Amyloid precursor protein regulates 5-fluorouracil resistance in human hepatocellular carcinoma cells by inhibiting the mitochondrial apoptotic pathway / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Hepatocellular carcinoma (HCC) is a malignant tumor with high morbidity and mortality globally. It accounts for the majority of primary liver cancer cases. Amyloid precursor protein (APP), a cell membrane protein, plays a vital role in the pathogenesis of Alzheimer's disease, and has been found to be implicated in tumor growth and metastasis. Therefore, to understand the relationship between APP and 5-fluorouracil (5-FU) resistance in liver cancer, Cell Counting Kit-8, apoptosis and cell cycle assays, western blotting, and reverse transcription-quantitative polymerase chain reaction (qPCR) analysis were performed. The results demonstrated that APP expression in Bel7402-5-FU cells was significantly up-regulated, as compared with that in Bel7402 cells. Through successful construction of APP-silenced (siAPP) and overexpressed (OE) Bel7402 cell lines, data revealed that the Bel7402-APP751-OE cell line was insensitive, while the Bel7402-siAPP cell line was sensitive to 5-FU in comparison to the matched control group. Furthermore, APP overexpression decreased, while APP silencing increased 5-FU-induced apoptosis in Bel7402 cells. Mechanistically, APP overexpression and silencing can regulate the mitochondrial apoptotic pathway and the expression of apoptotic suppressor genes (B-cell lymphoma-2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xl)). Taken together, these results preliminarily revealed that APP overexpression contributes to the resistance of liver cancer cells to 5-FU, providing a new perspective for drug resistance.

Comparing TCR beta chain variable gene profile skewness between children with tuberculosis and BCG-vaccinated children

We compared the T cell antigen receptor [TCR-BV] gene families of peripheral blood mononuclear cells [PMBC] between children with tuberculosis [TB] and those inoculated with the Bacille Calmette Guerin [BCG] vaccine. The total RNA was extracted from PMBC of 15 TB children, 15 BCG-vaccinated children and 15 healthy controls. The RNAs were reverse-transcribed and amplified by polymerase chain reaction [PCR]. PCR products were separated on 1.5% agarose gel and analyzed with the Genescan technique. Some TCR-BV gene families in TB children and BCG-vaccinated children exhibited a blur band in the predicted position on 1.5% agarose gel, some showed a distinct or fainted band. In general, many shared predominant clonal TCR-BV gene families [V beta2, V beta16, V beta21, V beta22] and the restricted-expression families [V beta14 and V beta17]. All the gene families of the control children only exhibited blur bands and polyclonal. The skewed profile of TCR-BV gene families in TB children and BCG-vaccinated children are similar, which may probably explain the protective effects of BCG-vaccine against TB in children