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G K Koukoulis

Publications and source records attributed to G K Koukoulis.

At least 19 recordsLinked to original sources
PubMed2006

Clinical significance of organ- and non-organ-specific autoantibodies on the response to anti-viral treatment of patients with chronic hepatitis C.

BACKGROUND: Development of organ- and non-organ-specific autoantibodies has been reported in hepatitis C virus patients treated with interferon-alpha plus/minus ribavirin. AIMS: To address whether prevalence and the titre of gastric parietal autoantibodies and non-organ-specific autoantibody in hepatitis C virus-treated patients were affected by therapy, and if the development of these antibodies carries any clinical significance on the response to treatment, as few studies in adults have been strictly designed to address the above hypothesis. METHODS: Samples at three time-points (baseline, end of treatment, end of follow-up) from 102 hepatitis C virus patients (39 sustained responders, 26 relapsers, 33 non-responders; four lost in follow-up) were studied for gastric parietal autoantibodies and/or non-organ-specific autoantibody by indirect immunofluorescence, commercial and in-house enzyme-linked immunosorbent assays. RESULTS: Sustained virological and biochemical response was associated with antinuclear antibody absence (end of treatment or end of follow-up), decrease of smooth-muscle antibody titres during therapy and gastric parietal autoantibodies negativity at baseline. However, after multivariate analysis only antinuclear antibody positivity at the end of treatment and increase of smooth-muscle antibody titres were associated with worst treatment response, independently of known factors of worst treatment outcome. CONCLUSIONS: We were able to demonstrate a negative correlation between the efficacy of anti-viral treatment for hepatitis C virus and the presence of antinuclear antibody and smooth-muscle antibody before treatment, or their increase during therapy.

Adult↗
PubMed2002

Epidermal growth factor receptor expression in invasive thymoma.

PURPOSE: Epidermal growth factor receptor (EGFR) is a transmembrane glycoprotein with intrinsic tyrosine kinase activity. Activation results in a variety of cellular responses including cell proliferation and differentiation. In clinical trials, anti-EGFR is showing promise in the treatment of solid tumors expressing EGFR. Thus, we assessed EGFR expression in a series of thymic epithelial tumors. METHODS: Tumors from 37 patients seen at Indiana University School of Medicine (IUMC) for treatment of thymoma (31 patients) or thymic carcinoma (six patients) were assessed for EGFR expression. Five-micron sections of formalin-fixed, paraffin-embedded tumor (28 invasive and/or metastatic thymomas, six thymic carcinomas, and three non-invasive thymomas) were stained with anti-EGFR. Any degree of cytoplasmic membrane staining of tumor cells was considered positive; furthermore, staining was scored 0 to 3+ using criteria as standardized for HER-2/neu assessment of breast carcinoma. Appropriate controls were performed. RESULTS: Positive staining of tumor was observed in 28 tumors (23 invasive and/or metastatic thymomas, two thymic carcinomas, and three non-invasive thymomas). CONCLUSIONS: EGFR is expressed in a high percentage of thymic epithelial tumors. EGFR is often strongly expressed and is a potential therapeutic target in patients with malignant thymic tumors. We are pursuing additional studies to assess anti-EGRF in the treatment of patients with advanced thymoma.

Adult↗
PubMed2001

Cholangiocytic apoptosis in chronic ductopenic rejection.

The significance of cholangiocytic apoptosis as a mechanism of ductopenia in liver rejection remains controversial. In a previous study, the presence but not the extent of ductal apoptosis was assessed by electron microscopy. Other previously published studies using an in situ hybridization method (in situ end labeling) produced conflicting results (no apoptosis v massive apoptosis). We studied 47 liver needle biopsies from 8 patients with chronic ductopenic rejection confirmed by pathologic examination of the failed grafts. These biopsies were performed because of graft dysfunction, during a period of several months before retransplantation, and they showed cholangiocytic injury with progressive ductal paucity. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling (TUNEL) was used to detect apoptosis (tissue digestion with proteinase K 20 microg/mL for 20 minutes). The interlobular bile ducts did not show labeling, even in lymphocytic cholangitis with obvious epithelial injury. However, there was minimal staining of ductular nuclei. Lymphocytic nuclei were also labeled. Apoptosis was not detectable in the vanishing interlobular bile ducts, even when more representative samples were studied and a more sensitive method was used. Unless apoptosis of cholangiocytes is an exceptionally rapid process escaping detection by conventional methods, ductopenia results mainly from ordinary, nonprogrammed cholangiocytic death. Apoptosis could still be involved in the pathogenesis of ductopenia by depleting cholangiocytic precursors, generally presumed to reside in ductules. This is a possible mechanism suggested by the following: (1) the established role of apoptosis in the homeostatic control of immature/progenitor cells, (2) the paucity of ductular proliferation in chronic rejection, (3) the previously reported decrease of ductular bcl-2 expression in rejection, and (4) the sporadic ductular TUNEL labeling seen in this study.

