Psoriasis is a chronic skin disease characterized by thickening and disorganization of the skin's protective barrier. Although current models replicate some aspects of the disease, development of therapeutic strategies have been hindered by absence of more relevant models. This study aimed to develop and characterize an in vitro psoriatic human skin equivalent (HSE) using human keratinocytes HaCat cell line grown on fibroblasts-derived matrices (FDM). The constructed HSEs were treated with cytokines (IL-1α, TNF-α, IL-6, and IL22) to allow controlled induction of psoriasis-associated features. Histological stainings showed that FDMHSE composed of a fully differentiated epidermis and fibroblast-populated dermis comparable to native skin and rat tail collagen-HSE. Hyperproliferation (CK16 and Ki67) and inflammatory markers (TNF-α and IL-6) expression were significantly enhanced in the cytokine-induced FDM- and rat tail collagen HSEs compared to non-treated HSE counterparts. The characteristics were in line with those observed in psoriasis punch biopsies. Treatment with all-trans retinoic acid (ATRA) has shown to suppress these effects, where HSE models treated with both ATRA and cytokines exhibit histological characteristics, hyperproliferation and differentiation markers expression like non-treated control HSEs. Cytokine-induced FDM-HSE, constructed entirely from human cell lines, provides an excellent opportunity for psoriasis research and testing new therapeutics.
Oestrogen is important in the development of breast cancer. Oestrogen receptor positive breast cancers are associated with a better prognosis than oestrogen-receptor negative breast cancers since they are more responsive to hormonal treatment. Oestrone sulphate acts as a huge reservoir for oestrogens in the breast. It is converted to the potent oestrogen, oestradiol (E(2)) by the enzymes oestrone sulphatase and oestradiol-17beta hydroxysteroid dehydrogenase (E(2)DH). Retinoic acid and carotenoids have been shown to have chemopreventive activity against some cancers. The aim of our study was to determine and compare the effects of retinoic acid and palm oil carotenoids on growth of and oestrone sulphatase and E(2)DH activities in the oestrogen receptor positive, MCF-7 and oestrogen receptor negative, MDA-MB-231 breast cancer cell lines. Retinoic acid and carotenoids inhibited MCF-7 cell growth but had no effect on MDA-MB-231 cell growth. Both retinoic acid and carotenoids stimulated oestrone sulphatase activity in the MCF-7 cell line. E(1) to E(2) conversion was inhibited by 10(-7) M carotenoids but was stimulated at 10(-6) M in the MCF-7 cell line. Retinoic acid had no effect on E(1) to E(2) conversion at 10(-7) M but stimulated E(1) to E(2) conversion at 10(-6) M. Retinoic acid and carotenoids had no effect on E(2) to E(1) conversion in the MCF-7 cell line. Retinoic acid stimulated E(1) to E(2) conversion in the MDA-MB-231 cell line but had no effect on oestrone sulphatase activity or E(2) to E(1) conversion in this cell line. Both oestrone sulphatase and E(2)DH activity were not affected by carotenoids in the MDA-MB-231 cell line. In conclusion, retinoic acid and carotenoids may prevent the development of hormone-dependent breast cancers since they inhibit the growth of the MCF-7 cell line.
Numerous protocols to establish dopaminergic phenotype in SH-SY5Y cells have been reported. In most of these protocols there are variations in concentration of serum used. In this paper, we compared the effects of high (10%), low (3%) and descending (2.5%/1%) serum concentration in differentiation medium containing different proportion of retinoic acid (RA) and 12-O-Tetradecanoylphorbol-13-acetate (TPA) or RA-only on the undifferentiated SH-SY5Y cells with regards to cell morphology, biochemical and gene expression alterations. Cells differentiated in culture medium containing low and descending serum concentrations showed increased number of neurite projections and reduced proliferation rates when compared to undifferentiated cells. The SH-SY5Y cells differentiated in culture medium containing 3% RA and low serum or descending (2.5%/1% RA/TPA) were found to be more susceptible to 6-hydroxydopamine (6-OHDA) induced cytotoxicity. Cells differentiated with RA/TPA or RA differentiated showed increased production of the α-synuclein (SNCA) neuroprotein and dopamine neurotransmitter compared to undifferentiated cells, regardless serum concentrations used. There was no significant difference in the expression of tyrosine hydroxylase (TH) gene between undifferentiated and differentiated SH-SY5Y cells. However, the expression of dopamine receptor D2 (DRD2) gene was markedly increased (p<0.05) in differentiated cells with 3% serum and RA only when compared to undifferentiated cells. In conclusion, to terminally differentiate SH-SY5Y cells to be used as a cell-based model to study Parkinson's disease (PD) to investigate molecular mechanisms and drug discovery, the optimal differentiation medium should contain 3% serum in RA-only.
There are limited studies on the effects of drugs that modulate epigenetic regulation for head and neck squamous cell carcinoma (HNSCC). This study determined the effect of valproic acid (VPA) on HNSCC.
Breast cancer is the most common cancer in women worldwide. The growth of breast cancer cells is either hormone-dependent or hormone-independent. Both types are represented in vitro by the estrogen-receptor positive (ER+) MCF-7 and the estrogen-receptor negative (ER-) MDA-MB-231 cell lines, respectively. The pS2 gene is an estrogen-regulated gene and serves as a marker for the ER+ tumours. Carotenoids are pigments with anti-cancer properties besides having pro-vitamin A, antioxidant and free-radical quenching effects. This study was designed firstly, to compare the effect of palm oil carotene concentrate with retinoic acid on the growth of the ER+ MCF-7 and the ER- MDA-MB-231 cells; and secondly to evaluate the effect of the palm oil carotene concentrate on the regulation of pS2 mRNA. The growth experiments were performed with monolayer cells seeded in phenol red free RPMI 1640 culture media and subsequently treated with varying concentrations of either retinoic acid or palm oil carotenoids. The cell numbers were determined at the start of each experiment and then at successive time intervals. The results showed that the palm oil carotene concentrate caused dose-dependent inhibition of estradiol-stimulated growth of MCF-7 cells but did not affect the proliferation of MDA-MB-231 cells. Retinoic acid caused similar, albeit more potent effects, as significant inhibition was observed at lower concentrations than the palm oil carotenoids. In the pS2 gene expression experiment, cell monolayers were treated with the carotene concentrate (10(-6) M), either with or without supplemented estradiol (10(-8) M), and subsequently the RNA was extracted. Northern blotting was performed and the regulation of pS2 mRNA determined using a 32P-labelled pS2 cDNA probe. The results showed that the palm oil carotene concentrate did not affect the expression of pS2 mRNA and are therefore independent of the estrogen-regulated pathway.
The growth inhibiting potential of andrographolide was evaluated in three acute promyelocytic leukaemia cell line models (HL-60, NB4 and all-trans retinoic acid (ATRA)-resistant NB4-R2).