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S Robine

Publications and source records attributed to S Robine.

27 records · Page 2Linked to original sources
PubMed1988

Villin expression in the visceral endoderm and in the gut anlage during early mouse embryogenesis.

Villin is an evolutionarily well conserved, Ca2+ regulated actin-binding protein, and a major structural component of the brush border of specialized absorptive cells. Using paraffin sections and an affinity purified polyclonal anti-villin antibody, we have investigated the early expression of villin during mouse embryogenesis. Villin is first detectable at the early post-implantation stage in visceral endodermal cells at the periphery of the egg cylinder. In this extra embryonic layer, the expression of villin increases and then persists until full term gestation. In the embryo, villin first appears in gut anlage during the axial rotation. Using the same methodology, villin expression is also demonstrated in differentiating embryoid bodies from a teratocarcinoma. Both in extra embryonic and embryonic extracts, villin expression is confirmed by immunoblot and Northern blot analysis which reveal, respectively, a single polypeptide of 93 kd and an mRNA of 3.4 kb in length, two well defined parameters for adult mouse villin gene expression. The results presented here show that paraffin sections allow very sensitive and highly resolutive detection of antigens in early embryogenesis. They provide a detailed developmental profile of villin expression and demonstrate the usefulness of villin as a marker for epithelial cells involved in absorptive processes.

Animals↗
PubMed1987

Villin: a cytoskeletal protein and a differentiation marker expressed in some human adenocarcinomas.

We studied the expression of villin, a microfilament-associated, actin-binding protein typical of brush-border microvilli, in a variety of human carcinomas by applying immunofluorescence microscopy to frozen sections and immunoblotting methods to tissue extracts using a rabbit antiserum and a monoclonal antibody specific for villin. All of the 24 primary and metastatic colorectal adenocarcinomas tested were uniformly and strongly positive for villin, with the immunocytochemical labeling concentrated at the luminal cell margin. In poorly differentiated tumor areas, rudimentary tubules were stained. All of the six tubular adenocarcinomas of the stomach studied as well as two adenocarcinomas of the gall bladder and a hepatocellular carcinoma were also villin-positive. Villin was detectable in 12 of 14 adenocarcinomas of the pancreas; in some of these cases, its distribution was heterogeneous. Among 21 renal cell carcinomas investigated, positivity for villin was seen in nine of 13 clear cell tumors (especially those of grade II), and in all four chromophilic cell tumors; however, all four chromophobe cell tumors studied were negative. Four of 11 endometrial but none of nine ovarian carcinomas were (uniformly or focally) villin positive. Of 18 adenocarcinomas of the lung studied, one was uniformly and four focally positive for villin, while the remainder were negative. All of the other epithelial tumors studied, including 12 adenocarcinomas of the breast and seven epithelial or biphasic pleural mesotheliomas, were villin negative. Our results show that the expression of villin in intestinal epithelial cells is consistently maintained in their corresponding carcinomas, even when the organized brush-border structure has been lost. The presence of villin in some endometrial and pulmonary adenocarcinomas--in contrast to its absence in the respective normal epithelia--suggests that this protein is newly expressed during hyperplasia, dysplasia, or carcinogenesis. Determining the presence or absence of villin and its immunocytochemical staining pattern in metastatic adenocarcinomas may be of some help in determining the type and site of the primary tumor.

Adenocarcinoma↗
PubMed1987

Changes in villin synthesis and subcellular distribution during intestinal differentiation of HT29-18 clones.

Brush border in enterocytes is a cell surface specialization intimately associated with terminal differentiation of these cells. HT29-18, a clone derived from the HT-29 human colonic adenocarcinoma cell line, and HT29-18-C1, a subclone from HT29-18 described in the companion paper (Huet, C., C. Sahuquillo-Merino, E. Coudrier, and D. Louvard, 1987, J. Cell Biol., 105:345-357), undergo terminal differentiation with brush borders in the absence of glucose or upon replacement of glucose by galactose in the medium. Taking advantage of this clone and its subclone which can be manipulated in vitro, we have studied the synthesis and subcellular distribution of villin, one major protein in the microvillus core of the brush border. For this study, a monoclonal antibody against villin (BDID2C3) has been isolated and characterized in detail. In addition an ELISA has been set up to measure villin accurately in total cell extracts. Villin content in differentiated HT29-18 cells is close to that seen in normal human colonic cells but 10 times lower in undifferentiated HT29-18 cells. The rate of villin synthesis is dramatically increased in the course of enterocytic differentiation, while villin is remarkably stable after synthesis. We have recently shown, using a cDNA probe for villin, that this change is controlled either at the transcription level or by RNA stabilization (Pringault, E., M. Arpin, A. Garcia, J. Finidori, and D. Louvard, 1986, EMBO (Eur. Mol. Biol. Organ.) J., 5:3119-3124). As shown by immunofluorescence and immunogold labelings, villin is targeted to the brush border area of differentiated HT29-18 cells but remains diffusely distributed in undifferentiated ones.