Apoptosis↗
PubMed2001

Vitronectin in the cirrhotic liver: an immunomarker of mature fibrosis.

Vitronectin (Vn) is a multifunctional plasma glycoprotein produced by hepatocytes. Vn has been studied extensively as a cell adhesion molecule. However, its localization in the hepatic extracellular matrix has received relatively little attention. Cryosections of 5 normal liver samples and of 20 specimens showing posthepatitic cirrhosis were stained by the avidin-biotin complex method with a well-characterized monoclonal antibody to Vn. The extent and intensity of immunostaining were assessed semiquantitatively (0, no staining; 1+, weak focal staining; 2+, strong focal staining; 3+, strong diffuse staining). Paraffin sections from the same samples were stained with Masson trichrome (MT) and Shikata orcein (Or) methods. Frozen samples from selected cases were analyzed by Western blotting. In the normal liver, 3+ staining was limited to portal vessels. The portal tract connective tissue showed minimal staining (0 to 1+). Cirrhotic septa showed strong staining (2+). Septa lacking significant inflammation and composed of dense connective tissue, as indicated by MT and Or stains, showed the strongest Vn reactions (3+). Immunoblotting data strongly correlated with Vn increase in cirrhotic livers. Vn immunoreactivity is markedly increased in the cirrhotic liver matrix, regardless of the documented decrease in plasma Vn. Binding to collagen, elastin, and proteoglycans is the current favored mechanism of Vn deposition in tissues. Previous studies in cirrhotic patients showed increased affinity of plasma Vn to collagen. Vn is also increased in aged skin, associated with dermal elastic fibers. In other tissues, Vn deposition reflects chronicity of injury. Therefore, Vn immunoreactivity in liver can be considered a marker of fibrosis, especially of chronic/mature fibrosis, paralleling previous observations on enhanced orcein staining of cirrhotic septa. Immunolabeling of biopsy specimens with Vn and tenascin, a marker of ongoing remodeling or recently formed fibrous tissue, could be diagnostically helpful.

Biomarkers↗
PubMed1999

Enhanced tenascin expression correlates with inflammation in primary sclerosing cholangitis.

Tenascin (Tn) is an extracellular matrix (ECM) glycoprotein upregulated during development, repair and oncogenesis. In the normal adult liver, Tn is limited to vessels and, focally, to sinusoidal walls. In this study, samples were obtained from 12 livers removed during transplantation for primary sclerosing cholangitis (PSC). Paraffin sections were immunostained with monoclonal antibodies BC-4 which recognizes all isoforms of Tn and alpha-SMA-1 to alpha smooth muscle actin (alpha-SMA). Intense Tn reactions were noted in areas of ductular proliferation and inflammation at the parenchyma-stroma interface. In the absence of ductular proliferation, no selective Tn upregulation was noted. Staining was preferentially located adjacent to ductular basement membranes, with minimal extension into the surrounding ECM. Advanced histologic stages with micronodules rimmed by proliferating ductules showed the most florid Tn reactions, whereas fibrous septa and edematous perinodular haloes did not react. Increased periductal Tn was also seen associated with active inflammation, notably around large, dilated septal ducts, while fibro-obliterative ductal lesions and "onion skin fibrosis" did not stain. Focally enhanced Tn staining was noted in sinusoids neighboring ductular proliferation, and in dilated sinusoids within cirrhotic nodules. Reactions with alpha-SMA-1 highlighted myofibroblasts and activated Ito cells in topographic association with Tn reactions. We conclude that Tn is upregulated in PSC where it is preferentially localized in the remodeling matrix encompassing proliferating ductules and in altered periductal matrix. Our results suggest that Tn determinations in tissue or serum samples might be helpful in the clinical assessment of "activity" in PSC.

