Novel somatic Missense Mutations in Exon 11 of the KIT Gene are Detected in Melanoma

OBJECTIVE

The aim of the present study was to analyze mutations of the mast/stem cell growth factor receptor Kit (KIT) gene in patients with melanoma from Eastern Siberia regions of the Russian Federation.

METHODS

KIT gene mutations in exons 11 and 13 were analyzed by Sanger sequencing in 57 tumor samples obtained from patients with KIT-positive melanomas localized in preferable locations.

RESULT

Mutations were identified in 21% of patients. Among them, multiple mutations were identified in five patients. A total of 18 mutations were observed in the KIT gene, of which three were deletions and fourteen substitution mutations. Age, gender and clinicopathological characteristics of patients with cutaneous KIT-positive melanoma in Eastern Siberia corresponded to the European population. According to computational prediction tools, all mutations were evaluated as potentially harmful.

CONCLUSION

The six novel mutations reported in the present study expand our knowledge on the molecular pathogenesis of melanoma, which can be used to further explore methods to improve disease therapeutic strategies.

Effects of Obesity and Calorie Restriction on Cancer Development

The risk of malignant tumor development is increasing in the world. Obesity is an established risk factor for various malignancies. There are many metabolic alterations associated with obesity which promote cancerogenesis. Excessive body weight leads to increased levels of estrogens, chronic inflammation and hypoxia, which can play an important role in the development of malignancies. It is proved that calorie restriction can improve the state of patients with various diseases. Decreased calorie uptake influences lipid, carbohydrate and protein metabolism, hormone levels and cell processes. Many investigations have been devoted to the effects of calorie restriction on cancer development in vitro and in vivo. It was revealed that fasting can regulate the activity of the signal cascades including AMP-activated protein kinase (AMPK), mitogen-activated protein kinase (MAPK), p53, mTOR, insulin/ insulin-like growth factor 1 (IGF1) and JAK-STAT. Up- or down-regulation of the pathways results in the decrease of cancer cell proliferation, migration and survival and the increase of apoptosis and effects of chemotherapy. The aim of this review is to discuss the connection between obesity and cancer development and the mechanisms of calorie restriction influence on cancerogenesis that stress the importance of further research of calorie restriction effects for the inclusion of this approach in clinical practice.

Elevated levels of cytochrome p450scc and 3β-hydroxysteroid dehydrogenase expression in skin of acne vulgaris patients

Background: Acne vulgaris belongs to androgen-dependent diseases where androgens cause sebaceous gland hypertrophy with a subsequent enlargement of sebum production. Aims: Determination of the CYP450scc 3-hydroxysteroid dehydrogenase expression profile in normal skin and skin of patients with acne. Material and methods: Immunohistochemical assay was carried out to evaluate cytochrome P450 side chain cleavage and 3-hydroxysteroid dehydrogenase expression in skin of patients with acne vulgaris and in normal skin. Results: Cytochrome P450 side chain cleavage expression was elevated in epidermal keratinocytes and sebocytes whereas 3-hydroxysteroid dehydrogenase levels were increased in mature sebocytes of acne vulgaris patients. Conclusions: The revealed alterations in expression of steroid-converting enzymes in acne skin may indicate not only the conversion of steroids produced by external steroidogenesis organs but elevated steroids local production as well. The fact may account both for sebaceous gland hyperplasia and inflammation sustenance in skin.

Transcriptomic Profiling Revealed Plexin A2 Downregulation With Migration and Invasion Alteration in Dacarbazine-Treated Primary Melanoma Cells

Melanoma is highly heterogeneous type of malignant neoplasm that is responsible for the majority of deaths among other types of skin cancer. In the present study, we screened a list of differentially expressed genes in two primary, drug-naïve melanoma cell lines derived from patients with melanoma following treatment of the cells with the chemotherapeutic agent dacarbazine. The aim was to determine the transcriptomic profiles and associated alterations in the cell phenotype. We found the vascular endothelial growth factor A/vascular endothelial growth factor receptor 2, phosphoinositide 3-kinase/protein kinase B and focal adhesion signaling pathways to be top altered after dacarbazine treatment. In addition, we observed the expression levels of genes associated with tumor dissemination, integrin β8 and matrix metalloproteinase-1, to be diminished in both cell lines studied, the results of which were confirmed by reverse transcription-quantitative polymerase chain reaction. By contrast, plexin A2 expression was found to be upregulated in K2303 cells, where reduced migration and invasion were also observed, following dacarbazine treatment. Plexin A2 downregulation was associated with the promotion of migrative and invasive capacities in B0404 melanoma cells. Since plexin A2 is semaphorin co-receptor that is involved in focal adhesion and cell migration regulation, the present study suggested that plexin A2 may be implicated in the dacarbazine-mediated phenotypic shift of melanoma cells. We propose that the signature of cancer cell invasiveness can be revealed by using a combination of transcriptomic and functional approaches, which should be applied in the development of personalized therapeutic strategies for each patient with melanoma.

