Tumor-derived macrophage migration inhibitory factor promotes an autocrine loop that enhances renal cell carcinoma

The macrophage migration inhibitory factor (MIF) is a hypoxia regulated gene that has a variety of tumorigenic functions. In clear cell renal carcinoma (CCRC), hypoxic signaling is constitutively active because of the frequent loss of function of the von Hippel-Lindau tumor suppressor protein. We therefore sought to assess the expression of MIF in CCRC and its biological functions. We stained tumor tissue microarrays comprising sections of 128 CCRC tumors and found MIF to be moderately or highly expressed in >98%. MIF expression was further found to be dramatically elevated in blood plasma of individuals with CCRC compared with healthy controls, suggesting that measurement of MIF levels in the blood may have utility as a diagnostic marker in CCRC. At a functional level, MIF has been reported to engage the CD74 and CD44 receptors and induce signal transduction. In CCRC cell lines, depletion of MIF, CD74 or CD44 by small hairpin RNA led to a significant reduction in growth rate, and clonogenic survival, coinciding with the degree of knockdown. Interruption of the MIF pathway also decreased tumorigenic potential. Biochemically, we found that in CCRC cells MIF signaling leads to activation of the mitogen-activated protein kinase pathway and to Src phosphorylation, which is critical for regulation of p27. Together, our studies establish MIF as a protumorigenic signaling molecule that functions in an autocrine fashion to promote renal cell carcinoma and may be useful as a minimally invasive marker of disease status.

Socioeconomic status and children with intellectual disability in China

BACKGROUND

Intellectual disability (ID) accounts for 70% of all disabilities among children in China's Second National Sampling Survey on Disability. Although studies have shown a relationship between social class and ID in children, none have investigated the association of socioeconomic variables in Chinese children with mild or severe ID.

METHODS

Data for children aged 0-6 years with and without ID were abstracted from the Second National Sampling Survey on Disability in China, conducted in 2006. Crude odds ratios showed the effect of sociodemographic factors on mild and severe ID. Adjusted odds ratios (OR(a) ) (95% confidence intervals) estimated the independent effects of these factors.

RESULTS

For both mild and severe ID, risk of having ID increased with male sex, birth to a woman aged 35 years and older, lower maternal education, mother's older age at delivery, lower income and rural residence. After age, gender and parent disability were controlled, mothers aged 35 years and older were more likely to have a child with ID: mild ID, OR(a) 1.47 (1.15-1.88); severe ID, OR(a) 1.32 (1.00-1.73). There was an approximate increasing monotonic risk of severe ID with increasing socioeconomic disadvantage: lowest income, OR(a) 3.00 (2.19-4.12); low income, OR(a) 2.28 (1.63-3.19); lower middle income, OR(a) 1.72 (1.27-2.33); middle income, OR(a) 1.73 (1.28-2.36).

CONCLUSIONS

There is a significant relationship between sociodemographic factors and ID. Similar patterns were found for both mild and severe ID. Recommendations are given for preventing ID in Chinese children.

Nanoparticle delivery of mycophenolic acid upregulates PD-L1 on dendritic cells to prolong murine allograft survival

Conventional immunosuppressive drug delivery requires high systemic drug levels to provide therapeutic benefit, but frequently results in toxic side effects. Novel drug delivery methods, such as FDA-approved poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs), are promising drug delivery platforms to reduce drug doses and minimize toxicity. Using murine models of skin transplantation, we investigated whether PLGA NPs would effectively deliver mycophenolic acid (MPA), a common clinical immunosuppressant, and avoid the toxicity of conventional drug delivery. We found that intermittent treatment with NPs encapsulated with MPA (NP-MPA) resulted in a significant extension of allograft survival than intermittent conventional MPA treatment even though the concentration of MPA within NP-MPA was a 1000-fold lower than conventional drug. Importantly, recipients who were administered NP-MPA intermittently avoided drug toxicity, whereas those treated with daily conventional drug manifested cytopenias. Dendritic cells (DCs) endocytosed NP-MPA to upregulate programmed death ligand-1 (PD-L1) and displayed a decreased ability to prime alloreactive T cells. Importantly, the ability of NP-MPA to promote allograft survival was partly PD-L1 dependent. Collectively, this study indicates that NPs are potent drug delivery tools that extend allograft survival without drug toxicity.