Actins↗
PubMed1997

Immunolocalization of integrins in the normal lung and in pulmonary carcinomas.

Cryosections of normal adult lung (n = 7) and pulmonary epithelial tumors, including squamous (n = 8), adeno (n = 8), bronchioloalveolar (n = 5), and large cell (n = 4) carcinomas (SCC, ACC, BAC, LCC), carcinoids (Cd, n = 7), and neuroendocrine carcinomas (NEC) of variable grades (n = 14) were immunostained by the avidin-biotin peroxidase (ABC) method with monoclonal antibodies to the alpha1-6 and alpha(v) and the beta1-4 integrin subunits. Normal adult alveolar septae showed variably intense immunoreactivity for alpha1,3,6 and beta1, whereas reactions for alpha5 and alpha(v) were weaker and uneven; the remaining integrin subunits were not detected. Bronchial and bronchiolar epithelium showed variably intense staining for alpha2.3,6,v and beta1,4. Reactions were often, though not invariably, basally polarized. SCC, ADC, and LCC showed variably intense reactions for alpha2.3,6,v and beta1,4. BAC were strongly and uniformly stained for alpha1.3 and beta1. In Cd, alpha1,2,3,v and beta1 reactions were noted, whereas in NEC, weak alpha1,3 and beta1 staining was detected with only traces of alpha6 and alpha(v). We conclude that alveolar epithelial cells do not express the hemidesmosome-associated, laminin-binding integrin alpha6beta4 of the bronchial epithelium but rather the alpha1beta1 and alpha3beta1, collagen IV, and laminin receptors, respectively. SCC, ADC, and sampled LCC express an integrin repertory qualitatively similar to that of the bronchial epithelium. Distinct from the latter, the integrin repertory of BAC parallels that of the alveolar epithelium by its strong expression of the multipotential alpha1beta1 and alpha3beta1 integrins. NEC tumors do not display the laminin receptors alpha6beta4 and alpha6beta1 shown by SCC and ADC but express instead alpha1beta1, a collagen IV-laminin receptor rarely found in epithelial neoplasms except for BAC. In NEC tumors, integrins, especially alpha2, decrease with dedifferentiation. Notably distinct from epithelial mesotheliomas, the major fibronectin-binding integrin alpha5beta1 was not found in any type of lung carcinoma.

Adenocarcinoma↗
PubMed1997

Pleural mesotheliomas have an integrin profile distinct from visceral carcinomas.

Cryosections of epithelial, sarcomatoid, and biphasic malignant mesotheliomas (EMM, n = 11; SMM, n = 5; BMM, n = 6) of the pleura were immunostained with monoclonal antibodies to integrin subunits alpha 1-6 and v, and beta 1-4. Localization patterns were compared with those known to occur in pulmonary and other adenocarcinomas (PADC, ADC). EMM and the epithelial component of BMM (ecBMM) expressed alpha 1,3,5,6, and v and beta 1 and 4. SMM and the sarcomatoid elements of BMM (scBMM) reacted variably for alpha 1,3,5,6 and v, and beta1. Reactions for alpha3, found in all tumors, were strongest in EMM, ecBMM, and PADC. Our findings indicate that EMM and ecBMM parallel PADC and most ADC in their expression of alpha6 beta4, underscoring that this laminin integrin receptor is intimately associated with these neoplastic epithelial phenotypes. Also, our observations on alpha3 beta1 suggest that this cell-cell adhesion-mediating integrin is related to the epithelial phenotype. Notably, all malignant mesotheliomas (MM), including those with distinct glandular structures, expressed the alpha5 beta1 fibronectin receptor, thus paralleling most sarcomas and differing from PADC and most other ADC. We conclude that irrespective of architectural and cytologic variants, transformed mesothelial cells possess an integrin repertory that differs significantly from that of most ADC, including those of the lung. These findings set mesothelium apart from epithelia and may prove helpful as adjunct tools for the differential diagnosis between EMM and AD.

