In Vitro and In Vivo Cysticidal Effects of Carica Papaya Cell Suspensions.

Parasitic diseases are a major public health problem worldwide. Plant-derived products appear to be ideal candidates from a biotechnological perspective, being sustainable and environmentally friendly. The antiparasitic properties of Carica papaya have been attributed to some of its components, including papain and other compounds that are concentrated in the latex and seeds. This study demonstrated in vitro a high and insignificantly different cysticidal activity of soluble extract that was obtained after the disruption of nontransformed wild-type (WT) cells as well as transformed papaya calluses (PC-9, PC-12, and PC-23) and papaya cell suspensions (CS-9, CS-12, and CS-23). In vivo, cell suspensions of CS-WT and CS-23 that had been previously lyophilized were tested with respect to their cysticidal effects, compared with those of three commercial antiparasitic drugs. CS-WT and CS-23 together reduced the number of cysticerci, the number of buds, and the percentage of calcified cysticerci in a similar extent to albendazole and niclosamide, whereas ivermectin was less effective. Mice were then orally immunized with CS-23 that expressed the anti-cysticercal KETc7 antigen (10 µg/mouse), CS-WT (10 mg/mouse), or both together to evaluate their preventive properties. CS-23 and CS-WT significantly reduced the expected parasite and increased the percentage of calcified cysticerci as well as recovery, being more effective when employed together. The results reported in this study support the feasibility of the development of an anti-cysticercosis vaccine from cells of C. papaya in in vitro cultures, as they are a source of an anthelmintic, natural, and reproducible product.

Why are tapeworm carriers so difficult to find? A methodological proposal for their search and recovery.

Neurocysticercosis, caused by the larval stage of Taenia solium, is a life-threatening condition and the most severe form of the disease. Yet, despite being a required link in the parasite life cycle, tapeworm carriers are rarely reported. This study is aimed to find and evaluate T. solium carriers, describing some characteristics of these patients and the treatment. Taeniasis cases were searched for in various Mexican states from 1983 to 2016. Previous informed consent, tapeworm-carrier patients were administered with niclosamide and a saline purge. Parasite specimens were recovered and identified, both morphologically and by PCR. From 117 treated patients, Taenia sp. specimens were obtained from 46 subjects (47.8%). From these, complete parasites were recovered from 42 (90.5%), and only detached proglottids from 4 patients. Cases were more frequent in Morelos, Chiapas, and Guerrero. More than one adult cestode was recovered from 4 patients (9.5%). To improve treatment efficacy and adherence, the drug was administered in late afternoon, resulting a high recovery yield of complete parasites (90.5%). The success rate of deworming campaigns in areas of Mexico and the world that are endemic for Taenia sp. could be improved by administering the treatment at times that do not interfere with the patients' daily activities, and national health authorities could apply this simple strategy to help eradication efforts in endemic areas. The detection of carriers will only be possible through the coordinated efforts of public and private health services, a better education of the general population to improve self-detection, and adequate, personalized diagnostic procedures for suspect cases.

Contribution of Stemness-Linked Transcription Regulators to the Progression of Breast Cancer.

Although there are currently several factors that allow measuring the risk of having breast cancer or predicting its progression, the underlying causes of this malignancy have remained unknown. Several molecular studies have described some mechanisms involved in the progress of breast cancer. These have helped in identifying new targets with therapeutic potential. However, despite the therapeutic strategies implemented from the advances achieved in breast cancer research, a large percentage of patients with breast cancer die due to the spread of malignant cells to other tissues or organs, such as bones and lungs. Therefore, determining the processes that promote the migration of malignant cells remains one of the greatest challenges for oncological research. Several research groups have reported evidence on how the dedifferentiation of tumor cells leads to the acquisition of stemness characteristics, such as invasion, metastasis, the capability to evade the immunological response, and resistance to several cytotoxic drugs. These phenotypic changes have been associated with a complex reprogramming of gene expression in tumor cells during the Epithelial- Mesenchymal Transition (EMT). Considering the determining role that the transcriptional regulation plays in the expression of the specific characteristics and attributes of breast cancer during ETM, in the present work, we reviewed and analyzed several transcriptional mechanisms that support the mesenchymal phenotype. In the same way, we established the importance of transcription factors with a therapeutic perspective in the progress of breast cancer.

