RESUMEN
Three cytologically distinct cell populations were identified, in addition to ciliated cells, when a unit gravity sedimentation procedure was applied to pronase-dispersed rabbit endocervical cells. Two of these cell populations contained histochemically distinguishable (periodic acid- Schiff [PAS]) mucoproteins and were designated vacuolated and granular PAS-positive cells. The third, designated as vacuolated PAS-negative, did not contain secretory granules. Cell integrity was confirmed by trypan blue dye exclusion, [(3)H]leucine incorporation, and ultrastructural analysis. To demonstrate hormonal modulation of endocervical cell morphology, cell distribution profiles were compared from animals in different hormonal states. In the absence of estrogen dominance, PAS- positive cells from 5-d pseudopregnant rabbits were reduced 50 percent, while vacuolated PAS-negative cells increased fourfold as compared with estrous cell populations. The PAS-positive cells sedimented toward the top of the gradient where the bovine serum albumin concentrations were lower, consistent with a reduction in the number of secretory granules. In the sustained absence of ovarian steroid hormones, the number of PAS-positive mucous cells from ovariectomized rabbits was reduced to only 4 percent of the total endocervical cell population. The biosynthetic capacity of isolated endocervical cells was determined by incubating the three nonciliated cell populations from estrous and 5-d pseudopregnant rabbits for 36 h with the mucin precursor, [(14)C]N-acetyl- D-glucosamine. Only PAS-positive cells incorporated significant amounts of labeled precursor. This study indicates that steroid hormones influence cervical secretions by modulating the type of endocervical cells.
Asunto(s)
Cuello del Útero/citología , Estro , Animales , Castración , Separación Celular/métodos , Cuello del Útero/metabolismo , Estrógenos/fisiología , Femenino , Glicoproteínas/metabolismo , Microscopía Electrónica , Mucinas/biosíntesis , Embarazo , Progesterona/fisiología , Seudoembarazo , Conejos , Vacuolas/ultraestructuraRESUMEN
The mucociliary urn cell complex of the marine coelomate Sipunculus nudus secretes mucus 4 to 5 minutes after being exposed to Lotus tetragonolobus and Ricinus communis I agglutinins. Surface binding of both lectins is confined to the secretory area of the urn cell complex and, like the release of mucus, is inhibited by the specific saccharides L-fucose and D-galactose or by incubation in L-fucosidase and D-galactosidase. Mucus secretion may therefore be initiated by the interaction of mucus-releasing stimuli with fucosyl or galactosyl residues of specific membrane receptors.
RESUMEN
Farnesyltransferase inhibitors (FTIs) represent a novel class of anticancer drugs that exhibit a remarkable ability to inhibit malignant transformation without toxicity to normal cells. However, the mechanism by which FTIs inhibit tumor growth is not well understood. Here, we demonstrate that FTI-277 inhibits phosphatidylinositol 3-OH kinase (PI 3-kinase)/AKT2-mediated growth factor- and adhesion-dependent survival pathways and induces apoptosis in human cancer cells that overexpress AKT2. Furthermore, overexpression of AKT2, but not oncogenic H-Ras, sensitizes NIH 3T3 cells to FTI-277, and a high serum level prevents FTI-277-induced apoptosis in H-Ras- but not AKT2-transformed NIH 3T3 cells. A constitutively active form of AKT2 rescues human cancer cells from FTI-277-induced apoptosis. FTI-277 inhibits insulin-like growth factor 1-induced PI 3-kinase and AKT2 activation and subsequent phosphorylation of the proapoptotic protein BAD. Integrin-dependent activation of AKT2 is also blocked by FTI-277. Thus, a mechanism for FTI inhibition of human tumor growth is by inducing apoptosis through inhibition of PI 3-kinase/AKT2-mediated cell survival and adhesion pathway.
