Genomic instability in radial growth phase melanoma cell lines after ultraviolet irradiation

4D Biofabrication: Materials, Methods, and Applications

The mission of regenerative medicine is the development of methods to regrow, repair, or replace damaged or diseased cells, organs, or tissues. 3D bioprinting techniques are one of the most promising approaches for engineering the design of artificial tissues. Current 3D bioprinting technologies possess, however, several intrinsic limitations. 4D biofabrication, a recently developed technology with the embedded ability of shape transformation upon response to intrinsic and/or external stimuli, may solve challenges of 3D bioprinting as well as more accurately mimic the dynamics of the native tissues. This article covers recent advances in 4D biofabrication. It gives a detailed picture of used materials and technologies, provides critical comparisons of methods, discusses possibilities and limitations of different 4D biofabrication technologies, and gives examples of applications.

Origanum vulgare mediated green synthesis of biocompatible gold nanoparticles simultaneously possessing plasmonic, antioxidant and antimicrobial properties

Purpose

The leaves and flowering stem of Origanum vulgare contain essential oils, flavonoids, phenolic acids and anthocyanins. We propose a new, simple, one-pot, O. vulgare extract (OVE) mediated green synthesis method of biocompatible gold nanoparticles (AuNPs) possessing improved antioxidant, antimicrobial and plasmonic properties.

Materials and methods

Different concentrations of OVEs were used to reduce gold ions and to synthetize biocompatible spherical AuNPs. Their morphology and physical properties have been investigated by means of transmission electron microscopy, ultraviolet-visible absorption spectroscopy, photon correlation spectroscopy and Fourier transform infrared spectroscopy, whereas their plasmonic properties have been tested using surface-enhanced Raman spectroscopy (SERS). The antioxidant properties of nanoparticles (NPs) have been evaluated by 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, and the antimicrobial tests were performed using the disk diffusion assay. Their cytotoxicity has been assessed by means of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.

Results

The experimental results confirmed the successful synthesis of biocompatible, spherical, plasmonic NPs having a mean diameter of ~40 nm and an outstanding aqueous stability. This new class of NPs exhibits a very good antioxidant activity and presents interesting inhibitory effects against Staphylococcus aureus and Candida albicans. Due to their plasmonic properties, AuNPs are used as SERS substrates for the detection of a test molecule (methylene blue) up to a concentration of 10^-7 M and a pharmaceutical compound (propranolol) in solution. Cytotoxicity assays revealed that AuNPs are better tolerated by normal human dermal fibroblast cells, while the melanoma cancer cells are more sensitive.

Conclusion

The biocompatible AuNPs synthetized using OVEs showed significant bactericidal and antimycotic activities, the most sensitive microorganisms being S. aureus and C. albicans, both commonly involved in various dermatological infections. Moreover, the significant antioxidant effect might recommend their use for protective and/or preventive effect in various skin inflammatory conditions, including the reduction in side effects in dermatological infections. Meanwhile, the as-synthesized biocompatible AuNPs can be successfully used as SERS substrates for the detection of pharmaceutical compounds in aqueous solutions.

CXCR3 signaling in BRAFWT melanoma increases IL-8 expression and tumorigenicity

Patients with early stage, radial growth phase (RGP) melanoma have a 97% survival rate; however, when the melanoma progresses to the invasive vertical growth phase (VGP), survival rates decrease to 15%. The targets of many clinical trials are the known genetic and molecular mechanisms involved in melanoma progression, with the most common oncogenic mutation being the BRAF^V600E. However, less than half of melanomas harbor this mutation, and consequently, do not respond to the current BRAF targeted treatments. It is therefore critical to elucidate alternative mechanisms regulating melanoma progression. Increased expression of the chemokine receptor, CXCR3, on melanoma cells is correlated with increased metastasis and poor patient outcomes, suggesting a role for CXCR3 in the RGP to VGP transition. We found that endogenous CXCR3 can be induced in two RGP cell lines, BOWES (BRAF^WT) and WM35 (BRAF^V600E), with in vitro environmental stress and nutrient deprivation. Signaling via induced endogenous CXCR3 is linked with IL-8 expression in BOWES cells. Ectopic overexpression of CXCR3 in BOWES cells leads to increased ligand-mediated phERK, cellular migration, and IL-8 expression in vitro, and to increased tumorigenesis and lymph node metastasis in vivo. Our results demonstrate that, in BRAF^WT melanomas, CXCR3 signaling mediates significant increases in IL-8 expression, suggesting that CXCR3 expression and signaling may represent a transformative event that drives the progression of BRAF^WT melanomas. Implications: Expression of CXCR3 on BRAF^WT melanoma cells may be a mediator of melanoma progression.

