Search

Purpose To evaluate the effect of reconstruction and noise removal algorithms on the accuracy and precision of iodine concentration (CI) quantified with subtracted micro-computed tomography (micro-CT). Procedures Two reconstruction algorithms were evaluated: a filtered backprojection (FBP) algorithm and a simultaneous iterative reconstruction technique (SIRT) algorithm. A 3D bilateral filter (BF) was used for noise removal. A phantom study evaluated and compared the image quality, and the accuracy and precision of CI in four scenarios: filtered FBP, filtered SIRT, non-filtered FBP, and non-filtered SIRT. In vivo experiments were performed in an animal model of chemically-induced mammary cancer. Results Linear relationships between the measured and nominal CI values were found for all the scenarios in the phantom study (R2 > 0.95). SIRT significantly improved the accuracy and precision of CI compared to FBP, as given by their lower bias (adj. p-value = 0.0308) and repeatability coefficient (adj. p-value in vivo studies showed that CI is a reproducible imaging parameter for all the scenarios (Pearson r > 0.99, p-value in vivo study when SIRT and BF algorithms were used. Conclusions SIRT and BF algorithms improved the accuracy and precision of CI compared to FBP and non-filtered images, which encourages their use in subtracted micro-CT imaging.

Thyroxine (T4) promotes cell proliferation and tumor growth in prostate cancer models, but it is unknown if the increase in the triiodothyronine (T3)/T4 ratio could attenuate prostate tumor development. We assessed T3 effects on thyroid response, histology, proliferation, and apoptosis in the prostate of wild-type (WT) and TRAMP (transgenic adenocarcinoma of the mouse prostate) mice. Physiological doses of T3 were administered in the drinking water (2.5, 5 and 15 µg/100 g body weight) for 6 weeks. None of the doses modified the body weight or serum levels of testosterone, but all of them reduced serum T4 levels by 50%, and the highest dose increased the T3/T4 ratio in TRAMP. In WT, the highest dose of T3 decreased cyclin D1 levels (immunohistochemistry) but did not modify prostate weight or alter the epithelial morphology. In TRAMP, this dose reduced tumor growth by antiproliferative mechanisms independent of apoptosis, but it did not modify the intraluminal or fibromuscular invasion of tumors. In vitro, in the LNCaP prostate cancer cell line, we found that both T3 and T4 increased the number of viable cells (Trypan blue assay), and only T4 response was fully blocked in the presence of an integrin-binding inhibitor peptide (RGD, arginine-glycine-aspartate). In summary, our data show that the prostate was highly sensitive to physiological T3 doses and suggest that in vivo, an increase in the T3/T4 ratio could be associated with the reduced weight of prostate tumors. Longitudinal studies are required to understand the role of thyroid hormones in prostate cancer progression.

Neuroblastoma (NB) is the most common solid childhood tumor, and all-trans retinoic acid (ATRA) is used as a treatment to decrease minimal residual disease. Molecular iodine (I2) induces differentiation and/or apoptosis in several neoplastic cells through activation of PPARγ nuclear receptors. Here, we analyzed whether the coadministration of I2 and ATRA increases the efficacy of NB treatment. ATRA-sensitive (SH-SY5Y), partially-sensitive (SK-N-BE(2)), and non-sensitive (SK-N-AS) NB cells were used to analyze the effect of I2 and ATRA in vitro and in xenografts (Foxn1 nu/nu mice), exploring actions on cellular viability, differentiation, and molecular responses. In the SH-SY5Y cells, 200 μM I2 caused a 100-fold (0.01 µM) reduction in the antiproliferative dose of ATRA and promoted neurite extension and neural marker expression (tyrosine hydroxylase (TH) and tyrosine kinase receptor alpha (Trk-A)). In SK-N-AS, the I2 supplement sensitized these cells to 0.1 μM ATRA, increasing the ATRA-receptor (RARα) and PPARγ expression, and decreasing the Survivin expression. The I2 supplement increased the mitochondrial membrane potential in SK-N-AS suggesting the participation of mitochondrial-mediated mechanisms involved in the sensibilization to ATRA. In vivo, oral I2 supplementation (0.025%) synergized the antitumor effect of ATRA (1.5 mg/kg BW) and prevented side effects (body weight loss and diarrhea episodes). The immunohistochemical analysis showed that I2 supplementation decreased the intratumoral vasculature (CD34). We suggest that the I2 + ATRA combination should be studied in preclinical and clinical trials to evaluate its potential adjuvant effect in addition to conventional treatments.

We evaluated the effect of oral molecular iodine supplementation and shock wave application under three different conditions on human MDA-MB231 cancer cell xenografts. After tumor volume reached 1 cm3, mice were randomly assigned to groups and treated for 3 weeks. The results revealed that high-dose shock wave treatment (150 shock waves at a pressure of 21.7 MPa, SW150/21.7) generated tissue lesions without decreasing tumor growth, canceled the antineoplastic action of iodine and promoted pro-tumor conditions (increased hypoxia-induced factor [HIF] and vascular endothelial growth factor [VEGF]). In contrast, moderate (SW35/21.7) and low (SW35/9.9) doses of shock waves had significant antineoplastic effects and, in combination with iodine supplement, attenuated the aggressiveness of these cells by decreasing expression of the markers of stem cells (CD44 and Sox2) and invasion (HIF and VEGF). These results allow us to propose the combination of shock waves and iodine as a possible adjuvant in breast cancer therapy.

