Nickel is a transition metal that is widely distributed in the environment. Nickel compounds are classified as Group 1 carcinogens (human carcinogens) by the International Agency for Research on Cancer (IARC). Despite extensive studies, the molecular mechanisms underlying nickel-induced carcinogenesis remain incompletely understood. Maternally Expressed Gene 3 (MEG3) is the first long non-coding RNA (lncRNA) identified as a tumor suppressor. Previous studies have shown that downregulation of MEG3 increases HIF-1α expression in human bronchial epithelial BEAS-2B cells chronically exposed to nickel. In the present study, we observed that MEG3 expression is markedly reduced in nickel-transformed cells. Dysregulation of Runt-Related Transcription Factor 2 (RUNX2) has also been implicated in multiple cancer types. Previous studies have demonstrated that RUNX2 is upregulated in nickel-induced malignantly transformed BEAS-2B cells. Consistent with these findings, we observed that chronic exposure of BEAS-2B cells to low-dose nickel increases both RUNX2 mRNA and protein expression, accompanied by elevated expression of mesenchymal markers and enhanced migratory and invasive capacities. Overexpression of MEG3 in nickel-transformed cells reduces RUNX2 protein levels and reverses the alterations of epithelial-mesenchymal transition (EMT) markers, resulting in decreased cell migration and invasion in nickel-transformed cells. Similarly, silencing RUNX2 reverses the expression of EMT markers and suppresses the migratory and invasive capacities of nickel-transformed cells. Notably, shRNA-mediated RUNX2 knockdown increases MEG3 expression, indicating reciprocal regulation between MEG3 and RUNX2 in nickel-transformed cells. Collectively, our findings demonstrate that MEG3 and RUNX2 form a reciprocally regulated signaling axis that contributes to EMT, thereby promoting migration and invasion in nickel-transformed cells. These results identify MEG3 and RUNX2 as interconnected biomarkers and potential therapeutic targets for cancer prevention and treatment, warranting further mechanistic investigation.

Lung cancer is the leading cause of cancer deaths among American men, even though various treatments are available. The discovery and use of new alternative drugs to treat lung cancers are needed to reduce lung cancer mortality. Phytochemicals are potentially desirable therapeutic agents due to their better safety profiles. Isorhapontigenin (ISO) is an orally bioavailable dietary stilbene. Our studies show that treatment with ISO inhibits human lung cancer cell growth, angiogenesis, invasion, and migration. Neural precursor cell expressed developmentally downregulated 9 (NEDD9), a multi-domain scaffolding protein, regulates various processes crucial for tumorigenesis and metastasis. Our results show that NEDD9 is upregulated in the lung tissues from human lung adenocarcinomas (LUADs) and squamous-cell carcinomas (LUSCs) compared to normal lungs. Overexpression of NEDD9 elevates the invasion and migration of human lung cancer cells. Treatment of human lung cancer cells with ISO decreases NEDD9 protein levels. Our studies have also demonstrated that NEDD9 positively regulates angiogenesis, an essential factor in cancer progression. ISO treatment reduces angiogenesis. Moreover, ISO reduces the protein levels of hypoxia-inducible factor-1α (HIF-1α), a transcription factor critical for angiogenesis. Aberrant high expression of β-Catenin leads to various diseases including cancer. Our results show that ISO treatment reduces the activation of β-Catenin through the downregulation of NEDD9. Studies indicate that ISO decreases NEDD9, causing the suppression of cell growth, angiogenesis, invasion, and migration of human lung cancer cells. ISO is a potent therapeutic agent for lung cancer treatment.