DNA profiling and characterization of animal cell lines

The history of the culture of animal cell lines is littered with published and much unpublished experience with cell lines that have become switched, mislabelled, or cross-contaminated during laboratory handling. To deliver valid and good quality research and to avoid waste of time and resources on such rogue lines, it is vital to perform some kind of qualification for the provenance of cell lines used in research and particularly in the development of biomedical products. DNA profiling provides a valuable tool to compare different sources of the same cells and, where original material or tissue is available, to confirm the correct identity of a cell line. This chapter provides a review of some of the most useful techniques to test the identity of cells in the cell culture laboratory and gives methods which have been used in the authentication of cell lines.

Differential gene hypermethylation in genital lichen sclerosus and cancer: a comparative study

AIMS

Lichen sclerosus (LS) is a chronic inflammatory disease of the genital skin of unknown aetiology. The role of LS in penile squamous cell carcinogenesis is not well characterized. HPV has been implicated in both, as have epigenetic changes. The presence of HPV and hypermethylation of the MGMT, p16, RASSF1, RASSF2, TSLC1 and TSP1 genes were studied in penile LS; MGMT, RASSF2 and TSLC1 hypermethylation in penile cancer and TSLC1 hypermethylation in vulvar LS and cancer extends previous results reported by our group.

METHODS AND RESULTS

Thirty-seven HPV genotypes and hypermethylation were evaluated by PCR/reverse-line-blot and methylation-specific PCR respectively, in 27 preputial LS, 24 penile SCC, 30 vulvar SCC, 21 vulvar LS and 22 normal skin cases. HPV66 was present in 3.7% of penile LS cases, and p16 and RASSF2 hypermethylation were more frequent in penile cancer than in penile LS. p16, RASSF1, RASSF2 and TSP1 hypermethylation were similar in penile and vulvar LS.

CONCLUSIONS

Gene hypermethylation is a common event in penile LS, and occurs approximately as frequently as in vulvar LS. Certain genes can be hypermethylated as an early or late event in LS or cancer, respectively. This suggests a possible sequential role for these alterations in the transition from benign to malignant lesions.

Molecular Network Associated with MITF in Skin Melanoma Development and Progression

Various environmental and genetic factors affect the development and progression of skin cancers including melanoma. Melanoma development is initially triggered by environmental factors including ultraviolet (UV) light, and then genetic/epigenetic alterations occur in skin melanocytes. These first triggers alter the conditions of numerous genes and proteins, and they induce and/or reduce gene expression and activate and/or repress protein stability and activity, resulting in melanoma progression. Microphthalmia-associated transcription factor (MITF) is a master regulator gene of melanocyte development and differentiation and is also associated with melanoma development and progression. To find better approaches to molecular-based therapies for patients, understanding MITF function in skin melanoma development and progression is important. Here, we review the molecular networks associated with MITF in skin melanoma development and progression.

Thinking about the role (largely ignored) of heavy metals in cancer prevention: hexavalent chromium and melanoma as a case in point

Ultraviolet (UV) light exposure accounts for only 40-50% of the attributable risk for cutaneous melanoma (CM); also classical UV-induced lesions are rare in melanomas (especially among CM with NRAS or BRAF mutations). It is therefore likely that an additional environmental factor exists as familial and genetic factors play a role in less than 5%. A large amount of (largely forgotten) epidemiologic data indicates that heavy metal exposure is strongly associated with the development of CM. Also, epidemiologic studies of patients with joint replacement indicate a marked subsequent time-related increase in melanoma in patients with metal-on-metal hip arthroplasties. In these patients chromium and cobalt levels rise to 10x normal and stay elevated at levels two- to threefold normal for at least 10 years. Chromium is widely used in industry for its anticorrosive and steel-strengthening properties and is widespread in everyday materials. Our hypothesis is therefore that chromium, alone or in conjunction with UV, plays a major role in the pathogenesis of CM. We have incubated human neonatal melanocytes for more than 10 weeks in the presence of a wide range and concentrations of metals without effect except by hexavalent chromium Cr(VI)and to a lesser degree Co²(+). After prolonged culture, chromium-incubated cells produced foci and when replated secondary colonies formed. We have just begun to study this phenomenon in more detail and studies without and with different wavelengths of UV will be explored. Of interest is that aneuploidy (a universal chromosomal change in cutaneous melanoma) in lymphocytes in patients with hip-on-hip metal prostheses has been demonstrated by others.

Cellular and sub-cellular responses to UVA in relation to carcinogenesis

PURPOSE

UVA radiation (315-400 nm) contributes to skin aging and carcinogenesis. The aim of this review is to consider the mechanisms that underlie UVA-induced cellular damage, how this damage may be prevented or repaired and the signal transduction processes that are elicited in response to it.

