P M Martin

Bio: P M Martin is an academic researcher from Curie Institute. The author has contributed to research in topics: Breast cancer & Plasminogen activator. The author has an hindex of 6, co-authored 14 publications receiving 401 citations.

Frequency and genome load of Epstein-Barr virus in 509 breast cancers from different geographical areas.

Abstract: Since the few data exploring a possible association between Epstein–Barr virus (EBV) and breast cancer are conflicting, we investigated this association together with the influences of geographical areas. 509 breast cancers were sampled from areas with varying risks of nasopharynx carcinoma (NPC) such as North Africa (Algeria and Tunisia, high-risk area); southern France (Marseille, intermediate-risk area); and northern Europe (northern France, the Netherlands and Denmark; low-risk areas). Polymerase chain reaction (PCR) of a subregion of EBV BamHIC encoding the EBERs demonstrated that 31.8% of the tumours contained the viral genome. No significant differences were observed among the geographical areas. However, positive samples showed higher loads of the EBV genome in the NPC high- and intermediate-risk areas than in the low-risk areas. EBV type 1 was the dominant strain. In situ hybridization studies using a35S-labelled riboprobe for EBER1 and a laser capture microdissection, combined with quantitative PCR, showed that EBV localization was restricted to some tumour epithelial cell clusters. EBV could not be detected in the stroma. Considering the whole population covered, the presence of the EBV genome was not correlated with age, menopausal status, tumour, size, nodal status or histological grade. © 2001 Cancer Research Campaign http://www. bjcancer.com

Epstein-Barr virus as a marker of biological aggressiveness in breast cancer

Abstract: A viral aetiology is one recently evocated theory behind the physiopathology of breast cancer (BC) (Glaser et al, 2004; de Villiers et al, 2005; zur Hausen, 2009). Even though, the mechanistic aspects of cancer induction by infectious agents sound multiples, that is, immunosuppressive, linked to animal–human transmission, direct or indirect oncogenic, there are epidemiological evidences of pathogens involvement in human cancer (zur Hausen, 2009). Among the putative viruses observed in BC tissue, the presence of the Epstein-Barr virus (EBV), a γ-herpes virus, has been reported in a number of studies (Bonnet et al, 1999; Fina et al, 2001; Glaser et al, 2004). The implication of EBV in carcinogenesis associated with other cancers, such as Burkitt's lymphoma, undifferentiated nasopharyngeal carcinoma, as well as Hodgkin's disease, has been well documented (zur Hausen, 1991). However, the presence and implication of EBV in BC remains controversial. The use of conventional technical approaches (in situ hybridisation, immunochemistry and standard PCR) for its detection may explain the conflicting results. Some groups have failed to detect EBV (Chang et al, 1992; Gaffey et al, 1993; Lespagnard et al, 1995; Chu et al, 1998; Glaser et al, 1998; Dadmanesh et al, 2001; Deshpande et al, 2002; Herrmann and Niedobitek, 2003; Perrigoue et al, 2005), whereas results from others show discrepancy and depended on the methodology used. For instance, although Murray et al (2003)could detect EBV nuclear antigen-1 by immunochemistry using 2B4-1 monoclonal antibody, they failed to detect the EBV genome by quantitative PCR. The reasons behind these apparently conflicting results remain to be clarified; however, technical limitations of the assays, dissimilarities in the archival materials and heterogeneity among cluster cells contaminated by the EBV genome may be same. Moreover, EBV positivity has been linked to the presence of latently infected lymphocytes in the tumours (Horiuchi et al, 1994; Brink et al, 2000) thus, questioning the role of EBV in BC (Chu et al, 2001). However, in accordance with other groups (Labrecque et al, 1995; Luqmani and Shousha, 1995; Bonnet et al, 1999; Chu et al, 2001; Huang et al, 2003; Preciado et al, 2005; Arbach et al, 2006; Perkins et al, 2006; Tsai et al, 2007), we have shown the presence of EBV genetic information in a subset of BC tissue with a specific localisation in the epithelial malignant cells (Fina et al, 2001). Currently, real-time PCR (RT–PCR is increasingly being used for both research and clinical applications. For BC in particular, the detection of HER2 gene amplification has been validated by comparison with conventional methods, such as FISH (Lamy et al, 2006). Analysis using RT–PCR might also help to clearly identify the presence of EBV in BC. However, the use of whole tissue can result in the risk of contamination and this risk has been corrected with the introduction of laser-assisted microdissection (Fina et al, 2001). In studies on formalin-fixed sections, micro- and macro-dissected breast tumours have been tested for the presence of multiple regions of the EBV genome with few actually uncovering the viral sequence (McCall et al, 2001; Thorne et al, 2005). Interestingly, by in situ hybridisation using a (35)S-labelled riboprobe for Epstein-Barr encoded RNA 1 and a laser capture microdissection on frozen samples, combined with quantitative PCR (Q-PCR), we showed that EBV localisation was restricted to certain tumour epithelial cell clusters (Fina et al, 2001). In accordance with our findings, Arbach et al (2006) observed that viral load is variable between tumours and is heterogeneously distributed among morphologically identical tumour cells, some clusters containing high genome numbers compared with others negative for EBV genome within the same specimen. In the present study, we hypothesised that EBV-infected BC cells might behave differently in comparison to those negative for EBV. In order to test this, we sought to (i) measure the frequency of EBV positivity using RT–PCR and (ii) to compare the biological phenotype of EBV-negative and EBV-positive tumours.

