M. Skrygan

Expression of microRNAs in basal cell carcinoma

Background  Perturbations in the expression profiles of microRNAs (miRNAs) have been reported for a variety of different cancers. Differentially expressed miRNAs have not been systematically evaluated in basal cell carcinoma (BCC) of the skin.

MicroRNAs and the skin: Tiny players in the body's largest organ

MicroRNAs (miRNAs) are very small endogenous RNA molecules about 22-25 nucleotides in length, capable of post-transcriptional gene regulation. miRNAs bind to their target messenger RNAs (mRNAs), leading to cleavage or suppression of target mRNA translation based on the degree of complementarity. miRNAs have recently been shown to play pivotal roles in diverse developmental and cellular processes and linked to a variety of skin diseases and cancers. Disruption of miRNA metabolism is also involved in wound healing and inflammatory skin conditions. Here, we review the role of miRNAs in cutaneous biology.

Differential mRNA Expression of Antimicrobial Peptides and Proteins in Atopic Dermatitis as Compared to Psoriasis Vulgaris and Healthy Skin

Background: Patients with atopic dermatitis (AD) are prone to have skin infections. We aimed to investigate mRNA expression levels of various antimicrobial peptides and proteins (AMPs) in AD patients, and compare it with psoriasis vulgaris (PV) patients and healthy subjects. Methods: Skin biopsies were obtained from healthy subjects and patients with AD and PV. Quantitative real-time RT-PCR was used to determine the mRNA levels of human β-defensin (hBD)-1, hBD-2, hBD-3, LL-37, psoriasin, RNase 7, interferon-γ, and interleukin-10 (IL-10). Results: Except for LL-37, mRNA of hBDs, psoriasin, and RNase 7 was significantly higher expressed in AD (n = 42) and/or PV (n = 35) patients when compared to controls (n = 18). While PV lesions showed significantly higher mRNA hBD-2 levels than lesions of AD, the latter was associated with significantly higher mRNA levels of RNase 7 when compared to PV. A significant positive correlation of hBD expression was observed both in AD patients and PV patients. hBD mRNA levels of AD skin correlated with psoriasin and RNase 7 levels. hBD-1 mRNA expression correlated with AD activity and IL-10 mRNA expression. Conclusions: Most AMPs investigated in this study proved to be overexpressed in AD as well as PV when compared to controls. However, a statistically significant difference in AMP mRNA expression between AD and PV was only found for hBD-2 and RNase 7. A moderate-to-strong linear relationship between the mRNA expression of particular AMPs appears to exist in AD, and to a lesser extent in PV as well.

Comparative microarray analysis of microRNA expression profiles in primary cutaneous malignant melanoma, cutaneous malignant melanoma metastases, and benign melanocytic nevi

Perturbations in microRNA (miRNA) expression profiles have been reported for cutaneous malignant melanoma (CMM) predominantly when examined in cell lines. Despite the rapidly growing number of newly discovered human miRNA sequences, the availability of up-to-date miRNA expression profiles for clinical samples of primary cutaneous malignant melanoma (PCMM), cutaneous malignant melanoma metastases (CMMM), and benign melanocytic nevi (BMN) is limited. Specimens excised from the center of tumors (lesional) from patients with PCMM (n=9), CMMM (n=4), or BMN (n=8) were obtained during surgery. An exploratory microarray analysis was performed by miRNA expression profiling based on Agilent platform screening for 1205 human miRNAs. The results from the microarray analysis were validated by TaqMan quantitative real-time polymerase chain reaction. In addition to several miRNAs previously known to be associated with CMM, 19 unidentified miRNA candidates were found to be dysregulated in CMM patient samples. Among the 19 novel miRNA candidates, the genes hsa-miR-22, hsa-miR-130b, hsa-miR-146b-5p, hsa-miR-223, hsa-miR-301a, hsa-miR-484, hsa-miR-663, hsa-miR-720, hsa-miR-1260, hsa-miR-1274a, hsa-miR-1274b, hsa-miR-3663-3p, hsa-miR-4281, and hsa-miR-4286 were upregulated, and the genes hsa-miR-24-1*, hsa-miR-26a, hsa-miR-4291, hsa-miR-4317, and hsa-miR-4324 were downregulated. The results of this study partially confirm previous CMM miRNA profiling studies identifying miRNAs that are dysregulated in CMM. However, we report several novel miRNA candidates in CMM tumors; these miRNA sequences require further validation and functional analysis to evaluate whether they play a role in the pathogenesis of CMM.

Expression levels of the microRNA maturing microprocessor complex component DGCR8 and the RNA-induced silencing complex (RISC) components argonaute-1, argonaute-2, PACT, TARBP1, and TARBP2 in epithelial skin cancer.

The microprocessor complex mediates intranuclear biogenesis of precursor microRNAs from the primary microRNA transcript. Extranuclear, mature microRNAs are incorporated into the RNA‐induced silencing complex (RISC) before interaction with complementary target mRNA leads to transcriptional repression or cleavage. In this study, we investigated the expression profiles of the microprocessor complex subunit DiGeorge syndrome critical region gene 8 (DGCR8) and the RISC components argonaute‐1 (AGO1), argonaute‐2 (AGO2), as well as double‐stranded RNA‐binding proteins PACT, TARBP1, and TARBP2 in epithelial skin cancer and its premalignant stage. Patients with premalignant actinic keratoses (AK, n = 6), basal cell carcinomas (BCC, n = 15), and squamous cell carcinomas (SCC, n = 7) were included in the study. Punch biopsies were harvested from the center of the tumors (lesional), from healthy skin sites (intraindividual controls), and from healthy skin sites in a healthy control group (n = 16; interindividual control). The DGCR8, AGO1, AGO2, PACT, TARBP1, and TARBP2 mRNA expression levels were detected by quantitative real‐time reverse transcriptase polymerase chain reaction. The DGCR8, AGO1, AGO2, PACT, and TARBP1 expression levels were significantly higher in the AK, BCC, and SCC groups than the healthy controls (P < 0.05). There was no significant difference in the TARBP2 expression levels between groups (P > 0.05). This study indicates that major components of the miRNA pathway, such as the microprocessor complex and RISC, are dysregulated in epithelial skin cancer.