Treatment of Breast Cancer With Gonadotropin-Releasing Hormone Analogs.

Although significant progress has been made in the implementation of new breast cancer treatments over the last three decades, this neoplasm annually continues to show high worldwide rates of morbidity and mortality. In consequence, the search for novel therapies with greater effectiveness and specificity has not come to a stop. Among the alternative therapeutic targets, the human gonadotropin-releasing hormone type I and type II (hGnRH-I and hGnRH-II, respectively) and its receptor, the human gonadotropin-releasing hormone receptor type I (hGnRHR-I), have shown to be powerful therapeutic targets to decrease the adverse effects of this disease. In the present review, we describe how the administration of GnRH analogs is able to reduce circulating concentrations of estrogen in premenopausal women through their action on the hypothalamus-pituitary-ovarian axis, consequently reducing the growth of breast tumors and disease recurrence. Also, it has been mentioned that, regardless of the suppression of synthesis and secretion of ovarian steroids, GnRH agonists exert direct anticancer action, such as the reduction of tumor growth and cell invasion. In addition, we discuss the effects on breast cancer of the hGnRH-I and hGnRH-II agonist and antagonist, non-peptide GnRH antagonists, and cytotoxic analogs of GnRH and their implication as novel adjuvant therapies as antitumor agents for reducing the adverse effects of breast cancer. In conclusion, we suggest that the hGnRH/hGnRHR system is a promising target for pharmaceutical development in the treatment of breast cancer, especially for the treatment of advanced states of this disease.

Anti-GK1 antibodies damage Taenia crassiceps cysticerci through complement activation.

Taeniasis-cysticercosis, a zoonosis caused by Taenia solium, is prevalent in underdeveloped countries, where marginalization promotes its continued transmission. Pig cysticercosis, an essential stage for transmission, is preventable by vaccination. An efficient multiepitope vaccine against pig cysticercosis, S3Pvac, was developed. Previous studies showed that antibodies against one of the S3Pvac components, GK-1, are capable of damaging T. solium cysticerci, inhibiting their ability to transform into the adult stage in golden hamster gut. This study is aimed to evaluate one of the mechanisms that could mediate anti-GK-1 antibody-dependent protection. To this end, pig anti-GK-1 antibodies were produced and purified by using protein A. Proteomic analysis showed that the induced antibodies recognized the respective native cysticercal protein KE7 (Bobes et al. Infect Immun 85:e00395-17, 2017) and two additional T. solium proteins (endophilin B1 and Gp50). A new procedure to evaluate cysticercus viability, based on quantifying the cytochrome c released after parasite damage, was developed. Taenia crassiceps cysticerci were cultured in the presence of differing amounts of anti-GK-1 antibody and complement in a saturating concentration, along with the respective controls. Cysticercus viability was assessed by recording parasite motility, trypan blue exclusion, and cytochrome c levels in cysticercal soluble extract. Anti-GK-1 antibody significantly increased cysticercus damage as measured by all three methods. Parasite evaluation by electron microscopy after treatment with anti-GK-1 antibody plus complement demonstrated cysticercus damage as shorter, capsule-severed microtrichia; a decrease in glycocalyx length with respect to untreated cysts; and disaggregated desmosomes. These results demonstrate that anti-GK-1 antibodies damage cysticerci through classic complement activation.

Activation of human gonadotropin-releasing hormone receptor promotes down regulation of ARHGAP18 and regulates the cell invasion of MDA-MB-231 cells.

