Development Of Preneoplastic Lesions Research Articles

Dietary inclusion of cyanobacteria Arthrospira (Spirulina platensis) spp. decreases the aggravating effect of hemin from red meat in a rat colorectal carcinogenesis model

Colorectal cancer (CRC) risk, associated with a high intake of red/processed meat, may be related to hemin. A potential chemopreventive agent, Arthrospira (Spirulina platensis) spp. (AP) is a cyanobacteria employed as a functional food with the potential to reduce malnutrition in developing countries. Thus, we assessed the effects of dietary AP against hemin-promoting effects in a dimethylhydrazine (DMH)-induced colorectal carcinogenesis model. Male Sprague-Dawley rats were allocated into five groups. G1–G4 received four subcutaneous DMH injections (40 mg/kg body weight, twice a week for 2 weeks) and G5 received DMH vehicle. At weeks 4 to 16, groups were fed a balanced diet (BD, G1 and G5), BD containing 2 % AP (20 g powder/kg chow, G2), BD containing hemin (0.32 g/kg chow, G3) or BD containing hemin+2 % AP (G4), respectively. Hemin group (G3) increased aberrant crypt foci (ACF) development, malondialdehyde (MDA), and Nox-1 levels and reduced glutathione (GSH) and GSH-Px levels in colonic mucosa when compared to DMH group (G1). In contrast, the dietary hemin+2 % AP regimen (G4), reduced both preneoplastic lesion development and MDA levels while increased GSH levels, compared to the DMH+hemin group (G3). Dietary AP may reduce hemin-promoting effects by modulating oxidative stress and ACF lesions.

Single nucleotide polymorphism rs4961 in the adducin 1 gene is not associated with gastric cancer or preneoplastic cancer lesions.

Gastric cancer (GC) is the fourth most deadly cancer globally. The adducin 1 (ADD1) protein is involved in oncogenic signal transduction pathways in several types of cancer, and the rs4961 variant (c.1378 G>T, p.Gly460Trp) of the ADD1 gene is associated with salt-sensitive hypertension, renal cell cancer and breast cancer susceptibility; however, it has not been investigated in GC. The aim of the present study was to evaluate the association between the rs4961 variant and the development of GC and preneoplastic gastric lesions (PGLs) in a population from western Mexico. A total of 225 individuals who underwent an endoscopy were evaluated, of which 71 patients had histopathologically diagnosed GC and 53 patients had PGLs, with 101 patients used as controls. The rs4961 variant was genotyped by using PCR and DNA sequencing. The frequency of the mutated homozygous genotype (TT) of the rs4961 variant was <10% in the three evaluated groups, and the frequency of the minor allele (T) was <21% in the GC, PGL and control groups. Genotypic and allelic frequencies were similarly distributed in all of the studied groups (P>0.05). In summary, in the study population, the rs4961 variant was not associated with GC risk; however, its role in other populations and in other types of cancer is worthy of future research.

Cancer Chemopreventive Effect of 2',4'-Dihydroxy-6'-methoxy-3',5'-dimethylchalcone on Diethylnitrosamine-Induced Early Stages of Hepatocarcinogenesis in Rats.

2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC) is a major compound in Cleistocalyx nervosum seed extract (CSE), which has been reported to have various biological activities, including anti-cancer activity. Therefore, this study attempted to evaluate whether DMC is a chemopreventive compound in CSE. Moreover, the preventive mechanisms of CSE and DMC in the DEN-induced early stages of hepatocarcinogenesis in rats were investigated. Male Wistar rats were intraperitoneally injected with DEN 50 mg/kg bw once a week for 8 weeks. Rats received CSE and DMC orally throughout the experiment. The number of glutathione S-transferase placental form (GST-P)-positive foci in the liver was measured. Furthermore, the preventive mechanisms of CSE and DMC on DEN-induced HCC, including cell proliferation and apoptosis, were investigated. Administering CSE at a dosage of 400 mg/kg bw and DMC at a dosage of 10 mg/kg bw significantly decreased the number and size of GST-P-positive foci and GST-P expression. In addition, DMC inhibited the development of preneoplastic lesions by decreasing cell proliferation and causing cell apoptosis; however, CSE inhibited the development of preneoplastic lesions by inducing cell apoptosis. In conclusion, DMC exhibited a cancer chemopreventive effect on the early stages of hepatocarcinogenesis by increasing cell apoptosis and reducing cell proliferation.

