Laurencia johnstonii extract reverses early lesions in the K14E7HPV16 murine cervical carcinogenesis model.

Persistent infection with high-risk human papillomavirus (HR-HPV) is a well-established risk factor to the development of cervical intraepithelial neoplasia (CIN), a condition that can progress to cervical cancer (CC) a major health problem worldwide. Recently, there has been growing interest in exploring alternative therapies utilizing natural products, among which is the algae species Laurencia johnstonii Setchell & Gardner, 1924 (L. johnstonii), proposed for the management of precancerous lesions. The aim of this work was to determine the effect of an organic extract from L. johnstonii (ELj) in early cervical lesions (CIN 1). These CIN 1 lesions were generated in a murine model expressing the HR-HPV16 E7 oncoprotein (K14E7HPV transgenic mice) with a single exogenous hormonal stimulus using 17ß-estradiol. The histopathological studies, the determination of cell proliferation and of the apoptotic levels in cervical tissue, showed that, seven doses of ELj (30 mg/kg weight per day diluted in a DMSO-saline solution [1:7]) lead to recovery the architecture of cervical epithelium. Accordingly, in the transgenic mice it was observed a statistically significant decrease of the PCNA expression levels, a marker of cell proliferation, and a statistically significant increase in the apoptosis levels using Caspase 3 as a marker. In addition, we determined the expression levels of the tumor suppressor miR-218 and the oncomiRNA miR-21. Interestingly, our results may suggest that ELj treatment tended to restore the normal expression of both miRNAs as compared with controls being more evident in the non-transgenic induced mice. Differences of p < 0.05 were considered statistically significant through the whole study. Based on these results, we propose that the use of ELj could be an alternative for the treatment of cervical early lesions.

Ion Channels as Potential Tools for the Diagnosis, Prognosis, and Treatment of HPV-Associated Cancers.

The human papilloma virus (HPV) group comprises approximately 200 genetic types that have a special affinity for epithelial tissues and can vary from producing benign symptoms to developing into complicated pathologies, such as cancer. The HPV replicative cycle affects various cellular and molecular processes, including DNA insertions and methylation and relevant pathways related to pRb and p53, as well as ion channel expression or function. Ion channels are responsible for the flow of ions across cell membranes and play very important roles in human physiology, including the regulation of ion homeostasis, electrical excitability, and cell signaling. However, when ion channel function or expression is altered, the channels can trigger a wide range of channelopathies, including cancer. In consequence, the up- or down-regulation of ion channels in cancer makes them attractive molecular markers for the diagnosis, prognosis, and treatment of the disease. Interestingly, the activity or expression of several ion channels is dysregulated in HPV-associated cancers. Here, we review the status of ion channels and their regulation in HPV-associated cancers and discuss the potential molecular mechanisms involved. Understanding the dynamics of ion channels in these cancers should help to improve early diagnosis, prognosis, and treatment in the benefit of HPV-associated cancer patients.

Ion Channels and Personalized Medicine in Gynecological Cancers.

Targeted therapy against cancer plays a key role in delivering safer and more efficient treatments. In the last decades, ion channels have been studied for their participation in oncogenic processes because their aberrant expression and/or function have been associated with different types of malignancies, including ovarian, cervical, and endometrial cancer. The altered expression or function of several ion channels have been associated with tumor aggressiveness, increased proliferation, migration, invasion, and metastasis of cancer cells and with poor prognosis in gynecological cancer patients. Most ion channels are integral membrane proteins easily accessible by drugs. Interestingly, a plethora of ion channel blockers have demonstrated anticancer activity. Consequently, some ion channels have been proposed as oncogenes, cancer, and prognostic biomarkers, as well as therapeutic targets in gynecological cancers. Here, we review the association of ion channels with the properties of cancer cells in these tumors, which makes them very promising candidates to be exploited in personalized medicine. The detailed analysis of the expression pattern and function of ion channels could help to improve the clinical outcomes in gynecological cancer patients.

Global expression profiling of CD10 + /CD19 + pre-B lymphoblasts from Hispanic B-ALL patients correlates with comparative TARGET database analysis.

