No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Inhibitory Effect of Globefish Homogenate on the Growth of Caco-2 Human Colorectal Cancer Cells
ResearchGate has not been able to resolve any citations for this publication.
Colorectal cancer (CRC) is the second most common cancer in women and the third most common in men globally. CRC arisesfrom one or a combination of chromosomal instability, CpG island methylator phenotype, and microsatellite instability. Geneticinstability is usually caused by aneuploidy and loss of heterozygosity. Mutations in the tumor suppressor or cell cycle genes mayalso lead to cellular transformation. Similarly, epigenetic and/or genetic alterations resulting in impaired cellular pathways, such asDNA repair mechanism, may lead to microsatellite instability and mutator phenotype. Non-coding RNAs, more importantlymicroRNAs and long non-coding RNAs have also been implicated at various CRC stages. Understanding the specific mechanismsof tumorigenesis and the underlying genetic and epigenetic traits is critical in comprehending the disease phenotype. This paperreviews these mechanisms along with the roles of various non-coding RNAs in CRCs.
Tetrodotoxin is a deadly neurotoxin which selectively inhibits Na(+) activation mechanism of nerve impulse, without affecting the permeability of K(+) ions. Because of this sodium channel blocking action, it is majorly being studied for biomedical applications. Tetrodotoxin is present in taxonomically diverse groups of animals inhabiting terrestrial, marine, fresh water and brackish water environments, still its origin remains unclear. The extensive study of the toxin has revealed a few possibilities of its origin. This review reports on the aspects of the origin of tetrodotoxin, where the primary focus is on its exogenous origin. The significance of bacterial, cellular and environmental factors in its biogenesis and accumulation is also discussed. The possible facets for engineering the bacterial genomics to modulate the gene expression for tetrodotoxin production is also outlined. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
Tetrodotoxin (TTX) is a naturally occurring toxin that has been responsible for human intoxications and fatalities. Its usual route of toxicity is via the ingestion of contaminated puffer fish which are a culinary delicacy, especially in Japan. TTX was believed to be confined to regions of South East Asia, but recent studies have demonstrated that the toxin has spread to regions in the Pacific and the Mediterranean. There is no known antidote to TTX which is a powerful sodium channel inhibitor. This review aims to collect pertinent information available to date on TTX and its analogues with a special emphasis on the structure, aetiology, distribution, effects and the analytical methods employed for its detection.
Colorectal cancer (CRC) is a leading cause of cancer deaths worldwide. It results from an accumulation of genetic and epigenetic changes in colon epithelial cells, which transforms them into adenocarcinomas. Over the past decade, major advances have been made in understanding cancer epigenetics, particularly regarding aberrant DNA methylation. Assessment of the colon cancer epigenome has revealed that virtually all CRCs have aberrantly methylated genes and that the average CRC methylome has hundreds to thousands of abnormally methylated genes. As with gene mutations in the cancer genome, a subset of these methylated genes, called driver genes, is presumed to have a functional role in CRC. The assessment of methylated genes in CRCs has also revealed a unique molecular subgroup of CRCs called CpG island methylator phenotype (CIMP) cancers; these tumors have a particularly high frequency of methylated genes. These advances in our understanding of aberrant methylation in CRC have led to epigenetic alterations being developed as clinical biomarkers for diagnostic, prognostic and therapeutic applications. Progress in this field suggests that these epigenetic alterations will be commonly used in the near future to direct the prevention and treatment of CRC.
HIV infections are mainly acquired by mucosal transmission, through oral, rectal, or genital mucosa. Epithelial cells (EC) are the first cells encountered by HIV during infection through sexual transmission and breastfeeding. EC express several receptors critical for both primary HIV infection and secondary transmission. The regulation of co-receptor expression correlates with changes in susceptibility to infection by HIV-1 strains with different tropism. Moreover, inflammatory responses at mucosal surfaces after HIV-1 transmission may influence disease outcome. In the present study, we analyzed the effect of the accessory HIV-1 Nef protein on mucosal EC, using unstimulated or IFN-γ-stimulated HEp-2, T24, and Caco2 cell lines as models for homeostatic or inflamed mucosal tracts. We found that Nef significantly upregulated the expression of CXCR4 on the Caco-2 cell surface and the expression of galactosylceramide on the T24 cell surface. In addition, Nef significantly upregulated IL-6 production by T24 and Caco-2 cells, and TNF-α release by all three cell lines analyzed. Notably, Nef abrogated the IFN-γ-induced modulation of co-receptor expression and cytokine secretion. Our findings suggest that Nef differently regulates co-receptor expression and cytokine secretion at the epithelial level, depending on the anatomical derivation of the cells and the inflammatory status.
