The cytidine analogues azacytidine and 5-aza-2'-deoxycytidine (decitabine) are commonly used to treat myelodysplastic syndromes, with or without a myeloproliferative component. It remains unclear whether the response to these hypomethylating agents results from a cytotoxic or an epigenetic effect. In this study, we address this question in chronic myelomonocytic leukaemia. We describe a comprehensive analysis of the mutational landscape of these tumours, combining whole-exome and whole-genome sequencing. We identify an average of 14±5 somatic mutations in coding sequences of sorted monocyte DNA and the signatures of three mutational processes. Serial sequencing demonstrates that the response to hypomethylating agents is associated with changes in DNA methylation and gene expression, without any decrease in the mutation allele burden, nor prevention of new genetic alteration occurence. Our findings indicate that cytosine analogues restore a balanced haematopoiesis without decreasing the size of the mutated clone, arguing for a predominantly epigenetic effect.

The differentiation-related gene-1 (Drg-1) was first identified as a gene strongly upregulated by induction of differentiation in colon carcinoma cells in vitro, and later the same gene was shown to suppress tumorigenicity of human bladder cancer cells in vivo. On the other hand, we and others have demonstrated that the Drg-1 gene suppresses prostate and colon cancer metastases in mouse models. In the context of such potential organ-specific differential function of the Drg-1 gene, the present study was designed to clarify the expression status, regulation and function of Drg-1 in the case of human breast cancer. We found that the expression of the Drg-1 protein was significantly reduced in breast tumor cells, particularly in patients with lymph node or bone metastasis as compared to those with localized breast cancer. Drg-1 expression also exhibited significant inverse correlation with the disease-free survival rate of patients and emerged as an independent prognostic factor. The downregulation of the Drg-1 gene appeared to be largely at the RNA level, and the DNA methylation inhibitor, 5-Azacytidine, significantly elevated the Drg-1 gene expression in various breast tumor cell lines. Furthermore, we found that overexpression of the Drg-1 gene suppresses the invasiveness of breast cancer cells in vitro, and this suppression was also achieved by treatment of cells with 5-Azacytidine. Together, our results strongly suggest functional involvement of the Drg-1 gene in suppressing the metastatic advancement of human breast cancer.

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The highly proliferating C2A subtype is characterized by topoisomerase 2-alpha gene up-regulation and FA pathway activation, and the HB therapeutic arsenal could include bortezomib for the treatment of patients with the most aggressive tumors. (Hepatology 2018;68:89-102).

Using a differential display method to identify differentiation-related genes in human myelomonocytic U937 cells, we cloned the cDNA of a gene identical to Drg1 and homologous to other recently discovered genes, respectively human RTP and Cap43 and mouse Ndr1 and TDD5 genes. Their open reading frames encode proteins highly conserved between mouse and man but which do not share homology with other know proteins. Conditions in which mRNAs are up-regulated suggest a role for the protein in cell growth arrest and terminal differentiation. We raised antibodies against a synthetic peptide reproducing a characteristic sequence of the putative polypeptide chain. These antibodies revealed a protein with the expected 43 kDa molecular mass, up-regulated by phorbol ester, retinoids and 1,25-(OH)2 vitamin D3 in U937 cells. It was increased in mammary carcinoma MCF-7 cells treated by retinoids and by the anti-estrogen ICI 182,780 but not by 4-hydroxytamoxifen. The mouse Drg1 homologous protein was up-regulated by retinoic acid in C2 myogenic cells. The diversity of situations in which expression of RTP/Drg1/Ndr1 has now been observed shows that it is widely distributed and up-regulated by various agents. Here we show that ligands of nuclear transcription factors involved in cell differentiation are among the inducers of this novel protein.