Pancreatitis has been implicated in the development and progression of type 2 diabetes and cancer. The pancreas uptakes molecular iodine (I2), which has anti-inflammatory and antioxidant effects. The present work analyzes whether oral I2 supplementation prevents the pancreatic alterations promoted by low doses of streptozotocin (STZ). CD1 mice (12 weeks old) were divided into the following groups: control; STZ (20 mg/kg/day, i.p. for five days); I2 (0.2 mg/Kg/day in drinking water for 15 days); and combined (STZ + I2). Inflammation (Masson’s trichrome and periodic acid–Schiff stain), hyperglycemia, decreased β-cells and increased α-cells in pancreas were observed in male and female animals with STZ. These animals also showed pancreatic increases in immune cells and inflammation markers as tumor necrosis factor-alpha, transforming growth factor-beta and inducible nitric oxide synthase with a higher amount of activated pancreatic stellate cells (PSCs). The I2 supplement prevented the harmful effect of STZ, maintaining normal pancreatic morphometry and functions. The elevation of the nuclear factor erythroid-2 (Nrf2) and peroxisome proliferator-activated receptor type gamma (PPARγ) contents was associated with the preservation of normal glycemia and lipoperoxidation. In conclusion, a moderated supplement of I2 prevents the deleterious effects of STZ in the pancreas, possibly through antioxidant and antifibrotic mechanisms including Nrf2 and PPARγ activation.

Lung cancer has the highest mortality among all types of cancer; during its development, cells can acquire neural and endocrine properties that affect tumor progression by releasing several factors, some acting as immunomodulators. Neuroendocrine phenotype correlates with invasiveness, metastasis, and low survival rates. This work evaluated the effect of neuroendocrine differentiation of adenocarcinoma on the mouse immune system. A549 cells were treated with FSK (forskolin) and IBMX (3-Isobutyl-1-methylxanthine) for 96 h to induce neuroendocrine differentiation (NED). Systemic effects were assessed by determining changes in circulating cytokines and immune cells of BALB/c mice immunized with PBS, undifferentiated A549 cells, or neuroendocrine A549NED cells. A549 cells increased circulating monocytes, while CD4+CD8− and CD4+CD8+ T cells increased in mice immunized with neuroendocrine cells. IL-2 and IL-10 increased in mice that received untreated A549 cells, suggesting that the immune system mounts a regulated response against adenocarcinoma, which did not occur with A549NED cells. Cocultures demonstrated the cytotoxic capacity of PBMCs when confronted with A549 cells, while in the presence of neuroendocrine cells they not only were unable to show cytolytic activity, but also lost viability. Neuroendocrine differentiation seems to mount less of an immune response when injected in mice, which may contribute to the poor prognosis of cancer patients affected by this pathology.

This study aimed to investigate the impact of short-time hypothyroidism on the expression of aromatase, estrogen receptors (ERα, β), and GPR30 in the pancreas of female rabbits. The formation of new islets and the expression of insulin, GLUT4, and lactate dehydrogenase (LDH) were also analyzed. This purpose is based on actions that thyroid hormones and estrogens have on β-cells differentiation, acinar cell function, and insulin secretion. Twelve Chinchilla-breed adult virgin female rabbits were divided into control (n = 6) and hypothyroid (n = 6; methimazole 10 mg/kg for 30 days) groups. In the complete pancreas, expressions of aromatase and estrogen receptors, as well as proinsulin, GLUT4, and LDH were determined by western blot. Characteristics of islets were measured in slices of the pancreas with immunohistochemistry for insulin. Islet and acinar cells express aromatase, ERα, ERβ, and GPR30. Hypothyroidism increased the expression of ERα and diminished that for aromatase, ERβ, and GPR30 in the pancreas. It also promoted a high number of extra small islets (new islets) and increased the expression of proinsulin and GLUT4 in the pancreas. Our results show that actions of thyroid hormones and estrogens on β-cells neogenesis, acinar cell function, and synthesis and secretion of insulin are linked. Thus, the effects of hypothyroidism on the pancreas could include summatory actions of thyroid hormones plus estrogens. Our findings indicate the importance of monitoring estrogen levels and actions on the pancreas of hypothyroid women, particularly when serum estrogen concentrations are affected such as menopausal, pregnant, and those with contraceptive use.

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.

Oxidative stress and inflammation are involved in the development and/or progression of benign prostatic hyperplasia (BPH). Molecular iodine (I2) induces antiproliferative and apoptotic effects in prostate cancer cells, but it is unknown if I2 regulates oxidative stress in the normal and/or tumoral prostate. The purpose of this study was to analyze the effects of I2 and celecoxib (Cxb) on oxidative stress and inflammation in a model of prostatic hyperplasia. Cxb was used as positive control of cyclooxygenase-2 (COX-2) inhibition. Prostatic hyperplasia was induced in male Wistar rats (170g) with testosterone (5mg/kg/week, for three weeks). One week before hyperplasia induction, I2 (25mg/day/rat) or Cxb (1.25mg/day/rat) was supplied for four weeks in the drinking water. Prostatic hyperplasia was evaluated by histological analysis, DNA content, and/or proliferating cell nuclear antigen (PCNA) expression. Lipoperoxidation (malondialdehyde) and nitrite (NO2-) levels were analyzed by colorimetric methods, while nitric oxide synthase (NOS), COX, and myeloperoxidase (MPO) enzymes were analyzed using RT-PCR, immunoblotting, and/or enzymatic assays. Levels of 15-F2t-isoprostanes, prostaglandins (PGE2), leukotrienes (LTB4), and tumor necrosis factor alpha (TNFα) were measured by ELISA. Control testosterone-treated animals exhibited hyperplasia in the dorsolateral prostate, as well as increments in almost all oxidative parameters except for COX-1, TNFα, or MPO. I2 and Cxb prevented epithelial hyperplasia (DNA content) and oxidative stress induction generated by testosterone in almost the same intensity, and the minimum I2 dose required was 2.5mg/rat. The antioxidant capacity of I2 was also analyzed in a cell-free system, showing that this element inhibited the conversion of nitrate (NO3-) to NO2-. I2 did not modify the prostatic oxidative state in testosterone untreated rats. In summary, our data showed that antiproliferative and antioxidant effects of I2 involve the inhibition of NOS and the COX-2 pathway. Further studies are necessary to analyze the therapeutic and/or adjuvant effects of I2 with first-line medications used to treat BPH.

