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Chemopreventive effects of orally administered Nigella sativa oil on the induction and development of 1,2-dimethylhydrazine-induced aberrant crypt foci (ACF), putative preneoplastic lesions for colon cancer, were investigated in Fischer 344 rats. Starting at 6 wk of age, 45 male rats (groups 1-3) were subcutaneously injected with DMH once a week for 3 wk. Group 1 (15 rats) served as a carcinogen control group without N. sativa administration. Group 2 or 3 (15 rats each) were given the oil in the postinitiation stage or in the initiation stage, respectively. Animals of group 4 (11 rats) were injected with 0.9% saline and received N. sativa oil from the beginning until the termination. At sacrifice, 14 wk after the start, the total numbers of ACF as well as those with at least four crypts were significantly reduced in group 2 (P < 0.01). However, treatment with N. sativa oil in the initiation stage (group 3) did not exhibit significant inhibitory effects except on foci with only one aberrant crypt. Immunohistochemical analysis of 5-bromo-2'-deoxyuridine labeling in colonic crypts revealed the N. sativa oil to have significant antiproliferative activity in both initiation and postinitiation stages and especially in the latter. Histological examination revealed no pathological changes in the liver, kidneys, spleen, or other organs of rats treated with N. sativa. In addition, biochemical parameters of blood and urine as well as body weight gain were not affected. These findings demonstrate that the volatile oil of N. sativa has the ability to inhibit colon carcinogenesis of rats in the postinitiation stage, with no evident adverse side effects, and that the inhibition may be associated, in part, with suppression of cell proliferation in the colonic mucosa. [ABSTRACT FROM AUTHOR]

Atorvastatin (ATOR) acts on certain antitumor pathways; the consequences of chemotherapies continue to be a major concern, notwithstanding the increased efficacy provided by contemporary therapies. This study investigated the synergistic effects and underlying mechanisms of different treatment protocols using ATOR on the THP-1 cell line and on lung cancer in mice. For the in vitro study, an MTT assay was performed, and then different combinations against the THP-1 cell line were used as follows: non-treated cells, THP-1/ATOR IC 50 , THP-1/cytarabine (CYT) IC 50 , THP-1/doxorubicin (DOX) IC 50 , THP-1/DOX/CYT, THP-1/ATOR/CYT, THP-1/ATOR/DOX, and THP-1/ATOR/CYT/DOX. For the in vivo study, CD-1 male mice were used; G1 was the normal control. Gs2-5 were administered with urethane (Ure) and butylated hydroxytoluene (BHT). G2 was the positive control. G3 was treated with ATOR (20 mg/kg). G4 was treated with Bevacizumab (Bev) (5 mg/kg). G5 was co-treated with ATOR/Bev. Histopathological and immunohistochemical investigations, flow cytometry and molecular analysis of PI3K, Akt, and mTOR genes were performed after different treatment protocols. The results showed that different combinatorial treatment settings of ATOR in vitro increase the apoptotic-inducing capacity and cell cycle arrest. Co-treatment with ATOR and Bev led to a significant decrease in S-phase and G2/M percentages. Furthermore, in vivo co-treatment with ATOR/Bev decreased tumor incidence and size with a significant reduction of the immunohistochemical PCNA (LI%) in lung parenchyma, targeting PI3K/Akt/mTOR, and VEGF-A signaling pathways. Co-treatment with ATOR and chemotherapies led to cell cycle arrest, modulation of the PI3K/Akt/mTOR, and VEGF-A signaling pathways in tumor cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Nowadays, the use of food additives, such as Sunset Yellow (SY), is growing, which attracted attention to the potential relationship between some diseases and food additives., Aim: The study aimed to investigate the role of Sunset Yellow during chemically-induced mammary gland carcinogenesis in Sprague-Dawley rats., Material and Methods: Three groups of female rats were intraperitoneally administered with N-methyl-N-nitrosourea (MNU). Group 1 was set on a basal diet. Group 2 was treated with 161.4 mg\kg\day Sunset Yellow (SY). Group 3 was given SY at 80.7 mg\kg\day. Groups 4-6 were not administered MNU; Group 4 received vehicles only. Groups 5 and 6 were administered SY similarly to groups 2 and 3 respectively., Results: Sunset Yellow at both doses exerted a significant dose-dependent increase in tumor incidences, multiplicities, volumes, and decreased tumor latency as compared with control. Immunolabeling indexes of the proliferating cell nuclear antigen, estrogen receptor alpha, and progesterone receptor were significantly increased after SY treatment. Oxidative stress markers, serum estrogen, progesterone, and prolactin levels were significantly modified by SY treatment. The mRNA expression of estrogen receptor alpha and epidermal growth factor was up-regulated in SY groups versus control., Conclusion: Collectively, SY has significantly promoted MNU-induced mammary tumors in rats with underlying mechanisms correlating SY consumption with estrogen disruption and subsequent antioxidative stress discrepancy., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Background: Due to the limited success in the treatment of lung adenocarcinomas, new treatment protocols are urgently needed to increase the curability rate and the survival of lung cancer patients., Objectives: Although statins, like atorvastatin (Ator), and metformin (Met) are widely accepted as hypolipidemic and hypoglycemic drugs, respectively, there are many predictions about their enhancing antitumor effect when they are combined with traditional chemotherapeutics., Methods: The individual and combined antiproliferative potential of Ator and Met was tested by MTT-assay in non-small cell lung cancer (NSCLC) A549 cell line, compared to the corresponding effect of Gemcitabine (Gem) with implication on the mechanisms of action., Results: Initially, both drugs demonstrated concentration-dependent cytotoxicity in A549 cells. Also, their combination index (CI) indicated their synergistic effect at equi-IC50 concentration (CI = 0.00984). Moreover, Ator and/or Met-treated cells revealed disrupted patterns of SOD, CAT, GSH, MDA, and TAC, developed apoptosis, and larger fractions of the cell population were arrested in G0/G1 phase, particularly in cells dually-treated both Ator and Met. These observations were accompanied by downregulation in the expression of iNOS, HO-1, and the angiogenic marker VEGF, meanwhile, an altered expression of MAPK and AMPK was observed., Conclusion: Conclusively, these data suggest that repurposing of Ator and Met demonstrates their individual and combined antiproliferative effect in non-small cell lung cancer and they may adopt a similar mechanism of action., (© 2024 Société Française de Pharmacologie et de Thérapeutique. Published by John Wiley & Sons Ltd.)

Background: Cancer is a fatal disease that severely affects humans. Designing new anticancer strategies and understanding the mechanism of action of anticancer agents is imperative., Hypothesis/purpose: In this study, we evaluated the utility of metformin and D-limonene, alone or in combination, as potential anticancer therapeutics using the human liver and breast cancer cell lines HepG2 and MCF-7., Study Design: An integrated systems pharmacology approach is presented for illustrating the molecular interactions between metformin and D-limonene., Methods: We applied a systems-based analysis to introduce a drug-target-pathway network that clarifies different mechanisms of treatment. The combination treatment of metformin and D-limonene induced apoptosis in both cell lines compared with single drug treatments, as indicated by flow cytometric and gene expression analysis., Results: The mRNA expression of Bax and P53 genes were significantly upregulated while Bcl-2, iNOS, and Cox-2 were significantly downregulated in all treatment groups compared with normal cells. The percentages of late apoptotic HepG2 and MCF-7 cells were higher in all treatment groups, particularly in the combination treatment group. Calculations for the combination index (CI) revealed a synergistic effect between both drugs for HepG2 cells (CI = 0.14) and MCF-7 cells (CI = 0.22)., Conclusion: Our data show that metformin, D-limonene, and their combinations exerted significant antitumor effects on the cancer cell lines by inducing apoptosis and modulating the expression of apoptotic genes., (© 2024. The Author(s).)

