FISH and chips: chromosomal analysis on microfluidic platforms.

Interphase fluorescence in situ hybridisation (FISH) is a sensitive diagnostic tool used for the detection of alterations in the genome on cell-by-cell basis. However, the cost-per-test and the technical complexity of current FISH protocols have slowed its widespread utilisation in clinical settings. For many cancers, the lack of a cost-effective and informative diagnostic method has compromised the quality of life for patients. We present the first demonstration of a microchip-based FISH protocol, coupled with a novel method to immobilise peripheral blood mononuclear cells inside microfluidic channels. These first on-chip implementations of FISH allow several chromosomal abnormalities associated with multiple myeloma to be detected with a ten-fold higher throughput and 1/10-th the reagent consumption of the traditional slide-based method. Moreover, the chip test is performed within hours whereas the conventional protocol required days. In addition, two on-chip methods to enhance the hybridisation aspects of FISH have been examined: mechanical and electrokinetic pumping. Similar agitation methods have led to significant improvements in hybridisation efficiency with DNA microarray work, but with this cell-based method the benefits were moderate. On-chip FISH technology holds promise for sophisticated and cost-effective screening of cancer patients at every clinic visit.

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.