Pancreatitis and insulitis are known causes of type 2 diabetes mellitus, and recently it has been shown that hypothyroidism can exacerbate these alterations. Molecular iodine (I2) exerts antioxidant, anti-inflammatory, and anti-dyslipidemia effects in diverse tissues. The objective of this study was to evaluate the effect of the oral supplement of this halogen in the induction of prediabetic status in a model of pharmacological hypothyroidism. Adult virgin rabbits of the Chinchilla breed were divided into control (n = 6) and hypothyroid (methimazole, MMI n = 6, 10 mg/kg in drinking water) groups, supplemented with moderate (MMI + I2 0.2 mg/kg; n= 6) and high dose of I2 (MMI + I2 2 mg/kg, n= 6). The results showed that hypothyroidism (1 month) was accompanied by circulating elevations of total cholesterol, HDL, LDL (enzymatic methods) and sCD163 (Western blot). It also promoted pancreatitis (H & E, Masson's trichrome, and PAS stains, as well as western blot for CD163) and insulitis (PAS and Masson's trichrome stains). In the pancreas, hypothyroidism increased the beta-amyloid around vessels (Congo red stain); triglycerides (Folch method), lipoperoxidation (levels of malondialdehyde MDA, enzymatic method) and expression of insulin and GLUT4. A low cholesterol synthesis (Folch method and western blot for CYP51A1) and a decrease in the expression of PPARγ (immunohistochemistry and western blot) were also observed. High doses of I2 supplement (2 mg/kg) aggravated pancreatic damage, promoting even islet amyloidosis and fibrosis. In contrast, the moderate dose of I2 (0.2 mg / kg) was able to prevent alterations in circulating lipids and in the pancreatic tissue. This prevention was accompanied by a significant decrease in the lipoperoxidation and a great expression of PPARγ. These results describe for first time the anti-inflammatory and anti-dyslipidemia effect of the moderate dose of I2 in the pancreas and suggest the possible participation of PPARγ receptors. More studies are needed to analyze the therapeutic effect of iodine in chronic pancreatic diseases associated with inflammation. This work was partially supported by grants CONACyT 257549 and PAPIIT-UNAM 201516.

Epidemiological studies on micronutrient consumption have reported protective associations in the incidence and/or progression of various cancer types. Supplementation with some of these micronutrients has been analyzed, showing chemoprotection, low toxicity, antiproliferation, and the ability to modify epigenetic signatures in various cancer models. The following review inves-tigates the reported effects of micronutrient intake or supplementation in breast cancer progres-sion. A PubMed search was conducted with the keywords “micronutrients breast cancer progres-sion,” and the results were analyzed. The selected micronutrients were: Vitamins (A, C, D, and E), Folic Acid, metals (Cu, Fe, Se, and Zn), fatty acids, polyphenols, and iodine. The majority of in vitro models showed antiproliferative, cell cycle arrest, and antimetastatic effects for almost all the micronutrients analyzed, but these effects do not reflect animal or human studies. Only one clinical trial with Vitamin D and one pilot study with molecular iodine showed favorable overall survival and disease-free interval.

Present work analyzes the tumoral immune response of oral molecular iodine (I2) supplementation with the conventional treatment (5-fluorouracil/epirubicin/ cyclophosphamide or taxotere/epirubicin; FEC/TE) in patients with breast cancer from Hospital General of Queretaro, Mexico. Patients diagnosed with stage II were given placebo (vegetable colored water) or I2 from diagnosis to mastectomy (7 to 40 days) while patients with stage III received placebo or I2 with neoadjuvant FEC/TE treatment (40–70 days). Transcriptomic analysis and GESA studies showed that I2 supplementation alone or in presence of FEC/TE up-regulate Th1 and Th17 differentiation pathways, activation by T-cell receptor, cytotoxicity by NK and CD8+, lymphocyte migration and formation of tertiary lymphoid structures. Deconvolution analysis indicate an increase in macrophages/dendritic cells in I2 group while in FEC/TE+I2 group exhibited increased B cells fractions. Analysis of Th1/Th2 response markers showed significant increase expression in Tbx-21 (RT-PCR) and Interferon gamma (immunohistochemistry) in the FEC/TE+I2 group. This anti-tumor immune activation correlated with the longer disease-free period (43%) and 5 years-survival (60%) observed in FEC/TE+I2 patients. Studies to analyze the effect of I2 supplementation in immunotherapies are in course.

The present work analyzes the antineoplastic effects of molecular iodine alone and in combination with the neoadjuvant therapy FEC/TE (5-fluorouracil/epirubicin/cyclophosphamide or taxotere/epirubicin) in women with breast cancer. In this protocol the immunohistochemistry methodology for the quantification of the estrogen receptor and the proteins associated with the installation of the mesenchymal epithelium transition (e-cadherin and vimentin), immune response (CD8) and cell death (TUNEL) is described, and the methodology for transcriptomic analyses includes: RNA-Seq and transcriptomic analysis; pathway enrichment analysis; validation of the immune response and epithelium/stroma rate and, prediction of the transcription factor regulatory network and peroxisome proliferator-activated receptors type gamma (PPARg) interaction

This study analyzes an oral supplement of molecular iodine (I2), alone and in combination with the neoadjuvant therapy 5-fluorouracil/epirubicin/cyclophosphamide or taxotere/epirubicin (FEC/TE) in women with Early (stage II) and Advanced (stage III) breast cancer. In the Early group, 30 women were treated with I2 (5 mg/day) or placebo (colored water) for 7&ndash, 35 days before surgery. For the Advanced group, 30 patients received I2 or placebo, along with FEC/TE treatment. After surgery, all patients received FEC/TE + I2 for 170 days. I2 supplementation showed a significant attenuation of the side effects and an absence of tumor chemoresistance. The control, I2, FEC/TE, and FEC/TE + I2 groups exhibited response rates of 0, 33%, 73%, and 100%, respectively, and a pathologic complete response of 18%, and 36% in the last two groups. Five-year disease-free survival rate was significantly higher in patients treated with the I2 supplement before and after surgery compared to those receiving the supplement only after surgery (82% versus 46%). I2-treated tumors exhibit less invasive potential, and significant increases in apoptosis, estrogen receptor expression, and immune cell infiltration. Transcriptomic analysis indicated activation of the antitumoral immune response. The results led us to register a phase III clinical trial to analyze chemotherapy + I2 treatment for advanced breast cancer.

