A subgroup of HOX Abd-B gene is differentially expressed in cervical cancer

The HOX genes are a family of transcription factors that bind to specific sequences of DNA in target genes regulating their expression. The role of HOX genes in adult cell differentiation is still obscure, but growing evidence suggests that they may play an important role in the development of cancer. In order to study the role of the HOX Abd-B genes in cervical cancer, we analyzed their expression in cervical tissues. Reverse transcription-polymerase chain reaction and RNA in situ hybridization were used to detect HOX Abd-B messenger RNA expression in nine normal cervical tissues and ten cervical carcinomas. The normal tissues were human papillomavirus (HPV) negative, whereas all invasive carcinomas included were HPV16 positive. In this study, we show that HOXA9, A10, A11, A13, B9, D11, and D13 genes are expressed in both the epithelium of normal tissues and neoplastic cells from squamous cervical carcinomas. Interestingly, the HOXC10 and D12 genes were not expressed in any cervical tissues; however, HOXB13, C9, C11, C12, C13, D9, and D10 genes were expressed only in the tumoral tissues but not in the normal cervix. Our findings suggest that the expression of HOXB13, D9, D10, and HOXC cluster (HOXC9, C11-C13) genes might be an important step involved in cervical cancer.

HOXB homeobox gene expression in cervical carcinoma

The homeobox (HOX) genes are a family of transcription factors that bind to specific DNA sequences in target genes regulating gene expression. Thirty-nine HOX genes have been mapped in four conserved clusters: A, B, C, and D; they act as master genes regulating the identity of body segments along the anteroposterior axis of the embryo. The role played by HOX genes in adult cell differentiation is unclear to date, but growing evidence suggests that they may play an important role in the development of cancer. To study the role played by HOX genes in cervical cancer, in the present work, we analyzed the expression of HOXB genes and the localization of their transcripts in human cervical tissues. Reverse transcription-polymerase chain reaction analysis and nonradioactive RNA in situ hybridization were used to detect HOXB expression in 11 normal cervical tissues and 17 cervical carcinomas. It was determined that HOXB1, B3, B5, B6, B7, B8, and B9 genes are expressed in normal adult cervical epithelium and squamous cervical carcinomas. Interestingly, HOXB2, HOXB4, and HOXB13 gene expression was found only in tumor tissues. Our findings suggest that the new expression of HOXB2, HOXB4, and B13 genes is involved in cervical cancer.

A simple method for the construction of small format tissue arrays

Tissue arrays can evaluate molecular targets in high numbers of samples in parallel. Array construction presents technical difficulties and tissue arrayers are expensive, particularly for small and medium sized laboratories. This report describes a method for the construction of 36 sample arrays using widely available materials. A blunted 16 gauge needle for bone marrow aspiration was used to extract paraffin wax cylinders and manually define a 6 x 6 matrix on a blank paraffin wax block. Tissue cores from 36 paraffin wax embedded premalignant lesions and invasive cervical carcinomas were injected into the matrix using a 14 gauge needle. This tissue array was sectioned using a standard microtome and used for the immunodetection of CD44 variant 9 and interleukin 18 with satisfactory results. This method can be applied in any laboratory, without the need of specialised equipment, offering a good alternative for the wider application of tissue arrays.

Nitrogen budget in Scenedesmus obliquus cultures with artificial wastewater

Semicontinuous cultures of Scenedesmus obliquus in artificial wastewater, recycled into proteins about 33% and 25% of the dissolved nitrogen missing from the medium 24 h after harvesting 50% and 70% of the culture, and replacing the volume harvested with fresh medium. The residual dissolved nitrogen concentrations were 25% and 43% of the initial, respectively, with an imbalance in the mass budget close to 17 and 20 mg N l(-1) d-1. Most or all the nitrogen missing was found in an ammonia trap located at the air vent of the closed cultures, showing that an important role of microalgae in wastewater treatment is that of favouring NH3 stripping due to the photosynthesis-induced pH increases.