Basosquamous carcinoma: epigenetic considerations in a case

Basosquamous carcinoma (BsC) simulates basal cell carcinoma (BCC) bringing diagnostic difficulties. This infrequent and destructive tumour accounts for 2% of all non-melanoma skin cancers (NMSCs). Studies disclose the destructive properties of the tumor with an occurrence of distant metastases (almost 7.4%) greater than that of squamous cell carcinoma (SCC) [1]. As far as we know, there are no reported comparisons for epigenetic/genetic differences between BsC and healthy cells.
A 68-year-old man presented with a tumoral lesion that slowly enlarged for 6 years and a previous shave biopsy report of BCC. Past medical history revealed diabetes and hypertension with no history of sunburn. Dermatological examination revealed a skin coloured tumoral lesion located on the right ala of the nose measuring 4 cm at the longest diameter. The patient underwent surgical resection of the tumour reconstructed with a nasolabial flap. The flap is opened up from outer edges, bearing 3–4 mm of underlying adipose; then, hinged on its bottom, the flap is flipped over medially like a book page. When the flap is sutured to the along defect proximally, the distal flap is graciously rotated 90° angles and is then folded on itself to create the outer surface of the ala. The histological examination of the surgical specimen revealed BsC with medium desmoplasia and intense lymphohistiocytic infiltration (Figure 1). A piece of tumor taken from the middle of the tumoral lesion was primarily cultured. Human dermal keratinocytes and fibroblasts were grown in KSFM (keratinocyte serum-free medium) and DMEM (Dulbecco’s Modified Eagle Medium) High Glucose medium. Total oxidant status and immunocytochemistry assays for genetic and epigenetic studies were performed in comparison with healthy human dermal fibroblast (HDF) and human epidermal keratinocyte (HEK) cells. Immunocytochemistry (ICC) analysis was performed to study the effect of genetic/epigenetic diversions on disease formation. The cells were incubated with 2% (w/v) paraformaldehyde for 20 min at 4°C for fixation and permeabilized with 0.1% (v/v) Triton X-100 for 5 min and primed in PBS. The cells were incubated with 2% (v/v) goat serum (Sigma, USA) for 10 min at 4°C for avoiding non-specific binding of primary antibodies. Samples were again rinsed three times with PBS [2]. They were incubated overnight with primary antibodies at 4°C. Cells were incubated with rabbit anti-H3AceK36 (1 : 500; Abcam), rabbit anti-H3AceK9 (1 :...


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