The Level of TWIST1 expression determines the response of colon cancer cells to mitogen-activated protein kinases inhibitors.

Background/Aim: Currently, it has been proposed that combination of 5-fluorouracil (5FU) with inhibitors of the mitogen-activated protein kinases (MAPKs) signaling pathway might enhance the efficacy of 5FU-based chemotherapy in colon cancer. Our study aimed to investigate an impact of TWIST1 silencing on the sensitivity of cancer cells to 5FU and selected MAPK inhibitors. Materials and Methods: The suppression of TWIST1 expression in human colon cancer HT29 and HCT116 cell lines was achieved by transduction with lentiviral vector carrying the TWIST1 silencing sequence (pLL3.7-sh TWIST1). The statistical calculation was performed with analysis of variance or Dunnett's test for comparison to control group. Paired Student's t-test was performed when two groups were analyzed. Results: Suppression of TWIST1 reduced the proliferation rate of colon cancer cells and enhanced their sensitivity to 5FU and MAPKs inhibitors. The sensitivity of HT29 cells to examined compounds was more dependent on TWIST1 expression level compared to HCT116 cells. The most noticeable effect of TWIST1 suppression on sensitivity of both colon cancer cell lines to combined treatment of 5FU and the MAPKs inhibitors was observed for inhibitors of p38α/ß and JNK1-3. We also noted that the suppression of TWIST1 significantly sensitized both cell lines to combined treatment of 5FU and Rac inhibitor. Conclusions: Our observations point to TWIST1 expression level as a marker of colon cancer sensitivity to combined treatment of 5FU and MAPKs inhibitors.

Altered Expression of Genes Encoding Cornulin and Repetin in Atopic Dermatitis.

BACKGROUND: It is assumed that beside alterations in the filaggrin gene (FLG), disturbances within genes encoding other cornified envelope proteins are also involved in atopic dermatitis (AD). To identify new potential markers of AD, we studied the polymorphisms of genes encoding repetin (RPTN), cornulin (CRNN), and their expression in the skin of AD patients. METHODS: Polymorphisms in CRNN (rs941934), RPTN (rs284544, rs28441202, rs3001978, and rs12117644), and FLG mutations (R2447X, S3247X) were analyzed by TaqMan genotyping assay and by PCR-RFLP in the blood samples of 159 AD patients and 108 healthy subjects. The expression levels of CRNN and RPTN were determined by qRT-PCR in 34 AD skin samples (17 lesional and 17 nonlesional) and in 27 skin biopsies from healthy volunteers. The AD patients were recruited from the clinic of the university hospital between 2012 and 2014. RESULTS: CRNN rs941934 (A allele) was associated with AD (OR 2.095, p = 0.008), a severe course of disease (p = 0.041), elevated IgE levels (p = 0.047), eosinophilia (p = 0.018), and concomitant asthma (p = 0.004). The mRNA level of CRNN was decreased in the AD skin (p = 0.041). In the AD patients without FLG mutations, the CC genotype of RPTN rs3001978 was associated with AD (OR 0.39, p = 0.037), early age at onset (p = 0.033), pruritus (p = 0.021), severity of AD (p = 0.045), and concomitant asthma (p = 0.041). The elevated mRNA levels of RPTN in lesional (p < 0.001) and nonlesional (p = 0.017) AD skin were observed. CONCLUSIONS: The single-nucleotide polymorphisms of CRNN (rs941934) and RPTN (rs3001978, rs28441202) may contribute to AD development, but further studies on a larger group of AD patients are needed to verify this assumption.

Expression of Cornified Envelope Proteins in Skin and Its Relationship with Atopic Dermatitis Phenotype.

Changes in the expression of cornified envelope (CE) proteins are thought to affect the development and course of atopic dermatitis (AD). The aim of this study was to examine the expression level of CE proteins in order to identify new molecular markers of the AD phenotype. Expression levels of CE proteins were evaluated in the skin of patients with AD (38 biopsies) and healthy subjects (26 biopsies). Levels of FLG, FLG2 and SPRR3 mRNAs and proteins were reduced in AD skin. Levels of LELP-1 and SPRR1A transcripts and proteins were significantly increased in AD skin. SPRR3v2 mRNA level in non-lesional AD skin correlated with severity of AD, and SPRR3 protein level in non-lesional AD skin correlated inversely with pruritus. FLG protein level in AD skin correlated inversely with severity of AD. These results point to SPRR3 as an important factor in AD and itch.

Suppression of TWIST1 enhances the sensitivity of colon cancer cells to 5-fluorouracil.

