c-Myc controls more than 15% of genes responsible for proliferation, differentiation, and cellular metabolism in pancreatic as well as other cancers making this transcription factor a prime target for treating patients. The transcriptome of 55 patient derived xenografts show that 30% of them share an exacerbated expression profile of MYC transcriptional targets (MYC-high). This cohort is characterized by a high level of Ki67 staining, a lower differentiation state and a shorter survival time compared to the MYC-low subgroup. To define classifier expression signature, we selected a group of 10 MYC targets transcripts which expression is increased in the MYC-high group and 6 transcripts increased in the MYC-low group. We validated the ability of these markers panel to identify MYC-high patient-derived xenografts from both: discovery and validation cohorts as well as primary cells cultures from the same patients. We then showed that cells from MYC-high patients are more sensitive to JQ1 treatment compared to MYC-low cells, in both monolayer and 3D cultured spheroids, due to cell cycle arrest followed by apoptosis. Therefore, these results provide new markers and potentially novel therapeutic modalities for distinct subgroups of pancreatic tumors and may find application to the future management of these patients within the setting of individualized medicine clinics.
Gene expression profiling of patient-derived pancreatic cancer xenografts predicts sensitivity to the BET bromodomain inhibitor JQ1: implications for individualized medicine efforts.
Disease
View SamplesA major impediment to the effective treatment of patients with PDAC (Pancreatic Ductal Adenocarcinoma) is the molecular heterogeneity of the disease, which is reflected in an equally diverse pattern of clinical responses to therapy. We developed an efficient strategy in which PDAC samples from 17 consecutively patients were obtained by EUS-FNA or surgery, their cells maintained as a primary culture and tumors as breathing tumors by xenografting in immunosuppressed mice. For these patients a clinical follow up was obtained. On the breathing tumors we studied the RNA expression profile by an Affymetrix approach. We observed a significant heterogeneity in their RNA expression profile, however, the transcriptome was able to discriminate patients with long- or short-time survival which correspond to moderately- or poorly-differentiated PDAC tumors respectively. Cells allowed us the possibility to analyze their relative sensitivity to several anticancer drugs in vitro by developing a chimiogram, like an antibiogram for microorganisms, with several anticancer drugs for obtaining an individual profile of drug sensitivity and as expected, the response was patient-dependent. Interestingly, using this approach, we also found that the transcriptome analysis could predict the sensitivity to some anticancer drugs of patients with a PDAC. In conclusion, using this approach, we found that the transcriptome analysis could predict the sensitivity to some anticancer drugs and the clinical outcome of patients with a PDAC.
Transcriptomic analysis predicts survival and sensitivity to anticancer drugs of patients with a pancreatic adenocarcinoma.
Sex, Age, Specimen part
View SamplesCancer cachexia syndrome is observed in 80% of patients with advanced-stage cancer, and it is one of the most frequent causes of death. Severe wasting accounts for more than 80% in patients with advanced pancreatic cancer. Here we wanted to define, by using an microarray approach and the Pdx1-cre;LSL-KrasG12D;INK4a/arffl/fl, the pathways involved in muscle, liver and white adipose tissue wasting.
Pancreatic cancer-induced cachexia is Jak2-dependent in mice.
Age, Specimen part, Disease, Disease stage
View SamplesStudy question: Can region-specific transcriptional profiling of the epididymis from fertile and sub-fertile bulls predict the aetiology of fertility/subfertility in males? Summary answer:The highly regulated gene expression along the bovine epididymis is affected by the fertility status of bulls used for artificial insemination. What is known already: In mammals, sperm maturation and storage occur in the epididymis. Each epididymal segment has his own transcriptomic signature that modulates the intraluminal composition that governs sequential modifications of the maturing male gamete. Main results and the role of chance: Hierarchical clustering and Principal Component Analysis revealed a clear separation between caput, corpus and cauda epididymides. Some transcripts characterize a particular anatomical segment, whereas others are expressed in two out of three epididymal segments. GO analysis allowed deduction of specific functions played by each epididymal segment. The transcriptional profiles between fertile vs. sub-fertile conditions clustered most closely in the corpus and cauda segments, whereas the profiles in the caput segment were distinct between fertile and sub-fertile bulls. Of the differently expressed genes, ten (including AKAP4, SMCP, SPATA3, TCP11, ODF1, CTCFL, SPATA18, ADAM28, SORD and FAM161A) were found to exert functions related to reproductive systems and 5 genes (including DEAD, CYST11, DEFB119, DEFB124 and MX1) were found to be associated with the defence response. Limitations, reasons for caution: Further work is required to correlate these modulations of epididymal functions with sperm fertilizing ability in order to understand the aetiology of certain cases of idiopathic infertility in livestock and men. Wider implications of the findings: As fertility can be quantified in bulls used for artificial insemination, this species is a unique model to aid in the understanding of male fertility/subfertility in man.Our data provide a molecular characterization that will facilitate advances in understanding the involvement of epididymalphysiology in sub/infertility aetiology.
