The Role of Stem Cell Factor in Hyperpigmented Skin Lesions.

BACKGROUND: Skin hyperpigmentation usually results from an increased number, or activity, of melanocytes. The degree of pigmentation of skin depends on the amount and type of melanin, degree of skin vascularity, presence of carotene, and thickness of the stratum corneum. Common causes of hyperpigmentation include post-inflammatory hyperpigmentation, melasma, solar lentigines, ephelides (freckles), and café-au-lait macules. Some skin tumors can be hyperpigmented as basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and malignant melanoma (MM). Stem cell factor (SCF) is a growth factor and its interaction with its receptor, c-kit, is well known to be critical to the survival of melanocytes. METHODS: This study was carried out on 60 patients complaining of hyperpigmented skin lesions (20 melasma, 20 solar lentigines, and 20 freckles) and 36 patients with skin tumors (14 BCC, 12 SCC, and 10 MM). Punch skin biopsies were taken from the previous lesions. Immunohistochemical staining of these samples was done using the stem cell factor (SCF). RESULTS: There was positive expression of SCF in all cases of melasma, solar lentigines and freckles with significant increase in the intensity of expression in the lesional areas than the non-lesional ones (P=0.004). There was also a statistically significant increase in the expression of SCF in BCC and melanoma tumor cells. CONCLUSION: SCF has a great role in skin hyperpigmented disorders and this can be used as a target for the developing of new antipigmentary lines of treatment by inhibiting SCF. SCF can also be involved in the emergence of some skin tumors.

The prognostic value of sex hormone receptors expression in laryngeal carcinoma.

Laryngeal cancer was identified as the second most common respiratory system malignancy with squamous cell carcinoma being the most common malignant tumor of the larynx. Larynx being a secondary sex organ showing physiological changes during puberty, raises inquiry about the relationship between sex hormones receptors as estrogen receptors (ER), progesterone receptors (PR), androgen receptors (AR) and the development of laryngeal carcinoma. This study was carried out in cancer tissue samples from 50 patients with laryngeal squamous cell carcinoma. Immunohistochemical staining using ER-ß, PR, and AR was carried out. The immunohistochemical expression of ER-ß, PR and AR was positive in 56%, 50% and 64% of cases respectively. ER-ß, and PR expression were significantly higher in poorly differentiated cases and cases with lymphatic invasion while AR expression was significantly lower in poorly differentiated cases and with lymphatic invasion. In conclusion, ER-ß and PR may be considered as markers for poor biological behavior of laryngeal carcinoma.

Effect of atorvastatin and methotrexate on solid Ehrlich tumor.

Hydroxymethyl glutaryl CoA reductase is the key enzyme in cholesterol synthesis. A relationship was found between cholesterol and the development of many types of cancer. Atorvastatin is a hypolipidemic drug that may have a role in treatment of cancer. Moreover, atorvastatin was reported to decrease the resistance of cancer cells to many chemotherapeutic agents. The aim of this work was to study the effect of each of methotrexate (MTX) and atorvastatin alone and in combination on solid Ehrlich carcinoma (SEC) in mice. Fifty BALB/c mice were divided into five equal groups: control untreated group, SEC, SEC+MTX, SEC+atorvastatin, SEC+MTX+atorvastatin. Tumor volume, tissue glutathione reductase (GR), catalase, malondialdehyde (MDA), cholesterol and tumor necrosis factor alpha (TNF-α) were determined. A part of the tumor was examined for histopathological and immunohistochemical study. MTX or atorvastatin alone or in combination induced significant increase in tissue catalase and GR with significant decrease in tumor volume, tissue MDA, cholesterol and TNF-α and alleviated the histopathological changes with significant increase in p53 expression and apoptotic index compared to SEC group. In conclusion, the combination of MTX and atorvastatin had a better effect than each of MTX or atorvastatin alone against solid Ehrlich tumor in mice.