Mutant p53 reactivator SLMP53-2 hinders ultraviolet B radiation-induced skin carcinogenesis.

The growing incidence of skin cancer (SC) has prompted the search for additional preventive strategies to counteract this global health concern. Mutant p53 (mutp53), particularly with ultraviolet radiation (UVR) signature, has emerged as a promising target for SC prevention based on its key role in skin carcinogenesis. Herein, the preventive activity of our previously disclosed mutp53 reactivator SLMP53-2 against UVR-induced SC was investigated. The pre-treatment of keratinocyte HaCaT cells with SLMP53-2, before UVB exposure, depleted mutp53 protein levels with restoration of wild-type-like p53 DNA-binding ability and subsequent transcriptional activity. SLMP53-2 increased cell survival by promoting G1-phase cell cycle arrest, while reducing UVB-induced apoptosis through inhibition of c-Jun N-terminal kinase (JNK) activity. SLMP53-2 also protected cells from reactive oxygen species and oxidative damage induced by UVB. Moreover, it enhanced DNA repair through upregulation of nucleotide excision repair pathway and depletion of UVB-induced DNA damage, as evidenced by a reduction of DNA in comet tails, γH2AX staining and cyclobutane pyrimidine dimers (CPD) levels. SLMP53-2 further suppressed UVB-induced inflammation by inhibiting the nuclear translocation and DNA-binding ability of NF-κB, and promoted the expression of key players involved in keratinocytes differentiation. Consistently, the topical application of SLMP53-2 in mice skin, prior to UVB irradiation, reduced cell death and DNA damage. It also decreased the expression of inflammatory-related proteins and promoted cell differentiation, in UVB-exposed mice skin. Notably, SLMP53-2 did not show signs of skin toxicity for cumulative topical use. Overall, these results support a promising protective activity of SLMP53-2 against UVB-induced SC.

Comparison of skin cancer awareness and sun protection behaviours between renal transplant recipients and patients with glomerular disease treated with immunosuppressants.

BACKGROUND: There is no previous study that compare skin cancer awareness and photoprotective behaviours between renal transplant recipients (RTR) and patients with glomerular disease (GD). OBJECTIVES/METHODS: Sixty-one RTR and 51 patients with GD were given a self-reported questionnaire to evaluate skin cancer awareness and photoprotective behaviours in this cross-sectional study. The former group received a formal education on skin cancer and the latter an informal session prior to immunosuppressant use. RESULTS: Ninety-three percent (n = 57) of RTRs and 88% (n = 45) of patients with GD responded to the survey. Majority of participants from both groups were aware that ultraviolet radiation could play a role in the occurrence of skin cancers and the awareness increased in participants with higher education (odds ratio [OR] = 1.50, 95% confidence interval [CI] = 1.15-1.95, P = .003). Ninety-eight percent vs 71% were aware that immunosuppressants can increase the risk of developing cancer (P < .001) and higher awareness was noted in younger participants (OR = 0.92, 95% CI = 0.87-0.97, P = .003). Suboptimal photoprotective behaviours (sun avoidance, sunscreen usage and sun-protective clothing) were noted in both cohorts and slightly lower sun protection rates were reported in RTR when compared with patients having GD. The level of sun protective measures in RTR based on high, moderate and minimal use of photoprotective measures were 21%, 46% and 33%, respectively. In terms of patients with GD, the latter practices were 13%, 50% and 37%, respectively (P = .560). Higher educational status was significantly associated with better sunscreen usage in RTR (P = .017) whereas this finding was not observed in patients with GD. CONCLUSION: Patients with GD and RTR should have formal education on the risks of skin cancers before starting immunosuppressants. Follow-up education and surveillance is required to improve skin protective practices in these patients.

Ultraviolet light and melanoma.

Melanoma is a clinically heterogeneous disease, and current strategies for treatment of the primary tumour are based on pathological criteria alone. In the recent past, several DNA-sequencing and RNA-sequencing studies of primary and advanced melanoma samples have identified unique relationships between somatic mutations, genomic aberrations, and the genetic fingerprint of ultraviolet radiation (UVR). The recurrent patterns of genomic alterations reveal different disease pathways, drug targets and mechanisms limiting drug response. Here, we examine the known associations between the molecular categories of melanoma and the multidimensional UVR damage. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Sunbed Use Increases Cutaneous Squamous Cell Carcinoma Risk in Women: A Large-scale, Prospective Study in Sweden.

