ANTITUMOR PROPERTIES OF VEGETABLE OIL EXTRACT FROM GREEN MICROALGA COELASTRELLA SP

Microalgae are of great importance for the production of original natural substances of interest for food, health or biotechnological applications. Mass cultures of green microalgae are used for production of carotenoids such β-carotene, astaxanthin, canthaxanthin, lutein etc. The aim of this study was to obtain an oil extract from a Bulgarian green microalga strain Coelastrella sp. BGV and to assess its anticancer and apoptogenic activity in vitro against human tumor cells HeLa by means of MTT and fluorescence microscopy analyses. The results showed that the oil extract obtained by a direct extraction using a common vegetable oil reduces proliferation and induces apoptosis in HeLa cells. In contrast to widely used organic solvents for the production of carotenoids, the applied bio-solvent (sunflower oil) can be a valuable alternative approach for the needs of the food industry. The resulting oil extract showed promising antitumor and apoptosis-inducing activity against HeLa cells in vitro and potential for future use in practice.

High diversity of thermophilic cyanobacteria in Rupite hot spring identified by microscopy, cultivation, single-cell PCR and amplicon sequencing

Genotypic and morphological diversity of cyanobacteria in the Rupite hot spring (Bulgaria) was investigated by means of optical microscopy, cultivation, single-cell PCR, and 16S rRNA gene amplicon sequencing. Altogether, 34 sites were investigated along the 71-39 °C temperature gradient. Analysis of samples from eight representative sites shown that Illumina, optical microscopy, and Roche 454 identified 72, 45 and 19% respective occurrences of all cumulatively present taxa. Optical microscopy failed to detect species of minor occurrence; whereas, amplicon sequencing technologies suffered from failed primer annealing and the presence of species with extensive extracellular polysaccharides production. Amplicon sequencing of the 16S rRNA gene V5-V6 region performed by Illumina identified the cyanobacteria most reliably to the generic level. Nevertheless, only the combined use of optical microscopy, cultivation and sequencing methods allowed for reliable estimate of the cyanobacterial diversity. Here, we show that Rupite hot-spring system hosts one of the richest cyanobacterial flora reported from a single site above 50 °C. Chlorogloeopsis sp. was the most abundant at the highest temperature (68 °C), followed by Leptolyngbya boryana, Thermoleptolyngbya albertanoae, Synechococcus bigranulatus, Oculatella sp., and Desertifilum sp. thriving above 60 °C, while Leptolyngbya geysericola, Geitlerinema splendidum, and Cyanobacterium aponinum were found above 50 °C.

Smoking, alcohol, diet, dentition and sexual practices in the epidemiology of oral cancer in Poland

The effect of smoking, drinking, diet, dental care and sexual habits on the risk of oral and pharyngeal cancer was investigated in a case-control study conducted in Warsaw, Poland. The study comprised 122 patients (including 44 females) aged 23-80 years with histologically confirmed cancer of oral cavity and pharynx. Controls were 124 subjects (including 52 females) admitted to the hospital for different non-neoplastic conditions unrelated to tobacco and alcohol consumption, with frequency matched to cases by age and sex. Smoking and drinking were strongly associated with an increased risk of oral cancer. Among consumers of both products, risks of oral cancer tended to combine in a multiplicative fashion and were increased more than 14-fold among those who consumed more than 15 cigarettes and seven or more drinks per day. Cessation of smoking was associated with reduced risk of this cancer. The risks varied by type of cigarettes smoked, being lower among those consuming filtered cigarettes only (OR = 1.6) than nonfilter (OR = 6.5) or mixed (OR = 4.2) cigarettes. High fruit intake was associated with significantly decreased risk (OR = 0.4) with the strongest significant inverse association found for fruit juices and citrus fruits ( < 0.01). After adjustment for tobacco smoking and alcohol drinking, poor dentition as evidenced by missing teeth, frequency of dental check-ups and frequency of teeth brushing emerged as a strong risk factor. Number of missing teeth and frequency of dental check-ups and frequency of tooth brushing showed increased ORs of 9.8, 11.9 and 3.2, respectively. Denture wearing did not affect oral cancer risk. No differences were detected in sexual practices (including oral sex and intercourse with prostitutes). In terms of attributable risk, smoking accounted for 57% of oral cancer cases in Poland, alcohol for 31% and low fruit intake for 12%. Attributable risks for low frequency of tooth brushing and dental check-ups were 56% and 47%, respectively. In conclusion, smoking and drinking cessation and increase of fresh fruit intake are likely to be effective preventive measures against oral cancer. These findings indicate also that poor oral hygiene may be an independent risk factor.

No evidence for c-erbB-2 overexpression in cutaneous melanoma

BACKGROUND

Recent studies have demonstrated the expression of the c-erbB-2 (HER-2/neu) oncoprotein in several malignant tumors and have related its overexpression with poor prognosis. Because cutaneous melanoma is a malignant tumor associated with poor prognosis, we investigated the expression of c-erbB-2 protein in cutaneous melanoma and in melanoma metastatic to the skin.

MATERIALS AND METHODS

The expression of c-erbB-2 protein in 20 primary cutaneous melanomas and in 10 melanomas metastatic to the skin was investigated using a semi-quantitative immunohistochemical assay.

RESULTS

No specific staining with c-erbB-2 antibody was observed in any of the 20 cases of primary malignant melanoma or 10 cases of melanoma metastatic to the skin.

CONCLUSION

c-erbB-2 overexpression does not appear to play a role in the development of primary cutaneous melanoma or in the development of metastatic melanoma, indicating that mechanisms other than c-erbB-2 overexpression are involved in the pathogenesis of cutaneous melanoma.