Valproic acid promotes mature neuronal differentiation of adipose tissue-derived stem cells through iNOS-NO-sGC signaling pathway
NITRIC OXIDE-BIOLOGY AND CHEMISTRY
Authors: Okubo, Takumi; Fujimoto, Shinri; Hayashi, Daiki; Suzuki, Takehito; Sakaue, Motoharu; Miyazaki, Yoko; Tanaka, Kazuaki; Usami, Makoto; Takizawa, Tatsuya
Abstract
Valproic acid (VPA) remarkably promotes the differentiation of adipose tissue-derived stem cells (ASCs) to mature neuronal cells, enabling neuronal induction within only three days. Here, we investigated the involvement of NO-signaling in the VPA-promoted neuronal differentiation of ASCs as a possible mechanism. Cultured rat ASCs were differentiated to matured neuronal cells rich in dendrites and expressing 13III-tubulin protein, a neuronal marker, by treatments with VPA at 2 mM for 3 days and subsequently with the neuronal induction medium (NIM) containing cAMP-elevating agents for 2 h. Increased intracellular NO was detected in neuronal cells differentiated from ASCs treated with VPA by a fluorescence NO-specific probe, diaminofluorescein-FM diacetate. However, a NO donor (NOC18) increased the incidence of neuronal cells only to a lesser extent than VPA, indicating the insufficiency of exogenous NO. RT-PCR analysis of ASCs treated with VPA showed increased mRNA expression of inducible nitric oxide synthase (iNOS) with the acetylation of its associated histone H3K9. iNOS inhibitors (1400 W and dexamethasone) or a soluble guanylate cyclase (sGC) inhibitor (ODQ) decreased the incidence of neuronal cells differentiated from ASCs treated with VPA. These inhibitors also decreased the mRNA expression of mature neuronal markers, neurofilament medium polypeptide (NeFM) and microtubule-associated protein 2 (MAP2), as well as beta III-tubulin (TUBB3), to various extents. It was considered from these results that VPA promoted mature neuronal differentiation of ASCs through the iNOS-NO-sGC signaling pathway. This provided insights into the regulated neuronal differentiation of ASCs in clinical applications.
Exome and transcriptome sequencing identifies loss of PDLIM2 in metastatic colorectal cancers
CANCER MANAGEMENT AND RESEARCH
Authors: Oh, Bo Young; Cho, Jeonghee; Hong, Hye Kyung; Bae, Joon Seol; Park, Woong-Yang; Joung, Je-Gun; Cho, Yong Beom
Abstract
Background: Understanding the genomic determinants associated with metastasis in colorectal cancers (CRCs) provides crucial clues for improving patient care. Patients and methods: In this study, we performed whole-exome sequencing as well as RNA sequencing analyses on five pairs of primary and liver metastasized samples from CRC patients together with blood/normal control samples for each pair. Results: We identified genomic deletions in the region of 8p21-23 (q value < 0.01) from analysis of recurrent regions with copy number variations in both primary and matched metastatic lesions. Consistent with this result, we found significantly decreased expression levels of all 12 genes (ADAMDEC1, C8orf80, CLDN23, EPHX2, GFRA2, NEFL, NEFM, PDLIM2, PTK2B, SCARA5, SLC18A1 and STMN4) located within this region (adjusted P<0.01). Notably, the mRNA levels of PDLIM2, a key regulator of well-known cancer-associated genes including the proto-oncogene c-MYC, an early response gene IER3, and regulators of apoptosis such as BCL2, FAS, and FASLG, were highly downregulated in tumors compared to normal tissues. Conclusion: Taken together, our findings uncovered various genomic alterations potentially leading to metastasis in CRC and provide important insights into the development of potential therapeutic targets for preventing metastatic progression of CRC.