Molecular iodine inhibits the expression of stemness markers on cancer stem-like cells of established cell lines derived from cervical cancer

The correlation between iodine and metabolism: a review

Iodine is involved in the synthesis of thyroid hormones and plays a crucial role in human life. Both iodine deficiency and excess are common issues in certain populations. Iodine also has extrathyroidal effects on organs that can uptake it independently of thyroid hormones. Recently, multiple clinical studies have shown a connection between iodine intake and metabolic disorders, such as metabolic syndrome, obesity, diabetes, hypertension, and dyslipidemia. However, the results of these studies have been inconsistent, and the mechanisms behind these associations are still not well understood. Therefore, in this review, we aim to examine the recent research progress regarding the relationship between iodine and metabolic disorders, along with the relevant mechanisms.

Regulation and signaling pathways in cancer stem cells: implications for targeted therapy for cancer

Cancer stem cells (CSCs), initially identified in leukemia in 1994, constitute a distinct subset of tumor cells characterized by surface markers such as CD133, CD44, and ALDH. Their behavior is regulated through a complex interplay of networks, including transcriptional, post-transcriptional, epigenetic, tumor microenvironment (TME), and epithelial-mesenchymal transition (EMT) factors. Numerous signaling pathways were found to be involved in the regulatory network of CSCs. The maintenance of CSC characteristics plays a pivotal role in driving CSC-associated tumor metastasis and conferring resistance to therapy. Consequently, CSCs have emerged as promising targets in cancer treatment. To date, researchers have developed several anticancer agents tailored to specifically target CSCs, with some of these treatment strategies currently undergoing preclinical or clinical trials. In this review, we outline the origin and biological characteristics of CSCs, explore the regulatory networks governing CSCs, discuss the signaling pathways implicated in these networks, and investigate the influential factors contributing to therapy resistance in CSCs. Finally, we offer insights into preclinical and clinical agents designed to eliminate CSCs.

Protective effects of iodine on rat prostate inflammation induced by sex hormones and on the DU145 prostate cancer cell line treated with TNF

Molecular iodine (I₂) prevents oxidative stress and prostate hyperplasia induced by hyperandrogenism and reduces cell viability in prostate cancer cell lines. Here, we aimed to evaluate the protective effect of I₂ and testosterone (T) on hyperestrogenism-induced prostate inflammation. Additionally, the effects of I₂ and/or tumor necrosis factor (TNF) on cell viability and interleukin 6 (IL6) secretion were evaluated in a prostate cancer cell line (DU145). We also investigated whether the effects of I₂ on viability are peroxisome proliferator-activated receptor gamma (PPARG)-dependent. Castrated (Cx) rats received pellets of either 17β estradiol (E₂) or E₂ and T and were treated with I₂ (0.05%) in the drinking water for four weeks. The experimental groups were sham, Cx, Cx + E₂, Cx + E₂+I₂, Cx + E₂+T, and Cx + E₂+T + I₂. As expected, inflammation was triggered in the Cx + E₂ group (high inflammation score; increase in TNF and transcriptional activity of RELA [nuclear factor-kappa B p65 subunit]), and this effect was diminished in the Cx + E₂+T group (medium inflammation score and decrease in TNF). The lowest inflammation score (decrease of TNF and RELA and increase of PPARG) was obtained in the Cx + E₂+T + I₂ group. In DU145 cells, I₂ (400 μM) and TNF (10 ng/ml) additively reduced cell viability, and I₂ reduced the production of TNF-stimulated IL6. The PPARG antagonist (GW9662) did not inhibit the effects of I₂ on the loss of cell viability. In summary, our data suggest that I₂ and T exert a synergistic anti-inflammatory action on the normal prostate, and the interrelationship between I₂ and TNF leads to anti-proliferative effects in DU145 cells. PPARG does not seem to participate in the I₂-induced cell viability loss in the prostate.

The role of peroxisome proliferator-activated receptors in the tumor microenvironment, tumor cell metabolism, and anticancer therapy