The proteins encoded by ras and src protooncogenes are frequently activated in a constitutive state in human colorectal cancers. To investigate the mechanism(s) whereby oncogenic p21ras and pp60c-src contribute to malignant transformation of intestine, human colonic Caco-2 cells transfected with an activated (Val 12) human Ha-ras gene (Caco-2-T cells) or Py-MT oncogene, a constitutive activator of pp60c-src tyrosine kinase activity (Caco-2-MT cells), were analyzed for tumorigenicity, protein kinase C (PKC) isoform expression, and PKC activity. As compared with control vector Caco-2-H cells, Caco-2-T and Caco-2-MT cells displayed: (a) an enhanced tumorigenicity in nude mice; (b) a 4-fold increase in the level of PKC-alpha mRNA which was not due to enhanced mRNA stability and was mediated through a PKC-independent pathway since it persisted after PKC depletion; (c) increased PKC-alpha immunoreactive protein content (3-fold), total PKC catalytic activity (3.5-fold), and total cell number of [3H]phorbol-12,13-dibutyrate binding sites (4-fold); and (d) a 1.7-fold higher membrane-bound/total PKC activity ratio together with 1.8- and 1.5-fold increases in [3H]arachidonate- and [3H]myristate-labeled diacylglycerol levels. In conclusion, the tumorigenic progression induced by oncogenic p21ras or the Py-MT/pp60c-src complex in Caco-2 cells is associated with increased PKC-alpha gene transcription and PKC-alpha expression as well as with constitutive PKC activation. These results provide the first evidence that the PKC-alpha gene is a target for the signaling pathways of oncogenically activated p21ras and pp60c-src in human colonic cells. They raise the possibility that PKC-alpha is an effector of these oncoproteins for activation of Caco-2 cell tumorigenic potential.
Three species of pufferfishes (family Tetraodontidae) were examined to determine their morphological characteristics based on meristics, morphometrics, olfactory organs, and lateral line systems of specimens collected from the Chennai Fish Market in Tamil Nadu, India, in December 2016. The three species, which are all previously unreported in Korea, are Chelonodon patoca (Hamilton, 1822), Lagocephalus spadiceus (Richardson, 1845), and Arothron immaculatus (Bloch and Schneider, 1801). For nostril shape, fishes of the genus Lagocephalus have two nostrils, while Arothron and Chelonodon have none. Fishes of the genera Lagocephalus and Arothron have a single well-developed lateral line on the body, while Chelonodon fishes have two lateral lines that merge on the caudal peduncle.
Colorectal cancer (CRC) is one of the most common malignancies in the United States. Every 3 years, the American Cancer Society provides an update of CRC incidence, survival, and mortality rates and trends. Incidence data through 2013 were provided by the Surveillance, Epidemiology, and End Results program, the National Program of Cancer Registries, and the North American Association of Central Cancer Registries. Mortality data through 2014 were provided by the National Center for Health Statistics. CRC incidence rates are highest in Alaska Natives and blacks and lowest in Asian/Pacific Islanders, and they are 30% to 40% higher in men than in women. Recent temporal patterns are generally similar by race and sex, but differ by age. Between 2000 and 2013, incidence rates in adults aged ≥50 years declined by 32%, with the drop largest for distal tumors in people aged ≥65 years (incidence rate ratio [IRR], 0.50; 95% confidence interval [95% CI], 0.48-0.52) and smallest for rectal tumors in ages 50 to 64 years (male IRR, 0.91; 95% CI, 0.85-0.96; female IRR, 1.00; 95% CI, 0.93-1.08). Overall CRC incidence in individuals ages ≥50 years declined from 2009 to 2013 in every state except Arkansas, with the decrease exceeding 5% annually in 7 states; however, rectal tumor incidence in those ages 50 to 64 years was stable in most states. Among adults aged <50 years, CRC incidence rates increased by 22% from 2000 to 2013, driven solely by tumors in the distal colon (IRR, 1.24; 95% CI, 1.13-1.35) and rectum (IRR, 1.22; 95% CI, 1.13-1.31). Similar to incidence patterns, CRC death rates decreased by 34% in among individuals aged ≥50 years during 2000 through 2014, but increased by 13% in those aged <50 years. Progress against CRC can be accelerated by increasing initiation of screening at age 50 years (average risk) or earlier (eg, family history of CRC/advanced adenomas) and eliminating disparities in high-quality treatment. In addition, research is needed to elucidate causes for increasing CRC in young adults. CA Cancer J Clin 2017.