Adenocarcinoma↗
PubMed1993

Immunolocalization of integrins in the normal and neoplastic colonic epithelium.

Cryosections of normal colon (NC), tubular and villous adenomas (TA, VA), and variably differentiated colon adenocarcinomas (CA) were immunostained with monoclonal antibodies to alpha 1-6 and alpha v, and beta 1-4 integrin subunits; select samples were stained for cytokeratin (Ck) 20 and villin. In NC, alpha 2 staining was strongest in crypt cells; alpha 1,3 and alpha v, and beta 1,3 and beta 4, and Ck 20 and villin predominated in superficial enterocytes. In TA and VA, monolayered glands showed integrin, Ck 20 and villin patterns that differed slightly from both crypt and superficial enterocytes. Complex glands in VA showed decreased integrin staining and basal polarization; Ck 20 and villin were strong only in luminal cells. CA showed overall weaker integrin staining than adenomas. Regardless of invasion depth, well formed malignant glands mimicked TA; pleomorphic glands mimicked VA with focal basal integrin polarization and solid clusters displayed scanty integrins, uneven Ck 20, and villin in occasional cells. Diverse integrins in crypt compared with superficial enterocytes reflect changing adhesive requirements as cells migrate and terminally differentiate. Decreasing expression and altered distribution of integrins, Ck 20 and villin noted in TA, VA, and in CA of increasing grade indicate that certain adhesive and cytoskeletal features more closely relate to glandular architecture than to depth of invasion.

Adenocarcinoma↗
PubMed1993

Distribution of tenascin, cellular fibronectins and integrins in the normal, hyperplastic and neoplastic breast.

We present immunolocalization data on tenascin (Ten), and extradomains A and B (EDA-, EDB-) and oncofetal (Onc-) isoforms of cellular fibronectin (cFn), and alpha 1-6 and alpha v and beta 1-4 integrin subunits on cryosections of normal human breast, the spectrum of fibrocystic disease (FCD), and benign and malignant breast neoplasms. Fetal breast ducts were surrounded by broad Ten bands; adult breast ducts and acini were encompassed by thin continuous rims. In FCD, Ten was detectable and was clearly enhanced around hyperplastic ducts. Fibroadenomas showed uneven Ten periductal reactions while in all carcinomas, the stroma showed extensive and strong reactions that were most intense at the tumors' invasive edge. EDA-cFn's distribution was similar to Ten's but the staining was stronger while EDB- and Onc-cFn were virtually restricted to fetal breasts and carcinomas. In the normal adult breast, alpha 1,2,3 and alpha 6, and B1 and beta 4 integrins were detected in myoepithelial cells; weaker staining was also noted in the basolateral aspect of luminal cells; this profile was retained--and at times enhanced--in FCD, fibroadenomas and in situ carcinomas in which myoepithelial elements were present. In carcinomas, particularly in those of high grade, integrins tended to be reduced. However, mucinous carcinomas showed enhanced expression and the emergence of alpha 5 integrin that was not in the normal repertory; also a subset of infiltrating lobular carcinomas showed prominent alpha 1 and alpha 6 and beta 1 and--rarely--beta 4 staining distributed in delicate cytoplasmic processes (kinetopodia). These data indicate that the complex cell-matrix and cell-cell interactions of the normal breast are slightly altered in hyperplastic processes and benign neoplasms whereas profound chances occur in carcinomas. The latter display enhanced Ten and EDA- and Onc-cFn expression in particular, while most integrins appear decreased. Notably, mucinous and some lobular carcinomas display enhancement of certain integrins. The conspicuous localization of integrins in kinetopodia may be significant in relation to the invasive behavior of lobular carcinomas.

Breast↗
PubMed1992

Integrin distributions in renal cell carcinomas of various grades of malignancy.

