Biomedical subjects
Publications and source records attributed to P Birembaut.
We report a very rare case of ovarian gastrinoma in the context of multiple endocrine neoplasia type I, including primary hyperparathyroidism and Zollinger-Ellison syndrome. Somatostatin receptor scintigraphy revealed the ovarian involvement at an early stage. Oophorectomy led to the final diagnosis and complete healing.
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Membrane-type matrix metalloproteinase 1 (MT1-MMP) is a membrane-anchored matrix metalloproteinase (MMP) that is frequently associated with processes involving tissue remodelling and cell migration. We have examined MT1-MMP expression and subcellular distribution as a function of MCF10A mammary epithelial cell migration using an in vitro outgrowth migration assay. Stronger expression of MT1-MMP was observed at the mRNA and at the protein level in cells at the periphery of the outgrowth. As shown by videomicroscopy, these cells were involved in an orientated cell migration, in contrast to stationary cells distant from the periphery. Furthermore, MT1-MMP was mainly distributed in lamellipodia of migratory cells, as well as at their basal surface in contact with the substrate. Laminin-5 (Ln-5), a recently described substrate for MT1-MMP, was deposited preferentially in the matrix by migratory cells. Fragments of the gamma2 subunit of Ln-5 were also identified in migratory cultures of MCF10A cells, attesting to its proteolytic degradation. These fragments corresponded in size to those we observed after incubation of purified human Ln-5 with the recombinant catalytic domain of human MT1-MMP. We also show that anti-Ln5 blocking antibodies, MMP inhibitors (BB94 and TIMP-2) and MT1-MMP antisense oligonucleotides significantly decreased MCF10A cell migration. Taken together, these observations demonstrate that MT1-MMP is spatially and temporally regulated during MCF10A cell migration, and suggest that MT1-MMP-mediated pericellular proteolysis of Ln-5 gamma2 chain could contribute to this process.
AIM: As human papillomavirus (HPV) infection is a significant risk factor for cervical cancer, the aim of this study was to assess the efficacy of HPV detection techniques in predicting the presence or the development of a high-grade squamous intra epithelial lesion. Additional reasons for carrying out this investigation were as follows. It was considered that the clinical value of HPV typing may have been underestimated in certain previous reports, which based their findings on first-generation assays. Moreover, until the present investigation most studies only investigated the cases with abnormal smear findings and did not include long-term follow-up, nor detailed follow-up of women with a normal smear but positive HPV typing, although this patient subgroup is of particular interest. The patient population included 3778 women who underwent routine cytological cervical screening and who gave their informed consent to participate in this study, consisting of a cervical smear, HPV testing via a second-generation Hybrid Capture II assay (which is more sensitive than first-generation tests, and can detect 18 different HPV types, i.e., 13 oncogenic and five non-oncogenic types); and in the case of abnormal smear findings, colposcopic examination and directed biopsies of the sites of suspected lesions. The women with cytomorphologically normal cervical smears but which who HPV-positive were reexamined six months later. RESULTS: HPV findings were positive in 66 cases where the initial smear indicated the presence of a high-grade lesion with the diagnosis confirmed by biopsy in 65 cases; in 155 cases (76.1%) where the initial smear indicated the presence of a low-grade lesion; in 44 (57.1%) out of 77 smears indicating the presence of ASCUS-type (atypical squamous cells of undetermined significance) lesions; and in 366 cases (10.5%) of apparently normal initial smears. After colposcopy and follow-up, a final diagnosis of high-grade lesion was made for 85 patients. All these patients were found to have high-risk (oncogene-positive) HPV at the first examination, but in only 65 cases (76.5%) was the initial smear indicative of a high-grade lesion. Finally, in the patient groups with low-grade or ASCUS-type smear findings or with an apparently normal smear, a high-grade lesion was only found in those patients with persistent high-risk HPV infection. In all, the sensitivity of the Hybrid Capture II assay in detecting high-grade lesions was 100% versus 85.9% for standard cytology. However, its specificity (86.3%) and positive predictive value were not as high as the latter. CONCLUSION: The results of this study indicate that HPV typing via this second-generation assay displays good sensitivity for the detection of at-risk cases, i.e., those involving the presence or development of high-grade cervical lesions. However, a number of issues have to be addressed before HPV typing is adopted in clinical practice, such as the fairly high HPV prevalence in women aged over 60 years, and whether the implications of this are the same as for younger age groups. Also, the present cost of complete typing remains too high for it to be used on a widespread scale. Nevertheless, HPV typing may have a useful role to play in the detection of cervical cancer.