Asunto(s)
Transferasas Alquil y Aril/antagonistas & inhibidores , Transferasas Alquil y Aril/metabolismo , Apoptosis , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas , Proteínas Proto-Oncogénicas/metabolismo , Transducción de Señal , Apoptosis/efectos de los fármacos , Línea Celular , Inhibidores Enzimáticos/farmacología , Farnesiltransferasa , Femenino , Humanos , Metionina/análogos & derivados , Metionina/farmacología , Proteínas Tirosina Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt , Transducción de Señal/efectos de los fármacosRESUMEN
Cell proliferation and papillogenesis are growth factor-sensitive events in the ovarian mesothelium, the tissue source of ovarian epithelial cancer. To further investigate the regulation of cell proliferation in this tissue, rabbit ovarian mesothelial cells (OMC) were transfected in vitro with a CVN expression vector carrying the human gene for insulin-like growth factor 1 receptor (IGF-1R). The growth characteristics of IGF-1R transfectants (OMIR) and their response to IGF-1 were then compared with those of OMC in serumless HL-1 cultures. OMIR cells formed epithelial-like colonies and, even when nonconfluent, produced tridimensional structures reminiscent of papillae seen in ovarian serous epithelial tumors. After 3 and 7 days of exposure to IGF-1, OMIR cells grew approximately 20-fold (P < 0.05), and papillogenesis was 15- to 25-fold over similar events in OMC, respectively. Exposure to treatment with antisense oligonucleotides against IGF-1R mRNA inhibited OMIR growth rate by 70%. Western immunoblotting and flow cytometry revealed higher expression of IGF-1R in OMIR cells than in OMC. The reverse was true when Fas-receptor expression was evaluated. OMIR cells were clonogenic in 15% serum-rich soft agar assay (OMIR:OMC colony-forming ratio 150-200:1), and tumorigenic in nude mice in which high-grade carcinomas with occasional lung metastases were observed. These data suggest that IGF-1R plays a role in ovarian epithelial carcinogenesis. The overexpression of this receptor induces transformation and morphogenesis of OMCs via an autocrine mechanism. IGF-1R may down-regulate the Fas expression rendering transformed ovarian mesothelial cells resistant to apoptosis.
Asunto(s)
Transformación Celular Neoplásica , Células Epiteliales/citología , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Ovario/citología , Papiloma/genética , Receptor IGF Tipo 1/fisiología , Animales , División Celular/efectos de los fármacos , Células Epiteliales/fisiología , Femenino , Fibronectinas/fisiología , Humanos , Ratones , Ratones Desnudos , Oligodesoxirribonucleótidos Antisentido/farmacología , Papiloma/patología , ARN Mensajero/antagonistas & inhibidores , ARN Mensajero/genética , Conejos , Receptor IGF Tipo 1/genética , Receptores del Factor de Necrosis Tumoral/genética , Proteínas Recombinantes/metabolismo , Transfección , Trasplante Heterólogo , Ensayo de Tumor de Célula Madre , Receptor fasRESUMEN
Three members have been identified in the protein kinase B (PKB) family, i.e., Akt/PKB alpha, AKT2/PKB beta, and AKT3/PKB gamma. Previous studies have demonstrated that only AKT2 is predominantly involved in human malignancies and has oncogenic activity. However, the mechanism of transforming activity of AKT2 is still not well understood. Here, we demonstrate the activation of AKT2 with several growth factors, including epidermal growth factor, insulin-like growth factor 1, insulin-like growth factor II, basic fibroblast growth factor, platelet-derived growth factor, and insulin, in human ovarian epithelial cancer cells. The kinase activity and the phosphorylation of AKT2 were induced by the growth factors and blocked by the phosphatidylinositol (PI) 3-kinase inhibitor, wortmannin, and dominant-negative Ras (N17Ras). Moreover, the activated Ras and v-Src, two proteins that transduce growth factor-generated signals, also activated AKT2, and this activation was not significantly enhanced by growth factor stimulation but was abrogated by wortmannin. These results indicate that AKT2 is a downstream target of PI 3-kinase and that Ras and Src function upstream of PI 3-kinase and mediate the activation of AKT2 by growth factors. The findings also provide further evidence that AKT2, in cooperation with Ras and Src, is important in the development of some human malignancies.
Asunto(s)
Genes ras/fisiología , Proteína Oncogénica pp60(v-src)/metabolismo , Proteínas Oncogénicas/metabolismo , Neoplasias Ováricas/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Activación Enzimática , Femenino , Humanos , Neoplasias Ováricas/enzimología , Fosforilación , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-akt , Células Tumorales CultivadasRESUMEN
We have shown previously that the AKT2 pathway is essential for cell survival and important in malignant transformation. In this study, we demonstrate elevated kinase levels of AKT2 and phosphatidylinositol-3-OH kinase (PI3K) in 32 of 80 primary breast carcinomas. The majority of the cases with the activation are estrogen receptor alpha (ERalpha) positive, which prompted us to examine whether AKT2 regulates ERalpha activity. We found that constitutively activated AKT2 or AKT2 activated by epidermal growth factor or insulin-like growth factor-1 promotes the transcriptional activity of ERalpha. This effect occurred in the absence or presence of estrogen. Activated AKT2 phosphorylates ERalpha in vitro and in vivo, but it does not phosphorylate a mutant ERalpha in which ser-167 was replaced by Ala. The PI3K inhibitor, wortmannin, abolishes both the phosphorylation and transcriptional activity of ERalpha induced by AKT2. However, AKT2-induced ERalpha activity was not inhibited by tamoxifen but was completely abolished by ICI 164,384, implicating that AKT2-activated ERalpha contributes to tamoxifen resistance. Moreover, we found that ERalpha binds to the p85alpha regulatory subunit of PI3K in the absence or presence of estradiol in epithelial cells and subsequently activates PI3K/AKT2, suggesting ERalpha regulation of PI3K/AKT2 through a nontranscriptional and ligand-independent mechanism. These data indicate that regulation between the ERalpha and PI3K/AKT2 pathway (ERalpha-PI3K/AKT2-ERalpha) may play an important role in pathogenesis of human breast cancer and could contribute to ligand-independent breast cancer cell growth.
