Iván Gallegos

The expression of syndecan-1 and -2 is associated with Gleason score and epithelial-mesenchymal transition markers, E-cadherin and β-catenin, in prostate cancer

The epithelial-mesenchymal transition (EMT) is considered a key step in tumor progression, where the invasive cancer cells change from epithelial to mesenchymal phenotype. During this process, a decrease or loss in adhesion molecules expression and an increase in migration molecules expression are observed. The aim of this work was to determine the expression and cellular distribution of syndecan-1 and -2 (migration molecules) and E-cadherin and beta-catenin (adhesion molecules) in different stages of prostate cancer progression. A quantitative immunohistochemical study of these molecules was carried out in tissue samples from benign prostatic hyperplasia and prostate carcinoma, with low and high Gleason score, obtained from biopsies archives of the Clinic Hospital of the University of Chile and Dipreca Hospital. Polyclonal specific antibodies and amplification system of estreptavidin-biotin peroxidase and diaminobenzidine were used. Syndecan-1 was uniformly expressed in basolateral membranes of normal epithelium, changing to a granular cytoplasmatic expression pattern in carcinomas. Syndecan-2 was observed mainly in a cytoplasmatic granular pattern, with high immunostaining intensity in areas of low Gleason score. E-cadherin was detected in basolateral membrane of normal epithelia showing decreased expression in high Gleason score samples. beta-Catenin was found in cell membranes of normal epithelia changing its distribution toward the nucleus and cytoplasm in carcinoma samples. We concluded that changes in expression and cell distribution of E-cadherin and beta-catenin correlated with the progression degree of prostate adenocarcinoma, suggesting a role of these molecules as markers of progression and prognosis. Furthermore, changes in the pattern expression of syndecan-1 and -2 indicate that both molecules may be involved in the EMT and tumor progression of prostate cancer.

Proapoptotic effect of endocannabinoids in prostate cancer cells

In the early stages, prostate cancer is androgen- dependent; therefore, medical castration has shown significant results during the initial stages of this pathology. Despite this early effect, advanced prostate cancer is resilient to such treatment. Recent evidence shows that derivatives of Cannabis sativa and its analogs may exert a protective effect against different types of oncologic pathologies. The purpose of the present study was to detect the presence of cannabinoid receptors (CB1 and CB2) on cancer cells with a prostatic origin and to evaluate the effect of the in vitro use of synthetic analogs. In order to do this, we used a commercial cell line and primary cultures derived from prostate cancer and benign prostatic hyperplasia. The presence of the CB1 and CB2 receptors was determined by immunohistochemistry where we showed a higher expression of these receptors in later stages of the disease (samples with a high Gleason score). Later, treatments were conducted using anandamide, 2-arachidonoyl glycerol and a synthetic analog of anandamide, methanandamide. Using the MTT assay, we proved that the treatments produced a cell growth inhibitory effect on all the different prostate cancer cultures. This effect was demonstrated to be dose-dependent. The use of a specific CB1 receptor blocker (SR141716) confirmed that this effect was produced primarily from the activation of the CB1 receptor. In order to understand the MTT assay results, we determined cell cycle distribution by flow cytometry, which showed no variation at the different cell cycle stages in all the cultures after treatment. Treatment with endocannabinoids resulted in an increase in the percentage of apoptotic cells as determined by Annexin V assays and caused an increase in the levels of activated caspase-3 and a reduction in the levels of Bcl-2 confirming that the reduction in cell viability noted in the MTT assay was caused by the activation of the apoptotic pathway. Finally, we observed that endocannabinoid treatment activated the Erk pathway and at the same time, produced a decrease in the activation levels of the Akt pathway. Based on these results, we suggest that endocannabinoids may be a beneficial option for the treatment of prostate cancer that has become nonresponsive to common therapies.

Molecular signature of cancer stem cells isolated from prostate carcinoma and expression of stem markers in different Gleason grades and metastasis

Prostate cancer (PCa) is the most frequently diagnosed malignancy in men worldwide. Chemotherapy response is very poor and resistance to hormone-based treatments is frequent in advances stages. Recently, tumor-initiating cells or cancer stem cells (CSCs) have been identified in several cancers, including PCa. These cells are thought to be responsible for therapy resistance, relapse and metastasis. In the present work, enriched populations of CSCs were obtained using a mixed procedure that included differential clone-forming ability, sphere growing induction (prostatospheres) and magnetic-associated cell sorting (MACS). Also, stem marker expression was determined in PCa biopsies of different histological grades and metastasis samples. The signature for stem markers of the isolated CSCs was CD133+/CD44+/ABCG2+/ CD24-. Expression of stem markers (CD133, CD44, and ABCG2) was higher in medium Gleason biopsies than in lower and higher grades, and lymph-node and bone metastasis samples. These results suggest that the CSCs in PCa reach an important number in medium Gleason grades, when the tumor is still confined into the gland. At this stage, the surgical treatment is usually with curative intention. However, an important percentage of patients relapse after treatment. Number and signature of CSCs may be a prognosis factor for PCa recurrence.