The Gonadotropin-Releasing Hormone Receptor (GnRHR) is expressed mainly in the gonadotrope membrane of the adenohypophysis and its natural ligand, the Gonadotropin-Releasing Hormone (GnRH), is produced in anterior hypothalamus. Furthermore, both molecules are also present in the membrane of cells derived from other reproductive tissues such as the breast, endometrium, ovary, and prostate, as well as in tumors derived from these tissues. The functions of GnRH receptor and its hormone in malignant cells have been related with the decrease of proliferation and the invasiveness of those tumors however, little is known about the molecules associated with the signaling pathways regulated by both molecules in malignant cells. To further analyze the potential mechanisms employed by the GnRHR/GnRH system to reduce the tumorigenesis of the highly invasive breast cancer cell line MDA-MB-231, we performed microarrays experiments to evaluated changes in genes expression and validate these modifications by functional assays. We show that activation of human GnRHR is able to diminish the expression and therefore functions of the Rho GTPase-Activating Protein 18 (ARHGAP18). Decrease of this GAP following GnRHR activation, correlates to the higher of cell adhesion and also with reduction of tumor cell invasion, supporting the notion that GnRHR triggers intracellular signaling pathways that acts through ARHGAP18. On the contrary, although a decline of cellular proliferation was observed during GnRHR activation in MDA-MB-231, this was independent of ARHGAP18 showing the complex system in which is involved the signaling pathways regulated by the GnRHR/GnRH system.

Effects of the lifestyle habits in breast cancer transcriptional regulation.

Through research carried out in the last 25 years about the breast cancer etiology, it has been possible to estimate that less than 10 % of patients who are diagnosed with the condition are carriers of some germline or somatic mutation. The clinical reports of breast cancer patients with healthy twins and the development of disease in women without high penetrance mutations detected, warn the participation more factors in the transformation process. The high incidence of mammary adenocarcinoma in the modern woman and the urgent need for new methods of prevention and early detection have demanded more information about the role that environment and lifestyle have on the transformation of mammary gland epithelial cells. Obesity, alcoholism and smoking are factors that have shown a close correlation with the risk of developing breast cancer. And although these conditions affect different cell regulation levels, the study of its effects in the mechanisms of transcriptional and epigenetic regulation is considered critical for a better understanding of the loss of identity of epithelial cells during carcinogenesis of this tissue. The main objective of this review was to establish the importance of changes occurring to transcriptional level in the mammary gland as a consequence of acute or chronic exposure to harmful products such as obesity-causing foods, ethanol and cigarette smoke components. At analyze the main studies related to topic, it has concluded that the understanding of effects caused by the lifestyle factors in performance of the transcriptional mechanisms that determine gene expression of the mammary gland epithelial cells, may help explain the development of this disease in women without genetic propensity and different phenotypic manifestations of this cancer type.

A través de la investigación realizada en los últimos 25 años en torno a la etiología del cáncer de mama, ha sido posible estimar que menos del 10 % de las pacientes que son diagnosticadas con la enfermedad son portadoras de alguna mutación de línea germinal o somática. Los informes clínicos de pacientes de cáncer de mama con gemelas saludables y el desarrollo de la enfermedad en las mujeres sin mutaciones de alta penetrancia detectadas, advierten la participación de otros factores en el proceso de transformación. La alta incidencia de adenocarcinoma de mama en la mujer moderna y la necesidad urgente de nuevos métodos para la prevención y detección temprana han exigido una mayor información en relación al papel que el medio ambiente y el estilo de vida tienen en la transformación de las células epiteliales de la glándula mamaria. La obesidad, el alcoholismo y el tabaquismo son factores que han demostrado una estrecha correlación con el riesgo de desarrollar cáncer de mama. Y aunque estas condiciones pueden afectar distintos niveles de regulación celular, el estudio de sus efectos en los mecanismos de regulación transcripcional y epigenética, es considerado fundamental para un mayor entendimiento de la pérdida de identidad de las células epiteliales durante la carcinogénesis de este tejido. El objetivo principal de esta revisión fue establecer la importancia de los cambios que ocurren a nivel transcripcional en la glándula mamaria, como consecuencia de una exposición aguda o crónica a productos nocivos, tales como los alimentos que favorecen la obesidad, el etanol y los componentes del humo del cigarro. Al analizar los principales estudios relacionados con el tema, se ha llegado a la conclusión de que la comprensión de los efectos causados por los factores de estilo de vida sobre el desempeño de los mecanismos de regulación transcripcional responsables de la expresión génica de las células epiteliales de la glándula mamaria, pueden ayudar a explicar el desarrollo de esta enfermedad en las mujeres que no son genéticamente propensas así como las diferentes manifestaciones fenotípicas de este tipo de cáncer.

The gonadotropin-releasing hormone system: Perspectives from reproduction to cancer (Review).