Mexico City has one of the highest incidences of acute lymphoblastic leukemia (ALL) globally, with patients showing low survival, and high relapse rates. To gain more insight into the molecular features of B-ALL in Mexican children, we isolated CD10 + /CD19 + precursor B lymphoblasts from four bone marrow and nine peripheral blood samples of B-ALL patients using a fluorescence-activated cell sorting protocol. The global gene expression profile (BM vs PB) revealed 136 differentially expressed genes; 62 were upregulated (45.6%) and 74 were downregulated (54.4%). Pearson's correlation coefficient was calculated to determine the similarity between pre-B lymphoblast populations. We selected 26 highly significant genes and validated 21 by RT-qPCR (CNN3, STON2, CALN1, RUNX2, GADD45A, CDC45, CDC20, PLK1, AIDA, HCK, LY86, GPR65, PIK3CG, LILRB2, IL7R, TCL1A, DOCK1, HIST1H3G, PTPN14, CD72, and NT5E). The gene set enrichment analysis of the total expression matrix and the ingenuity pathway analysis of the 136 differentially expressed genes showed that the cell cycle was altered in the bone marrow with four overexpressed genes (PLK1, CDC20, CDC45, and GADD45A) and a low expression of IL7R and PIK3CG, which are involved in B cell differentiation. A comparative bioinformatics analysis of 15 bone marrow and 10 peripheral blood samples from Hispanic B-ALL patients collected by the TARGET program, corroborated the genes observed, except for PIK3CG. We conclude the Mexican and the Hispanic B-ALL patients studied present common driver alterations and histotype-specific mutations that could facilitate risk stratification and diagnostic accuracy and serve as potential therapeutic targets.

Vitamin A deficiency in K14E7HPV expressing transgenic mice facilitates the formation of malignant cervical lesions.

Infection with high-risk human papillomavirus (HR-HPV) is the main cause of cervical cancer (CC), but viral infection alone does not guarantee the development of this malignancy. Indeed, deficiencies of dietary micronutrients could favor cervical cancer development in individuals that harbor HR-HPV infections. The status of retinoid levels, natural and synthetic derivatives of vitamin A, is important in maintaining cellular differentiation of the cervical epithelium. Moreover, many studies show a link between deficient intake of retinoids or alteration of the retinoid receptors and CC development. In spite of this, the effect of vitamin A deficiency (VAD) in presence of HR-HPV oncoproteins on cervical carcinogenesis in vivo has not been reported. Transgenic mice expressing E6 or E7 oncoproteins (K14E6 or K14E7 mice, respectively) were used to evaluate the possible role of VAD in the development of malignant cervical lesions. The survival of the mice in VAD condition was studied, and histopathological analysis and immunohistochemical detection of molecular cancer markers such as the tumor suppressor retinoic acid receptor beta (RARß), proliferating cell nuclear antigen (PCNA), cleaved caspase 3, and the tumor suppressor protein p16INK4A (inhibitor of CDK4) were performed. Our results show that K14E6/VAD mice showed moderate cervical dysplasia; notably, K14E7/VAD mice developed severe cervical dysplasia and cervical in situ carcinoma at an early age. VAD synergizes with HPV16E7 oncoprotein expression favoring cervical carcinogenesis in vivo.

Expression of miR-34a and miR-15b during the progression of cervical cancer in a murine model expressing the HPV16 E7 oncoprotein.

