When a collective outcome triggers a rare individual event: a mode of metastatic process in a cell population

A model of early metastatic process is based on the role of the protein PAI-1, which at high enough extracellular concentration promotes the transition of cancer cells to a state prone to migration. This transition is described at the single cell level as a bi-stable switch associated with a subcritical bifurcation. In a multilevel reaction-diffusion scenario, the microenvironment of the tumor is modified by the proliferating cell population so as to push the concentration of PAI-1 above the bifurcation threshold. The formulation in terms of partial differential equations fails to capture spatio-temporal heterogeneity. Cellular-automata and agent-based simulations of cell populations support the hypothesis that a randomly localized accumulation of PAI-1 can arise and trigger the escape of a few isolated cells. Far away from the primary tumor, these cells experience a reverse transition back to a proliferative state and could generate a secondary tumor. The proposed role of PAI-1 in controlling this metastatic cycle is candidate to explain its role in the progression of cancer

A randomized trial comparing adjuvant chemotherapy with gemcitabine plus cisplatin with docetaxel plus cisplatin in patients with completely resected non-small-cell lung cancer with quality of life as the primary objective

International audienceOBJECTIVES: Adjuvant chemotherapy with vinorelbine plus cisplatin (VC) improves survival in resected non-small-cell lung cancer (NSCLC), but has negative impact on quality of life (QoL). In advanced NSCLC, gemcitabine plus cisplatin (GC) and docetaxel plus cisplatin (DC) exhibit comparable efficacy, with possibly superior QoL compared to VC. This trial investigated these regimens in the adjuvant setting. METHODS: Patients with Stage IB to III NSCLC were eligible following standardized surgery. Overall, 136 patients were included, with 67 and 69 assigned to the GC and DC arms, respectively. Cisplatin (75 mg/m(2), Day [D] 1) plus gemcitabine (1250 mg/m(2), D1 and D8) or docetaxel (75 mg/m(2) D1) were administered for three cycles. Primary end-point was QoL (EORTC QLQ-C30), with the study designed to detect a 10-point difference between arms. Overall survival, safety and cost were secondary end-points. RESULTS: No between-group imbalance was observed in terms of patient characteristics. At inclusion, global health status (GHS) scores (/100) were 63.5 and 62.7 in GC and DC, respectively (P = 0.8), improving to 64.5 and 65.4 after 3 months (P = 0.8). No significant difference in functional or symptoms scores was observed between the arms except for alopecia. Grade 3/4 haematological and non-haematological toxicities were found in 33.8 and 21.7% (P = 0.11), and 33.8 and 26.1% (P = 0.33) of patients, in GC and DC, respectively. At 2 years, 92.9 and 89.8% of patients remained alive in GC and DC, respectively (P = 0.88). CONCLUSIONS: DC and GC adjuvant chemotherapies for completely resected NSCLC were well tolerated and appear free of major QoL effects, and are therefore representing candidates for comparison with the standard VC regimen

Genome wide SNP comparative analysis between EGFR and KRAS mutated NSCLC and characterization of two models of oncogenic cooperation in non-small cell lung carcinoma

<p>Abstract</p> <p>Background</p> <p>Lung cancer with EGFR mutation was shown to be a specific clinical entity. In order to better understand the biology behind this disease we used a genome wide characterization of loss of heterozygosity and amplification by Single Nucleotide Polymorphism (SNP) Array analysis to point out chromosome segments linked to <it>EGFR </it>mutations. To do so, we compared genetic profiles between <it>EGFR </it>mutated adenocarcinomas (ADC) and <it>KRAS </it>mutated ADC from 24 women with localized lung cancer.</p> <p>Results</p> <p>Patterns of alterations were different between <it>EGFR </it>and <it>KRAS </it>mutated tumors and specific chromosomes alterations were linked to the <it>EGFR </it>mutated group. Indeed chromosome regions 14q21.3 (p = 0.027), 7p21.3-p21.2 (p = 0.032), 7p21.3 (p = 0.042) and 7p21.2-7p15.3 (p = 0.043) were found significantly amplified in EGFR mutated tumors. Within those regions 3 genes are of special interest <it>ITGB8</it>, <it>HDAC9 </it>and <it>TWIST1</it>. Moreover, homozygous deletions at <it>CDKN2A </it>and LOH at <it>RB1 </it>were identified in <it>EGFR </it>mutated tumors. We therefore tested the existence of a link between EGFR mutation, CDKN2A homozygous deletion and cyclin amplification in a larger series of tumors. Indeed, in a series of non-small-cell lung carcinoma (n = 98) we showed that homozygous deletions at <it>CDKN2A </it>were linked to <it>EGFR </it>mutations and absence of smoking whereas cyclin amplifications (<it>CCNE1 </it>and <it>CCND1</it>) were associated to <it>TP53 </it>mutations and smoking habit.</p> <p>Conclusion</p> <p>All together, our results show that genome wide patterns of alteration differ between <it>EGFR </it>and <it>KRAS </it>mutated lung ADC, describe two models of oncogenic cooperation involving either <it>EGFR </it>mutation and <it>CDKN2A </it>deletion or cyclin amplification and <it>TP53 </it>inactivating mutations and identified new chromosome regions at 7p and 14q associated to EGFR mutations in lung cancer.</p

Meta-analysis of archived DNA microarrays identifies genes regulated by hypoxia and involved in a metastatic phenotype in cancer cells