The tumor metastasis suppressor gene Drg-1 has been shown to suppress metastasis without affecting tumorigenicity in immunodeficient mouse models of prostate and colon cancer. Expression of Drg-1 has also been found to have a significant inverse correlation with metastasis or invasiveness in various types of human cancer. However, how Drg-1 exerts its metastasis suppressor function remains unknown. In the present study, to elucidate the mechanism of action of the Drg-1 gene, we did a microarray analysis and found that induction of Drg-1 significantly inhibited the expression of activating transcription factor (ATF) 3, a member of the ATF/ cyclic AMP-responsive element binding protein family of transcription factors. We also showed that Drg-1 attenuated the endogenous level of ATF3 mRNA and protein in prostate cancer cells, whereas Drg-1 small interfering RNA upregulated the ATF3 expression. Furthermore, Drg-1 suppressed the promoter activity of the ATF3 gene, indicating that Drg-1 regulates ATF3 expression at the transcriptional level. Our immunohistochemical analysis on prostate cancer specimens revealed that nuclear expression of ATF3 was inversely correlated to Drg-1 expression and positively correlated to metastases. Consistently, we have found that ATF3 overexpression promoted invasiveness of prostate tumor cells in vitro, whereas Drg-1 suppressed the invasive ability of these cells. More importantly, overexpression of ATF3 in prostate cancer cells significantly enhanced spontaneous lung metastasis of these cells without affecting primary tumorigenicity in a severe combined immunodeficient mouse model. Taken together, our results strongly suggest that Drg-1 suppresses metastasis of prostate tumor cells, at least in part, by inhibiting the invasive ability of the cells via downregulation of the expression of the ATF3 gene. (Cancer Res 2006; 66(24): 11983-90)

Interleukin-6 plays a central role in normal B-cell maturation and in proliferation of some B-cell malignancies including multiple myeloma and some non Hodgkin's lymphomas (NHL). Furthermore, this cytokine also plays a major role in acute phase response by mediating synthesis of acute phase proteins such as C-reactive protein (CRP). In order to evaluate the exact role of CRP serum level as a simple prognostic factor, we analyzed CRP and IL-6 serum levels in 39 patients with NHL. Eleven patients had low grade NHL, 15 intermediate grade NHL, and 13 high grade NHL. Thirty percent of the patients presented detectable IL-6 serum levels (mean+/-SD: 33.6+/-95.2 U/ml, range: 0 to 500). Increased serum CRP levels were found in 42% of the patients with a mean of 29.2+/-41.97 mg/l] (range: 0 to 129). Thirty seven patients were studied for both markers. Three groups of patients were determined. One with low IL-6 and CRP serum levels (N=21), a second with high level of both markers (N=10), and the third with high serum CRP levels alone (N = 5). Only one patient had high level of serum IL-6 with no detectable CRP. The correlation of serum IL-6 and CRP levels with patient survival was investigated. Median survival in the group with low IL-6 level was not reached. 67% of patients of this group were still alive at 32 months from diagnosis. The group of patients with detectable IL-6 had a median of survival of 12 months (p<0.025). The survival of patients with a CRP<10 mg/l was not reached. 75% of patients survive at 32 months from diagnosis, whereas the group with higher CRP level reached a median survival at 8.5 months (p<0.009). As expected, on univariate analysis, there is a significant relationship between CRP and IL-6 levels (p<0.00017), and CRP levels and B symptoms (p<0.001). Furthermore there is a significant relationship between CRP and LDH levels (p<0.042).These results indicated that CRP may be considered as a valuable and easy prognostic biomarker of NHL.

Large-scale identification of genes expressed in roots of the model plant Arabidopsis was performed by serial analysis of gene expression (SAGE), on a total of 144,083 sequenced tags, representing at least 15,964 different mRNAs. For tag to gene assignment, we developed a computational approach based on 26,620 genes annotated from the complete sequence of the genome. The procedure selected warrants the identification of the genes corresponding to the majority of the tags found experimentally, with a high level of reliability, and provides a reference database for SAGE studies in Arabidopsis. This new resource allowed us to characterize the expression of more than 3,000 genes, for which there is no expressed sequence tag (EST) or cDNA in the databases. Moreover, 85% of the tags were specific for one gene. To illustrate this advantage of SAGE for functional genomics, we show that our data allow an unambiguous analysis of most of the individual genes belonging to 12 different ion transporter multigene families. These results indicate that, compared with EST-based tag to gene assignment, the use of the annotated genome sequence greatly improves gene identification in SAGE studies. However, more than 6,000 different tags remained with no gene match, suggesting that a significant proportion of transcripts present in the roots originate from yet unknown or wrongly annotated genes. The root transcriptome characterized in this study markedly differs from those obtained in other organs, and provides a unique resource for investigating the functional specificities of the root system. As an example of the use of SAGE for transcript profiling in Arabidopsis, we report here the identification of 270 genes differentially expressed between roots of plants grown either with NO 3 Ϫ or NH 4 NO 3 as N source.