BackgroundThe aim of this study was to detect the expression of hypoxia-inducible factor (HIF)-1α and HIF-2α in papillary thyroid carcinoma (PTC) compared with normal thyroid tissues.MethodsThe mRNA levels and protein levels of HIF-1α and HIF-2α were detected by real-time PCR and Western blot separately in 30 pairs of PTCs and normal thyroid cases. The protein levels were also detected by immunohistochemistry (IHC) using 92 samples of PTC group and 46 normal samples as control group for analyzing the biological and clinical significance of the expression of HIF-1α/HIF-2α.ResultsReal-time PCR results showed the mRNA level of HIF-1α and HIF-2α were significantly higher in PTC than normal group (P < 0.001). Also, significantly higher positive rates (73 %/65 %) of HIF-1α and HIF-2α were observed in PTC compared with the control group (27 %/35 %) by IHC (P < 0.01); the consistent results were gotten with Western blot. Although we did not find a significant correlation between the expression of HIF-1α and HIF-2α with gender, age, calcification, or Hashimoto’s disease in the present study (P > 0.05), both of their expressions were correlated to lymph node metastasis (P < 0.05), capsular invasion (P < 0.05), and TNM stage (P < 0.05).ConclusionsOverexpression of HIF-1α and HIF-2α are associated with the carcinogenesis of PTC, served as potential biomarkers of PTC.

Subject area Strategic management. Study level/applicability This case is suitable for graduate students, postgraduate students and MBAs. Case overview YC Company is a foreign trade SME operating in the lighting fixtures export business in Ningbo City, a major outdoor lighting products manufacturing base in mainland China. Established by Li Lele in 2008, the sales revenue and gross profit of YC Company have been increasing every year, reaching $ 4.06 million and ¥ 1.00 million, respectively, by the end of 2011. However, the growth rate of profit lagged far behind the growth of sales revenue. If this situation were not controlled, YC Company would hardly survive in this increasingly competitive market. Li Lele, the CEO of the company, was trying to find a way to enlarge the profit margin. Expected learning outcomes This case lets students learn more about strategic management. Students are expected to learn: how to precisely identify and map a problem; and how to select a better solution by analyzing the context and using some strategic analysis tools, such as Porter's Five Power, Smile Curve, SWOT. In the learning process, students are expected to acquire a better knowledge of some strategic management theory/method, international business, the condition of small and medium trading companies in China. Supplementary materials Teaching notes are available for educators only. Please contact your library to gain login details or email support@emeraldinsight.com to request teaching notes.