Revisit dietary fiber on colorectal cancer: butyrate and its role on prevention and treatment.

Colorectal cancer is still a major health problem worldwide. Based on the most recent released data by the World Health Organization GLOBOCAN in 2012, colorectal cancer is the third most prevalent type of cancer in males and the second in females. In 1999, it was published the first report showing evidence of a strong correlation between diet and cancer incidence, being its positive or negative impact intimately linked to dietary patterns. A diet rich in fiber is associated with a low risk of developing colorectal cancer. The fermentation of the dietary fiber by intestinal microflora results in production of butyrate, which plays a plurifunctional role on the colonocytes, and it has also been reported as a chemopreventive agent. However, there are limited studies focusing its anti-cancer potential. Here, we review the recent new insights that focus butyrate and its role in colorectal cancer prevention and treatment, from its synthesis, metabolism, and transport, through its involvement on several cancer-related signaling pathways, to the novel existing approaches for its clinical use.

Lung cancer: the immune system and radiation.

Lung cancer has a known relationship with smoking and is one of the leading causes of cancer-related death worldwide. Although the number of studies discussing lung cancer is vast, treatment efficacy is still suboptimal due to the wide range of factors that affect patient outcome. This review aims to collect information on lung cancer treatment, specially focused on radiation therapy. It also compiles information regarding the influence of radiotherapy on the immune system and its response to tumour cells. It evaluates how immune cells react after radiation exposure and the influence of their cytokines in the tumour microenvironment. The literature analysis points out that the immune system is a very promising field of investigation regarding prognosis, mostly because the stromal microenvironment in the tumour can provide some information about what can succeed in the future concerning treatment choices and perspectives. T cells (CD4+ and CD8+), interleukin-8, vascular endothelial growth factor and transforming growth factor-ß seem to have a key role in the immune response after radiation exposure. The lack of large scale studies means there is no common consensus in the scientific community about the role of the immune system in lung cancer patients treated with radiotherapy. Clarification of the mechanism behind the immune response after radiation can lead to better treatments and better quality life for patients.

Effect of amniotic membrane proteins in human cancer cell lines: an exploratory study.

Human amniotic membrane (hAM) has recently drawn attention as an upcoming anti-cancer therapy. Regarding the strategies which have already investigated, little is known about hAM protein extracts (hAMPE) effect on cancer. So, this work aims to study the effect of hAMPE in metabolic activity of several human cancer cell lines. hAMPE were mechanically obtained, thus avoiding the effect of detergents and other reagents commonly used in protein extraction under the cell lines studied. After quantification of proteins in hAMPE, their effect on the metabolic activity of 21 human cancer cell lines was assessed by 3-(4,5-dimethylthia-zolyl-2)2,5-diphenyltetrazolium bromide (MTT) assay. Our results indicate that there is an inhibition of metabolic activity until 25 and 50% in two and seven cell lines, respectively. Five cell lines proved to be very sensitive to hAMPE, being its metabolic activity more than 50% inhibited. Our results show that hAMPE can inhibit the metabolic activity of some human cancer cell lines. However, research about this cell line-dependent response to hAMPE becomes indispensable.

Amniotic membrane: from structure and functions to clinical applications.

Amniotic membrane (AM) or amnion is a thin membrane on the inner side of the fetal placenta; it completely surrounds the embryo and delimits the amniotic cavity, which is filled by amniotic liquid. In recent years, the structure and function of the amnion have been investigated, particularly the pluripotent properties of AM cells, which are an attractive source for tissue transplantation. AM has anti-inflammatory, anti-bacterial, anti-viral and immunological characteristics, as well as anti-angiogenic and pro-apoptotic features. AM is a promoter of epithelialization and is a non-tumorigenic tissue and its use has no ethical problems. Because of its attractive properties, AM has been applied in several surgical procedures related to ocular surface reconstruction and the genito-urinary tract, skin, head and neck, among others. So far, the best known and most auspicious applications of AM are ocular surface reconstruction, skin applications and tissue engineering. However, AM can also be applied in oncology. In this area, AM can prevent the delivery of nutrients and oxygen to cancer cells and consequently interfere with tumour angiogenesis, growth and metastasis.

