Cytotoxic T lymphocytes elicited by dendritic cell-targeted delivery of human papillomavirus type-16 E6/E7 fusion gene exert lethal effects on CaSki cells.

Human papillomavirus (HPV) is the primary etiologic agent of cervical cancer. Consideration of safety and non human leukocyte antigen restriction, protein vaccine has become the most likely form of HPV therapeutic vaccine, although none have so far been reported as effective. Since tumor cells consistently express the two proteins E6 and E7, most therapeutic vaccines target one or both of them. In this study, we fabricated DC vaccines by transducing replication-defective recombinant adenoviruses expressing E6/E7 fusion gene of HPV-16, to investigate the lethal effects of specific cytotoxic T lymphocytes (CTL) against CaSki cells in vitro. Mouse immature dendritic cells (DC) were generated from bone marrow, and transfected with pAd-E6/E7 to prepare a DC vaccine and to induce specific CTL. The surface expression of CD40, CD68, MHC II and CD11c was assessed by flow cytometry (FCM), and the lethal effects of CTL against CaSki cells were determined by DAPI, FCM and CCK-8 methods. Immature mouse DC was successfully transfected by pAd-E6/E7 in vitro, and the transfecting efficiency was 40%-50%. A DC vaccine was successfully prepared and was used to induce specific CTL. Experimental results showed that the percentage of apoptosis and killing rate of CaSki cells were significantly increased by coculturing with the specific CTL (p <0.05). These results illustrated that a DC vaccine modified by HPV-16 E6/E7 gene can induce apoptosis of CaSki cells by inducing CTL, which may be used as a new strategy for biological treatment of cervical cancer.

Fangchinoline inhibits cell proliferation via Akt/GSK-3beta/ cyclin D1 signaling and induces apoptosis in MDA-MB-231 breast cancer cells.

Fangchinoline (Fan) inhibits cell proliferation and induces apoptosis in several cancer cell lines. The effects of Fan on cell growth and proliferation in breast cancer cells remain to be elucidated. Here, we show that Fan inhibited cell proliferation in the MDA-MB-231 breast cancer cell line through suppression of the AKT/Gsk- 3beta/cyclin D1 signaling pathway. Furthermore, Fan induced apoptosis by increasing the expression of Bax (relative to Bcl-2), active caspase 3 and cytochrome-c. Fan significantly inhibited cell proliferation of MDA- MB-231 cells in a concentration and time dependent manner as determined by MTT assay. Flow cytometry analysis demonstrated that Fan treatment of MDA-MB-231 cells resulted in cell cycle arrest at the G1 phase, which correlated with apparent downregulation of both mRNA and protein levels of both PCNA and cyclin D1. Further analysis demonstrated that Fan decreased the phosphorylation of AKT and GSK-3beta. In addition, Fan up-regulated active caspase3, cytochrome-c protein levels and the ratio of Bax/Bcl-2, accompanied by apoptosis. Taken together, these results suggest that Fan is a potential natural product for the treatment of breast cancer.

DAXX silencing suppresses mouse ovarian surface epithelial cell growth by inducing senescence and DNA damage.

Mouse ovarian surface epithelium (OSE) is a single layer of cubodial epithelial cells that covers the ovary surface and is involved in regulating the secretion and transport of 17ß-hydroxysteroid dehydrogenase. Recently, OSE cells have attracted particular interest as a major source of ovarian cancer. Death-associated protein DAXX along with PML (promyelocytic leukemia protein) nuclear bodies (PML-NBs) reportedly play roles in transcriptional regulation and apoptosis. However, little is known regarding a role for DAXX in mOSE cells. In this study, we both over-expressed DAXX and depleted DAXX in primary mOSE cells. We found that Daxx deletion accelerated senescence in a p53/p21-dependent manner and promoted DNA damage by interacting with PML bodies without affecting cell cycle progression. These results suggest that DAXX may transform mOSE cells to an ovarian oncogenic phenotype and may be an anti-cancer target.

MCPH1 Protein Expression in Normal and Neoplastic Lung Tissues.

Lung cancer is the most common cause of cancer-related death in the world. The main types are small-cell lung carcinoma (SCLC) and non-small-cell lung carcinoma (NSCLC), the latter including squamous cell carcinoma (SCC), adenocarcinoma and large cell carcinoma. NSCLCs account for about 80% of all lung cancer cases. Microcephalin (MCPH1), also called BRIT1 (BRCT-repeat inhibitor of hTERT expression), plays an important role in the maintenance of genomic stability. Recently, several studies have provided evidence that the expression of MCPH1 gene is decreased in several different types of human cancers. We evaluated the expression of protein MCPH1 in 188 lung cancer and 20 normal lung tissues by immunohistochemistry. Positive MCPH1 staining was found in all normal lung samples and only some cancerous tissues. MCPH1-positive cells were significantly lower in lung carcinoma compared with normal tissues. Furthermore, we firstly found that MCPH1 expression in lung adenocarcinoma is higher than its expression in squamous cell carcinoma. Change in MCPH1 protein expression may be associated with lung tumorigenesis and may be a useful biomarker for identification of pathological types of lung cancer.

[HPV caused pathological changes in genital system of mice].