We studied 41 renal cell carcinomas, classified according to histologic grades G1 through G3, by indirect immunofluorescence microscopy using a panel of monoclonal antibodies (MAb) against various integrin subunits, and the basement membrane (BM) components laminin and collagen type IV. Selected cases also were immunostained using the avidin-biotin-complex method. The alpha 3 and beta 1 integrin subunits were detected in tumor cells of all the carcinomas. All G1 carcinomas, like normal tubular epithelial cells, expressed the alpha 6 subunit, whereas it was lacking in 20% and 40% of G2 and G3 carcinomas, respectively. Furthermore, when alpha 6 was expressed, a lack of basally polarized organization of the subunit, coupled with disorganization of the BM components, correlated with histologic grade. Another feature that appeared to characterize the more anaplastic tumors was their high level (80%) of the alpha v subunit expression as compared with its absence in the G1 carcinomas. Stromal myofibroblasts, identified by double-labeling with anti-myosin, were often characterized by the expression of the alpha 1, alpha 3, alpha 5 and beta 1 subunits. These results indicate that changes in integrin expression in renal cell carcinomas may be correlated with their degree of histologic malignancy.

Basement Membrane↗
PubMed1991

Relationship of the expression of the multidrug resistance gene product (P-glycoprotein) in human colon carcinoma to local tumor aggressiveness and lymph node metastasis.

P-glycoprotein mediates classic multidrug resistance by functioning as an efflux pump that excretes lipophilic chemotherapeutic drugs from cancer cells. We now report an association of P-glycoprotein in colon carcinomas with another tumor property, i.e., enhancement of local tumor aggressiveness. P-glycoprotein was detected with monoclonal antibody immunohistochemistry in 65 of 95 primary colon adenocarcinomas, which were stage B1 or greater. In all but 1 of the 95 cases, solitary invading carcinoma cells were present at the leading edge of the tumor. This subpopulation of invasive carcinoma cells expressed P-glycoprotein (P-Gp+) in 47 of the 95 surgically resected colon specimens. Cases were grouped on the basis of the presence (Group 1, 47 cases) or absence (Group 2, 48 cases) of P-Gp+ invasive carcinoma cells. There was a significantly greater incidence of vessel invasion (P less than 0.001) and lymph node metastases (P less than 0.01) in Group 1 cases. Groups 1 and 2 did not differ with respect to tumor size, depth of invasion of the bowel wall, histological grade, maximum tumor size, mitotic index, mucin production, or presence of perineural invasion (P greater than 0.1). Our findings indicate that P-Gp+ invasive colon cancer cells may have an increased potential for dissemination, suggesting that P-glycoprotein may influence cell behavior.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1991

Immunohistochemical localization of integrins in the normal, hyperplastic, and neoplastic breast. Correlations with their functions as receptors and cell adhesion molecules.

Integrins comprise a family of transmembrane glycoproteins that modulate cell-matrix and cell-cell relationships by acting as receptors to extracellular protein ligands, and also as direct adhesion molecules. The authors studied by immunohistochemistry the distribution of the alpha 1-6,v and the beta 1,3,4 subunits of integrins in samples of normal breast, the spectrum of fibrocystic disease (FCD), and representative benign and malignant neoplasms. Monoclonal antibodies (Mabs) specific for each subunit were applied to cryosections by the avidin-biotin-complex method; selected samples were studied by double immunofluorescence microscopy with the Mabs and a polyclonal antiserum to myosin. The authors found that the alpha 1-3,6,v and the beta 1, integrin subunits were detectable in the normal breast parenchyma; myoepithelial cells were consistently more prominently stained than the basolateral aspect of the luminal cells. This immunoprofile was retained, and in cases enhanced through the spectrum of FCD, in benign tumors and in ductal and lobular carcinomas in situ. In most infiltrating ductal carcinomas, integrin staining tended to decrease except for some cases that reacted strongly for the alpha v subunit. Several mucinous carcinomas reacted strongly for alpha 2,3,6,v and beta 4 subunits, and even more so for the alpha 5 subunit that was not found in the normal breast. Subsets of infiltrating lobular carcinomas stained convincingly for alpha 1,3,6,v and beta 1 subunits in delicate but abundant kinetopodia. Our findings indicate that in hyperplasias and in benign tumors integrin expression patterns parallel those of the normal breast, whereas in carcinomas, variations include decrease, enhancement, and emergence of certain subunits that are not in the normal repertory. Alterations of integrin expression parallel phenotypic changes in breast carcinoma cells; they also reflect their disrupted interaction with the similarly disrupted extracellular matrix. Enhancement of certain integrins in some carcinomas may reflect the selection of subpopulations with increased binding capacity which in turn may impact on their invasive and metastatic properties.