Hepatocellular carcinoma and chemotherapy: the role of p53.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most common primary neoplasm of the liver. A major proportion of HCCs also present mutation of the gene that encodes p53, which confers chemoresistance. The main goal of this work is to investigate the effect of cisplatin, doxorubicin and 5-fluoruracil (5-FU) in three human HCC cell lines which differ in p53 expression. METHODS: HepG2 (expressing normal p53), HuH7 (expressing mutated p53) and Hep3B2.1-7 (not expressing p53) cell lines were cultivated in the presence of cisplatin, doxorubicin and 5-FU. Cell proliferation was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT assay). The type of cell death and Bax and Bcl2 activation were assessed by flow cytometry. RESULTS: It was found that for all of the cell lines studied, the agent that gave the most satisfactory results was doxorubicin. 5-FU demonstrated no activity in these cell lines. CONCLUSIONS: For all the cell lines studied, doxorubicin was the most satisfactory agent. In HepG2 and HuH7 cell lines, it can activate Bax with statistical significance.

Elevated soluble TNFα levels and upregulated TNFα mRNA expression in purified peripheral blood monocyte subsets associated with high-grade hepatocellular carcinoma.

BACKGROUND: Chronic inflammation is involved in the initiation and progression of various cancers, including liver cancer. The current study focuses on the characterization of the peripheral immune response in hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) patients, before and after surgical procedure, in order to assess the effect of tumor resection in the immune system homeostasis and to determine possible prognostic factors associated with high-grade tumors. We developed a whole-blood assay to monitor immune alterations and functional competence of peripheral monocytes in a group of 10 healthy individuals (HG), in 20 HCC patients and 8 CCA patients, by multi-color flow cytometry, qRT-PCR, and ELISA techniques. RESULTS: The qRT-PCR analysis showed an upregulation of TNFα expression by classical and intermediate monocytes purified from HCC patients presenting tumors in grade G3-G4 as compared to G1-G2 HCC patients. Moreover, ELISA assay confirmed elevated serum levels of TNFα in G3-G4 compared to G1-G2 HCC patients. A significant decrease of circulating non-classical monocytes was detected in both CCA and HCC patients before and after surgical procedure. In addition, a functional defect in circulating classical and intermediate monocytes was observed in both groups of cancer patients when compared to the HG, with partial recovery after the surgical intervention. CONCLUSIONS: This integrated analysis permitted the identification of altered functional competence of monocyte subsets in CCA and HCC patients. In addition, our results point to a potential role of TNFα as a prognostic peripheral biomarker in HCC patients, indicating the presence of high-grade tumors that should be further validated.

Functional and Phenotypic Characterization of Tumor-Infiltrating Leukocyte Subsets and Their Contribution to the Pathogenesis of Hepatocellular Carcinoma and Cholangiocarcinoma.

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) represent the most common primary liver malignancies whose outcome is influenced by the immune response. In the present study, we evaluated the tumor-infiltrating leukocyte (TIL) populations in 21 HCC patients and 8 CCA patients by flow cytometry immediately after the surgical procedure. Moreover, CD4+ T cells, CD8+ T cells, monocytes, and macrophages were purified by cell sorting for further analysis of gene expression by quantitative reverse-transcription polymerase chain reaction. Regarding tumor-infiltrating macrophages, we observed a significantly higher expression of markers associated with M2 phenotype and a higher expression of PD-L1 in patients with HCC in comparison to CCA. In addition, for HCC patients, we found a significant increase in the expression of CD200R in macrophages from tumors that were in grade G3-G4 as compared to tumors in grade G1-G2. Besides, a significantly higher frequency of tumor-infiltrating lymphocytes, CD8+CD56+ T cells, and natural killer cells was detected in HCC biopsies in comparison to CCA. In summary, this study has revealed functional and phenotypic differences in TIL cell subpopulations between CCA and HCC, as well as among different histopathological grades and tumor aggressiveness degrees, and it has provided evidence to better understand the tumor immune microenvironment of CCA and HCC.

Glycolysis Inhibition as a Strategy for Hepatocellular Carcinoma Treatment?