The high-risk human papillomavirus (HR-HPV) E7 oncoprotein appears to be a major determinant for cell immortalization and transformation altering critical processes such as cell proliferation, apoptosis, and immune response. This oncoprotein plays an essential role in cervical carcinogenesis, but other cofactors such as long-term use of hormonal contraceptives are necessary to modulate the risk of cervical cancer (CC). The role of HR-HPVs in the alteration of microRNA (miRNA) levels in persistent viral infections currently remains unclear. The aim of this study was to evaluate the miR-34a and miR-15b expression levels in the murine HPV16K14E7 (K14E7) transgenic model after chronic estrogen (E2) treatment and their involvement in CC. Interestingly, results showed that, although miR-34a expression is elevated by the HPVE7 oncogene, this expression was downregulated in the presence of both the E7 oncoprotein and chronic E2 in cervical carcinoma. On the other hand, miR-15b expression was upregulated along cervical carcinogenesis mainly by the effect of E2. These different changes in the expression levels of miR-34a and miR-15b along cervical carcinogenesis conduced to low apoptosis levels, high cell proliferation and finally, to cancerous cervical tissue development. In this work, we also determined the relative mRNA expression of Cyclin E2 (Ccne2), Cyclin A2 (Ccna2), and B cell lymphoma 2 (Bcl-2) (target genes of miR-34a and miR-15b); Sirtuin 1 (Sirt1), Cmyc, and Bax (miR-34a target genes); and p21/WAF1 (mir15b target gene) and the H-ras oncogene. Given the modifications in the expression levels of miR-34a and miR-15b during the development of cervical cancer, it will be useful to carry out further investigation to confirm them as molecular biomarkers of cancer.

Circulating miR-15b, miR-34a and miR-218 as promising novel early low-invasive biomarkers of cervical carcinogenesis.

Circulating biological markers, such as miRNAs, hold the greatest possibilities to complement tissue biopsy and clinical diagnostic tests. The objective of this study was to evaluate the relative abundance of three circulating miRNAs in serum from 17 HPV16-positive patients with early cervical lesions known as Low-Grade Squamous Intraepithelial Lesions (LSILs). The expression of circulating microRNAs miR-15b, miR-34a and miR-218 in patients with LSILs was compared to 23 HPV-negative individuals showing normal cervical epithelium (healthy women) and 23 Squamous Cell Carcinoma (SCC) samples. The expression levels of miR-15b remained unchanged while those of miRNAs 34a and 218 were relatively high in serum obtained from LSIL patients in comparison with healthy women (results were statistically significant with a p of < 0.01 or < 0.001). According to previous findings, miR-15b was overexpressed and miRNAs 34a and 218 were underexpressed in serum from SCC patients. Additionally, the mRNA expression levels of some selected gene targets were determined [Cyclin D1 (CCND1), Cyclin E1 (CCNE1), B-cell lymphoma 2 (Bcl-2) and MutS homolog 2 (MSH-2)]. All serum results correlated with tissue samples from the same patients. We propose that circulating microRNAs can be valuable as molecular markers for the early follow-up of cervical carcinogenesis risk.

E7 oncoprotein from human papillomavirus 16 alters claudins expression and the sealing of epithelial tight junctions.

Tight junctions (TJs) are cell­cell adhesion structures frequently altered by oncogenic transformation. In the present study the role of human papillomavirus (HPV) 16 E7 oncoprotein on the sealing of TJs was investigated and also the expression level of claudins in mouse cervix and in epithelial Madin­Darby Canine Kidney (MDCK) cells. It was found that there was reduced expression of claudins ­1 and ­10 in the cervix of 7­month­old transgenic K14E7 mice treated with 17ß­estradiol (E2), with invasive cancer. In addition, there was also a transient increase in claudin­1 expression in the cervix of 2­month­old K14E7 mice, and claudin­10 accumulated at the border of cells in the upper layer of the cervix in FvB mice treated with E2, and in K14E7 mice treated with or without E2. These changes were accompanied by an augmented paracellular permeability of the cervix in 2­ and 7­month­old FvB mice treated with E2, which became more pronounced in K14E7 mice treated with or without E2. In MDCK cells the stable expression of E7 increased the space between adjacent cells and altered the architecture of the monolayers, induced the development of an acute peak of transepithelial electrical resistance accompanied by a reduced expression of claudins ­1, ­2 and ­10, and an increase in claudin­4. Moreover, E7 enhances the ability of MDCK cells to migrate through a 3D matrix and induces cell stiffening and stress fiber formation. These observations revealed that cell transformation induced by HPV16 E7 oncoprotein was accompanied by changes in the pattern of expression of claudins and the degree of sealing of epithelial TJs.