Interleukin-4 (IL-4) is a pleiotropic cytokine that is able to activate connective tissue cells and stimulate the accumulation of extracellular matrix macromolecules. In this report, the expression of IL-4 in normal wound healing was studied by immunohistochemistry. The effects of exogenous IL-4 or IL-4 antisense oligonucleotides administration were also studied in mouse experimental wounds. IL-4 expression was detected in the lower dermis below the wound as early as Day 1 after wounding. IL-4 expression was maximal by Day 4, then decreased progressively, and completely disappeared by Day 21 after wounding. Topical administration of IL-4 on experimental wounds in mice significantly accelerated the rate of healing, whereas IL-4 antisense oligonucleotides significantly inhibited healing. These results demonstrate that IL-4 may be implicated in normal wound healing.
The reliability of the Hybrid Capture II (HC-II; Digene, Silver Spring, MD, U.S.A.) assay was tested in detecting 18 human Papillomavirus (HPV) types for the screening of cervical lesions. Cytology, HPV testing, colposcopy, and biopsy were used to monitor 204 women with normal smears at the first entry. The median follow-up was 15 months (range, 4-27 months). The primary endpoint was clinical progression defined as the presence of a cervical intraepithelial lesion at the biopsy. In the patient population of 204 HPV-infected women, 81 (39.7%) had a persistent HPV infection at two or three examinations with a final histologic diagnosis of 14 high-grade and 13 low-grade squamous intraepithelial lesions (SIL) within 4 to 22 months. Women with regressive HPV infection did not develop any lesion during the same period. The evaluation of the viral load of high-risk HPV by the HC-II did not represent a sensitive approach to predict the persistence or the apparition of high-grade lesions. Thus, persistent high-risk HPV infection detected with HC-II represents a reliable tool to select populations at risk for the development of high-grade cervical lesions.
During tumor progression, the extracellular matrix (ECM) and particularly the basement membrane (BM) appear to be dynamic structures that are not only degraded but also deposited around tumor clusters. In this study we examined by immunohistochemistry the localization of three chains of Type IV collagen (alpha1, alpha3 and alpha5), Type VII collagen, and laminin 5 at different stages of bronchopulmonary cancers. In normal tissues, alpha1(IV) chain was detected in all BMs (bronchial, vascular, alveolar, and glandular), alpha5(IV) chain was present only in vascular BM, and laminin 5 and Type VII collagen were co-localized in bronchial and glandular BMs, whereas alpha3(IV) immunolabeling was totally absent from normal bronchi. In well-differentiated carcinomas, alpha3(IV) chain staining was found in some neosynthetized BMs interfacing the tumor cell and the stromal compartment, contrasting with the total absence of labeling in normal tissues. alpha1(IV) chain showed strong reactivity in all BM. Laminin 5 and Type VII collagen were also detected in neosynthetized BM. In poorly differentiated invasive cancers, alpha3(IV) chain and Type VII collagen were not found, whereas laminin 5 and alpha1(IV) chain persisted. The most important modifications in BM composition during tumor progression therefore appear to be the appearance of the alpha3 (IV) chain in well-differentiated carcinomas and its subsequent disappearance in poorly differentiated carcinomas, together with the loss of type VII collagen. alpha5(IV) chain distribution was restricted in vascular BM of well- and poorly differentiated carcinomas. These results show that the composition of BM is modified during the progression of bronchopulmonary tumor, emphasizing that the BM represents a dynamic element in tumor progression and has an important role in tumor cell invasiveness.
Previous studies have emphasized the usefulness of DNA ploidy measurement and Human Papillomavirus (HPV) detection as prognostic markers in low grade cervical lesions. We addressed the eventual relationship between HPV type, DNA profile, and p53 tumor suppressor protein expression in anal condylomata acuminata to eventually determine parameters which may be considered as predictive risk factors for the development of cancer. DNA ploidy was assessed by image cytometry after Feulgen staining of contiguous serial sections of 45 anal condylomata acuminata without atypia containing HPV detected by in situ hybridization and Polymerase Chain Reaction (PCR). p53 expression was detected by immunohistochemistry. DNA aneuploidy was found in 53.3% of these lesions, 48.9% containing non oncogenic HPV types 6 and/or 11 and 4.4% harbouring HPV types 11 and 18. The DNA diploid lesions were all associated with non oncogenic HPV types 6 and/or 11 and one case also contained HPV type 33. There was no significant correlation between the detection of DNA aneuploidy and the presence of immuno-detected p53. DNA aneuploidy was not related to the presence of oncogenic HPV in anal condylomata acuminata. The DNA aneuploid profile frequently observed, especially in lesions associated with non oncogenic HPV types, is not yet well explained and cannot be considered as a prognostic factor. In contrast, a more intensive clinical follow-up should be proposed in patients with oncogenic HPV associated to DNA aneuploidy.
