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R Sánchez-Prieto

Publications and source records attributed to R Sánchez-Prieto.

11 recordsLinked to original sources
PubMed2007

High prevalence of human papillomavirus 16 in penile carcinoma.

In order to analyze the incidence and prevalence of Human Papillomavirus (HPV) in penile carcinoma, we studied 49 patients with penile carcinoma. Formalin-fixed, paraffin-embedded tissue samples were collected from 64 samples of penile carcinoma from the Hospital General Universitario (Albacete, Spain). Cases were histologically classified and the polymerase chain reaction (PCR) method was used to detect the presence of HPV. Two sets of consensus primers were used, the My09/My11, and the GP5+/GP6+. All positive cases were sequenced in order to establish the implicated genotype. Our results showed that 38 of the 49 cases were positive for HPV (77,5%). HPV16 appeared in 32 (84,2 %) of the 38 positive cases and HPV18 in 4 (10,5%). Our data demonstrate that the My09/My11 primers are more sensitive than GP5+/GP6+ primers, although the combination of the two sets of primers notably increased the total number of HPV positive cases detected.

Carcinoma, Squamous Cell↗
PubMed2006

Adenovirus E1A orchestrates the urokinase-plasminogen activator system and upregulates PAI-2 expression, supporting a tumor suppressor effect.

Invasiveness and metastatic potential are the two most important properties defining malignancy. The adeno-virus E1A (Ad-E1A) gene has a dual effect as a proliferative gene and as a tumor-suppressor gene, decreasing tumor growth and the metastatic potential of malignant cells. In order to study genes related with the antimetastatic effect of Ad-E1A in human cells, we performed a microarray analysis using OncoChiptrade mark. In three independent experiments, NIH3T3, IMR90 and MDA MB 435 cells were infected with pLPC retroviruses carrying the adenovirus 12S E1A gene or the GFP gene. We analyzed cDNA expression by using the CNIO OncoChipTM, a cDNA microarray containing a total of 6386 genes represented by 7237 clones. uPA, uPAr, tPA, PAI-1 and PAI-2 were also studied at RNA and protein levels. Microarrays of cDNA expression, RT-PCR and Western blot performed in IMR90 E1A-expressing cells showed downregulation of uPA, uPAr, tPA, PAI-1 and upregulation of PAI-2. These results were confirmed in NIH3T3 and MDA MB 435 breast carcinoma cells, with PAI-2 upregulation by RT-PCR and Western blot. In addition, zymographic analysis demonstrated that E1A expression greatly reduced the gelatinase activity of the pro-MMP2 and -MMP9 proteins. We propose that adenovirus E1A may orchestrate the expression of most members of the urokinase-plasminogen activation system, downregulating potentially invasive genes and upregulating PAI-2, which is associated with a better prognosis in human tumors.

Adenoviridae↗
PubMed2005

The calcium-binding protein calretinin is a marker of the companion cell layer of the human hair follicle.

BACKGROUND: Ultrastructural studies of the hair follicle show that the outer root sheath (ORS) does not consist of a homogeneous cell population. The innermost cell layer of the ORS, also called the companion layer, is a single cell layer closely associated with the Henle layer of the inner root sheath. OBJECTIVES: To describe the immunohistochemical expression of calretinin, a calcium-binding protein, in the human hair follicle. METHODS: Immunohistochemical studies using two different antisera to calretinin were performed in paraffin-embedded and in frozen scalp specimens using standard techniques. RESULTS: Calretinin immunostaining was consistently and specifically found in the companion cell layer of hair follicles. CONCLUSIONS: These findings provide further evidence to support the notion that the companion layer is not only morphologically, but also immunohistochemically, different from the other cells of the ORS.

Aged↗
PubMed1999

In vivo radiosensitizing effect of the adenovirus E1A gene in murine and human malignant tumors.

The adenovirus E1A gene is a potent inducer of chemosensitivity and radiosensitivity through p53-dependent and independent mechanisms. We have studied the sensitivity of murine (MSC11A5, a sarcomatoid epidermoid carcinoma) and human (HeLa, human cervix carcinoma) E1A-expressing tumors, in vivo, after treatment with cisplatin or gamma-irradiation. In athymic mice, half-body irradiation was performed in an AECL Cobalt unit, at an SSD of 80 cm. Daily fractions of 300 cGy over 3 days, up to a total dose of 9 Gy. Cisplatin was injected intraperitoneally at a dose of 9 mg per kg of body weight. After gamma-irradiation or intraperitoneal injection of cisplatin, about 30% of the E1A-expressing tumors regressed completely or were associated with a marked decrease in tumorigenicity over the following weeks. We conclude that malignant tumors, when expressing adenovirus E1A, are very sensitive to treatment with DNA-damaging agents, in vivo, regardless of the p53 status of the tumors.