Breast cancer ranks as the second leading most significant of mortality for women. Studies have demonstrated the potential benefits of natural compounds in cancer treatment and prevention, either in isolation or in conjunction with chemotherapy. In order to improve Tamoxifen's therapeutic efficacy in in-vivo studies, our research sought to determine the effects of hesperidin, piperine, and bee venom as natural compounds, as well as their combination effect with or without Tamoxifen. First, 132 female albino rats were equally divided into six groups and five subgroups, and breast cancer was induced in the selected groups by xenografting of MCF7 cells. Second, the effect of single and best ratio combinations treatment from previous in vitro studies were selected. Next, tumorous mammary glands were collected for apoptotic and antiapoptotic biomarkers and cell cycle analysis. Single or combined natural products with or without Tamoxifen revealed a significant up-regulation in apoptotic genes Bax and Casp3 and a downregulation of antiapoptotic and angiogenesis genes Bcl-2 and VEGF genes. We found that cell cycle arrest in the G0/G1 phase was exclusively caused by Tamoxifen and/ or hesperidin. However, the cell cycle arrest in the G2/M phase is a result of the combination of piperine and bee venom, with or without Tamoxifen by using the flow cytometric technique. Our research concludes that bee venom, hesperidin, and piperine can synergistically enhance to increase Tamoxifen's efficiency in the management of breast cancer., (© 2024. The Author(s).)

The widespread biomedical and commercial applications of silver nanoparticles (AgNPs) have increased their potential for human and environmental exposure and toxicity to human health. The bio-distribution and toxicity of AgNPs in rodents following inhalation, intratracheal instillation, and oral ingestion are well documented; however, little is known about the bio-distribution of intravenously (IV)-administered AgNPs and their organ-specific pathophysiological effects. Here, we investigate the pharmacokinetic pattern and tissue distribution of AgNPs in male rats following IV administration. The animals were humanely sacrificed after 10 min, 1 h, 6 h, 12 h, 24 h, and 168 h of AgNP administration, and the silver (Ag) content was measured from blood samples and various tissues following acid digestion. The AgNPs were readily absorbed and subsequently distributed into most organs predominantly in the colon, small intestine, kidney, and heart after 6 h; however, they were the highest in the spinal cord after 168 h. White blood cells (WBCs) were significantly increased (42-60%) in AgNP-administered animals at all time points except 10 min. Regarding platelets, all AgNP-administered animals showed counts 7.8-39.2% lower, with the lowest count at 168 h post-administration. In the case of lymphocytes (LYMs), the AgNP-treated animals exhibited a count 19.5-41% lower at 10 min and 1 h post-administration; however, the animals at 168 h post-administration showed a count 30.5% more. The mean corpuscular hemoglobin (MCH) counts from the AgNP-treated animals were decreased by 50-62%. The concentrations of aspartate transaminase (AST), urea, and creatinine were increased in the AgNP-treated animals. Taken together, the results suggest that the acute IV administration of AgNPs alters metabolic and hematological parameters in animals and may pose a health risk to humans.

A quantitative assessment of silver nanoparticles (AgNPs) in fluids and some organs of pregnant rats as well as their fetal blood were carried out in this study. A single oral dose (1mg/kg) of AgNPs with a size range of 4-20 nm was administered to pregnant rats on the 19th of gestation. Five groups were euthanized after 10 min, 1, 6, 12, and 24 hr as well as the control group. Total Silver (Ag) contents were measured in bloods (maternal and fetal) and several organs using Inductive Coupled Plasma Optical Emission Spectroscopy (ICP-OES) followed by acid digestion. In maternal blood, AgNPs were found to increase time-dependently after 12 and 24 hr into 0.135 and 0.224 μg/ml, but it was slightly higher in fetal blood (0.32 and 0.31 μg/ml) after 10 min and 1 hr. In other samples: kidneys, liver, spleen, placenta, and uterus the data indicated that NPs were rapidly absorbed from the dosing site (gastrointestinal tract) as evidenced by the detection of Ag in the analyzed samples (fluids and tissues). On the other hand, the cumulative percentages of excretion level in urine was 8.25% which was higher than in feces (4.77%) after 24 hr. These findings indicate the ability of AgNPs to accumulate in pregnant rats and transfer to their fetus imposing adverse outcomes and male formation. Thus, further investigations must be followed for direct and/or indirect exposure to such NPs before decision for their practices.

Bevacizumab (Bev) a humanized monoclonal antibody that fights vascular endothelial growth factor A (VEGF-A). It was the first specifically considered angiogenesis inhibitor and it has now become the normative first-line therapy for advanced non-small-cell lung cancer (NSCLC). In the current study, polyphenolic compounds were isolated from bee pollen (PCIBP) and encapsulated (EPCIBP) inside moieties of hybrid peptide-protein hydrogel nanoparticles in which bovine serum albumin (BSA) was combined with protamine-free sulfate and targeted with folic acid (FA). The apoptotic effects of PCIBP and its encapsulation (EPCIBP) were further investigated using A549 and MCF-7 cell lines, providing significant upregulation of Bax and caspase 3 genes and downregulation of Bcl2, HRAS, and MAPK as well. This effect was synergistically improved in combination with Bev. Our findings may contribute to the use of EPCIBP simultaneously with chemotherapy to strengthen the effectiveness and minimize the required dose.

Gemcitabine was loaded in albumin nanoparticles then coated with chitosan. The diameter of GEM-ANPs/CS was 200 ± 4 nm. Gemcitabine was loaded in GEM-ANPs/CS with an efficacy of 75%. The IC 50 of GEM-ANPs/CS was found to be 12.98 and 6.08 μg/ml after incubation for 48 and 72 h with MCF-7 cells, respectively. Treatment of MCF-7 cells with IC 50 of GEM-ANPS, and GEM-ANP S /CS resulted in membrane damage which led to elevated LDH activity of 4 and 3.4, and increasing GSH level of 4.6 and 9.3, respectively, when compared with untreated cells. DNA fragmentation and up-regulated of caspase-3 and p53 had illustrated the apoptotic effect of MCF-7 treated with GEM-ANP S /CS. The tumour suppressor RRM1 gene expression was down-regulated in MCF-7 cells treated with GEM-ANP S /CS. The modified ANPs coated with chitosan may be used as a promising nanomatrix for gemcitabine delivery and targeting to improve its therapeutic index against MCF-7 cells.

Objective: Uterine or endometrial cancer affects many women postmenopausal and may reach an advanced stage before signs and symptoms can be noticed. Micro RNAs (miRNAs), non-coding RNAs, play key roles in gene expression regulation and are linked to cancer. This study aimed to elucidate whether some specific types of miRNAs (miRNA133-a, miRNA-21, miRNA-205) can act as prognostic or diagnostic biomarkers for endometrial carcinoma (ER) in Egyptian patients., Methods: Blood samples from 36 patients suffering from endometrial carcinoma and 15 healthy volunteers were tested for expression levels of miRNA 133a-2, 21 and 205., Results: The expression levels of miRNA133a-2, miRNA-21, and miRNA-205 were significantly elevated in ER patients when compared with the control group, the highest levels were noticed in miRNA133a-2. The CA125 levels were significantly higher in all patients as compared with healthy subjects., Conclusion: The findings could support the use of circulating miR133a-2, miR-21 and miR-205 as virtuous prognostic biomarkers for EC in Egyptian patients. The studied miRNA species warrant validation for prospective targeting inhibitory protocols in EC.

The journal of APJCP (Asian Pacific Journal of Cancer Prevention) focuses to gather relevant and up-to-date novel information's related to cancer sciences. The research methodologies and approaches adopted by the researcher are prone to variation which may be desirable in the context of novel scientific findings however, the reproducibility for these studies needs to be unified and assured. The reproducibility issues are highly concerned when preclinical studies are reported in cancer, for natural products in particular. The natural products and medicinal plants are prone to a wide variation in terms of phytochemistry and phyto-pharmacology, ultimately affecting the end results for cancer studies. Hence the need for specific guidelines to adopt a best-practice in cancer research are utmost essential. The current AIMRDA guidelines aims to develop a consensus-based tool in order to enhance the quality and assure the reproducibility of studies reporting natural products in cancer prevention. A core working committee of the experts developed an initial draft for the guidelines where more focus was kept for the inclusion of specific items not covered in previous published tools. The initial draft was peer-reviewed, experts-views provided, and improved by a scientific committee comprising of field research experts, editorial experts of different journals, and academics working in different organization worldwide. The feedback from continuous online meetings, mail communications, and webinars resulted a final draft in the shape of a checklist tool, covering the best practices related to the field of natural products research in cancer prevention and treatment. It is mandatory for the authors to read and follow the AIMRDA tool, and be aware of the good-practices to be followed in cancer research prior to any submission to APJCP. Though the tool is developed based on experts in the field, it needs to be further updated and validated in practice via implementation in the field.

