Epigenetic regulation of REG1A and chemosensitivity of cutaneous melanoma

Regenerating gene 1A (REG1A) plays an important role in tissue regeneration and in cell proliferation in epithelium origin tumors; however, its role in melanoma has not been explored in details. The objective of this study was to identify whether REG1A is expressed in cutaneous melanoma and if REG1A expression status can predict prognosis in cutaneous melanoma patients with metastasis. We also determined whether epigenetic regulation of the promoter region regulates REG1A expression. AJCC stage III cutaneous melanoma specimens with clinically well annotated stage III lymph node melanoma metastasis tissue microarray were assessed by IHC. MALDI-TOF-mass spectrometry and HM450K array were used to identify REG1A promoter region CpG site methylation. Chemotherapeutic agent response by melanoma cells as related to REG1A protein expression was assessed. Post-surgery melanoma patients followed by adjuvant chemotherapy with high REG1A expression had a significantly better prognosis (disease-specific survival) compared with patients with low REG1A expression (log rank test; p = 0.0013). The demethylating reagent 5-Aza-2′-deoxycytidine activated REG1A promoter region resulting in enhanced REG1A mRNA and protein expression in melanoma cell lines. Promoter region CpG methylation was shown to regulate REG1A expression in melanoma cells. Moreover, melanoma lines with high REG1A mRNA expression were more susceptible to Dacarbazine and Cisplatin, as compared with those with low REG1A mRNA expression. In conclusion, REG1A expression status may be useful as a biomarker in melanoma patients for sensitivity to these chemotherapeutic agents. The epigenetic regulation of the REG1A promoter region may offer a potential therapeutic approach to improve chemotherapy for metastatic melanoma patients.     

The secreted effector protein of Salmonella dublin, SopA, is translocated into eukaryotic cells and influences the induction of enteritis

Salmonella -induced enteritis is associated with the induction of an acute intestinal inflammatory response and net fluid secretion into the lumen of infected mucosa. Proteins secreted by the Inv/Spa type III secretion system of Salmonella play a key role in the induction of these responses. We have demonstrated recently that the Inv/Spa-secreted SopB and SopD effector proteins are translocated into eukaryotic cells via a Sip dependent pathway and act in concert to mediate inflammation and fluid secretion in infected ileal mucosa. Mutations of both sopB and sopD significantly reduced, but did not abrogate, the enteropathogenic phenotype. This indicated that other virulence factors are involved in the induction of enteritis. In this work, we characterize SopA, a secreted protein belonging to the family of Sop effectors of Salmonella dublin . We demonstrate that SopA is translocated into eukaryotic cells and provide evidence suggesting that SopA has a role in the induction of enteritis.     

Phylogeography, genetic structure, and diversity in the dhole (Cuon alpinus)

The Asiatic wild dog or dhole was once very widely distributed across Asia but now has a very fragmented range. In this first genetic study of this little-known species, we obtained information on genetic diversity, phylogeography, and social structure using both mitochondrial control region sequencing and microsatellite genotyping of noninvasive faecal samples from wild populations, as well as from museum and captive samples. A pattern largely consistent with isolation by distance across the Asian mainland was observed, with no clear subspecies distinctions. However, two major phylogeographical groupings were found across the mainland, one extending from South, Central, and North India (south of the Ganges) into Myanmar, and the other extending from India north of the Ganges into northeastern India, Myanmar, Thailand and the Malaysian Peninsula. We propose a scenario involving glaciation events that could explain this pattern. The origin of the dhole populations in Sumatra and Java is enigmatic and requires further study. Very low levels of genetic diversity were observed among wild dholes from Baluran National Park in Java, Indonesia, but in contrast, high levels were observed in Mudumalai Wildlife Sanctuary in South India.     

Calibration of avian molecular clocks

Molecular clocks can be calibrated using fossils within the group under study (internal calibration) or outside of the group (external calibration). Both types of calibration have their advantages and disadvantages. An internal calibration may reduce extrapolation error but may not be from the best fossil record, raising the issue of nonindependence. An external calibration may be more independent but also may have a greater extrapolation error. Here, we used the advantages of both methods by applying a sequential calibration to avian molecular clocks. We estimated a basal divergence within birds, the split between fowl (Galliformes) and ducks (Anseriformes), to be 89.8 +/- 6.97 MYA using an external calibration and 12 rate-constant nuclear genes. In turn, this time estimate was used as an internal calibration for three species-rich avian molecular data sets: mtDNA, DNA-DNA hybridization, and transferrin immunological distances. The resulting time estimates indicate that many major clades of modern birds had their origins within the Cretaceous. This supports earlier studies that identified large gaps in the avian fossil record and suggests that modern birds may have coexisted with other avian lineages for an extended period during the Cretaceous. The new time estimates are concordant with a continental breakup model for the origin of ratites.     

Effect of a hydantoin prostaglandin analogue, BW245C, during oral dosing in man

Following an open pilot study, the effects of repeated oral doses of BW245C, a hydantoin prostaglandin analogue, were studied in man. Six healthy volunteers received 150 micrograms BW245C or placebo 6-hourly for 5 days according to a double blind randomised balanced design with 7 days interval between treatments. Measurements of headache, facial flushing, heart rate, blood pressure, systolic time intervals, ECG, platelet aggregation responses to ADP and of subjective effects were made before and 1 and 3 h after the first dose of BW245C/placebo on days 1, 3 and 5 of dosing. BW245C produced significantly (p less than 0.05) higher headache scores than placebo on days 3 and 5; facial flushing, nasal stuffiness and abdominal discomfort were more frequent on BW245C than placebo. Heart rate, derived from the ECG, was significantly (p less than 0.05) higher and pre-ejection period significantly (p less than 0.05) shorter on BW245C at 1 h after dosing on each day. Left ventricular ejection time index, QS2 index, PR interval, QRS duration and T wave height were unchanged. Heart rate, counted at the radial pulse, and systolic and diastolic blood pressure, all measured lying and standing, were similar for BW245C and placebo. Platelet aggregation responses were not significantly different between the two treatments. The results indicate that repeated oral doses of BW245C, sufficient to cause moderately uncomfortable subjective effects, do not inhibit platelet aggregation.