Numerous studies have shown that exposure to cadmium [Cd(II)] contributes to the development of cancers in the lung and other organs. Cd(II) compounds are classified as confirmed human carcinogens; however, the mechanisms underlying Cd(II)-induced carcinogenesis remain poorly understood. Small nucleolar RNA host gene 1 (SNHG1), a long non-coding RNA (lncRNA), has been identified as an oncogene. In this study, we investigated the role of SNHG1 in the invasion and migration of Cd(II)-transformed cells. Our findings revealed that SNHG1 expression was significantly elevated in Cd(II)-transformed cells compared to their passage-matched normal BEAS-2B counterparts. Silencing SNHG1 reduced the invasive and migratory capacities of Cd(II)-transformed cells and inhibited malignant transformation induced by long-term Cd exposure. Notably, ectopic expression of SNHG1 alone in BEAS-2B cells was sufficient to drive malignant transformation and enhance invasion and migration, underscoring its oncogenic potential. SRY-box 2 (Sox2), a transcription factor implicated in cancer cell proliferation, invasion, and migration, was found to be upregulated in Cd(II)-transformed cells, while SNHG1 knockdown led to decreased Sox2 protein levels. Similarly, ras-related C3 botulinum toxin substrate 1 (Rac1), a key regulator of cytoskeletal dynamics linked to tumor growth, invasion, and metastasis, was also elevated in Cd(II)-transformed cells. Knockdown of SNHG1 reduced Rac1 protein levels, and Rac1 knockout significantly suppressed invasion and migration. Additionally, we observed increased expression of Slug, a key transcription factor invovlved in epithelial-mesenchymal transition (EMT), and decreased expression of its downstream target E-cadherin in Cd(II)-transformed cells. Collectively, these results demonstrate that elevated SNHG1 promotes the expression of Sox2, Rac1, and Slug, thereby driving the invasive and migratory behavior of Cd(II)-transformed cells.

Cancer cells release extracellular vesicles (EVs) that participate in altering the proximal tumor environment and distal tissues to promote cancer progression. Chronic exposure to nickel (Ni), a human group I carcinogen, results in epigenetic changes that promotes epithelial to mesenchymal transition (EMT). Cells that undergo EMT demonstrate various molecular changes, including elevated levels of the mesenchymal cadherin N-cadherin (N-CAD) and the transcription factor Zinc finger E-box binding homeobox 1 (ZEB1). Moreover, the molecular changes following EMT induce changes in cellular behavior, including anchorage-independent growth, which contributes to cancer cells detaching from tumor bulk during the metastatic process. Here, we present data demonstrating that EVs from Ni-exposed cells induce EMT in recipient BEAS-2B cells in the absence of Ni. Moreover, we show evidence that the EVs from Ni-altered cells package the transcription factor nuclear protein 1 (NUPR1), a transcription factor associated with Ni exposure and cancer progression. Moreover, our data demonstrates that the NUPR1 in the EVs becomes part of the recipient cell proteomic milieu and carry the NUPR1 to the nuclear space of the recipient cell. Interestingly, knockdown of NUPR1 in Ni-transformed cells suppressed NUPR1 packaging in the EVs, and nanoparticle tracking analysis (NTA) demonstrated decreased EV release. Reduction of NUPR1 in EVs resulted in diminished EMT capacity that resulted in decreased anchorage independent growth. This study is the first to demonstrate the role of NUPR1 in extracellular vesicle-mediate cancer progression.