Gemcitabine is a chemotherapeutic drug used to treat cancer; however, it has severe side effects. Therefore, we evaluated the anticancer potency of balanitoside, a folk medicine isolated from the edible fruits of Balanites aegyptiaca , using a mouse model of lung cancer induced by Urethane/butylated hydroxytoluene, either alone or in combination with gemcitabine. The results indicated that balanitoside, when administered alone or in combination with gemcitabine, exhibited antitumor activity against lung cancer by reducing tumor incidence, multiplicity, and average tumor size. It also decreased the proliferation of tumor cells, induced apoptosis, triggered cell cycle arrest at the G0/G1 phase, and caused a marked reduction in cancer stem cell markers, aldehyde dehydrogenase (ALDH-1) levels, and the CD133 (+ve) cell population. Balanitoside also modulated the levels of oxidative stress markers in lung tissues. The results indicate that balanitoside enhances the antitumor activity of gemcitabine and may represent a natural adjuvant medication for lung cancer.

Objectives: This work was designed to compare the sensitizing effects of epigenetic modifiers on cancer cells vs. that of glucocorticoids. Also, to evaluate their effects on genes involved in epigenetic changes and drug metabolism., Methods: Hepatoma cells (HepG2) were treated with the anticancer drug (Taxol), with a histone deacetylase inhibitor (Trichostatin A [TSA]), DNA methyltransferase inhibitor (5-Aza-dC) or dexamethasone (DEX). Cytotoxicity was assessed by MTT assay and the apoptosis was determined by Annexin V-FITC. The expression levels of HDAC1 , HDAC3 , Dnmt1 , Dnmt3α, CYP1A2, CYP3A4, CYP2B6, CYP2C19 and CYP2D6 were monitored by qRT-PCR., Results: TSA, synergistically enhanced cells sensitivity with the anticancer effect of Taxol more than 5-Aza-dC and DEX. This was evidenced by the relative decrease in IC 50 in cells cotreated with Taxol + TSA, Taxol + 5-Aza-dC or Taxol + DEX. Apoptosis was induced in 51.2, 16.9 and 41.3% of cells, respectively. In presence of Taxol, TSA induced four-fold increase in the expression of HDAC1 and downregulated Dnmt1&3α genes . CYP2D6 demonstrated progressive expression (up to 28-fold) with the increasing number of drugs. Moreover, the isoform overexpressed in cells treated with TSA + Taxol > DEX + Taxol > 5-Aza-dC + Taxol (6.4, 4.6 and 2.99, respectively). The investigated genes were clustered in two distinct subsets, where no coregulation was observed between HDAC1 and HDAC3. However, tight pairwise correlation-based cluster was seen between ( CYP3A4/Dnmt3α and CYP2D6/CYP2C19)., Conclusions: The data reflects the sensitizing effect of acetylation modification by TSA on the responsiveness of hepatoma cells to anticancer therapy. The effect of histone deacetylase inhibition was more than hypomethylation and glucocorticoid effects. TSA exerts its role through its modulatory role on epigenetics and drugs metabolizing genes. Other modifiers (5-Aza-dC and DEX), however may adopt different mechanisms., (© 2021 Walter de Gruyter GmbH, Berlin/Boston.)

Objective: In search for a unique natural combination of highly active biological components for treatment against colon cancer, we used aqueous extract of Ascidia, Styela plicata (ASCex), a marine invertebrate depending on its richness of high levels of biologically active components as indicated in our previous studies, against rat colon cancer, exploring its underlying mechanisms., Methods: Rats chemically initiated for colon cancer were either non-treated or post-treated with highly saturated ASCex for 32 weeks after initiation, other groups of rats were administered ASCex without cancer initiation or served as normal controls., Results: Rats treated with ASCex alone did not show any signs of non-favored health conditions. Treatment with ASCex after cancer initiation has significantly reduced the average incidences, multiplicities and volumes of colon tumors (adenomas and adenocarcinomas) as compared with the non-treated cancer group. ASCex has also significantly reduced the total numbers of aberrant crypt foci (ACF), surrogate biomarkers for colon cancer as compared with the non-treated cancer group. Moreover, anti-proliferative celluar nucular antigen (PCNA) immunohistochemical staining revealed that ASCex exerted significant antiproliferative characteristics in the carcinogen-treated colonic mucosa as compared with its corresponding control. Also, treatment with ASCex has markedly down-regulated the mRNA expression levels of Nuclear Factor-kappa B (NF-κB), a nuclear transcriptional activator as well as the mRNA expression of the cytoplasmic SOD1 gene which encodes Cu/Zn SOD, the first line defense against superoxide radicals., Conclusion: Collectively, ASCex could act as a potent chemotherapeutic drug against colon cancer, likely through the influence of its rich active metabolites which interfere with various biological pathways including inhibition of protein synthesis during cellular growth and marked induction of antioxidative capacity in the colonic mucosa. This role has been extensively discussed herein.

This study was designated to explore the role of cancer stem cells (CSCs) during chemically induced mouse colon carcinogenesis (by 1,2- dimethylhydrazine dihydrochloride, DMH) with/or without the treatment with a targeted (anti-COX-2) therapeutic drug, celecoxib. Two experiments were conducted. The first, a short-term, 16-week mouse colon carcinogenesis bioassay, demonstrates the early stages of colon carcinogenesis. The other is a medium-term, 32-week mouse colon cancer experiment that mimics an end point of colon malignancy. Colon tumors were detected in animals after 32 weeks; histopathologically, they varied from benign hyperplastic polyps and adenomas to dysplastic polyps, adenocarcinomas, and invasive carcinomas. The overall colon tumor incidences, multiplicities, and volumes were obviously reduced when treated with celecoxib after DMH initiation. The immunohistochemical (IHC) labeling indexes (L1%) of the proliferating cell nuclear antigen (PCNA) were lower in the colonic epithelium in both experiments after treatment with celecoxib. Also, the IHC expression patterns of CD133 and CD44, known to associate CSCs, showed differential changes depending on the end-point stage of carcinogenesis and celecoxib treatment. Moreover, the biochemical aldehyde dehydrogenase-1 (ALDH-1) activity levels, a known CSC marker in colonic epithelia, were downregulated after 16 weeks but were upregulated after 32 weeks. Flow cytometric analysis showed that numbers of CD133 cells increased in the colonic epithelia of mice after 16 weeks, while the numbers of CD44 but not CD133 cells increased after 32 weeks. Treatment with celecoxib after DMH induced significant increase in apoptotic cell numbers by 47% after 16 weeks, but these numbers had not changed after 32 weeks compared with the corresponding group treated DMH only. Thus, the specific markers and CSC populations targeted by this drug may vary depending on the genetic and phenotypic stages of carcinogenesis. This drug could be useful during targeted therapy for colon cancer patients.

