High-titer replication-defective recombinant adenovirus expressing HSV-TK gene was constructed. Firstly, shuttle plasmid pAdCMVTK containing HSV-TK gene and CMV promoter was constructed and then recombined with right arm of adenovirus DNA. Secondly, the positive plaques containing recombinant adenovirus were identified and selected out by PCR and Southern blotting after infection into human embryo kidney 293 cells. The titer of recombinant adenovirus AdCMVTK was determined by plaque forming assay and it was as high as 10(12) pfu/ml. Tumor cells were infected with AdCMVTK and then treated with GCV. Cytotoxic effects were assayed with MTT method. HeLa, A549 and LoVo cells infected with AdCMVTK (M. O. I. = 100) became sensitive to the prodrug GCV, with IC50 less than 4 mumol/L. Significant bystander effect was observed. Results here show that the AdCMVTK/GCV system might be potential in the gene therapy for cancer.
This study investigated the relationship between genetic polymorphism in the MDR1 (C3435T, G2677T) and the development of steroid-induced osteonecrosis of femoral head (ONF) in Chinese systemic lupus erythematosus (SLE) patients. 127 patients with active SLE, receiving 40 mg/day or more prednisolone were included. Patients were observed for the development of ONF by magnetic resonance imaging (MRI) and plain radiography first at three months after the beginning of steroid treatment and subsequently every year for five years. Genomic DNA was obtained from peripheral blood lymphocytes. The MDR1 2677G > T and 3435C > T genotypes were determined by the PCR-RFLP assay. 21 patients developed steroid-induced ONF. The incidence of ONF was significantly higher in steroid pulse therapy. The MDR1 3435 TT genotypes were significantly lower in the incidence of ONF (adjusted odds ratio = 0.14, 95% CI 0.017-1.153, p = 0.038). The MDR1 2677 TT was also lower in the incidence of ONF (adjusted odds ratio = 0.21, 95% CI 0.018-1.301, p = 0.05). Our findings suggest that MDR1 (ABCB1) gene polymorphisms can be used for predicting the development of ONF.
Although epidural analgesia may provide adequate pain relief and minimize systemic side effects, long-term, even permanent placement of epidural catheter for chronic or cancer-related pain management carries a potential risk of both superficial and deep infection. The development of antibiotics microspheres that could be dwelled in epidural drug-delivery devices is likely to achieve a significant advance allowing antibiotics given by the intradiscal route to control catheter-related infections. In the present study, the composite microspheres composed of double-walled microcapsules and PLGA were constructed for encapsulating water-soluble antibiotics, cefazolin. The results show that these microspheres could efficiently control the initial release of drug, which was only 3.0% at 2 h. Cefazolin encapsulated in the composite microspheres released gradually nearly in a constant rate in the first 16 days, and still maintained a relative fast rate in the next 14 days, indicating that composite microspheres could improve the incomplete release of entrapped drugs.
The liquid nitrogen cryotherapy was used to treat conjunctival malignant melanoma. Light and transmission electron microscopic examinations were carried out before, during and after the treatment. It was discovered that the tumor cells died within a few minutes after the cryoapplication. Under transmission electron microscope, marked necrosis of tumor cells was seen 10-14 days after the treatment and a large amount of collagenous fibers and fibroblast hyperplasia were seen in the tumor in 3-4 weeks following the application, while the tumor cells were seldom found. Under light microscope, as significant necrosis of the malignant melanoma occurred, the surface conjunctival epithelium gradually grew and covered the defect of the conjunctiva, showing that the malignant melanoma cells are much more sensitive to the cryoapplication than the normal conjunctival epithelial cells.
Peroxisome proliferator-activated receptor γ (PPARγ) regulates fatty acid storage and glucose metabolism. Recently, PPARγ has been reported to be involved in cancer. The present study reported a PPARγ consensus binding site (AGGTCA) in the ptprf promoter and identified a strong association between PPARγ and PTPRF expression, as well as their tumor suppressor roles in a v-Ha-Ras-induced model of breast cancer.The prognostic potential of PPARγ was assessed with a KM analysis of raw data from 3,951 breast cancer patients. The expression of PPARγ and PTPRF in the rat breast cancer cell lines was detected by Western blot and qPCR. The impact of PPARγ on cancer cell migration, invasion, and growth was confirmed using cell migration assay, transwell cell invasion assay, tri-dimensional soft agar culture, respectively. The binding of PPARγ with the ptprf promoter was then examined using electrophoretic mobility shift assay. The inhibitory effect of PPARγ on tumor growth was then examined in mouse tumor model in vivo.It was identified that PPARγ expression is lost in the aggressive v-Ha-Ras-induced breast cancer cell line FE1.2 but highly expressed in less malignant FE1.3 cells. Exogenous expression of PPARγ in FE1.2 cells (FE1.2-PPARγhi) resulted in a marked inhibition of proliferation compared with that in FE1.2-Vector control group. FE1.2-PPARγhi cells also exhibited reduced migration, invasion, and colony formation abilities compared with those of the controls. The PPARγ agonist rosiglitazone also suppressed the malignant properties of FE1.2 cells. Protein tyrosine phosphatase receptor F (PTPRF), a downstream target of PPARγ, was markedly induced in FE1.2-PPARγhi cells. A PPARγ consensus binding site (AGGTCA) was identified in the ptprf promoter, and an electrophoretic mobility shift assay confirmed that PPARγ bind to this promoter. Similar to the effect of vector-mediated overexpression of PPARγ, ectopic overexpression of PTPRF in FE1.2 cells led to reduced proliferation. Furthermore, a PPARγ antagonist (GW9662) and PTP inhibitor (NSC87877) abrogated the suppressive function of PPARγ and PTPRF in FE1.2 cells, respectively. PPARγ overexpression or activation suppressed the progression and distant organ metastasis of breast cancer cells in a NOD/SCID mouse model.These results suggest that PPARγ inhibits tumor cell proliferation, at least in part, through direct regulation of the ptprf gene and that PPARγ is a potential target for breast cancer treatment.
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