No associated publication
Specimen part
View SamplesWallerian degeneration (WD) involves the fragmentation of axonal segments disconnected from their cell bodies, segmentation of the myelin sheath, and removal of debris by Schwann cells and immune cells. The removal and downregulation of myelin-associated inhibitors of axonal regeneration and synthesis of growth factors by these two cell types are critical responses to successful nerve repair. Here, we analyzed the transcriptome of the sciatic nerve of mice carrying the Wallerian degeneration slow (WldS) mutant gene, a gene that confers axonal protection in the distal stump after injury, therefore causing significant delays in WD, neuroinflammation, and axonal regeneration.
No associated publication
Specimen part, Time
View SamplesAndrogens have been postulated to be important modulators of adipose tissue metabolism and fat cell function. In the present study, we investigated the response of male and female mice retroperitoneal adipose tissue to the non-aromatizable androgen dihydrotestosterone (DHT). Adipose tissue samples were obtained in gonadectomized (GDX) animals treated with vehicle (control group), or injected with 0.1mg DHT at 1, 3, 6, 12, 18 and 24h prior to necropsy. Transcripts which were significantly modulated were considered as androgen-responsive genes. Quantitative real-time RT-PCR was used to confirm results from the microarry analysis in a subset of 46 probe sets in male mice and 98 probe sets in female mice. Using both methods and considering peak time versus control, 74.5% and 61.2% of the modulated genes were confirmed by PCR in males and females, respectively. Four genes were significantly stimulated in a similar manner by DHT in both sexes, namely metallothionein 1 (Mt1), growth arrest and DNA-damage-inducible 45 gamma (Gadd45g), cyclin-dependent kinase inhibitor 1A (Cdkn1a), and fk506-binding protein 5 (Fkbp5). All these genes appear to be associated with a down-regulation of adipocyte differentiation/proliferation and adipogenesis. In conclusion, this study which evaluated the transcriptome response of adipose tissue to DHT in male and female mice suggests that DHT consistently modulates genes involved in the regulation of adipogenesis in retroperitoneal adipose tissue of both male and female animals.
Response of the adipose tissue transcriptome to dihydrotestosterone in mice.
No sample metadata fields
View SamplesThe efficacy and exceptionally good tolerance of estrogen blockade in the treatment of breast cancer is well recognized but novel agents are required, especially to take advantage of the multiple consecutive responses obtained in breast cancer progressing following previous hormone therapy, thus delaying the use of cytotoxic chemotherapy with its usually serious side effects. Acolbifene (ACOL) is a novel and unique antiestrogen completely free of estrogen-like activity in both the mammary gland and uterus while preventing bone loss. From the preclinical and clinical data so-far available, this new antiestrogen represents a unique opportunity for a highly potent and specific blockade of estrogen action in the mammary gland and uterus while exerting estrogen-like beneficial effects in other tissues (selective estrogen receptor modulator or SERM activity). In order to better understand the specificity of action of acolbifene, we have used Affymetrix GeneChips containing 45,000 probe sets to analyze 34,000 genes to determine the specificity of this compound compared to the pure antiestrogen fulvestrant, as well as the mixed antagonists/agonists tamoxifen and raloxifene to block the effect of estradiol (E2) and to induce effects of their own on gene expression in the mouse mammary gland. The genes modulated by E2 were those identified in two separate experiments and validated by quantitative real-time PCR (Q_RT-PCR). Three hours after the single subcutaneous injection of E2 (0.05 ug), the simultaneous administration of acolbifene, fulvestrant, tamoxifen and raloxifene blocked by 98%, 62%, 43% and 92% the number of E2-upregulated genes, respectively. On the other hand, 70%, 10%, 25% and 55% of the genes down-regulated by E2 were blocked by the same compounds. Acolbifene was also the compound which, when used alone, modulated the smallest number of genes also influenced by E2, namely 4%, thus possibly explaining the potent tumoricidal action of this compound in human breast cancer xenografts where 61% of tumors disappeared, thus bringing a new paradigm in the hormonal therapy of breast cancer.
