27463351
Beta7 integrins contribute to skin graft rejection.
BACKGROUND
Because integrins alpha4beta7 and alphaEbeta7 contribute to epidermotropism of T-cells during skin inflammation, we sought to study their role in skin allograft rejection.


METHODS
Wild-type (WT) (beta7+/+) and beta7 gene knockout (beta7-/-) C57BL/6 (H-2(b)) mice and SJL/J (H-2(s)) mice served as donors and recipients of allogeneic skin grafts. An anti-integrin beta7 subunit mAb (FIB504.64) was used to treat WT beta7+/+ C57BL/6 recipients of skin grafts from SJL/J mice.


RESULTS
WT C57BL/6 recipients acutely rejected skin from SJL/J mice in 13 days. In contrast, the survival of SJL/J skin on either beta7-/- gene knockout or WT C57BL/6 recipients treated with anti-beta7 subunit mAb, was prolonged by 6 to 7 additional days (P<0.01). The survival of skin allografts from either beta7-/- or beta7+/+ C57BL/6 mice received by SJL/J recipients was not prolonged (P >0.05).


CONCLUSIONS
Beta7 integrins contribute to skin graft rejection, in accord with their role in mediating the epidermotropism of T-cells during skin inflammation.
1623657
Regression of solid tumors by engineered overexpression of von Hippel–Lindau tumor suppressor protein and antisense hypoxia-inducible factor-1α
The von Hippel–Lindau tumor suppressor protein (pVHL) suppresses tumor formation by binding the α subunits of hypoxia-inducible factors (HIFs) responsible for stimulating tumor angiogenesis and glycolysis, targeting them for ubiquitination and proteasomal destruction. Loss of pVHL leads to the development of sporadic renal cell carcinomas (RCCs). In the present study, we sought to determine whether engineered overexpression of pVHL in tumors other than RCC can inhibit tumor growth, either as a monotherapy, or in combination with antisense HIF-1α therapy. Intratumoral injection of subcutaneous EL-4 thymic lymphomas with an expression plasmid encoding pVHL resulted in the downregulation of HIF-1α and vascular endothelial growth factor (VEGF). There was a concomitant reduction in tumor angiogenesis and increased tumor cell apoptosis due in part to downregulation of Bcl-2 expression. VHL therapy resulted in the complete regression of small (0.1 cm diameter) tumors whereas, in contrast, large (0.4 cm diameter) EL-4 tumors were only slowed in their growth. Nevertheless, large tumors completely regressed in response to intratumoral injection of a combination of antisense HIF-1α and VHL plasmids. Combination therapy resulted in increased losses of HIF-1α, VEGF, and tumor blood vessels, and increased tumor cell apoptosis. These novel results suggest that synergistic therapies that simultaneously block the expression or function of HIF-1α, and enhance the expression or function of VHL may be beneficial in the treatment of cancer.
5630256
Overexpression of von Hippel-Lindau tumor suppressor protein and antisense HIF-1α eradicates gliomas
The von Hippel–Lindau tumor suppressor protein (pVHL) suppresses tumor formation by binding the α subunits of hypoxia-inducible-factors responsible for stimulating tumor angiogenesis and glycolysis, and targeting them for ubiquitination and proteasomal destruction. Loss of pVHL leads to tumorigenesis and development of sporadic renal cell carcinomas and central nervous system hemangioblastomas. In the present study, we investigated whether engineered overexpression of pVHL in C6 glioma cells, which already express endogenous pVHL, would suppress the tumorigenicity of this particular tumor cell type. C6 cells overexpressing VHL displayed a reduced growth rate (70% inhibition) compared to the parental cell line when subcutaneously implanted in athymic (nu/nu) mice. Growth inhibition was associated with a 50% reduction in the number of tumor vessels and a 60% increase in tumor cell apoptosis, due in part to downregulation of HIF-1, VEGF, and the antiapoptotic factor Bcl-2, respectively. Gene transfer of VHL suppressed the growth of established C6 gliomas, and synergized with antisense HIF-1 to completely eradicate tumors. The data suggest that VHL gene therapy and/or agents that increase VHL expression could have utility in the treatment of gliomas, particularly when combined with agents that inhibit the expression or function of HIF-1.
9295570
Antisense HIF-1α prevents acquired tumor resistance to angiostatin gene therapy
Angiostatin is a naturally occurring inhibitor of angiogenesis that is being developed as a drug to fight cancer. In this study we reveal that EL-4 tumors established in mice rapidly develop resistance to angiostatin gene therapy by upregulating hypoxia-inducible pathways. Angiostatin initially delayed tumor growth for 6 days by reducing blood vessel density. However, tumors quickly responded by upregulating the production of hypoxia-inducible factor-1α (HIF-1α) and its effector vascular endothelial growth factor (VEGF) in response to increasing tumor hypoxia, leading to restored angiogenesis and rapid tumor growth. Theoretically, blockade of HIF-1 should prevent resistance to anti-angiogenic therapy by preventing a tumor from responding to induced hypoxia. Antisense HIF-1α inhibited the expression of HIF-1α and of the HIF-1 effectors VEGF, glucose transporter-1 and lactate dehydrogenase. As a monotherapy, it was effective in eradicating small 0.1 cm diameter tumors, but only delayed the growth of large 0.4 cm diameter tumors. In contrast, timed injection of a combination of angiostatin and antisense HIF-1α plasmids completely eradicated large EL-4 tumors within 2 weeks, and prevented upregulation of hypoxia-inducible pathways induced by angiostatin. The data indicate that blocking hypoxia-inducible pathways by antisense HIF-1α can circumvent hypoxia-induced drug resistance and thereby augment the efficacy of anti-angiogenic therapies.