Seaweed is an important dietary component and a rich source of iodine in several chemical forms in Asian communities. Their high consumption of this element (25 times higher than in Western countries) has been associated with the low incidence of benign and cancerous breast and prostate disease in Japanese people.We review evidence showing that, in addition to being a component of the thyroid hormone, iodine can be an antioxidant as well as an antiproliferative and differentiation agent that helps to maintain the integrity of several organs with the ability to take up iodine. In animal and human studies, molecular iodine (I2) supplementation exerts a suppressive effect on the development and size of both benign and cancerous neoplasias. Investigations by several groups have demonstrated that these effects can be mediated by a variety of mechanisms and pathways, including direct actions, in which the oxidized iodine dissipates the mitochondrial membrane potential, thereby triggering mitochondrion-mediated apoptosis, and indirect effects through iodolipid formation and the activation of peroxisome proliferator-activated receptors type gamma, which, in turn, trigger apoptotic or differentiation pathways.We propose that the International Council for the Control of Iodine Deficient Disorders recommend that iodine intake be increased to at least 3 mg/day of I2 in specific pathologies to obtain the potential extrathyroidal benefits described in the present review.

One of the most dreaded clinical events for an oncology patient is resistance to treatment. Chemoresistance is a complex phenomenon based on alterations in apoptosis, the cell cycle and drug metabolism, and it correlates with the cancer stem cell phenotype and/or epithelial-mesenchymal transition. Molecular iodine (I2) exerts an antitumor effect on different types of iodine-capturing neoplasms by its oxidant/antioxidant properties and formation of iodolipids. In the present study, wild-type breast carcinoma cells (MCF-7/W) were treated chronically with 10 nM doxorubicin (DOX) to establish a low-dose DOX-resistant mammary cancer model (MCF-7/D). MCF-7/D cells were established after 30 days of treatment when the culture showed a proliferation rate similar to that of MCF-7/W. These DOX-resistant cells also showed increases in p21, Bcl-2 and MDR-1 expression. Supplementation with 200 µM I2 exerted similar effects in both cell lines: it decreased the proliferation rate by ~40%, and I2 co-administration with DOX significantly increased the inhibitory effect (to ~60%) and also increased apoptosis (BAX/Bcl-2 index), principally by inhibiting Bcl-2 expression. The inhibition by I2 + DOX was also accompanied by impaired MDR-1 induction as well as by a significant increase in PPARγ expression. All of these changes could be attributed to enhanced DOX retention and differential down-selection of CD44+/CD24+ and E-cadherin+/vimentin+ subpopulations. I2 + DOX-selected cells showed a weak induction of xenografts in Foxn1nu/nu mice, indicating that the iodine supplements reversed the tumorogenic capacity of the MCF-7/D cells. In conclusion, I2 is able to reduce the drug resistance and invasive capacity of mammary cancer cells exposed to DOX and represents an anti-chemoresistance agent with clinical potential.

TRH synthesized in hypothalamic paraventricular nucleus (PVN) regulates thyroid axis function and is also implicated in anorexigenic effects. Under energy deficit, animals present decreased PVN TRH expression and release, low TSH levels, and increased appetite. Dehydration-induced anorexia (DIA) model allows insight into underlying mechanisms of feeding regulation. Animals drinking a 2.5% NaCl solution for 7 d present body weight reduction; despite their negative energy balance, they avoid food and have increased PVN TRH expression and TSH serum levels. These findings support an inhibiting role of PVN TRH in feeding control. We compared TRH expression by in situ hybridization in PVN subdivisions of 7-d dehydrated male rats to those of a pair-fed group (forced food-restricted) with similar metabolic changes than DIA, but motivated to eat, and to controls. We measured peripheral deiodinase activities, and expression and activity of medial basal hypothalamic type 2 deiodinase and pyroglutamyl-aminopeptidase II, to understand their regulating role in PVN TRH changes between food restriction and anorexia. TRH mRNA levels increased in anterior (aPVN) and medial-caudal subdivisions in DIA rats, whereas it decreased in medial PVN in both experimental groups. We confirmed the nonhypophysiotropic nature of aPVN TRHergic cells by injecting ip fluorogold tracer. Findings support a subspecialization of TRHergic hypophysiotrophic cells that responded differently between anorexic and food-restricted animals; also, that aPVN TRH participates in food intake regulation. Increased type 2 deiodinase activity seemed responsible for low medial PVN TRH synthesis, whereas increased medial basal hypothalamic pyroglutamyl-aminopeptidase II activity in DIA rats might counteract their high TRH release.

BACKGROUND Evidence indicates that iodine per se could be implicated in the physiology of several organs that can internalize it. In thyroid and breast cancer, iodine treatments inhibit cell proliferation and induce apoptosis through a direct (mitochondria) and/or indirect effect (iodolipid generation). Here, we determined the uptake of iodide (I−) and iodine (I2), as well as the antiproliferative and apoptotic effects of 6-iodolactone (6-IL) and both forms of iodine in human prostate cells lines. METHODS Non-cancerous (RWPE-1) and cancerous (LNCaP, DU-145) cells, as well as nude mice xenotransplanted with DU-145 cells were used as cancer models. Iodine uptake was analyzed with radioactive tracers, transporter expression by qRT-PCR, cell proliferation by blue trypan, apoptosis by enzyme immunoassay or fluorescence, BAX and BCL-2 by western-blot, and caspsase 3 by enzymatic assay. RESULTS All three cell lines take up both forms of iodine. In RWPE-1 cells, I− uptake depends on the Na+/I− symporter (NIS), whereas it was independent of NIS in LNCaP and DU-145 cells. Antiproliferative effects of iodine and 6-IL were dose and time dependent; RWPE-1 was most sensitive to I− and 6-IL, whereas LNCaP was more sensitive to I2. In the three cell lines both forms of iodine activated the intrinsic apoptotic pathway (increasing the BAX/BCL-2 index and caspases). Iodine supplementation impaired growth of the DU-145 tumor in nude mice. CONCLUSION Normal and cancerous prostate cells can take up iodine, and depending on the chemical form, it exerts antiproliferative and apoptotic effects both in vitro and in vivo. Prostate 73: 31–41, 2013. © 2012 Wiley Periodicals, Inc.

