Effects of plant extracts on gene expression profiling: from macrorrays to microarray technology

Lead Molecules from Natural Products: Discovery and New Trends provides the reader with a thorough overview of current discoveries and trends in Natural Products research. This book consists of 22 chapters from well known scientists all over the world, with topics ranging from Natural Product Chemistry and Phytochemistry in their most basic form, to Molecular Biology and in silico drug design. Contributors describe their own laboratory experiences, revealing their findings, the legal issues encountered. The chapters, all of equally high quality, summarize years of extensive research in each area, and provide insight in the new themes of natural product research. The information will help to predict promising leads, useful for physicians in the treatment of different diseases and disease manifestations

VAV PROMOTES DIFFERENTIATION OF HUMAN TUMORAL MYELOID PRECURSORS

Vav is one of the genetic markers that correlate with the differentiation of hematopoietic cells. In T and B cells, it appears crucial for both development and functions, while, in non-lymphoid hematopoietic cells, Vav seems not involved in cell maturation, but rather in the response of mature cells to agonist-dependent proliferation and phagocytosis. We have previously demonstrated that the amount and the tyrosine phosphorylation of Vav are up-regulated in both whole cells and nuclei of tumoral promyelocytes induced to granulocytic maturation by ATRA and that tyrosine-phosphorylated Vav does not display any ATRA-induced GEF activity but contributes to the regulation of PI 3-K activity. In this study, we report that Vav accumulates in nuclei of ATRA-treated APL-derived cells and that the down-modulation of Vav prevents differentiation of tumoral promyelocytes, indicating that it is a key molecule in ATRA-dependent myeloid maturation. On the other hand, the overexpression of Vav induces an increased expression of surface markers of granulocytic differentiation without affecting the maturation-related changes of the nuclear morphology. Consistent with an effect of Vav on the transcriptional machinery, array profiling shows that the inhibition of the Syk-dependent tyrosine phosphorylation of Vav reduces the number of ATRA-induced genes. Our data support the unprecedented notion that Vav plays crucial functions in the maturation process of myeloid cells, and suggest that Vav can be regarded as a potential target for the therapeutic treatment of myeloproliferative disorders

CDNA-array profiling of melanomas and paired melanocyte cultures

Three paired (from the same donor) sets of melanoma cells and normal melanocytes, established as early-passage cultures from metastatic lesions and the uninvolved skin of three patients, were comparatively cDNA profiled by macroarrays (approximately 1,200 genes) and reverse transcription (RT)-PCR. While 145 gene products were significantly (at least twofold) upregulated or downregulated in at least 1 pair, and 23 were in at least 2 pairs, only 3 (the signal transducer and activator of transcription STAT2, collagen type VI, and CD9) were concordantly modulated (downregulation) in all 3 pairs. Array results were validated by RT-PCR on a small panel of surgically removed nevocellular nevi and metastatic melanoma lesions, and by immunohistochemistry on a large panel of benign and malignant lesions of the nevomelanocytic lineage. The three gene products were downregulated at different stages of melanoma progression. STAT2 was detectable in nevi (5/5) and most primary melanomas (11/12), but was lost in 10/15 metastatic lesions. Collagen type VI was expressed in nevi (5/5) and primary melanomas below a Breslow thickness of 1 mm (3/3), but was lost in 24/24 primary melanomas above this threshold, and in metastatic melanomas (10/10). The tetraspanin CD9 molecule was expressed in 18/18 nevi, but was lost in 20/28 primary melanomas (including thin lesions), and in 24/52 metastatic lesions. These data provide the proof of principle that cDNA profiling of paired melanocyte/melanoma Cultures sorts out novel, early signatures of melanocyte transformation that could contribute to the clinical management of patients at high risk of metastatic disease

cDNA-array profiling of melanomas and paired melanocyte cultures.

Three paired (from the same donor) sets of melanoma cells and normal melanocytes, established as early-passage cultures from metastatic lesions and the uninvolved skin of three patients, were comparatively cDNA profiled by macroarrays (approximately 1,200 genes) and reverse transcription (RT)-PCR. While 145 gene products were significantly (at least twofold) upregulated or downregulated in at least 1 pair, and 23 were in at least 2 pairs, only 3 (the signal transducer and activator of transcription STAT2, collagen type VI, and CD9) were concordantly modulated (downregulation) in all 3 pairs. Array results were validated by RT-PCR on a small panel of surgically removed nevocellular nevi and metastatic melanoma lesions, and by immunohistochemistry on a large panel of benign and malignant lesions of the nevomelanocytic lineage. The three gene products were downregulated at different stages of melanoma progression. STAT2 was detectable in nevi (5/5) and most primary melanomas (11/12), but was lost in 10/15 metastatic lesions. Collagen type VI was expressed in nevi (5/5) and primary melanomas below a Breslow thickness of 1 mm (3/3), but was lost in 24/24 primary melanomas above this threshold, and in metastatic melanomas (10/10). The tetraspanin CD9 molecule was expressed in 18/18 nevi, but was lost in 20/28 primary melanomas (including thin lesions), and in 24/52 metastatic lesions. These data provide the proof of principle that cDNA profiling of paired melanocyte/melanoma cultures sorts out novel, early signatures of melanocyte transformation that could contribute to the clinical management of patients at high risk of metastatic disease

Connections Between Genetics and Clinical Data: Role of MCP-1, CFTR, and SPINK-1 in the Setting of Acute, Acute Recurrent, and Chronic Pancreatitis

OBJECTIVES: Acute, acute recurrent, and chronic pancreatitis are inflammatory diseases with multifactorial pathogenic mechanisms. Genetic mutations and polymorphisms have been correlated with pancreatitis. The aim of this study was to investigate the association of cystic fibrosis transmembrane conductance regulator (CFTR) and serine protease inhibitor Kazal type 1 (SPINK-1) gene mutations and monocyte chemoattractant protein 1 (MCP-1) -2518A/G polymorphism with acute pancreatitis (AP), acute recurrent pancreatitis (ARP), and chronic pancreatitis (CP), and to associate genetic backgrounds with clinical phenotype in these three conditions.METHODS: One hundred eighteen AP, 64 ARP, 142 CP patients, and 88 normal controls were enrolled consecutively. We analyzed MCP-1 serum levels using enzyme-linked immunosorbent assay. Polymorphism -2518 of MCP-1 and SPINK-1 N34S gene mutations were determined by PCR-restriction-fragment length polymorphism. Sequence analysis was performed when necessary. Thirty-three CFTR mutations were analyzed in CP and ARP patients using multiplex DNA testing.RESULTS: Serum MCP-1 levels were significantly higher in all patients affected by pancreatic inflammatory diseases. Moreover, we found a significant over-representation of the MCP-1G allele in ARP patients. We found a statistically significant association of CFTR gene mutations with ARP, but not with CP. We did not find a statistically significant association of ARP or CP with the N34S SPINK-1 gene mutation. Interestingly, 39 of 64 ARP patients (61%) carried at least one genetic mutation and/or polymorphism. Five of 64 ARP patients had pancreas divisum and four of these five also carried the G allele.CONCLUSIONS: Analysis of a comprehensive range of potential susceptibility variants is needed to support modeling of the effects of genes and environment in pancreatitis. As such, beyond gene mutations, the context within which those mutations exist must be considered. In pancreatitis the context includes the inflammatory response, clinical features, and exogenous factors