NFS-09.NF1 MUTATION IN OLIGODENDROCYTE PRECURSOR CELLS LEADS TO PRENEOPLASTIC LESION FORMATION IN THE BRAIN

Abstract Oligodendrocyte precursor cells (OPCs) are progenitor cells that give rise to central nervous system oligodendrocytes throughout life. Transcriptomic and lineage tracing studies suggest that OPCs may be the putative cell of origin for many glioma histologic subtypes. While children with the neurofibromatosis type 1 (NF1) cancer predisposition syndrome are prone to low-grade gliomas following bi-allelic NF1 loss, the cellular and molecular etiologies underlying tumorigenesis remain incompletely elucidated. Using a unique collection of genetically engineered Nf1 mouse strains, we identified discrete hyperdense lesions composed of OPCs. The OPCs within the lesions display a transient increase in proliferation and hypercellularity (hyperplasia). This phenotype was not observed following heterozygous mutation in other tumor suppressors (Trp53, Pten, or Rb1). OPC-specific heterozygous Nf1-mutant mice harbored similar lesions, suggesting an OPC-intrinsic phenotype. OPC-specific Nf1 loss resulted in increased OPC density throughout the entire brain, suggesting that the lesions in heterozygous Nf1-mutant mice represent spontaneous OPC Nf1 loss-of-heterozygosity events. Mechanistically, monoallelic KRAS hyperactivation phenocopies OPC hyperdensities in the brain of Nf1+/- mice; however, KRAS hyperactivity is not necessary for lesion formation or expansion. When the brains of mice engineered with heterozygous NF1 patient-derived Nf1 mutations were examined, the development of hyperdense OPC lesions reflected RAS-independent dysregulated PI3K-AKT signaling. Collectively, our study reveals a potential mechanism driving the development of preneoplastic lesions in the brains of individuals with NF1.

Molecular mechanisms of human papilloma virus related skin cancers: A review.

The human papillomavirus (HPV) belongs to the Papillomaviridae family of viruses which includes small, double-stranded DNA viral agents. Approximately 90% of HPV infections occur asymptomatically and resolve spontaneously. However, infection with high-risk viral strains can lead to the development of preneoplastic lesions, with an increased propensity to become cancerous. The location of these malignancies includes the oral cavity, cervix, vagina, anus, and vulva, among others. The role of HPV in carcinogenesis has already been demonstrated for the aforementioned neoplasia. However, regarding skin malignancies, the mechanisms that pinpoint the role played by HPV in their initiation and progression still elude our sight. Until now, the only fully understood mechanism of viral cutaneous oncogenesis is that of human herpes virus 8 infection in Kaposi sarcoma. In the case of HPV infection, however, most data focus on the role that beta strains exhibit in the oncogenesis of cutaneous squamous cell carcinoma (cSCC), along with ultraviolet radiation (UVR) and other environmental or genetic factors. However, recent epidemiological investigations have highlighted that HPV could also trigger the onset of other non-melanocytic, for example, basal cell carcinoma (BCC), and/or melanocytic skin cancers, for example, melanoma. Herein, we provide an overview of the role played by HPV in benign and malignant skin lesions with a particular focus on the main epidemiological, pathophysiological, and molecular aspects delineating the involvement of HPV in skin cancers.

Proteins Involved in Focal Cell Adhesion and Podosome Formation Are Differentially Expressed during Colorectal Tumorigenesis in AOM-Treated Rats.

Colorectal tumorigenesis involves the development of aberrant crypt foci (ACF) or preneoplastic lesions, representing the earliest morphological lesion visible in colon cancer. The purpose of this study was to determine changes in protein expression in carcinogen-induced ACF as they mature and transform into adenomas. Protein expression profiles of azoxymethane (AOM)-induced F344 rat colon ACF and adenomas were compared at four time points, 4 (control), 8, 16, and 24 weeks post AOM administration (n = 9/group), with time points correlating with induction and transformation events. At each time point, micro-dissected ACF and/or adenoma tissues were analyzed across multiple quantitative two-dimensional (2D-DIGE) gels using a Cy-dye labeling technique and a pooled internal standard to quantify expression changes with statistical confidence. Western blot and subsequent network pathway mapping were used to confirm and elucidate differentially expressed (p ≤ 0.05) proteins, including changes in vinculin (Vcl; p = 0.007), scinderin (Scin; p = 0.02), and profilin (Pfn1; p = 0.01), By determining protein expression changes in ACF as they mature and transform into adenomas, a "baseline" of altered regulatory proteins associated with adenocarcinoma development in this model has been elucidated. These data will enable future studies aimed at biomarker identification and understanding the molecular biology of intestinal tumorigenesis and adenocarcinoma maturation under varying intestinal conditions.