Peroxisome proliferator-activated receptors (PPAR) are ligand-activated transcription factors. Three subtypes--PPAR alpha, PPAR beta, and PPAR gamma--have been identified and are differentially expressed in tissues. Originally, they were described as molecular regulators of lipid metabolism; recently, it has been shown that they are also involved in regulating the cell cycle and apoptosis in both normal and tumoral cells. In fact, some synthetic PPAR ligands are used to treat dyslipidemia, metabolic diseases, and type 2 diabetes. Here, we review the role of PPAR gamma (PPARγ) in tumor initiation and progression, emphasizing the relationship between this isoform and the cellular and molecular mechanisms involved in the antineoplastic effect of iodine on mammary cancer.

Several groups, including ours, have reported that iodine exhibited antiproliferative and apoptotic effects in various cancer cells only if this element is supplemented as molecular iodine, or as iodide, to cells that are able to oxidize it with the enzyme thyroperoxidase. In this study, we analyzed the effect of various concentrations of iodine and/or iodide in the dimethylbenz[a] anthracene (DMBA) mammary cancer model in rats. The results show that 0.1% iodine or iodide increases the expression of peroxisome proliferator-activated receptor type g (PPARg), triggering caspase-mediated apoptosis pathways in damaged mammary tissue (DMBA-treated mammary gland) as well as in frank mammary tumors, but not in normal mammary gland. DMBA treatment induces the expression of lactoperoxidase, which participates in the antineoplastic effect of iodide and could be involved in the pro-neoplastic effect of estrogens, increasing the formation of DNA adducts. In conclusion, our results show that a supplement of 0.1% molecular iodine/potassium iodide (0.05/0.05%) exert antineoplastic effects, preventing estrogen-induced DNA adducts and inducing apoptosis through PPARg/caspases in pre-cancer and cancerous cells. Since this iodine concentration does not modify the cytology (histology, apoptosis rate) or physiology (triiodothyronine and thyrotropin) of the thyroid gland, we propose that it be considered as an adjuvant treatment for premenopausal mammary cancer. Endocrine-Related Cancer (2011) 18 529‐539

Thyronines are essential for the development of the male reproductive system, including the prostate gland. Metabolically active 3,5,3′ triiodothyronine (T3) is generated mainly by the extrathyroidal, enzymatic 5′deiodination of the prohormone thyroxine (T4), which is catalyzed by deiodinases type 1 (D1) and type 2 (D2). Prostate D1 activity is highly expressed during puberty and declines with age, but continuous, long-term sexual activity prevents this reduction. The aims of this study were to characterize the changes in prostatic D1 activity in response to consecutive ejaculations and to determine whether sympathetic input participates in the local T3 generation (D1 activity). D1 activity was analyzed in prostates of sexually experienced, 4-mo-old male rats after one to five ejaculations. D1 activity, T3 concentrations, and the T3-dependent gene ornithine decarboxylase (Odc) were measured after the fourth ejaculation in prostates of intact, sham, and sympathectomized (Smpx, hypogastric nerve) rats. D1 a...

Mammary cancer is the world's most common malignant neoplasia for women. Recently, the mortality for breast cancer has fallen due principally to early detection and to use of neoadjuvant chemotherapy. Anthracycline antibiotics are the most commonly used anticancer drugs, and Doxorubicin (DOX) is the first choice to treat mammary cancer. Nevertheless, its use has limited by its cadiotoxic side effects, which are generated by free radicals. Our studies in methylnitrosourea (MNU)-induced mammary cancer models have shown that supplementation with moderately high doses of molecular iodine (I2) exhibits two distinctive and beneficial effects: antineoplastic and antioxidant. In the present work we explored these dual characteristic of I2 (0.05%) as an adjuvant to DOX16 (therapeutic dose of 16 mg/kg) and DOX8 (8 mg/kg) in female Sprague Dawley rats (200 g) with tumors induced by a single dose of 50 mg MNU per Kg. Iodine intake is initiated 2 days before DOX application and continues up to sacrifice 7 days later. The following parameters were registered: body weight, tumor size, tumor proliferation rate (proliferating cell nuclear antigen, PCNA), serum creatinine kinase-MB activity (CK-MB), cardiac lipoperoxidation (cLPO), and cardiac catalase activity (cCAT). Values correspond to mean± SD. Different superscripts represent significant (p≥0.05). Tumor reduction was greater in the DOX16 + I2 group than in the DOX 16 group (75% vs. 50%, respectively), and was associated with a significantly greater decrease in the rate of tumor cell proliferation (25% vs 10% decrease in PCNA-positive cells), showing the synergistic effect of I2. In contrast, at both DOX doses, the DOX + I2, groups had lower body weight loss and less cardiac damage (CK-MB; 280% vs 100%, cLPO 100% vs 0%) than with DOX alone. cCAT was not changed by any of the treatments.Conclusions: Iodine acts as an adjuvant by significantly enhancing the antiproliferative effect of DOX at a therapeutic dose (DOX16), and it exerts significant general and cardiac protective effects that do not involve catalase activation. Cellular and molecular mechanisms involved in these dual effects of iodine are currently being analyzed. The authors thank Drs. Mauricio Diaz, Marcela Lizano, and Brenda Anguiano as well as Biol. Felipe Ortiz for their technical assistance and Leonor Casanova for academic supports. We also thank Dr. Dorothy Pless for proof-reading. Supported in part by PAPIIT/UNAM 201210 and CONACYT 78955 and 47928/47928. Figure available in online version. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-10-16.