Abstract Lung cancer is the second most common cancer in both men and women in the United States. Even though treatments including chemotherapy, targeted therapy, and immunotherapy are available, lung cancer has been the leading cause of cancer deaths. The discovery and evaluation of new alternative medications targeting lung cancer are tremendously important for reducing lung cancer mortality. Phytochemicals are very desirable chemotherapeutic agents because of their greater safety profile. Isorhapontigenin (ISO), one of the oral bioavailable dietary stilbenes, can be found in various natural resources. Our result showed that ISO treatment suppressed the invasion and migration of human lung cancer cell lines A549, H23, and H1299 cells. Long non-coding RNA Maternally Expressed Gene 3 (MEG3), a tumor suppressor, was downregulated or lost in various primary human tumor tissues and cancer cell lines. The low expression of MEG3 is correlated with poor prognosis in non-small cell lung cancer (NSCLC). Our results showed that ISO treatment elevated MEG3 levels in these lung cancer cell lines. One of the major genetic causes of lung cancer is mutations in the epidermal growth factor receptor (EGFR) receptor tyrosine kinase, resulting in activation of EGFR which activates several signaling pathways involved in cell proliferation, drug sensitivity, and angiogenesis. Our results showed that ISO decreased the phosphorylation and protein levels of EGFR in A549 cells. Hypoxia-inducible factor-1α (HIF-1α), a transcription factor, regulates the activation of several genes involved in cell proliferation, angiogenesis, invasion, and metastasis. Our results showed that ISO decreased HIF-1α protein levels. Overexpression of MEG3 reduced p-EGFR and HIF-1α, indicating MEG3 negatively regulated EGFR and HIF-1α. Our data also showed that inhibition of EGFR by its tyrosine inhibitor decreased HIF-1α, suggesting that EGFR positively regulates HIF-1α. In cancer cells, Epithelial-Mesenchymal Transition(EMT) endows cells with increased invasiveness and tumor-initiating capacity, contributing to metastasis and resistance to therapeutics. Slug, one of the EMT transcription factors maintains cell plasticity during carcinogenesis. Our results showed that ISO treatment decreased Slugprotein levels in A549 and H23 cells. Transcription factor SOX2 regulates cancer cell proliferation, EMT, migration, invasion, metastasis, tumor initiation, cancer stem cell formation as well as resistance to apoptosis and therapy. Our results showed that ISO decreased SOX2 expression. Knockdown of MEG3 increased the expressions of Slug and SOX2, indicating that MEG3 negatively regulates Slug and SOX2. In conclusion, ISO elevated MEG3, inhibiting EGFR, HIF-1α, Slug, and SOX2, suppressing the migration and invasion of lung cancer cells. Citation Format: Sophia Shi, Zhuo Zhang, Jingxia Li, Huailu Tu, Max Costa. Isoharpontigenin inhibits migration and invasion of lung cancer cells through MEG3/EGFR pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB049.

Lung cancer is the leading cause of cancer-related death worldwide; however, the mechanism of lung carcinogenesis has not been clearly defined. Chronic exposure to hexavalent chromium [Cr(VI)], a common environmental and occupational pollutant, causes lung cancer, representing an important lung cancer etiology factor. The mechanism of how chronic Cr(VI) exposure causes lung cancer remains largely unknown. By using cell culture and mouse models and bioinformatics analyses of human lung cancer gene expression profiles, this study investigated the mechanism of Cr(VI)-induced lung carcinogenesis. A new mouse model of Cr(VI)-induced lung carcinogenesis was developed as evidenced by the findings showing that a 16-week Cr(VI) exposure (CaCrO4, 100 μg per mouse once per week) via oropharyngeal aspiration induced lung adenocarcinomas in male and female A/J mice, whereas none of the sham-exposed control mice had lung tumors. Mechanistic studies revealed that chronic Cr(VI) exposure activated the non-canonical NFκB pathway through the long non-coding RNA (lncRNA) ABHD11-AS1/deubiquitinase USP15-mediated tumor necrosis factor receptor-associated factor 3 (TRAF3) down-regulation. The non-canonical NFκB pathway activation increased the interleukin 6 (IL-6)/Janus kinase (Jak)/signal transducer and activator of transcription 3 (Stat3) signaling. The activation of the IL-6/Jak signaling axis by Cr(VI) exposure not only promoted inflammation but also stabilized the immune checkpoint molecule programmed death-ligand 1 (PD-L1) protein in the lungs, reducing T lymphocyte infiltration to the lungs. Given the well-recognized critical role of PD-L1 in inhibiting anti-tumor immunity, these findings suggested that the lncRNA ABHD11-AS1-mediated non-canonical NFκB pathway activation and PD-L1 up-regulation may play important roles in Cr(VI)-induced lung carcinogenesis.