Methotrexate (MTX) is effective therapeutic agent treated many tumors and autoimmune diseases. The aim of our study was to design an effective delivery nanocarrier for methotrexate to improve stability and biodistribution, reduce adverse effects and maximize clinical efficacy. Magnetite nanoparticles (Fe 3 O 4 -NPs) were synthesized using Pterocladiella. The size of Fe 3 O 4 -NPs, CS-Fe 3 O 4 -NPs and MTX/CS-Fe 3 O 4 -NPs were 37.6, 61.4 and 150 nm respectively. Methotrexate loading efficiency was 74.15% of total amount of MTX loaded on CS-Fe 3 O 4 -NPs and 39.8% of the loaded drug was initially released and the remaining amount was released through 120 h. The IC 50 of MTX and MTX/CS-Fe 3 O 4 -NPs was 51.4 and 9.7 μg/ml respectively after 72 h. MTX/CS-Fe 3 O 4 -NPs caused remarkable damage to the membrane of MCF-7 cells led to increasing the LDH activity 5 fold in MCF-7 cells as compared with MTX treated once. DNA fragmentation and caspase-3 activity were higher in MCF-7 cells treated with MTX/CS-Fe 3 O 4 -NPs than that of MTX. Up-regulation of caspase3 and DHFR genes expression was observed in the treatment with MTX/CS-Fe 3 O 4 -NPs. The loading of MTX on chitosan coated Fe 3 O 4 -NPs improves the release and anticancer efficacy of MTX for effective cancer treatment., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Despite advances in cancer treatment, breast cancer remains one of the main life threatening diseases in women. Most anti-breast cancer drugs cause severe health complications and multidrug resistance. Although, some natural products, such as hesperidin (Hes), piperine (Pip) and bee venom (BV), showed anti-breast cancer effect when used separately, their combined effect together or with the anti-cancer drug tamoxifen (Tam) has not yet been studied. Herein, we hypothesized that these three natural products could potentiate the therapeutic effect of Tam when used together. First, we studied the cytotoxic effect of Hes, Pip, and BV on MCF7 and T47D cells using MTT assay and found reasonable IC 50 comparable to that of Tam. Second, we checked the effect of all combinations (n = 67 for each cell line, prepared as non-constant ratio from fractions of IC 50 of the four compounds) and found enhanced anti-proliferative effects on MCF7 and T47D and synergistic effect, revealed by combination index (CI) values below one. Next, the best 5 combinations with lowest Tam doses and CI but with highest cell death were selected for further molecular analysis in comparison to single-drug treatment. All single- and combined-treated groups showed a significant increase in apoptosis (indicated by upregulated mRNA level of the pro-apoptotic marker Bax and downregulated mRNA level of the anti-apoptotic marker Bcl2) and a significant decrease in mRNA level of the two breast cancer related receptors EGFR and ERα, with the best effect in combined groups especially that contained the 4 compounds, as compared to vehicle-treated group. Moreover, Pip, BV and all combinations, except Tam + Hes group, arrested MCF7 and T47D in G2/M phase of cell cycle, while Tam and/or Hes caused G0/G1 phase arrest. These results indicate that Hes, Pip and BV synergistically enhance the anti-cancer effect of Tam and could be used as safe adjuvant/vehicle to Tam in treatment of breast cancer after further confirmatory in vivo investigations., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Accumulating evidence suggest that some infectious agents may interfere in the natural progression of neoplasia. This study examined the association between chronic infection with adult Syphacia muris parasites and 1,2-dimethylhydrazine (DMH)-induced colorectal carcinogenesis in rats. In addition, the conceivable therapeutic effect of Bryostatin-1, a potent extract of the marine Bryozoan, Bugulane ritina, was investigated against this combined effect.DMH administration has induced aberrant crypt foci (ACF), surrogate biomarkers for colorectal carcinogenesis, while the S. muris infection combined with DMH has significantly increased the total numbers of ACF. Nonetheless, treatment with Bryostatin-1 after infection has significantly reduced the ACF numbers particularly larger ones. This inhibition was concomitant with significant inhibition in the immunohistochemical levels of the ki67, Caspase-3 and IgM levels in colorectal epithelium, as well as serum levels of IgM and IgG. Additionally, treatment with Bryostatin-1 after S. muris + DMH has modulated enzymatic antioxidative markers levels of superoxide dismutase and catalase as well as the non-enzymatic antioxidant markers levels of reduced glutathione, lipid peroxidation, nitric oxide and total antioxidant capacity. Further, treatment with Bryostatin-1 has down-regulated the mRNA expression levels of COX-2 and APC genes in colorectal mucosa. In conclusion, infection with S. muris during colorectal carcinogenesis has significantly modulated the oxidative stress markers in the colorectum, while treatment with Bryostatin-1 has exerted significant curative potential. A mechanism could be explained that Bryostatin-1 treatment has reduced oxidative stress markers activities along with affecting host to parasite immunity possibly leading to changes in the COX-2 and APC expression, retarding cellular proliferation and subsequently reducing the colorectal carcinogenesis events.

Grape seed proanthocyanidin extract (GSPE) is known to be effective on broad spectrum of biological pathways in living organisms including oxidative stress. The present study aimed to investigate the effects of proanthocyanidin on preneoplastic lesions and liver cancer induced in rats by Diethylnitrosamine (DEN). 7-8 Week old male Sprague Dawley (S.D.) rats were divided into six groups: The 1st group received no treatment and were -ve controls, the 2nd were treated with a single dose of DEN 200mg/kg intraperitoneally (i.p.) and served as +ve control group. The 3rd and 4th groups were injected with the same dose of DEN as in group 2 and then post treated with 300 or 150mg/kg/b.wt./day GSPE by intrgastroluminal gavage (i.g.) respectively until the end after the 22 weeks. Groups 5 and 6 were treated with the same doses of GSPE as in groups 3 and 4 respectively without DEN administration. The results showed that the immunohistochemical Proliferating Cell Nuclear Antigen (PCNA) labeling indexes (PCNA LI%) were significantly inhibited in liver tissues and tumors by both treatments of GSPE. Furthermore, treatment with GSPE has modified the liver tissue oxidative stress markers levels of SOD, CAT, GSH, GST, GPx, GR and MDA changed by DEN. In conclusion, GSPE has a sufficient therapeutic effect against liver carcinogenesis through their free radical scavenging, inhibition of cellular proliferation., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

The purpose of this study was to investigate the role of colon cancer stem cells (CSCs) during chemicallyinduced rat multi-step colon carcinogenesis with or without the treatment with a specific cyclooxygenase-2 inhibitor drug (celecoxib). Two experiments were performed, the first, a short term 12 week colon carcinogenesis bioassay in which only surrogate markers for colon cancer, aberrant crypt foci (ACF) lesions, were formed. The other experiment was a medium term colon cancer rat assay in which tumors had developed after 32 weeks. Treatment with celecoxib lowered the numbers of ACF, as well as the tumor volumes and multiplicities after 32 weeks. Immunohistochemical proliferating cell nuclear antigen (PCNA) labeling indexes LI (%) were downregulated after treatment by celecoxib. Also different cell surface antigens known to associate with CSCs such as the epithelial cell adhesion molecule (EpCAM), CD44 and CD133 were compared between the two experiments and showed differential expression patterns depending on the stage of carcinogenesis and treatment with celecoxib. Flow cytometric analysis demonstrated that the numbers of CD133 cells were increased in the colonic epithelium after 12 weeks while those of CD44 but not CD133 cells were increased after 32 weeks. Moreover, aldehyde dehydrogenase-1 activity levels in the colonic epithelium (a known CSC marker) detected by ELISA assay were found down-regulated after 12 weeks, but were up-regulated after 32 weeks. The data have also shown that the protective effect of celecoxib on these specific markers and populations of CSCs and on other molecular processes such as apoptosis targeted by this drug may vary depending on the genetic and phenotypic stages of carcinogenesis. Therefore, uncovering these distinction roles of CSCs during different phases of carcinogenesis and during specific treatment could be useful for targeted therapy.

It has been shown previously that nutritional supplements rich in polyphenolic compounds play a significant role in prostate cancer chemoprevention. Propolis is a natural, resinous hive product that has several pharmacological activities including antimicrobial, antioxidant, anti-inflammatory, and antitumoral activities. The aim of this study was to compare the cytotoxic, antioxidant and antitumoral activities of an ethanolic extract of Egyptian propolis (EEP) in vitro with an established chemotherapeutic drug such as doxorubicin (DOX), and the effects of their combination against the PC3 human prostate cancer cell line. Cellular viability and IC50 levels with EEP, DOX and their (v/v) combination were detected by sulphorhodamine-B (SRB) assay after incubation of PC3 cells for 72 h with different doses (0, 0.01, 0.1, 1, 10 and 100 μg/ml). Two selected doses of IC50 and IC25 were applied to cells for 24h for antitumor evaluation assay of treatment compounds. EEP and its (v/v) combination with DOX showed significant antitumor potential besides high antioxidant properties of superoxide dismutase (SOD), total antioxidant capacity (TAC), catalase (CAT), nitric oxide (NO) and reduced glutathione (GSH) levels when compared with the control untreated cells. DNA fragmentation assay and semi quantitative RT-PCR analyses for p53 and Bax genes showed that EEP activated cellular apoptosis and increased the mRNA expression levels more than other treatment. In conclusion, EEP alone or in combination with DOX at both doses used here showed greater antioxidant, antiproliferative and apoptotic effects against the PC3 cell lines as compared to treatment with DOX alone. Therefore, EEP could be considered as a promising candidate for prostate cancer chemotherapy.

