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Long noncoding RNAs (lncRNAs) play critical roles in tumour progression and metastasis. Emerging evidence indicates that the lncRNA X inactive-specific transcript (XIST) is dysregulated in several tumor types, including non-small cell lung cancer (NSCLC). However, in NSCLC and other cancers the oncogenic mechanism of XIST remains incompletely understood. Here, we confirmed that XIST is upregulated in human NSCLC specimens, and is especially overexpressed in tumors previously treated with cisplatin (cis-diamminedichloroplatinum(II); DDP). In vitro, XIST knockdown inhibited NSCLC cell growth and promoted DDP chemosensitivity by stimulating apoptosis and pyroptosis. Moreover, XIST's oncogenic effects and ability to promote DDP chemoresistance were largely related to its binding to the TGF-β effector SMAD2, which inhibited its translocation to the nucleus and prevented the transcription of p53 and NLRP3, crucial regulators of apoptosis and pyroptosis, respectively. Using DDP-resistant NSCLC cells, mouse xenograft studies verified the oncogenic function of XIST and its ability to inhibit programmed cell death, thereby mediating DDP chemoresistance. These findings suggest that XIST expression may serve as a novel biomarker to predict DDP treatment efficacy, and may help in the design of new therapies to circumvent DDP chemoresistance in NSCLC and other tumor types.

May-September temperatures were reconstructed for the past 250 yr based on Dahurian larch Larix gmelinii Rupr. growing in permafrost region of Northeast China. The reconstruction accounts for 39.3% of the actual temperature variance over the period . The reconstruction captured 3 relatively cold periods in 1847-1852, 1861-1866 and 1935-1941; 2 relatively warm periods in 1874-1879 and 2001-2008; and a persistent warming trend since the mid-20th century. The longterm changes in temperature documented here correspond well with regional temperature change from observational records, other global and regional proxy-based temperature reconstructions, and documented changes in regional permafrost. Thus, valuable information might be preserved in our reconstruction about local-to regional-scale climatic variation during the past 2.5 centuries.KEY WORDS: Tree-ring width · Temperature reconstruction · Dahurian larch · Permafrost change · Climatic variation Resale or republication not permitted without written consent of the publisherClim Res 47: 151-159, 2011 152 for the southern Northeast regions (Shao & Wu 1997, Zhu et al. 2009), and none are available for the permafrost-dominated northern regions.Furthermore, the rapid increase in temperature in high-latitude areas of Northeast China (Qian & Lin 2004) suggests that the ecosystems of this region will potentially undergo large impacts arising from climate change. The permafrost in this region (0.38 × 10 6 km 2 , accounts for 17.67% of the total area of permafrost in China; Jin et al. 2000) is quite sensitive to changes in temperature (Kääb et al. 2007). Incremental changes in temperature are a well documented cause of permafrost degradation during the 20th century (Zhou et al. 2003, Osterkamp 2005, Harris et al. 2009). Changes in permafrost stemming from continually rising temperatures will likely necessitate alternatives in building and road engineering, construction practices, water resources, and forest products (Jin et al. 2000, Zhou et al. 2002, Yang et al. 2010. Moreover, it can cause severe environmental changes for tree growth. Thus, in order to contextualize recent and potential temperature changes in the future, it is necessary to produce a long-term temperature reconstruction for this region using tree-ring records. Accordingly the major goals of the present study are: (1) to determine the climate-growth relationships of local trees relative to biophysically important variables (temperature, precipitation); (2) to investigate the linkages between regional temperature change and other records documenting regional to global-scale changes in temperature; and (3) to assess the influences of permafrost degradation induced by past temperature variations on radial growth. MATERIALS AND METHODS Study area and sampling sitesThe study area is located in the western Great Xing'an Mountain, a dividing zone of dry/wet and cold/ warm climate in northeastern China and a typical monsoon boundary zone (continental monsoon climate) (Fig. 1). The sampling site (51°...

Vegetation types are generally classified based only on remote sensing vegetation data, and yet they cannot reflect their connection with climate. Climatic vegetation types reflect the regional vegetation characteristics in terms of climate. The distribution of global climatic vegetation types were identified by K‐means method based on vegetation and climate data. Fourteen climatic vegetation types were classified based on vegetation and climate data. Every type had distinct climate and vegetation characteristics. The regions with similar normalized difference vegetation index (NDVI) values but with different climate values such as tropical desert and temperate desert could be distinguished. Our new updated climatic vegetation types agreed ‘fair’ with Koeppen climate types and climate type of Zhang and Yan while agreed ‘good’ with vegetation types when checked with Kappa test.