Bladder cancer, the most common malignancy of the urinary tract, has a poor overall survival rate when the tumor becomes muscle invasive. The discovery and evaluation of new alternative medications targeting high-grade muscle invasive bladder cancer (MIBC) are of tremendous importance in reducing bladder cancer mortality. Isorhapontigenin (ISO), a stilbene derivative from the Chinese herb Gnetum cleistostachyum, exhibits a strong anti-cancer effect on MIBCs. Here, we report the whole transcriptome profiling of ISO-treated human bladder cancer T24 cells. A total of 1047 differentially expressed genes (DEGs) were identified, including 596 downregulated and 451 upregulated genes. Functional annotation and pathway analysis revealed that ISO treatment induced massive changes in gene expression associated with cell movement, migration, invasion, metabolism, proliferation, and angiogenesis. Additionally, ISO treatment-activated genes involved in the inflammatory response but repressed genes involved in hypoxia signaling, glycolysis, the actin cytoskeleton, and the tumor microenvironment. In summary, our whole transcriptome analysis demonstrated a shift in metabolism and altered actin cytoskeleton in ISO-treated T24 cells, which subsequently contribute to tumor microenvironment remodeling that suppresses tumor growth and progression.

Dysregulation of MOF (also known as MYST1, KAT8), a highly conserved H4K16 acetyltransferase, plays important roles in human cancers. However, its expression and function in esophageal squamous cell carcinoma (ESCC) remain unknown. Here, we report that MOF is highly expressed in ESCC tumors and predicts a worse prognosis. Depletion of MOF in ESCC significantly impedes tumor growth and metastasis both in vitro and in vivo, whereas ectopic expression of MOF but not catalytically inactive mutant (MOF-E350Q) promotes ESCC progression, suggesting that MOF acetyltransferase activity is crucial for its oncogenic activity. Further analysis reveals that USP10, a deubiquitinase highly expressed in ESCC, binds to and deubiquitinates MOF at lysine 410, which protects it from proteosome-dependent protein degradation. MOF stabilization by USP10 promotes H4K16ac enrichment in the ANXA2 promoter to stimulate ANXA2 transcription in a JUN-dependent manner, which subsequently activates Wnt/β-Catenin signaling to facilitate ESCC progression. Our findings highlight a novel USP10/MOF/ANXA2 axis as a promising therapeutic target for ESCC.

p97 is a ubiquitin-targeted ATP-dependent segregase that regulates proteostasis, in addition to a variety of other cellular functions. Previously, we demonstrated that p97 negatively regulates NRF2 by extracting ubiquitylated NRF2 from the KEAP1-CUL3-RBX1 E3 ubiquitin ligase complex, facilitating proteasomal destruction. In the current study, we identified p97 as an NRF2-target gene that contains a functional ARE, indicating the presence of an NRF2-p97-NRF2 negative feedback loop that maintains redox homeostasis. Using CRISPR/Cas9 genome editing, we generated endogenous p97 ARE-mutated BEAS-2B cell lines. These p97 ARE-mutated cell lines exhibit altered expression of p97 and NRF2, as well as a compromised response to NRF2 inducers. Importantly, we also found a positive correlation between NRF2 activation and p97 expression in human cancer patients. Finally, using chronic arsenic-transformed cell lines, we demonstrated a synergistic effect of NRF2 and p97 inhibition in killing cancer cells with high NRF2 and p97 expression. Our study suggests dual upregulation of NRF2 and p97 occurs in certain types of cancers, suggesting that inhibition of both NRF2 and p97 could be a promising treatment strategy for stratified cancer patients.

Supplementary Table S1. Baseline characteristics of FACT participants with vs. without PTHM measures;Supplementary Table S2. Baseline characteristics of FACT participants with vs. without RBC folate measures; Supplementary Table S3. Associations (β (95% CI)) between OCM indices and PTHMs by sex in FACT participants, comparing models additionally adjusting for BMI; Supplementary Table S4. Associations (β (95% CI)) between OCM indices and PTHMs by sex in FACT participants, comparing models additionally adjusting for blood arsenic; Supplementary Table S5. Associations (β (95% CI))a between OCM indices and PTHMs by sex in FACT participants, comparing nutrients in model alone vs. included simultaneously;Supplementary Table S6. Associationsa between plasma OCM indices and PTHMs stratified by age and sex;Supplementary Table S7. Associationsa between plasma OCM indices and PTHMs stratified by blood arsenic and sex; Supplementary Table S8. Associationsa between changes in OCM indices and changes in PTHMs from baseline to week 12; Supplementary Figure S1. Sex-Specific Associations between OCM Indices and PTHMs in FACT Participants with RBC Folate Measures