Adenocarcinoma↗
PubMed1987

Stage-specific polypeptides and villin expression during the intestinal epithelium substitution of the metamorphosing amphibian.

The amphibian intestinal epithelium provides an excellent aid to study the developmental pattern of protein synthesis during cell life. The metamorphosing tissue demonstrates a kaleidoscope of cell degeneration, proliferation and differentiation. These events occur at specific period in a synchronized cell population. Two-dimensional gel electrophoresis, together with histological studies, has been used to examine the changes in the patterns of protein synthesis during intestinal epithelium substitution in metamorphosing Alytes obstetricians larvae. Of the approximately 280 polypeptides detected by this method, 24 show major changes in their patterns of synthesis. Five polypeptides are only synthesized during the larval period and are characteristic of the primary epithelium. Six polypeptides are characteristic of the secondary intestinal epithelium, as they are only detected in the newly-metamorphosed juvenile. Four polypeptides of Mr 81,000, 78,000, 42,000 (pI, 5.1 and 6.2) are characteristic of the epithelium crisis, as they are only detected during climax. They may represent molecular markers of growing stem cells. On the other hand, two polypeptides, of Mr 66,500 and 63,500, are not synthesized during this critical period, but are synthesized before and after metamorphosis. Seven polypeptides show changes in the relative rate of their synthesis during metamorphosis of the intestinal epithelium. Among them, the protein of Mr 105,000 which presents two isoelectric variants (pI 5.5 and 5.55) is immunologically related to villin. Expression of this protein has been studied using immunoblotting of cell extracts onto nitrocellulose and immunodetection in tissue sections. The protein is localized in the brush border of primary and secondary epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Can villin be used to identify malignant and undifferentiated normal digestive epithelial cells?

We have investigated the presence of villin (a Ca2+-regulated actin binding protein) in various tissues (normal or malignant) and in established cell lines by using sensitive immunochemical techniques on cell extracts and immunofluorescence analysis on frozen sections. Our results show that villin is a marker that can be used to distinguish normal differentiated epithelial cells from the simple epithelia lining the gastrointestinal tract and renal tubules. Villin is found in the absorptive cells of the small and large intestines, in the duct cells of pancreas and biliary system, and in the cells of kidney proximal tubules. Furthermore, undifferentiated normal and tumoral cells of intestinal origin in vivo and in cell culture express villin. Therefore, expression of villin is seen in cells that do not necessarily display the morphological features characteristic of their terminally differentiated state, such as the microvilli-lined brush border. We suggest the possible clinical implications of using villin as a marker in the diagnosis of metastatic adenocarcinomas.

Animals↗
PubMedDate not supplied

Illegitimate villin transcripts in normal bone marrow precludes detection of colon cancer micrometastases.

Villin is a specific marker for normal and tumoral colon tissue. We have developed a highly sensitive assay using reverse transcription (RT) and real-time PCR to detect villin transcripts. The sensitivity of detection is one colon cancer cell. However, high levels of illegitimate villin transcripts were observed in normal bone marrow, precluding the use of villin RT-PCR for routine detection of colon cancer cells in bone marrow of patients with colon cancer.

Biomarkers↗
PubMedDate not supplied

Expression patterns of L-plastin isoform in normal and carcinomatous breast tissues.

Plastins are members of a family of actin-binding proteins which exhibit a tissue-specific expression pattern. L-plastin, which is specifically expressed in hematopoietic cell lineage, has been proposed to be involved in the control of cell adhesion and motility. This protein is also frequently expressed in cell lines derived from mammary solid tumors and therefore might be involved in cancer invasion and metastasis. We have analysed plastin expression in normal and carcinomatous breast tissues in vivo by immunohistochemistry and immunoblotting approaches using specific plastin isoform antibodies. L-plastin was not detected in normal epithelial cells of the mammary gland whereas a staining of myoepithelial cells was observed in 50% of the cases. In breast carcinomas, a significant immunostaining of malignant epithelial cells was observed in 4 of the 29 cases analysed (13.8%). No correlation between L-plastin expression and tumor size, histological grade or lymph node status was observed. In contrast, L-plastin was found expressed in 4 of the 11 estrogen and progesterone receptors negative tumors (p = 0.039). The potential role of plastin expression in the tumor process is discussed.

Adult↗