Urinary bladder squamous cell carcinoma (SCC), one of the most common neoplasms in Egypt, is attributed to chronic urinary infection with Schistosoma haematobium (Schistosomiasis). The proto-oncogene c-KIT, encoding a tyrosine kinase receptor and implicated in the development of a number of human malignancies, has not been studied so far in schistosomal urinary bladder SCCs. We therefore determined immunohistochemical (IHC) expression of c-KIT in paraffin sections from 120 radical cystectomies of SCCs originally obtained from the Pathology Department of Suez Canal University (Ismailia, Egypt). Each slide was evaluated for staining intensity where the staining extent of >10% of cells was considered positive. c-KIT overexpression was detected in 78.3% (94/120) of the patients, the staining extents in the tumor cells were 11-50% and >50% in 40 (42.6%) and 54 (57.4%) respectively. The positive cases had 14.9%, 63.8%, 21.3% as weak, moderate and strong intensity respectively. Patients with positive bilharzial ova had significantly higher c-KIT expression than patients without (95.2% vs. 38.9%, P=0.000). Mutation analysis of exons 9-13 was negative in thirty KIT positive cases. The high rate of positivity in SBSCC was one of the striking findings; However, CD117 may be a potential target for site specific immunotherapy to improve the outcome of this tumor.

Diallyl sulfide (DAS), a flavoring compound derived from garlic, is considered to have cancer chemopreventive potential in experimental animals and humans. This study was designated to examine possible chemopreventive effects of DAS on colon carcinogenesis using genetically engineered transgenic ApcMin/⁺ mice, a well-established animal model for familial adenomatous polyposis (FAP) and sporadic colorectal cancer. Male C57BL/6J-ApcMin/⁺ mice were divided into three groups. Animals of group 1 were placed on the basal diet (AIN-76A) as non-treated controls. Animals of groups 2 and 3 were given DAS- containing diets (in doses of 100 and 300 ppm, respectively). All mice were sacrificed at the end of week 10 of the experiment. Histopathological investigation revealed that the incidence of colonic polyps was decreased dose-dependently by 19% (13/16) in group 2 and by 32% (13/20) in group 3 compared to the 100% incidence (10/10) in group 1. The multiplicity of colonic polyps per mouse was also slightly decreased by DAS treatment (1.88 ± 0.35 in group 2 and 1.63 ± 0.36 in group 3) compared to 2.00 ± 0.39 in group 1. On the other hand, there were no significant differences in the numbers of total polyps per mouse in the small intestine between the groups. Taken together, we suggest that DAS may exert promising inhibitory effects on colon carcinogenesis in the transgenic ApcMin/⁺ mice.

The possible chemopreventive effects of natural Egyptian flaxseed oil on preneoplasia and cancer formation were investigated in a rat medium-term colon carcinogenesis bioassay. Male Wistar rats were divided into 6 groups. Groups 1, 3 and 5 were initiated by 1,2-dimethylhydrazine (DMH) 20 mg/kg body weight s.c. 8 times, twice a week to initiate colon carcinogenesis. Groups 1 and 3 received 20% or 5% flaxseed oil respectively in diet in post initiation stage until the end. Groups 2 and 4 served as a flaxseed dose corresponding controls without carcinogen initiation, while rats in group 6 served as negative controls. Distribution and total numbers of aberrant crypt foci (ACF), putative preneoplastic lesions, particularly those with ≥4 aberrant crypts (ACs), and the numbers and sizes of colon tumors (adenoma and carcinoma) were significantly decreased by both treatment doses of flaxseeds as compared to group 5. Histochemical investigation revealed that the numbers of mucus-secreting cells in the colonic mucosa were reduced gradually during progression of colon carcinogenesis. Intriguingly, flaxseed oil caused the numbers and integrity of the mucus-secreting cells to retain close to normal levels and in a dose dependent manner. Moreover, the hematological parameters were almost constant between the groups particularly at the dose of 5% as compared to groups 5 and 6. PCNA-labeled indexes (PCNA-LI) in the DMH-initiated colonic mucosa were found to be decreased by both doses of flaxseeds administration. In conclusion, the present study showed that the post initiation dietary administration of flaxseeds oil suppressed DMH-induced colon carcinogenesis in rats without significant side effects. The mechanism is likely to be through its inhibitory effects on early cellular proliferation and modulation of mucin secretion properties in the initiated colonic mucosa.

Although lung cancer incidence rates and mortalities are still low in the Arab world as compared to Europe or USA, they is gradually increasing in the region. Furthermore, there is great variation between different parts of the Arab world. For instance, the age-standardized rates (ASRs) for lung cancer incidence are about 15 fold higher in Tunisia than in Sudan for men, and about 10 fold higher in Bahrain than in Yemen for females. Percentage data for both sexes of lung cancer in the Arab world show that 15/22 (68.1%) of the Arab countries have lung cancer as one of the most frequent five types of cancer. Despite major advances in understanding and treating cancer, the 5-year relative survival rate in North Africa and the Middle East is only 8%. With the notable exception of Algeria, and to a lesser extent Tunisia, where squamous cell carcinomas are more common, the two main types show approximately the same proportions in males, while adenocarcinomas tend to predominate in females.The estimated numbers of new lung cancer cases in 2008 were 9,537 in ages below 65 for both sexes, and 7,059 cases for ages above 65. In 2020 there is expected to be 14,788 new lung cancer cases in the Arab countries for ages below 65, and 14,788 cases for ages above 65 in both males and females. Between 1990 and 1997, cigarette consumption increased 24% in the Middle East, one of only two regions of the world where cigarette sales increased during that period, so that continued rise in cancer rates can be expected. Improvement of tobacco control, registration and treatment are all necessary to decrease the burden of lung cancer in the Arab world.

Nigella sativa (N. sativa) is a herbal plant of the Ranunculaceae family that has been widely used for various medicinal and nutritional purposes. Volatile oil extracts along with its major constituents, such as thymoquinone, have recently attracted considerable attention for their antioxidant, immunoprotective and antitumor properties. The present study was conducted to assess the chemopreventive potential of crude oils in N. sativa on tumor formation using a well-established rat multi-organ carcinogenesis model featuring initial treatment with five different carcinogens. Post-initiation administration of 1000 or 4000 ppm N. sativa volatile oil in the diet of male Wistar rats for 30 weeks significantly reduced malignant and benign colon tumor sizes, incidences and multiplicities. The treatment also significantly decreased the incidences and multiplicities of tumors in the lungs and in different parts of the alimentary canal, particularly the esophagus and forestomach. Bromodeoxyuridine labeling indices, reflecting cell proliferation were significantly decreased in various organs and lesions after treatment with the two doses of N. sativa. The plasma levels of insulin growth factor, triglycerides and prostaglandin E2 were also altered. The findings show, for the first time, that N. sativa administration exerts potent inhibitory effects on rat tumor development and on cellular proliferation in multiple organ sites. In particular, the ability to significantly inhibit murine colon, lung, esophageal and forestomach tumors was demonstrated in the post-initiation phase, with no evidence of clinical side effects. The mechanisms are likely to be related to suppression of cell proliferation.

