MicroRNA-206 expression levels correlate with clinical behaviour of rhabdomyosarcomas

Background:

Rhabdomyosarcomas (RMSs) are primarily paediatric sarcomas that resemble developing skeletal muscle. Our aim was to determine the effects of microRNAs (miRNA) that have been implicated in muscle development on the clinical behaviour of RMSs.

Methods:

Expression levels of miR-1, miR-206, miR-133a and miR-133b were quantified by RT–PCR in 163 primary paediatric RMSs, plus control tissues, and correlated with clinico-pathological features. Correlations with parallel gene expression profiling data for 84 samples were used to identify pathways associated with miR-206. Synthetic miR-206 was transfected into RMS cell lines and phenotypic responses assessed.

Results:

Muscle-specific miRNAs levels were lower in RMSs compared with skeletal muscle but generally higher than in other normal tissues. Low miR-206 expression correlated with poor overall survival and was an independent predictor of shorter survival in metastatic embryonal and alveolar cases without PAX3/7-FOXO1 fusion genes. Low miR-206 expression also significantly correlated with high SIOP stage and the presence of metastases at diagnosis. High miR-206 expression strongly correlated with genes linked to muscle differentiation and low expression was associated with genes linked to MAPkinase and NFKappaB pathway activation. Increasing miR-206 expression in cell lines inhibited cell growth and migration and induced apoptosis that was associated with myogenic differentiation in some, but not all, cell lines.

Conclusion:

miR-206 contributes to the clinical behaviour of RMSs and the pleiotropic effects of miR-206 supports therapeutic potential.

Primary aortoenteric fistula caused by an infected abdominal aortic aneurysm with Mycobacterium avium complex in an HIV patient

Primary aortoenteric fistula (PAEF) is a rare but complex clinical entity requiring multimodality approach for diagnosis and treatment. We report the first ever case of upper gastrointestinal (UGI) hemorrhage caused by an aortoenteric fistula (AEF) secondary to Mycobacterium avium complex (MAC) in a patient with human immunodeficiency virus (HIV) infection. Esophagogastroduodenoscopy (EGD) showed an ulcer in the distal duodenum and a computed tomography (CT) scan confirmed a contained abdominal aortic aneurysm (AAA) rupture with an aorto-enteric fistula communicating with the third portion of the duodenum. Emergent surgery was undertaken which was lifesaving. A high index of suspicion, early diagnosis and prompt surgical intervention are crucial for survival of patient with PAEF.

Targeting Aldose Reductase: A Novel Strategy in Treating Endocrine Resistance Using Combination Therapy

Breast cancer is the most commonly diagnosed form of cancer in women. Among breast cancer patients about 2/3 are initially hormone sensitive or estrogen receptor (ER) positive and respond to endocrine therapy. Aromatase inhibitors (AI's) are superior class of hormonal therapeutic agents effectively control ER positive breast cancer in postmenopausal women. Acquired resistance to AI's is expected to be an emerging serious problem in clinics and recent studies have shown that tumors use adaptive signaling mechanisms to overcome AI sensitivity. Thus there is an urgent need for newer treatment modalities. Combination of endocrine and non endocrine agents that block these signaling pathways may prevent or delay the adaptive mechanism and thereby onset of resistance to hormonal therapy. In our study we have found that Fidarestat, an aldose reductase (enzyme which catalyzes the rate limiting step of glucose to fructose or sorbitol formation in polyol pathway) inhibitor effectively re-sensitize letrozole resistant LTLT-Ca breast cancer cells to letrozole. 1µM of fidarestat + 1uM letrozole was found very effective in inducing maximum cell death in LTLT-Ca cells when compared to fidarestat alone. The combination treatment not only restored ER-α levels but also down regulated HER2/MAPK signaling proteins. Aldose reductase siRNA (100nM)- treated MCF-7/Aro and MCF-7 cells upregulated ER-α in western blot and ER-functionality assays. On the other hand in aldose reductase-siRNA- treated LTLT-Ca cells, ER-α levels were down- regulated as in fidarestat treatment. Pretreatment of LTLT-Ca with fidarestat for one week showed reduced proliferation of cells and the effect was maintained until four passages with 1µM letrozole alone. Fidarestat treatment up-regulated E2-mediated transcription in LTLT-Ca cells. In order to enhance the efficacy and targeted delivery of fidarestat in LTLT–Ca cells we have used a nanoparticle-based therapeutic formulation. Folate receptor, highly expressed on epithelial carcinomas, could be a potential molecular target for tumor selective drug delivery. Physcio-chemically well characterized Fidarestat–folate nanoparticles (FFNP's) were prepared to increase the tumor selective intracellular delivery. FFNP's were found superior in exerting cytotoxicity when compared to fidarestat alone. Combination therapy was equally effective in controlling LTLT-Ca cell growth using xenograft model. Taken together, the increased glucose metabolism in LTLT-Ca cells may be critically contributing to chemotherapeutic resistance by increasing drug metabolism and decreasing uptake. Hence targeting aldose reductase in endocrine resistance may be attractive alternative to increase the sensitivity of hormonal therapy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 67.