Specific transcriptional response of four blockers of estrogen receptors on estradiol-modulated genes in the mouse mammary gland.
Specimen part, Treatment
View SamplesFat intake is an important determinant in the development of obesity. The small intestine is the principal site of digestion and absorption of nutrients, and these short-term circulating nutrients and hormones as well as neural signals derived from the peripheral tissues in responses to a meal act at multiple central nervous system sites where food intake is controlled.
Identification of the principal transcriptional regulators for low-fat and high-fat meal responsive genes in small intestine.
Sex, Specimen part
View SamplesThe objective of this study was to elucidate the role of Nupr1 in pancreatic tumorigenesis. Using the Pdx-1-cre;LSL-KrasG12D mouse as model we discovered that, in contrast to KrasG12D pancreas that develop multiple foci of pancreatic intraepithelial neoplasia (PanIN), KrasG12D;Nupr1KO pancreas were free from such lesions, indicating that Nupr1 is pivotal for PanIN formation. In vitro, MiaPaCa2 cells activated Nupr1 expression in response to nutrient deprivation and this expression was necessary for cell survival. Mechanistically, Nupr1 protected cells from stress-induced death by inhibiting apoptosis through an alternative RelBIER3-dependent pathway and independent from activation of the classical RelA-based NF-kB pathway. In agreement with these findings, Nupr1, RelB and IER3 proteins were found co-expressed in PanINs from KrasG12D pancreas. Moreover, pancreas-specific KrasG12D;RelbDpanc mice displayed a delay in PanIN development associated with a lack of IER3 expression, further emphasizing the relevance of this pathway in vivo. Efficient PanIN formation was therefore dependent on the expression of Nupr1 and RelB, with the probable involvement of IER3. Finally, a significant correlation between expression of Nupr1, RelB and IER3 and a poor prognosis of patients with PDAC was found. Altogether, our results reveal a novel stress-related pathway that requires the functional interaction of Nupr1RelBIER3 in KrasG12D-dependent transformation of the pancreas and expand our understanding of the molecular machinery that mediates the early steps of pancreatic carcinogenesis.
No associated publication
Cell line
View SamplesDicer1 is an endoribonuclease involved in the biogenesis of functional microRNAs (miRNAs). These small non-coding RNAs are important regulators of the posttranscriptional gene expression and participate to the control of male fertility. Knowing that 1) Dicer1-dependent factors are needed for proper sperm maturation in the epididymis, and that 2) miRNAs are potent mediators of intercellular communication in most biological systems, we investigated the role of Dicer1 dependent-miRNAs produced from the proximal epididymis (initial segment/caput) on the paracrine regulation of epididymal gene expression in the distal epididymis regions (i.e. corpus and cauda). To this aim, we performed comparative microarray and ANOVA analyses on control vs. Defb41iCre/wt;Dicer1fl/fl mice in which functional Dicer1 is absent from the principal cells of the proximal epididymis. We identified 21 and 16 transcripts, including Prostate And Testis Expressed 4 protein and the Zn-alpha 2-glycoprotein, that display significant expression level changes in the corpus and cauda regions, respectively (Fold change >2 or <-2; p<0.001). In addition, 154 miRNAs, including miR- 210, miR-672, miR-191 and miR-204, show a significantly impaired biogenesis in the absence of Dicer1 from the proximal epididymis (Fold change>2 or <-2; p<0.01). These miRNAs are secreted via extracellular vesicles derived from DC2 epididymal principal cell line, and their expression correlates with target transcripts involved in important biological pathways, as evidenced by in silico analysis. These observations suggest that Dicer1-dependent miRNAs could act as potent paracrine regulators of epididymal functions (i.e. control of sperm motility, ciliogenesis) and may contribute to the infertility phenotype observed in the Defb41iCre/wt;Dicer1fl/fl mouse model. These findings open new avenues for the identification of molecular targets important to male fertility control.
No associated publication
Specimen part
View Samples