Asunto(s)
Neoplasias de la Mama/enzimología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas , Proteínas Proto-Oncogénicas/metabolismo , Receptores de Estrógenos/metabolismo , Androstadienos/farmacología , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Células COS , Activación Enzimática , Inducción Enzimática , Inhibidores Enzimáticos/farmacología , Células Epiteliales/enzimología , Células Epiteliales/metabolismo , Antagonistas de Estrógenos/farmacología , Receptor alfa de Estrógeno , Genes Reporteros , Humanos , Fosfatidilinositol 3-Quinasas/biosíntesis , Inhibidores de las Quinasa Fosfoinosítidos-3 , Fosforilación , Proteínas Proto-Oncogénicas/biosíntesis , Proteínas Proto-Oncogénicas c-akt , Receptores de Estrógenos/antagonistas & inhibidores , Receptores de Estrógenos/fisiología , Tamoxifeno/farmacología , Transcripción Genética/fisiología , Transfección , WortmaninaRESUMEN
Upregulation of the cyclin-dependent kinase inhibitor p21WAF1/CIP1 and subsequent cell growth arrest or senescence is one mechanism by which normal cells are believed to respond to stress induced by the constitutively activated GTPase Ras. We hypothesize that in the absence of p21, the onset of Ras-dependent oncogenesis is accelerated. To test this hypothesis, we crossed MMTV/v-Ha-ras transgenic mice into a p21-deficient background. By 63 days of age, all 8 ras/p21-/- mice developed either malignant (mammary and/or salivary adenocarcinomas) or benign (Harderian hyperplasia) tumors. In contrast, by the same age, only one out of nine of the ras/p21+/+ mice developed a tumor. Furthermore, by 94 days of age, half of the ras/p21-/- mice, but none of the ras/p21+/+ mice, developed mammary tumors. p21-deficiency also accelerated the development of salivary (T50=66 days for ras/p21-/- vs T50=136 days for ras/p21+/+) and Harderian (T50=52 days for ras/p21-/- vs T50>221 days for ras/p21+/+) tumors. Furthermore, two out of the eight ras/p21-/- mice had metastatic lesions, one in its lungs, the other in its abdomen. None of the nine ras/p21+/+ mice had metastatic lesions. By 4 months of age, the mammary tumor multiplicity was 10-fold greater in ras/p21-/- (average 3.40 tumors/mouse) than in ras/p21+/+ (average 0.33 tumor/mouse) mice. However, once the tumors appeared, their growth rate, apoptosis level, and mitotic index were not affected by the loss of p21, suggesting that loss of p21 is critical in early but not late events of Ras oncogenesis. Altogether, the results show that tumor onset in MMTV/v-Ha-ras mice is p21-dependent with loss of p21 associated with earlier tumor appearance and increased tumor multiplicity and aggressiveness.
Asunto(s)
Carcinoma Ductal de Mama/fisiopatología , Ciclinas/fisiología , Genes ras/fisiología , Neoplasias Mamarias Animales/fisiopatología , Proteína Oncogénica p21(ras)/fisiología , Adenocarcinoma/etiología , Adenocarcinoma/genética , Adenocarcinoma/patología , Adenocarcinoma/fisiopatología , Animales , Carcinoma Ductal de Mama/etiología , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/patología , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Ciclinas/genética , Modelos Animales de Enfermedad , Femenino , Expresión Génica , Masculino , Neoplasias Mamarias Animales/etiología , Neoplasias Mamarias Animales/genética , Neoplasias Mamarias Animales/patología , Ratones , Ratones Noqueados , Ratones Transgénicos , Proteína Oncogénica p21(ras)/genética , Neoplasias de las Glándulas Salivales/etiología , Neoplasias de las Glándulas Salivales/genética , Neoplasias de las Glándulas Salivales/patología , Neoplasias de las Glándulas Salivales/fisiopatologíaRESUMEN
We previously demonstrated that AKT2, a member of protein kinase B family, is activated by a number of growth factors via Ras and PI 3-kinase signaling pathways. Here, we report the frequent activation of AKT2 in human primary ovarian cancer and induction of apoptosis by inhibition of phosphoinositide-3-OH kinase (PI 3-kinase)/Akt pathway. In vitro AKT2 kinase assay analyses in 91 ovarian cancer specimens revealed elevated levels of AKT2 activity (>3-fold) in 33 cases (36.3%). The majority of tumors displaying activated AKT2 were high grade and stages III and IV. Immunostaining and Western blot analyses using a phospho-ser-473 Akt antibody that detects the activated form of AKT2 (AKT2 phosphorylated at serine-474) confirmed the frequent activation of AKT2 in ovarian cancer specimens. Phosphorylated AKT2 in tumor specimens localized to the cell membrane and cytoplasm but not the nucleus. To address the mechanism of AKT2 activation, we measured in vitro PI 3-kinase activity in 43 ovarian cancer specimens, including the 33 cases displaying elevated AKT2 activation. High levels of PI 3-kinase activity were observed in 20 cases, 15 of which also exhibited AKT2 activation. The remaining five cases displayed elevated AKT1 activation. Among the cases with elevated AKT2, but not PI 3-kinase activity (18 cases), three showed down-regulation of PTEN protein expression. Inhibition of PI 3-kinase/AKT2 by wortmannin or LY294002 induces apoptosis in ovarian cancer cells exhibiting activation of the PI 3-kinase/AKT2 pathway. These findings demonstrate for the first time that activation of AKT2 is a common occurrence in human ovarian cancer and that PI 3-kinase/Akt pathway may be an important target for ovarian cancer intervention.