19099233
Intramuscular delivery of antiangiogenic genes suppresses secondary metastases after removal of primary tumors
The success of surgery to remove primary tumors can be compromised by the subsequent outgrowth of metastases. It is recognized that primary tumors secrete antiangiogenic factors that suppress the outgrowth of their daughter metastases. In accord we show here that surgical removal of primary EL-4 lymphomas led to a marked decrease in the levels of circulating angiostatin and endostatin, and promoted the growth of distant nodular tumors. Expression vectors encoding angiostatin and endostatin, formulated with poly-N-vinyl pyrrolidone (PVP), were injected into the tibialis and gastrocnemia muscles, leading to expression of angiostatin and endostatin in muscle fibers. High levels of biologically active exogenous proteins were secreted into the circulation. Intramuscular gene therapy with angiostatin and endostatin plasmids significantly inhibited tumor vascularity and induced tumor cell apoptosis, and thereby suppressed the growth of secondary subcutaneous and disseminated metastatic tumors in the lung and liver. Simultaneous intramuscular delivery of both angiostatin and endostatin plasmids significantly prolonged the survival of mice after removal of primary tumors. These results suggest that intramuscular gene transfer of angiostatin and endostatin might serve as a prophylactic cancer-prevention strategy to combat the recurrence of cancer after surgical resection of primary tumors.
29659432
Up-regulation of survivin by AKT and hypoxia-inducible factor 1α contributes to cisplatin resistance in gastric cancer.
This study investigated the contribution of survivin and its upstream regulators, AKT and hypoxia-inducible factor 1α (HIF-1α), to the resistance of gastric cancer cells to cisplatin (CDDP). We found that over-expression of survivin increased the resistance of SGC7901 and BGC823 gastric cancer cells to CDDP. Its over-expression abrogated CDDP-induced inhibition of cell proliferation and CDDP-induced cell apoptosis. In contrast, down-regulation of survivin expression using small hairpin RNA (shRNA) vectors and the small-molecule inhibitor YM155, or inhibition of survivin function using a recombinant cell-permeable dominant-negative survivin protein (dNSur9), promoted CDDP-induced apoptosis. CDDP-resistant sub-lines generated from the parental SGC7901 and BGC823 cells by exposure to increasing concentrations of CDDP expressed higher levels of HIF-1α and survivin in response to hypoxia, and higher levels of phosphorylated AKT (pAKT). Specific inhibition of AKT reduced the expression of HIF-1α and survivin, whereas specific inhibition or depletion of HIF-1α reduced survivin expression but had no effect on the expression of phosphorylated AKT. The expression levels of survivin affected the therapeutic efficacy of CDDP in treating gastric tumors in mice. Specific inhibition of survivin, AKT and HIF-1α enhanced the sensitivity of CDDP-resistant cells to CDDP. Specific inhibition of survivin, AKT and HIF-1α synergized with CDDP to suppress the growth of gastric tumors that had been engineered to overexpress survivin. In summary, the results provide evidence that up-regulation of survivin by AKT and HIF-1α contributes to CDDP resistance, indicating that inhibition of these pathways may be a potential strategy for overcoming CDDP resistance in the treatment of gastric cancer.
23980348
Genetic Loss of Faah Compromises Male Fertility in Mice1
Abstract Marijuana is the most commonly used illicit drug. Although there is some indication that reproductive functions in males are impaired in chronic marijuana users, the genetic evidence and underlying causes remain largely unknown. Herein we show that genetic loss of Faah, which encodes fatty acid amide hydrolase (FAAH), results in elevated levels of anandamide, an endocannabinoid, in the male reproductive system, leading to compromised fertilizing capacity of sperm. This defect is rescued by superimposing deletion of cannabinoid receptor 1 (Cnr1). Retention of Faah−/− sperm on the egg zona pellucida provides evidence that the capacity of sperm to penetrate the zona barrier is hampered by elevated anandamide levels. Collectively, the results show that aberrant endocannabinoid signaling via CNR1 impairs normal sperm function. Besides unveiling a new regulatory mechanism of sperm function, this study has clinical significance in male fertility.
241983
Interruption of nuclear localization of ATBF1 during the histopathologic progression of head and neck squamous cell carcinoma.
BACKGROUND
The AT-motif binding factor 1 (ATBF1) gene is frequently altered at the genetic level in several types of cancer, but its protein expression and subcellular localization have not been well studied in human cancers, including head and neck squamous cell carcinomas (HNSCCs).


