Novel methylation gene panel in adjacent normal tissues predicts poor prognosis of colorectal cancer in Taiwan

BACKGROUND It is evident that current clinical criteria are suboptimal to accurately estimate patient prognosis.Studies have identified epigenetic aberrant changes as novel prognostic factors for colorectal cancer(CRC).AIM To estimate whether a methylation gene panel in different clinical stages can reflect a different prognosis.METHODS We enrolled 120 CRC patients from Tri-Service General Hospital in Taiwan and used the candidate gene approach to select six genes involved in carcinogenesis pathways.Patients were divided into two groups based on the methylation status of the six evaluated genes,namely,the<3 aberrancy group and≥3 aberrancy group.Various tumor stages were divided into two subgroups(local and advanced stages)on the basis of the pathological type of the following tissues:Tumor and adjacent normal tissues(matched normal).We assessed DNA methylation in tumors and adjacent normal tissues from CRC patients and analyzed the association between DNA methylation with different cancer stages and the prognostic outcome including time to progression(TTP)and overall survival.RESULTS We observed a significantly increasing trend of hazard ratio as the number of hypermethylated genes increased both in normal tissue and tumor tissue.The 5-year TTP survival curves showed a significant difference between the≥3 aberrancy group and the<3 aberrancy group.Compared with the<3 aberrancy group,a significantly shorter TTP was observed in the≥3 aberrancy group.We further analyzed the interaction between CRC prognosis and different cancer stages(local and advanced)according to the methylation status of the selected genes in both types of tissues.There was a significantly shorter 5-year TTP for tumors at advanced stages with the promoter methylation status of selected genes than for those with local stages.We found an interaction between cancer stages and the promoter methylation status of selected genes in both types of tissues.CONCLUSION Our data provide a significant association between the methylation markers in normal tissues with advanced stage and prognosis of CRC.We recommend using these novel markers to assist in clinical decision-making.

Impacts of Land Cover Changes on Runoff and Sediment in the Cedar Creek Watershed,St.Joseph River,Indiana,United States

The relation between runoff and sediment and land cover is investigated in the Cedar Creek Watershed (CCW), located in Northeastern Indiana, United States. The major land cover types in this watershed are cultivated land, woodland and pasture /Conservation Reserve Program (CRP), which account for approximate 90 % of the total area in the region. Moreover, land use was changed tremendously from 2000 to 2004, even without regarding the effect of the crop rotation system (corn & soybean). At least 49 % of land cover types were changed into other types in this period. The land cover types, ranking by changing area from high to low series, are rye, soybean, corn, woodland and pasture/CRP. The CCW is divided into 21 sub- watersheds, and soil and water loss in each sub-watershed is computed by using Soil and Water Assessment Tool (SWAT). The results indicate that the variations in runoff and sediment have positive relation to the area of crops (especially corn and soybean); sediment is more sensitive to land cover changes than runoff; more heavy rainfall does not always mean more runoff because the combination of different land cover types always modify runoff coefficient; and rye, soybean and corn are the key land cover types, which affected the variation in runoff and sediment in the CCW.

Erosion and covered zones altered by surface coverage effects on soil nitrogen and carbon loss from an agricultural slope under laboratorysimulated rainfall events

Soil erosion,one of the most serious environmental concerns,might remove topsoil and essential element from terrestrial land.However,few attentions have been given to investigating how soil erosion regimes affect soil carbon and nitrogen loss.Therefore,this study investigated the effects of surface coverage rates(83%,67%,50%,33%,17%and 0%)and two positions(up-and downslope)on erosion regimes and its associated soil nitrogen and carbon loss under a sequence of six rainfalls(R1-R6).These results showed that the sediment concentrations with 33%(R4)and 17%(R5)coverage downslope were significantly lower than those with coverage upslope,whereas there was no significant difference between the runoff rates of the two slopes.Thus,surface coverage at different positions induced two soil erosion regimes(deposition-and transport-dominated processes).Dynamics of the DON and DIN concentrations indicated different release processes of soil nitrogen into runoff.The DON contributed to a substantial amount of soil nitrogen loss,which accounted approximately 81%of the organic form.The SBOC is significantly correlated with sediment-enriched clay particles from the deposition-dominated processes and is higher than that from the transport-dominated processes.The DOC is significantly correlated with Rr for transport-dominated processes.These results illustrated the critical role of erosion regimes in soil organic carbon loss in dissolved or sediment-bound form.It is concluded that erosion/covered zones altered by surface coverage could produce transport-and deposition-dominated erosion regimes and consequently affect soil carbon and nitrogen loss.In addition,these results demonstrated that surface coverage pattern may efficiently control soil erosion and soil carbon and nitrogen loss.

An updated isoerodent map of the conterminous United States

Maps of erosivity,which are also commonly referred to as isoerodent maps,have played a critical role in soil conservation efforts in the United States and around the world.Currently available erosivity maps for the United States are either outdated,conflict with erosivity benchmarking studies,or utilized less advanced spatial mapping methods.Furthermore,it is possible that the same underlying issues with US maps are impacting global maps as well.In this study,we used more than 340015-min,fixed-interval precipitation gauges to update the isoerodent map of the conterminous United States.Erosivity values were interpolated using universal kriging under several spatial model configurations and resolutions.The optimal spatial model was selected based on which result had the lowest sample variogram error.Rainfall,erosivity,and erosivity density maps were compared to existing products.Some average annual and annual erosivity results were compared to high-quality erosivity benchmarking publications.Erosivity values from both RUSLE2 and Panagos et al.(2017)were generally lower in the eastern United States and mixed in the western United States compared to our results.Topographic effects resulted in much greater erosivity differences in this study as compared to prior maps.Benchmark comparisons revealed that erosivity maps from this study and others were lower than the benchmark by 14%or more(up to 38%).These findings suggest current practices of storm omission and intensity dampening correction need to be revisited,especially in locations with relatively low-to-moderate rainfall erosivity such as the Midwest or Northeast United States,for example.