TIMP4 Modulates ER-α Signalling in MCF7 Breast Cancer Cells

Tissue inhibitor of metalloprotease 4 (TIMP4) contributes to poor prognosis in breast and other tumours. However, the mechanisms of how TIMP4 influences breast cancer cell behaviour are unknown. Our aim was to explore the signalling pathways modulated by TIMP4 in breast cancer cells. Human recombinant TIMP4 was added to MCF7 breast cancer cells and RNASeq was performed. TIMP4 RNASeq results were validated by RT-PCR. Network analyses of TIMP4-exposed cells showed that ER-α, HIF1A and TGF-β signalling were activated, whereas FOXO3 signalling was downregulated. ER-α protein levels were increased and concordantly, promoters of TIMP4-upregulated genes were significantly enriched in oestrogen-binding sites. We concluded that TIMP4 modulates multiple signalling pathways relevant in cancer in MCF7 cells, including the ER-α cascade.

NF-kappa B is required for the development of tumor spheroids

Tumor cells cultured in three-dimensional models provide a more realistic and biologically meaningful analysis of the initial phases of cancer development and drug resistance. Several studies have demonstrated that culture of cancer cells in three dimensions induces cellular resistance to a variety of anti-neoplastic drugs by poorly understood mechanisms. The role of the transcription factor NF-kappaB and inhibitors of apoptosis proteins (IAPs) in the onset and development of drug resistance during tumor spheroid growth has not been established. In this work, we found a significant increase in the activity and expression of NF-kappaB and its downstream target XIAP (X-linked IAP) in cancer cells grown as multi-cellular tumor spheroids. Blocking XIAP expression with RNA interference markedly increased the sensitivity of cancer tumor spheroid cells toward anti-neoplastic drugs, indicating a role for IAPs in establishing drug resistance. In turn, inhibition of NF-kappaB by negative dominants suppressed spheroid formation, whereas overexpression of the upstream kinase IkappaBKbeta increased their growth and resistance. The present data suggested that NF-kappaB and its downstream target XIAP were essential for the growth and drug resistance of small avascular tumor.

Gene regulation by BCL3 in a cervical cancer cell line

BCL3 is a putative proto-oncogene deregulated in haematopoieitic and solid tumours. It has been suggested that its oncogenic effects could be mediated, at least in part, by inducing proliferation and inhibiting cell death. To provide more insight into the mediators of these effects, we used an unbiased approach to analyse the mRNA expression changes after knocking-down BCL3 using specific shRNAs. One hundred eighty genes were up-regulated and sixtynine genes were down-regulated after knocking down BCL3. Function analyses showed enrichment in genes associated with cellular growth and proliferation, cell death and gene expression. We found that STAT3, an important oncogene in human cancer, was the central node of one of the most significant networks. We validated STAT3 as a bona fide target of BCL3 by additional interference RNA and in silico analyses of previously reported lymphoma patients.

Regulation of mitochondrial Smac/DIABLO-selective release by survivin

The intrinsic apoptotic pathway is characterized by the release of several mitochondrial intermembrane proteins into the cytosol of dying cells. It is unclear whether the release of these proteins follows a common or specific pathway. In the present report we show that survivin and, to a lesser extent, the survivin splice variant survivin DeltaEx3 regulate the specific liberation of second mitochondria-derived activator of caspase/direct IAP binding protein with low pI (Smac/DIABLO), an inhibitor of apoptosis proteins binding protein, during apoptosis induced by etoposide, a DNA damaging agent. This antineoplastic drug induced posttranscriptional upregulation of survivin and survivin DeltaEx3. In turn, mitochondrial survivin associated with Smac/DIABLO, delaying its release. In addition, cytosolic survivin also stabilized the cytosolic levels of released Smac/DIABLO. These results provide an explanation for the observed differences in the release of mitochondrial intermembrane proteins in various apoptotic models and present a new mechanism for the anti-apoptotic effects of survivin in cancer cells.

