Reduction in squamous cell carcinomas in mouse skin by dietary zinc supplementation

Influence of environmental risk factors on the development of wounds associated with squamous cell carcinoma

The incidence of squamous cell carcinoma (SCC) is on the rise, making it a significant global health concern. Environmental risk factors are crucial to the development of SCC. This study sought to examine comprehensively the impact of these factors on the onset of SCC. We conducted a cross-sectional study involving 480 participants at Beijing tertiary care hospital. Utilizing structured questionnaires, data on demographics, environmental exposures, medical history and clinical characteristics were collected. The cohort was composed of 272 men (56.67%) and 208 women (43.33%). The majority (44.38%) were between ages of 41 and 60, and Type III skin predominated (34.79%). Most of the participants belonged to the middle socioeconomic class (60.83%). 'Vegetarian' dietary habits (46.67%) were prevalent, as was the 'Sedentary' lifestyle (49.79%). Regarding environmental exposures, moderate sun exposure of 3 to 5 h per day (54.58%) and UV protective eyewear (30.83%) were prevalent. The majority (69.58%) of respondents indicated 'Never' exposure to carcinogens. A variety of wound characteristics were observed, with 'non-smokers' (64.17%) dominating. Most SCC lesions were located on the extremities (40.21%), lasted less than 6 months (44.38%) and measured 1-3 cm (39.79%). The majority (54.58%) did not have a history of cutaneous injuries. Our research uncovered substantial relationships between SCC and numerous environmental variables, gender, Fitzpatrick skin type, occupation, duration of sun exposure, exposure to carcinogens, dietary practices, history of skin wounds, wound location, duration, size and depth were significantly associated with the onset of SCC. These results highlighted the complexity of SCC aetiology and need for individualized prevention and treatment strategies.

Zinc treatment reverses and anti-Zn-regulated miRs suppress esophageal carcinomas in vivo

Esophageal squamous cell carcinoma (ESCC) is a deadly disease with few prevention or treatment options. ESCC development in humans and rodents is associated with Zn deficiency (ZD), inflammation, and overexpression of oncogenic microRNAs: miR-31 and miR-21. In a ZD-promoted ESCC rat model with upregulation of these miRs, systemic antimiR-31 suppresses the miR-31-EGLN3/STK40-NF-κB-controlled inflammatory pathway and ESCC. In this model, systemic delivery of Zn-regulated antimiR-31, followed by antimiR-21, restored expression of tumor-suppressor proteins targeted by these specific miRs: STK40/EGLN3 (miR-31), PDCD4 (miR-21), suppressing inflammation, promoting apoptosis, and inhibiting ESCC development. Moreover, ESCC-bearing Zn-deficient (ZD) rats receiving Zn medication showed a 47% decrease in ESCC incidence vs. Zn-untreated controls. Zn treatment eliminated ESCCs by affecting a spectrum of biological processes that included downregulation of expression of the two miRs and miR-31-controlled inflammatory pathway, stimulation of miR-21-PDCD4 axis apoptosis, and reversal of the ESCC metabolome: with decrease in putrescine, increase in glucose, accompanied by downregulation of metabolite enzymes ODC and HK2. Thus, Zn treatment or miR-31/21 silencing are effective therapeutic strategies for ESCC in this rodent model and should be examined in the human counterpart exhibiting the same biological processes.

Protective effects of andrographolide sodium bisulfate on UV-induced skin carcinogenesis in mice model

Although the mortality of skin cancer patients is relatively low, there are still a large number of patients died of these tumors at high incidence rate. Chronic exposure to solar UV irradiation is the most common cause of nonmelanoma skin tumors. Our research aimed to explore the effects of andrographolide sodium bisulfate (ASB) on UV-induced skin cancer and to reveal the underlying molecular mechanism. In the present study, histopathology changes, immunohistochemical analysis, ELISA analysis and western blot analysis were mainly used in vivo. The results indicated that ASB significantly inhibited increase of skin epidermal thickness, inflammatory cells infiltration and fibers damage in dermis, oxidative stress injury and skin carcinogenesis. Moreover, the western blot analysis showed that protein expressions of NF-κB, Nrf2, p62, LC3 II/I and p-p62 (Ser 349) in mouse skin induced by UV were dramatically suppressed in the ASB-pretreated groups. Overall, these results suggested that ASB exerted a strong preventive effect and potential therapeutic value against UV-induced skin carcinogenesis in mice through inhibiting NF-κB and Nrf2 signaling pathways and restoring autophagy.