Hepatocellular carcinoma (HCC) is the most frequently detected primary malignant liver tumor, representing a worldwide public health problem due to its high morbidity and mortality rates. The HCC is commonly detected in advanced stage, precluding the use of treatments with curative intent. For this reason, it is crucial to find effective therapies for HCC. Cancer cells have a high dependence of glycolysis for ATP production, especially under hypoxic environment. Such dependence provides a reliable possible strategy to specifically target cancer cells based on the inhibition of glycolysis. HCC, such as other cancer types, presents a clinically well-known upregulation of several glycolytic key enzymes and proteins, including glucose transporters particularly glucose transporter 1 (GLUT1). Such enzymes and proteins constitute potential targets for therapy. Indeed, for some of these targets, several inhibitors were already reported, such as 2-Deoxyglucose, Imatinib or Flavonoids. Although the inhibition of glycolysis presents a great potential for an anticancer therapy, the development of glycolytic inhibitors as a new class of anticancer agents needs to be more explored. Herein, we propose to summarize, discuss and present an overview on the different approaches to inhibit the glycolytic metabolism in cancer cells, which may be very effective in the treatment of HCC.

Halogen atom effect on photophysical and photodynamic characteristics of derivatives of 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin.

Brominated and iodinated derivatives of 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin were synthesised directly from the corresponding aldehydes. Photophysical and photochemical properties, singlet oxygen formation quantum yields, photobleaching and log P were measured. Cellular uptake measurements and cytotoxicity assays on WiDr and A375 tumour cell lines were performed. 5,10,15,20-Tetrakis(2-bromo-5-hydroxyphenyl)porphyrin showed the best cytotoxicity with values of IC(50) of 113 nM over WiDr cells and 52nM over A375 cells.

Targeted alpha therapy using Radium-223: From physics to biological effects.

With the advance of the use of ionizing radiation in therapy, targeted alpha therapy (TAT) has assumed an important role around the world. This kind of therapy can potentially reduce side effects caused by radiation in normal tissues and increased destructive radiobiological effects in tumor cells. However, in many countries, the use of this therapy is still in a pioneering phase. Radium-223 (223Ra), an alpha-emitting radionuclide, has been the first of its kind to be approved for the treatment of bone metastasis in metastatic castration-resistant prostate cancer. Nevertheless, the interaction mechanism and the direct effects of this radiopharmaceutical in tumor cells are not fully understood neither characterized at a molecular level. In fact, the ways how TAT is linked to radiobiological effects in cancer is not yet revised. Therefore, this review introduces some physical properties of TAT that leads to biological effects and links this information to the hallmarks of cancer. The authors also collected the studies developed with 223Ra to correlate with the three categories reviewed - properties of TAT, 5 R's of radiobiology and hallmarks of cancer- and with the promising future to this radiopharmaceutical.

Oxidative Stress, DNA, Cell Cycle/Cell Cycle Associated Proteins and Multidrug Resistance Proteins: Targets of Human Amniotic Membrane in Hepatocellular Carcinoma.

The anticancer effects of human amniotic membrane (hAM) have been studied over the last decade. However, the action mechanisms responsible for these effects are not fully understood until now. Previously results reported by our team proved that hAM is able to induce cytotoxicity and cell death in hepatocellular carcinoma (HCC), a worldwide high incident and mortal cancer. Therefore, this experimental study aimed to investigate the cellular targets of hAM protein extracts (hAMPE) in HCC through in vitro studies. Our results showed that hAMPE is able to modify oxidative stress environment in all HCC cell lines, as well as its cell cycle. hAMPE differently targets deoxyribonucleic acid (DNA), P21, P53, ß-catenin and multidrug resistance (MDR) proteins in HCC cell lines. In conclusion, hAMPE has several targets in HCC, being clear that the success of this treatment depends of a personalized therapy based on the biological and genetic characteristics of the tumor.

Selective cytotoxicity and cell death induced by human amniotic membrane in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) has a worldwide high incidence and mortality. For this reason, it is essential to invest in new therapies for this type of cancer. Our team already proved that human amniotic membrane (hAM) is able to inhibit the metabolic activity of several human cancer cell lines, including HCC cell lines. Taking into account the previously performed work, this experimental study aimed to investigate the pathways by which hAM protein extracts (hAMPEs) act on HCC. Our results showed that hAMPE reduce the metabolic activity, protein content and DNA content in a dose- and time-dependent manner in all HCC cell lines. This therapy presents selective cytotoxicity, since it was not able to inhibit a non-tumorigenic human cell line. In addition, hAMPE induced cell morphology alterations in all HCC cell lines, but death type is cell line dependent, as proved by in vitro and in vivo studies. In conclusion, hAMPE have a promising role in HCC therapy, since it is capable of inducing HCC cytotoxicity and cell death.

