Expression and function of NET-1 in human skin squamous cell carcinoma

Jie Zhang,Jing Qin,Xingyu Li,Li Chen,Guilan Wang,Jianli Wang,Yuyin Xu

doi:10.1007/s00403-013-1423-9

Abstract

To evaluate the clinicopathological significance of NET-1 in human skin squamous cell carcinoma (SSCC). The expression of NET-1 and Ki67 protein was detected using immunostaining from 60 SSCC cases, 50 SIN samples and ten normal skin tissues. The vectors expressing NET-1, siRNA NET-1 and shRNA NET-1 were constructed, as well as negative controls (target-off). In transfected A431 cells, the expression of NET-1 was detected by qRT-PCR, Western blot and immunofluorescence staining; the proliferation and migration of cells was evaluated by MTT, flow cytometry, wound healing and transwell chamber assays. The stable cell lines transfected with shRNANET-1 was inoculated in nude mice for in vivo study. (1) The levels of NET-1 were significantly higher in SSCC (96.67 %) and SIN III (93.75 %) than that in SIN I and II (41.18 %), (P < 0.05). NET-1 expression was significantly enhanced in spindle-cell SSCC (75 %) versus other histological types (P < 0.05). (2) The expression of NET-1 in A431 cells transfected with siRNANET-1 or shRNANET-1 was significantly decreased; the proliferation and migration of these cells were obviously inhibited as compared to controls (P < 0.05). (3) The growth of subcutaneous tumors was significantly inhibited associated with reduction in the expression of NET-1 vs. the negative control or untreated group (P < 0.05). The overexpression of NET-1 in tumor cells may be closely related to the malignant phenotype of SSCC. NET-1 RNAi used in this study can specifically and effectively downregulate NET-1 gene expression; thus SSCC proliferation, invasion and tumor growth were attenuated. NET-1 might be one of the potential targets for SSCC therapy.

Highlights

Skin squamous cell carcinoma (SSCC) is among the top three common skin cancers, ranking behind basal cell carcinoma (BCC) and ahead of melanoma
The clinicopathological features were determined according to WHO histological classification of keratinocytic skin tumors and TNM stage of skin carcinomas [6, 15]
SSCC cases were divided into general SSCC (31 cases, 51.67 %), acantholytic SSCC (10 cases, 16.67 %), spindle-cell SSCC (8 cases, 13.33 %), verrucous SSCC (9 cases, 15 %), and other types (2 cases, 3.33 %)

Summary

Introduction

Skin squamous cell carcinoma (SSCC) is among the top three common skin cancers, ranking behind basal cell carcinoma (BCC) and ahead of melanoma. SSCC is a significant public health problem despite their low mortality rate [23]. A number of potentially useful molecular markers or tests have been proposed, these include some novel genes and proteins closely related to the carcinogenesis, development and prognosis [11, 16, 22], which may be of great significance for early diagnosis and treatment of SSCC. NET-1 (or TSPAN1, TSPAN1/C4-8, Gene ID: 10103) and NET2-7 are called NET-X, which are members of seven transmembrane four superfamily (TM4SF) found by Serru in 2000 in EST database [25, 27] TM4SF is a group of proteins containing four hydrophobic transmembrane domains forming two extracellular loop structures with different size. TM4SF members have increased to 25, their amino acid sequence share a high homology, there are significant differences between different tissues and cells, the recently reported

Methods

Results

Conclusion