Overexpression of Protein Phosphatase 2 Regulatory Subunit B"Alpha Promotes Glycolysis by Regulating Hexokinase 1 in Hepatocellular Carcinoma / 生物医学与环境科学（英文）

Objective@#To investigate the regulatory relationship of Protein Phosphatase 2 Regulatory Subunit B"Alpha ( PPP2R3A) and hexokinase 1 ( HK1) in glycolysis of hepatocellular carcinoma (HCC).@*Methods@#In HepG2 and Huh7 cells, PPP2R3A expression was silenced by small interfering RNA (siRNA) and overexpression by plasmid transfection. The PPP2R3A-related genes were searched by RNA sequencing. Glycolysis levels were measured by glucose uptake and lactate production. QRT-PCR, ELISA, western blot and immunofluorescence assay were performed to detect the changes of PPP2R3A and HK1. Cell proliferation, migration and invasion assay were used to study the roles of HK1 regulation by PPP2R3A.@*Results@#RNA sequencing data revealed that PPP2R3A siRNA significantly downregulated the expression of HK1. PPP2R3A gene overexpression promotes, while gene silencing suppresses, the level of HK1 and glycolysis in HCC cells. In HCC tissue samples, PPP2R3A and HK1 were colocalized in the cytoplasm, and their expression showed a positive correlation. HK1 inhibition abrogated the promotion of glycolysis, proliferation, migration and invasion by PPP2R3A overexpression in liver cancer cells.@*Conclusion@#Our findings showed the correlation of PPP2R3A and HK1 in the glycolysis of HCC, which reveals a new mechanism for the oncogenic roles of PPP2R3A in cancer.

Comparative analysis of a panel of biomarkers related to protein phosphatase 2A between laryngeal squamous cell carcinoma tissues and adjacent normal tissues / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Laryngeal squamous cell carcinoma (LSCC) is the most common type of head and neck squamous cell carcinoma (HNSCC) worldwide. Protein phosphatase 2A (PP2A) dysfunction has been widely reported in a broad range of malignancies due to its distinctive role in miscellaneous cellular processes. However, it is poorly understood whether aberrant alterations of PP2A are involved in the network of oncogenic events in LSCC. Here, we detected a panel of PP2A-associated proteins using western blot in both laryngeal squamous cell carcinoma tissues and paired adjacent normal tissues from patients (Data S1). We found that phospho-PP2A/C (Y307), α4, cancerous inhibitor of protein phosphatase 2A (CIP2A), Akt, ezrin, phospho-ezrin (T567), 14-3-3, and focal adhesion kinase (FAK) showed increased expression levels in carcinoma tissues relative to normal tissues, while phospho-Akt (T308) showed decreased levels. Our study, thus, provides a rationale for targeting PP2A to develop novel therapies and proposes a combination of interrelated biomarkers for the diagnostic evaluation and prognosis prediction in LSCC.

Comparative proteomic analysis of the nucleus accumbens during extinction and reinstatement of morphine dependence / Análisis proteómico comparativo del núcleo accumbens durante laextinción y recaída de la dependencia a la morfina

BACKGROUND: The aim of this study was to detect differentially expressed proteins in the nucleus accumbens between the states of extinction and reinstatement of morphine addiction. Numerous studies on the neurobiological mechanisms concerning drug craving and relapse have been reported to date, but data on their relationship with the underlying key molecular mechanisms involved remain limited. METHODS: In this study, 40 male SpragueDawley rats were equally randomized into a saline group and a morphine group. Both groups received drug selfadministration training, after which extinction models were established naturally. The groups were further divided into two subgroups for extinction and reinstatement tests. Cerebral nucleus accumbens masses were measured for total protein extraction. Twodimensional electrophoresis was performed to determine differential protein spots. These differential proteins were then enzymolysed and identified using mass spectrography. RESULTS: The proteins were classified as fatty acidbinding protein, serine/threonine protein phosphatase 2A catalytic subunit beta isoform, serine/threonine protein phosphatase 2A catalytic subunit alpha isoform, serine/threonine protein phosphatase 2A regulatory subunit B² subunit gamma or heat shock protein 90 cochaperone CDC37. CONCLUSION: Significant changes in five proteins were detected between extinction and reinstatement. These proteins are correlated with phosphorylation and the tricarboxylic acid cycle.

ANTECEDENTES: El objetivo de este estudio fue detectar las proteínas diferencialmente expresadas en el núcleo accumbens entre los estados de extinción y recaída de la adicción a la morfina. Hasta la fecha se han reportado numerosos estudios en relación con los mecanismos neurobiológicos del deseo incontenible y recaída en el consumo de drogas, pero los datos sobre su relación con los mecanismos moleculares fundamentales subyacentes implicados, siguen siendo limitados. MÉTODO: En este estudio, 40 ratas machos SpragueDawley fueron por igual asignadas de manera aleatoria a un grupo salino y un grupo de morfina. Ambos grupos recibieron entrenamiento de autoadministración de drogas, después de lo cual se establecieron modelos de extinción de manera natural. A su vez, los grupos fueron luego subdivididos en dos subgrupos para realizar pruebas de extinción y recaída. Se procedió a medir las masas cerebrales del núcleo accumbens para la extracción total de proteína. Se realizó una electroforesis bidimensional para determinar manchas proteicas diferenciales. Estas proteínas diferenciales fueron entonces sometidas a enzimólisis e identificadas mediante espectrografía de masa. RESULTADOS: Las proteínas fueron clasificadas como proteína de unión a ácidos grasos, isoforma beta de la subunidad catalítica serinatreonina proteína fosfatasa 2A, isoforma alfa de la subunidad catalítica serinatreonina proteína fosfatasa 2A, subunidad gamma subunidad B" de la serinatreonina proteína fosfatasa 2A, o la proteína CDC37 cochaperona 90 de choque térmico. CONCLUSIÓN: Se detectaron cambios significativos en cinco proteínas entre la extinción y la recaída. Estas proteínas están correlacionadas con la fosforilación y el ciclo del ácido tricarboxílico.