Zinc, ω-3 polyunsaturated fatty acids and vitamin D: An essential combination for prevention and treatment of cancers

Zinc, ω-3 polyunsaturated fatty acids (PUFAs) and vitamin D are essential nutrients for health, maturation and general wellbeing. Extensive literature searches have revealed the widespread similarity in molecular biological properties of zinc, ω-3 PUFAs and vitamin D, and their similar anti-cancer properties, even though they have different modes of action. These three nutrients are separately essential for good health, especially in the aged. Zinc, ω-3 PUFAs and vitamin D are inexpensive and safe as they are fundamentally natural and have the properties of correcting and inhibiting undesirable actions without disturbing the normal functions of cells or their extracellular environment. This review of the anticancer properties of zinc, ω-3 PUFAs and vitamin D is made in the context of the hallmarks of cancer. The anticancer properties of zinc, ω-3 PUFAs and vitamin D can therefore be used beneficially through combined treatment or supplementation. It is proposed that sufficiency of zinc, ω-3 PUFAs and vitamin D is a necessary requirement during chemotherapy treatment and that clinical trials can have questionable integrity if this sufficiency is not checked and maintained during efficacy trials.

Serum Levels of Zinc, Copper and Ferritin in Patients with Salivary Gland Tumors

Background: Variation in serum levels of trace elements including zinc, copper and ferritin has been reported in cancer patients. The aim of this study was to evaluate these trace elements in the patients’ sera with benign and malignant salivary gland tumors (SGTs) and compare them with normal individuals. Methods: In this cross-sectional study, 60 patients with SGTs including 16 pleomorphic adenoma and 44 malignant SGTs, as well as 28 healthy controls, were enrolled. Serum levels of zinc, copper and ferritin were determined by atomic absorption and ELISA methods. Data were analyzed using one way ANOVA, Chi-square, Kruskal-Wallis and Mann- Whitney tests. Results: The mean concentration of zinc, copper, ferritin was1.5± 2 ppm, 1.2± 0.5 ppm, and 96.7± 65.7 ng/ml in PA, 1.5± 1.4,1.3± 0.4, and 111.2± 112 in malignant SGTs, and1.1±0.3, 1.2± 0.23 and 124±135.8 in normal control groups. There was no statistically significant difference between the patients and control groups, and between benign and malignant SGTs (P>0.05). Conclusion: The serum levels of trace elements in SGTs were not different from normal individuals. The results might have been affected by some interventional factors. Therefore, designing cohort complementary studies might result in obtaining more accurate data.

The effect of zinc and melatonin supplementation on immunity parameters in breast cancer induced by DMBA in rats

OBJECTIVE

The aim of the study was to determine the effects of zinc and melatonin supplements on the immunity parameters of female rats with breast cancer induced by DMBA.

METHODS

Group 1; Control, Group 2; 7,12-dimethylbenz[a]anthracene (DMBA), Group 3; DMBA + zinc, Group 4; DMBA + melatonin, Group 5; DMBA + zinc + melatonin. The rats' breast cancer was induced by DMBA 80 mg/kg. Groups 3-5 received daily 5 mg/kg doses of zinc, melatonin, and zinc + melatonin, respectively. Lymphocyte rates, T-lymphocyte subgroups, B-lymphocyte and natural killer cells (NK), and natural killer T (NKT) were evaluated.

RESULTS

The most significant increase in lymphocyte, T-lymphocyte, and CD4 lymphocyte rates was found in Group 5. The highest NKT cell rates were found in Group 3.

CONCLUSIONS

Findings show that zinc and melatonin supplements have led to an increase in the immunity parameters of rats with breast cancer.