South-West Asia, stretching from Lebanon and Syria in the north, through to Yemen in the south and Iraq in the east, is the home of more than 250 million people. Cancer is already a major problem and the markedly increasing rates for diabetes suggest that the burden of adenocarcinomas will only become heavier over time, especially with increasing obesity and aging of what are now still youthful populations. The age-distributions of the affected patients in fact might also indicate cohort effects in many cases. There are a number of active registries in the region and population-based data are now available for a considerable number of countries. Scientists from the region are also contributing to epidemiological research into the causes of cancer and how to develop effective control programs. The present review covers the relevant PubMed literature and cancer incidence data from various sources, highlighting similarities and variation in the different cancer types, with attempts to explain disparities with reference to environmental factors. In males, the most prevalent cancers vary, with lung urinary bladder or liver in first place, while for females throughout the region breast cancer is the major problem. In both sexes, non-Hodgkins lymphomas and leukemias are relatively prevalent, along with lung in males and thyroid in certain female populations. Coordination of activities within the Arab world, as well as Israel, could bring major benefits to cancer control in the eastern Mediterranean region.

The Arab world, stretching from Lebanon and Syria in the north, through to Morocco in the west, Yemen in the south and Iraq in the east, is the home of more than 300 million people. Cancer is already a major problem and the lifestyle changes underlying the markedly increasing rates for diabetes mean that the burden of neoplasia will only become heavier over time, especially with increasing obesity and aging of what are now still youthful populations. The age-distributions of the affected patients in fact might also indicate cohort effects in many cases. There are a number of active registries in the region and population-based data are now available for a considerable number of countries. A body of Arab scientists is also contributing to epidemiological research into the causes of cancer and how to develop effective control programs. The present review covers the relevant PubMed literature and cancer incidence data from various sources, highlighting similarities and variation in the different cancer types, with attempts to explain disparities with reference to possible environmental factors. In males, the most prevalent cancers vary, with lung, urinary bladder or liver in first place, while for females throughout the region breast cancer is the greatest problem. In both sexes, non-Hodgkins lymphomas and leukemias are relatively frequent, along with thyroid cancer in certain female populations. Adenocarcinomas of the breast, prostate and colorectum appear to be increasing. Coordination of activities within the Arab world could bring major benefits to cancer control in the eastern Mediterranean region.

To cast light on mechanisms underlying development of urothelial carcinomas (UCs) of the urinary bladder associated with Schistosomiasis, we immunohistochemically analyzed the relationship between oxidative stress markers, DNA single strand breaks (ssDNA) which could also measure the levels of base damage and apoptosis in DNA, and expression of DNA repair genes with levels of nitric oxide synthases in bladder carcinomas of Egyptian patients with or without Schistosoma hematobium infection. Marked elevation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels was found in squamous cell carcinomas and UCs associated with Schistosomiasis when compared with non-Schistosomal carcinomas. This was accompanied by strong over expression of the DNA-repair genes, 8-oxoguanine-DNA-glycosylase and apurinic/apyrimidinic endonuclease, as well as increased formation levels of ssDNA. Expression levels of inducible nitric oxide synthase (iNOS) which is known to be indirectly related to oxidative stress was higher in Schistosomal than in the non-Schistosomal carcinomas. However, expression of endothelial nitric oxide synthase was slightly stronger in non-Schistosomal than in the Schistosomal carcinomas. In conclusion, these findings suggest a strong correlation between Schistosoma haematobium infection and increased levels of oxidative stress accompanied by a continuous DNA damage and repair in UCs, all directly correlating with elevated iNOS.

The present study was designated to evaluate the effect of direct current induced permanent magnetic field (DC-MF) on chemically induced rat colon carcinogenesis. Five experimental groups of male S.D. rats were injected with 1,2-dimethylhydrazine (DMH) subcutaneously, 20 mg/kg b.wt., once a week for four weeks, with exposure to 1 mT DC-MF (12 hours/day) as follows: Before (pre) the carcinogen administration (group 1), simultaneously (group 2), after (post) the carcinogen administration (group 3) and daily from the beginning to the end of the experiment after 12 weeks (group 4). Rats of group 5 served as carcinogen-only treated controls while those of group 6 were non-treated controls. There were no differences in the incidences and multiplicities of colonic aberrant crypt foci (ACF), putative preneoplastic lesions, among all groups except that large foci in group 1 were significantly fewer in numbers than those found in group 5. Proliferating cell nuclear antigen labeling indexes (PCNA-LI) in the colon epithelium were essentially the same in MF-treated and control rats. Histopathological examination showed evident hemorrhage in the pituitary glands of some rats of groups 1-3, and in most rats of group 4. Transmission electron microscopy also revealed ultrastructural changes, but DNA ploidy analysis revealed no carcinogenicity to MF-exposed pituitary glands. Serum levels of AST, ALT, total protein, creatinine, albumin, albumin/globulin ratio and growth hormone levels did not change among the groups. The present study revealed that the action of an artificial MF on rats is not carcinogenic/or cancer-promoting, at least in the present protocol for colon carcinogenesis.

Dietary toxicity of mastic gum, a natural food additive, was studied in male and female F344 rats fed 0%, 0.22%, 0.67% and 2% levels mixed into powdered basal diet for 13 weeks. No mortality or obvious clinical signs were observed in any of the animals throughout the experimental period. Body weights were significantly reduced in the high dose-treated group from week 2 to the end of the experiment in males, and at weeks 8 and 13 in females. There were increased absolute and relative liver weights in a dose-related manner or limited to the high dose group males or females, along with changes in hematological parameters, including increased WBC and platelet in high dose males. Altered serum biochemistry parameters included increases of total proteins, albumin, and total cholesterol in both sexes, and gamma-GTP in females only. However, macroscopic examination at necropsy revealed no gross lesions, and microscopic examination also revealed no treatment-related findings in any organs examined. As dietary treatment of mastic gum for 13 weeks in the present study caused decreased body weights at the high dose, especially in males, and increased liver weights in a dose-related manner in both genders without any morphological findings, it is concluded that the administration of it has a no observed adverse effect level (NOAEL) of 0.67% in the diet.

Phenobarbital (PB), a rodent non-genotoxic carcinogen, showed hormesis, biphasic effects on rat liver carcinogenesis. To test the hypothesis that the hormesis earlier observed for PB induced hepatocarcinogenesis might also exist in the TGF-alpha transgenic mice model, one which is highly susceptible to carcinogenesis, the carcinogenic or promotion effects of a wide range of phenobarbital (PB) concentrations were investigated. Two weeks after a single i.p. dose of 5 mg /kg bw of diethylnitrosamine (DEN) to 15 day old mice, animals were treated with diet containing PB at doses of 0, 2, 15 or 500 ppm. The incidence and multiplicity of tumors, including hepatocellular adenomas and carcinomas, were significantly increased by the high dose of PB, but no significant difference among the groups receiving 2 and 15 ppm for liver tumors when compared to DEN alone group. The proliferating cell nuclear antigen indices for liver tumors and surrounding hepatocytes in high dose PB treated mice were significantly increased, but no change was noted at the lower doses. The total cytochrome P450 content in the liver was also elevated by 500 ppm of PB, while hepatic 8-OHdG levels demonstrated no significant change. In conclusion, PB at high dose enhances DEN-induced hepatocarcinogenesis in TGF-alpha transgenic mice, but low doses lack any significant effects. One possible mechanism of phenobarbital carcinogenicity might be influenced by cytochrome P450 system exhibiting a strong promoting activity for liver of mice.

Epidemiological studies indicated that human arsenic exposure can induce urinary bladder cancer. Methylation of inorganic arsenic can generate more reactive and toxic organic arsenical species. In this regard, it was recently reported that the methylated arsenical metabolite, dimethylarsinic acid [DMA(V)], induced urinary bladder tumors in rats. However, other methylated metabolites, like monomethylarsonic acid [MMA(V)] and trimethylarsine oxide (TMAO) were not carcinogenic to the urinary bladder. In order to compare the early effects of DMA(V), MMA(V), and TMAO on the urinary bladder transitional cell epithelium at the scanning electron microscope (SEM) level, we investigated the sub-chronic (13 weeks) toxicological effects of MMA(V) (187 ppm), DMA(V) (184 ppm), TMAO (182 ppm) given in the drinking water to male and female F344 rats with a focus on the urinary bladder in this study. Obvious pathological changes, including ropy microridges, pitting, increased separation of epithelial cells, exfoliation, and necrosis, were found in the urinary bladders of both sexes, but particularly in females receiving carcinogenic doses of DMA(V). Urine arsenical metabolic differences were found between males and females, with levels of MMA(III), a potential genotoxic form, higher in females treated with DMA(V) than in males. Thus, this study provides clear evidence that DMA(V) is more toxic to the female urinary bladder, in accord with sensitivity to carcinogenesis. Important gender-related metabolic differences including enhanced presentation of MMA(III) to the urothelial cells might possibly account for heightened sensitivity in females. However, the potential carcinogenic effects of MMA(III) need to be further elucidated.