Increased SNAIL expression and low syndecan levels are associated with high Gleason grade in prostate cancer

Prostate cancer (PC) is a leading male oncologic malignancy wideworld. During malignant transformation, normal epithelial cells undergo genetic and morphological changes known as epithelial-mesenchymal transition (EMT). Several regulatory genes and specific marker proteins are involved in PC EMT. Recently, syndecans have been associated with malignancy grade and Gleason score in PC. Considering that SNAIL is mainly a gene repressor increased in PC and that syndecan promoters have putative binding sites for this repressor, we propose that SNAIL might regulate syndecan expression during PC EMT. The aim of this study was to analyze immunochemically the expression of SNAIL, syndecans 1 and 2 and other EMT markers in a tissue microarray (TMA) of PC samples and PC cell lines. The TMAs included PC samples of different Gleason grade and benign prostatic hyperplasia (BPH) samples, as non-malignant controls. PC3 and LNCaP cell lines were used as models of PC representing different tumorigenic capacities. Semi-quantitative immunohistochemistry was performed on TMAs and fluorescence immunocytochemistry and western blot analysis were conducted on cell cultures. Results show that SNAIL exhibits increased expression in high Gleason specimens compared to low histological grade and BPH samples. Accordingly, PC3 cells show higher SNAIL expression levels compared to LNCaP cells. Conversely, syndecan 1, similarly to E-cadherin (a known marker of EMT), shows a decreased expression in high Gleason grades samples and PC3 cells. Interestingly, syndecan 2 shows no changes associated to histological grade. It is concluded that increased SNAIL levels in advanced PC are associated with low expression of syndecan 1. The mechanism by which SNAIL regulates the expression of syndecan 1 remains to be investigated.

Altered expression patterns of syndecan-1 and -2 predict biochemical recurrence in prostate cancer

The clinical features of prostate cancer do not provide an accurate determination of patients undergoing biochemical relapse and are therefore not suitable as indicators of prognosis for recurrence. New molecular markers are needed for proper pre-treatment risk stratification of patients. Our aim was to assess the value of altered expression of syndecan-1 and -2 as a marker for predicting biochemical relapse in patients with clinically localized prostate cancer treated by radical prostatectomy. The expression of syndecan-1 and -2 was examined by immunohistochemical staining in a series of 60 paraffin-embedded tissue samples from patients with localized prostate cancer. Ten specimens from patients with benign prostatic hyperplasia were used as non-malignant controls. Semiquantitative analysis was performed to evaluate the staining patterns. To investigate the prognostic value, Kaplan-Meier survival curves were performed and compared by a log-rank test. In benign samples, syndecan-1 was expressed in basal and secretory epithelial cells with basolateral membrane localisation, whereas syndecan-2 was expressed preferentially in basal cells. In prostate cancer samples, the expression patterns of both syndecans shifted to granular-cytoplasmic localisation. Survival analysis showed a significant difference (P < 0.05) between normal and altered expression of syndecan-1 and -2 in free prostate-specific antigen recurrence survival curves. These data suggest that the expression of syndecan-1 and -2 can be used as a prognostic marker for patients with clinically localized prostate cancer, improving the prostate-specific antigen recurrence risk stratification.

Immunohistochemistry expression of P53, Ki67, CD30, and CD117 and presence of clinical metastasis at diagnosis of testicular seminoma.