Genes Involved in the Transcriptional Regulation of Pluripotency Are Expressed in Malignant Tumors of the Uterine Cervix and Can Induce Tumorigenic Capacity in a Nontumorigenic Cell Line.

Transcription factors OCT4, SOX2, KLF4, C-MYC, and NANOG (OSKM-N) regulate pluripotency and stemness, and their ectopic expression reprograms human and murine fibroblasts that constitute the key of regenerative medicine. To determine their contribution to cell transformation, we analyzed the gene expression profiles of these transcription factors in cervical cancer samples and found that they are preferentially expressed in the tumor component. Also, cancer stem cell-enriched cultures grown as sphere cultures showed overexpression of OSKM-N genes. Importantly, we observed that lentiviral-mediated transduction of these factors confers, to a nontumorigenic immortalized human cell line, properties of cancer stem cells as the ability to form tumors in a mouse model. When we performed a meta-analysis using microarray data from cervical cancer biopsies and normal tissues, we found that the expression of OSKM-N and some target genes allowed separating tumor and normal tissues between samples, which enhanced the importance of OSKM-N in the tumorigenesis. Finally, we analyzed and compared both transcript and protein expression profiles of these factors within a cohort of patients with cervical cancer. To our knowledge, this is the first time that the expression of OSKM-N is described to induce one of the main characteristics of the cancer stem cell, the tumorigenicity. And, more importantly, its exogenous expression in a nontumorigenic cell line is sufficient to induce a tumorigenic phenotype; furthermore, the differential expression of this transcription factor distinguishes tumor tissue and normal tissue in cervical samples.

Association between HPV infection and prostate cancer in a Mexican population.

The aim of this study was to evaluate the association between prostate cancer (PCa) and Human papillomavirus (HPV) infection in the Mexican population. We studied 356 paraffin-embedded tissues from unrelated Mexican men with PCa or benign prostatic hyperplasia (BPH), with the latter serving as control. HPV detection was performed by polymerase chain reaction (PCR) using universal primers, and viral genotypes were detected using sequencing or multiplex PCR. Light microscopy analyses enabled the identification of koilocytes in samples subsequently analyzed for HPV detection by in situ PCR and for p16-INK4A expression by immunohistochemistry. The results showed that high risk- (HR) HPVs were detected in 37/189 (19.6%) PCa specimens compared to 16/167 (9.6%) of BHP specimens (odds ratio 2.3; 95% CI= 1.2 to 4.3; p=0.01). These data suggest HR-HPV may play a role in PCa. HPV 52 and 58 were the most frequent genotypes (33 and 17%, respectively) detected in the population studied. Koilocytes were detected in all in situ PCR-HPV-positive samples, representing a pathognomonic feature of infection, and we observed the overexpression of p16-INK4A in HPV-positive samples compared to HPV-negative samples, indirectly suggesting the presence of HR-HPV E7 oncoprotein. These results suggest that HPV infection plays an important role in prostate cancer development.

HPV16-E6 Oncoprotein Activates TGF-ß and Wnt/ß-Catenin Pathways in the Epithelium-Mesenchymal Transition of Cataracts in a Transgenic Mouse Model.

OBJECTIVE: This work aimed to determine if cataractous changes associated with EMT occurring in the K14E6 mice lenses are associated with TGF-ß and Wnt/ß-catenin signaling activation. MATERIALS AND METHODS: Cataracts of K14E6 mice were analysed histologically; and components of TGF-ß and Wnt/ß-catenin signaling were evaluated by Western blot, RT-qPCR, in situ RT-PCR, IHC, or IF technics. Metalloproteinases involved in EMT were also assayed using zymography. The endogenous stabilisation of Smad7 protein was also assessed using an HDAC inhibitor. RESULTS: The K14E6 mice, which displayed binocular cataracts in 100% of the animals, exhibited loss of tissue organisation, cortical liquefaction, and an increase in the number of hyperproliferative-nucleated cells with mesenchymal-like characteristics in the lenses. Changes in lenses' cell morphology were due to actin filaments reorganisation, activation of TGF-ß and Wnt/ß-catenin pathways, and the accumulation of MTA1 protein. Finally, the stabilisation of Smad7 protein diminishes cell proliferation, as well as MTA1 protein levels. CONCLUSION: The HPV16-E6 oncoprotein induces EMT in transgenic mice cataracts. The molecular mechanism may involve TGF-ß and Wnt/ß-catenin pathways, suggesting that the K14E6 transgenic mouse could be a useful model for the study or treatment of EMT-induced cataracts.