Potential therapeutic and apoptotic impact of ginger and ginger nanoparticles against liver preneoplastic lesions development by inhibition of oncogenic miRNA-221 and initiation of Bcl-2/ caspase 3 signaling pathways

Potential therapeutic and apoptotic impact of ginger and ginger nanoparticles against liver preneoplastic lesions development by inhibition of oncogenic miRNA-221 and initiation of Bcl-2/ caspase 3 signaling pathways

End-stage kidney disease: a never healing wound leading to another never healing wound, renal cancer

BackgroundEnd-stage kidney disease and acquired cystic kidney disease are the final stages of chronic kidney disease, leading to loss of kidney function and frequent development of tumours. It has been suggested that an inflammatory microenvironment may be responsible for the progressive kidney remodelling and cancer development.MethodsOur aim was to analyse gene expression suggested to be involved in the remodelling of kidneys in end-stage kidney disease, and in the development of preneoplastic lesions and tumours. Immunohistochemistry was employed to assess the cellular localisation of different genes involved in these pathways on representative tissue sections.ResultsCellular (αSMA positive naïve activated fibroblasts, endothelial cells, macrophages) and non-cellular components (cytokines IL6, TGFβ, IL1β, CSF2, fibronectin, laminin, and matrix modifier proteases MMP9 and MMP12) of the inflammatory microenvironment were expressed in the kidneys of patients with end-stage kidney disease. IL6 and FN1 expressing naïve activated fibroblasts and recruited inflammatory cells were the most abundant cellular components of the inflammatory microenvironment.ConclusionThe progressive inflammatory and fibrotic processes in end-stage kidney disease have features recalling those of a never healing wound and may explain the frequent development of kidney cancer.Graphical abstract

Učinci ekstrakta Cytinus hypocistis (L.) L. u životinjskom modelu neoplazije inducirane papiloma virusom

Infections with certain types of papillomavirus, such as the human papillomavirus 16 (HPV16), are associated with the development of preneoplastic lesions and cancers of the anogenital, and head and neck regions. Cytinus hypocistis (L.) L. extracts are composed of substances presenting antiproliferative, antioxidant, anti-inflammatory and antibacterial properties, which might be promising as new therapeuticcompounds. This study analysed the influence of topical application of an extract obtained from C. hypocistis (CH) on K14-HPV16 and FVB/n mice to evaluate its therapeutic and toxicological properties. To achieve the study goals,30 female mice, 33–37 weeks old, were divided into six groups (n=5/group): I (HPV+CH3.1); II (HPV+CH6.2); III (HPV+CH12.4); IV (FVB/n+CH12.4); V (HPV+control) and VI (FVB/n+-control). CH was applied topically to both ears for 28 days. After this period, all animals were sacrificed for samples collection. Skin lesions were classified histologically. Toxicological parameters included haematological and biochemical blood markers, and hepatic oxidative stress analysis. Transgenic animals showed a decrease in mean body weight regardless of the concentration of extract applied. The extract had no influence on physiological parameters, organ weight, or biochemical and oxidative stress parameters. Histology demonstrated the presence of proliferative epithelial lesions in the skin and oral mucosa of K14-HPV16 mice, with no association with the application of this extract. Overall, the application of CH extract had no influence on the skin lesions and was well tolerated by the animals in these concentrations.

Comprehensive Profiling of Early Neoplastic Gastric Microenvironment Modifications and Biodynamics in Impaired BMP-Signaling FoxL1+-Telocytes.