Twenty patients with severe Schönlein-Henoch nephritis were selected on a histologically basis of diffuse proliferative endo- and/or extracapillary glomerulonephritis during a period of 12 years in Champagne-Ardenne. There were 15 men and 5 women, mean age 44.1 years. An infectious history was found in 40%, an urinary tract cancer in 15%. In all cases there was purpura, in 80% joint pain and in 50% digestive symptoms. Clinical presentation at diagnosis included, in all cases, hematuria (gross in 50%) and proteinuria (of nephrotic range in 80%); there was hypertension in 60% and renal failure in 80%. Histology found, in all cases, mesangial IgA and often C3 deposits, with a diffuse endocapillary proliferation in 10%, extra-capillary proliferation in 30% and both endo-extracapillary in 60%; 45% of the patients had crescents in greater than 50% of glomeruli. The outcome, after steroid and immunosuppressive treatment, was end-stage renal failure in 25%, moderate renal failure in 20%, or normal renal function in 55% with a mean follow-up period of 4.6 years. These severe nephritis were associated with repetitive and often necrotic purpura, frequent joint pain and severe digestive symptoms. The analysis of initial renal presentation confirmed the bad prognosis of nephrotic syndrome, renal failure and especially hypertension, which were well correlated with the severity and diffusion of proliferative lesions. Despite a worse known prognosis, these nephritis responded to an aggressive and early treatment.
Cell spreading and migration associated with the expression of the 92-kD gelatinase (matrix metalloproteinase 9 or MMP-9) are important mechanisms involved in the repair of the respiratory epithelium. We investigated the location of MMP-9 and its potential role in migrating human bronchial epithelial cells (HBEC). In vivo and in vitro, MMP-9 accumulated in migrating HBEC located at the leading edge of a wound and MMP-9 expression paralleled cell migration speed. MMP-9 accumulated through an actin-dependent pathway in the advancing lamellipodia of migrating cells and was subsequently found active in the extracellular matrix (ECM). Lamellipodia became anchored through primordial contacts established with type IV collagen. MMP-9 became amassed behind collagen IV where there were fewer cell-ECM contacts. Both collagen IV and MMP-9 were involved in cell migration because when cell-collagen IV interaction was blocked, cells spread slightly but did not migrate; and when MMP-9 activation was prevented, cells remained fixed on primordial contacts and did not advance at all. These observations suggest that MMP-9 controls the migration of repairing HBEC by remodeling the provisional ECM implicated in primordial contacts.
Invasiveness and metastatic capacity of tumor cells have been related to increased expression and activation of gelatinase-A (MMP-2). 9-octadecenoic acid (oleic acid, OA), a long-chain cis-unsaturated fatty acid, has been shown to partially inhibit the formation of lung metastatic colonies in an ex vivo model of implantation of metastatic cells into nude mice. Reduction of metastasis formation was suggested to be due to a decrease of MMP-2 activity in tumor tissue extracts. Since regulation of MMP-2 activity occurs at different levels, including gene expression, pro-enzyme activation and finally active enzyme inhibition, we here investigated the precise level of the inhibitory effect of OA on MMP-2 activity by oncogene-transformed human bronchial epithelial cells (BZR cells). OA, at the dose of 5 x 10(-5) M, was shown to inhibit by 50% MMP-2 activity released from BZR cells. Northern-blot analysis of mRNA encoding MMP-2, MT1-MMP, the physiological activator of MMP-2, and TIMP-2, the natural inhibitor of MMP-2, revealed that OA did not alter the steady-state levels of MMP-2, MT1-MMP and TIMP-2 mRNA. Also, gelatin zymography demonstrated that the extent of MMP-2 activation was not modified by OA treatment. On the contrary, OA could inhibit the fluorogenic quenching substrate (7-methoxycoumarin-4-yl)acetyl-L-Pro-Leu-Gly-Leu-[N-3-(2,4-dinitrophenyl)-L-2, 3-diaminopropionyl]-Ala-Arg-NH2 (Mca-Pro-Leu-Gly-Leu-Dpa-Ala-Arg-NH2) hydrolysis by recombinant MMP-2 with Ki = 4.3 microM. These data suggest that the beneficial influence of OA on the formation of lung metastatic colonies was independent of its influence on MMP-2 expression and/or activation, but could be attributed to inhibition of MMP-2 activity.