The HPV16 E7 Oncoprotein Disrupts Dendritic Cell Function and Induces the Systemic Expansion of CD11b(+)Gr1(+) Cells in a Transgenic Mouse Model.

Objective. The aim of this study was to analyze the effects of the HPV16 E7 oncoprotein on dendritic cells (DCs) and CD11b(+)Gr1(+) cells using the K14E7 transgenic mouse model. Materials and Methods. The morphology of DCs was analyzed in male mouse skin on epidermal sheets using immunofluorescence and confocal microscopy. Flow cytometry was used to determine the percentages of DCs and CD11b(+)Gr1(+) cells in different tissues and to evaluate the migration of DCs. Results. In the K14E7 mouse model, the morphology of Langerhans cells and the migratory activity of dendritic cells were abnormal. An increase in CD11b(+)Gr1(+) cells was observed in the blood and skin of K14E7 mice, and molecules related to CD11b(+)Gr1(+) chemoattraction (MCP1 and S100A9) were upregulated. Conclusions. These data suggest that the HPV16 E7 oncoprotein impairs the function and morphology of DCs and induces the systemic accumulation of CD11b(+)Gr1(+) cells.

The expression of miR-21 and miR-143 is deregulated by the HPV16 E7 oncoprotein and 17ß-estradiol.

MicroRNAs (miRNAs) are a class of non-coding RNAs that negatively regulate their target mRNAs at a posttranscriptional level, thereby affecting crucial processes in cancer development. However, little is known about the molecular events that control expression of miRNAs in cervical cancer (CC). HPV16 E7 oncoprotein in conjunction with estrogen are sufficient to produce high grade cervical dysplasia and invasive cervical malignancies in a mouse model. In the present study, we determined the potential role that the E7 oncoprotein and 17ß-estradiol (E2) play in the deregulation of miR-21 and miR-143 expression levels by these two risk factors. We found that, while the expression of miR-21 was upregulated and the expression of miR-143 was downregulated by the HPV16 E7 oncoprotein in vivo, and in vitro and that E2 treatment is also implicated in the deregulation of these important miRNAs in vivo. Sustained upregulation of miR-21 resulted in suppression of PTEN expression, and repression of miR-143 increased the mRNA and protein levels from Bcl-2. These results suggested that HPV type 16 E7 oncoprotein and E2 play an important role in regulating miR-21 and miR-143 expression. We have observed similar results in CC patients containing HPV16 sequences, suggesting that these miRNAs could serve as diagnostic biomarkers in CC. The present study highlights the roles of miRNAs in cervical tissue and implicates these important molecules in cervical carcinogenesis.

Clinical relevance of the fusion transcripts distribution pattern in mexican children with acute lymphoblastic leukemia.

Chromosomal translocation-generated fusion genes in childhood acute lymphoblastic leukemia (ALL) are well-known indicators of prognostic outcome. This study was conducted to establish the clinical relevance of the fusion genes distribution pattern in Mexican children with newly diagnosed ALL. Multiplex RT-PCR assays were used to detect 4 commonest fusion transcripts in 261 Mexican children with B-cell precursor ALL aged 1 to 14 years old, comparing differences in the distribution of the patients between molecular subgroups to a common collection of clinical parameters. We documented a 13% significant proportion of all patients who are more than 10 years of age, harboring fusion transcripts associated with leukocytosis and poor response to remission-induction chemotherapy, than those negative children for chimeric transcripts (P<0.001). Most notable observation was identified a significant number of e2a-pbx1-positive patients who showed a more aggressive disease at diagnosis. As presented here, this report gives an overview of the clinical implications of the fusion gene positivity in Mexican children with ALL in the context of traditional risk stratification variables. Our data support the existence of important ethnic and geographic differences in Mexican population.