Each year, the American Cancer Society estimates the numbers of new cancer cases and deaths that will occur in the United States in the current year and compiles the most recent data on cancer incidence, mortality, and survival. Incidence data were collected by the Surveillance, Epidemiology, and End Results Program; the National Program of Cancer Registries; and the North American Association of Central Cancer Registries. Mortality data were collected by the National Center for Health Statistics. In 2017, 1,688,780 new cancer cases and 600,920 cancer deaths are projected to occur in the United States. For all sites combined, the cancer incidence rate is 20% higher in men than in women, while the cancer death rate is 40% higher. However, sex disparities vary by cancer type. For example, thyroid cancer incidence rates are 3-fold higher in women than in men (21 vs 7 per 100,000 population), despite equivalent death rates (0.5 per 100,000 population), largely reflecting sex differences in the "epidemic of diagnosis." Over the past decade of available data, the overall cancer incidence rate (2004-2013) was stable in women and declined by approximately 2% annually in men, while the cancer death rate (2005-2014) declined by about 1.5% annually in both men and women. From 1991 to 2014, the overall cancer death rate dropped 25%, translating to approximately 2,143,200 fewer cancer deaths than would have been expected if death rates had remained at their peak. Although the cancer death rate was 15% higher in blacks than in whites in 2014, increasing access to care as a result of the Patient Protection and Affordable Care Act may expedite the narrowing racial gap; from 2010 to 2015, the proportion of blacks who were uninsured halved, from 21% to 11%, as it did for Hispanics (31% to 16%). Gains in coverage for traditionally underserved Americans will facilitate the broader application of existing cancer control knowledge across every segment of the population. CA Cancer J Clin 2017. © 2017 American Cancer Society.
To identify the food component characteristics of seven edible pufferfishes (five wild pufferfishes including striped puffer Takifugu xanthopterus; eyespot puffer Takifugu chinensis; purple puffer Takifugu porphyreus; rough-backed puffer Lagocephalus wheeleri; and grass puffer Takifugu niphobles; and two cultured pufferfishes including yellow puffer Takifugu obscurus, and tiger puffer Takifugu rubripes) in Korea, the proximate, fatty/amino acid, chemical and taste compositions were investigated. The proximate compositions were not significantly different among the sampled pufferfishes, whereas grass puffer had lower moisture and crude lipid levels contents, and higher crude protein and ash contents than the other species. The total amino acid levels in wild and cultured pufferfishes were 14,941.6-16,427.9 mg/100 g, and the major amino acids were aspartic acid, glutamic acid, glycine, alanine, leucine, lysine and arginine. Regarding the fatty acid and mineral compositions, the major fatty acids included 22:6n-3, 16:0, 18:1n-9, 20:5n-3, 18:0, 20:4n-3, and 22:5n-3 in that order, and there was a little difference among the sampled pufferfishes. Grass puffer had a higher monoenes ratio, i.e., 16:1n-7 and 18:1n-9, and a lower polyenes ratio than the other pufferfishes. The main minerals detected K, P, Na, S and Ca. Regarding the taste-active compounds, the free amino acid contents of pufferfish extracts were 236.4-428.1 mg/100 g, consisting primarily of taurine, lysine, proline, glycine, alanine and arginine in that order. The amino nitrogen content of the pufferfishes was 84.5-156.4 mg/100 g, and there was a little difference among the species. As for taste intensity, the total taste value of the purple puffer was higher than that of the other pufferfishes.