RESULTS

Exposure to ultraviolet (UV) light is well-established as the causative factor in skin cancer. Until recently, most work on the mechanisms that underlie skin carcinogenesis focused on shorter wavelength UVB radiation (280-315 nm), however in recent years there has been increased interest in the contribution made by UVA. UVA is able to cause a range of damage to cellular biomolecules including lipid peroxidation, oxidized protein and DNA damage, such as 8-oxoguanine and cyclobutane pyrimidine dimers. Such damage is strongly implicated in both cell death and malignant transformation and cells have a number of mechanisms in place to mitigate the effects of UVA exposure, including antioxidants, DNA repair, and stress signalling pathways.

CONCLUSIONS

The past decade has seen a surge of interest in the biological effects of UVA exposure as its significance to the process of photo-carcinogenesis has become increasingly evident. However, unpicking the unique complexity of the cellular response to UVA, which is only now becoming apparent, will be a major challenge for the field of photobiology in the 21st century.

Extracutaneous malignant melanomas

Extracutaneous malignant melanomas are rare tumors with vexing clinical presentation and grim prognosis. Only 4%-5% of all primary melanomas do not arise from the skin. These tumors are almost uniformly fatal, even in 2006. Although a fairly good number of these lesions were reported in the literature, the lack of a side-by-side analysis of these studies has resulted in tentative conclusions that merely offer a first glimpse at the clinicopathologic diversity of these lesions. To remedy this issue, this article took an aim at presenting a literature review concerning extracutaneous malignant melanomas. It also reports several cases of extracutaneous melanomas, which I came across in my 15 years of surgical and molecular pathology practice. The study raises several notions. Extracutaneous malignant melanomas are rare but extremely aggressive lesions with a grim outcome. They include ocular, metastatic, anorectal, mucosal, nail beds, conjunctival, vaginal, urogenital, orbital, esophageal, and leptomeningial malignant melanomas. The development of these lesions lacks an association with sun damage, family history, or precursor nevi. These lesions cause considerable diagnostic consternation and their distinction from other types of tumors (such as undifferentiated carcinomas, high-grade sarcomas, and lymphomas) is critical both from a diagnostic and prognostic point of view. In the proper clinical, histological, and cytological context, immunopositivity for S100 protein, HMB45, and vimentin allows the distinction of these malignant melanomas from other histologically similar malignancies. To conclude, extracutaneous melanoma should be considered while undifferentiated neoplasms, especially those displaying prominent eosinophilic nucleoli, and the coexistence of epithelioid and spindle cells. Special staining and immunohistochemistry should be resorted to establish the diagnosis.

Melanosomal damage in normal human melanocytes induced by UVB and metal uptake--a basis for the pro-oxidant state of melanoma

Melanins are ubiquitous catecholic pigments, formed in organelles called melanosomes within melanocytes, the function of which is to protect skin against harmful effects of UV radiation. Melanosomes within melanoma cells are characteristically abnormal, with fragmented melanin and disrupted membranes. We hypothesize that the disruption of melanosomal melanin might be an early event in the etiology and progression of melanoma, leading to increased oxidative stress and mutation. In this report, we examine the effect of a combination of UV treatment and metal ion exposure on melanosomes within melanocytes, as well as their ability to act as pro-oxidants in ex situ experiments, and assay the effects of this treatment on viability and cell cycle progression. UVB exposure causes morphologic changes of the cells and bleaching of melanosomes in normal melanocytes, both significantly enhanced in Cu(II) and Cd(II)-treated cells, as observed by microscopy. The promoted bleaching by Cu(II) is due to its ability to redox cycle under oxidative conditions, generating reactive oxygen species; verified by the observed enhancement of hydroxyl radical generation when isolated melanosomes were treated with both Cu(II) ions and UVB, as assayed by DNA clipping. Single-dose UVB/Cu treatment does not greatly affect cell viability or cell cycle progression in heavily pigmented cells, but did so in an amelanotic early stage melanoma cell line.

Downregulation of cell cycle modulators p21, p27, p53, Rb and proapoptotic Bcl-2-related proteins Bax and Bak in cutaneous melanoma is associated with worse patient prognosis: preliminary findings

BACKGROUND

Cutaneous melanoma is a tumor with high metastatic potential, but the mechanisms leading to progression are still not fully understood. To provide further molecular basis for understanding the progression of melanoma, the aim of this study was to examine the expression pattern of cell cycle modulators (p21, p27, p53 and Rb) and proapoptotic multidomain Bcl-2 related proteins (Bax and Bak) and to analyze its differences in patients with and without progression stages.