<p>Abstract</p> <p>Background</p> <p>Metastasis is a major cancer-related cause of death. Recent studies have described metastasis pathways. However, the exact contribution of each pathway remains unclear. Another key feature of a tumor is the presence of hypoxic areas caused by a lack of oxygen at the center of the tumor. Hypoxia leads to the expression of pro-metastatic genes as well as the repression of anti-metastatic genes. As many Affymetrix datasets about metastasis and hypoxia are publicly available and not fully exploited, this study proposes to re-analyze these datasets to extract new information about the metastatic phenotype induced by hypoxia in different cancer cell lines.</p> <p>Methods</p> <p>Affymetrix datasets about metastasis and/or hypoxia were downloaded from GEO and ArrayExpress. AffyProbeMiner and GCRMA packages were used for pre-processing and the Window Welch <it>t </it>test was used for processing. Three approaches of meta-analysis were eventually used for the selection of genes of interest.</p> <p>Results</p> <p>Three complementary approaches were used, that eventually selected 183 genes of interest. Out of these 183 genes, 99, among which the well known <it>JUNB</it>, <it>FOS </it>and <it>TP63</it>, have already been described in the literature to be involved in cancer. Moreover, 39 genes of those, such as <it>SERPINE1 </it>and <it>MMP7</it>, are known to regulate metastasis. Twenty-one genes including <it>VEGFA </it>and <it>ID2 </it>have also been described to be involved in the response to hypoxia. Lastly, DAVID classified those 183 genes in 24 different pathways, among which 8 are directly related to cancer while 5 others are related to proliferation and cell motility. A negative control composed of 183 random genes failed to provide such results. Interestingly, 6 pathways retrieved by DAVID with the 183 genes of interest concern pathogen recognition and phagocytosis.</p> <p>Conclusion</p> <p>The proposed methodology was able to find genes actually known to be involved in cancer, metastasis and hypoxia and, thus, we propose that the other genes selected based on the same methodology are of prime interest in the metastatic phenotype induced by hypoxia.</p

PAI-1 and functional blockade of SNAI1 in breast cancer cell migration

12 pages, 5 figures.-- PMID: 19055748 [PubMed].-- et al.[Introduction]: Snail, a family of transcriptional repressors implicated in cell movement, has been correlated with tumour invasion. The Plasminogen Activation (PA) system, including urokinase plasminogen activator (uPA), its receptor and its inhibitor, plasminogen activator inhibitor type 1(PAI-1), also plays a key role in cancer invasion and metastasis, either through proteolytic degradation or by non-proteolytic modulation of cell adhesion and migration. Thus, Snail and the PA system are both over-expressed in cancer and influence this process. In this study we aimed to determine if the activity of SNAI1 (a member of the Snail family) is correlated with expression of the PA system components and how this correlation can influence tumoural cell migration.[Methods]: We compared the invasive breast cancer cell-line MDA-MB-231 expressing SNAI1 (MDA-mock) with its derived clone expressing a dominant-negative form of SNAI1 (SNAI1-DN). Expression of PA system mRNAs was analysed by cDNA microarrays and real-time quantitative RT-PCR. Wound healing assays were used to determine cell migration. PAI-1 distribution was assessed by immunostaining.[Results]: We demonstrated by both cDNA microarrays and realtime quantitative RT-PCR that the functional blockade of SNAI1 induces a significant decrease of PAI-1 and uPA transcripts. After performing an in vitro wound-healing assay, we observed that SNAI1-DN cells migrate more slowly than MDA-mock cells and in a more collective manner. The blockade of SNAI1 activity resulted in the redistribution of PAI-1 in SNAI1-DN cells decorating large lamellipodia, which are commonly found structures in these cells.[Conclusions]: In the absence of functional SNAI1, the expression of PAI-1 transcripts is decreased, although the protein is redistributed at the leading edge of migrating cells in a manner comparable with that seen in normal epithelial cells.This work was supported by the CNRS ACI Program "Complexité du vivant" (grant # 050009DR11) and by the Evry Genopole grant "Aide à l'acquisition d'équipement semi-lourd" 2007 and 2008.Peer reviewe

Peripheral primitive neuroectodermal tumor of the cauda equina in an elderly patient. Case report.

International audiencePrimitive neuroectodermal tumors (PNETs) are aggressive neoplasms composed predominantly of undifferentiated cells that show evidence of neural differentiation. Although their classification remains disputed, PNETs are recognized as primary tumors in both the central and peripheral nervous systems. These rare tumors usually occur in children or young adults and are typically metastatic to the spinal cord. The authors report the case of a 70-year-old man with no significant medical history, in whom a peripheral PNET was demonstrated that, based on clinical and imaging findings, manifested as a nonspecific intrathecal tumoral process arising from the cauda equina. Although this lesion is rare in the elderly, the authors' case illustrates the importance of making this diagnosis as early as possible so that a treatment plan may be devised. The use of chemotherapy in association with radiotherapy in relation to the resection of the tumor should be reconsidered

Progresses in the medical treatment of advanced colorectal cancer

International audienceIn the last 2 decades, major progresses have been made in the management of patients with advanced colorectal cancer (ACC). The modulation of 5-fluorouracil (5-FU) by folinic acid (LV), followed by the introduction of irinotecan and oxaliplatin have significantly improved the outcome of these patients. New strategies consist of oral fluoropyrimidines, and of targeted agents to inhibit cancer signalisation