Extended resections for colorectal cancer - indications for supraradical lymphadenectomy

The laparoscopic approach to standard resections in colorectal cancer has proven that it may provide equal rates of R0 resections and adequate retrieval of lymph nodes as open procedures if performed by experienced hands. There might be difficulties in more advanced tumors or those with lymphatic spread beyond typical drainage areas and more extensive operations might be required. An atypical pattern of lymphatic spread often is associated with other adverse factors such as multifocality of primary cancers and adverse tumorbiological factors such as grade. Such patient subgroups may be defined beforehand and include particularly patients with underlying ulcerative colitis. Repetitively, extended lymph node dissection approaches have been advocated, however neither in randomised trails nor in meta-analysis has a more favourable outcome of patients undergoing such extended lymphatic dissections been demonstrated. Sticking to the rules of classical dissection of lymphatic drainage basins with removal of adequate lymph node numbers is one corner stone for successful treatment of colorectal cancer. The other one refers to a detailed description of the procedure performed in order to make the surgical procedure trackable.

P2RX7 genotype association in severe sepsis identified by a novel Multi-Individual Array for rapid screening and replication of risk SNPs

BACKGROUND

Functional single nucleotide polymorphisms (SNPs) are relevant to individual therapeutic approaches and may play a role in disease susceptibility. Genome-wide scans, which are now widely applied to detect disease-associated SNPs, provide only limited evidence about SNP associations. Their usefulness as disease markers requires appropriate phenotype analysis and retesting of the gene providing SNP information. Larger data sets of thousands of samples are necessary to confirm the suggested SNPs.

METHODS

We applied a newly established microarray-based technology that significantly accelerates and simplifies such studies. A tailor-made microarray surface chemistry, sample/probe immobilization and a primer extension reaction are central to the multi-individual array (MIA) platform, which simultaneously identifies the same variable nucleotide in thousands of samples. The set of SNPs to be typed for is highly flexible and can be adapted to the demands of defined clinical questions.

RESULTS

A MIA-SNP analysis of functional SNPs in the P2RX7 calcium channel is presented. One risk genotype has been verified by functional analysis using patch clamping. Two clinically relevant genotypes composed of 5 functional SNPs in the P2RX7 gene have been identified in patients with severe sepsis and septic shock, whereas no significant association has been found in patient suffering from hemophagocytic syndromes.

CONCLUSIONS

These results support a functional SNP genotyping of the P2RX7 gene in patients at risk of severe sepsis following surgical trauma.

Intravenous administration of bone marrow mesenchymal stem cells benefits experimental autoimmune myasthenia gravis mice through an immunomodulatory action

Mesenchymal stem cells (MSC) are potent in immunomodulation. It has been proven that MSC functioned to correct immune disorder in several immune diseases. Here, we tested the hypothesis that MSC from human bone marrow (hMSC) can provide a potential therapy for experimental autoimmune myasthenia gravis (EAMG). EAMG mice model was established by subcutaneous injection of synthetic analogue of acetylcholine receptor (AchR), then, hMSC were intravenously delivered into these mice repeatedly. The results showed that hMSC could specifically home to spleen tissue and hMSC treatment significantly improved the functional deficits of EAMG mice. In addition, AchR antibody level was dramatically decreased in cell-treated group when compared with untreated control on 10 days after the second cell injection. Moreover, both in vivo and in vitro mixed lymphocyte proliferation assays revealed that hMSC could definitely inhibit the proliferation of AchR-specific lymphocyte. In conclusion, our study demonstrated that hMSC treatment was therapeutically useful in autoimmune myasthenia gravis mice, and the underlying mechanism may relate with their immunomodulatory potential.

Media framing of graduated licensing policy debates

BACKGROUND

The overrepresentation of young drivers in road trauma statistics produces significant media interest. Graduated licensing restrictions involving night-time curfews and restrictions on passenger numbers are prominent topics within media coverage. This was particularly apparent in Australia between January 2004 and July 2008, when various models of either restriction were introduced in four states.

