The role of zinc transporter proteins as predictive and prognostic biomarkers of hepatocellular cancer

SLC39A14 promotes the development of esophageal squamous cell carcinoma through PI3K/Akt/mTOR signaling pathway

OBJECTIVES

This study aims to investigate the expression of solute carrier family 39 member 14 (SLC39A14) in esophageal squamous cell carcinoma (ESCC) tissues and its prognosis, as well as the impact of SLC39A14 expression on the biological behavior of ESCC cells and associated mechanisms.

METHODS

Bioinformatics analysis was utilized to compare the differential expression of SLC39A14 mRNA between esophageal cancer tissues and adjacent non-cancerous tissues. Immunohistochemistry was employed to evaluate SLC39A14 protein expression in human ESCC tissues and normal esophageal tissues, followed by an analysis of its association with clinicopathological parameters in esophageal cancer patients. Through cell proliferation, migration, invasion, and Western blot assays, we deeply evaluated the specific effects of SLC39A14 gene knockdown (or overexpression) on ESCC cells and explored its potential biological functions in ESCC. Subsequently, we validated the role of SLC39A14 in ESCC in a xenograft model. Furthermore, LY294002 drug intervention was used to verify the regulatory effect of SLC39A14 on PI3K/Akt/mTOR signaling pathway.

RESULTS

Both mRNA and protein levels of SLC39A14 were significantly elevated in tumor tissues from ESCC patients compared to adjacent normal tissues. Notably, higher levels of SLC39A14 expression positively correlated with ESCC tumor size (p = 0.010) and clinical T stage (p = 0.025), while exhibiting a negative correlation with overall patient survival rates (p = 0.023). In vitro experiments demonstrated that knocking down SLC39A14 significantly inhibited cell proliferation, migration and invasion. In vivo study showed that SLC39A14 facilitated progression within murine models bearing ESCC tumors. Mechanistic analyses suggested that pro-carcinogenic effects exerted by SLC39A14 are mediated through activation of the PI3K/Akt/mTOR signaling pathway.

CONCLUSIONS

Our findings suggest that SLC39A14 may serve as a potential biomarker for ESCC due to its pro-oncogenic role during ESCC progression.

Novel ectopic expression of zona pellucida 3 glycoprotein in lung cancer promotes tumor growth

Zona pellucida 3 (ZP3) expression is classically found in the ZP-layer of the oocytes, lately shown in ovarian and prostate cancer. A successful ZP3 ovarian cancer immunotherapy in transgenic mice suggested its use as an attractive therapeutic target. The biological role of ZP3 in cancer growth and progression is still unknown. We found that ~88% of the analyzed adenocarcinoma, squamous and small cell lung carcinomas to express ZP3. Knockout of ZP3 in a ZP3-expressing lung adenocarcinoma cell line, significantly decreased cell viability, proliferation, and migration rates in vitro. Zona pellucida 3 knock out (ZP3-KO) cell tumors inoculated in vivo in immunodeficient non-obese diabetic, severe combined immunodeficient mice showed significant inhibition of tumor growth and mitigation of the malignant phenotype. RNA sequencing revealed the deregulation of cell migration/adhesion signaling pathways in ZP3-KO cells. This novel functional relevance of ZP3 in lung cancer emphasized the suitability of ZP3 as a target in cancer immunotherapy and as a potential cancer biomarker.

Zinc and Diabetes: A Connection between Micronutrient and Metabolism

Diabetes mellitus is a global health problem and a major contributor to mortality and morbidity. The management of this condition typically involves using oral antidiabetic medication, insulin, and appropriate dietary modifications, with a focus on macronutrient intake. However, several human studies have indicated that a deficiency in micronutrients, such as zinc, can be associated with insulin resistance as well as greater glucose intolerance. Zinc serves as a chemical messenger, acts as a cofactor to increase enzyme activity, and is involved in insulin formation, release, and storage. These diverse functions make zinc an important trace element for the regulation of blood glucose levels. Adequate zinc levels have also been shown to reduce the risk of developing diabetic complications. This review article explains the role of zinc in glucose metabolism and the effects of its inadequacy on the development, progression, and complications of diabetes mellitus. Furthermore, it describes the impact of zinc supplementation on preventing diabetes mellitus. The available information suggests that zinc has beneficial effects on the management of diabetic patients. Although additional large-scale randomized clinical trials are needed to establish zinc's clinical utility further, efforts should be made to increase awareness of its potential benefits on human health and disease.

