[Genes associated to cancer]. / Los genes del cáncer.

In 2010, in a cancer genes census, 291 genes were enumerated. These represent near to the 1 % of the total genes, for which there is enough biological evidence that they belong to a new genes classification, known as the cancer genes. These have been defined as the causal genes for sporadic or familiar cancer, when they mutate. The mutation types for these genes includes amplifications, point mutations, deletions, genomic rearranges, amongst others, which lead to a protein over-expression, muting, production of chimeric proteins or a de novo expression. In conjunction these genomic alterations or those of the genetic expression, when they affect specific genes which contribute to the development of cancer, are denominated as cancer genes. It is possible that the list of these alterations will grow longer due to new strategies being developed, for example, the genomic analysis.

En el año 2010, en un censo de genes del cáncer, se enumeraron 291 genes humanos que representan cerca del 1 % de los genes totales, para los cuales existe suficiente evidencia biológica de que pertenecen a una nueva clasificación de genes: los genes del cáncer. Estos se han definido como los genes causales de cáncer esporádico o cáncer familiar, cuando mutan. El tipo de mutaciones para estos genes del cáncer incluye las amplificaciones, las mutaciones puntuales, las deleciones, los rearreglos genómicos, entre otros, los cuales conducen a una sobreexpresión proteica, silenciamiento, producción de proteínas quiméricas o una expresión de novo. Cuando afectan genes específicos que contribuyen al desarrollo de un cáncer, estas alteraciones genómicas o de la expresión génica son denominadas en conjunto como genes del cáncer. Es posible que esta lista crezca más debido a las nuevas estrategias que se están desarrollando, como, por ejemplo, las de análisis genómico.

Heterogeneity of microRNAs expression in cervical cancer cells: over-expression of miR-196a.

In recent years, the study of microRNAs associated with neoplastic processes has increased. Patterns of microRNA expression in different cell lines and different kinds of tumors have been identified; however, little is known about the alterations in regulatory pathways and genes involved in aberrant set of microRNAs. The identification of these altered microRNAs in several cervical cancer cells and potentially deregulated pathways involved constitute the principal goals of the present study. In the present work, the expression profiles of cellular microRNAs in Cervical Cancer tissues and cell lines were explored using microRNA microarray, Affymetrix. The most over-expressed was miR-196a, which was evaluated by real time PCR, and HOXC8 protein as potential target by immunohistochemistry assay. One hundred and twenty three human microRNAs differentially expressed in the cell tumor, 64 (52%) over-expressed and 59 (48%) under-expressed were observed. Among the microRNAs over-expressed, we focused on miR-196a; at present this microRNA is poorly studied in CC. The expression of this microRNA was evaluated by qRT-PCR, and HOXC8 by immunohistochemistry assay. There is not a specific microRNA expression profile in the CC cells, neither a microRNA related to HPV presence. Furthermore, the miR-196a was over-expressed, while an absence of HOXC8 expression was observed. We suggest that miR-196a could be played as oncomiR in CC.

Prevalence of human papillomavirus in the cervical epithelium of Mexican women: meta-analysis.

BACKGROUND: Human Papillomavirus (HPV) in cervical epithelium has been identified as the main etiological factor in the developing of Cervical Cancer (CC), which has recently become a public health problem in Mexico. This finding has allowed for the development of vaccines that help prevent this infection. In the present study, we aimed to determine the prevalence and HPV type-distribution in Mexican women with CC, high-grade squamous intraepithelial lesion (HSIL), low-grade squamous intraepithelial lesion (LSIL), and Normal cytology (N) to estimate the impact of the HPV vaccines. METHODS: The PubMed database was used to identify and review all articles that reported data on HPV prevalence in CC, precursor lesions, and normal cytology of Mexican women. RESULTS: A total of 8,706 samples of the tissues of Mexican women were stratified according to diagnosis as follows: 499 for CC; 364 for HSIL; 1,425 for LSIL, and 6,418 for N. According to the results, the most prevalent genotypes are the following: HPV16 (63.1%), -18 (8.6%), -58, and -31 (5%) for CC; HPV-16 (28.3%), 58 (12.6%), 18 (7.4%), and 33 (6.5%) for HSIL; HPV-16 (13.1%), 33 (7.4%), 18 (4.2%), and 58 (2.6%) for LSIL, and HPV-16 (3.4%), 33 (2.1%), 18, and 58 (1.2%) for N. CONCLUSIONS: Taken together, genotypes 58 and 31 (10%) are more common than type 18 (8.6%) in CC. Therefore, the inclusion of these two genotypes in a second-generation vaccine would provide optimal prevention of CC in Mexico.

[The nanotechnology as a support for diagnosis and prognosis in cancer research]. / La nanotecnología en apoyo a la investigación del cáncer.

Recently, technological advances have greatly increased, generating the development of nanotechnology, which is responsible for the design of structures and materials in the nanometer scale. This creates one of the most important cutting-edge sciences, integrating physics, chemistry, engineering and biology sciences. Specifically the integration with biology results in a new science called nanobiotechnology, specifically nanomedicine, which has the goal of mainly looking for more precise molecular diagnostic and prognostic processes, as well as the new design of drugs in the personalized medicine field. On the other hand, at molecular level in medical research, the nanoparticles are most commonly used as tools. Molecular diagnostics uses gold nanoparticles, paramagnetic nanoparticles and quantum dots, which can be used for the diagnosis and treatment of several diseases, including cancer. Quantum dots are the most promising tools for diagnosis and therapy in cancer research.

Gene identification by cDNA arrays in HPV-positive cervical cancer.

BACKGROUND: One of the most frequent malignancies in women worldwide is carcinoma of the uterine cervix. High-risk human papillomavirus (HPV) infection is considered the most important etiological factor of uterine cervical cancer. Our aim was to identify novel cellular genes that could potentially act as predictive molecular markers for human cervical cancer by means of cDNA arrays. METHODS: We used cDNA arrays to examine the expression profiles of six cell lines derived from human cervical cancer, three HPV+ tumor samples and three normal (HPV-) epithelium tissues. Data normalization was performed and the top overexpressed genes were obtained. Hierarchical cluster was performed and, to validate some of the differentially expressed genes between normal and carcinogenic samples, semi-quantitative RT-PCR, in situ hybridization and immunohistochemistry were performed in tissue samples. RESULTS: Four genes were demonstrated to be consistently overexpressed in invasive cervical cancer biopsies; three novel genes not previously related to cervical cancer: MMP10, Lamc2 and Claudin 1. Moreover, overexpression of IL6 and VEGF was corroborated. CONCLUSIONS: The identification of characteristic molecular changes in cervical cells by carcinogenesis and HPV infection can lead to a better understanding of cervical cancer. cDNA arrays are beginning to provide new possible molecular markers for prognosis and diagnosis. This technology could eventually help to elucidate the biological differences of the particular mechanisms associated with each different HPV-type infection and those with a poor prognosis.