Asunto(s)
Apoptosis/fisiología , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/patología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Supresoras de Tumor , Adenocarcinoma Mucinoso/metabolismo , Adenocarcinoma Mucinoso/patología , Adenocarcinoma Papilar/metabolismo , Adenocarcinoma Papilar/patología , Adenosarcoma/metabolismo , Adenosarcoma/patología , Secuencia de Aminoácidos , Western Blotting , Cromonas/farmacología , Secuencia Conservada , Cistadenocarcinoma/metabolismo , Cistadenocarcinoma/patología , Femenino , Fibroma/metabolismo , Fibroma/patología , Histonas/metabolismo , Humanos , Datos de Secuencia Molecular , Morfolinas/farmacología , Proteínas Oncogénicas/metabolismo , Fosfohidrolasa PTEN , Inhibidores de las Quinasa Fosfoinosítidos-3 , Monoéster Fosfórico Hidrolasas/metabolismo , Fosforilación , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas/inmunología , Proteínas Proto-Oncogénicas c-akt , Neoplasia Tecoma/metabolismo , Neoplasia Tecoma/patologíaRESUMEN
Ovarian cancer is a richly vascularized neoplasm with solid and cystic components. The purpose of this study was to determine whether cyst fluid could be used to quantitatively evaluate production of angiogenic factors in ovarian lesions. ELISA was used to measure vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in the cyst fluid of patients with ovarian cancer (n = 13), benign cysts and cystadenomas (n = 23), borderline tumors (n = 5), and functional cysts (n = 8). VEGF levels were markedly elevated in the fluid of malignant cysts (38.5+/-8.2 ng/ml) as compared with benign (1.6+/-0.4 ng/ml; P < 0.001), borderline (5.7+/-1.5 ng/ml; P < 0.001), or functional cysts (3.8+/-2.0 ng/ml; P < 0.001). The presence of VEGF in cancer cells was confirmed by immunohistochemistry. Follow-up of patients with malignant and borderline lesions demonstrated a correlation between VEGF levels in cyst fluid and tumor recurrence (P = 0.03). bFGF in malignant cysts was either undetectable or very low (0.3+/-0.2 ng/ml), and no significant differences were found in bFGF levels among malignant, benign, borderline, and functional cysts. This study demonstrates that ovarian malignancy is associated with dramatic elevation of VEGF levels in ovarian cyst fluid. Conversely, there is no correlation between cyst fluid bFGF levels and malignant transformation. The high levels of VEGF in malignant cysts are consistent with the hypothesis that this growth factor plays an important role in ovarian cancer related-angiogenesis and tumor progression and represents a potentially important target of antiangiogenic therapy.
Asunto(s)
Líquido Quístico/metabolismo , Factores de Crecimiento Endotelial/metabolismo , Linfocinas/metabolismo , Quistes Ováricos/metabolismo , Neoplasias Ováricas/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/metabolismo , Cistoadenoma/metabolismo , Ensayo de Inmunoadsorción Enzimática , Femenino , Factor 2 de Crecimiento de Fibroblastos/metabolismo , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico , Neoplasias Ováricas/diagnóstico , Valor Predictivo de las Pruebas , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial VascularRESUMEN
Estrogens are mitogens that stimulate the growth of both normal and transformed epithelial cells of the female reproductive system. The effect of estrogens is mediated through the estrogen receptors, which are ligand-regulated transcription factors. Tamoxifen, a selective estrogen receptor modulator, functions as an estrogen receptor antagonist in breast but an agonist in uterus. In the current study, we show that coexpression of a constitutively active MEKK1, but not RAF or MEKK2, significantly increases the transcriptional activity of the receptor in endometrial and ovarian cancer cells. The expression of wild-type MEKK1 and an active Rac1, which functions upstream of MEKK1, also increased the activity of the receptor while coexpression of dominant negative MEKK1 blocked the Rac1 induction, indicating that endogenous MEKK1 is capable of activating the receptor. Additional experiments demonstrated that the MEKK1-induced activation was mediated through both Jun N-terminal kinases and p38/Hog1 and was independent of the known phosphorylation sites on the receptor. p38, but not Jun N-terminal kinases, efficiently phosphorylated the receptor in immunocomplex kinase assays, suggesting a differential involvement of the two kinases in the receptor activation. More importantly, the expression of the constitutively active MEKK1 increased the agonistic activity of 4-hydroxytamoxifen to a level comparable to that of 17beta-estradiol and fully blocked its antagonistic activity. These findings suggest that the uterine-specific agonistic activity of the tamoxifen compound may be determined by the status of kinases acting downstream of MEKK1.