Recently, an increasing amount of evidence indicates that human gonadotropin-releasing hormone (hGnRH) and its receptor (hGnRHR) are important regulatory components not only to the reproduction process but also in the regulation of some cancer cell functions such as cell proliferation, in both hormone-dependent and -independent types of tumors. The hGnRHR is a naturally misfolded protein that is retained mostly in the endoplasmic reticulum; however, this mechanism can be overcome by treatment with several pharmacoperones, therefore, increasing the amount of receptors in the cell membrane. In addition, several reports indicate that the expression level of hGnRHR in tumor cells is even lower than in pituitary or gonadotrope cells. The signal transduction pathways activated by hGnRH in both gonadotrope and different cancer cell types are described in the present review. We also discuss how the rescue of misfolded receptors in tumor cells could be a promising strategy for cancer therapy.

Gonadotropin-releasing hormone receptor activates GTPase RhoA and inhibits cell invasion in the breast cancer cell line MDA-MB-231.

BACKGROUND: Gonadotropin-releasing hormone (GnRH) and its receptor (GnRHR) are both expressed by a number of malignant tumors, including those of the breast. In the latter, both behave as potent inhibitors of invasion. Nevertheless, the signaling pathways whereby the activated GnRH/GnRHR system exerts this effect have not been clearly established. In this study, we provide experimental evidence that describes components of the mechanism(s) whereby GnRH inhibits breast cancer cell invasion. METHODS: Actin polymerization and substrate adhesion was measured in the highly invasive cell line, MDA-MB-231 transiently expressing the wild-type or mutant DesK191 GnRHR by fluorometry, flow cytometric analysis, and confocal microscopy, in the absence or presence of GnRH agonist. The effect of RhoA-GTP on stress fiber formation and focal adhesion assembly was measured in MDA-MB-231 cells co-expressing the GnRHRs and the GAP domain of human p190Rho GAP-A or the dominant negative mutant GAP-Y1284D. Cell invasion was determined by the transwell migration assay. RESULTS: Agonist-stimulated activation of the wild-type GnRHR and the highly plasma membrane expressed mutant GnRHR-DesK191 transiently transfected to MDA-MB-231 cells, favored F-actin polymerization and substrate adhesion. Confocal imaging allowed detection of an association between F-actin levels and the increase in stress fibers promoted by exposure to GnRH. Pull-down assays showed that the effects observed on actin cytoskeleton resulted from GnRH-stimulated activation of RhoA GTPase. Activation of this small G protein favored the marked increase in both cell adhesion to Collagen-I and number of focal adhesion complexes leading to inhibition of the invasion capacity of MDA-MB-231 cells as disclosed by assays in Transwell Chambers. CONCLUSIONS: We here show that GnRH inhibits invasion of highly invasive breast cancer-derived MDA-MB-231 cells. This effect is mediated through an increase in substrate adhesion promoted by activation of RhoA GTPase and formation of stress fibers and focal adhesions. These observations offer new insights into the molecular mechanisms whereby activation of overexpressed GnRHRs affects cell invasion potential of this malignant cell line, and provide opportunities for designing mechanism-based adjuvant therapies for breast cancer.

[Lymphatic mapping and sentinel lymph node biopsy in patients with high risk squamous cell carcinoma of the skin]. / Mapeo linfático y biopsia del ganglio centinela en pacientes con carcinoma epidermoide cutáneo de alto riesgo.

BACKGROUND: Some sub-groups of cutaneous squamous cell carcinoma (CSCC) display a higher risk for regional metastasis. Sentinel lymph node staging has been used successfully to evaluate nodal metastasis in selective tumors. OBJECTIVE: Assess the feasibility of sentinel node to detect occult regional lymph node metastasis in high-risk CSCC. MATERIAL AND METHODS: Between January 2002 and March 2004, a total of 20 patients received pre-operative lymphoscintigraphy and sentinel lymphadenectomy for high-risk CSCC with clinically non-palpable regional lymph nodes. RESULTS: In one of each 5 patients (20%), sentinel lymph node showed histological evidence of microinvolvement. No patients with negative sentinel node showed tumor dissemination during follow-up, with a mean of 23.5 months (range 7-44). CONCLUSIONS: Sentinel lymph node biopsy is technically feasible with low morbidity. Sentinel lymphadenectomy may play an important role in the management of high-risk CSCC with clinically non-palpable regional lymph nodes. This technique can help identify patients with regional lymph node metastases who may benefit from complete lymphadenectomy. This improved staging may allow clinicians to better stratify patients who might benefit from adjuvant therapy.

