Endothelin-3 growth factor levels decreased in cervical cancer compared with normal cervical epithelial cells.

We used cDNA microarray analysis of RNA extracted from normal, dysplastic, and cancerous cervical tissues to identify the changes in gene expression during the procession from normal to cancerous cervical epithelial cells. We found the expression of 5 genes in cancerous cervical epithelial cells that were not found in normal cervical epithelial cells, among which were lymphoid-restricted membrane protein, protease serine 2, WD repeat domain 59, thyrotropin-releasing hormone degrading enzyme, and the endothelin-3 growth factor. We then analyzed the expression levels of endothelin growth factors 1, 2, and 3 (ET-1, ET-2, and ET-3) and their receptors A and B (ETR-A and ETR-B) by reverse transcriptase-polymerase chain reaction in 3 cervical cancer cell lines and by immunohistochemical staining in cervical normal, dysplastic, and cancer tissues. ET-1, ET-2, and ET-3 growth factor levels were detectable in the maturing layer of cervical epithelium but not in the germinal layer. All 3 growth factors (ET-1, ET-2, and ET-3) were detected in the cytoplasm of the maturing normal cervical epithelial cells. In addition, there were decreased levels of ET-3 and increased levels of ET-1, ET-2, ETR-A, and ETR-B in cancerous cervical epithelial cells compared with normal cervical epithelial cells. These results suggest that the reduction of ET-3 growth factor levels may be important in the transition from normal to cancerous cervical epithelium.

Three pathogen-inducible genes encoding lipid transfer protein from pepper are differentially activated by pathogens, abiotic, and environmental stresses.

The three cDNA clones, CALTPI, CALTPII, and CALTPIII, corresponding to pepper lipid transfer protein (LTP) genes were isolated from a pepper (Capsicum annuum) cDNA library from hypersensitive response (HR) lesions of leaves infected with Xanthomonas campestris pv. vesicatoria. The CALTP genes are well conserved in their coding region with 57-72% identity at the amino acid level, but display 72-83% identity at the nucleotide sequence level. The transcripts of the three CALTP genes differentially accumulated in pepper leaf, stem, and fruit tissues infected by X. campestris pv. vesicatoria, Phytophthora capsici and Colletotrichum gloeosporioides. The CALTP genes were also strongly induced in the systemic, upper leaves after immunization on lower leaves by either pathogenic or non-pathogenic bacteria. In situ hybridization results showed that the CALTPI mRNA was localized in phloem cells of vascular tissues in pepper leaf, stem and fruit tissues after pathogen infection. CALTPI and CALTPIII genes were predominantly expressed in various pepper tissues infected by pathogens, while infection by P. capsici and C. gloeosporioides did not induce the transcription of the CALTPII gene. Ethylene, methyl jasmonate and abscisic acid induced CALTPI and III gene expression in pepper leaves. Drought, high salinity, low temperature and wounding stresses also induced the expression of the CALTPI and CALTPIII genes in a similar manner. In contrast, only high salinity induced the CALTPII expression that was not generally affected by abiotic and other environmental stimuli. When compared with each other and with LTPs from other plants, CALTPI is more distantly related than CALTPII and CALTPIII sequences, indicating that the three pepper CALTP genes represent two different classes. These results thus show that CALTPI and CALTPIII genes, although different in sequence structure, are transcriptionally activated in pepper tissues by pathogen infection as well as abiotic and environmental stresses.