Peroxisome proliferator-activated receptors (PPARs) have been extensively studied for over 3 decades and consist of three isotypes, including PPARα, γ, and β/δ, that were originally considered key metabolic regulators controlling energy homeostasis in the body. Cancer has become a leading cause of human mortality worldwide, and the role of peroxisome proliferator-activated receptors in cancer is increasingly being investigated, especially the deep molecular mechanisms and effective cancer therapies. Peroxisome proliferator-activated receptors are an important class of lipid sensors and are involved in the regulation of multiple metabolic pathways and cell fate. They can regulate cancer progression in different tissues by activating endogenous or synthetic compounds. This review emphasizes the significance and knowledge of peroxisome proliferator-activated receptors in the tumor microenvironment, tumor cell metabolism, and anti-cancer treatment by summarizing recent research on peroxisome proliferator-activated receptors. In general, peroxisome proliferator-activated receptors either promote or suppress cancer in different types of tumor microenvironments. The emergence of this difference depends on various factors, including peroxisome proliferator-activated receptor type, cancer type, and tumor stage. Simultaneously, the effect of anti-cancer therapy based on drug-targeted PPARs differs or even opposes among the three peroxisome proliferator-activated receptor homotypes and different cancer types. Therefore, the current status and challenges of the use of peroxisome proliferator-activated receptors agonists and antagonists in cancer treatment are further explored in this review.

Signaling pathways in the regulation of cancer stem cells and associated targeted therapy

Cancer stem cells (CSCs) are defined as a subpopulation of malignant tumor cells with selective capacities for tumor initiation, self-renewal, metastasis, and unlimited growth into bulks, which are believed as a major cause of progressive tumor phenotypes, including recurrence, metastasis, and treatment failure. A number of signaling pathways are involved in the maintenance of stem cell properties and survival of CSCs, including well-established intrinsic pathways, such as the Notch, Wnt, and Hedgehog signaling, and extrinsic pathways, such as the vascular microenvironment and tumor-associated immune cells. There is also intricate crosstalk between these signal cascades and other oncogenic pathways. Thus, targeting pathway molecules that regulate CSCs provides a new option for the treatment of therapy-resistant or -refractory tumors. These treatments include small molecule inhibitors, monoclonal antibodies that target key signaling in CSCs, as well as CSC-directed immunotherapies that harness the immune systems to target CSCs. This review aims to provide an overview of the regulating networks and their immune interactions involved in CSC development. We also address the update on the development of CSC-directed therapeutics, with a special focus on those with application approval or under clinical evaluation.

CD276 (B7H3) improve cancer stem cells formation in cervical carcinoma cell lines

Background

Cancer stem cells (CSCs) have been considered as a potential therapeutic target for cervical carcinoma. CD 276 is a well-known immune check point molecular, but its relationship with cervical CSCs was still unclear.

Methods

HeLa cell lines were obtained as cervical carcinoma in vitro model. HeLa cell Sphere formation culture was performed and CD276, OCT4 and SOX2 expression were determined by RT-qPCR. Transiently transfection and siRNA interference were used to modify CD276 expression. HeLa cell colony has been counted and cell proliferation was assessed by MTT assay. The relationship between CD276 and chemotherapy resistance of HeLa cell were evaluated by cisplatin treatment. Additionally, the mice model of xenograft tumor was established and CD276’s function was evaluated in vivo.

Results

Here, we demonstrate that the expression of CD276 is positively correlated with the amount of sphere-forming cells in HeLa cell lines. Overexpression of CD276 causes the inhibition of HeLa cells’ sphere formation, colony formation and cell viability. Meanwhile, the downregulation of CD276 leads to the other way. We also demonstrate that CD276 contributes to the chemotherapy resistance in the cell line. Furthermore, we verify the CD276’s function on HeLa xenotransplantation mice model.

Conclusions

These results suggest that CD276 elevates the self-renewal capacity of HeLa CSCs.

PPARs and Tumor Microenvironment: The Emerging Roles of the Metabolic Master Regulators in Tumor Stromal-Epithelial Crosstalk and Carcinogenesis

Peroxisome proliferator-activated receptors (PPARs) have been extensively studied for more than three decades. Consisting of three isotypes, PPARα, γ, and β/δ, these nuclear receptors are regarded as the master metabolic regulators which govern many aspects of the body energy homeostasis and cell fate. Their roles in malignancy are also increasingly recognized. With the growing interest in crosstalk between tumor stroma and epithelium, this review aims to highlight the current knowledge on the implications of PPARs in the tumor microenvironment. PPARγ plays a crucial role in the metabolic reprogramming of cancer-associated fibroblasts and adipocytes, coercing the two stromal cells to become substrate donors for cancer growth. Fibroblast PPARβ/δ can modify the risk of tumor initiation and cancer susceptibility. In endothelial cells, PPARβ/δ and PPARα are pro- and anti-angiogenic, respectively. Although the angiogenic role of PPARγ remains ambiguous, it is a crucial regulator in autocrine and paracrine signaling of cancer-associated fibroblasts and tumor-associated macrophages/immune cells. Of note, angiopoietin-like 4 (ANGPTL4), a secretory protein encoded by a target gene of PPARs, triggers critical oncogenic processes such as inflammatory signaling, extracellular matrix derangement, anoikis resistance and metastasis, making it a potential drug target for cancer treatment. To conclude, PPARs in the tumor microenvironment exhibit oncogenic activities which are highly controversial and dependent on many factors such as stromal cell types, cancer types, and oncogenesis stages. Thus, the success of PPAR-based anticancer treatment potentially relies on innovative strategies to modulate PPAR activity in a cell type-specific manner.

