In DNA binding studies using a consensus octamer recognition site we have found that 4 of 8 MCC cell lines examined expressed brn-2 in at least trace amounts compared with 3 SCLC cell lines which all expressed brn-2 proteins at high levels.
We describe a case of a 73-year-old man who had cutaneous large cell lymphoma in the right leg (immunophenotype CD45+, CD19+, CD20+ CD22+, lambda clonal, cytokeratin-, NSE-) and lymphoma in left leg simulating Merkel cell carcinoma showing absence of leukocyte antigens (CD45-, CD20-, no light chains) and focal expression of keratin and NSE.
We describe a case of a 73-year-old man who had cutaneous large cell lymphoma in the right leg (immunophenotype CD45+, CD19+, CD20+ CD22+, lambda clonal, cytokeratin-, NSE-) and lymphoma in left leg simulating Merkel cell carcinoma showing absence of leukocyte antigens (CD45-, CD20-, no light chains) and focal expression of keratin and NSE.
TP53 mis-sense mutations and one non-sense mutation were detected in three of 15 examined MCCs, suggesting that TP53 mutations may play a role in the pathogenesis or progression of a subset of MCCs.
These results suggest that neither transcript of the CDKN2A locus is the target of deletions on 9p in MCC and imply the existence of tumour-suppressor genes mapping both centromeric and telomeric of this locus.
To study the possible role of PTEN in MCC oncogenesis, loss of heterozygosity (LOH) analysis for the 10q23 region was performed on 26 MCC tumor samples from 23 MCC patients.
We propose that HATH1 and Brn-3c may form a transcriptional hierarchy responsible for determining neuroendocrine phenotype in Merkel cells and that lack of Brn-3c and/or HATH1 in MCC may indicate a more aggressive disease requiring closer patient follow-up.
We propose that HATH1 and Brn-3c may form a transcriptional hierarchy responsible for determining neuroendocrine phenotype in Merkel cells and that lack of Brn-3c and/or HATH1 in MCC may indicate a more aggressive disease requiring closer patient follow-up.
In SCLC, the related basic helix-loop-helix transcription factor HASH1 is responsible for neuroendocrine phenotype, but HASH1 transcripts were not detected in MCC cell lines.
We propose that HATH1 and Brn-3c may form a transcriptional hierarchy responsible for determining neuroendocrine phenotype in Merkel cells and that lack of Brn-3c and/or HATH1 in MCC may indicate a more aggressive disease requiring closer patient follow-up.
We propose that HATH1 and Brn-3c may form a transcriptional hierarchy responsible for determining neuroendocrine phenotype in Merkel cells and that lack of Brn-3c and/or HATH1 in MCC may indicate a more aggressive disease requiring closer patient follow-up.