Blunt abdominal trauma in children: how predictive is ALT for liver injury?

BACKGROUND

The liver is the second most commonly injured intra-abdominal organ in children. CT scanning is currently regarded as the "gold standard" in screening for intra-abdominal injury following blunt trauma. However, the risks associated with performing CT in children are not insignificant and, in addition, CT is not always readily available. This study investigates the utility of alanine aminotransferase (ALT) in screening for liver injury in paediatric trauma.

METHODS

Two groups of patients were compiled from a prospectively identified trauma registry-one with liver injuries and another with intra-abdominal injuries other than to the liver. Inclusion in the study required that an initial ALT level had been obtained after injury. Where CT had been performed, a paediatric radiologist blind to the ALT results graded the severity of the liver injuries. The study groups were compared and a receiver operating characteristic (ROC) curve generated to derive the optimum ALT threshold to identify liver injury.

RESULTS

51 patients with liver injury and 65 with other intra-abdominal injuries were identified. An ALT level of > or =104 IU/l gave a sensitivity of 96% and a specificity of 80%. When liver injuries were stratified to identify only clinically significant liver injuries (grades III, IV and V), this ALT threshold identified 100% of patients with 70% specificity.

CONCLUSIONS

In this sample, ALT appears to be a useful predictor for the presence or absence of liver injury. In haemodynamically stable children with clinical suspicion of isolated liver injury, identification of a normal ALT level (<104 IU/l) may reduce the need for unnecessary transportation for CT scanning with subsequent radiation exposure.

Occupational health and safety status of indigenous and Latino farmworkers in Oregon

Exposure to pesticides poses great risk to agricultural workers and their families. Of the approximately 174,000 agricultural workers in Oregon, studies estimate that up to 40% of the workers in Oregon are indigenous and may be particularly vulnerable to the health risks of working in pesticide treated areas. Surveys conducted with Oregon farmworkers suggest that Latino and indigenous farmworkers differ demographically and may have diverse occupational and health needs. All Latino workers reported Spanish as their native language, while indigenous workers spoke several different native languages. Latino workers were employed mostly in orchards (28%) and nurseries (24%), while indigenous workers were mostly pickers (40%). Indigenous farmworkers reported less frequent suitable occupational safety training, and potentially less knowledge of the health consequences of pesticides. Addressing the barriers to obtaining pesticide health and safety information is of primary importance, given the changing demographics of farmworkers in Oregon. This article concludes with a discussion of these findings and the programmatic activities that have been implemented in Oregon to improve farmworkers' understanding of hazards and rights associated with agricultural work.

Management of hyperbilirubinemia in biliary atresia by hepatic progenitor cell transplantation through hepatic artery: a case report

Cholangiodestruction of bile ducts leads to biliary atresia, a rare disease characterized by intrahepatic and extrahepatic biliary inflammation. If the intrahepatic biliary tree is unaffected, surgical reconstruction by the Kasai procedure of hepatoportoenterostomy of the extra hepatic biliary tract is possible. Untreated, this condition leads to cirrhosis and death within the first year of the life. If the atresia is complete, liver transplantation is the only option. As a result of the shortage of donor livers, hepatocytes have been infused over the past two decades, providing proof of the concept that cell therapy can be effective for the treatment of liver diseases. In the present study, we report a confirmed case of a girl of 1 year of age with increased bilirubin of 28.5 mg/dL and pediatric end-stage liver disease score 20. Biochemical liver function tests showed cholestasis (elevated cholesterol and gamma-GTs) and increased ALT, total bilirubin, conjugated bilirubin, and ALP. The patient was treated with hepatic progenitor cell infusion through the hepatic artery. The total bilirubin and conjugated bilirubin started decreasing during the first month after cell infusion. The level of total bilirubin maintained a threefold decrease after months of cell infusion. The conjugated bilirubin was 16.35 mg/dL before cell infusion, decreasing to eightfold after cell infusion. After 2 months of cell infusion, hepatobiliary scintigraphy showed increased liver cell function. This case demonstrated the efficacy and functionality of hepatic progenitor cells for the management of biliary atresia. Further, as there was a decrease in serum bilirubin, it showed that there was some percentage of the engraftment of the infused cells. As the procedure is simple and the patient has tolerated the infusion therapy, it might be repeated to manage biliary atresia.