Hybrid Capture II (HC-II) is a commercial human papillomavirus (HPV) detection test designed to detect 18 HPV types divided into high-risk and low-risk groups. We have tested 1647 scrapes from 1518 unselected women attending routine cytological screening by this assay for the detection of histologically proven high-grade lesions. The reliability of this test was also evaluated on 117 fresh cone biopsy samples. HPV DNA has been detected in 400 scrapes (24.3%), 296 containing a high-risk HPV (18.0%). All the smears evocative of high-grade lesions were positive for high-risk HPV, and high-risk HPV were detected in all the 34 cases presenting a histologically proven high-grade lesion and in 68 (97.1%) of the 70 cone biopsy samples showing a high-grade lesion or an invasive carcinoma. Thus, the sensitivity was superior to the sensitivity of cytology (85.3%). Nevertheless, the quantitative approach provided by the HC-II assay for the assessment of the viral load could not clearly distinguish among cases with or without high-grade lesions. Thus this assay is recommended for the screening of high-grade lesions on a large scale, in association with classic cytology.
We investigated the expression and activation of matrix metalloproteinases in a model of experimental wounds in rats, and their modulation by glycyl-L-histidyl-L-lysine-Cu(II), a potent activator of wound repair. Wound chambers were inserted under the skin of Sprague-Dawley rats and received serial injections of either 2 mg glycyl-L-histidyl-L-lysine-Cu(II) or the same volume of saline. The wound fluid and the neosynthetized connective tissue deposited in the chambers were collected and analyzed for matrix metalloproteinase expression and/or activity. Interstitial collagenase increased progressively in the wound fluid throughout the experiment. Glycyl-L-histidyl-L-lysine-Cu(II) treatment did not alter its activity. Matrix metalloproteinase-9 (gelatinase B) and matrix metalloproteinase-2 (gelatinase A) were the two main gelatinolytic activities expressed during the healing process. Pro-matrix metalloproteinase (pro-form of matrix metalloproteinase)-9 was strongly expressed during the early stages of wound healing (day 3). In the wound fluid, it decreased rapidly and disappeared after day 18, whereas in the wound tissue, matrix metalloproteinase-9 expression persisted in the glycyl-L-histidyl-L-lysine-Cu(II) injected chamber until day 22. Pro-matrix metalloproteinase-2 was expressed at low levels at the beginning of the healing process, increased progressively until day 7, then decreased until day 18. Activated matrix metalloproteinase-2 was present in wound fluid and wound tissue. It increased until day 12, then decreased progressively. Glycyl-L-histidyl-L-lysine-Cu(II) injections increased pro-matrix metalloproteinase-2 and activated matrix metalloproteinase-2 during the later stages of healing (days 18 and/or 22). These results demonstrate that various types of matrix metalloproteinases are selectively expressed or activated at the various periods of wound healing. Glycyl-L-histidyl-L-lysine-Cu(II) is able to modulate their expression and might significantly alter wound remodeling.
Tumor cells interact with stromal cells via soluble or cell-bound factors stimulating the production of matrix metalloproteinases (MMPs), a group of enzymes largely involved in the extracellular matrix (ECM) remodeling in tumor invasion. Among these factors, extracellular matrix metalloproteinase inducer (EMMPRIN) has been shown to stimulate in vitro the fibroblast production of various MMPs such as interstitial collagenase (MMP-1), stromelysin-1 (MMP-3), and gelatinase A (MMP-2). In this study, the EMMPRIN protein was detected by immunohistochemistry prominently in malignant proliferations of the breast and the lung. It was present at the surface of both tumor epithelial and peritumor stromal cells. Because previous studies have reported that stromal cells do not express EMMPRIN mRNAs, it is very likely that EMMPRIN is bound to stromal cells via a specific receptor. Moreover, our observations also demonstrated that the same peritumor stromal cells strongly express MMP-2. Our results show that EMMPRIN is an important factor in tumor progression by causing tumor-associated stromal cells to increase their MMP-2 production, thus facilitating tumor invasion and neoangiogenesis. (J Histochem Cytochem 47: 1575-1580, 1999)
Vimentin expression in human mammary epithelial MCF10A cells was examined as a function of their migratory status using an in vitro wound-healing model. Analysis of the trajectories of the cells and their migratory speeds by time lapse-video microscopy revealed that vimentin mRNA and protein expression were exclusively induced in cells at the wound's edge which were actively migrating towards the center of the lesion. Actin labeling showed the reorganization of actin filaments in cells at the wound's edge which confirmed the migratory phenotype of this cell subpopulation. Moreover, the vimentin protein disappeared when the cells became stationary after wound closure. Using cells transfected with the vimentin promoter controlling the green fluorescent protein gene, we also demonstrated the specific activation of the vimentin promoter in the migratory cells at the wound's edge. Transfection of the antisense vimentin cDNA into MCF10A cells clearly reduced both their ability to express vimentin and their migratory speed. Taken together, these observations demonstrate that vimentin is transiently associated with, and could be functionally involved in, the migratory status of human epithelial cells.