Determination of TGFbeta1 protein level in human primary breast cancers and its relationship with survival.

Abstract: Transforming growth factor-beta (TGFβ)1 is thought to be implicated in breast cancer progression. However, data about the influence of TGFβ1 on breast cancer development are conflicting. To clarify the clinical relevance of TGFβ1, TGFβ1 protein level has been measured by enzyme-immoassay in 193 breast tumour samples. We found that 94.3% of patients expressed TGFβ1 with a range of 0–684 pg mg−1 protein. In the overall population, an increase of tumoral TGFβ1 was observed in premenopausal patients when compared to postmenopausal subgroup (P=0.0006). When patients were subdivided according to nodal status, TGFβ1 was correlated to type-1 plasminogen activator inhibitor in the node-negative subgroup (P=0.040). Multivariate analysis revealed that, after lymph node status (P=0.0002) and urokinase-type plasminogen activator (P=0.004), TGFβ1 was an independent prognostic marker for DFS (P=0.005) in the overall population. In the node-negative population, TGFβ1 was the prominent prognostic factor (P=0.010). In the same population, Kaplan–Meier curves demonstrated that high TGFβ1 level was correlated with a shorter disease-free survival (P=0.020). These data suggest that the measurement of tumoral TGFβ1 protein level, especially for node-negative patients, might help to identify a high-risk population early in tumour progression.

Thymidine Kinase as a Proliferative Marker: Clinical Relevance in 1,692 Primary Breast Cancer Patients

Abstract: PURPOSE: To assess the prognostic value of thymidine kinase (TK), an enzyme involved in the DNA synthesis salvage pathway, relative to other prognostic factors in primary breast cancer. PATIENTS AND METHODS: This retrospective study involved 1,692 patients with operable breast cancer treated in six institutions (median follow-up, 82 months). Among the 857 node-negative patients, 135 received adjuvant chemotherapy (fluorouracil, doxorubicin, cyclophosphamide [FAC] or fluorouracil, etoposide, and cisplatin [FEC]). TK was assayed in cytosol with a quantitative radioenzymatic technique. Disease-specific survival (DSS), local recurrence-free interval (LRI), and distant-relapse-free interval (DRI) were investigated. RESULTS: High TK levels were associated with large tumor size, high histologic grade, and steroid hormone receptor negativity. Univariate analysis of the entire data set showed that high TK levels were related to shorter DSS (P < 10-5), LRI (P < 10-3), and DRI (P < 10-5). In time-dependent Cox model...