Asunto(s)
Neoplasias Endometriales/tratamiento farmacológico , Antagonistas de Estrógenos/farmacología , Quinasa 1 de Quinasa de Quinasa MAP , Neoplasias Ováricas/tratamiento farmacológico , Proteínas Serina-Treonina Quinasas/metabolismo , Receptores de Estrógenos/metabolismo , Tamoxifeno/análogos & derivados , Neoplasias Endometriales/metabolismo , Activación Enzimática , Inhibidores Enzimáticos/farmacología , Receptor alfa de Estrógeno , Femenino , Flavonoides/farmacología , Humanos , Imidazoles/farmacología , Proteínas Quinasas JNK Activadas por Mitógenos , MAP Quinasa Quinasa Quinasa 2 , Quinasas Quinasa Quinasa PAM/efectos de los fármacos , Quinasas Quinasa Quinasa PAM/genética , Quinasas Quinasa Quinasa PAM/metabolismo , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Neoplasias Ováricas/metabolismo , Fosforilación , Proteínas Serina-Treonina Quinasas/genética , Proteínas Proto-Oncogénicas c-raf/efectos de los fármacos , Proteínas Proto-Oncogénicas c-raf/genética , Proteínas Proto-Oncogénicas c-raf/metabolismo , Piridinas/farmacología , Receptores de Estrógenos/efectos de los fármacos , Receptores de Estrógenos/genética , Tamoxifeno/farmacología , Transcripción Genética , Células Tumorales Cultivadas , Proteínas Quinasas p38 Activadas por MitógenosRESUMEN
Immunohistochemical expression of p53, Bc12, vimentin, and S100 protein-positive Langerhans cell was evaluated in 50 endometrial carcinomas (6 stage I, 14 stage II, 20 stage III, and 10 stage IV), in an attempt to use these markers as predictors of survival. Monoclonal antibodies to p53, Bcl-2, vimentin, and S100 proteins were applied to paraffin-embedded sections of endometrial adenocarcinoma, using the avidin-biotin peroxidase complex technique (ABC). All 20 patients with stage I and II carcinomas were alive with a mean follow-up of 3 years. Of 30 patients with stage III and IV carcinomas, 13 died of tumor (3-year survival, 57%; SE, 10%), eight were alive with tumor, and nine were alive with no evidence of tumor (mean follow-up, 46 months). Strong p53 positivity was present in 11 carcinomas (22%), including nine high-stage and two low-stage tumors. Bcl-2 positivity was identified in 33 tumors (66%). These tumors were mostly low stage; however, no correlation was found between Bcl-2 expression and prognosis. Vimentin positivity (P < .001), and tumor infiltration by a large number of S100 protein-positive Langerhans cells (P < .05) were associated with low-stage tumors. Vimentin was expressed in 23 carcinomas, including 70% of low-stage tumors and 20% of high-stage tumors. Most high-grade carcinomas were Langerhans cell depleted; most low-grade carcinomas showed >50 S100 protein-positive Langerhans cells/10 high-power fields. Our results indicate that Langerhans cell infiltration and vimentin positivity of tumor cells are favorable prognostic factors in endometrial carcinomas.