Objective: It is well established that exposure of human skin to airborne pollution, particularly in the form of particulate matter sized 2.5 mu m (PM2.5), is associated with oxidative stress, DNA damage and inflammation, leading to premature signs of skin aging. Because much of the damage results from oxidative stress, we examined the effects of a topical composition containing three antioxidants in an in vitro model system to assess the potential for amelioration of premature aging. The use of multiple antioxidants was of interest based on the typical composition of therapeutic skincare products. It is important to determine the efficacy of multiple antioxidants together and develop a short-term assay for larger scale efficacy testing. Methods: Normal human epidermal keratinocytes were exposed to a rural-derived source of PM2.5 in the presence and absence of an antioxidant mixture of resveratrol, niacinamide and GHK peptide. Endpoints related to inflammation, premature aging and carcinogenicity were monitored after 5 h of exposure and included IL-6, CXCL10, MMP-1 and NRF2. Differentially expressed genes were monitored by RNA-seq. Results: Pre-treatment of keratinocytes with the antioxidant preparation in the absence of PM(2.)5 reduced baseline levels of MMP-1, IL-6 and CYP1A1 and reduced PM2.5-induced increases in all four endpoints, MMP-1, IL-6, CXCL10 and CYP1A1. Antioxidants significantly increased NRF2 protein in the presence of PM2.5, indicating a protective response. RNA-seq interrogation of antioxidant-treated cells further showed increased expression of NRF2 inducible genes. The expression of CYP1A1 and genes related to aryl hydrocarbon activation were induced by PM2.5 and suppressed by antioxidants. Conclusions: Specific signalling pathways known to be correlated with skin inflammation and aging were examined based on their suitability for use in efficacy testing for the prevention of skin damage due to ambient hydrocarbon pollution. Endpoints examined after only 5 h of exposure provide a useful method amenable to high through-put screening. The results obtained reinforce the concept that a multiple antioxidant preparation, topically applied, may reduce pro-inflammatory signalling and cellular damage and thereby reduce premature skin aging due to exposure to rural-derived airborne pollution.

Supplementary Methods, Figure Legends 1-2, Table Legends 1-4 from Hypoxia Induces Trimethylated H3 Lysine 4 by Inhibition of JARID1A Demethylase

Arsenic ranks at the top among all toxic metals and poses a serious threat to human health. Inorganic arsenite and arsenate compounds have been classified as human carcinogens in various types of cancers. Maternally expressed gene 3 (MEG3), a tumor suppressor that is commonly lost in cancer, was investigated in this study for its role in the migration and invasion of arsenic-transformed cells. Our results showed that MEG3 was downregulated in both arsenic-transformed cells (As-T) and cells treated with low doses of arsenic for three months (As-treated). The analysis using TCGA dataset revealed that MEG3 expression was significantly reduced in the tumor tissues from human lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) compared to normal lung tissues. The results from the methylation-specific PCR (MSP) assay demonstrated enhanced methylation in the MEG3 promoters in both As-T and As-treated cells, indicating that increased methylation of the MEG3 promoter caused MEG3 downregulation in these cells. Moreover, As-T cells displayed increased migration and invasion and higher levels of NAD(P)H quinone dehydrogenase 1 (NQO1) and fascin actin-bundling protein 1 (FSCN1). Consistently, the results from immunohistochemistry staining showed that both NQO1 and FSCN1 are highly expressed in human lung squamous cell carcinoma tissues compared to those in normal lungs. Knockdown of MEG3 in normal BEAS-2B cells also led to increased migration and invasion, along with elevated levels of NQO1 and FSCN1. The negative regulation of MEG3 on FSCN1 was restored by NQO1 overexpression in both As-T and BEAS-2B cells. The results from immunoprecipitation assays confirmed the direct binding of NQO1 to FSCN1. Overexpression of NQO1 increased migration and invasion abilities in BEAS-2B cells, while knockdown of NQO1 by its shRNA reduced these two hallmarks of cancer. Interestingly, the reduced migration and invasion by NQO1 knockdown were restored by FSCN1. Collectively, the loss of MEG3 upregulated NQO1, which in turn stabilized FSCN1 protein through its direct binding, resulting in elevated migration and invasion in arsenic-transformed cells.