In situ molecular identification of the influenza A (H1N1) 2009 Neuraminidase in patients with severe and fatal infections during a pandemic in Mexico City.

BACKGROUND: In April 2009, public health surveillance detected an increased number of influenza-like illnesses in Mexico City's hospitals. The etiological agent was subsequently determined to be a spread of a worldwide novel influenza A (H1N1) triple reassortant. The purpose of the present study was to demonstrate that molecular detection of pandemic influenza A (H1N1) 2009 strains is possible in archival material such as paraffin-embedded lung samples. METHODS: In order to detect A (H1N1) virus sequences in archived biological samples, eight paraffin-embedded lung samples from patients who died of pneumonia and respiratory failure were tested for influenza A (H1N1) Neuraminidase (NA) RNA using in situ RT-PCR. RESULTS: We detected NA transcripts in 100% of the previously diagnosed A (H1N1)-positive samples as a cytoplasmic signal. No expression was detected by in situ RT-PCR in two Influenza-like Illness A (H1N1)-negative patients using standard protocols nor in a non-related cervical cell line. In situ relative transcription levels correlated with those obtained when in vitro RT-PCR assays were performed. Partial sequences of the NA gene from A (H1N1)-positive patients were obtained by the in situ RT-PCR-sequencing method. Sequence analysis showed 98% similarity with influenza viruses reported previously in other places. CONCLUSIONS: We have successfully amplified specific influenza A (H1N1) NA sequences using stored clinical material; results suggest that this strategy could be useful when clinical RNA samples are quantity limited, or when poor quality is obtained. Here, we provide a very sensitive method that specifically detects the neuraminidase viral RNA in lung samples from patients who died from pneumonia caused by Influenza A (H1N1) outbreak in Mexico City.

Retinoic acid receptor ß deficiency reduces splenic dendritic cell population in a conditional mouse line.

Different studies have shown that retinoids and their receptors [retinoic acid receptors (RARs) and retinoid X receptors (RXRs)] have crucial effects on the differentiation and function of myeloid cells such as Dendritic cells (DCs) and the development of lymphoid tissue. However, the relationship between RARß expression and DCs has not been previously studied in vivo. This work examined the effect of decreased RARß expression on the number (and probably on differentiation) of splenic DCs and the structure of spleen using a conditional mouse that partially ablates floxed RARß gene (RARß(L-/L-) mice). Our results showed that RARß is expressed mainly in cells of the splenic White Pulp (WP) zone of Wild type mice. As expected, low levels of RARß expression were detected in the spleen of RARß(L-/L-) conditional mice. These results were consistent with a decrease in the population of splenic CD11c(+)MHC-II(+) cells. Histopathological analyses of conditional mice spleen indicated defects in cell organization and structure. The expression of Toll-like receptor 2 was also down-regulated in the spleen of these mice. These results suggest that RARß is involved in splenic cell organization as well as in the maintenance of splenic DCs population, indicating that RARß expression is important in homeostasis of immune system components.

RXRα deletion and E6E7 oncogene expression are sufficient to induce cervical malignant lesions in vivo.

Cervical cancer is the second leading cause of cancer deaths among women worldwide. High-Risk-Human Papillomaviruses (HR-HPVs) play an important etiologic role in the development of carcinoma of the uterine cervix. However, host factors are important in determining the outcome of genital HPV infection as most cervical precancerous lesions containing HR-HPVs do not progress to invasive carcinomas. Retinoids, acting through nuclear receptors (RARs, RXRs), play a crucial role in cervix development and homeostasis regulating growth and differentiation of a wide variety of cell types; indeed, they can inhibit cell proliferation, and induce cell differentiation or apoptotic cell death. Here we introduce a mouse model that develops spontaneously malignant cervical lesions allowing the study of the cooperative effect between HPV16E6E7 expression and the lack of RXRα in cervical cancer development. This model could be useful to study multistep carcinogenesis of uterine cervix tissue and might improve chemopreventive and chemotherapeutic strategies for this neoplasia.