miR-204-5p and miR-3065-5p exert antitumor effects on melanoma cells

MicroRNA (miR)-204-5p was previously identified to be downregulated in melanoma compared with melanocytic nevi. This observation prompted a functional study on miR-204-5p and the newly-identified miR-3065-5p, two miRNAs suggested to be tumor-suppressive oncomiRs. Application of miR-204-5p mimics or inhibitors resulted in a decrease or increase, respectively, in melanoma cell proliferation and colony formation. miR-204-5p mimics hindered invasion, whereas miR-204-5p inhibitors stimulated cancer cell migration. Modulation of miR-3065-5p led to a decrease in melanoma cell proliferation, altered cell cycle distribution and increased expression levels of its target genes HIPK1 and ITGA1, possibly due to functional modifications identified in these cells. miR-204-5p and miR-3065-5p demonstrated antitumor capacities that may need to be taken into account in the development of melanoma treatment approaches.

Melanoma Screening Day in Krasnoyarsk Krai of the Russian Federation: Results from 2015-2016

Objective: The Melanoma Screening Day Campaign started in the Russian Federation in 2006. In the present study, we analyzed the 2015-2016 survey questionnaire data acquired from screened individuals in the city of Krasnoyarsk in eastern Siberia, which has a population of one million, in order to understand the level of awareness regarding melanoma/ skin cancer prevention and early diagnosis. Methods: Individuals were enrolled in the screening campaign by mass media advertising. Free whole-body examinations were provided by the doctors, and the standardized questionnaire forms (n=444) were completed to obtain relevant demographic, epidemiological, and clinical data. Descriptive and univariate analyses were conducted to elucidate the main characteristics of the screened population. Percentage frequency was used to characterize the population. Result: A substantial proportion of the screened individuals were female (80%). The most common reasons for participating in the screening were a high number of moles, or a change in the appearance of the moles. Internet recourses were the main channel for obtaining the information about the Melanoma Day Screening Campaign. 5% of screened individuals had a family history of melanoma/skin cancer. The mean age of the participants was 36.63±16.31 years. The percentage of screened individuals who took part in this program increased in 2016 (18%) versus 2015 (8%). In total, 5 individuals with suspected melanoma/skin cancer were identified during the two-year Campaign, all of whom were referred to the regional oncology center. Conclusion: The analysis of data from the Melanoma Screening Day Campaign in Krasnoyarsk Krai revealed the necessity to use the media to attract older subjects with potential melanoma/skin cancer risk to undergo screening. Individuals with suspected malignancies should be monitored up until the time when a final diagnosis is determined. Moreover, such events are an appropriate way to inform and educate the public about cutaneous cancer prevention.

Antiproliferative and Pro-Apoptotic Effects of MiR-4286 Inhibition in Melanoma Cells

INTRODUCTION

MicroRNAs are essential regulators of gene expression at the post-transcriptional level. Their expression is altered in cancer tissues, and evaluation of these alterations is considered a promising tool used to diagnose and identify prognostic markers.

MATERIALS AND METHODS

The microRNA expression profiles of formalin-fixed, paraffin-embedded melanoma and melanocytic nevi samples were estimated with a microarray and subsequently validated by real-time PCR. Melanoma cells were transfected with miR-4286 inhibitor to evaluate the influence of this microRNA on the viability, proliferation, apoptosis, migration, and invasion of melanoma cells.

RESULTS

The microarray revealed that the expression of 1,171 microRNAs was altered in melanoma samples compared to melanocytic nevi. Real-time PCR validation experiments found the microRNA expression levels to correspond to the melanoma/melanocytic nevi microarray results. The pathway analysis identified 52 modulated pathways in melanoma. Moreover, the application of miR-4286 inhibitor to BRO melanoma cells resulted in a 2.6-fold increase in the apoptosis rate and a 1.7-fold decrease in the cell proliferation/viability but did not affect the invasiveness and migration of these cells. Furthermore, the use of miR-4286 inhibitor altered the mRNA expression of several miR-4286 gene targets: folylpolyglutamate synthase, RNA polymerase I-specific transcription initiation factor, apelin, G-protein-coupled receptor 55, and high-mobility group A1 protein, which have been implicated in cell proliferation/apoptosis regulation. Lastly, the transiently transfected SK-MEL-1 cells with miR-4286 inhibitor decreased proliferation rate and modulated folylpolyglutamate synthase rates of these cells.

CONCLUSION

Our results demonstrate that miR-4286 mediates proliferation and apoptosis in melanoma cells, these findings may represent a novel mechanism underlying these processes.