Aluminum, beryllium, cobalt, copper, germanium, iron, lead, manganese, molybdenum, scandium, selenium, silicon, thorium, tin, titanium, vanadium, and zinc have been evaluated for their carcinogenic and genotoxic activity. Palladium, tellurium, and thallium have also been considered, but in less detail.

Supplementary Figures 1-2 from Hypoxia Induces Trimethylated H3 Lysine 4 by Inhibition of JARID1A Demethylase

The detrimental effects of gestational and lactational exposure to adverse chemical agents are gathering increasing attention. In our study, the presence of toxic heavy metals in several prenatal vitamins from six brands available in supermarkets and pharmacies was measured using ICP mass spectrometry. Several toxic heavy metals were detected, some at levels that could have potential toxicity to the fetus and the mother as well. Previous studies have also detected toxic heavy metals in prenatal and other vitamins. One of the reasons for toxic heavy metals in "natural vitamins" sold to consumers is that they are produced from naturally grown material and not synthesized. They are likely exposed to the heavy metals from the ground that they are grown in and there has not been any significant attempt to get rid of them before the vitamin pill was sold to consumers. Thus, this problem is not an isolated issue and regulatory agencies should be dealing more aggressively than they have been doing. In fact, several papers have already been published showing similar findings as we are reporting here. The vitamin pills we analyzed have elevated levels of boron, aluminum, molybdenum, barium, lead, titanium, nickel, arsenic, strontium, and cadmium. The levels of total chromium were also elevated but we did not separately determine Cr(III) and the much more hazardous Cr(VI), because of the tedious procedure required to separate these two forms of Cr.

Hexavalent chromium [Cr(VI)] is extensively used in many industrial processes. Previous studies reported that Cr(VI) exposures during early embryonic development reduced body weight with musculoskeletal malformations in rodents while exposures in adult mice increased serum creatine kinase activity, a marker of muscle damage. However, the impacts of Cr(VI) on muscle differentiation remain largely unknown. Here, we report that acute exposures to Cr(VI) in mouse C2C12 myoblasts inhibit myogenic differentiation in a dose-dependent manner. Exposure to 2 μM of Cr(VI) resulted in delayed myotube formation, as evidenced by a significant decrease in myotube formation and expression of muscle-specific markers, such as muscle creatine kinase (Mck), Myocyte enhancer factor 2 (Mef2), Myomaker (Mymk) and Myomixer (Mymx). Interestingly, exposure to 5 μM of Cr(VI) completely abolished myotube formation in differentiating C2C12 cells. Moreover, the expression of key myogenic regulatory factors (MRFs) including myoblast determination protein 1 (MyoD), myogenin (MyoG), myogenic factor 5 (Myf5), and myogenic factor 6 (Myf6) were significantly altered in Cr(VI)-treated cells. The inhibitory effect of Cr(VI) on myogenic differentiation was further confirmed in freshly isolated mouse satellite cells, a stem cell population essential for adult skeletal muscle regeneration. Furthermore, Cr(VI) exposure to fully differentiated C2C12 myotubes resulted in a decrease in myotube diameter, which was exacerbated upon co-treatment with dexamethasone. Together, our results demonstrate that Cr(VI) inhibits myogenic differentiation and induces myotube atrophy in vitro.