Tumor HGF lacks prognostic significance in Mexican breast cancer patients

Hepatocyte growth factor-scatter factor (HGF-SF) is a pleiotropic protein implicated in tumor formation and metastasis. Since increased levels of HGF-SF were first identified in breast cancer tissue or patient serum, some evidence has suggested that tumor or serum HGF-SF concentration could be one of the most accurate prognostic factors for this disease. However, other recent investigations have not been able to corroborate this finding. The study aims to establish the prognostic significance of HGF-SF in Mexican breast cancer women. Surgical specimens were obtained from 67 incident breast cancer patients at the Mexican National Cancer Institute between 1994 and 1995. Primary breast cancer tissue HGF-SF was measured by quantitative sandwich enzyme immunoassay. Relapse-free and overall survival curves were generated using Kaplan-Meier method. Significance of survival differences was calculated by log-rank test. chi2 was used for the association analysis between prognostic variables. Disease-free survival and overall survival were similar between the high tumor HGF group of patients and the low HGF patients (p = 0.7 and p = 0.36 respectively). No association was found between HGF and other clinicopathological variables (age, menopause status, clinical tumor size, clinical node involvement, metastasis, tumor grade, Estrogen Receptor and Progesterone Receptor). We found no prognostic significance for HGF, nor did we find a clear association between HGF and other known prognostic factors. A firm conclusion cannot be established regarding the role of HGF as a prognostic tool in breast cancer patients.

Benzene metabolites induce apoptosis in lymphocytes

Benzene is an important environmental pollutant with important health implications. Exposure to this aromatic hydrocarbon is associated with hematotoxicity, and bone marrow carcinogenic effects. It has been shown that benzene induces oxidative stress, cell cycle alterations, and programmed cell death in cultured cells. Hepatic metabolism of benzene is thought to be a prerequisite for its bone marrow toxicity. Nevertheless, there are no reports on the cellular effects of reactive intermediates derived from hepatic metabolism of benzene. Thus, the goal of this project was to determine the cellular alterations of benzene metabolites produced by the cultured hepatic cell line HepG2. Supernatants collected from these cells were applied to a culture of freshly isolated lymphocytes. A higher decrease in cell viability was found in cells exposed to these supernatants than to unmetabolized benzene. This viability decrease was due to apoptosis, as determined by Terminal deoxynucleotidyl Transferase Biotin-dUTP Nick End Labeling (TUNEL) assay and internucleosomal fragmentation of DNA. When supernatants were analyzed by HPLC, we found that not all the hydrocarbon was biotransformed, since a 28 microM concentration (37%) remained. The only metabolite found in the culture medium was muconic acid. The present results show that muconic acid derived from benzene metabolism is able to cooperate with the pollutant for the induction of apoptosis in rat lymphocytes.

Expression of integrin fraction and adhesion molecules on human granulosa cells and its relation with oocyte maturity and follicular steroidogenesis

PURPOSE

To study the correlation between the expression of integrin fractions and adhesion molecules on granulosa cells (GC) and follicular development.

METHODS

GC and follicular fluid (FF) were obtained at oocyte retrieval for ICSI. Expression of adhesion molecules on GC was studied by flow cytometry. Statistics were evaluated using the Student t test and simple linear regression analysis.

RESULTS

alpha5 integrin fraction was significantly (p < 0.01) higher, while alpha6 fraction and CD9 were significantly (p < 0.01 and p < 0.001, respectively) lower in GC from FF with metaphase II oocytes. A direct significant correlation was observed between FF progesterone and the alpha5 expression on GC (r = 0.54). In contrast, an inverse significant correlation was observed between FF progesterone level and the expression of alpha6 and CD9 (r = -0.40 and -0.41, respectively).

CONCLUSIONS

The expression pattern for integrin fractions and adhesion molecules may be of predictive value in assessing the state of differentiation of the human follicle.

Cupressus lusitanica (Cupressaceae) leaf extract induces apoptosis in cancer cells

A crude ethanolic extract of Cupressus lusitanica Mill. leaves demonstrate cytotoxicity in a panel of cancer cell lines. Cell death was due to apoptosis, as assessed by morphologic features (chromatin condensation and apoptotic bodies formation) and specific DNA fragmentation detected by in situ end-labeling of DNA breaks (TUNEL). The apoptotic cell death was induced timely in a dose-dependent manner. Despite the absence of changes in the expression levels of antiapoptotic protein Bcl-2, proapoptotic Bax protein variants omega and delta were increased. These results warrant further research of possible antitumor compounds in this plant.

Gemcitabine activity in cervical cancer cell lines

PURPOSE

Gemcitabine (2',2'-difluorodeoxycytidine) is an antineoplastic agent with activity against a variety of solid tumors. To investigate its in vitro activity toward cervical cancer, we exposed six cervical cancer cell lines to gemcitabine.

METHODS

Combinational cytotoxic studies using viability tests and clonogenicity assays.