Medium-dose ultraviolet (UV) A1 vs. narrowband UVB phototherapy in atopic eczema: a randomized crossover study

Background  Ultraviolet (UV) A1 and narrowband (NB)‐UVB have been reported to be effective treatments for atopic eczema (AE).

Expression Levels of the microRNA Processing Enzymes Drosha and Dicer in Epithelial Skin Cancer

ABSTRACT Background: Dysregulation of microRNA (miRNA) metabolism has been observed in a variety of human cancers. In this pilot study, we investigated expression profiles of the two most important enzymes of the miRNA machinery, Drosha and Dicer, in relation to epithelial skin cancer and its premalignant stage. Methods: Patients with premalignant actinic keratoses (AK, n = 6), basal cell carcinomas (BCC, n = 15), and squamous cell carcinomas (SCC, n = 7) were included in the study. Punch biopsies were harvested from the center of the tumors (lesional) as well as from sites of healthy skin (intraindividual controls). Skin samples (n = 14) were also obtained from healthy subjects for additional controls. Dicer and Drosha mRNA levels were detected by quantitative real-time reverse transcriptase polymerase chain reaction. Results: Drosha expression levels were significantly upregulated in both the BCC and SCC groups compared to those in the healthy controls (p < .01), while Dicer expression levels in the BCC group were significantly lower (p < .05). Dicer expression in the SCC group was significantly higher compared to intraindividual controls (p < .05), while Dicer expression levels in both the SCC and AK groups were not significantly different from healthy control samples (p > .05). In the premalignant AK group, we could not observe any significant difference in Drosha or Dicer expression levels compared to either healthy or intraindividual controls (p > .05). Conclusions: We observed dysregulation of Drosha and Dicer expression in epithelial tumors when compared to healthy control samples. Therefore, we favor the hypothesis that miRNAs are involved in the carcinogenesis of epithelial skin cancer.

Standardized tape stripping prior to patch testing induces upregulation of Hsp90, Hsp70, IL-33, TNF-α and IL-8/CXCL8 mRNA: new insights into the involvement of 'alarmins'.

Background: The strip patch test is recommended if patch test results are presumed to be false‐negative. It is under discussion whether the cutaneous inflammation induced by tape stripping is a pivotal element in enhancing the allergic contact dermatitis response.

Microarray analysis of microRNA expression in cutaneous squamous cell carcinoma

BACKGROUND MicroRNAs (miRNAs) are a novel class of short RNAs that are capable epigenetically regulating gene expression in eukaryotes. MicroRNAs have been shown to be dysregulated in a variety of cancers. The data on miRNA expression in cutaneous squamous cell carcinoma (cSCC) are very limited, and microarray-based miRNA expression profiles of cSCC have not yet been determined. OBJECTIVE To describe differentially expressed miRNAs in cSCC. METHODS Seven patients with cSCC were enrolled in the present study. Tumor biopsies (n=7) were taken from the center of each tumor. Adjacent healthy skin (n=7) was biopsied as a control (intraindividual control). miRNA expression profiles of all specimens were detected by microarray miRNA expression profiling based on miRBAse 16 scanning for 1205 potential human miRNA target sequences. The microarray results were confirmed by TaqMan quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS Non-stringent filtering with a non-adjusted p ≤ 0.05 revealed thirteen up-regulated and eighteen down-regulated miRNAs. Non-stringent filtering with a non-adjusted p ≤ 0.01 revealed three up-regulated (hsa-miR-135b, hsa-miR-424 and hsa-miR-766) and six down-regulated (hsa-miR-30a*, hsa-miR-378, hsa-miR-145, hsa-miR-140-3p, hsa-miR-30a and hsa-miR-26a) miRNAs in cSCC. CONCLUSION This study reveals differentially expressed miRNAs that may play a role in the molecular pathogenesis of cSCC and that are excellent candidates for further validation and functional analysis.

Loss of 5-hydroxymethylcytosine and ten-eleven translocation 2 protein expression in malignant melanoma.

Several research groups have recently reported on markedly reduced levels of 5-hydroxymethylcytosine (5hmC) in human breast, liver, lung, pancreatic, colon, prostate, brain, and myeloid cancers. We studied benign compound nevi (BCN, n=17), dysplastic compound nevi (DCN, n=15), superficial spreading melanomas [SSM, stratified in <1 mm (n=19) and >4 mm (n=18) Breslow tumor thickness], and cutaneous metastatic disease (CMD, n=24). Immunohistochemistry included specific antibodies against 5hmC, 5-methylcytosine (5mC), and ten-eleven translocation 2 protein (TET2). Immunohistological scoring showed significantly (P<0.0001) higher median 5hmC levels in BCN and DCN than in thin SSM, thick SSM, and CMD. 5mC immunoreactivity did not differ significantly (P=0.15) between nevi and melanoma. The intensity of TET2 expression was predominantly weak but was found to be significantly (P<0.0001) more often in nevi than in thin SSM, thick SSM, and CMD. We have shown that 5hmC levels and TET2 expression are significantly reduced in advanced melanomas compared with nevi and thin melanomas. It is suggested that 5hmC and TET2 possibly play an important role in the epigenetic regulation of melanoma development and progression.