Objective:To analyze the expression of LETM2 in KYSE150 and ECA109 cell lines and its effect on the proliferation, migra-tion, and invasion of esophageal squamous cell carcinoma (ESCC). Methods:The expression level of the LETM2 protein in 90 paired hu-man ESCC tissues and matched adjacent normal tissues was determined through immunohistochemistry. The expression level of LETM2 in ESCC cell lines was detected by real-time PCR and Western blot. The expression levels of LETM2 in KYSE150 and ECA109 cell lines were knocked down using lentivirus. MTT assays were performed to examine the effect of LETM2 on the proliferation of ESCC cells. Colony formation assay was used to detect the colony formation ability. Flow cytometry was performed to analyze the cell cycle. The effect of LETM2 depletion on the migration and invasion of ESCC cells was determined by Transwell assay. Results:LETM2 expres-sion was frequently upregulated in the ESCC tissues than in the adjacent normal tissues. The suppressed exogenous expression of LETM2 led to the inhibition of cell proliferation and colony formation. However, cell migration and invasion were not affected. The re-sults on the cell cycle distribution revealed that LETM2 knockdown acts as a negative regulator of the cell cycle at the G1 to S phase transition. Conclusion:LETM2 acts as a tumor-driven gene in the development and progression of ESCC. This finding suggests that LETM2 can be used as an efficient prognosis biomarker and a potential therapeutic target for ESCC.

In carbohydrate chemistry, the stereoselective synthesis of 1,2-cis-glycosides remains a formidable challenge. This complexity is comparable to the synthesis of 1,2-cis-β-D-mannosides, primarily due to the adverse anomeric and Δ-2 effects. Over the past decades, to attain β-stereoselectivity in D-rhamnosylation, researchers have devised numerous direct and indirect methodologies, including the hydrogen-bond-mediated aglycone delivery (HAD) method, the synthesis of β-D-mannoside paired with C6 deoxygenation, and the combined approach of 1,2-trans-glycosylation and C2 epimerization. This review elaborates on the advancements in β-D-rhamnosylation and its implications for the total synthesis of tiacumicin B and other physiologically relevant glycans.
Glycosides ; Mannosides ; Glycosylation ; Stereoisomerism