Marginal Maternal Zinc Deficiency Produces Liver Damage and Altered Zinc Transporter Expression in Offspring Male Rats

The aim of this study was to investigate how zinc deficiency and supplementation affect liver markers including autotaxin, kallistatin, endocan, and zinc carrier proteins ZIP14 and ZnT9 in rats exposed to maternal zinc deficiency. Additionally, the study aimed to assess liver tissue damage through histological examination. A total of forty male pups were included in the research, with thirty originating from mothers who were given a zinc-deficient diet (Groups 1, 2, and 3), and the remaining ten born to mothers fed a standard diet (Group 4). Subsequently, Group 1 was subjected to a zinc-deficient diet, Group 2 received a standard diet, Group 3 received zinc supplementation, and Group 4 served as the control group without any supplementation. Upon completion of the experimental phases of the study, all animals were sacrificed under general anesthesia, and samples of liver tissue were obtained. The levels of autotaxin, kallistatin, endocan, ZIP 14, and ZnT9 in these liver tissue samples were determined using the ELISA technique. In addition, histological examination was performed to evaluate tissue damage in the liver samples. In the group experiencing zinc deficiency, both endocan and autotaxin levels increased compared to the control group. With zinc supplementation, the levels of endocan and autotaxin returned to the values observed in the control group. Similarly, the suppressed levels of kallistatin, ZIP14, and ZnT9 observed in the zinc deficiency group were reversed with zinc supplementation. Likewise, the reduced levels of kallistatin, ZIP14, and ZnT9 seen in the zinc deficiency group were rectified with zinc supplementation. Moreover, the application of zinc partially ameliorated the heightened liver tissue damage triggered by zinc deficiency. This study is the pioneering one to demonstrate that liver tissue dysfunction induced by a marginal zinc-deficient diet in rats with marginal maternal zinc deficiency can be alleviated through zinc supplementation.

A novel generative adversarial networks modelling for the class imbalance problem in high dimensional omics data

Class imbalance remains a large problem in high-throughput omics analyses, causing bias towards the over-represented class when training machine learning-based classifiers. Oversampling is a common method used to balance classes, allowing for better generalization of the training data. More naive approaches can introduce other biases into the data, being especially sensitive to inaccuracies in the training data, a problem considering the characteristically noisy data obtained in healthcare. This is especially a problem with high-dimensional data. A generative adversarial network-based method is proposed for creating synthetic samples from small, high-dimensional data, to improve upon other more naive generative approaches. The method was compared with 'synthetic minority over-sampling technique' (SMOTE) and 'random oversampling' (RO). Generative methods were validated by training classifiers on the balanced data.

Zinc transporter 1 expression in hepatocellular carcinoma correlates with prognosis: A single-center retrospective study

OBJECTIVES

Zinc is crucial in the pathogenesis of hepatocellular carcinoma; however, no reports have examined its association with clinical parameters and zinc transporter 1 (ZNT1) expression intensity. This study aimed to assess the association between ZNT1 expression and prognosis in patients with hepatocellular carcinoma.

METHODS

This retrospective study included 65 patients who underwent surgical hepatocellular carcinoma resection at a single center between January 2011 and June 2015. ZNT1 expression on hepatocellular carcinoma cells from specimens was assessed using immunohistochemistry, and the relationship between its intensity and various clinical indexes was examined with univariate and multivariable analyses and the Mann-Whitney U, Kruskal-Wallis, Bonferroni, and log-rank tests.

RESULTS

ZNT1 expression on the hepatocellular carcinoma cell membrane was negative in 31 patients and positive in 34 patients, including nine patients showing strongly positive expression. Patients with and without ZNT1 expression had similar blood zinc concentrations, α-fetoprotein levels, protein induced by vitamin K absence-antagonist-II levels, gross classification, maximal tumor diameters, and background liver disease. The blood zinc concentrations were significantly lower in patients with strongly positive ZNT1 expression (57.0 ± 22.1 μg/dL) than in those with positive ZNT1 expression (71.1 ± 14.2 μg/dL; P = 0.015) or those with no ZNT1 expression (72.9 ± 14.1 μg/dL; P = 0.043). Overall survival was significantly shorter in ZNT1-expressing patients than in non-expressing patients (log-rank test, P = 0.024). Multivariable analysis using the Cox proportional hazards model identified maximal tumor diameter (hazard ratio, 1.018; 95% confidence interval, 1.002-1.034; P = 0.026) and ZNT1 expression status (hazard ratio, 2.082; 95% confidence interval, 1.196-3.621; P = 0.010) as prognostic contributing factors.