The incidence of cutaneous squamous cell carcinoma has increased rapidly in Sweden in the past decades. Here, we present a prospective study of the Melanoma in Southern Sweden (MISS)-cohort, with 29,460 participating women in southern Sweden that investigates the risk factors for cutaneous squamous cell carcinoma. Data on the host and skin cancer risk factors were collected through questionnaires and then matched with the National Cancer Registry. Statistical analyses were based on uni- and multivariable Cox proportional hazards models, using age as the time-scale. We found that sunbed use (hazard ratio (HR) 1.2, 95% CI: 1.1-1.4), red and light blond hair (HR 1.6, 95% CI: 1.1-2.3), freckles (HR 1.4, 95% CI: 1.1-1.8) and immunosuppressive medications (HR 2.1, 95% CI: 1.3-4.5) were independent risk factors. Furthermore, we observed a dose-dependent relationship between sunbed use and the development of cutaneous squamous cell carcinoma. Our findings support the idea of integrating dermatological follow-up examinations for immunosuppressed patients and banning the use of sunbeds in order to prevent cutaneous squamous cell carcinoma.

Radiation-induced inflammatory cascade and its reverberating crosstalks as potential cause of post-radiotherapy second malignancies.

The disease-free survival following radiotherapy is often limited by the development of second/secondary cancers. This significant impediment to effective cancer treatment implicated even in the modern-day radiotherapy needs to be countered effectively. Critical analysis reveals that besides achieving effective tumor control, radiotherapy elicits certain cellular and systemic inflammatory events in tumor infiltrate, which remain relatively stable and tend to facilitate "in-field" or "out of field" oncogenesis in due course of time. Acute pro-inflammatory cytokines generated as a result of radiation-induced oxidative insult and DNA damage induce genetic instability that contributes to tumor heterogeneity and plasticity. The reverberating crosstalks between radiation-targeted tumor and its microenvironment in turn initiate inflammatory loops that feedback the immune system to manifest as systemic consequences. An "inflammatory switchover" within the tumor microenvironment is thus induced by cumulative radiation exposure, initiating pro-tumor events that can severely limit the outcome of radiotherapy. Various pro-survival tumorigenic pathways activated as a result regulate radiation-induced hypoxia, ECM remodeling, angiogenesis/vasculogenesis, and immune suppression/evasion within the tumor microenvironment. NF-κB, HIF and STAT are identified as central regulating mediators among others that orchestrate inflammatory switchover from apoptosis-mediated tumor surveillance to radiation-induced carcinogenesis. Radiation-induced interleukins stimulate recruited macrophages and endothelial cells to promote intravasation, which is further aided by release of chemokines favoring extravasation and secondary site lesions. We hence propose that delineating the inflammatory signaling network emanating from irradiation of complex tumor tissue is critical for devising suitable therapeutic strategies to prevent post-radiotherapy second cancers or metastasis. Graphical Abstract ᅟ.

Ultraviolet Radiations: Skin Defense-Damage Mechanism.

UV-radiations are the invisible part of light spectra having a wavelength between visible rays and X-rays. Based on wavelength, UV rays are subdivided into UV-A (320-400 nm), UV-B (280-320 nm) and UV-C (200-280 nm). Ultraviolet rays can have both harmful and beneficial effects. UV-C has the property of ionization thus acting as a strong mutagen, which can cause immune-mediated disease and cancer in adverse cases. Numbers of genetic factors have been identified in human involved in inducing skin cancer from UV-radiations. Certain heredity diseases have been found susceptible to UV-induced skin cancer. UV radiations activate the cutaneous immune system, which led to an inflammatory response by different mechanisms. The first line of defense mechanism against UV radiation is melanin (an epidermal pigment), and UV absorbing pigment of skin, which dissipate UV radiation as heat. Cell surface death receptor (e.g. Fas) of keratinocytes responds to UV-induced injury and elicits apoptosis to avoid malignant transformation. In addition to the formation of photo-dimers in the genome, UV also can induce mutation by generating ROS and nucleotides are highly susceptible to these free radical injuries. Melanocortin 1 receptor (MC1R) has been known to be implicated in different UV-induced damages such as pigmentation, adaptive tanning, and skin cancer. UV-B induces the formation of pre-vitamin D3 in the epidermal layer of skin. UV-induced tans act as a photoprotection by providing a sun protection factor (SPF) of 3-4 and epidermal hyperplasia. There is a need to prevent the harmful effects and harness the useful effects of UV radiations.

