Raúl Peralta

Human papillomavirus genotypes among females in Mexico: a study from the Mexican institute for social security.

BACKGROUND The aetiological relationship between human papillomavirus (HPV) infection and cervical cancer (CC) is widely accepted. Our goal was to determine the prevalence of HPV types in Mexican women attending at the Mexican Institute for Social Security from different areas of Mexico. MATERIALS AND METHODS DNAs from 2,956 cervical samples were subjected to HPV genotyping: 1,020 samples with normal cytology, 931 with low-grade squamous intraepithelial lesions (LGSIL), 481 with high grade HGSIL and 524 CC. RESULTS Overall HPV prevalence was 67.1%. A total of 40 HPV types were found; HPV16 was detected in 39.4% of the HPV-positive samples followed by HPV18 at 7.5%, HPV31 at 7.1%, HPV59 at 4.9%, and HPV58 at 3.2%. HPV16 presented the highest prevalence both in women with altered or normal cytology and HPV 18 presented a minor prevalence as reported worldwide. The prevalence ratio (PR) was calculated for the HPV types. The analysis of PR showed that HPV16 presents the highest association with CC, HPV 31, -33, -45, -52 and -58 also demonstrating a high association. CONCLUSIONS The most prevalent HPV types in cervical cancer samples were -16, -18, -31, but it is important to note that we obtained a minor prevalence of HPV18 as reported worldwide, and that HPV58 and -52 also were genotypes with an important prevalence in CC samples. Determination of HPV genotypes is very important in order to evaluate the impact of vaccine introduction and future cervical cancer prevention strategies.

Low frequency of human papillomavirus infection in conjunctival squamous cell carcinoma of Mexican patients

BackgroundThe relationship between Human Papillomavirus (HPV) infection and conjunctiva cancer is controversial. HPV detection will provide more information about the role of this infectious agent in the biology of conjunctiva cancer. In the present study, DNA extracted and purified from 36 Conjunctival Squamous Cell Carcinomas (CSCC) was evaluated by PCR for HPV DNA sequences. The results were correlated with the clinical and histopathological variables.ResultsThe results showed that HPV DNA was present in 8 CSCC samples (22%); HPV16 was the sole type detected. Significant association was found between HPV detection and the limbus tumor subtype (p = 0.03). All the samples were non-metastatic squamous cell carcinoma.ConclusionsThe HPV presence in CSCC from Mexican patients is not a common event.

The neurofibromin 1 type I isoform predominance characterises female population affected by sporadic breast cancer: preliminary data

Aims Neurofibromin 1 (NF1) as a tumour suppressor gene can give rise to several transcripts by an alternative splicing event, generated at least for CELF cofactors. At present, the NF1 isoforms and CELF splicing transcripts in sporadic breast cancer are unknown. The aim of the authors was to detect NF1 gene expression, the NF1 isoform ratio and the CELF transcripts present in sporadic breast cancer. Methods Neurofibromin and RAS expression were analysed on tissue microarrays containing sporadic breast cancer (n=22), benign lesions (n=18, including six fibroadenomas, six fibrocystic changes and six ductal hyperplasias) and normal breast tissue (n=6) by immunohistochemistry assay. NF1 and CELF 3–6 RNA expression was performed by end point reverse transcription-PCR in the breast samples. Results NF1 and RAS expression in breast tissues showed no differential expression by immunohistochemistry results. Interestingly, the authors observed a shift transition in the isoform transcripts, from type II in normal breast tissue to type I isoform in breast carcinomas. CELF cofactor expression failed to be related with the shift transition of NF1 in breast tissues. Conclusions These data suggest that there is a tendency for an NF1 expression shift transition from type II to type I isoform, which could comprise a significant event in the development and progression of sporadic breast cancer. This shift transition may not be related with CELF cofactors.