Asunto(s)
Adenocarcinoma/metabolismo , Neoplasias Endometriales/metabolismo , Células de Langerhans/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas S100/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Vimentina/metabolismo , Adenocarcinoma/patología , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor , Neoplasias Endometriales/patología , Femenino , Humanos , Inmunohistoquímica , Células de Langerhans/patología , Persona de Mediana Edad , Proteínas de Neoplasias/metabolismo , Estadificación de Neoplasias , PronósticoRESUMEN
The activation of the insulinlike growth factor 1/IGF-1 receptor system (IGF1/IGF1-R) has recently emerged as critical event in transformation and tumorigenicity of several murine and human tumors. Expression of IGF1 and of IGF1-R has been demonstrated in normal and neoplastic intestinal cell lines of rats and humans. However, the modulation of IGF1-R expression during the progression from normal colonic mucosa to adenoma, to carcinoma, and to metastasis, has not been evaluated. In this retrospective study, we investigated the expression of IGF1-R in 12 colonic adenomas (AD), 36 primary colorectal adenocarcinomas (CA), and in 27 corresponding metastases (MT). Normal colonic mucosa (N) was adjacent to the CA in 34 cases. Formalin-fixed, paraffin-embedded tissues of each case were immunostained using the avidin-biotin-peroxidase method. We used an anti-IGF1-R rabbit polyclonal antibody (Santa Cruz Biotechnology, CA; dilution 1:100). Positive staining was quantitated by CAS-200. Moderate to strong cytoplasmic immunostaining was observed in 34 of 36 CA (96%), and in 25 of 27 MT (93%). In all of the positive MTs, the intensity of the staining was always strong. In 10 of 12 ADs (83%), only a faint cytoplasmic stain was identified. Normal mucosa when present was negative. Strong IGF1-R positivity correlated with higher grade and higher-stage tumors (P < .01). These data suggest a role of IGF1-R expression during the progression of colorectal adenoma to carcinoma. An increased number of IGF1-R receptors may favor the metastasis of colorectal cancer.
Asunto(s)
Adenocarcinoma/metabolismo , Neoplasias Colorrectales/metabolismo , Receptor IGF Tipo 1/biosíntesis , Adenoma/metabolismo , Anciano , Anciano de 80 o más Años , Colon/metabolismo , Femenino , Humanos , Inmunohistoquímica , Mucosa Intestinal/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/secundario , Ganglios Linfáticos/metabolismo , Metástasis Linfática , MasculinoRESUMEN
CD44 is an adhesion molecule involved in cell-to-cell and cell-to-matrix interactions. This transmembrane glycoprotein exists in either standard or variant forms, originated by alternative splicing. One of the isoforms (CD44V6) has been shown, in some systems, to modify the metastatic potential of tumor cells. To investigate the role of this biomarker as possible prognostic antigen in colorectal cancer, we immunohistochemically analyzed the distribution of CD44V6 expression on formalin-fixed, paraffin-embedded tissues from resected colorectal cancers of 34 patients. The monoclonal antibody VFF7 against the amino acid sequence encoded by exon CD44V6 was applied using the avidin-biotin-peroxidase method. For each resected specimen, normal (N), adenomatous (AD), and carcinomatous (CA) colonic mucosa were tested. In 68% of the resected cases, these areas were present in the same slide, and in 76% of cases, nodal or liver metastases (MT) were available for evaluation. Adenomatous polyp biopsy specimens of 10 carcinoma-free patients were also tested. In selected cases, CD44V6 expression was also determined using the Western blot immunoprecipitation technique. CD44V6 immunoreactivity was detected in 100% of the ADs, and in 91% of CAs, but was mostly weak in only 38% of MTs (n=26). In 49% (n=35) of ADs, 11% (n=34) of CAs, and 4% of MTs (n=26), the stain was moderate to strong. CD44V6 immunoreactivity was predominantly membranous in ADs and cytoplasmic in MTs. In the CAs, both staining patterns were noted. Interestingly, the normal mucosa had a weak subnuclear localization of the stain. In the cases evaluated by Western blotting immunoprecipitation analysis, the level of CD44V6 protein expression was similar to that obtained by immunohistochemistry. No correlation was found with tumor type, stage, or patient survival. The predominant CD44V6 expression in ADs and CAs, but not in MTs, suggests that, in many cases, the expression of this adhesion molecule may be lost during the acquisition of migratory function by the tumor cells.
Asunto(s)
Adenocarcinoma/metabolismo , Adenoma/metabolismo , Antígenos de Neoplasias/metabolismo , Neoplasias Colorrectales/metabolismo , Receptores de Hialuranos/metabolismo , Adenocarcinoma/mortalidad , Adenocarcinoma/patología , Adenoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor , Western Blotting , Colon/metabolismo , Colon/patología , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Femenino , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/secundario , Metástasis Linfática/patología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Tasa de SupervivenciaRESUMEN
Loss of p53 and p21WAF1 expression have previously been reported in pancreatic adenocarcinoma. Despite these findings in several reports of oncogene and tumor suppressor gene alterations in pancreatic cancer, the clinical significance of these changes is still poorly understood. In an attempt to detect molecular prognostic markers for pancreatic carcinoma, we studied the immunohistochemical expression of p53, p21WAF1, and TGF-beta1 proteins in 42 pancreatic adenocarcinomas of the ductal type. The results were correlated with clinicopathologic findings to identify the markers with prognostic significance. p53 nuclear immunoreactivity was seen in 20 (48%) of the cases, and it was strong to moderate in 14 (33%) of them. p21WAF1 cytoplasmic positivity was found in 16 (38%) of the tumors, with 72% staining strong to moderate. TGF-beta1 stained the cytoplasm of the tumor cells in 13 (31%). Of the p53-negative cases, 12 (54%) exhibited p21WAF1 expression. In 3 (30%) of cases, TGF-beta1 reactivity was seen in the absence of p53 and p21WAF1 p53 positivity identified tumors of higher grade, but did not correlate with stage or survival. TGF-beta1 expression, however, identified low-grade tumors and patients with longer survival. No correlation was found between the expression of any of these molecular markers and smoking history. We report a significant correlation between TGF-beta1 reactivity and low-grade tumors and between TGF-beta1 and better survival. This is a novel finding pointing to TGF-beta1 as a possible new stage-independent predictor of tumor survival in pancreatic ductal adenocarcinoma. In agreement with others, we also found p53 mutation in 20 (48%) of the tumors.