Several laboratories including ours have shown that iodine (I2) intake exhibits potent antiproliferative and apoptotic effects in vivo and in vitro models of mammary cancer. Molecular analysis of these effects indicates that antioxidant; cellular arrest and apoptotic pathways are involved. As the cellular mechanism that triggers these antineoplastic effects we have proposed that I2 could act in 2 possible ways, directly as antioxidant or indirectly by generating an iodinated arachidonic acid (6-iodoloctone) which exhibits apoptotic effects and is a specific ligand of proliferative peroxisome activated receptor gamma (PPARg). In previous preliminary reports, we corroborated an antiproliferative I2 effect (decreased PCNA) in premenopausal (pre-M) and an apoptotic action (triggering the Bax-Caspase pathway) in both pre-M and post menopausal (post-M) women with early stage breast cancer. In the present report we raise the casuistic and deeply in the analysis of mechanisms involved in this antineoplastic effect of I2. This study includes 22 women (average age 52.9 ± 12.6) diagnosed with early stage breast cancer (IIa and IIb). Patients were divided according to hormonal status into pre-M and post-M groups and were supplemented with I2 (5 mg daily) or placebo (vegetable dye) for2-5 weeks before surgery. Thyroid status (T3 and TSH; RIA) and iodine intake (urine, HPLC) were analyzed. In biopsies (beginning) and/or tumors (final), the level and location (cytosol or nuclear) of estrogen receptor alfa (ERα) and beta (ERb) were analyzed by immunohistochemistry. In tumors, we measured PPARg expression, invasive potential [hypoxia-inducible factor (HIF) and vascular endothelial growth factor (VEGF) by real time PCR] and fibrosis content (Masson's trichromic method). The results show that I2 supplementation in pre-M women is accompanied by a significant increase in the concentration of total ERα and PPARg and no change in total ERb; however, the fraction of ERα in the nucleus was significant lower, and the fibrosis content was higher (70%) than in the placebo group (40%). In contrast, I2 supplements significantly decreased HIF and VEGF expression in both pre-and post-M women. In conclusion, our data show that, in addition to the apoptotic and anti-invasive effects on mammary cancer exhibited by I2 that are independent of hormonal status, in pre-M women, I2 also acts to diminish the effects of estrogen (decreases nuclear translocation of ERα). Experiments that analyze the possible role of PPARg in these actions are in progress. We thank Dr. Jorge Alvarez-Aguirre2,3, Dr. Alonso Gallegos-Corona2, Lic. Concepción Correa-Tinajero3, Alejandro Nuñez-Nolasco2,3, Dra. Norma Uribe Uribe4, Jaime Ayala García4 and Dr. Dorothy Pless1. This work was supported by in part by PAPIIT-UNAM IN201210 and CONACyT 78955 and 85952. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-14-15.

Consumption of fruits and vegetables has been associated with reduced risk of chronic diseases. They are rich in several antioxidant phytochemicals such as carotenoids and phenolic compounds that could be responsible for the health benefits. We studied the antineoplastic properties of some fruits and vegetables using in vivo and in vitro models. First, we studied the effect of ‘Ataulfo’ mango consumption on chemically-induced mammary carcinogenesis and plasma antioxidant capacity (AC) in rats treated with the carcinogen N-methyl-Nnitrosourea (MNU). Mango was administered in the drinking water (0.02-0.06 g/ml) during both short-term and long-term periods to rats, and plasma antioxidant capacity was measured by ferric reducing/antioxidant power (FRAP) and total oxyradical scavenging capacity assays. Mango consumption did not have an effect on mammary carcinogenesis (incidence, latency and number of tumors), nor on plasma AC of rats treated with MNU. Second, we screened using methylthiazolydiphenyltetrazolium bromide assay the antiproliferative activity of aqueous extracts of avocado, black sapote, guava, mango, cactus cladodes (cooked and raw), papaya, pineapple, four different prickly pear fruit, grapes and tomato, on the breast cancer cell line MCF-7. β-carotene, gallic acid, total phenolic contents and AC were analyzed in each aqueous extract. In vitro study showed that only the papaya extract had a significant antiproliferative effect and we did not notice a relationship between total phenolic content and AC with antiproliferative effect. These results suggested that each plant food has a unique combination in quantity and quality of phytochemicals which could determine its biological activity.

BACKGROUND Thyroxine (T4) and triiodothyronine (T3) are involved in the development and function of the male reproductive system. The type 1 deiodinase enzyme (D1) plays a major role in the intracellular conversion of T4 to the active form, T3. D1 is expressed in the prostate of pubescent rats, but it is unknown whether locally generated T3 is involved in the development and function of this gland. METHODS D1 activity was analyzed in prostates from neonatal to old rats. Local T3 generation (D1 and T3 levels) was evaluated in adult animals with 1–5 months of continuous sexual activity. D1 activity was measured by the radiolabeled-iodide-release method and T3 concentration by radioimmunoassay. Secretory activity of the prostate was evaluated by a morphological analysis of epithelium (hematoxilin-eosin stain) and by measuring the activity of acid phosphatase as a marker enzyme for secretion. RESULTS The highest prostate D1 activity was expressed around puberty, and it was almost undetectable during the neonatal period and with aging. Interestingly, 1 and 4 months of sexual activity avoided the decrease of D1 activity associated with aging. Sexual activity provoked a hypertrophy and functional hyperplasia in all lobes, but D1 and acid phosphatase activity increased only in the ventral lobe. D1 activity correlated with an increase in the prostatic T3 concentration. CONCLUSIONS The increased local generation of T3 in prostate might be related to: (1) the differentiation/maturation that occurs at puberty and (2) the energy expenditure associated with maintaining the secretory activity of the glandular epithelium. Prostate 69: 1651–1659, 2009. © 2009 Wiley-Liss, Inc.

We analyzed the participation of N-methyl-d-aspartate (NMDA) receptors in the neuronal damage caused by adult-onset hypothyroidism. Wistar rats were randomly assigned into four groups. The euthyroid group received tap water. The hypothyroid group received methimazole (60 mg/kg) in their drinking water to induce hypothyroidism. Two more groups of rats received the antithyroid treatment and were injected daily with the NMDA antagonist ketamine (15 mg/kg, sc) or MK-801 (0.5mg/kg, ip). Treatments were administered during 4 weeks. At the end of the respective treatments rats were deeply anaesthetized and perfused intracardially with 0.9% NaCl followed by 4% paraformaldehyde. The brains were removed from the skull, and coronal brain sections (7microm thick) were obtained. Neurons were counted in the CA1, CA2, CA3, and CA4 hippocampal regions differentiating between normal and atrophic cells by an experimenter blind to the treatment. The percentage of neuronal damage found in the MMI group was significantly greater in the hippocampal regions compared to the euthyroid group. In contrast, both NMDA antagonists were able to prevent the neuronal damage secondary to hypothyroidism in all hippocampal regions. Our results suggest that the neuronal damage caused in the hippocampus of adult-onset hypothyroid rats requires activation of NMDA channels.