Cancer incidence vs. FM radio transmitter density.

BACKGROUND: In 2002, a strong association was highlighted between local melanoma incidence and the number of locally covering main Frequency Modulation (FM) transmitters in Sweden. This study investigated whether an association also exists between melanoma incidence and the average density of main FM transmitters in different European countries. METHODS: Twenty-three different European countries were asked to disclose the number of main transmitters used for the FM broadcasting band (87·5-108 MHz) in the respective country. Incidences of melanoma, breast cancer and all cancers together per country were correlated with their respective average density of transmitters per 10,000 km(2). FINDINGS: Both melanoma and breast cancer, as well as all cancers together, appear to be significantly associated with the density of main FM broadcasting transmitters in the European countries examined. INTERPRETATION: The findings present strong support to the earlier presented hypothesis that body-resonant broadcasting radiation emitted by horizontally polarized main FM transmitters has an immune-disturbing effect. FUNDING: This study was financed by internal funds within Hallberg Independent Research only.

Blackberry extract inhibits UVB-induced oxidative damage and inflammation through MAP kinases and NF-κB signaling pathways in SKH-1 mice skin.

Extensive exposure of solar ultraviolet-B (UVB) radiation to skin induces oxidative stress and inflammation that play a crucial role in the induction of skin cancer. Photochemoprevention with natural products represents a simple but very effective strategy for the management of cutaneous neoplasia. In this study, we investigated whether blackberry extract (BBE) reduces chronic inflammatory responses induced by UVB irradiation in SKH-1 hairless mice skin. Mice were exposed to UVB radiation (100 mJ/cm(2)) on alternate days for 10 weeks, and BBE (10% and 20%) was applied topically a day before UVB exposure. Our results show that BBE suppressed UVB-induced hyperplasia and reduced infiltration of inflammatory cells in the SKH-1 hairless mice skin. BBE treatment reduced glutathione (GSH) depletion, lipid peroxidation (LPO), and myeloperoxidase (MPO) in mouse skin by chronic UVB exposure. BBE significantly decreased the level of pro-inflammatory cytokines IL-6 and TNF-α in UVB-exposed skin. Likewise, UVB-induced inflammatory responses were diminished by BBE as observed by a remarkable reduction in the levels of phosphorylated MAP Kinases, Erk1/2, p38, JNK1/2 and MKK4. Furthermore, BBE also reduced inflammatory mediators such as cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), and inducible nitric oxide synthase (iNOS) levels in UVB-exposed skin. Treatment with BBE inhibited UVB-induced nuclear translocation of NF-κB and degradation of IκBα in mouse skin. Immunohistochemistry analysis revealed that topical application of BBE inhibited the expression of 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxodG), cyclobutane pyrimidine dimers (CPD), proliferating cell nuclear antigen (PCNA), and cyclin D1 in UVB-exposed skin. Collectively, these data indicate that BBE protects from UVB-induced oxidative damage and inflammation by modulating MAP kinase and NF-κB signaling pathways.

Nutritional abrogation of photoimmunosuppression: in vivo investigations.