Genetic alterations in a primary medullary thyroid carcinoma and its lymph node metastasis in a patient with 15 years follow-up

BackgroundAssociation between DNA alterations and clinical parameters as recurrence, survival or prognosis has been found in a variety of tumors. A clear association between Medullary Thyroid Carcinoma (MTC) and RET oncogene mutation has been accepted. Specifically M918T RET mutation represents the main genetic event in most cases of sporadic MTC (SMTC) and limited chromosomal alterations analyses have been performed.MethodsIn the present work, a comparative genomic hybridization (CGH) study was performed using DNA from a primary tumor in a M918T RET mutation-positive SMTC patient and from its lymph node metastasis to investigate additional genetic alterations. We studied a patient with 15 years of follow-up and persistence of disease, confirmed by periodical elevated serum calcitonin (CT) levels.ResultsOnly 3 chromosomal imbalances were identified in the primary tumor, gain of 18p, and loss of 6p and 16p region, whereas 25 chromosomal imbalances were identified in the metastasis (9 gains and 16 losses).ConclusionThe chromosomal changes 6p-, 16p-, 18p + could determine in part the oncogenic phenotype in the primary M918T RET positive tumor and probably related to persistence of high serum CT levels in this patient. The additional chromosomal changes observed could be related to the metastasis phenotype. We suggest that some genes mapped at 6p, 16p and 18p chromosomal regions, could act as genes associated to cancer and could be related to persistent SMTC and good prognosis.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1720753793691097

Prevalence of refractive errors in Mexican patients with keratoconus

License. The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. Permissions beyond the scope of the License are administered by Dove Medical Press Limited. Information on how to request permission may be found at: http://www.dovepress.com/permissions.php Clinical Optometry 2015:7 39–44 Clinical Optometry Dovepress

HPV Could be a Potential Factor of Survival in Laryngeal Cancer: a Preliminary Study in Mexican Patients

Introduction: In Head and Neck (HN) cancer, the High-Risk Human Papillomavirus (hr HPV) infection has been associated in about 40% of these tumors. The hr HPV infection is one of the etiological factors of several epithelial tumors; however, its association with the prognosis has not yet been established for patients with Laryngeal Squamous Cell Carcinoma (LSCC). On the other hand, Epidermal Growth Factor Receptor (EGFR) is a molecular marker widely studied in cancer and its overexpression has been associated with poor prognosis in some types of cancer, including the HN cancer. In the present study, we analyzed EGFR expression and HPV detection in a cohort of Mexican patients with LSCC and define their association with clinical-pathological and survival parameters. Methods: EGFR expression analysis was performed by immunohistochemistry assay. A tissue array was constructed based on 30 paraffin-embedded tissue samples. HPV detection was performed by PCR. The results were then compared with the clinical-pathological variables and outcome measures (Kaplan Meier and Cox analysis). Results: High expression of EGFR was observed in 43% of the samples and 20% of HPV detection. The statistical analyses provided evidence of disassociation between clinical-pathological parameters and EGFR expression, but there was an association with poor prognosis. Interestingly, HPV detection is slightly associated with good prognosis. Conclusion: Both, EGFR overexpression and HPV presence could be associated with an unfavorable prognosis in patients with LSCC, independently of other clinical-pathological factors.

Functional Analysis of the Cervical Carcinoma Transcriptome: Networks and New Genes Associated to Cancer

Cancer is one of the most important public health problem in Mexico and worldwide, especially for female population, breast and cervical cancer (CC) types are the most frequent. Incidence rates of CC are higher in developing countries 40/100,000 women per year vs. 10/100,000 in developed countries (1). In Mexico there are 12,000 new reports cases every year (2). The absence of the screening programs or comparatively ineffective screening programs lead to relatively late diagnosis of the disease and also in differences in the human papillomavirus (HPV) infection (3). Several types of HPV are associated with CC worldwide (4, 5), being the HPV16 the most frequent oncogenic type. Epidemiological and experimental studies suggest that high risk HPV have an important role in cervical carcinogenesis. Persistent viral infection, genetic background in combination with constitutive expression of the viral oncogenes as E6 and E7, are decisive steps for malignant transformation, because these oncoproteins interact with the tumour suppressor proteins p53 and pRB, respectively for their degradation (6, 7). Finally, these interactions could induce cellular proliferation and genetic instability for example, which could promote the accumulation of mutations and aneuploidy (8). In conclusion, viral oncoproteins have a general impact in global profile of expressed genes, which could be analyzed by highthroughput methodologies. One of these techniques is DNA oligonucleotide-based microarray technology, which allows a rapid and high-throughput detection of thousands of transcripts simultaneously (9-11). It has been published several studies about gene expression profiles in HPV infected cells. Mainly these reports are based on gene expression levels altered by E6 and E7 HPV oncoproteins (12-17). Regarding changes in gene expression profiles in cervical cancer