Adenovirus E1A Proteins↗
PubMed1998

Microsatellite instability and p53 mutations in sporadic right and left colon carcinoma: different clinical and molecular implications.

BACKGROUND: Left and right colon carcinomas can display different clinical, pathologic, and genetic characteristics. The purpose of this study was to characterize multiple molecular genetic alterations in sporadic colon carcinoma and to correlate them with the location of the tumors and with lymph node metastasis. METHODS: One hundred and twenty-five cases of sporadic colon carcinoma (50 in the right colon and 75 in the left colon in patients with no family history of colon carcinoma) were studied. Status of the p53 gene was assessed by polymerase chain reaction (PCR), single strand conformation polymorphism, and sequencing at exons 5-8. Microsatellite instability was analyzed with five microsatellite markers at chromosome 18. The mismatch repair genes hMLH1 and hMSH2 were studied in tumors found to have microsatellite instability by PCR and sequencing. RESULTS: In the 125 cases studied, there were 53 tumors with mutations of the p53 gene. p53 mutations correlated with lymph node metastases from right colon carcinoma cases (61%), and all cases with p53 mutations and microsatellite instability were AJCC/UICC Stage III (Dukes Stage C). In the right colon carcinoma cases the rate of microsatellite instability was related to the tumor size (19% in tumors measuring < 4 cm, and 34% in tumors measuring > 4 cm). No correlation between microsatellite instability and p53 mutations was detected. In the left colon carcinoma cases, p53 mutations were detected in 41% of tumors and microsatellite instability in 14%; neither finding was related to the tumor size. Mutations of the hMLH1 and hMSH2 mismatch repair genes were detected in 7 of 24 cases with marked microsatellite instability. CONCLUSIONS: Microsatellite instability is prone to occur in sporadic right colon carcinoma during tumor growth and is not associated significantly with mutations in the hMLH1 and hMSH2 mismatch repair genes or in the p53 gene. Concomitant detection of microsatellite instability and p53 mutations in right colon carcinoma is associated with the presence of lymph node metastases.

Adaptor Proteins, Signal Transducing↗
PubMed1998

Perspectives in gene therapy.

Gene therapy is understood to be both the restitution of genetic alterations caused by mutation or deletion and the control of overexpressed genes. The concept of gene therapy can also encompass molecular strategies to induce cell death in tumor cell by either the so-called "suicided genes" or by certain viral genes that induce a more selective cell death among the transformed cells. The prospect for the clinical application of gene therapy are enormous and, at least theoretically, its utilization can be extended to a number of diseases known to have a genetic basis, and to neoplastic processes. This review summarizes some of the projects that are currently underway involving neoplastic diseases, liver diseases, hematopoietic cells and respiratory tract cells. The results of most of the ongoing protocols are not yet conclusive, and presumibly, their clinical application is still some years away. One of the major limitations is the method of introducing the genetic sequences into the cells and achieving their constitutive expression by the cells. For ethical reasons, this approach should not be done in germ cells, but at the level of the tissue or cells most closely involved in the development of each gene-based disease. The methods employed in gene therapy are discussed, focusing on those mediated by the application of viral vectors, as well as those requiring the use of liposomes and others.

Animals↗
PubMed1996

Carcinoma cell lines become sensitive to DNA-damaging agents by the expression of the adenovirus E1A gene.

Squamous cell carcinomas can show different oncogenic alterations, histological patterns, and an unpredictable clinical behavior. We previously reported that the adenovirus E1a gene may induce sensitivity to DNA-damaging agents in mouse keratinocytes. In order to study whether E1a expression could be used as a therapeutic agent in different malignant cell lines carrying mutations on the p53 gene and other oncogenic alterations, we transfected and infected several murine and human carcinoma cell lines (HaCa4; MSC11A5; HeLa) with vectors containing the 13S or 12S E1a region. We evaluated the sensitivity to cisplatin (CDDP), doxorubicin (DOX) and gamma irradiation (RX) by the crystal violet method. The induction of apoptosis was assessed by flow cytometry and presence of DNA ladders in agarose gels. The expression of E1a and the tumor suppressor p53 protein was analysed by Western blotting. The carcinoma cell lines expressing E1a were about four- to tenfold more sensitive to CDDP and RX, respectively, than the control cells. Moreover, the reduction in cell viability and cell growth after exposure to CDDP or RX was very significant in the carcinoma cells expressing E1a. With these results, we conclude that expression of E1a may confer great sensitivity to DNA-damaging agents on squamous cell carcinoma cells independently of the p53 protein status and other oncogenic alterations.

Adenoviridae↗
PubMed1995

A genetic model for undifferentiated cell tumor formation: similar tumors formed by different cell lines transformed by the E1A oncogene.

