Production of levan from Bacillus subtilis var. natto and apoptotic effect on SH-SY5Y neuroblastoma cells.

Levan is a high-valued polysaccharide of fructose produced by several microbial species. These polysaccharides have been described as effective therapeutic agents in some human disease conditions, such as cancer, heart diseases and diabetes. The objective of this study was to examine the effect of levan (ß-(2 â†’ 6)-fructan) produced through sucrose fermentation by B. subtilis var. natto on the proliferation rate, cytotoxicity, and apoptosis of human neuroblastoma SH-SY5Y cells. It was obtained 41.44 g/L of levan in 18 h by biotechnological fermentation and SH-SY5Y cells were exposed to 1000 µg/mL of levan. The treatment with 1000 µg/mL of levan induced apoptosis in SH-SY5Y cancer cells by the significant increase in Annexin V/7-AAD and caspase 3/7 activation, but did not decrease proliferation or triggered a cytotoxic effect. 1000 µg/mL levan treatment is a promising therapeutic strategy for SH-SY5Y neuroblastoma cells.

Eag1 potassium channels as markers of cervical dysplasia.

Human ether à-go-go 1 (Eag1) potassium channels are potential tumor markers and therapeutic targets for several types of malignancies, including cervical cancer. Estrogens and human papilloma virus oncogenes regulate Eag1 gene expression, suggesting that Eag1 may already be present in pre-malignant lesions. Therefore, Eag1 could be used as an early marker and/or a potential risk indicator for cervical cancer. Consequently, we studied Eag1 protein expression by immunochemistry in cervical cancer cell lines, normal keratinocytes, cervical cytologies from intraepithelial lesions, biopsies from cervical intraepithelial neoplasias (CIN 1, 2 and 3) and in normal smears from patients taking or not taking estrogens. Two hundred and eighty-six samples obtained by liquid-based cytology and fifteen CIN biopsies were studied. We observed Eag1 protein expression in the cervical cancer cell lines, as opposed to normal keratinocytes. Eag1 was found in 67% of the cervical cytologies from low-grade intra-epithelial lesions and in 92% of the samples from high-grade intraepithelial lesions, but only in 27% of the normal samples. Noteworthy, morphologically normal cells obtained from dysplastic samples also exhibited Eag1 expression. In CIN biopsies we found that the higher the grade of the lesion, the broader the Eag1 protein distribution. Almost 50% of the normal patients taking estrogens displayed Eag1 expression. We suggest Eag1 as a potential marker of cervical dysplasia and a risk indicator for developing cervical lesions in patients taking estrogens. Eag1 detection in cervical cancer screening programs should help to improve early diagnosis and decrease mortality rates from this disease.

Ether à go-go potassium channel expression in soft tissue sarcoma patients.

BACKGROUND: The expression of the human Eag1 potassium channel (Kv10.1) is normally restricted to the adult brain, but it has been detected in both tumour cell lines and primary tumours. Our purpose was to determine the frequency of expression of Eag1 in soft tissue sarcoma and its potential clinical implications. RESULTS: We used specific monoclonal antibodies to determine the expression levels of Eag1 in soft tissue sarcomas from 210 patients by immunohistochemistry. Eag1 was expressed in 71% of all tumours, with frequencies ranging from 56% (liposarcoma) to 82% (rhabdomyosarcoma). We detected differences in expression levels depending on the histological type, but no association was seen between expression of this protein and sex, age, grade or tumour size. Four cell lines derived from relevant sarcoma histological types (fibrosarcoma and rhabdomyosarcoma) were tested for Eag1 expression by real-time RT-PCR. We found all four lines to be positive for Eag1. In these cell lines, blockage of Eag1 by RNA interference led to a decrease in proliferation. CONCLUSION: Eag1 is aberrantly expressed in over 70% sarcomas. In sarcoma cell lines, inhibition of Eag1 expression and/or function leads to reduced proliferation. The high frequency of expression of Eag1 in primary tumours and the restriction of normal expression of the channel to the brain, suggests the application of this protein for diagnostic or therapeutic purposes.