Antibodies, Monoclonal↗
PubMed1990

Extracellular matrix proteins and their receptors in the normal, hyperplastic and neoplastic breast.

We studied by immunohistochemistry, the distribution of tenascin (Ten), cellular fibronectin (cFn), laminin and certain pertinent extracellular matrix protein receptors in normal human female breast, variants of fibrocystic disease (FCD), benign tumors, and ductal and lobular carcinomas. Monoclonal antibodies (mAb) to Ten, extradomain A containing cFn (EDAcFn), A and B chains of laminin, and beta-1 (beta-1) and different alpha subunits of intergrins were used. In in-situ ductal and lobular carcinomas, laminin staining had focal gaps, Ten-immunoreactivity displayed periductal or periacinar bands, and cFn showed broad and intense periductal staining; strong reactions for beta-1 and alpha-6 were noted in the basal cytoplasm of non-neoplastic myoepithelial cells while few tumor cells stained weakly. In infiltrating ductal and lobular carcinomas (IDC, ILC), laminin reactivity was weak, uneven or absent around neoplastic clusters whereas stromal staining for Ten and cFn was extensive and strong. In most IDC, moderate beta-1 and alpha-6 staining involved variable subpopulations; one mucinous carcinoma stained strongly and diffusely. In 20-40% of cells in ILC, beta-1 and alpha-6 were localized in delicate, ramified cytoplasmic processes. Indirect immunofluorescence studies with mAbs to other alpha-integrin subunits suggest that in various breast carcinomas only alpha-3 is expressed in tumor cells and that the vessels contained alpha-1 integrin. As compared with the normal breast, FCD and benign tumors, reactivity for Ten and cFn is increased in breast carcinomas while laminin is attenuated and decreased or absent; yet, Ten cannot be regarded as a carcinoma marker since it can be detected in benign tumors, FCD, and even in the normal breast.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenofibroma↗
PubMed1990

Immunohistochemical analysis of pulmonary and pleural neoplasms with monoclonal antibodies B72.3 and CSLEX-1.

Sequential paraffin sections of 222 epithelial lung tumors comprising all common histologic types, and 31 pleural mesotheliomas of all variants were immunostained with monoclonal antibodies (Mabs) B72.3 and CSLEX-1. Reactivity with Mabs B72.3 and CSLEX-1 respectively was noted in 7/57 and 4/57 squamous carcinomas, in 44/70 and 60/70 adenocarcinomas, 9/16 and 11/16 bronchioloalveolar carcinomas, 8/25 and 14/25 large cell undifferentiated carcinomas, 3/3 and 3/3 adenosquamous carcinomas, 0/11 and 0/11 carcinoids, 0/10 and 2/10 well differentiated neuroendocrine (NE) carcinomas, 4/13 and 5/13 intermediate cell NE carcinomas, 0/17 and 0/17 small cell NE carcinomas, and 0/31 and 1/31 mesotheliomas. In most instances, both Mabs stained the same tumors; however, reactivity with CSLEX-1 was more intense and extensive, and involved more cases. Therefore, regardless of conventional histologic type, staining with Mabs B72.3 and CSLEX-1 defines 4 subsets of lung tumors: one expressing both antigens, two expressing one but not the other, and one expressing neither. The possible biological and/or clinical significance of these subsets remains undetermined. When correlated with conventional histologic tumor types, our findings indicate: 1). both of these Mabs recognize most but not all adenocarcinomas and bronchioloalveolar carcinomas, and since CSLEX-1 stained more cases than B72.3, it may be argued that the former is a broader exocrine phenotype marker than the latter; 2). both of these Mabs select exocrine subsets of large cell undifferentiated carcinomas; 3). both of these Mabs stain exocrine cell subpopulations in well differentiated and intermediate cell NE carcinomas but not in carcinoids or small cell NE carcinomas, and 4). except for rare cases, neither B72.3 nor CSLEX-1 reacts with mesotheliomas regardless of variant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