FoxL1+telocytes (TCFoxL1+) are novel gastrointestinal subepithelial cells that form a communication axis between the mesenchyme and epithelium. TCFoxL1+ are strategically positioned to be key contributors to the microenvironment through production and secretion of growth factors and extracellular matrix (ECM) proteins. In recent years, the alteration of the bone morphogenetic protein (BMP) signaling in TCFoxL1+ was demonstrated to trigger a toxic microenvironment with ECM remodeling that leads to the development of pre-neoplastic gastric lesions. However, a comprehensive analysis of variations in the ECM composition and its associated proteins in gastric neoplasia linked to TCFoxL1+ dysregulation has never been performed. This study provides a better understanding of how TCFoxL1+ defective BMP signaling participates in the gastric pre-neoplastic microenvironment. Using a proteomic approach, we determined the changes in the complete matrisome of BmpR1a△FoxL1+ and control mice, both in total antrum as well as in isolated mesenchyme-enriched antrum fractions. Comparative proteomic analysis revealed that the deconstruction of the gastric antrum led to a more comprehensive analysis of the ECM fraction of gastric tissues microenvironment. These results show that TCFoxL1+ are key members of the mesenchymal cell population and actively participate in the establishment of the matrisomic fraction of the microenvironment, thus influencing epithelial cell behavior.

Abstract 706: Efficacy evaluation of BR-9001, a SMEDDS formulation of 3,3’-diindolylmethane, as an inhibitor of preneoplastic and neoplastic lesion development in the prostate of Hi-Myc mice

Abstract Self-Microemulsifying Drug Delivery Systems (SMEDDS) can greatly increase the bioavailability of agents with limited solubility. Studies were performed to characterize the efficacy of BR-9001, a SMEDDS formulation of 3,3’-diindolylmethane (DIM), in preventing preneoplastic and neoplastic prostate lesion development in Hi-Myc mice. Beginning at age 8 weeks, groups of 105 male Hi-Myc mice received twice daily oral (gavage) administration of BR-9001 (BioResponse LLC, Boulder, CO) at DIM-equivalent doses of 0 (vehicle control), 200, or 400 mg/kg/dose. At ages 4 months, 5.5 months, and 7 months, cohorts of 35 mice/group were euthanized and necropsied; at each time point, tissues were collected from 25 mice/group for pathology; 5 mice/group for analysis of DIM levels in the plasma and prostate; and 5 mice/group for biomarker analysis. Prostate lesion development in pathology cohorts was determined by microscopic evaluation of step sections through the entire accessory sex gland block. Plasma and prostate levels of DIM were quantitated by LC-MS/MS; biomarkers were analyzed by RT-PCR. Administration of BR-9001 produced dose-related levels of DIM in the plasma and prostate at all time points. However, BR-9001 provided at most limited protection against prostate lesion development. Most lesions were identified in the lateral prostate (LP), where statistically significant reductions in incidences of murine prostatic intraepithelial neoplasias (mPIN) were seen in 4-month-old mice receiving the high dose of BR-9001 and in 5.5-month-old and 7-month-old mice receiving the low dose of BR-9001. Reductions in mPIN incidence in groups receiving BR-9001 were due to lower incidences of small mPIN lesions; incidences of large mPIN were significantly increased at 5.5 months in both groups receiving BR-9001. BR-9001 had no statistically significant effect on % occupancy of the LP by mPIN, the incidence of microinvasive mPIN in the LP, or cancer incidence in the LP. In the anterior prostate (AP), incidences of atypical hyperplasia were similar in all groups. However, at all necropsy time points, mice receiving the high dose of BR-9001 demonstrated significant increases in the incidences of moderate to marked AP atypia; these increases were accompanied by decreases in the incidence of mice with slight to moderate AP atypia. None of 22 potential molecular biomarkers were found to be clearly linked to development and progression of prostate lesions in Hi-Myc mice. Despite the presence of measurable concentrations of DIM in the plasma and prostate in mice in both treated groups at all time points, BR-9001 demonstrated equivocal efficacy in preventing the development of preneoplastic and neoplastic lesions in the Hi-Myc mouse model of prostate cancer. [Supported by NCI HHSN261201500042I/HHSN26100003.] Citation Format: Genoveva Murillo, Gina Qualter, Xinjian Peng, Miguel Muzzio, Elizabeth R. Glaze, Altaf Mohammed, Maarten C. Bosland, David L. McCormick. Efficacy evaluation of BR-9001, a SMEDDS formulation of 3,3’-diindolylmethane, as an inhibitor of preneoplastic and neoplastic lesion development in the prostate of Hi-Myc mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 706.

Nuclear GSK-3β and Oncogenic KRas Lead to the Retention of Pancreatic Ductal Progenitor Cells Phenotypically Similar to Those Seen in IPMN.