Skin cancer is a major public health concern, and the primary aetiological factor in the majority of skin cancers is ultraviolet radiation (UVR) exposure. UVR not only induces potentially mutagenic DNA damage but also suppresses cell-mediated immunity (CMI), allowing cancerous cells to escape destruction and progress to tumours. A considerable proportion of an individual's annual sun exposure is obtained outside the vacation period when topical and physical measures for photoprotection are irregularly used. Certain nutrients could provide an adjunctive protective role, and evidence is accruing from experimental studies to support their use in abrogation of photoimmunosuppression. Moreover, developments in clinical research methods to evaluate impact of solar-simulated radiation on cutaneous CMI allow the immune protective potential of nutritional agents to be examined in humans in vivo. This article summarises the mediation of CMI and its suppression by UVR, evaluates the methodology for quantitative assessment in vivo, reviews the human studies reported on nutritional abrogation of photoimmunosuppression including recent randomized controlled trials and discusses the mechanisms of photoprotection by the nutrients. This includes, in addition to antioxidants, novel studies of omega-3 polyunsaturated fatty acids and nicotinamide.

Sunscreens in the United States: current status and future outlook.

Incidence rates of nonmelanoma skin cancer and melanoma has been on the rise in the United States for the past 20 years. UV radiation (UVR) exposure remains the most preventable environmental risk factor for these cancers. Aside from sun avoidance, sunscreens remain our best protection. UVR directly damages DNA and cause indirect cellular damage through the creation of reactive oxygen species, the sum of which leads to cutaneous immunosuppression and a tumorigenic milieu. The current generation of sunscreens protect from UVR through two main mechanisms: absorption and deflection. In the US, new Food and Drug Association rules require sunscreen manufacturers to evaluate their products not only on sun protection factor but also on broad spectrum UVA protection by the end of 2013. New labeling requirements will also be instituted. The American Academy of Dermatology and the American Academy of Pediatrics have provided specific recommendations for proper sun protection and sunscreen usage. Plant polyphenols such as those isolated from green tea, pomegranate, and grape seed remain an interesting avenue of research as additives to sunscreens or stand-alone products that appear to modulate the immunosuppressive effects of UVR on the skin. Additionally, although UVR induces endogenous cutaneous production of vitamin D, its damaging effects overshadow this positive benefit, especially in light of the ease of achieving recommended amounts of vitamin D through diet and supplementation.

The etiology of treatment-related lymphopenia in patients with malignant gliomas: modeling radiation dose to circulating lymphocytes explains clinical observations and suggests methods of modifying the impact of radiation on immune cells.

PURPOSE: Severe treatment-related lymphopenia (TRL) occurs in 40% of patients with high grade gliomas (HGG) receiving glucocorticoids, temozolomide, and radiation. This occurs following radiation, persists for months, and is associated with reduced survival. As all three treatment modalities are lymphotoxic, this study was conducted to estimate the radiation dose that lymphocytes receive passing through the radiation field and if this could explain the observed TRL. MATERIALS AND METHODS: A typical glioblastoma plan (8-cm tumor, 60 Gy/30 fractions) was constructed using the Pinnacle™ radiation planning system. Radiation doses to circulating cells (DCC) were analyzed using MatLab™. The primary endpoints were mean DCC and percent of circulating cells receiving ≥0.5 Gy. The model was also used to study how changes in target volumes (PTV), dose rates, and delivery techniques affect DCC. RESULTS: The modeling determined that while a single radiation fraction delivered 0.5 Gy to 5% of circulating cells, after 30 fractions 99% of circulating blood had received ≥0.5 Gy. The mean DCC was 2.2 Gy and was similar for IMRT, 3D-conformal techniques, and different dose rates. Major changes in PTV size affected mean DCC and percent of circulating cells receiving ≥0.5 Gy. CONCLUSIONS: Standard treatment plans for brain tumors deliver potentially lymphotoxic radiation doses to the entire circulating blood pool. Altering dose rates or delivery techniques are unlikely to significantly affect DCC by the end of treatment. Novel approaches are needed to limit radiation to circulating lymphocytes given the association of lymphopenia with poorer survival in patients with HGG.

Therapeutic and immune effects of 5-aminolevulinic acid photodynamic therapy on UVB-induced squamous cell carcinomas in hairless mice.