RESULTS

Gemcitabine was cytostatic and cytotoxic in some of the lines at peak plasma concentrations similar to those achieved in clinical trials. Gemcitabine was also found to effectively synergize with cisplatin and showed a radiosensitizing effect in these cells. The cytotoxicity observed in sensitive cell lines was due to apoptosis, as demonstrated by DNA fragmentation assays.

CONCLUSIONS

We recommend performing additional in vitro experimentation so that these results can be confirmed to support clinical trials of gemcitabine in cervical cancer patients both as first-line therapy and with concomitant radiation.

Inhibitor of apoptosis-1 (IAP-1) expression and apoptosis in non-small-cell lung cancer cells exposed to gemcitabine11Abbreviations: IAP, inhibitor of apoptosis; TNF-α, tumor necrosis factor-α; NF-κB, nuclear factor-κB; RT-PCR, reverse transcriptase-polymerase chain reaction; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; and DTT, dithiothreitol

Exposure of lung cancer cells to gemcitabine (2',2'-difluorodeoxycytidine) arrests cells in S phase and induces secondary apoptotic cell death. Gemcitabine treatment decreased the expression of IkappaB-alpha protein and, concomitantly, increased the activity of nuclear factor-kappaB (NF-kappaB) transcription factor, a known inhibitor of the apoptotic response. This increase was accompanied by a similar increment in the expression of inhibitor of apoptosis-1 (IAP-1) protein and mRNA, a caspase inhibitor responsive to NF-kappaB. These changes were important to the final destiny of the cells, since overexpression of a dominant negative version of IkappaB-alpha, which suppresses NF-kappaB activation, blocks the increase of IAP-1 protein and potentiates the action of gemcitabine. Additionally, overexpression of IAP-1 protein in A549 cells expressing the IkappaB-alpha mutant restored the initial sensitivity to gemcitabine and demonstrated that this protein was responsible for the inhibitory effect of NF-kappaB. These results support the notion of IAP-1 as an important antiapoptotic protein mediating sensitivity to deoxynucleotides analogs in non-small-cell lung cancer cells.

A phase II study of gemcitabine and cisplatin combination as induction chemotherapy for untreated locally advanced cervical carcinoma

BACKGROUND

Cisplatin-based chemoradiation for locally advanced cervical carcinoma is now the standard of care for most patients with cervical carcinoma. However, induction chemotherapy followed by surgery, particularly with newer agents or combinations remains to be explored. This study was undertaken to evaluate the antitumor activity and toxicity of gemcitabine in combination with cisplatin for untreated locally advanced cervical carcinoma.

PATIENTS AND METHODS

Open-label, single center, phase II, non-randomized study of neoadjuvant gemcitabine plus cisplatin. Forty-one patients with histologic diagnosis of cervical carcinoma, with no previous treatment and staged as IB2 to IIIB, were treated with three 21-day courses of cisplatin 100 mg/m2 day I and gemcitabine 1000 mg/m2 days 1 and 8, followed by locoregional treatment with either surgery or concomitant chemoradiation. Response and toxicity were evaluated before each course and at the end of chemotherapy.

RESULTS

All patients were evaluated for toxicity and 40 for response. The overall objective response rate was 95% (95% confidence interval (CI): 88%-100%) being complete in 3 patients (7.5%) and partial in 35 (87.5%). A complete pathological response was found in 6 (26%) of the 23 patients that underwent surgery. Granulocytopenia grades 3-4 occurred in 13.8% and 3.4% of the courses, respectively, whereas non-hematological toxicity was mild.

CONCLUSIONS

Induction chemotherapy with the combination of gemcitabine and cisplatin is highly active for untreated cervical cancer patients and has an acceptable toxicity profile.

Weekly cisplatin/low-dose gemcitabine combination for advanced and recurrent cervical carcinoma

The aim of this study was to evaluate the activity and safety of the weekly cisplatin/low-dose gemcitabine combination in advanced or recurrent cervix cancer. Fourteen patients were treated with weekly chemotherapy consisting of gemcitabine 100 mg/m2 and cisplatin 33 mg/m2 for a maximum of 18 courses (6 months). The response rate and survival was evaluated. The mean age of patients was 43.4 years, 13 out of 14 had pelvic disease, and most of them received previous irradiation. Eleven patients were evaluated for response and all for toxicity. The mean number of courses delivered was 9.7. Four patients (36%) achieved a partial response and four had stable disease. The most frequent toxicity was nausea/vomiting;myelosuppression was mild and uncommon. At a maximum follow-up of 15 months the median survival was 6 months. This is an active and well-tolerated combination devoid of myelotoxic effects which allows its administration without delays.