Previous reports have documented the antiproliferative properties of I(2) and the arachidonic acid (AA) derivative 6-iodolactone (6-IL) in both thyroid and mammary glands. In this study, we characterized the cellular pathways activated by these molecules and their effects on cell cycle arrest and apoptosis in normal (MCF-12F) and cancerous (MCF-7) breast cells. Low-to-moderate concentrations of I(2) (10-20 microM) cause G1 and G2/M phase arrest in MCF-12F and caspase-dependent apoptosis in MCF-7 cells. In normal cells, only high doses of I(2) (40 microM) induced apoptosis, and this effect was mediated by poly (ADP-ribose) polymerase-1 (PARP1) and the apoptosis-induced factor, suggesting an oxidative influence of iodine at high concentrations. Our data indicate that both I(2) and 6-IL trigger the same intracellular pathways and suggest that the antineoplasic effect of I(2) in mammary cancer involves the intracellular formation of 6-IL. Mammary cancer cells are known to contain high concentrations of AA, which might explain why I(2) exerts apoptotic effects at lower concentrations only in tumoral cells.

We characterized the enzymes that catalyze the deiodination of T4 to T3 in the male reproductive tract. Testis, epididymis (EPI), seminal vesicles, prostate, bulbourethral glands, spermatozoa, and semen were taken from sexually mature rats (300 g). Iodothyronine 5′-deiodinase (5′-D) activity was quantified by the radiolabeled-iodide-release method. 5′-D activity was 10-fold higher in EPI and semen than in the rest of the tissues. In EPI, semen, and prostate, the enzymatic activity was completely inhibited by 1 mm 6-n-propyl-2-thiouracil, whereas in the other tissues the inhibition was partial (50%). The high susceptibility to 6-n-propyl-2-thiouracil inhibition, a ping-pong kinetic pattern, and low cofactor (Michaelis Menten constant for dithiothreitol = 0.7 mm) and high substrate (Michaelis Menten constant for reverse T3 = 0.4 μm) requirements indicate that EPI 5′-D corresponds to type 1 deiodinase (D1). Real-time RT-PCR amplification of D1 mRNA in this tissue confirms this conclusion. The highest EPI D1 expression occurred at the onset of puberty and sexual maturity, and in the adult, this activity was more abundant in corpus and caput than in the caudal region. EPI D1 expression was elevated under conditions of hyperthyroidism and with addition of 17β-estradiol. Our data also showed a direct association between D1 and a functional epididymis marker, the neutral α-glucosidase enzyme, suggesting that local generation of T3 could be associated with the development and function of EPI and/or spermatozoa maturation. Further studies are necessary to analyze the possible physiological relevance of 5′-D in the male reproductive system.

Shock waves are known to permeabilize eukaryotic cell membranes, which may be a powerful tool for a variety of drug delivery applications. However, the mechanisms involved in shock wave-mediated membrane permeabilization are still poorly understood. In this study, the effects on both the permeability and the ultrastructural features of two human cell lineages were investigated after the application of underwater shock waves in vitro. Scanning Electron Microscopy of cells derived from a human embryo kidney (HEK)-293 and Michigan Cancer Foundation (MCF)-7 cells, an immortalized culture derived from human breast adenocarcinoma, showed a small amount of microvilli (as compared to control cells), the presence of hole-like structures, and a decrease in cell size after shock wave exposure. Interestingly, these effects were accompanied by the permeabilization of acid and macromolecular dyes and gene transfection. Trypan blue exclusion assays indicated that cell membranes were porated during shock wave treatment but resealed after a few seconds. Deformations of the cell membrane lasted for at least 5 min, allowing their observation in fixed cells. For each cell line, different shock wave parameters were needed to achieve cell membrane poration. This difference was correlated to successful gene transfection by shock waves. Our results demonstrate, for the first time, that shock waves induce transient micro- and submicrosized deformations at the cell membrane, leading to cell transfection and cell survival. They also indicate that ultrastructural analyses of cell surfaces may constitute a useful way to match the use of shock waves to different cells and settings.

Purpose: In addition to being a component of thyroid hormone (TH), iodine can be an antioxidant as well as an antiproliferative and differentiation agent that helps to maintain the integrity of several organs with the ability to take up iodine.Methods and Results: Studies from our laboratory shown that in preclinical (cell culture, induced animal cancer and xenographs) and clinical studies (mammary cancer protocol), molecular iodine (I2) supplementation exerts suppressive effects on implantation, development, and progression of cancer neoplasias. These effects can be mediated by a variety of mechanisms and pathways, including direct actions, in which the oxidized iodine modulates the immune/tumor response and through iodolipid formation and the activation of peroxisome proliferator-activated receptors type gamma (PPARγ) triggering apoptotic and/or differentiation pathways.Conclusion: The absence of side effects and the easy availability and handling of I2 have allowed the establishment of clinical protocols to utilize I2 supplementation as an adjuvant in therapies against cancers that take up iodine.-----------------------------------------Cite this article as: Aceves C, Anguiano B. Antineoplastic mechanisms of Iodine in cancers that take up Iodine. Int J Cancer Ther Oncol 2015; 3(4):3401.[This abstract was presented at the BIT’s 8th Annual World Cancer Congress, which was held from May 15-17, 2015 in Beijing, China.]