Colorectal carcinomas (CRC) might be organized hierarchically and contain a subpopulation of tumorigenic, putative cancer stem cells that are CD133 positive. We studied the biological and genetic characteristics of such cells in CRC cell lines and primary tumors. Three CRC cell lines were sorted in CD133 positive and negative fractions. The respective genetic aberration profiles were studied using array comparative genomic hybridization (aCGH) and expression profiling. Tumorigenicity for each cellular population was tested by injection into nude mice. Additionally, we compared CD133+ and CD133- cells of 12 primary colorectal tumors using laser capture microdissection and aCGH. Three of five CRC cell lines displayed both CD133+ and CD133- cells, but tumorigenicity of these subfractions did not differ significantly and aCGH revealed essentially identical genomic imbalances. However, 96 genes were differentially expressed between the two populations. Array comparative genomic hybridization analysis after laser capture microdissection of CD133+ and CD133- areas in primary colorectal tumors revealed genetic differences in 7 of 12 cases. The use of cell lines for studying genomic alterations that define cancer stem cell characteristics, therefore, seems questionable. In contrast, CD133+ cells in primary cancer samples showed a unique genomic aberration profile. In conclusion, our data suggest that CD133 positivity defines a genetically distinct cellular compartment in primary CRC, which potentially includes tumor initiating cells.
Keywords: Tetrodotoxin; cultured puffer fish; organs; enzyme immunoassay
Caco-2 cells, which express spontaneous enterocytic differentiation at confluency, is one of the most relevant in vitro models for the study of differentiation and regulation of intestinal functions. However, these cells are normally cultured in the presence of 15-20% serum which renders extremely complex the identification of the factors involved in the regulation of both proliferation and differentiation. This study has been devoted to the establishment of chemically defined culture conditions which can sustain growth and differentiation of Caco-2 cells. The replacement of serum by ITS (insulin, transferrin, and selenium) allowed for normal structural and functional differentiation of cells as revealed by the establishment of cell polarity and the expression of brush-border membrane enzyme markers (sucrase, maltase, lactase, alkaline phosphatase, gamma-glutamyltransferase, aminopeptidase N, and dipeptidyl-dipeptidase IV), although the levels of sucrase activity were lower in ITS-supplemented medium. Coating petridishes with either type IV collagen or basement membrane proteins (Matrigel) did not improve the differentiation of cells, brush-border membrane enzyme activities being, in fact, lower when the cells were grown on these substrata. When triiodothyronine (T3, 5 x 10(-8) M) was added to the ITS-supplemented medium, disaccharidase and alkaline phosphatase activities were significantly increased while gamma-glutamyltransferase activity was diminished by T3 and stimulated by epidermal growth factor (1.6 x 10(-6) M). On the other hand, hydrocortisone (HC, 10(-6) M) did not modify disaccharidase and peptidase activities. These data clearly show that Caco-2 cells can be maintained in serum-free medium and that this system allows the study of the factors involved in the regulation of the differentiation of enterocyte in vitro.
The relationship known to exist in vitro between glycogen accumulation and the growth of malignant human intestine epithelial cells was investigated in vivo. The glycogen concentration of 7 human intestine carcinoma cell lines (Caco-2, HT-29, HRT-18, HCT-8R, CO-115, SW-480, and HuTu 80) was measured during cell growth for the in vitro series and during the course of tumor growth for the in vivo series. The glycogen stores were compared for these cells in vitro and after their injection in noninbred Swiss athymic nude mice. The tumors and cultured cells were ranked identically on the basis of glycogen level (Caco-2 > HRT-18 > HT-29 > HCT-8R > CO-115 > SW-480 > HuTu 80). Values for the tumors ranged from 128.8 +/- 10.8 micrograms glycogen/mg protein for Caco-2 tumors down to 2.9 +/- 0.9 micrograms for HuTu 80 tumors; similar values were found for the exponentially growing corresponding cultured cells. The tumor glycogen concentration was independent of the host's nutritional state: Glycogen concentration differed from one type of tumor to another despite its constant level in the liver; fasting did not cause tumor glycogenolysis. By the two experimental approaches, results varied during the growth phases: Stationary phase glycogen concentration increased threefold to fourfold for all cultured cell lines; tumor glycogen concentration, by contrast, was stable throughout the growth period. An inverse relationship was nonetheless found between the rate of tumor growth and tumor glycogen concentration; the highest glycogen content was associated with the slowest growing tumors, and conversely. Apparently, elevated glycogen concentration is regularly associated with decreased cell division rates in vitro and in vivo.
