Gender differences in UVB-induced skin carcinogenesis, inflammation, and DNA damage.

The American Cancer Society reports the incidence of squamous cell carcinoma in males to be thrice the incidence in females. This increased squamous cell carcinoma incidence has been attributed to men accumulating more sun exposure and using less sun protection than women. To date, there have been no controlled studies examining the effect of gender on skin tumor development following equal doses of UVB. Gender differences in UVB-induced skin carcinogenesis were examined using the Skh-1 mouse model. After chronic exposure to equal doses of UVB, male mice developed tumors earlier and had more tumors than female mice; tumors in male mice tended to be larger, and the total tumor burden was greater than in females. In addition, tumors in males were of more advanced histologic grade compared with those of female mice. To evaluate the contribution of differences in inflammation and DNA damage to differences in skin carcinogenesis, male and female Skh-1 mice were exposed once to 2,240 J/m(2) UVB and examined 48 h after exposure. Surprisingly, male mice developed less of an inflammatory response, as determined by skin fold thickness and myeloperoxidase activity, compared with females. Interestingly, male mice showed more cutaneous oxidative DNA damage than the females and lower antioxidant levels. These results show a gender bias in skin carcinogenesis and suggest that the gender difference in tumor development is more influenced by the extent of oxidative DNA damage and antioxidant capacities than by inflammatory response.

Fine-needle aspiration biopsy of non-Hodgkin lymphoma for use in expression microarray analysis.

BACKGROUND: The majority of patients with lymphoma undergo a single biopsy for diagnosis, and there are few opportunities to acquire posttreatment material. Fine-needle aspiration (FNA) biopsy is a minimally invasive procedure, and acquiring routine posttreatment material would require minimal effort and provide needed material for gene expression profiling. METHODS: Ex vivo FNA biopsies were performed using a standard clinical technique with 21-gauge, 22-gauge, 23-gauge, and 25-gauge needles for 8 lymph node specimens and were collected in either RNA stabilization reagent (RNAlater) or Trizol. Eight patients with known or suspected Non-Hodgkin lymphoma (NHL) underwent interoperative (in vivo) FNA biopsies based on the best technique derived from the ex vivo aspirates. RNA derived from the in vivo FNA biopsies and the matched, snap-frozen surgical lymph node biopsy remnant was used for gene expression analysis with proprietary U133A chips. RESULTS: The results confirmed the authors' experience, that RNA isolated from FNA biopsies of lymph nodes collected in Trizol is superior both quantitatively and qualitatively to RNA collected in RNAlater. Gene expression profiles of NHL derived from in vivo FNA biopsies and matched, frozen surgical specimens showed good overall correlation. CONCLUSIONS: High-throughput gene expression analysis in patients with NHL derived from material acquired by FNA biopsy is a feasible approach to developing a platform for real-time analysis of treatment responses in this group of patients.

MYC amplification and polysomy 8 in chondrosarcoma: array comparative genomic hybridization, fluorescent in situ hybridization, and association with outcome.

PURPOSE: To identify recurrent regions of genomic gain or loss in chondrosarcoma in a clinically relevant and statistically valid fashion. MATERIALS AND METHODS: Array comparative genomic hybridization (CGH) results of 15 frozen tumor samples of high-grade chondrosarcoma for chromosome 8 are presented. A separate subset of 116 cartilaginous tumors with outcome data was used for validation. RESULTS: Array CGH identified gain at 8q24.12-q24.13, the region of the MYC (c-Myc) oncogene, as a frequent change in high-grade chondrosarcoma. In the validation arm of 116 cartilaginous tumors, MYC was frequently amplified in G2 (15%), G3 (20%), and dedifferentiated (21%) chondrosarcomas. No amplification was identified in samples of enchondroma and grade 1 chondrosarcoma. In samples without MYC amplification, polysomy 8 was a frequent finding in grade 1 (18%), grade 2 (31%), grade 3 (80%), and dedifferentiated (29%) chondrosarcomas, but was not found in any samples of enchondroma. MYC protein expression was identified in all samples with amplification, but was also frequent in the remaining samples without amplification or polysomy 8. Kaplan-Meier survival curves for overall survival showed a statistically significant difference for patients with MYC amplification or polysomy 8 (P = .034). Univariate analysis involving Cox proportional hazards models showed that grade (P = .003), polysomy 8 (P = .045), and MYC amplification (P = .053) correlated with shorter overall survival. By multivariate analysis, grade of chondrosarcoma (P = .026) was the only factor to reach statistical significance. CONCLUSION: MYC amplification and polysomy 8 can be used as markers of prognostic importance in chondrosarcoma. Molecular targeting of MYC expression may have therapeutic potential in the future for subsets of chondrosarcoma.