Recent advances of studies on role of mTOR signaling in aging of hematopoietic and other organ systems-review / 中国实验血液学杂志

Mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase, which plays an essential role in cell growth, proliferation and survival. mTOR regulates the transcription of mRNA, synthesis of ribosome and gene expression for metabolism. By forming mTOR complex, it regulates cellular activities by phosphorylating its downstream proteins, such as S6 protein kinase and 4E-BP1. In recent years, the role of mTORC1 in regulating aging is gradually recognized. Studies of physiological function and the regulatory mechanisms of mTOR signaling can not only help to better understand the aging mechanism for cells or organs, but also provide insights as to finding potential new drug targets for aging related diseases. This review focuses on recent advances of mTOR and aging related diseases in hematopoietic and other organ systems.

Regulatory mechanisms of PI3K/AKT signaling pathway in acute leukemia / 中国实验血液学杂志

This study was aimed to analyze the expression profiles of PI3K/AKT signaling pathway genes from bone marrow samples of AML and ALL patients and normal samples. AML, ALL and normal bone marrow samples were collected from 6 AML, 6 ALL patients and 4 normal persons. The expression of PI3K/AKT signaling pathway genes including PTEN, CCND1, mTOR, RICTOR, FOXO1 were detected by real-time fluorescent quantification RT-PCR while GAPDH gene expression was used as an internal reference. The relative gene expression level was calculated by the method of the 2(-ΔΔCt). The results showed that the gene expression profiles were different between normal and leukemic groups. PTEN, mTOR and RICTOR expression levels were down-regulated, while FOXO1 and CCND1 levels were up-regulated in AML and ALL. PTEN was down-regulated in 10 out of the 12 samples; mTOR was down-regulated in 9 out of the 12 samples; RICTOR was down-regulated in 7 out of the 12 samples; FOXO1 was up-regulated in 9 out of the 12 samples and CCND1 was up-regulated in 7 out of the 12 samples. It is concluded that PI3K/AKT signal pathway is activated in both AML and ALL leukemic cells.