Entamoeba histolytica calreticulin: an endoplasmic reticulum protein expressed by trophozoites into experimentally induced amoebic liver abscesses.

Entamoeba histolytica calreticulin (EhCRT) is remarkably immunogenic in humans (90-100% of invasive amoebiasis patients). Nevertheless, the study of calreticulin in this protozoan is still in its early stages. The exact location, biological functions, and its role in pathogenesis are yet to be fully understood. The aim of the present work is to determine the location of EhCRT in virulent trophozoites in vivo and the expression of the Ehcrt gene during the development of experimentally induced amoebic liver abscesses (ALA) in hamsters. Antibodies against recombinant EhCRT were used for the immunolocalization of EhCRT in trophozoites through confocal microscopy; immunohistochemical assays were also performed on tissue sections of ALAs at different times after intrahepatic inoculation. The expression of the Ehcrt gene during the development of ALA was estimated through both in situ RT-PCR and real-time RT-PCR. Confocal assays of virulent trophozoites showed a distribution of EhCRT in the cytoplasmic vesicles of different sizes. Apparently, EhCRT is not exported into the hepatic tissue. Real-time RT-PCR demonstrated an over-expression of the Ehcrt gene at 30 min after trophozoite inoculation, reaching a peak at 1-2 h; thereafter, the expression fell sharply to its original levels. These results demonstrate for the first time in an in vivo model of ALA, the expression of Ehcrt gene in E. histolytica trophozoites and add evidence that support CRT as a resident protein of the ER in E. histolytica species. The in vivo experiments suggest that CRT may play an important role during the early stages of the host-parasite relationship, when the parasite is adapting to a new environment, although the protein seems to be constitutively synthesized. Moreover, trophozoites apparently do not export EhCRT into the hepatic tissue in ALA.

Induction of focal epithelial hyperplasia in tongue of young bk6-E6/E7 HPV16 transgenic mice.

Squamous cell carcinoma (SCC) of the oral cavity is one of the most common neoplasms in the world. During the past 2 decades, the role of high-risk human papilloma virus (HR-HPV) has been studied and the data supporting HPV as a one of the causative agents in the development and progression of a sub-set of head and neck squamous cell carcinomas (HNSCC) has accumulated. In order to investigate the role of HR-HPV oncogene expression in early epithelial alterations in vivo, we produced transgenic mice expressing HPV16 early region genes from the promoter of the bovine keratin 6 gene (Tg[bK6-E6/E7]). In this article, we demonstrate that E6/E7 transgene was abundantly expressed and cellular proliferation was increased in the middle tongue epithelia of transgenic mice, and that in the same region young (27 weeks old) Tg[bK6-E6/E7] mice spontaneously developed histological alterations, mainly focal epithelial hyperplasia (FEH).

Human papillomavirus E6/E7 oncogenes promote mouse ear regeneration by increasing the rate of wound re-epithelization and epidermal growth.

Mammals have limited regeneration capacity. We report here that, in transgenic mice (Tg(bK6-E6/E7)), the expression of the E6/E7 oncogenes of human papilloma virus type 16 (HPV16) under the control of the bovine keratin 6 promoter markedly improves the mouse's capacity to repair portions of the ear after being wounded. Increased repair capacity correlates with an increased number of epidermal proliferating cells. In concordance with the expected effects of the E6 and E7 oncogenes, levels of p53 decreased and those of p16 in epidermal cells increased. In addition, we observed that wound re-epithelization proceeded faster in transgenic than in wild-type animals. After the initial re-epithelization, epidermal cell migration from the intact surrounding tissue appears to be a major contributor to the growing epidermis, especially in the repairing tissue of transgenic mice. We also found that there is a significantly higher number of putative epidermal stem cells in Tg(bK6-E6/E7) than in wild-type mice. Remarkably, hair follicles and cartilage regenerated within the repaired ear tissue, without evidence of tumor formation. We propose that the ability to regenerate ear portions is limited by the capacity of the epidermis to repair itself and grow.