IntroductionWe evaluated the immunohistochemical expression of p53, Ki67, CD30, and CD117 and correlated it with histological features and presence of clinical metastasis at diagnosis of testicular seminomas. Materials and MethodsA retrospective study of 62 patients was performed in patients with pure seminoma. The retroperitoneum was staged with computed tomography scan and the thorax with simple x-rays and/or computed tomography scan. Pathologists were unaware of the clinical stage of the patients. Manual microarrays were created from a tissue representative of tumor. The expression of p53, Ki67, CD30, and CD117 was evaluated as negative, any degree of expression, and expression in more than 50% of neoplastic cells. Univariate and multivariate analysis were performed. ResultsSixty-two cases were analyzed: 43 cases were in clinical stage I (69.4%), 17 were in clinical stage II (27.4%), and 2 were in clinical stage III (3.2%). Fifty-six cases expressed CD117 (90%), 42 p53 (68%), 8 CD30 (13%), and all cases Ki67. There were no differences in p53, Ki67, CD30, and CD117 expression between testicular seminoma with and without clinical metastasis at diagnosis, regardless of the magnitude of expression. Neither of them found positive association between these marker expressions and morphologic risk factors such as tumor size greater than 6 cm and rete testis invasion. ConclusionsThis study shows that expression of p53, Ki67, and CD30 and loss of CD117 expression fail to predict the presence of clinical metastasis at diagnosis of testicular seminoma and do not correlate with other histopathological risk factors in clinical stage I patients.

Detección de lesiones preneoplásicas gástricas mediante niveles séricos de pepsinógeno en población chilena

Gastric cancer has a direct relation with chronicatrophic gastritis (AG) and intestinal metaplasia (IM), considered as preneoplastic lesions.Determination of serum pepsinogen I levels (PGI) and pepsinogen I / pepsinogen II ratio (PGI/PGII)can detect this conditions; achieving 70-90% of gastric cancer detection in early stages.

Downregulation of the Sonic Hedgehog/Gli pathway transcriptional target Neogenin-1 is associated with basal cell carcinoma aggressiveness

Basal Cell Carcinoma (BCC) is one of the most diagnosed cancers worldwide. It develops due to an unrestrained Sonic Hedgehog (SHH) signaling activity in basal cells of the skin. Certain subtypes of BCC are more aggressive than others, although the molecular basis of this phenomenon remains unknown. We have previously reported that Neogenin-1 (NEO1) is a downstream target gene of the SHH/GLI pathway in neural tissue. Given that SHH participates in epidermal homeostasis, here we analyzed the epidermal expression of NEO1 in order to identify whether it plays a role in adult epidermis or BCC. We describe the mRNA and protein expression profile of NEO1 and its ligands (Netrin-1 and RGMA) in human and mouse control epidermis and in a broad range of human BCCs. We identify in human BCC a significant positive correlation in the levels of NEO1 receptor, NTN-1 and RGMA ligands with respect to GLI1, the main target gene of the canonical SHH pathway. Moreover, we show via cyclopamine inhibition of the SHH/GLI pathway of ex vivo cultures that NEO1 likely functions as a downstream target of SHH/GLI signaling in the skin. We also show how Neo1 expression decreases throughout BCC progression in the K14-Cre:Ptch1lox/lox mouse model and that aggressive subtypes of human BCC exhibit lower levels of NEO1 than non-aggressive BCC samples. Taken together, these data suggest that NEO1 is a SHH/GLI target in epidermis. We propose that NEO1 may be important in tumor onset and is then down-regulated in advanced BCC or aggressive subtypes.

Actinomicosis torácica como diagnóstico diferencial de neoplasia: a propósito de un caso

Actinomycosis is an infrequent infection caused by bacteria from Actinomyces genus that manifests as a chronic, suppurative and progressive disease. Its more common in men. Thoracic actinomycosis occurs in 15% of the cases, and infection of the chest wall is less frequent. The clinical presentation mimics tuberculosis or neoplastic processes. In this article we present the case of a 63 year-old man with no comorbidity, with pulmonary actinomy- cosis involving the chest wall mimicking a neoplastic process, basing the diagnosis on histopathologic fi ndings.

The Netrin-4/Laminin γ1/Neogenin-1 complex mediates migration in SK-N-SH neuroblastoma cells

ABSTRACT Neuroblastoma (NB) is the most common pediatric extracranial solid tumor. It arises during development of the sympathetic nervous system. Netrin-4 (NTN4), a laminin-related protein, has been proposed as a key factor to target NB metastasis, although there is controversy about its function. Here, we show that NTN4 is broadly expressed in tumor, stroma and blood vessels of NB patient samples. Furthermore, NTN4 was shown to act as a cell adhesion molecule required for the migration induced by Neogenin-1 (NEO1) in SK-N-SH neuroblastoma cells. Therefore, we propose that NTN4, by forming a ternary complex with Laminin γ1 (LMγ1) and NEO1, acts as an essential extracellular matrix component, which induces the migration of SK-N-SH cells.