METHODS

Australian newspaper and Sydney free-to-air television coverage during the peak period were analysed to identify the framing strategies used by news actors supporting or opposing these policies.

RESULTS

Fifteen frames were identified. These predominantly assessed the proposed restrictions in terms of their need, evidence base, practicality and the degree to which they were consonant with 'commonsense' perceptions and had community support. While expert road injury reduction news actors primarily emphasised their moral imperative and likely effectiveness, opponents stressed their impracticality and proposed alternative solutions.

CONCLUSIONS

Research evidence is only one component of information presented as policy-relevant in policy discourse conducted in news media. Policy reform advocates using the media to advocate for evidence-based policies in road injury prevention need to appreciate that evidence is not the only currency exchanged in such debates and should study opponents' rhetoric in order to anticipate and counteract the framing strategies being used.

The (-765 G→C) promoter variant of the COX-2/PTGS2 gene is associated with a lower risk for end-stage hip and knee osteoarthritis

BACKGROUND

Functional polymorphisms in genes of proinflammatory signalling cascades may contribute to the genetic risk of osteoarthritis (OA).

OBJECTIVE

To examine a possible association between end-stage OA of the hip and knee joint and a known single nucleotide polymorphism (SNP) of the COX-2 gene promoter.

METHODS

The SNP -765 G→C (rs20417) of the COX-2 gene promoter was genotyped by pyrosequencing in 531 (320 women/211 men) patients with OA from the Ulm Osteoarthritis Study and 400 (200 women/200 men) regional controls from the south-west of Germany.

RESULTS

In the whole study population the C allele was associated with a lower risk (per allele OR 0.57; 95% CI 0.43 to 0.75, p<0.0001) and the G allele with a higher risk for end-stage OA. Analysis of subgroups confirmed this result for primary, bilateral, hip and knee OA.

CONCLUSION

The promoter polymorphism rs20417 of the COX-2 gene contributes to the genetic risk for end-stage hip and knee OA.

The rb pathway and cancer therapeutics

The retinoblastoma gene, Rb, was originally identified as the tumor suppressor gene mutated in a rare childhood cancer called retinoblastoma (reviewed in [1]). Subsequent studies showed that Rb functions in a pathway that is often functionally inactivated in a large majority of human cancers. Interestingly, recent studies showed that in certain types of cancers, Rb function is actually required for cancer development. The intimate link between the Rb pathway and cancer development suggests that the status of Rb activity can potentially be used to develop targeted therapy. However, a prerequisite will be to understand the role of Rb and its interaction with other signaling pathways in cancer development. In this review, we will discuss the roles of Rb in proliferation, apoptosis and differentiation by reviewing the recent findings in both mammalian systems and different model organisms. In addition, we will discuss strategies that can be employed that specifically target cancer cells based on the status of the Rb pathway.

Suppression of p53 activity by Siva1

The tumor suppressor p53 induces potent anti-proliferative responses in stressed cells; in unstressed cells this ability of p53 is restrained by Hdm2. Expression of Hdm2 is also induced by p53, thereby establishing feedback inhibition. Regulation of the p53-Hdm2 interaction and the feedback inhibition of p53 are not well understood. Here, we show that the p53-Hdm2 interaction in unstressed cells is promoted by Siva1, which, like Hdm2, is the product of a p53 target gene. Siva1 binds to both p53 and Hdm2 through distinct regions and enhances Hdm2-mediated p53 ubiquitination and degradation. Siva1 strongly inhibits p53-mediated gene expression and apoptosis. In xenograft mouse models, downregulation of Siva1 markedly inhibits tumor formation because of the activation of p53. On DNA damage, the interactions of Siva1 with both p53 and Hdm2 are diminished. The function of Siva1 seems to be related to its ability to form a homo-oligomer as the oligomerization defective splicing variant Siva2 fails to de-stabilize p53. These results identify Siva1 as an important adaptor promoting p53 degradation through Hdm2. Siva1 may be part of the negative feedback loop that inhibits p53 activity at the end of a non-lethal stress response.