We analyzed the effect of molecular iodine (I2), potassium iodide (KI) and a subclinical concentration of thyroxine (T4) on the induction and promotion of mammary cancer induced by N-methyl-N-nitrosourea. Virgin Sprague-Dawley rats received short or continuous treatment. Continuous I2 treated rats exhibited a strong and persistent reduction in mammary cancer incidence (30%) compared to controls (72.7%). Interruption of short or long term treatments resulted in a higher incidence in mammary cancer compared to the control groups. The protective effect of I2 was correlated with the highest expression of the I-/Cl- transporter pendrin and with the lowest levels of lipoperoxidation expression in mammary glands. Triiodothyronine serum levels and Na+/I- symporter, lactoperoxidase, or p53 expression did not show any changes. In conclusion continuous I2 treatment has a potent antineoplastic effect on the progression of mammary cancer and its effect may be related to a decrease in the oxidative cell environment.

Peripartum is a crucial period for mammary gland final differentiation and the onset of lactation. Although the ‘trigger’ for lactogenesis depends on several hormones, a key factor is the peripartum prolactin (PRL) pulse whose deletion results in a failure to initiate milk production. Other hormones having a critical role during this period but exerting a contrary effect are the thyronines. A transitory hypothyroidism occurs at peripartum in serum and several other extrathyroidal tissues, whereas the induction of hyperthyroidism during late pregnancy is associated with the absence of lactation after delivery. We analyzed the mammary gland during pregnancy and lactation for: (a) the type and amount of thyroid receptors (TRs), (b) the local triiodothyronine (T3) generation catalyzed by type I deiodinase (Dio1), (c) the Dio1 response to norepinephrine (NE) and (d) the effect on Dio1 and TRs of blocking the PRL pulse at peripartum. Our data showed that during pregnancy the mammary gland contains Dio1 in low amounts associated with the highest expression of TRα1; whereas during lactation the gland shows high levels of both Dio1 and TRα1. However, at peripartum, both TRs and Dio1 decrease, and Dio1 becomes refractory to NE. This refractoriness disappears when the PRL pulse is blocked by the dopamine agonist bromocriptine. This blockade is also accompanied by a significant decrease in cyclin D1 expression. Our data suggested that the peripartum PRL pulse is part of a protective mechanism against precocious differentiation and/or premature involution of the alveolar epithelium due to T3 overexposure.

Streptococcus mutans is a pathogen related to the occurrence of human dental caries. The determination of total amounts of mutans streptococci, as well as the proportion related to other oral bacteria, is of interest when assessing the risk of developing caries. In this context, it is better to use a sensitive, specific and non-time consuming method such as the polymerase chain reaction (PCR), than to use culture and biochemical identification methods. In this work we identified potentially cariogenic strains of S. mutans and assessed the relationship with the dmft, DMFT or dmft/DMFT index. Using DNA isolated from dental plaque, a 192 bp sequence was identified and amplified from the spaP gene and a 722 bp sequence from the dexA gene. The results suggest that it is important to evaluate the presence of cariogenic S. mutans strains in plaque content rather than the accumulation of plaque itself. However, other factors like diet, hygiene, genetic background, the flow rate of saliva and the presence of specific antibodies, also play a key role in the development of caries.

Thyroid hormones participate in the regulation of growth, development and energy expenditure of vertebrates. Type I (D1) and type II 5'deiodinases catalyze the peripheral conversion of the thyroid prohormone thyroxine to the active form triiodothyronine (T3). D1 is expressed in organs like liver, thyroid, and lactating mammary gland. This enzyme is regulated in an organ-specific manner by a wide number of factors like carbohydrates, T3, thyrotropin, and catecholamines. However, it has been shown that in several types of cancer the expression of D1 is reduced, lost, or regulated by different components. In the present work we describe the expression and regulation of 5'deiodinases in two breast cancer cell lines: MCF-7 (ovarian hormone-dependent) and MDA-MB-231 (ovarian hormone-independent). Our results showed that MCF-7 cells expressed D1 activity ( approximately 10 pmol I(-)/mg protein per h), which was stimulated only by retinoic acid treatments, but not by T3 or the beta-adrenergic agonist isoproterenol. In MDA-MB-231 cells, deiodinase activity was not detected in control conditions nor under any of these treatments. These results support the notion that D1 expression could represent a sensitive differentiation marker.

An iodinated derivative of arachidonic acid, 5-hydroxy-6-iodo-8,11,14-eicosatrienoic acid, δ-lactone (6-IL) has been implicated as a possible intermediate in the autoregulation of the thyroid gland by iodine. In addition to antiproliferative and apoptotic effects observed in thyrocytes, this iodolipid could also exert similar actions in cells derived from extrathyroidal tissues like mammary gland, prostate, colon, or the nervous system. In mammary cancer (solid tumors or tumor cell lines), 6-IL has been detected after molecular iodine (I 2 ) supplement, and is a potent activator of peroxisome proliferator-activated receptor type gamma (PPARγ). These observations led us to propose I 2 supplement as a novel coadjutant therapy which, by inducing differentiation mechanisms, decreases tumor progression and prevents chemoresistance. Some kinds of tumoral cells, in contrast to normal cells, contain high concentrations of arachidonic acid, making the I 2 supplement a potential “magic bullet” that enables local, specific production of 6-IL, which then exerts antineoplastic actions with minimal deleterious effects on normal tissues.

Hypothyroidism affects neuron population dynamics in the hippocampus of the adult rat, with neuronal damage as the main feature of its effect. This effect is prevented by the blockade of NMDA receptors, which suggests that glutamatergic activity mediates cell death in this condition. Glutamate can also stimulate cell proliferation and survival of newborn neurons, indicating that it can affect different stages of the cell cycle. In this work we measured the expression of specific proteins that control cell proliferation (cycline-D1), cell arrest (p21), damage (p53) or apoptosis (Bax and Bcl2) in the hippocampus of hypothyroid rats treated with the NMDA receptor (NMDAR) blocker MK-801 during the induction of hypothyroidism. The results show that hypothyroidism increases the expression of markers of DNA damage, cell arrest, and apoptosis, but does not affect the marker of cell proliferation. NMDAR blockade prevents the increase on markers of DNA damage and apoptosis, but does not influence cell arrest or cell proliferation. This suggests that hypothyroidism promotes cell death mainly by an excitotoxic effect of glutamate.