Surfactant components modulate fibroblast apoptosis and type I collagen and collagenase-1 expression

During lung injury, fibroblasts migrate into the alveolar spaces where they can be exposed to pulmonary surfactant. We examined the effects of Survanta and surfactant protein A (SP-A) on fibroblast growth and apoptosis and on type I collagen, collagenase-1, and tissue inhibitor of metalloproteinase (TIMP)-1 expression. Lung fibroblasts were treated with 100, 500, and 1,000 microg/ml of Survanta; 10, 50, and 100 microg/ml of SP-A; and 500 microg/ml of Survanta plus 50 microg/ml of SP-A. Growth rate was evaluated by a formazan-based chromogenic assay, apoptosis was evaluated by DNA end labeling and ELISA, and collagen, collagenase-1, and TIMP-1 were evaluated by Northern blotting. Survanta provoked fibroblast apoptosis, induced collagenase-1 expression, and decreased type I collagen affecting mRNA stability approximately 10-fold as assessed with the use of actinomycin D. Collagen synthesis and collagenase activity paralleled the gene expression results. SP-A increased collagen expression approximately 2-fold and had no effect on collagenase-1, TIMP-1, or growth rate. When fibroblasts were exposed to a combination of Survanta plus SP-A, the effects of Survanta were partially reversed. These findings suggest that surfactant lipids may protect against intraluminal fibrogenesis by inducing fibroblast apoptosis and decreasing collagen accumulation.

Cloning and expression of guinea pig TIMP-2. Expression in normal and hyperoxic lung injury

Tissue inhibitors of metalloproteinases (TIMPs) play a key regulatory role in extracellular matrix remodeling. By screening a lung library with a human TIMP-2 cDNA probe, we have isolated the cDNA corresponding to guinea pig TIMP-2. The 3.5-kb cDNA presents an open reading frame that predicts a protein of 220 amino acids showing 97.2, 96.8, 97.2, and 77.3% overall identity with human, mouse, rat, and chicken TIMP-2, respectively. Guinea pig TIMP-2 cDNA was expressed in CHO-K1 cells, showing a protein with the expected molecular weight and activity. Northern blot analysis revealed TIMP-2 expression in brain, kidney, intestine, spleen, heart, and lung. Transforming growth factor-beta downregulated TIMP-2 mRNA in guinea pig lung fibroblasts, whereas a variety of other stimuli showed no effect. In normal and hyperoxia-exposed lungs, TIMP-2 mRNA was mainly localized in alveolar macrophages and epithelial cells. No quantitative differences were found by Northern blot. These results confirm that TIMP-2 is highly conserved in mammals and largely expressed in lungs.

Mitochondrial changes during the apoptotic process of HeLa cells exposed to cisplatin

HeLa cells undergo apoptosis after exposure to cisplatin. Since mitochondria have recently been proposed as a probable effector of this type of cell death, we performed an analysis using the fluorescent cation rhodamine 123, which is transported actively by this organelle. Cisplatin induces a decrease in the mitochondrial staining, as assessed by cytofluorometric analysis. Microscopic analysis demonstrated that this effect was accompanied by damage of the mitochondria. These features were not exclusive of cisplatin, as other antineoplasic agents (taxol, etoposide) elicited similar effects. These results point toward the notion of a general effect of antineoplasic drugs over the mitochondria during induction of apoptotic cell death.

Gelatinases A and B are up-regulated in rat lungs by subacute hyperoxia: pathogenetic implications

Subacute hyperoxia may cause basement membrane disruption and subsequent fibrosis. To test the role of extracellular matrix degradation in hyperoxic damage, we analyzed the expression of gelatinases A and B and tissue inhibitors of metalloproteinases (TIMP)-1 and TIMP-2 in rats exposed to 85% O2. Oxygen-exposed rats were studied at 1, 3, 5, and 7 days, and compared with air-breathing rats. Lung mRNAs assayed by Northern and in situ hybridization showed an up-regulation of lung gelatinases A and B from the 3rd day on. Gelatinase A was localized in alveolar macrophages and in interstitial and alveolar epithelial cells. Gelatinase B mRNA and protein were localized in macrophages and bronchiolar and alveolar epithelial cells. Increased gelatinase A and B activities were demonstrated in bronchoalveolar lavage. TIMP-1 and TIMP-2 were constitutively expressed, and only TIMP-1 displayed a moderate increase with hyperoxia. To elucidate transcriptional mechanisms for increased gelatinase B expression after hyperoxia, nuclear transcription factor-kappabeta activation was explored. Oxidative stress significantly increased the lung expression of nuclear transcription factor-kappabeta (p65) protein, and nuclear transcription factor-kappabeta activation and increased levels of gelatinases A and B were found in isolated type II alveolar cells obtained from hyperoxic rats. Conceivably, subacute hyperoxia induces excessive gelatinase activity, which may contribute to lung damage.