Asunto(s)
Carcinoma Ductal de Mama/metabolismo , Ciclinas/metabolismo , Neoplasias Pancreáticas/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Adulto , Anciano , Biomarcadores de Tumor , Carcinoma Ductal de Mama/mortalidad , Carcinoma Ductal de Mama/patología , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Femenino , Humanos , Técnicas para Inmunoenzimas , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias Pancreáticas/mortalidad , Neoplasias Pancreáticas/patología , Pronóstico , Tasa de SupervivenciaRESUMEN
Residual microscopic disease after lumpectomy for breast cancer may cause significant local recurrence. We evaluated one hundred fourteen consecutive breast lumpectomy margins in this study by touch preparation cytology. Cytologic preparations were intraoperatively correlated with gross and frozen section results and subsequently with permanent histologic sections of representative margins. Three specimens were cytologically unsatisfactory and 86 yielded benign findings, while material suggestive or diagnostic of malignancy was obtained from 25 specimens. Gross, frozen section, and permanent histologic margins were positive in 10, 17, and 22 cases, respectively. There were three false-positive touch preparation cytologic results, while frozen section specimens were false-negative in five cases. Sensitivity and specificity of touch preparation cytology were 100% and 96.6%, respectively, with a diagnostic accuracy of 97.3%. Touch preparation cytologic examination rapidly and reliably evaluates lumpectomy margins and overcomes sampling errors and artifacts related to frozen section evaluation. This technique currently complements frozen section evaluation of lumpectomy margins as part of a protocol aimed at reducing local recurrence of breast cancer.
Asunto(s)
Neoplasias de la Mama/patología , Técnicas Citológicas , Mastectomía Segmentaria , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/cirugía , Protocolos Clínicos , Reacciones Falso Positivas , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia/prevención & control , Estudios Prospectivos , Sensibilidad y EspecificidadRESUMEN
OBJECTIVES: To evaluate the relationship of DNA ploidy and cell proliferation (CP) with Gleason score (GS) and clinical outcome in prostate cancer. METHODS: Sixteen patients with benign prostatic hyperplasia (BPH) and 65 patients with prostate cancer classified by GS (four groups: 2 to 4, 5 to 6, 7, and 8 to 10) were studied. All patients with carcinoma underwent prostatectomy and were separated into prostate-specific antigen (PSA) failure and nonfailure groups (failure if PSA 0.1 ng/mL or more three times after surgery). Tumoral CP (Ki-67 inmunostaining and SG2M phase) and DNA ploidy were evaluated by computerized cytometry. RESULTS: BPH were diploid with low CP (8% SG2M cells or less). Carcinomas were either diploid with high CP (greater than 8% SG2M cells) or aneuploid. CP was significantly higher (P <0.001) in tumors with GS 7 or greater than in tumors with GS less than 7 (mean percent Ki-67 cells 18.3% versus 7.8%, respectively). PSA failure increased with GS (7.1% in GS 2 to 4, 21% in GS 5 to 6, 28.6% in GS 7, and 50% in GS 8 to 10), as well as with aneuploidy (18.5% in diploid tumors versus 72.7% in aneuploid tumors). Those experiencing PSA failure had significantly higher (P <0.001) CP than those not failing (mean percent Ki-67 cells 24% and mean percent SG2M 30.4% versus 8.7% and 13.5%, respectively). Cox regression analysis showed GS, DNA ploidy, Ki-67, and SG2M to each be univariately prognostic for time to PSA failure; however, Ki-67 and SG2M were more highly significant (P <0.0001 for both) than GS (P = 0.007) or DNA ploidy (P = 0.002). After adjusting for either SG2M or Ki-67 measures of CP, neither ploidy nor GS contained additional prognostic value. CONCLUSIONS: Tumor CP and DNA ploidy can be reliably determined in prostate cancer by computerized cytometry. On the basis of our preliminary results, CP correlates well with GS and predicts PSA failure better than DNA ploidy or GS.