The therapeutic effects of 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) on cutaneous squamous cell carcinoma (SCC) are not fully understood, and the usefulness of topical PDT in the treatment of SCC is still debatable. The most interesting aspect in SCC PDT is perhaps its potential in inducing antitumor immune responses. In this study, cutaneous SCCs were established by UVB irradiation of hairless mice and treated with multiple ALA PDT. Immunohistochemistry assays showed that ALA PDT could induce quick apoptosis, overexpression of TNFα and marked increases in DCs, CD4(+) and CD8(+) cells in tumor interstitium and subcutaneous connective tissues. However, a complete response was only achieved for small SCCs. The clinical value of ALA PDT-induced specific antitumor immune responses in long-term control of SCCs deserves further study.

Radiation-induced melanoma-associated leucoderma, systemic antimelanoma immunity and disease-free survival in a patient with advanced-stage melanoma: a case report and immunological analysis.

BACKGROUND: Melanoma is an immunogenic tumour. The development of skin depigmentation or melanoma-associated leucoderma (MAL) has been associated with favourable clinical outcome in patients with metastatic melanoma, especially after immunotherapy. Evidence for clinically meaningful enhancement of melanoma-directed autoimmunity, as indicated by MAL, after radiotherapy without immunotherapy has not yet been published. OBJECTIVES: We investigated whether a patient with stage IV melanoma, who developed leucoderma in the irradiated skin areas following radiotherapy and experienced exceptional disease-free survival of 3 years despite brain metastasis, possessed antimelanoma immunity that could be linked to the favourable disease course. METHODS: A detailed immunological analysis was performed consisting of immunohistochemistry of several melanoma tissues, and analyses of T cells isolated from the blood and MAL skin tissue for melanocyte/melanoma specificity and functionality, as well as the presence of a melanoma-specific antibody response. RESULTS: Immunological analyses showed the presence of CD8+ T cells and antibody responses directed against melanocyte differentiation antigens expressed in the primary tumour, lymph node and brain metastasis, indicating adequate tumour recognition by activated T cells. CONCLUSION: The immune responses found in this patient, probably enhanced by radiotherapy, are thought to have contributed to his favourable clinical course. Radiotherapy may act as local immunotherapy in patients with melanoma by destroying melanocytes, leading to the induction, or enhancement, of already existent antimelanoma immunity. As in patients treated with immunotherapy, this may lead to MAL, also at distant sites from the treated area. This patient is a clear example of the positive prognostic value of MAL, which is possibly induced by radiotherapy, for patients with melanoma.

Lipoteichoic acid from Lactobacillus rhamnosus GG as an oral photoprotective agent against UV-induced carcinogenesis.

Probiotics are live micro-organisms that when administered in adequate amounts confer a health benefit on the host. Cell surface molecules of these micro-organisms are being studied in relation to their ability to interact with the host. The cell wall of lactobacilli possesses lipoteichoic acids (LTA) which are molecules with immunomodulatory properties. UV radiation (UVR) has been proposed as the main cause of skin cancer because of its mutagenic and immunosuppressive effects. Photoprotection with some nutrition interventions including probiotics has recently been shown. The aim of the present study was to investigate whether the oral administration of purified LTA from Lactobacillus rhamnosus GG can modulate the immune-suppressive effect of UVR and skin tumour development in female Crl:SKH-1-hrBR mice. For this purpose, two irradiation models were studied: (1) a chronic irradiation scheme consisting of daily irradiations during twenty consecutive days and (2) a long-term irradiation schedule, irradiating the animals three times per week, during 34 weeks for tumour development. The results showed that T-cells in the inguinal lymph node of LTA-treated mice produced higher levels of (1) interferon-γ and (2) a number of total, helper and cytotoxic T-cells compared with non-treated mice. Moreover, a significant delay in tumour appearance was found in LTA-treated mice. An increased IgA⁺ cell number was found in the small intestine together with a higher number of activated dendritic cells in the mesenteric lymph nodes. The latter results might be indicative of a direct effect of LTA in the gut, affecting the cutaneous immune system and restoring homeostasis through the gut-skin axis.

Dermal mast cells affect the development of sunlight-induced skin tumours.

Ultraviolet (UV) radiation contained in sunlight is considered a major risk in the induction of skin cancer. While mast cells are best known for their role in allergic responses, they have also been shown to play a crucial role in suppressing the anti-tumour immune response following UV exposure. Evidence is now emerging that UV may also trigger mast cell release of cutaneous tissue remodelling and pro-angiogenic factors. In this review, we will focus on the cellular and molecular mechanisms by which UV recruits and then activates mast cells to initiate and promote skin cancer development.