The activation of oncogenes and the mutation/deletion of suppressor genes may be involved in tumor heterogeneity. In an attempt to study tumor heterogeneity, we transformed cell lines from epithelial (PAM 212), mesenchymal (NIH-3T3), or melanocytic origin (L-BIOBR) with the wild type E1a oncogene. To make the cell lines tumorigenic, cells were infected with Harvey sarcoma virus carrying the v-H-ras oncogene. The transformed cells were injected into nude mice and the tumors studied by optical and electron microscopy. The tumors formed by v-H-ras-transformed cells consisted of epitheliod melanomas, spindle cells sarcomas and poorly-differentiated carcinomas, depending on the cell of origin. In contrast, the tumors obtained from cells also carrying the E1a oncogene showed a predominant small and undifferentiated cell pattern regardless of the cell of origin. We conclude that the E1a oncogene products induce a negative control of differentiation, independent of the cell type, and that tumors formed by cells carrying the E1a oncogene display an undifferentiated cell pattern.

Adenovirus E1A Proteins↗
PubMedDate not supplied

Adenovirus lacking the 19-kDa and 55-kDa E1B genes exerts a marked cytotoxic effect in human malignant cells.

UNLABELLED: The adenovirus (Ad) E1A gene exerts an antitumor effect and can induce sensitivity to treatment with DNA-damaging agents. In contrast, the Ad 19-kDa E1B protein inhibits E1A-mediated apoptosis and the 55-kDa E1B inactivates the p53 protein. In this paper, we study the in vitro and in vivo effects of a 19-kDa and 55-kDa E1B-defective Ad in several malignant human tumor cell lines. MATERIALS AND METHODS: Nontumorigenic human fibroblasts (CCD-45SK and Hs67), peripheral blood lymphocytes, and several human tumor cell lines derived from cervix, colon, and breast carcinomas, epidermoid carcinoma, and osteosarcoma (HeLa, HT29, MCF7, Saos-2, and A431 cell lines) were studied. Wild-type (wt) Ad type 5 and H5 dL118 Ad, a mutant with the deleted E1B region, were employed. The cells were infected at 20 plaque-forming units, and cell viability was evaluated by the crystal violet method. In the in vivo experiments, 2 x 10(6) cells from the carcinoma cell lines HeLa, A431 and HT29 were injected into nude mice. The tumorigenicity of previously infected cells and after an intratumoral injection of Ad was analyzed. The mice received whole-body gamma-irradiation. RESULTS: The H5 dL118 mutant produced a marked cytopathic effect in all of the malignant cells, surpassing that of the wt Ad; viability at 72 hours ranged from 11% to 20% for H5 dL118 Ad and from 70% to 93% for the wt Ad with respect to uninfected controls. In the in vivo experiments, a total inhibition of tumorigenicity was detected when cells were infected prior to injection and a partial and transitory decrease in tumorigenicity was detected when the mutant H5 dL118 was injected intratumorally. gamma-irradiation enhanced the in vivo antitumor effects. CONCLUSIONS: These results indicate that infection with completely E1B-deficient Ads induced a marked cytopathic effect on malignant cells that was higher than that seen for wt Ads; in addition, infection with such Ads exerts a tumor suppressor effect in vivo.

Adenoviridae↗
PubMedDate not supplied

In vivo antitumor effect of retrovirus-mediated gene transfer of the adenovirus E1a gene.

The adenovirus E1a gene has been shown to be associated with high sensitivity to DNA-damaging agents and a decrease in the tumorigenicity of some human malignant cell lines. We have analyzed the tumorigenicity of the murine epidermoid carcinoma cell lines MSC11A5 and HaCa4, which have constitutive E1a expression, after the concomitant injection of retrovirus E1a producer cells with the carcinoma cells and even after the intratumoral injection of the E1a producer cells. The level of E1a expression was studied by Western blotting. Tumors induced by carcinoma cell lines expressing E1a showed greater latencies and less tumorigenicity. In the spindle cell carcinomas MSC11A5, E1a gene expression partially blocked tumorigenicity. Similar results were obtained after the concomitant injection of the carcinoma cells and the retrovirus E1a producer cells. Intratumoral injection of retrovirus E1a producer cells was associated with a significant delay of tumorigenicity. By transfection with different E1a mutants Ntd1598, d1922/947, and d1787N, we observed that only the mutant that has complete CR2 domains is associated with the decrease in tumorigenicity. According to these results, we conclude that, at least in these carcinoma cell lines, E1a expression exerts a significant antitumor effect in vivo that is mediated by the CR2 region of E1a gene. We propose that injection of retrovirus E1a producer cells may be a novel therapeutic approach in cancer.

Adenovirus E1A Proteins↗