Faculty Bibliography

Cutaneous squamous cell carcinoma (SCC) is the second most common human cancer and can behave aggressively. Mohs micrographic surgery offers the highest cure rates for high-risk SCCs and is particularly useful for SCCs on challenging anatomic sites

Tumor-associated macrophages (TAMs) may have an important role in tumor immunity. We studied the activation state of TAMs in cutaneous SCC, the second most common human cancer. CD163 was identified as a more abundant, sensitive, and accurate marker of TAMs when compared with CD68. CD163(+) TAMs produced protumoral factors, matrix metalloproteinases 9 and 11 (MMP9 and MMP11), at the gene and protein levels. Gene set enrichment analysis (GSEA) was used to evaluate M1 and M2 macrophage gene sets in the SCC genes and to identify candidate genes in order to phenotypically characterize TAMs. There was coexpression of CD163 and alternatively activated 'M2' markers, CD209 and CCL18 (chemokine (C-C motif) ligand 18). There was enrichment for classically activated 'M1' genes in SCC, which was confirmed in situ by colocalization of CD163 and phosphorylated STAT1 (signal transducer and activator of transcription 1), IL-23p19, IL-12/IL-23p40, and CD127. Also, a subset of TAMs in SCC was bi-activated as CD163(+) cells expressed markers for both M1 and M2, shown by triple-label immunofluorescence. These data support heterogeneous activation states of TAMs in SCC, and suggest that a dynamic model of macrophage activation would be more useful to characterize TAMs

Metastases from primary cutaneous squamous cell carcinoma (SCC) account for the majority of the approximately 10,000 non-melanoma skin cancer deaths in the United States annually. We studied lymphangiogenesis in human SCC because of the potential link to metastasis. SCC samples were stained for lymphatic endothelial vessel marker LYVE-1 and positive cells were counted and compared with cells in normal skin. Gene set enrichment analysis and reverse transcription (RT)-PCR were performed on SCC, on adjacent non-tumor-bearing skin, and on normal skin to determine the differential expression of lymphangiogenesis-associated genes. Laser capture microdissection (LCM) was performed to isolate tumor cells and tumor-associated inflammatory cells for further gene expression analysis. Immunofluorescence was performed to determine the source of vascular endothelial growth factor-C (VEGF-C) in the tumor microenvironment. We found increased lymphatic density and reorganized lymphatic endothelial vessels in the dermis immediately adjacent to SCC nests. RT-PCR confirmed the presence of VEGF-C in skin immediately adjacent to SCC. LCM confirmed the increased expression of VEGF-C, the SCC inflammatory infiltrate. The presence of CD163(+)/CD68(+)/VEGFC(+) cells and absence of VEGF-C expression by CD3(+) or CD11C(+) cells suggested that VEGF-C is derived from tumor-associated macrophages. Clarification of mechanisms governing SCC-mediated lymphangiogenesis may identify potential targets for therapeutic intervention against aggressive or inoperable disease

Squamous cell carcinoma (SCC) is the most frequent cancer in organ transplant recipients (OTRs). The immune system plays a major role in the fight against SCC, however, little is known about the local inflammatory response in SCC at all. We analyzed quantity and quality of the perineoplastic inflammatory SCC microenvironment in immunocompetent patients and immmunosuppressed OTRs. RNA expression profile of SCC patients was analyzed for 8 different sets of genes relating to Th1 versus Th2 response using Gene Set Enrichment Analysis. SCC from immunocompetent patients and OTRs were analyzed by real-time polymerase chain reactions for CD4, CD8, TBET, GATA-3, FOXP3, RORC, IFN-gamma, IL-4, TGF-beta, IL-10, and IL-17A mRNA expression. Immunohistochemistry was carried out in SCC for CD3, CD4, CD8, and FOXP3 expression. Considerable inflammation was seen in both patient groups. SCC in immunocompetent patients and OTRs was associated with a mixed Th1 and Th2 gene expression signature. CD4(+) mRNA was diminished in immunosuppression. Skin adjacent to SCC in OTRs showed Th2 expression pattern as compared with immunocompetent patients. T-BET and IFN-gamma mRNA expression were decreased in the OTR group. Although Th17-weighted inflammation was unchanged, IL-17A mRNA level was markedly decreased with immunosuppression. Regulatory T cells, characterized by FOX-P3 and TGF-beta mRNA level, were decreased in OTRs. Our findings support the hypothesis that nontumor-bearing skin adjacent to SCC in OTRs is not necessarily normal and that the local microenvironment may contribute to a field effect contributing to higher recurrence rates and more aggressive behavior observed in these patients