Photoprotection in immunocompetent and immunocompromised people.

Ultraviolet radiation (UVR) exposure from the sun and artificial UV sources has been widely acknowledged as the major culprit for skin cancer and premature skin ageing. Skin cancers are among the most dangerous (cutaneous malignant melanoma) and the most numerous (basal cell carcinoma, actinic keratosis and invasive squamous cell carcinoma) of all neoplasms in the caucasian population worldwide. Skin cancers therefore have a significant impact on public health and healthcare costs, and will continue to do so. It is obvious that adequate photoprotection - seeking shade, wearing protective clothing and using sunscreens - is the key to reducing the harmful effects of UVR in both immunocompetent and immunocompromised people. This article provides background information on UVR, photoprotection (including the concept of topical sunscreen formulations), associated concerns regarding efficacy and safety, and behavioural and educational aspects of photoprotection and skin cancer prevention in immunocompetent and immunocompromised people. Certain persistent misconceptions and mistakes regarding photoprotection are also addressed.

Neonatal mice do not have increased sensitivity to induction of squamous cell carcinomas.

BACKGROUND: Squamous cell carcinoma (SCC) is linked with the lifelong cumulative effect of ultraviolet radiation (UVR). In contrast, epidemiological data have shown that sunburn in childhood is a stronger risk factor for cutaneous malignant melanoma than continuous UVR, indicating a higher carcinogenic sensitivity early in life. METHODS: We investigated how a high neonatal dose of UVR affects the development of SCC in mice irradiated later in life. We used simulated solar radiation (sun) and solarium radiation (solarium). Ninety-nine C3.Cg/TifBomTac-immunocompetent hairless mice received 0, 25 or 35 standard erythema doses (SED) UVR when they were 4 days old followed by 4 SED sun or 4 SED solarium three times/weekly from 9 weeks of age. RESULTS: Tumours developed faster in mice treated with 35 SED UVR + 4 SED sun compared with 4 SED sun, but no change was observed in the cumulative dose required to achieve tumours. Tumours also developed faster in mice treated with 35 SED UVR + 4 SED solarium compared with 4 SED solarium, and a difference was also observed in the cumulative dose required to achieve tumours. If the Skin Cancer Utrecht-Philadelphia-murine spectrum was used to weigh the delivered irradiance instead of the International Commission on Illumination erythema action spectrum, tumours developed after the same accumulated dose. CONCLUSION: In conclusion, this study does not indicate increased sensitivity to induction of SCC early in life.

Differential expression of immune-associated cancer regulatory genes in low- versus high-dose-rate irradiated AKR/J mice.

AKR/J mice carrying leukemia viral inserts develop thymic lymphoma. Recently, we demonstrated that the incidence of thymic lymphoma was decreased when these mice were raised in a low-dose-rate γ-irradiation facility. In contrast, mice irradiated at a high-dose rate developed severe thymic lymphoma and died much earlier. To understand the genetic changes occurred by low- versus high-dose-rate γ-irradiation whole genome microarray was performed. Both groups of mice demonstrated up-regulation of Ifng, Igbp1, and IL7 in their thymuses, however, mice exposed to high-dose-rate γ-irradiation exhibited marked down-regulation of Sp3, Il15, Traf6, IL2ra, Pik3r1, and Hells. In contrast, low-dose-rate irradiated mice demonstrated up-regulation of Il15 and Jag2. These gene expression profiles imply the impaired immune signaling pathways by high-dose-rate γ-irradiation while the facilitation of anti-tumor immune responses by low-dose-rate γ-irradiation. Therefore, our data delineate common and distinct immune-associated pathways downstream of low- versus high-dose-rate irradiation in the process of cancer progression in AKR/J mice.

Ultraviolet and ionizing radiation enhance the growth of BCCs and trichoblastomas in patched heterozygous knockout mice.