TGF-β – an excellent servant but a bad master

Abstract: The transforming growth factor (TGF-β) family of growth factors controls an immense number of cellular responses and figures prominently in development and homeostasis of most human tissues. Work over the past decades has revealed significant insight into the TGF-β signal transduction network, such as activation of serine/threonine receptors through ligand binding, activation of SMAD proteins through phosphorylation, regulation of target genes expression in association with DNA-binding partners and regulation of SMAD activity and degradation. Disruption of the TGF-β pathway has been implicated in many human diseases, including solid and hematopoietic tumors. As a potent inhibitor of cell proliferation, TGF-β acts as a tumor suppressor; however in tumor cells, TGF-β looses anti-proliferative response and become an oncogenic factor. This article reviews current understanding of TGF-β signaling and different mechanisms that lead to its impairment in various solid tumors and hematological malignancies.

Microbial Dysbiosis Is Associated with Human Breast Cancer

Abstract: Breast cancer affects one in eight women in their lifetime. Though diet, age and genetic predisposition are established risk factors, the majority of breast cancers have unknown etiology. The human microbiota refers to the collection of microbes inhabiting the human body. Imbalance in microbial communities, or microbial dysbiosis, has been implicated in various human diseases including obesity, diabetes, and colon cancer. Therefore, we investigated the potential role of microbiota in breast cancer by next-generation sequencing using breast tumor tissue and paired normal adjacent tissue from the same patient. In a qualitative survey of the breast microbiota DNA, we found that the bacterium Methylobacterium radiotolerans is relatively enriched in tumor tissue, while the bacterium Sphingomonas yanoikuyae is relatively enriched in paired normal tissue. The relative abundances of these two bacterial species were inversely correlated in paired normal breast tissue but not in tumor tissue, indicating that dysbiosis is associated with breast cancer. Furthermore, the total bacterial DNA load was reduced in tumor versus paired normal and healthy breast tissue as determined by quantitative PCR. Interestingly, bacterial DNA load correlated inversely with advanced disease, a finding that could have broad implications in diagnosis and staging of breast cancer. Lastly, we observed lower basal levels of antibacterial response gene expression in tumor versus healthy breast tissue. Taken together, these data indicate that microbial DNA is present in the breast and that bacteria or their components may influence the local immune microenvironment. Our findings suggest a previously unrecognized link between dysbiosis and breast cancer which has potential diagnostic and therapeutic implications.

A multicolor nanoprobe for detection and imaging of tumor-related mRNAs in living cells.

Abstract: Cancer is a leading cause of death worldwide and accounts for several millions of deaths every year. The survival of cancer patients is strongly associated with the stage of the tumor at the time of diagnosis. Identifying the cancer at the cellular level in an early stage before metastasis holds great promise for increasing the survival of cancer patients. A major focus of research towards this goal is on the estimation of abnormalities in gene expression in living cells. Tumor-related mRNA has been widely used as a specific marker to assess the migration of tumor cells locally or in the bloodstream. Changes in the level of tumor-related mRNA expression are correlated with tumor burden and malignant progression. The detection of tumor-related mRNA markers in intact cancer cells provides new tools for identifying cancer cells in clinical samples. Recently, a variety of techniques have been exploited to monitor tumor-related mRNAs. Among these methods, fluorescence imaging analysis offers an appealing approach for the detection of cancer at the cellular level, which may be of prognostic significance. Many fluorescence probes have been synthesized for the detection and imaging of mRNA in cancer cells and most of the research focuses on detecting a single type of mRNA, which may yield false positive results and limits the development of intracellular mRNA imaging and detection. Notably, cancer is associated with multiple tumor-related mRNAs, and some mRNA markers are expressed in normal cells. Simultaneous detection of multiple targets brings new opportunities for improving the accuracy of early cancer detection over the single-marker assay. Although various types of platforms for the detection of multiple targets have been developed, none have been designed for imaging three or more markers in living cells. Such intracellular imaging techniques for multiple tumorrelated mRNAs could promote the progress of early cancer detection. Herein, we describe a multicolor fluorescence nanoprobe based on nanoflares, which simultaneously detects three intracellular tumor-related mRNAs. The nanoprobe consists of gold nanoparticles (Au NPs) functionalized with a dense shell of recognition sequences (synthetic oligonucleotides) hybridized to three short dye-terminated reporter sequences by gold–thiol bond formation (Figure 1). The recognition sequences contain 21-base recognition elements for three specific mRNA transcripts: c-myc mRNA, TK1 mRNA, and GalNAc-T mRNA.