Activation of the p21ras and pp60c-src oncoproteins occurred at high incidence in the early stage of human colorectal carcinogenesis. Our study aimed to investigate the role of these signal-transduction pathways in the process of initiation and promotion of the malignant phenotype in intestinal cells.
The human Ha-ras and the polyoma middle T (Py-MT) viral oncogenes were transferred into large T oncogene of simian virus 40 immortalized rat intestinal epithelial SLC-44 cells and human colonic adenocarcinoma Caco-2 cells.
These transfers conferred the tumorigenic and invasive phenotypes on immortalized SLC-44 cells and potentiated the tumorigenicity of Caco-2 cells and markedly repressed the terminal differentiation of this cell line. In SLC-44T cells, induction of the invasive phenotype by the activated Ha-ras oncogene correlated with weak expression of E-cadherin and reduced accumulation of the transcripts encoding the basement membrane components alpha 1 (IV) collagen, nidogen, and BM40, which might result partly from the inactivation of the transforming growth factor beta signaling pathway. The down-regulation of the alpha 1 (IV) collagen messenger RNA in SLC-44T cells was not due to the protein kinase C-dependent pathways or the secretion of autocrine factor(s).
These results suggest that the activation of the p21ras and Py-MT/pp60c-src oncogenic pathways are critical effectors at different stages of colorectal carcinogenesis and in Caco-2 cells interferes with the program of enterocyte differentiation.
Cellular retinol binding protein II (CRBPII) is an abundant small intestinal protein that facilitates vitamin A trafficking and metabolism. The magnitude of retinol uptake and metabolism correlate to CRBPII levels in the human intestinal Caco-2 cell line. To investigate the importance of retinoic acid receptor response elements in the promoter of the CRBPII gene, retinoic acid regulation of CRBPII expression and vitamin A absorption was studied in differentiated Caco-2 cells. All-trans- or 9-cis-retinoic acid increased CRBPII mRNA levels two- to threefold. This was associated with a 50% increase in retinol absorption. Retinoic acid receptor beta and apolipoprotein A1 regulatory protein-1, two nuclear receptors that bind to the CRBPII promoter, were also induced, whereas other retinoid and orphan receptors were not. Thus, retinoic acid may regulate CRBPII expression directly or by selectively changing levels of nuclear receptors or other factors. These studies are the first to demonstrate that retinoic acid can modulate endogenous CRBPII mRNA levels and retinol absorption in Caco-2 cells and suggest that human intestinal vitamin A absorption may be regulated by retinoids.
Microsatellite instability (MSI) is characterized by the size variation of microsatellites in tumor DNA as compared to matching normal DNA due to defects in the mismatch repair system. To examine the chromosomal differences in microsatellite-stable (MSS) and -unstable (MSI) tumors in detail, we analyzed MSS (Caco-2, Colo-205, SW948) and MSI (HCT-15, HCT-116, LoVo) cell lines by spectral karyotyping (SKY).
SKY is a sensitive method to detect chromosome aberrations by visualizing each chromosome in a different color. Metaphases were hybridized with a SKY probe mixture. Images were visualized with the SpectraCube system and analyzed with the SKYview imaging software.
The average number of chromosomes was 49 in LoVo, 45 in HCT-116, 46 in HCT-15, 71 in Colo-205, 89 in Caco-2 and 66 in SW-948. Three aberrant chromosomes were detected in LoVo, three in HCT-116, two in HCT-15, seventeen in Colo-205, fourteen in Caco-2 and nine in SW948.
The karyotypes of MSS colon cancer cells displayed complex numerical and structural aberrations. In contrast the chromosomes of MSI colon cancer cells were mostly unaltered but displayed a few isolated numerical and structural aberrations. We speculate that these isolated aberrations may be specifically involved in the pathogenesis of MSI tumors.
A study on the generative reason of the toxicity for the pufferfish
- Jang