Cisplatin-induced apoptosis of HeLa cells. Effect of RNA and protein synthesis inhibitors, Ca2+ chelators and zinc

HeLa cells exposed to cisplatin undergo cell death, presenting morphological and biochemical characteristics typical of apoptosis. In this study we demonstrate that this process is independent of RNA and protein synthesis, since it was not inhibited by actinomycin D or cycloheximide. These substances induced apoptosis by themselves, suggesting an unidentified short-lived inhibitor. The presence of Ca2+ chelators (EDTA and EGTA) did not have effect in this process, excluding the participation of extracellular Ca2+ access. Finally, zinc ions inhibited the low molecular weight DNA degradation and the apoptotic bodies production, but not cell death. These results provide an insight into the mechanism of action of one of the most used antineoplastic drug.

Modulation of NF-kappa B, and Bcl-2 in apoptosis induced by cisplatin in HeLa cells

Cisplatin exposure induces apoptosis in HeLa cells. Since the interaction of this drug with DNA produces reactive oxygen species, we performed an analysis of the oxidative stress-responsive factors AP-1 and NF-kappa B. Although AP-1 levels were not modified during cisplatin exposure, electrophoretic mobility shift assays demonstrated an increase in NF-kappa B DNA binding activity that correlated with a decrease of the inhibitory protein I kappa B alpha and a specific relocalization of c-Rel, as assessed by immunoblotting and immunofluorescence. No changes in the levels or localization of p65 were found. Interestingly, I kappa B alpha relocalized to the nucleus, probably in order to regulate the binding of specific complexes. This process was accompanied by a decrease of the antiapoptotic protein Bcl-2, and a relocalization of p53 protein to the nucleus. Since HeLa cells lost most of their p53 protein due to a specific E6-dependent degradation, cisplatin could be inhibiting this degradation, since the p53 total levels were not increased during the exposure to the drug.

Anopheles aquasalis eggs from two Venezuelan localities compared by scanning electron microscopy

Anopheles (Nyssorhynchus) aquasalis, is the main coastal vector of malaria from northeastern Venezuela to southeastern Brazil. Several authors have argued that An. aquasalis is a highly polymorphic species while others indicated that it is a complex of closely related species. This investigation compared the morphology of An. aquasalis eggs from Sinamaica (Zulia State) and Yaguaraparo (Sucre State), the west and east of Venezuela, respectively. We were able to separate eggs from the two localities using discriminant analyses based on ratios and percentages of anterior and posterior tubercles measured by scanning electron microscopy. The results of this work suggest that An. aquasalis has high intraspecific variation.

Subcellular redistribution of HSP72 protein during cisplatin-induced apoptosis in HeLa cells

Exposure of HeLa cells to cisplatin results in the activation of apoptotic cell death. This drug induces DNA damage and generates reactive oxygen intermediates. Since cisplatin is highly reactive and binds to diverse proteins, it could create abnormal protein structures or nonspecific aggregates. For these reasons, we analyzed the expression and subcelullar distribution of hsp72, a heat-shock protein that enables cells under stress to cope with damaged proteins. We did not observe any changes in the expression of hsp72 protein, although, by immunofluorescence studies, we detected a dramatic redistribution of the protein. These results and its probable relevance in the drug-induced apoptotic phenomenon are discussed.

Effect of melatonin on beta-tubulin and MAP2 expression in NIE-115 cells

Physiological concentrations of the pineal hormone melatonin induce an increase of microtubules in neuroblastoma NIE-115 cells. This effect is due to an increase in the polymerization state of tubulin. Concomitantly, higher levels of soluble beta-tubulin are present in the treated cells. Unexpectedly, no significant changes in the levels of beta-tubulin or its mRNA occur in the presence of melatonin reflecting perhaps a strict control of its steady state in a physiological context. In contrast, higher amounts of microtubule-associated-protein 2 are found when the cells are exposed to melatonin. These findings support the idea that tubulin polymerization process is one of the targets of melatonin action. Furthermore, our results might explain the increase in the length and number of neurites present in these cells when they are treated with this hormone.