From zinc homeostasis to disease progression: Unveiling the neurodegenerative puzzle

Zinc is a crucial trace element in the human body, playing a role in various physiological processes such as oxidative stress, neurotransmission, protein synthesis, and DNA repair. The zinc transporters (ZnTs) family members are responsible for exporting intracellular zinc, while Zrt- and Irt-like proteins (ZIPs) are involved in importing extracellular zinc. These processes are essential for maintaining cellular zinc homeostasis. Imbalances in zinc metabolism have been linked to the development of neurodegenerative diseases. Disruptions in zinc levels can impact the survival and activity of neurons, thereby contributing to the progression of neurodegenerative diseases through mechanisms like cell apoptosis regulation, protein phase separation, ferroptosis, oxidative stress, and neuroinflammation. Therefore, conducting a systematic review of the regulatory network of zinc and investigating the relationship between zinc dysmetabolism and neurodegenerative diseases can enhance our understanding of the pathogenesis of these diseases. Additionally, it may offer new insights and approaches for the treatment of neurodegenerative diseases.

Zinc in Human Health and Infectious Diseases

During the last few decades, the micronutrient zinc has proven to be an important metal ion for a well-functioning immune system, and thus also for a suitable immune defense. Nowadays, it is known that the main cause of zinc deficiency is malnutrition. In particular, vulnerable populations, such as the elderly in Western countries and children in developing countries, are often affected. However, sufficient zinc intake and homeostasis is essential for a healthy life, as it is known that zinc deficiency is associated with a multitude of immune disorders such as metabolic and chronic diseases, as well as infectious diseases such as respiratory infections, malaria, HIV, or tuberculosis. Moreover, the modulation of the proinflammatory immune response and oxidative stress is well described. The anti-inflammatory and antioxidant properties of zinc have been known for a long time, but are not comprehensively researched and understood yet. Therefore, this review highlights the current molecular mechanisms underlying the development of a pro-/ and anti-inflammatory immune response as a result of zinc deficiency and zinc supplementation. Additionally, we emphasize the potential of zinc as a preventive and therapeutic agent, alone or in combination with other strategies, that could ameliorate infectious diseases.

Transcription Factor YY1 Ameliorates Liver Ischemia-reperfusion Injury Through Modulating the miR-181a-5p/ESR1/ERBB2 Axis

BACKGROUND

Liver ischemia/reperfusion injury (I/RI) is characterized by inflammatory actions. Understanding the mechanistic insights underpinning inflammation is critical to developing treatment strategies. In this study, we illustrated the mechanistic insights of transcription factor Yin-Yang 1 (YY1)-mediated microRNA (miR)-181a-5p/estrogen receptor alpha (ESR1)/epidermal growth factor receptor 2 (ERBB2) axis in liver I/RI.

METHODS

First, we established liver I/RI models in mice and hypoxia-reperfusion (H/R) cell models in mouse hepatocytes (AML12). Subsequently, the expression of YY1, miR-181a-5p, and ESR1 was determined in the 2 models. I/RI mouse models were further injected with lentivirus carrying oe-YY1' and H/R-exposed AML12 cells were subjected to a series of inhibitors, mimics, and shRNAs to validate the mechanisms of YY1 in controlling miR-181a-5p and ESR1 in liver I/RI.

RESULTS

Upregulated expression of miR-181a-5p and downregulated expression of YY1 were identified in the liver tissues of liver I/RI mice and H/R-exposed hepatocytes. Moreover, overexpression of YY1 inhibited the miR-181a-5p expression and thus repressed the H/R-induced hepatocyte apoptosis and inflammation. ESR1 was further validated as a target gene of miR-181a-5p and could be negatively regulated by miR-181a-5p. miR-181a-5p inhibition elevated ESR1 expression, which consequently enhanced the ERBB2 expression and reduced H/R-induced hepatocyte apoptosis and inflammation.

CONCLUSIONS

Overall, these findings highlighted that YY1 repressed the miR-181a-5p expression and stimulated ESR1-mediated activation of ERBB2, thereby ameliorating liver I/RI. This study provides insight into the development of novel targets for liver I/RI.