Glycogen synthase kinase-3β (GSK-3β) is a downstream target of oncogenic KRas and can accumulate in the nucleus in pancreatic ductal adenocarcinoma (PDA). To determine the interplay between oncogenic KRas and nuclear GSK-3β in PDA development, we generated Lox-STOP-Lox (LSL) nuclear-targeted GSK-3β animals and crossed them with LSL-KRasG12D mice under the control of the Pdx1-cre transgene—referred to as KNGC. Interestingly, 4-week-old KNGC animals show a profound loss of acinar cells, the expansion of ductal cells, and the rapid development of cystic-like lesions reminiscent of intraductal papillary mucinous neoplasm (IPMN). RNA-sequencing identified the expression of several ductal cell lineage genes including AQP5. Significantly, the Aqp5+ ductal cell pool was proliferative, phenotypically distinct from quiescent pancreatic ductal cells, and deletion of AQP5 limited expansion of the ductal pool. Aqp5 is also highly expressed in human IPMN along with GSK-3β highlighting the putative role of Aqp5+ ductal cells in human preneoplastic lesion development. Altogether, these data identify nGSK-3β and KRasG12D as an important signaling node promoting the retention of pancreatic ductal progenitor cells, which could be used to further characterize pancreatic ductal development as well as lineage biomarkers related to IPMN and PDA.

Targeting NAE1-mediated protein hyper-NEDDylation halts cholangiocarcinogenesis and impacts on tumor-stroma crosstalk in experimental models

Cholangiocarcinoma (CCA) comprises a heterogeneous group of malignant tumors associated with dismal prognosis. Alterations in post-translational modifications (PTMs), including NEDDylation, result in abnormal protein dynamics, cell disturbances and disease. Herein, we investigate the role of NEDDylation in CCA development and progression. Levels and functions of NEDDylation, together with response to pevonedistat (NEDDylation inhibitor) or CRISPR/Cas9 against NAE1 were evaluated invitro, invivo and/or in patients with CCA. The development of preneoplastic lesions in Nae1+/- mice was investigated using an oncogene-driven CCA model. The impact of NEDDylation in CCA cells on tumor-stroma crosstalk was assessed using CCA-derived cancer-associated fibroblasts (CAFs). Proteomic analyses were carried out by mass-spectrometry. The NEDDylation machinery was found overexpressed and overactivated in human CCA cells and tumors. Most NEDDylated proteins found upregulated in CCA cells, after NEDD8-immunoprecipitation and further proteomics, participate in the cell cycle, proliferation or survival. Genetic (CRISPR/Cas9-NAE1) and pharmacological (pevonedistat) inhibition of NEDDylation reduced CCA cell proliferation and impeded colony formation invitro. NEDDylation depletion (pevonedistat or Nae1+/- mice) halted tumorigenesis in subcutaneous, orthotopic, and oncogene-driven models of CCA invivo. Moreover, pevonedistat potentiated chemotherapy-induced cell death in CCA cells invitro. Mechanistically, impaired NEDDylation triggered the accumulation of both cullin RING ligase and NEDD8 substrates, inducing DNA damage and cell cycle arrest. Furthermore, impaired NEDDylation in CCA cells reduced the secretion of proteins involved in fibroblast activation, angiogenesis, and oncogenic pathways, ultimately hampering CAF proliferation and migration. Aberrant protein NEDDylation contributes to cholangiocarcinogenesis by promoting cell survival and proliferation. Moreover, NEDDylation impacts the CCA-stroma crosstalk. Inhibition of NEDDylation with pevonedistat may represent a potential therapeutic strategy for patients with CCA. Little is known about the role of post-translational modifications of proteins in cholangiocarcinoma development and progression. Herein, we show that protein NEDDylation is upregulated and hyperactivated in cholangiocarcinoma, promoting tumor growth. Pharmacological inhibition of NEDDylation halts cholangiocarcinogenesis and could be an effective therapeutic strategy to tackle these tumors.

Chemical Oral Cancerogenesis Is Impaired in PI3Kγ Knockout and Kinase-Dead Mice.