Potential inhibitory effects of the antiangiogenic drug TNP-470 on rat urinary bladder carcinogenesis were investigated in F344 male rats initiated with 0.05% BBN in the drinking water for 8 weeks. Group 1 was then continuously treated with TNP-470 by subcutaneous injection using osmotic minipump until the end of the experiment; group 2 served as the control with only initiation. The incidences and multiplicities of papillomas and carcinomas in the TNP-470-treated group were significantly decreased compared to the control group values along with the tumor vascular density. In conclusion, TNP-470 can inhibit rat urinary bladder carcinogenesis, presumably through its effects on angiogenesis.

Objectives: It was the aim of this study to determine whether level IIB lymph nodes can be saved in elective neck dissection as a treatment for patients with squamous cell carcinoma (SCC) of the larynx. We present a prospective analysis of a case series., Methods: Thirty-one patients with SCC of the larynx and without palpable lymph nodes at the neck who underwent an elective neck dissection were prospectively studied. The incidence of micrometastasis to level IIB lymph nodes after performing elective neck dissection was evaluated by nested reverse transcription polymerase chain reaction for cytokeratin (CK)19 and CK20 as well as by pathological examination., Results: Nested reverse transcription polymerase chain reaction for CK19 and CK20 mRNA presented similar results but differed from the pathological examination. Of the 31 patients, 6 (19%) by pathological analysis and 9 (29%) by molecular analysis had lymph nodes positive for metastatic SCC. By molecular analysis, only 1 of the 31 patients had involvement of level IIB lymph nodes., Conclusions: This region may be preserved in elective neck dissection in patients with SCC of the larynx, so that accessory nerve dysfunction can be minimized and operative time can be saved., (Copyright 2006 S. Karger AG, Basel)

For the last 25 years, Prof. Nobuyuki Ito and his laboratory have focused on the development of liver medium-term bioassay system for detection of carcinogens in F344 rats utilizing glutathione S-transferase placental form (GST-P)-positive foci as an end point marker. In this presentation, the outline and samples of medium-term bioassay systems were described. Furthermore, our data demonstrated the presence of a threshold for the non-genotoxic carcinogen, phenobarbital (PB), and the lack of linearity in the low-dose area of the dose-response curve, providing evidence for hormesis. In addition, the establishment and applications of multiorgan carcinogenicity bioassay (DMBDD model), used for the examination of the carcinogenicity of genotoxic and non-genotoxic chemicals, are discussed. Dimethylarsinic acid, one of organic arsenics, was found to be carcinogenic in rat bladder using DMBDD model and carcinogenicity test.

2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), an abundant food-derived heterocyclic amine (HCA), has attracted particular attention as a human colon carcinogen. Humans are in fact exposed to continuous low doses of HCAs during lifetime. Therefore, we focused on rat large intestinal carcinogenicity of PhIP at levels that mimic practical human exposure. A total of 192 6-week-old male F344 rats were subcutaneously injected twice with 15 mg/kg body weight azoxymethane (AOM), then continuously fed various doses (0, 0.001, 0.01, 0.1, 1, 10, 50 and 200 ppm) of PhIP in the diet. At week 16, aberrant crypt foci (ACF) were quantitatively analyzed. At week 36, tumor occurrence was pathologically analyzed. Then immunohistochemical examinations were performed. PhIP was found to enhance strongly AOM-initiated rat large intestinal tumorigenesis at high doses (50 and 200 ppm), while lower doses (0.001-10 ppm) had no apparent effects. High doses also caused variation in tumor histologic types and their distribution throughout the large intestinal segments. Frequencies of ACF/cm(2) did not meaningfully vary between the groups. Cellular proliferation activity in normal-appearing colonic mucosa was significantly increased at high doses. These novel findings may provide evidence of a low-dose potential for PhIP, with a no-observed effect level speculated to be 10 ppm in the present initiation-promotion experimental model., (Copyright 2005 Wiley-Liss, Inc.)

As part of an investigation on the role of estrogen in liver disease, we tested the effects of estradiol-3-benzoate (EB) in the thioacetamide (TAA)-induced rat liver cirrhosis model. Male F344 rats (n = 100) were divided into six groups. Animals of groups 1-4 received TAA (0.03% in drinking water) for 12 weeks, and groups 5 and 6 served as controls without TAA. For the exposure period, EB pellets were implanted subcutaneously to give doses of 0 (groups 1 and 5), 1 (group 2), 10 (group 3), and 100 mug (groups 4 and 6) simultaneously. All animals were sacrificed at week 12. Significant increase of liver cirrhosis, liver weight, collagen content, and lipid peroxidation in the livers was evident in groups 3 and 4 (p < 0.05) compared with group 1. Formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) was significantly elevated in group 4 (p < 0.01), along with expression of alpha-smooth muscle actin (alpha-SMA) and stellate cell activation-associated protein (STAP), as determined by RT-PCR analysis (p < 0.01). However, there were no differences in liver weight, collagen content, lipid peroxidation, 8-OHdG formation, and alpha-SMA and STAP mRNA expression between groups 5 and 6. We conclude that EB treatment enhances TAA-induced cirrhosis, associated with increase of oxidative stress and activation of hepatic stellate cells.

We have previously demonstrated that JTE-522, a selective cyclooxygenase-2 (COX-2) inhibitor, inhibited development of aberrant crypt foci (ACF) in rats, a putative preneoplastic lesion in colon, and suggested its inhibitory potential in rat colon carcinogenesis. To evaluate the chemopreventive properties of JTE-522, the present study was design to evaluate the inhibitory effects of JTE-522 on rat colon tumorigenesis induced by 1,2-dimethylhydrazine (DMH). Rats at 6 weeks of age were divided into 4 groups. One week after the start of the experiment, all rats received DMH by s.c. injection at a dose of 40 mg/kg body weight once a week for 4 successive weeks. As the initiation and postinitiation treatment groups, groups 1-3 were fed diets containing 0, 50, or 150 ppm JTE-522, respectively, from the start of the study to the end. As the postinitiation treatment group, group 4 was given 150 ppm JTE-522 from 1 week after the last DMH injection to the end of the study. Forty weeks after the start of the experiment, administration of 150 ppm JTE-522 during both initiation and postinitiation stages significantly inhibited the incidences of tubular adenocarcinomas and total carcinomas, as well as total tumors in the colon. The inhibitory effect of JTE-522 was most prominent for tubular adenocarcinomas, but was not observed in the nontubular carcinomas (signet-ring cell and mucinous carcinomas). Almost equal inhibitory effects on tubular adenocarcinomas were also observed in the rats given 150 ppm JTE-522 during the postinitiation stage, suggesting that its major anticancer action is at the postinitiation phase. However, JTE-522 had no effect on the size or invasive extent of tubular adenocarcinomas. Furthermore, microarray analyses revealed that JTE-522 had no effect on gene expression levels in DMH-induced tubular adenocarcinomas. These findings suggest that JTE-522 possesses chemopreventive activity against induction but not progression of tubular adenocarcinomas in rat colon. In view of the significant inhibitory effects of JTE-522 on ACF, its major anticancer action may occur in the postinitiation stage but before the malignant conversion stage of DMH-induced colon carcinogenesis.