Evaluation of pulmonary systemic blood flow using ECG gated acquisition.

We propose a functional parametric analysis method using ECG-gated 99mTc-labeled red blood cell (RBC) imaging for detection and characterization of periodic variations in local blood activity in the lungs during cardiac cycle. We validated in animal experiments that such count variations correlate with cyclical pulmonary blood flow and may be used for evaluation of systemic-to-pulmonary shunts. Clinical studies were performed in 48 patients. After labeling the RBC pool with 99mTc, ECG-gated gamma camera images of both lung fields were acquired and processed to obtain Fourier transforms of time/activity functions in selected regions. The first harmonic parametric images of amplitude and phase were derived. There was an excellent correlation (r = 0.92) between activity variations and pulsatile flow measured by our method with that obtained by the thermodilution method in dog experiments (n = 10) after implantation of a systemic-to-pulmonary shunt. Patient studies showed the technique to be sensitive in detecting and quantifying abnormal systemic-to-pulmonary blood flow. Lung pulsatile flow can thus be noninvasively measured from functional parametric phase and amplitude images; the technique may be useful for detecting and quantifying abnormal systemic-to-pulmonary blood flow in man.

Cardiac lymphatic dynamics after ischemia and reperfusion--experimental model.

ABSTRACT. The aim of the present study was to investigate the lymphatic cardiac circulation in an experimental model of ischemia plus reperfusion in mongrel dogs (Canis familiaris L). As radiotracer we used 0.2-0.25 ml (111 MBq) of 99mTc-Re2S7 colloid (+/-10 microm), injected subcapsullary below the second diagonal of the descending anterior ligated coronary artery with a special needle. A gamma-camera/Starport + DecStation were used for data acquisition. Four experimental groups with five animals each were established: G I = controls; G II = immediately after acute myocardial infarction (AMI); G III = late infarction (5 days after AMI); G IV = ischemia (90 min) + reperfusion. Four regions of interest (ROIs) were chosen: injection area (ZA), above (ZB), near right (ZD), and far right (ZC) from ZA. Mean disappearance times in ZA and dynamic parameters in the other ROIs were determined from activity/time curves drawn in each area, using homemade software. The results obtained seem to indicate that the methodology is appropriate to a detailed study of lymphatic drainage in pathological situations in animal models.

Lymphatic uptake of pulmonary delivered radiolabelled solid lipid nanoparticles.

UNLABELLED: Lymphatic drainage plays an important role in the uptake of particulates in the respiratory system, being also associated to the spreading of lung cancer through metastasis development. In recent years solid lipid nanoparticles (SLN) have been proposed as carriers of anti-tumoural drugs, for their low toxicity and surface characteristics make them suitable for either imaging (gamma-scintigraphy) or therapy upon encapsulation of cytotoxic drugs. Assessment of inhaled radiolabelled SLN biodistribution is described in the present work. METHODS: Nanoparticles (200 nm) were radiolabelled with 99mTc using the lipophilic chelator D,L-hexamehylpropyleneamine oxime (HMPAO). Biodistribution studies were carried out following aerosolisation and administration of a 99mTc-HMPAO-SLN suspension to a group of adult male Wistar rats. A 60 min dynamic image acquisition was performed in a gamma-camera, followed by static image collection at 30 min intervals up to 4 h postinhalation. Radiation counting was performed in organ samples, collected after the animals were sacrificed. RESULTS: The data show an important and significant uptake of the radiolabelled SLN into the lymphatics after inhalation, and a high rate of distribution in periaortic, axillar and inguinal lymph nodes. CONCLUSION: Results indicate that SLN could be effective colloidal carriers for lymphoscintigraphy or therapy upon pulmonary delivery.

First pass evaluation of blood velocity in the pulmonary artery.