Simple SummaryOral carcinoma remains one of the most challenging cancers to be cured and the pharmacological approach is often ineffective. The identification of novel molecular targets will greatly improve its management. We wondered if PI3Kγ might be looked at as a target in oral cancer handling. In this preclinical study, we analyzed the role of PI3Kγ in a murine transgenic model. We demonstrated that the absence/inhibition of PI3Kγ might be a reasonable strategy to impair the development of preneoplastic and neoplastic lesions of the oral cavity. PI3Kγ is not required for normal development, life span, or basic immune responses, unless under stress conditions; therefore, low toxicity and few side effects are expected by acting on PI3Kγ as a therapeutic target.We investigated the role of PI3Kγ in oral carcinogenesis by using a murine model of oral squamous carcinoma generated by exposure to 4-nitroquinoline 1-oxide (4NQO) and the continuous human cancer cell line HSC-2 and Cal-27. PI3Kγ knockout (not expressing PI3Kγ), PI3Kγ kinase-dead (carrying a mutation in the PI3Kγ gene causing loss of kinase activity) and wild-type (WT) C57Bl/6 mice were administered 4NQO via drinking water to induce oral carcinomas. At sacrifice, lesions were histologically examined and stained for prognostic tumoral markers (EGFR, Neu, cKit, Ki67) and inflammatory infiltrate (CD3, CD4, CD8, CD19 and CD68). Prevalence and incidence of preneoplastic and exophytic lesions were significantly and similarly delayed in both transgenic mice versus the control. The expression of prognostic markers, as well as CD19+ and CD68+ cells, was higher in WT, while T lymphocytes were more abundant in tongues isolated from transgenic mice. HSC-2 and Cal-27 cells were cultured in the presence of the specific PI3Kγ-inhibitor (IPI-549) which significantly impaired cell vitality in a dose-dependent manner, as shown by the MTT test. Here, we highlighted two different mechanisms, namely the modulation of the tumor-infiltrating cells and the direct inhibition of cancer-cell proliferation, which might impair oral cancerogenesis in the absence/inhibition of PI3Kγ.

Beneficial effects of anthocyanin-rich peels of Myrtaceae fruits on chemically-induced liver fibrosis and carcinogenesis in mice

Hepatocellular carcinoma (HCC) arising from fibrosis/cirrhosis is the most common type of primary liver cancer. Conversely, a higher intake of fruits and vegetables might play a protective role in HCC risk. Recently, Myrtaceae family tropical fruits have raised great interest due to the high levels of anthocyanins especially in their peels, which are usually discarded upon consumption. Anthocyanins are antioxidant pigments known to have beneficial effects in vivo/in vitro cancer bioassays. Thus, we evaluated whether dietary Myrciaria jaboticaba, Syzygium cumini, and Syzygium malaccense fruit peel powders reduce fibrosis and hepatocarcinogenesis in mice. Female C3H/HeJ mice were submitted to the model of diethylnitrosamine/carbon tetrachloride-induced liver fibrosis and carcinogenesis. Concomitantly, mice received a basal diet containing 2% of M. jaboticaba, S. cumini, or S. malaccense fruit peel powders, obtained by convective drying, for 10 weeks. M. jaboticaba peel powder showed the highest levels of total anthocyanins, while S. cumini peel powder displayed the greatest diversity of these pigments. All Myrtaceae family peel powders reduced the serum levels of the liver injury marker alanine aminotransferase. M. jaboticaba peel feeding reduced the incidence of liver preneoplastic foci, hepatocyte proliferation (Ki-67), and the protein levels of hepato-mitogen tumor necrosis factor-alpha (TNF-α). M. jaboticaba peel feeding also diminished liver lipid peroxidation and increased total glutathione levels. S. cumini peel feeding reduced hepatic collagen, lipid peroxidation, and TNF-α levels while increased catalase activity. Although S. malaccense peel powder, which displayed the lowest anthocyanin levels, decreased oxidative stress, and cytokine levels, no effects were observed on liver fibrosis or preneoplastic lesion outcomes. Findings indicate a protective effect of anthocyanin-rich M. jaboticaba and S. cumini peel powder feeding on preneoplastic lesion development and fibrosis, respectively. Results indicate that differential biological responses may be attributed to distinct anthocyanin profiles and levels, assigning a functional/market value to the underutilized peel fraction.