The recombined adenovirus DNA was transfected into 293 cells for packing and amplification of replication-deficient Ad-CMV-E6/E7, Ad-K14 -E6/E7 virus was purified by CsCl density gradient centrifugation , recombined adenovirus Ad-CMV-E6/E7, Ad-K14 -E6/E7 were used as experimental group, while pAd-CMV and pAdtrack-K14 were used as control group. Four of them were injected through one main vein of nude mice tail respectively. These mice were then treated with 0.05 mg 17beta-estradiol over 12 weeks. Mice were anaesthesiaed with 2.5% Avertint and the vagina, mammary gland, ovaries and uterus were dissected and fixed in 3.75% paraformaldehyde overnight at 4 degrees C. Paraffin-embedded sections, HE staining and identification of P53 and Bcl-2 protein via immunohistochemistry were performed. The expression of E6/E7 was verified by RT-PCR in different tissue of nude mice. HE staining showed evident hyperplasy in cervix-uterus transformation zone of experimental group 2. The expression of mutant P53 and Bcl-2 were higher than control group via immunohistochemical S-P method in uterus stroma-cell. Western blotting also showed that E6 protein was expressed. The expression of E6/E7 was higher than control group by human cytokeratin promoter 14 and hyperlasy changes were detected in epithelial tissue of cervix-uterus transformation zone.

RNAi-mediated silencing of the Bmi-1 gene causes growth inhibition and enhances doxorubicin-induced apoptosis in MCF-7 cells.

The oncogene Bmi-1 is a member of the Polycomb group gene family. Its expression is found to be greatly increased in a number of malignant tumors including breast cancer. This could suggest Bmi-1 as a potent therapeutic target. In this study, RNAi was introduced to down-regulate the expression of Bmi-1 in a highly malignant breast adenocarcinoma cell line, MCF-7. A thorough study of the biological behavior and chemosensitivity changes of the MCF-7 cells was carried out in context to the therapeutic potential of Bmi-1. The results obtained indicated that siRNA targeting of Bmi-1 could lead to an efficient and specific inhibition of endogenous Bmi-1 activity. The mRNA and protein expression of Bmi-1 were determined by RT-PCR and Western blot, respectively. Furthermore, silencing of Bmi-1 resulted in a drastic inhibition of the growth of MCF-7 cells as well as G(1) /S phase transition. The number of target cells was found to increase in phase G (0) /G (1) and decrease in the S phase, but no increase in the basal level of apoptosis was noticed. On the other hand, a reduction in the expression of cyclin D1 and an increase in the expression of p21 were also noticed. Silencing of Bmi-1 made the MCF-7 cells more sensitive to the chemotherapeutic agent doxorubicin and induced a significantly higher percentage of apoptotic cells. Here, we report on a study regarding the RNAi-mediated silencing of the Bmi-1 gene in breast cancer.

RNAi-mediated silencing of the Bmi-1 gene causes growth inhibition and enhances doxorubicin-induced apoptosis in MCF-7 cells

The oncogene Bmi-1 is a member of the Polycomb group gene family. Its expression is found to be greatly increased in a number of malignant tumors including breast cancer. This could suggest Bmi-1 as a potent therapeutic target. In this study, RNAi was introduced to down-regulate the expression of Bmi-1 in a highly malignant breast adenocarcinoma cell line, MCF-7. A thorough study of the biological behavior and chemosensitivity changes of the MCF-7 cells was carried out in context to the therapeutic potential of Bmi-1. The results obtained indicated that siRNA targeting of Bmi-1 could lead to an efficient and specific inhibition of endogenous Bmi-1 activity. The mRNA and protein expression of Bmi-1 were determined by RT-PCR and Western blot, respectively. Furthermore, silencing of Bmi-1 resulted in a drastic inhibition of the growth of MCF-7 cells as well as G1/S phase transition. The number of target cells was found to increase in phase G0/G1 and decrease in the S phase, but no increase in the basal level of apoptosis was noticed. On the other hand, a reduction in the expression of cyclin D1 and an increase in the expression of p21 were also noticed. Silencing of Bmi-1 made the MCF-7 cells more sensitive to the chemotherapeutic agent doxorubicin and induced a significantly higher percentage of apoptotic cells. Here, we report on a study regarding the RNAi-mediated silencing of the Bmi-1 gene in breast cancer.

Identification and characterization of a splice variant of the catalytic domain of mouse NTE-related esterase.

Patatin-domain containing proteins constitute a large family of enzymes including known lipases that hydrolyze triglycerides, diglycerides, and phospholipids, some of which still remain to be characterized. One of those is NTE-related esterase (NRE), which exhibits sequence and domain homology to neuropathy target esterase (NTE). A splice variant of the catalytic domain of mouse NRE (mNRECV) was identified in multiple adult tissues, including brain, kidney, liver and testis. Genomic organization showed that mNRECV gene lacked the 22nd exon of mouse NRE and the 14th exon termination site of mNRECV was behind of 5 bp with the comparison of the 34th exon of mNRE gene. Over-expression of mNREC and mNRECV in mammalian cells showed that they had similar phenyl valerate esterase activities, but different from human NTE esterase domain. Subcellular distribution of an enhanced green fluorescent protein-mNRECV fusion protein was mainly observed to colocalize with endoplasmic reticulum in the juxtanuclear area and a little in cytoplasm. Moreover, autophagy/lysosome pathway was found to be involved in the degradation of mNRECV protein by inhibition and induction of autophagy, as well as co-location of mNRECV-EGFP with lysosomes. The high identity between mNRECV and mNREC suggested that mouse NRE has similar characteristics.

[Rapid construction of full-length MnSOD cDNA of chickens by one-step 3'RACE].

RACE (rapid amplification of cDNA ends) is a popular technique to rapidly obtain the full-length cDNA. After obtaining the 3' cDNA and 5' cDNA fragments with a overlapped region by 3' RACE and 5' RACE, the full-length cDNA could be generated by end-to-end PCR or subcloning. In this study, 3' RACE combined with touch-down PCR was successfully used for the rapid construction of full-length MnSOD cDNA of chickens. Compared with the conventional end-to-end PCR or subcloning, this method, called one-step 3' RACE, is fast, economical and highly specific. It especially fits the rapid construction of full-length cDNA by RACE method.