Wear debris of polyethylene prosthetic components is known to induce a host granulomatous reaction which recruits numerous macrophages and multinucleated giant cells. By releasing cellular mediators of a nonspecific inflammatory reaction, activated phagocytic cells are thought to play a key role in osteolysis leading to aseptic loosening of the prosthesis. Matrix metalloproteinases (MMPs) have been implicated in this destructive process by their ability to degrade extracellular matrix components of bone and adjacent connective tissue. To investigate the roles of gelatinase A, its activator MT1-MMP, and the MMP inhibitors TIMP-1 and TIMP-2 in aseptic loosening of polyethylene prostheses, immunohistochemistry (IHC) and in situ hybridization (ISH) were performed on periprosthetic pseudosynovial interface tissues. Gelatinase A and MT1-MMP were strongly detected immunohistochemically in macrophages and multinucleated giant cells in contact with polyethylene wear debris. In contrast to MT1-MMP, gelatinase A mRNAs were not found in phagocytic cells but in surrounding fibroblasts, thereby suggesting cooperation between macrophages and fibroblasts in this process. While TIMP-1 was expressed essentially in hyperplastic pseudosynoviocytes as assessed by IHC and ISH, TIMP-2, MT1-MMP, and gelatinase A were colocalized in phagocytic cells. These data support the concept of progelatinase A activation involving a trimolecular complex (MT1-MMP-TIMP-2-gelatinase A) mechanism. Thus, this study demonstrated that gelatinase A and its activator might contribute to the aseptic loosening of polyethylene prostheses.
Matrix metalloproteinases (MMPs) represent a group of enzymes involved in the degradation of most of the components of the extracellular matrix and therefore participate in tumoural invasion. MMPs, especially gelatinases A and B, MT1-MMP, the activator of gelatinase A, and stromelysin-3 were found overexpressed in many cancers including bronchopulmonary carcinomas. In vivo observations revealed that fibroblasts are the principal source of production of MMPs. Some of these enzymes such as MT1-MMP and stromelysin 3, displayed a focal stromal localisation near preinvasive and invasive tumour clusters. Furthermore, some tumour cell lines were shown to stimulate the expression of MT1-MMP by fibroblasts. All these in vivo and in vitro results suggest that certain tumour cells produce diffusible factors which could influence the MMP stromal expression. Among these factors, the TCSF (Tumor Collagenase Stimulatory Factor) which is known to upregulate some MMPs in vitro could be a good candidate for this stromal regulation, since it is produced by bronchial tumour cells in vivo. In this review, we address such a cooperation between tumour and stromal cells for the production of MMPs and emphasize their necessity for tumoural progression in bronchopulmonary carcinomas.
Titrated Extract from Centella asiatica (TECA) is a drug which has been used for many years in Europe for the treatment of wound healing defects. It is a reconstituted mixture of 3 triterpenes extracted from the plant, asiatic acid, madecassic acid and asiaticoside. In this report, we studied the effects of TECA and its separated components in the wound chamber model described by Schilling et al. Stainless steel wound chambers were surgically inserted under the skin of rats and received serial injections of either TECA or its purified components. Chambers were collected at days 7, 14, 21 or 28 for biochemical analysis or histological examination. TECA-injected wound chambers were characterized by increased dry weight, DNA, total protein, collagen and uronic acid contents. Peptidic hydroproline was also increased, showing an increased remodeling of the collagen matrix in the wound. The 3 purified components of TECA were all able to reproduce the effects of the complete drug, with some differences depending on the product. Asiatic acid and asiaticoside were the most active of the 3 triterpenes. Asiaticoside exerted a preferential stimulation of collagen synthesis and was active at low doses only. In addition to collagen, the 3 components were also able to stimulate glycosaminoglycan synthesis.