The 5-fluorouracil (5FU)-based adjuvant chemotherapy improves the survival of patients with colorectal cancer, however the main obstacle affecting its effectiveness is a drug resistance. Our study aimed to investigate the impact of TWIST1 silencing on the sensitivity of cancer cells to 5FU. The suppression of TWIST1 expression in human colon cancer HT29 and HCT116 cell lines was achieved by transduction with lentiviral vector carrying the TWIST1 silencing sequence (pLL3.7-shTWIST1). The suppression of TWIST1 expression induced changes in the expression pattern of epithelial to mesenchymal transition markers, reduced the cells proliferation rate, increased their sensitivity to serum withdrawn, and increased the cytotoxic effect of 5FU. However, significantly higher 5FU cytotoxicity was observed in HT29 cell cultures. Cells with silenced TWIST1 displayed altered expression of enzymes metabolizing 5FU. The expression level of dihydropyrimidine dehydrogenase, and thymidylate synthase decreased significantly in HT29 shTWIST1 cells, but not in HCT116 shTWIST1 cells. On the other hand, significant increases in the expression levels of thymidine phosphorylase, and uridine phosphorylase 1 were seen in both cell lines with suppressed expression of TWIST1. The changes in enzymes expression were mirrored by enzymatic activities. In conclusion, our observations point to TWIST1 as a target protein to enhance the sensitivity of colorectal cancer cells to 5FU.

Association of a Single Nucleotide Polymorphism in a Late Cornified Envelope-like Proline-rich 1 Gene (LELP1) with Atopic Dermatitis.

There is some evidence that genes involved in the pathogenesis of atopic dermatitis, in addition to the filaggrin (FLG) gene, may be located at chromosome region 1q21. The aim of this study was to examine the association of single nucleotide polymorphisms in the region of the late cornified envelope-like proline-rich 1 (LELP1), hornerin (HRNR) and FLG genes with the course and risk of atopic dermatitis. Single nucleotide polymorphisms and mutations were genotyped by PCR restriction fragment length polymorphism and real-time PCR in a group of 152 patients with atopic dermatitis and 104 healthy volunteers. CC genotype and C-allele of LELP1 rs7534334 were found in patients with atopic dermatitis and were associated with elevated levels of serum immunoglobulin E, severity of atopic dermatitis and concomitant asthma. LELP1 rs7534334 enhanced the risk of atopic dermatitis nearly 2.5-fold. This pilot study suggests that rs7534334 SNP, located in the LELP1 region, may be a potential genetic marker for the risk and course of atopic dermatitis.

Differentiation of high-risk stage I and II colon tumors based on evaluation of CAV1 gene expression.

BACKGROUND: Several molecular markers are currently being investigated for their prognostic or predictive value in colorectal cancer. One of the genes proposed, as a potential molecular marker in CRC is CAV1. METHODS: The level of CAV1 expression was investigated in low-stage (I and II TNM) colon cancers using Real-Time PCR and immunohistochemistry. RESULTS: The level of CAV1 expression increased in tumors characterized by greater depths of invasiveness. The CAV1 expression level detected in tumors with a depth of invasion at stage T4 was significantly higher compared to that in T2 (P = 0.01) and T3 (P = 0.003) lesions. The length of a patient's survival depended on CAV1 expression level; the 10-year survival rate for patients with elevated expression of CAV1 was ∼59% compared with 91% for patients with reduced or unchanged expression of CAV1 (P = 0.007). The overall survival rate of patients with T3 + T4 lesions was significantly lower (P = 0.006) for patients with tumor displaying elevated CAV1 expression compared with patients with reduced or unchanged CAV1 expression. CONCLUSIONS: Evaluation of CAV1 expression offers valuable prognostic information for patients with colorectal cancer, and could be used to select patients with stage I or II disease, who are at increased risk of unfavorable outcomes.

Altered response of fibroblasts from human tympanosclerotic membrane to interacting mast cells: implication for tissue remodeling.

Several lines of evidence suggest that a tympanosclerotic (TMS) lesion often develops secondary to acute and chronic otitis media. Histological findings indicate that fibroblasts and inflammatory cells, including mast cells, play a key role in the tympanosclerotic plaque formation. However, details on the functional characteristics of tympanosclerotic fibroblasts (Fs(TMS)) are scanty. Therefore the aim of our study was to examine the activity of human fibroblasts from tympanosclerotic lesions and to evaluate the influence of stimulated by crosslinking of IgE receptor mast cells (HMC-1(FcɛRI)) on fibroblast functional behavior. We observed that fibroblasts from normal tympanic membrane (Fs(TM)) released less TNF-α, TGF-ß1 and IL-6 compared to Fs(TMS). Fs(TMS) but not Fs(TM) upon interaction with HMC-1(FcɛRI) released increased quantities of TNF-α and TGF-ß1. Exposing the fibroblast to HMC-1(FcɛRI) cells resulted in an increased synthesis of proteins including collagen. We noted that the COL2A1 transcript level increased ∼5- and ∼12-fold in Fs(TM) and Fs(TMS) co-cultured with HMC-1(FcɛRI), respectively. Both Fs(TM) and Fs(TMS) upon maintenance in the primary culture released significant quantities of matrix metalloproteinase 9 (MMP-9). However, Fs(TMS) released ∼5-fold more MMP-9 activity compared to the Fs(TM) cultures. The mast cell-induced release of TNF-α, TGF-ß1 and MMP-9 sustained for a longer time in Fs(TMS) cultures compared to Fs(TM). Concluding, our data strongly indicate that increased fibroblast sensitivity to mast cell stimulation greatly contributes to the excessive fibrosis and pathological remodeling of the tympanic membrane. We postulate that the persistency of the Fs(TMS) activated state could be an important factor in the pathogenesis of tympanosclerosis.