Expression of silent information regulator 1 and 3 and hypoxia-inducible factor 1α in cutaneous squamous cell carcinoma tissues and cells / 中华皮肤科杂志

ABSTRACT

Objective:To determine the expression of silent information regulator 1 (Sirt1) , Sirt3 and hypoxia-inducible factor 1α (HIF-1α) in cutaneous squamous cell carcinoma (CSCC) tissues and cells, and to explore their role in the occurrence and development of CSCC.Methods:From January 2019 to December 2020, 30 lesional skin tissues were obtained from patients with histopathologically confirmed poorly-, moderately- or well-differentiated CSCC, and 30 normal skin tissues were obtained from patients with non-cancerous diseases in Department of Dermatology, General Hospital of Ningxia Medical University. A CSCC cell line A431 and a human keratinocyte cell line HaCaT were cultured. Immunohistochemical study, Western blot analysis and real-time quantitative PCR (RT-PCR) were performed to determine the protein and mRNA expression of Sirt1, Sirt3 and HIF-1α in CSCC tissues of different grades of differentiation and normal skin tissues, cytochemical and immunofluorescence staining and RT-PCR were conducted to determine the protein and mRNA expression of Sirt1, Sirt3 and HIF-1α in A431 and HaCaT cells, respectively. Comparisons of measurement data among multiple groups were performed by using one-way analysis of variance, and comparisons between two groups by using t test. Results:Immunohistochemical study showed that the expression level of Sirt3 (expressed as the average optical density) was 100 ± 12.12, 117.72 ± 26.23, 127.32 ± 24.45, 132.71 ± 31.61 in the normal skin tissues and well-, moderately- and poorly-differentiated CSCC tissues respectively, and there was a significant difference among these groups ( F = 20.14, P < 0.001) ; the expression of Sirt1 and HIF-1α increased in turn from the normal skin tissues to the well-, moderately- and poorly-differentiated CSCC tissues, and significantly differred in these groups ( F = 174.50, 225.00, respectively, both P < 0.001) . As Western blot analysis revealed, the expression level of Sirt3 significantly differed among the normal skin tissues, well-, moderately- and poorly-differentiated CSCC tissues (expressed as relative gray value 1.000 ± 0.132, 1.403 ± 0.411, 1.387 ± 0.393, 1.677 ± 0.683, respectively; F = 34.97, P < 0.001) , and so did the expression levels of Sirt1 and HIF-1α ( F = 69.29, 199.90, respectively, both P < 0.00l) , with a gradually increasing trend in their expression levels from the the normal skin tissues to well-, moderately- and poorly-differentiated CSCC tissues. RT-PCR showed that the mRNA expression of Sirt3, Sirt1 and HIF-1α was sequentially increased from the normal skin tissues to well-, moderately- and poorly-differentiated CSCC tissues, and significant differences were observed among these groups ( F = 113.00, 174.50, 50.33, respectively, all P < 0.001) . The protein expression levels of Sirt3, Sirt1 and HIF-1α were significantly higher in the A431 cells than in the HaCaT cells ( t = 16.75, 18.34, 27.76, respectively, all P < 0.001) , and so were their mRNA expression levels ( t= 14.22, 9.62, 16.86, respectively, all P < 0.001) . Conclusion:Increased expression of Sirt3, Sirt1 and HIF-1α was observed in CSCC tissues and cells, which may promote the occurrence and development of CSCC.