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.