Paclitaxel-induced apoptosis in HeLa cells is serum dependent

Exposure of HeLa cells to different concentrations of the antineoplastic drug paclitaxel resulted in a loss of cell viability that was dependent on the concentration and time of exposure to the drug. This phenomenon was associated with the appearance of nuclear morphology typical of apoptosis and DNA breakage into a "ladder" pattern of discrete fragments of nucleosomal size. The induction of cell death was dependent on the serum concentration of the culture media, repressed by pretreatment with a cAMP-dependent protein kinase (PKA) inhibitor, and enhanced by increasing the cell proliferation with previous exposure to a cAMP-analog and a protein kinase-C (PKC) inducer. The proliferative index modifies the effect of taxol on HeLa cells, probably by means of a more rapid accumulation of cells in the G2/M cycle blockage point, although a direct participation of PKA and PKC should not be excluded.

Internucleosomal DNA cleavage in HeLa cells exposed to cisplatin

Exposure of HeLa cells to Cisplatin resulted in cell death characteristic of a suicide process known as apoptosis, as stated by morphologic features, extensive and specific DNA fragmentation and in situ end labeling of DNA breaks. The apoptotic cell death was induced timely in a dose-dependent manner, without any primary necrosis at the concentrations used. In contrast to other reports, the death in this cell line was accompanied by low-molecular weight DNA fragmentation. These results and their relevance to the apoptotic process are discussed.

Regulation of apo B mRNA expression in liver and intestine during liver regeneration induced by CCl4

Acute liver damage in CCl4-treated rats is accompanied by a decrease of the lipoprotein particles HDL and VLDL. However, once the regenerative process has occurred both lipoproteins increase to values higher than control. In this study we have further analyzed the molecular mechanism involved in the induction of the hyperlipidemia during liver regeneration in rats treated with CCl4. The expression of apolipoprotein (apo) B gene at the apo B mRNA editing level has been analyzed during the regenerative process of the liver. The percent of apo B-48 and apo B-100 mRNA was determined and compared to the plasma levels of LDL and VLDL. These results confirm the existence of two different hyperlipidemic stages during liver regeneration. Total apo B mRNA is increased in liver and intestine during both hyperlipidemic stages. The ratio of apo B-100/apo B-48 mRNA remains constant during the first hyperlipidemic stage but the serum levels of VLDL are decreased. Then once the regenerative process has occurred, the steady-state levels of total apo B mRNA remaining, increased with higher amounts of apo B-100 than apo B-48. At this experimental time point the high levels of total apo B mRNA correlate with serum levels of VLDL that are significantly higher than control. These results indicate that apo B gene expression is induced at the mRNA level in liver and intestine during liver regeneration affecting the apo B mRNA editing mechanism in a complex manner and suggest further regulation at the translational or post-translational level.

[New strategies in the clinical evaluation of patients with colon cancer based on molecular studies]

During the last five years molecular studies allowed important advances in the knowledge of cancer colon with important clinical implications. The main finding was the identification and sequence analysis of the APC gen. Structural alterations of this gene have been detected in patients with Familial Adenomatous Polyposis and Gardner syndrome, which suggest a common disease. Furthermore, alterations of the APC gen appears to be also altered in cases of cancer of colon sporadic. Indicating that structural alteration of the APC gen can be inherited and/or acquired. Restriction fragment-length polymorphisms in the chromosome 5q21-22 can now be used clinically for premorbid diagnosis and counseling in familial adenomatous polyposis. The molecular studies allow the clinician to have a new approach in the management and screening of families with familial adenomatous polyposis. The sequence analysis and specific identification of the structural alteration of the APC gene is a more expensive and sophisticated study, although represent a more direct approach. In the Department of Gastroenterology of the INNSZ we are performing such molecular studies. The main purpose of our group is to proportionate integral clinical-molecular studies for families with hereditary colon cancer, create a national register of these diseases and investigate the molecular bases in order to generate new molecular diagnosis tools.

Cerebral gigantism associated with Wilms' tumor

Two children had cerebral gigantism in unique association with Wilms' tumor. An increased incidence of neoplasms has been reported in cerebral gigantism, as well as in Beckwith-Wiedemann syndrome. We report similarities and differences between these disorders.