Studying the kinetics of blood flow in the pulmonary artery using non-invasive techniques may be an important tool in assessing the prognosis of lung diseases. The aim of this study was to ascertain dynamic parameters of pulmonary blood flow, particularly the velocity of a small bolus of a radioactive tracer after intravenous injection. Since the shape and distribution pattern of the bolus changes substantially from frame to frame, common image processing techniques for motion detection or other techniques, such as accumulation of subtracted images, segmentation and spectral analysis with temporal/spatial filtering, are unable to properly evaluate the motion of the bolus. However, the passage of the bolus from the arm to the lungs was visualized with good contrast through acquisition of a first pass sequence of scintigraphic images. The wave form of the bolus becomes increasingly complex as it progresses towards the pulmonary artery. In the proposed method the time-activity curves for each pixel are displayed. It is assumed that the peaks of the maximum counts in these curves correlate with the time after injection that the bolus takes to cross each pixel (bolus head). The bolus head contains information on time, space and activity, and allows the velocity of the studied fluid to be calculated. We demonstrated a mean velocity through the pulmonary artery trunk in resting patients of approximately 11 cm/s, with a mean residence time of 0.5 s.

Evaluation of the alveolar-capillary membrane permeability using 99mTc-HMPAO aerosols in severe diffuse interstitial fibrosis.

Local information on permeability of the alveolar-capillary barrier (PACB) can be ascertained by parametric images, after inhalation of radioarosols and computer processing. Our aim is to compare the results of 99mTc-HMPAO aerosols on PACB studies with those of 99mTc-DTPA aerosols, a standard technique. We compared the two techniques in separate samples: normal controls and patients with severe lung interstitial pathologies. Perfusion studies using 99mTc-MAA have also been performed in all patients. The aerosols were produced using ultrasound and lowered surface tension solution of 99mTc-HMPAO and 99mTc-DTPA. The time-activity curves (TACs) for every pixel on the lung area were used to calculate the half-disappearance times (T1/2). Parametric images were then generated with those times. The comparison of the results obtained with 99mTc-HMPAO and 99mTc-DTPA aerosols suggests that the first ones are more specific for local alterations of the lung epithelial transport in the pathologies studied. This method distinguishes between permeability deficiency due to local perfusion decrease and ACB deterioration.

[Tomodensitometry and radioisotopic methods in the study of unilateral lung hyperlucencies of vascular origin]. / Tomodensitometria e métodos radioisotópicos no estudo das hipertransparências pulmonares unilaterais de causa vascular.

Among the causes of the radiological entity known as unilateral or total hyperlucent lung is the decreased blood flow in the lungs. Unilateral and total hyperlucent lung results, among other factors, from the decreased intrapulmonary blood flow. Classically, the diagnosis and haemodynamic evaluation of these situations were usually made through invasive methods: right heart catheterism to perform angiopneumography and pressure evaluations as well as oximetry at several levels of the vascular network, thoracic aortography eventually associated with selective arteriography to detect the abnormalities of the systemic thoracic circulation. In this context, the authors propose for the diagnosis and study of this pathology, a new non-invasive methodology. In order to achieve this propose, we studied 8 patients, all of them performed clinical and laboratory evaluations, chest chi-ray, electrocardiographic and functional respiratory exams, as well angiopneumography, thoracic aortography tomodensitometry including qualitative (to study the lung arterial vasculature) and quantitative (to evaluate CT density of each lung in Hounsefield unit and two radioisotopic tests, including a ventilation/perfusion study with 133 chi e and HAM-99mTc, through an original software--four parameter histograms allowing simultaneous information of ventilation and perfusion at the pixel level and estimation of the V/Q; the other is the pulmonary gating through which it is possible to identify and quantify the arterio-arterial shunts.(ABSTRACT TRUNCATED AT 250 WORDS)

Beyond the limits of oxygen: effects of hypoxia in a hormone-independent prostate cancer cell line.

Prostate cancer (PCa) has a high incidence worldwide. One of the major causes of PCa resistance is intratumoral hypoxia. In solid tumors, hypoxia is strongly associated with malignant progression and resistance to therapy, which is an indicator of poor prognosis. The antiproliferative effect and induced death caused by doxorubicin, epirubicin, cisplatin, and flutamide in a hormone-independent PCa cell line will be evaluated. The hypoxia effect on drug resistance to these drugs, as well as cell proliferation and migration, will be also analyzed. All drugs induced an antiproliferative effect and also cell death in the cell line under study. Hypoxia made the cells more resistant to all drugs. Moreover, our results reveal that long time cell exposure to hypoxia decreases cellular proliferation and migration. Hypoxia can influence cellular resistance, proliferation, and migration. This study shows that hypoxia may be a key factor in the regulation of PCa.