METHODS
ATBF1 expression and localization were examined in 5 cell lines and 197 clinical specimens of HNSCC, and correlated with pathologic and clinical characteristics.


RESULTS
ATBF1 was predominantly localized in the nucleus of hyperplastic squamous epithelium. Whereas nuclear ATBF1 dramatically decreased in invasive tumors (p = .0012), cytoplasmic ATBF1 levels progressively increased from dysplasia to invasive tumors (p < .0001), and the increase correlated with poor survival. Reduced nuclear ATBF1 level was also detected in HNSCC cell lines.


CONCLUSIONS
Nuclear localization of ATBF1 is frequently interrupted in HNSCC, and the interruption is significantly associated with the progression of HNSCC. The cytoplasmic ATBF1 level could be useful for predicting patient survival.
8373412
Expression of uncoupling protein 3 is upregulated in skeletal muscle during sepsis.
Uncoupling protein 3 (UCP3) is a member of the mitochondrial transporter superfamily that is expressed primarily in skeletal muscle. UCP3 is upregulated in various conditions characterized by skeletal muscle atrophy, including hyperthyroidism, fasting, denervation, diabetes, cancer, lipopolysaccharide (LPS), and treatment with glucocorticoids (GCs). The influence of sepsis, another condition characterized by muscle cachexia, on UCP3 expression and activity is not known. We examined UCP3 gene and protein expression in skeletal muscles from rats after cecal ligation and puncture and from sham-operated control rats. Sepsis resulted in a two- to threefold increase in both mRNA and protein levels of UCP3 in skeletal muscle. Treatment of rats with the glucocorticoid receptor antagonist RU-38486 prevented the sepsis-induced increase in gene and protein expression of UCP3. The UCP3 mRNA and protein levels were increased 2.4- to 3.6-fold when incubated muscles from normal rats were treated with dexamethasone (DEX) and/or free fatty acids (FFA) ex vivo. In addition, UCP3 mRNA and protein levels were significantly increased in normal rat muscles in vivo with treatment of either DEX or FFA. The results suggest that sepsis upregulates the gene and protein expression of UCP3 in skeletal muscle, which may at least in part be mediated by GCs and FFA.
22500408
Health payment-induced poverty under China's New Cooperative Medical Scheme in rural Shandong.
OBJECTIVE
To measure the incidence and severity of health payment-induced poverty of rural households under the New Cooperative Medical Scheme (NCMS) in rural Shandong, China.


METHOD
We collected primary data from a household survey to identify catastrophic health payments and measure associated health payment-induced poverty in a county of Shandong province. From a stratified random cluster sample of 3101 households, 375 households that might be at risk of catastrophic payments were identified and interviewed. A validity test of the screening method was conducted, from which we obtained the adjusted total number of households with catastrophic payments in the sample of 3101. The health payment-induced poverty incidence and severity were compared without and with NCMS reimbursements.


RESULTS
Before the NCMS intervention, 5.06% of the sample households fell below the national poverty line due to health payments in 2004, compared with 4.03% after reimbursements. With NCMS reimbursements, the health payment-induced poverty gap of those households still remaining below the Chinese national poverty line dropped by 19.2% to an average of 977.2 Yuan.


CONCLUSION
Out-of-pocket health payments remain a severe burden for rural households. Financial protection from the NCMS was limited.
575273
Surface-emitting circular DFB, disk- and ring- Bragg resonator lasers with chirped gratings: a unified theory and comparative study.
We have developed a theory that unifies the analysis of the modal properties of surface-emitting chirped circular grating lasers. This theory is based on solving the resonance conditions which involve two types of reflectivities of chirped circular gratings. This approach is shown to be in agreement with previous derivations which use the characteristic equations. Utilizing this unified analysis, we obtain the modal properties of circular DFB, disk-, and ring- Bragg resonator lasers. We also compare the threshold gain, single mode range, quality factor, emission efficiency, and modal area of these types of circular grating lasers. It is demonstrated that, under similar conditions, disk Bragg resonator lasers have the highest quality factor, the highest emission efficiency, and the smallest modal area, indicating their suitability in low-threshold, high-efficiency, ultracompact laser design, while ring Bragg resonator lasers have a large single mode range, high emission efficiency, and large modal area, indicating their suitability for high-efficiency, large-area, high-power applications.