Mapeo linfático y biopsia del ganglio centinela en pacientes con carcinoma epidermoide cutáneo de alto riesgo / Lymphatic mapping and sentinel lymph node biopsy in patients with high risk squamous cell carcinoma of the skin

Introducción: Un subgrupo de pacientes con carcinoma epidermoide cutáneo (CEC) tiene alto riesgo de presentar metástasis ganglionares regionales. El mapeo linfático y biopsia del ganglio centinela (MLBGC) ha sido exitosamente utilizado para evaluar la presencia de metástasis ganglionares subclínicas en diversos tumores. bjetivo: Evaluar la utilidad de la técnica del MLBGC en los pacientes con CEC de alto riesgo para detectar la presencia de metástasis ganglionares regionales subclínicas. Material y métodos: De enero 2002 a marzo 2004, un total de 20 pacientes con CEC de alto riesgo con ganglios linfáticos regionales clínicamente no palpables fue evaluado con linfografía preoperatoria y MLBGC. Resultados: En 1 de cada 5 pacientes (20 %), el ganglio centinela reveló la presencia de micrometástasis. Ningún paciente con GC negativo manifestó progresión tumoral ganglionar regional durante un seguimiento medio de 23.5 meses (rango de 7 a 44 meses). Conclusiones: El MLBGC fue técnicamente posible con baja morbilidad. El MLBGC puede tener un importante papel en el tratamiento de los pacientes con CEC de alto riesgo con ganglios linfáticos regionales no palpables. Esta técnica puede ayudar a identificar los pacientes con metástasis en los ganglios linfáticos regionales que pueden beneficiarse de una disección ganglionar radical. Además provee importante información para utilizar terapias adyuvantes a la cirugía.

BACKGROUND: Some sub-groups of cutaneous squamous cell carcinoma (CSCC) display a higher risk for regional metastasis. Sentinel lymph node staging has been used successfully to evaluate nodal metastasis in selective tumors. OBJECTIVE: Assess the feasibility of sentinel node to detect occult regional lymph node metastasis in high-risk CSCC. MATERIAL AND METHODS: Between January 2002 and March 2004, a total of 20 patients received pre-operative lymphoscintigraphy and sentinel lymphadenectomy for high-risk CSCC with clinically non-palpable regional lymph nodes. RESULTS: In one of each 5 patients (20%), sentinel lymph node showed histological evidence of microinvolvement. No patients with negative sentinel node showed tumor dissemination during follow-up, with a mean of 23.5 months (range 7-44). CONCLUSIONS: Sentinel lymph node biopsy is technically feasible with low morbidity. Sentinel lymphadenectomy may play an important role in the management of high-risk CSCC with clinically non-palpable regional lymph nodes. This technique can help identify patients with regional lymph node metastases who may benefit from complete lymphadenectomy. This improved staging may allow clinicians to better stratify patients who might benefit from adjuvant therapy.

Transcriptional regulation of the GnRH receptor gene by glucocorticoids.

Expression of the gonadotropin-releasing hormone (GnRH) receptor gene is stimulated by dexamethasone in GnRH-deficient rodents. In this study we identify a 1226 bp sequence at the 5'-flanking region of the mouse GnRH-R gene that confers dexamethasone responsiveness when expressed in host cells. Further, a glucocorticoid antagonist blocks transcriptional activity of the mGnRHR promoter. Progressive 5'-deletion of the mGnRHR promoter localized the response sequence between the -331/-255 region. Analysis of this region revealed binding sites for the AP-1 transcription factor. Mutation in AP-1 modified the functional activity of the mGnRHR promoter following GnRH agonist or dexamethasone-stimulation. Using an electrophoretic mobility shift assay, a protein complex is shown to bind to the AP-1 site. These results suggest that AP-1 proteins and glucocorticoid receptor regulate transcription of the GnRH-R promoter in a heterologous system.