Asunto(s)
Ploidias , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/patología , Anciano , División Celular , Diagnóstico por Computador , Humanos , Masculino , Persona de Mediana Edad , Hiperplasia Prostática/sangre , Hiperplasia Prostática/genética , Hiperplasia Prostática/patología , Neoplasias de la Próstata/genética , Insuficiencia del TratamientoRESUMEN
Although most common, malignant lymphoma and Kaposi's sarcoma are not the only malignancies encountered in lymph nodes from HIV-infected patients. An increased frequency of testicular germ cell tumors in HIV-infected individuals has been reported. We report here the first case, to our knowledge, of a metastatic seminoma in an HIV-infected hemophiliac. The atypical clinical presentation, cervical and axillary adenopathy, simulated malignant lymphoma. The diagnosis was first suspected when a fine needle aspiration biopsy from an enlarged cervical node revealed a mixture of benign appearing lymphocytes and loosely cohesive large tumor cells in a "tigroid" background. Immunocytochemistry and a subsequent excisional biopsy confirmed the cytologic diagnosis. Metastatic germ cell tumors should be considered in the differential diagnosis of HIV-related lymphadenopathy.
Asunto(s)
Hemofilia A/complicaciones , Linfoma Relacionado con SIDA/diagnóstico , Seminoma/diagnóstico , Adulto , Citodiagnóstico , Diagnóstico Diferencial , Humanos , Masculino , Inducción de Remisión/métodos , Seminoma/radioterapia , Seminoma/secundarioRESUMEN
The steroidogenic activity of cumulus oophorus granulosa cells obtained from unstimulated rabbits in estrus has been investigated at closely timed intervals in short-term cultures. The presence of viable, structurally well preserved oocytes and the addition of large follicle follicular fluid had no apparent inhibitory effect on progesterone or estrogen synthesis and secretion. Progesterone secretion was especially stimulated by the addition of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) to the culture medium. A similar increment was also seen, although inconsistently, for estrogen secretion. Ultrastructural evidence of luteinization was demonstrated by quantitative morphometric techniques in control cultures as early as 6 hours after explantation and was shown to relate well to biochemical luteinization. It is suggested that the main modifications in cytoplasmic organelles concomitant with luteinization may be represented only by volume and surface changes rather than by alterations in morphology. Therefore, such changes need to be assessed quantitatively. Oocytes exhibited isolated maturative changes almost exclusively in FSH-LH cultures, such as cortical granule synthesis, resumption of meiosis, polar body extrusion, and two-cell parthenogenetic cleavage. It is suggested that cumulus granulosa cells may play a significant role in the resumption of "spontaneous" maturation in oocytes after their release in vitro from their follicles. Characteristic, thin-walled vesicles, either isolated or in rosette-like formation with cumulus granulosa cells, were described. A possible common nature was suggested for these vesicles and the so-called "Call-Exner bodies."
Asunto(s)
Cuerpo Lúteo/ultraestructura , Técnicas de Cultivo , Células de la Granulosa/ultraestructura , Folículo Ovárico/ultraestructura , Esteroides/biosíntesis , Animales , Medios de Cultivo , Células Epiteliales , Epitelio/ultraestructura , Estrógenos/biosíntesis , Estrógenos/sangre , Estrógenos/metabolismo , Estro , Femenino , Hormona Folículo Estimulante , Aparato de Golgi/ultraestructura , Células de la Granulosa/metabolismo , Hormona Luteinizante , Microscopía Electrónica , Oocitos/ultraestructura , Folículo Ovárico/análisis , Embarazo , Progesterona/biosíntesis , Progesterona/sangre , Progesterona/metabolismo , ConejosRESUMEN
The manner in which estrogens mediate cyclical changes in the viscoelastic properties and volume of cervical mucus is unclear. To identify the response to estrogens of each of the major mucus components (mucin[s], soluble proteins, and small electrolytes and water), the authors quantitated their accumulation rates before and during estrogen stimulation in the rabbit. Circulating radiolabeled markers (35S-sulfate and 131I-albumin) were used to monitor the incorporation of small and large molecular weight intravascular substances into the cervical mucus. The accumulation rate of mucins was unaffected by exogenous estrogen administration, despite significant increases in mucus volume. This increase in mucus volume was attributed to a significantly increased transudation of water and small electrolytes increasing mucus hydration as early as the first 2 hours of estrogen administration. Water, small electrolytes, and soluble proteins significantly increased during the third and fourth hours of estrogen administration, not only when compared with the unstimulated basal levels, but also when compared with the levels found during the first 2 hours of estrogen administration. No significant change occurred in mucin production, while significant changes occurred in the accumulation of proteins and small electrolytes, whether estrogen was given initially or terminally in the experiment protocol.