Studies On The LCE3C Expression In Human Skin Cancers And The Potential Regulation Mechanisms

Background and ObjectiveSkin cancer is one of the six most common kinds of cancers, there are two common pathological classification of skin cancer:squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). More and more evidences showed that the morbility of skin cancers has been increasing in recent years. Some patients with skin cancers died from metastasis and invasion. Comparing with skin cancers and psoriasis, there are some common pathological characteristics:such as excessive hyperplasia of epidermis, epidermis parakeratosis. Previous studies proved that epidermal specific markers, such as late keratinization envelope protein (LCE3C) was over expressed in psoriatic skins comparing to the normal skins. LCE3C, as an adhesion molecule in the extracellular matrix, plays an important role in the epidermal barrier protection. GRHL3 also known as Get1, as a transcription factor, promotes keratinocytes migration from the epidermal basal layer to epidermal layers during normal epidermal formation. However, it is unclear for GRHL3 to involved in the pathogenesis of skin cancer. Therefore, it may be necessary for us to investigate cellular localization and functions of LCE3C, and to study correlation between GRHL3 and LCE3C in skin cancers.Methods1. HE staining was performed to detect the morphological differences between skin squamous carcinoma tissues, basal cell carcinoma tissues and normal skin tissues.2. The immunohistomistry was used to detect the LCE3C expression in skin squamous cell carcinoma tissues and basal cell carcinoma tissues, the normal skin tissues.3 GFP and LCE3C fusion expression vector was obtained using gene engineering methods.4. The recombinant expression vector pLCE3C-GFP, pGFP was transfected to human skin squamous cancer cell line, A431, respectively.5. Cellular localization of LCE3Cwas observed under the laser confocal microscopy.6. Western blot analysis was performed to detect expression of the interest proteins, including LCE3C and GRHL3. 7. MTT analysis was used to test cell proliferation.8. Wound healing was used to investigate cells nick healing ability.Results1. Compared with normal skin tissues, HE staining results showed that hierarchical boundaries disappeared, the base layer and the stratum spinosum was much thicker in squamous cell carcinoma tissues and basal cell carcinoma tissues.2. Immunohistochemical results showed that LCE3C was predominantly expressed in the epidermis cutin layers, and LCE3C expression in SCC and BCC was significantly increased compared to the normal skin tissues.3.LCE3C was seen at extranuclearof the A431 cells under the laser confocal microscope.4. Western blot results showed that GRHL3 expression level was decreased significantly in A431 cells, compared to a keratinocyte cell line (HaCaT), while LCE3C expression level was increased obviously; LCE3C expression level was significantly reduced in the A431 cells with GRHL3overexpression (A431/GRHL3).5. MTT analysis showed that cell proliferation rate of the A431/LCE3C-GFP cells was significantly increased at 12 h,24 h,48 h compared with the A431 cell.6. According to wound healing analysis, cell nick healing ability of the A431/LCE3C-GFPwas significantly decreased, compared with the controls.Conclusion1. Compared with normal skin tissues, LCE3C expression increased in skin cancer, and mainly distributed at extranuclearof skin cutin layers; 2. The expression level of transcription factor GRHL3 and LCE3C in A431 cells show the negative correlation.3. To some extent, LCE3C could inhibit cell proliferation and cell nick healing ability.