A Topical Zinc Ionophore Blocks Tumorigenic Progression in UV-exposed SKH-1 High-risk Mouse Skin

Nonmelanoma skin cancer (NMSC) is the most common malignancy in the United States representing a considerable public health burden. Pharmacological suppression of skin photocarcinogenesis has shown promise in preclinical and clinical studies, but more efficacious photochemopreventive agents are needed. Here, we tested feasibility of harnessing pharmacological disruption of intracellular zinc homeostasis for photochemoprevention in vitro and in vivo. Employing the zinc ionophore and FDA-approved microbicidal agent zinc pyrithione (ZnPT), used worldwide in over-the-counter (OTC) topical consumer products, we first demonstrated feasibility of achieving ZnPT-based intracellular Zn²⁺ overload in cultured malignant keratinocytes (HaCaT-ras II-4; SCC-25) employing membrane-permeable fluorescent probes. Zinc overload was accompanied by induction of intracellular oxidative stress, associated with mitochondrial superoxide release as substantiated by MitoSOX Red™ fluorescence microscopy. ZnPT-induced cell death observable in malignant keratinocytes was preceded by induction of metal (MT2A), proteotoxic (HSPA6, HSPA1A, DDIT3, HMOX1) and genotoxic stress response (GADD45A, XRCC2) gene expression at the mRNA and protein levels. Comet analysis revealed introduction of formamidopyrimidine-DNA glycosylase (Fpg)-sensitive oxidative DNA lesions. In a photocarcinogenesis model (UV-exposed SKH-1 high-risk mouse skin), topical ZnPT administration post-UV caused epidermal zinc overload and stress response gene expression with pronounced blockade of tumorigenesis. Taken together, these data suggest feasibility of repurposing a topical OTC drug for zinc-directed photochemoprevention of solar UV-induced NMSC.

Surface-tailored nanomixed micelles containing quercetin–salicylic acid physical complex for enhanced cellular and in vivo activities: a quality by design perspective

Aim: The development of surface-tailored quercetin (QCT)–salicylic acid (SA) physical complex for effective treatment of skin carcinoma. Materials & methods: QCT–SA nanomixed micelles were prepared by the self-assembly method employing the Quality by Design (QbD) approach and evaluated for various in vitro, ex vivo and in vivo parameters. Results: The optimized formulation showed enhanced percent permeation (Q24), in other words, 78.12 ± 0.47, improved in vitro cellular uptake and annexin-V–apoptosis assay exhibited 60.86% cell death. The 7,12-dimethylbenz(a)anthracene and histopathology protocol revealed the improved antineoplastic action of QCT. The dermatokinetic profile showed the maximum drug concentration (6 h), in other words, 416.02 ± 26 μg/cm2 in epidermis and 103.65 ± 12 μg/cm2 in dermis. Conclusion: The overall performance ratified the safety and efficacy of optimized nanomixed micelless of QCT with SA in a synergistic manner.

Reduction in squamous cell carcinomas in mouse skin by dietary zinc supplementation

Inadequate dietary Zn consumption increases susceptibility to esophageal and other cancers in humans and model organisms. Since Zn supplementation can prevent cancers in rodent squamous cell carcinoma (SCC) models, we were interested in determining if it could have a preventive effect in a rodent skin cancer model, as a preclinical basis for considering a role for Zn in prevention of human nonmelanoma skin cancers, the most frequent cancers in humans. We used the 7,12-dimethyl benzanthracene carcinogen/phorbol myristate acetate tumor promoter treatment method to induce skin tumors in Zn-sufficient wild-type and Fhit (human or mouse protein) knockout mice. Fhit protein expression is lost in >50% of human cancers, including skin SCCs, and Fhit-deficient mice show increased sensitivity to carcinogen induction of tumors. We hypothesized that: (1) the skin cancer burdens would be reduced by Zn supplementation; (2) Fhit(-/-) (Fhit, murine fragile histidine triad gene) mice would show increased susceptibility to skin tumor induction versus wild-type mice. 30 weeks after initiating treatment, the tumor burden was increased ~2-fold in Fhit(-/-) versus wild-type mice (16.2 versus 7.6 tumors, P < 0.001); Zn supplementation significantly reduced tumor burdens in Fhit(-/-) mice (males and females combined, 16.2 unsupplemented versus 10.3 supplemented, P = 0.001). Most importantly, the SCC burden was reduced after Zn supplementation in both strains and genders of mice, most significantly in the wild-type males (P = 0.035). Although the mechanism(s) of action of Zn supplementation in skin tumor prevention is not known in detail, the Zn-supplemented tumors showed evidence of reduced DNA damage and some cohorts showed reduced inflammation scores. The results suggest that mild Zn supplementation should be tested for prevention of skin cancer in high-risk human cohorts.