This study was carried out to achieve pathological understanding for the persistence of cirrhosis induced by thioacetamide (TAA). Forty-five, male,21-day-old, F344 rats were randomly allocated to group I and received drinking water as a control, and groups 2 and 3 given 0.015% or 0.03%TAA, respectively for 12 weeks. Two-third of animals per group were sacrificed, and remainder were maintained for a further 4 weeks without TAA treatment. Liver cirrhosis was induced in all animals in group 3 at week 12, with obvious increase of collagen content, and this persisted after cessation of TAA. Proliferating cell nuclear antigen (PCNA) positive labeling indices of nonparenchymal cells were increased significantly after cessation in groups 2 and 3 (p < 0.01). RT-RCR analysis of a-smooth muscle actin (alpha-SMA) showed significant increase in group 3 compared to that of control at both time points (p < 0.05). Immunohistochemical staining of it demonstrated positive cells to mainly be located around regenerating hepatic nodules at week 12, however, they were focused into enlarged portal areas consisting of fibrous tissues and pseudo-bile ductular cells after the cessation. Taken together, we conclude persistence of liver cirrhosis could be associated with the proliferation of nonparenchymal cells and altered location of alpha-SMA positive cells.

The present study was conducted to evaluate the potential carcinogenicity of enzymatically modified isoquercitrin, administered in the diet at doses of 0.5% or 1.5% to groups of 50 male and female F344/DuCrj rats. Control males and females (50 rats each) were maintained on basal diet. Animals were observed for 104 weeks. There were no treatment-related clinical signs of toxicity in the treated groups. Body weights, feed consumption, survival rates and hematological findings for exposed rats of both sexes showed no variations among the groups. There was a slight but significant dose-dependent decrease in relative spleen weights in all treated groups, albeit with no histopathological variation. Overall histopathological evaluation of neoplasms and all tissues after 2 years showed that tumors developed in all groups including the controls. There was a non-significant tendency for increase in the incidence of pituitary gland adenomas in the high dose-treated females (45.5%) as compared to controls (27.7%), with a slight increase in hemorrhage incidences, but values for males were low and similar in both control and treated rats. There were no apparent effects of isoquercitrin on development of kidney neoplasms, hyperplasias or chronic nephropathy. Parathyroid adenomas or hyperplasias were found not affected by isoquercitrin treatment, and there were no differences in mammary gland fibroadenomas or hyperplasias between treated and control rats. Various tumors were found in other organs with no significant differences between the groups. In conclusion, under the conditions of this 2-year feeding experiment, no evidence was obtained of carcinogenicity of enzymatically modified isoquercitrin in male or female F344 rats.

Although numerous epidemiological studies have indicated that human arsenic exposure is associated with increased incidences of bladder, liver, skin, and lung cancers, limited attempts have been made to understand mechanisms of carcinogenicity using animal models. Dimethylarsinic acid (DMA), an organic arsenic compound, is a major metabolite of ingested inorganic arsenics in mammals. Recent in vitro studies have proven DMA to be a potent clastogenic agent, capable of inducing DNA damage including double strand breaks and cross-link formation. In our attempts to clarify DMA carcinogenicity, we have recently shown carcinogenic effects of DMA and its related metabolites using various experimental protocols in rats and mice: (1) a multi-organ promotion bioassay in rats; (2) a two-stage promotion bioassay by DMA of rat urinary bladder and liver carcinogenesis; (3) a 2-year carcinogenicity test of DMA in rats; (4) studies on the effects of DMA on lung carcinogenesis in rats; (5) promotion of skin carcinogenesis by DMA in keratin (K6)/ornithine decarboxylase (ODC) transgenic mice; (6) carcinogenicity of DMA in p53(+/-) knockout and Mmh/8-OXOG-DNA glycolase (OGG1) mutant mice; (7) promoting effects of DMA and related organic arsenicals in rat liver; (8) promoting effects of DMA and related organic arsenicals in a rat multi-organ carcinogenesis test; and (9) 2-year carcinogenicity tests of monomethylarsonic acid (MMA) and trimethylarsine oxide (TMAO) in rats. The results revealed that the adverse effects of arsenic occurred either by promoting and initiating carcinogenesis. These data, as covered in the present review, suggest that several mechanisms may be involved in arsenic carcinogenesis.

Prostaglandin E2, which is produced by cyclooxygenase (COX) during arachidonic acid metabolism, is considered to be related to colon carcinogenesis and selective COX-2 inhibitors may be effective for chemoprevention without the adverse side effects of non-selective, nonsteroid anti-inflammatory drugs. Therefore, the influence of JTE-522 (4-(4-cyclohexyl-2-methyloxazol-5-yl)-2-fluorobenzensulfonamide), a selective COX-2 inhibitor, was examined in azoxymethane(AOM)-induced rat colon carcinogenesis. A total of 40 male F344 rats were randomly divided into two groups. Group 1 received diet containing 0.015% JTE-522 and group 2 the normal diet without supplement as a control group; one week later, all rats were administered axozymethane (AOM) s.c. at a dose of 15 mg/kg body weight once a week for 3 successive weeks. At the termination of the experiment (30 weeks after the start), the multiplicity of colon cancer in group 1 was significantly less than that of group 2. The proliferating cell nuclear antigen (PCNA) indices for non-neoplastic cells of the colon mucosa in group 1 were also lower. These data thus suggest that JTE-522 has chemopreventive potential against colon carcinogenesis with decrease of mucosal cell proliferation in rats.

After the Chernobyl accident in 1986, the incidence of urinary bladder cancers in the Ukraine increased gradually from 26.2 to 43.3 per 100,000 people between 1986 and 2001. In the areas of low level but persistent cesium-137 (137Cs) radio-contamination, a unique atypical radiation-related urinary bladder cystitis named 'Chernobyl cystitis', a possible pre-neoplastic condition in humans, has been detected. We have previously documented high incidences of bladder lesions, including severe dysplasias and/or carcinoma in situ, in association with this cystitis and correlating with oxidative DNA damage. To further investigate the molecular mechanisms underlying bladder carcinogenesis with this specific etiology, mutation analysis of p53 gene (exon 5-8) was performed for 11 and 18 paraffin-embedded bladder cancers in Ukrainians, respectively collected before and after the Chernobyl disaster. DNAs were extracted and subjected to nested PCR-single-strand conformational polymorphism analysis followed by direct DNA sequencing, as well as p53 immunohistochemistry (IHC). The incidences of p53 gene mutation were 54.5 and 16.7% for before and after the Chernobyl disaster, respectively, the difference being statistically significant. Also a tendency for higher p53 IHC score was apparent in the earlier group of lesions. No significant difference was noted for the proportions of historical types. These results point to possible distinct molecular carcinogenic pathways of bladder cancer formation, before and after the Chernobyl disaster, on the basis of variation in p53 gene alteration.

The DMBDD rat multi-organ carcinogenesis model based on two-stage carcinogenesis theory was revised to make more suitable assay system for detecting chemopreventive effects of chemical substances by increasing the doses of two carcinogens, 1,2-dimethylhydrazine dihydrochloride (DMH) and N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN). The revised bioassay resulted in increasing preneoplastic or neoplastic lesions in the colon, urinary bladder and liver. S-Methylcysteine (SMC), a water-soluble organosulfur compound, was used as a test chemical in the new initiation regimen. Though SMC did not express clear-cut inhibitory effects in tumor levels, it showed modifying effects on the development of lung hyperplastic and colon preneoplastic lesions. In conclusion, the present model featuring high yields of preneoplastic and neoplastic lesions with low mortality in a short period (30 weeks), might be suitable for testing the efficacy of possible chemopreventive chemicals at the whole-body level.

Background: The efficacy of FK228, a histone deacetylase inhibitor that is currently under early clinical trials for cancer therapy, against N-butyl-N-(4-hydroxybutyl)- nitrosamine (BBN) -induced mouse urinary bladder carcinogenesis was examined., Materials and Methods: Heterozygous p53-deficient (p53+/-) and wild-type (p53+/+) mice were given FK228 (0, 0.01 and 0.1 mg/kg i.p., 3 times/week, respectively) after 10 weeks of 0.05% BBN treatment, and were sacrificed at 22 and 24 weeks after the start, respectively., Results: There was no significant difference in the incidence of urinary bladder tumors among groups in the p53+/- or p53+/+ mice, although the high dose of FK228 increased the p21WAF1 mRNA expression in urinary bladder cancers in animals of both genotypes., Conclusion: The present data indicate a lack of any inhibitory effects of FK228 on BBN-induced mouse urinary bladder carcinogenesis under the present conditions.