Molecular Iodine Has Extrathyroidal Effects as an Antioxidant, Differentiator, and Immunomodulator

Most investigations of iodine metabolism in humans and animals have focused on its role in thyroid function. However, considerable evidence indicates that iodine could also be implicated in the physiopathology of other organs. We review the literature that shows that molecular iodine (I₂) exerts multiple and complex actions on the organs that capture it, not including its effects as part of thyroid hormones. This chemical form of iodine is internalized by a facilitated diffusion system that is evolutionary conserved, and its effects appear to be mediated by a variety of mechanisms and pathways. As an oxidized component, it directly neutralizes free radicals, induces the expression of type II antioxidant enzymes, or inactivates proinflammatory pathways. In neoplastic cells, I₂ generates iodolipids with nuclear actions that include the activation of apoptotic pathways and the inhibition of markers related to stem cell maintenance, chemoresistance, and survival. Recently, I2 has been postulated as an immune modulator that depending on the cellular context, can function as an inhibitor or activator of immune responses. We propose that the intake of molecular iodine is increased in adults to at least 1 mg/day in specific pathologies to obtain the potential extrathyroid benefits described in this review.

Targeted Gene Delivery Therapies for Cervical Cancer

Despite being largely preventable through early vaccination and screening strategies, cervical cancer is the most common type of gynecological malignancy worldwide and constitutes one of the leading causes of cancer deaths in women. Patients with advanced or recurrent disease have a very poor prognosis; hence, novel therapeutic modalities to improve clinical outcomes in cervical malignancy are needed. In this regard, targeted gene delivery therapy is presented as a promising approach, which leads to the development of multiple strategies focused on different aspects. These range from altered gene restoration, immune system potentiation, and oncolytic virotherapy to the use of nanotechnology and the design of improved and enhanced gene delivery systems, among others. In the present manuscript, we review the current progress made in targeted gene delivery therapy for cervical cancer, the advantages and drawbacks and their clinical application. At present, multiple targeted gene delivery systems have been reported with encouraging preclinical results. However, the translation to humans has not yet shown a significant clinical benefit due principally to the lack of efficient vectors. Real efforts are being made to develop new gene delivery systems, to improve tumor targeting and to minimize toxicity in normal tissues.

Targeting cancer stem cell pathways for cancer therapy

Since cancer stem cells (CSCs) were first identified in leukemia in 1994, they have been considered promising therapeutic targets for cancer therapy. These cells have self-renewal capacity and differentiation potential and contribute to multiple tumor malignancies, such as recurrence, metastasis, heterogeneity, multidrug resistance, and radiation resistance. The biological activities of CSCs are regulated by several pluripotent transcription factors, such as OCT4, Sox2, Nanog, KLF4, and MYC. In addition, many intracellular signaling pathways, such as Wnt, NF-κB (nuclear factor-κB), Notch, Hedgehog, JAK-STAT (Janus kinase/signal transducers and activators of transcription), PI3K/AKT/mTOR (phosphoinositide 3-kinase/AKT/mammalian target of rapamycin), TGF (transforming growth factor)/SMAD, and PPAR (peroxisome proliferator-activated receptor), as well as extracellular factors, such as vascular niches, hypoxia, tumor-associated macrophages, cancer-associated fibroblasts, cancer-associated mesenchymal stem cells, extracellular matrix, and exosomes, have been shown to be very important regulators of CSCs. Molecules, vaccines, antibodies, and CAR-T (chimeric antigen receptor T cell) cells have been developed to specifically target CSCs, and some of these factors are already undergoing clinical trials. This review summarizes the characterization and identification of CSCs, depicts major factors and pathways that regulate CSC development, and discusses potential targeted therapy for CSCs.

