RESUMEN
Cutaneous squamous cell carcinoma (CSCC) is one of the most common types of skin cancer in humans worldwide. The identification and characterization of cancer-associated transmembrane proteins are important for understanding the molecular biology of CSCC. The aim of the present study was to evaluate the expression pattern of transmembrane protein 40 (TMEM40) in CSCC and its clinical significance. The underlying mechanisms were also examined. Reverse transcription-quantitative PCR, western blot and immunohistochemistry analysis were used to determine the relative expression of TMEM40 in CSCC cell lines and clinical tissue samples. The effect of TMEM40 gene silencing on cell proliferation was also evaluated using Cell Counting Kit-8 assays. Wound healing assays, flow cytometry and Transwell assays were used to explore the migration, cell cycle distribution/apoptosis and invasion of CSCC cells following TMEM40 silencing, respectively. In the present study, increased TMEM40 expression was observed in CSCC tissue samples, compared with normal skin, and TMEM40 expression was associated with large tumor size in patients with CSCC. In vitro functional assays indicated that TMEM40 was involved in the regulation of A431 and SCL1 cell growth through its effects on the cell cycle and apoptosis. Silencing TMEM40 in A431 and SCL1 cells resulted in cell cycle arrest at the G0/G1 phase and promoted apoptosis. In addition, migration and invasion were significantly inhibited following silencing of TMEM40 expression in CSCC cells. Taken together, the results of the present study indicated that reduced TMEM40 expression could inhibit CSCC development and that TMEM40 may represent a therapeutic target in CSCC.
RESUMEN
Congenital hemidysplasia with ichthyosiform nevus and limb defects (CHILD) syndrome is an X-linked autosomal dominant disorder characterized by unilateral congenital hemidysplasia with ichthyosiform erythroderma and ipsilateral limb defects caused by a mutation in the gene encoding NAD[P]H steroid dehydrogenase-like protein (NSDHL) at Xq28. The histopathologic hallmark of skin lesions in CHILD syndrome is psoriasiform epidermis with hyperkeratosis and parakeratosis, and its most striking feature affecting the upper dermis is filling of the papillary dermis with foam cells. Here we present the case of a 9-year-old Chinese girl born with the typical clinical features of CHILD syndrome. Histologic and immunohistochemical evaluation of the skin lesions confirmed the diagnosis and led to identification of a heterozygous point mutation in exon 8 of the NSDHL gene. In addition, we provide a literature review of 26 unrelated CHILD syndrome patients from different countries, caused by 20 unique gene mutations occurring throughout the entire NSDHL gene, to promote understanding and provide a more comprehensive description of this unusual disorder.