Basal cell carcinomas, the commonest human skin cancers, consistently have abnormalities of the hedgehog signaling pathway and often have PTCH gene mutations. We report here that Ptch+/- mice develop primordial follicular neoplasms resembling human trichoblastomas, and that exposure to ultraviolet radiation or ionizing radiation results in an increase in the number and size of these tumors and a shift in their histologic features so that they more closely resemble human basal cell carcinoma. The mouse basal cell carcinomas and trichoblastoma-like tumors resemble human basal cell carcinomas in their loss of normal hemidesmosomal components, presence of p53 mutations, frequent loss of the normal remaining Ptch allele, and activation of hedgehog target gene transcription. The Ptch mutant mice provide the first mouse model, to our knowledge, of ultraviolet and ionizing radiation-induced basal cell carcinoma-like tumors, and also demonstrate that Ptch inactivation and hedgehog target gene activation are essential for basal cell carcinoma tumorigenesis.

[The epidemiological analysis of monitoring of the immune status in liquidators of consequences of the Chernobyl accident for early identification of risk groups and diagnostics of oncological diseases. Report 2. Dependence of frequency and changes in the immune status on risk factors of radiation accident].

Malignant neoplasms (MN) have been found to develop most frequently in the liquidators of entry into the ChNPP zones in 1986 (43.75%), as well as among the liquidators who worked for long, one quarter of whom participated in liquidation of the consequences of failure (LCF) in 1986. Specific features of the immune status depending on the timing of participation in LCF and the year of entry into the ChN PP zone have been established. Changes in the immune system in the persons with a confirmed diagnosis of MN who took both a non-permanent and permanent part in liquidating the consequences of the ChNPP failure in 1986 had the same character of deviations and differed in the magnitudes of deviations of immunological parameters. Continuous participation in the period of extreme conditions and a greater exposure to the radiation factor led to the increased content of CD8(+)-T-cells, CD16(+)-lymphocytes and activated T-lymphocytes, as well as to the reduced index of immune regulation, decreased content ofCD3-16/56+(NK)-cells (%) and the total IgE and to a greater deficiency of B-lymphocytes. Distinctions in the groups of liquidators who participated in LCF in 1986 and 1987 have been revealed. The greatest deviations in the IS indicators were found in liquidators-87. A similar effect came to light in case of a continuance in the ChNPP zones in 1986 and 1987; however, the degree of deviation of the content of CD4(+)-T-lymphocytes (41), CD8(+)-T-lymphocytes (1) and the immune regulation index (41) were remarkably higher in liquidators-87. A continuous stay in the ChNPP zones in 1987 led to the deficiency of CD4(+)-T-lymphocytes, increased values of CD8(+)-T-lymphocytes, a decreased index of CD4+/CD8+, as well as to the change in the ratio between NK-T and NK cells, increased numbers of CD95+, HLA-DR+ and activated T-lymphocytes, and a lower level of the total IgE. Long-term participation in LCF didn't cause any enhanced expression of cellular activation markers in liquidators-86. Specific features of changes in IS depending on a dose of external gamma-irradiation have been established. Increase in the frequency of MN among liquidators, in relation to the number of examinees in each age group, with age has been revealed. Distinctions in the age dynamics of IS in liquidators in the presence and in the absence of MN manifested themselves in a stable level of values of CD3+, CD4+, CD8(+)-T-lymphocytes, immune regulation index, CD95+, serum IgA at the age between 40 and 70 years old with a subsequent reduction in indicators and increase in the content of CD8(+)-T-lymphocytes with age in the absence of MN; continuous increase of CD3-16/56(+)-NK-cells in the presence of MN and decrease in the values after 70 in the absence of MN. Also revealed in IS of the both age groups of liquidators over 70 with and without MN was the deficiency of the T-cell component (CD3+, CD4(+)-T-lymphocytes, CD4+/CD8+ index) and the increase in absolute values of CD8(+)-T-lymphocytes. The growing deficiency of CD4(+)-T-lymphocytes during monitoring against the background of ever rising values of CD8(+)-T-lymphocytes leading to the weakening of the immune regulation due to progressing disorders of the T-lymphocyte regulatory subpopulation distribution can serve an indicator for the adverse prognosis of the life expectancy in the presence of MN.