Pterostilbene Suppresses both Cancer Cells and Cancer Stem-Like Cells in Cervical Cancer with Superior Bioavailability to Resveratrol

Increasing studies have reported that cancer stem cells (CSCs) play critical roles in therapeutic resistance, recurrence, and metastasis of tumors, including cervical cancer. Pterostilbene, a dimethylated derivative of resveratrol, is a plant polyphenol compound with potential chemopreventive activity. However, the therapeutic effect of pterostilbene against cervical CSCs remains unclear. In this study, we compared the anticancer effects of resveratrol and pterostilbene using both HeLa cervical cancer adherent and stem-like cells. Pterostilbene more effectively inhibited the growth and clonogenic survival, as well as metastatic ability of HeLa adherent cells than those of resveratrol. Moreover, the superior inhibitory effects of pterostilbene compared to resveratrol were associated with the enhanced activation of multiple mechanisms, including cell cycle arrest at S and G2/M phases, induction of ROS-mediated caspase-dependent apoptosis, and inhibition of matrix metalloproteinase (MMP)-2/-9 expression. Notably, pterostilbene exhibited a greater inhibitory effect on the tumorsphere-forming and migration abilities of HeLa cancer stem-like cells compared to resveratrol. This greater effect was achieved through more potent inhibition of the expression levels of stemness markers, such as CD133, Oct4, Sox2, and Nanog, as well as signal transducer and activator of transcription 3 signaling. These results suggest that pterostilbene might be a potential anticancer agent targeting both cancer cells and cancer stem-like cells of cervical cancer via the superior bioavailability to resveratrol.

Phloretin suppresses metastasis by targeting protease and inhibits cancer stemness and angiogenesis in human cervical cancer cells

BACKGROUND

Phloretin, a dihydrochalcone flavonoid, possesses anti-inflammatory activity and inhibits the growth of various cancers. However, the flavonoid's effect on cervical cancer metastasis and angiogenesis remains unknown.

PURPOSE

In this study, we provide molecular evidence associated with the antimetastatic and antiangiogenic effects of phloretin.

METHODS

In this study, the anti-invasive effect of phloretin (0-60 μM) in cervical cancer cells was evaluated using the Matrigel invasion assay, gelatin zymography, cell-matrix adhesion assay, wound healing assay, and Western blotting. Antiangiogenic potential of phloretin (0-100 μM) was assessed by the Matrigel tube formation assay. The in vivo antitumor effect of phloretin (10 or 20 mg/kg) was fed by oral gavage and determined using subcutaneous inoculation and tail vein injection in immunodeficient nude mice.

RESULTS

Phloretin (60 μM) showed marked suppression of invasion and migration through downregulation of matrix metalloproteinase (MMP)-2, MMP-3, and cathepsin S in human SiHa cervical cancer cells. Phloretin (60 μM) reversed the epithelial-mesenchymal transition induced by transforming growth factor-β1 and downregulated mesenchymal markers, such as fibronectin, vimentin, and RhoA. Phloretin (100 μM) treatment significantly inhibited the aldehyde dehydrogenase 1 activity of SiHa cells, reduced the self-renewal properties and stemness signatures of CD44 and Sox-2 in sphere-forming cervical cancer-derived tumor-initiating cells, and inhibited the invasion, MMP-2 activity, and tube formation capacity of human umbilical vein endothelial cells. The ability of phloretin (20 mg/kg) to suppress lung metastasis and tumor growth in SiHa cells was evidenced by tail vein injection and subcutaneous inoculation in a tumor xenograft model.

CONCLUSION

In summary, the findings indicate that phloretin inhibits the metastatic and angiogenic abilities and cancer stemness of SiHa cells, thereby suggesting that this flavonoid is a promising therapeutic agent for the treatment of human cervical cancer cells.

Cancer stem cell impact on clinical oncology

Cancer is a widespread worldwide chronic disease. In most cases, the high mortality rate from cancer correlates with a lack of clear symptoms, which results in late diagnosis for patients, and consequently, advanced tumor disease with poor probabilities for cure, since many patients will show chemo- and radio-resistance. Several mechanisms have been studied to explain chemo- and radio-resistance to anti-tumor therapies, including cell signaling pathways, anti-apoptotic mechanisms, stemness, metabolism, and cellular phenotypes. Interestingly, the presence of cancer stem cells (CSCs), which are a subset of cells within the tumors, has been related to therapy resistance. In this review, we focus on evaluating the presence of CSCs in different tumors such as breast cancer, gastric cancer, lung cancer, and hematological neoplasias, highlighting studies where CSCs were identified in patient samples. It is evident that there has been a great drive to identify the cell surface phenotypes of CSCs so that they can be used as a tool for anti-tumor therapy treatment design. We also review the potential effect of nanoparticles, drugs, natural compounds, aldehyde dehydrogenase inhibitors, cell signaling inhibitors, and antibodies to treat CSCs from specific tumors. Taken together, we present an overview of the role of CSCs in tumorigenesis and how research is advancing to target these highly tumorigenic cells to improve oncology patient outcomes.