METHODS

We have studied 31 patients with cutaneous melanoma at stage IIa (Breslow thickness 1.5-4.0 mm), and follow them for 10-year period. Eighteen of these patients developed metastasis. The determination of selected molecular markers participating in cell cycle regulation and apoptosis was performed by immunohistochemistry.

RESULTS

We have observed a significant increase in the loss of expression of the Bax, Bak, p21, p27, p53 and Rb. The analysis of the relationship between these downregulated markers and Breslow thickness showed significant positive correlation (r=0.556, p=0.029) and predictive value if thickness below 2.3 mm (OR=3.0, 95% CI=0.312-28.84).

CONCLUSIONS

Our study showed that the downregulation of the markers associated with cell cycle control and apoptosis is of great value in predicting malignant transformation and in assessing the risk of metastases development for 10-year follow-up period.

Development and characteristics of a human cell assay for screening agents for melanoma prevention

This paper describes the development and initial evaluation of a human cell assay to identify potentially efficacious agents for preventing melanoma. Four human cell lines were used: normal melanocytes, a radial growth-phase-like melanoma cell line (WM3211), a vertical growth-phase-like melanoma cell line (Lu1205), and 83-2c, a cell strain cloned from metastatic melanoma. Four endpoints were evaluated in ultraviolet B-treated cells: annexin V, human leukocyte antigen-DR; E-cadherin, and N-cadherin. Annexin V was induced by nimesulide, 4-hydroxyphenylretinamide, and difluoromethylornithine in ultraviolet-B-treated radial growth-phase-like melanoma cells. None of the agents inhibited human leukocyte antigen-DR expression in ultraviolet-B-treated radial growth-phase-like melanoma cells, the only cells that strongly expressed human leukocyte antigen-DR. E-cadherin was overexpressed only in radial growth-phase-like melanoma cells relative to melanocytes, and ultraviolet B exposure dramatically reduced this expression. E-cadherin was only induced by difluoromethylornithine in ultraviolet-B-treated radial growth-phase-like melanoma cells. N-cadherin was over- expressed in all melanoma cell lines relative to melanocytes. In this study, all candidate preventive agents inhibited N-cadherin in ultraviolet B-treated radial growth-phase-like melanoma cells. Four agents inhibited N-cadherin in ultraviolet B-treated vertical growth-phase-like melanoma cells. The mean ratios of N-cadherin to E-cadherin levels and specific endpoint responses for both the radial growth-phase-like melanoma and vertical growth-phase-like melanoma cells were used to rank the agents. Agents were evaluated at clinically relevant concentrations. The rankings were difluoromethylornithine>4-hydroxyphenylretinamide>nimesulide>9-cis-retinoic acid>polyphenon E. Diphenylhydramine, D-mannitol, and nordihydroguaiaretic acid were inactive. The results of these initial studies suggest that ultraviolet-B-treated radial growth-phase-like melanoma cells are the most responsive to chemopreventive agents, and may be the cell line of choice for screening melanoma prevention agents.

Variation in Incidence and Fatality of Melanoma by Season of Diagnosis in New South Wales, Australia

Seasonal variation in cutaneous melanoma incidence with a summer peak is poorly understood. It has been hypothesized to be due to increased diagnosis in summer or a late-promoting effect of sun exposure. We analyzed the characteristics of incident cases of cutaneous melanoma and their outcome by season of diagnosis in the population of New South Wales, Australia. Cases of melanoma (25,845 cases; 10,869 females and 14,976 males) were registered by the New South Wales Central Cancer Registry in 1989 to 1998. There was significant seasonal variation in incidence (P < 0.0001, Nam test). The summer to winter ratio was greater for women, younger people, lesions on the limbs, and superficial spreading melanoma. Melanomas were thicker in winter than in summer (medians 0.75 and 0.70 mm, respectively; P < 0.0001, Kruskal-Wallis test). Cases were followed for a median of 63 months and 2,710 (10.5%) died from their melanoma. Fatality from melanoma was lower for melanomas diagnosed in summer than winter (relative fatality = 0.72; 95% confidence interval, 0.65-0.81); the 5-year survival rate was 92.1% for diagnosis in summer and 89.0% for diagnosis in winter. This result remained significant after adjustment for year of diagnosis, age, sex, Breslow thickness, anatomic location, and histologic type (relative fatality = 0.82; 95% confidence interval, 0.72-0.94). Seasonality in melanoma incidence is probably caused mainly by increased and earlier diagnosis in summer, although a late-stage promotional effect of sun exposure cannot be excluded completely. Earlier diagnosis may also reduce fatality when melanoma is diagnosed in summer. Independence of variation in fatality with season from seasonal variation in thickness, however, suggests that sun exposure around the time of diagnosis decreases fatality of melanoma.