid synthetic activities of oral squamous cell carcinoma (OSCC) and normal oral mucosa was assayed. METHODS: Squamous cell carcinoma and normal oral mucosa were collected fresh from surgical specimens. The collected tissues were minced in RPMI 1640 and divided into 3 groups: cerulenin treated, dimethylsulfoxide treated, and control. The tissues were incubated in [1(2)-(14)C]acetic acid, sodium salt for the last 2.5 hours of the treatment at 37 degrees C in 5% CO(2). After labeling, total lipids were extracted and counted for (14)C by scintillation counting. RESULTS: Endogenous fatty acid synthetic activities of oral squamous cell caranoma in the cerulenin-treated group decreased by 19% at 1 hour, 64% at 2 hours, and 87% at 4 hours; remained nearly unchanged in the dimethylsulfoxide-treated group; and increased slightly in the control group. The oral mucosa tissues were only mildly affected by cerulenin in fatty acid synthesis. CONCLUSIONS: Cerulenin significantly inhibits fatty acid synthetic activity in squamous cell carcinoma and only mildly affected the oral mucosa, indicating that the fatty acid synthetic pathway may be exploited as a target for developing anticancer drugs.

[Effect of wolfberry fruit and epimedium on DNA synthesis of the aging-youth 2BS fusion cells].

OBJECTIVE: To study the effect of water extracts of Wolfberry fruit (WB) and Epimedium (EM) on DNA synthesis of the aging-youth 2BS fusion cells. METHODS: Human embryonic lung diploid fibroblasts 2BS national standard strain, were used as an aging model. Cell denucleation and cell fusion techniques were applied to observe the effect of WB and EM on DNA synthesis of 2BS fusion cells. RESULTS: In the 0.025 (V/V) WB or EM water extract containing media, 2BS cells could be continuously cultured for 61.0 +/- 2.9 passages and 56.0 +/- 2.6 passages respectively, while in the control group it was only 49.0 +/- 2.6 passages (P < 0.01). After treatment with WB and EM separately for 2 hrs, the aging 2BS cells were denucleated and fused with young 2BS cells. The [3H]TdR incorporation percentage in these treated cells was significantly higher than that in the untreated control cells (P < 0.01). CONCLUSION: Both WB and EM can accelerate the DNA synthesis rate of the aging youth 2BS fusion cells and prolong the life span of 2BS cells.