Allopurinol Suppresses Azoxymethane-Induced Colorectal Tumorigenesis in C57BL/KsJ-db/db Mice

Obesity and related metabolic disorders, including chronic inflammation and enhanced oxidative stress, are closely associated with the development and progression of colorectal cancer. Previous epidemiological studies have demonstrated that increased serum uric acid is associated with the risk for various types of cancer, including colon cancer. This study examined the effects of a xanthine oxidase inhibitor allopurinol, widely used as a uric acid lowering medicine, on colorectal tumorigenesis in obese mice. Male C57BL/KsJ-db/db mice were injected with azoxymethane (15 mg/kg body weight) and then received drinking water containing allopurinol (30 mg/kg body weight) for fourteen weeks. At the time of sacrifice, allopurinol treatment significantly inhibited the development of colonic premalignant lesions. In the allopurinol-treated group, cellular proliferation in colonic mucosa was significantly suppressed, which was evaluated by the expression of proliferating cell nuclear antigen. Allopurinol also inhibited macrophage infiltration in the adipose tissue and decreased the serum level of TNF-α. The values of oxidative stress markers were markedly decreased in the allopurinol-treated group compared to those in the control group. These findings suggest that allopurinol attenuated chronic inflammation and decreased oxidative stress, preventing the development of colonic pre-neoplastic lesions in obesity-associated colon tumorigenesis model.

Synbiotic VSL#3 and yacon-based product modulate the intestinal microbiota and prevent the development of pre-neoplastic lesions in a colorectal carcinogenesis model.

Colorectal cancer is a public health problem, with dysbiosis being one of the risk factors due to its role in intestinal inflammation. Probiotics and synbiotics have been used in order to restore the microbiota balance and to prevent colorectal carcinogenesis. We aimed to investigate the effects of the probiotic VSL#3® alone or in combination with a yacon-based prebiotic concentrate on the microbiota modulation and its influence on colorectal carcinogenesis in an animal model. C57BL/6J mice were divided into three groups: control (control diet), probiotic (control diet + VSL#3®), and synbiotic (yacon diet + VSL#3®). The diets were provided for 13 weeks and, from the third one, all animals were subjected to induction of colorectal cancer precursor lesions. Stool samples were collected to evaluate organic acids, feces pH, β-glucuronidase activity, and microbiota composition. The colon was used to count pre-neoplastic lesions and to determine the cytokines. The microbiota composition was influenced by the use of probiotic and synbiotic. Modifications were also observed in the abundance of bacterial genera with respect to the control group, which confirms the interference of carcinogenesis in the microbiota. Pre-neoplastic lesions were reduced by the use of the synbiotic, but not with the probiotic. The protection provided by the synbiotic can be attributed to the modulation of the intestinal inflammatory response, to the inhibition of a pro-carcinogenic enzyme, and to the production of organic acids. The modulation of the composition and activity of the microbiota contributed to beneficial changes in the intestinal microenvironment, which led to a reduction in carcinogenesis. KEY POINTS: • Synbiotic reduces the incidence of colorectal cancer precursor lesions. • Synbiotic modulates the composition and activity of intestinal microbiota. • Synbiotic increases the abundance of butyrate-producing bacteria.

Hepatocellular carcinoma

Hepatocellular carcinoma (HCC) belongs to the most prevalent and deadliest cancers worldwide. It can be attributed to well-defined risk factors (mainly chronic viral hepatitis and alcoholic/nonalcoholic steatohepatitis) leading to liver cirrhosis, apremalignant condition for the development of preneoplastic hepatocellular lesions and finally liver cancer. By applying strict morphological criteria and apanel of immunohistological markers, early HCC can be differentiated from its precursor lesions and other highly differentiated hepatocellular lesions even in most biopsy specimens. Integrative characterization led to the association of histological features and molecular subgroups of human HCC. This potentially relevant clinical development was recognized by the recently updated WHO classification of liver cancer resulting in the introduction of several HCC subtypes. These are characterized by adistinct combination of histological and molecular features, biological behavior, and clinical characteristics, allowing for adistinction from other HCC without specified features. Whether this development sets the corner stone for precision oncology of human HCC patients must be monitored.

Protective Effects of Dietary Capsaicin on the Initiation Step of a Two-Stage Hepatocarcinogenesis Rat Model

Capsaicin (CPS), an ingredient of Capsicum plants, has anti-inflammatory, antioxidant and antitumoral properties. The mechanisms of CPS on hepatocarcinogenesis preclinical bioassays are not described. Thus, the protective effects CPS were evaluated in the early stages of chemically-induced hepatocarcinogenesis. Male Wistar rats received diet containing 0.01% or 0.02% CPS for 3 weeks. Afterwards, animals received a dose of hepatocarcinogen diethylnitrosamine (DEN, 100 mg/kg body weight). From weeks 4–12, groups had their diet replaced by a 0.05% phenobarbital supplemented one to promote DEN-induced preneoplastic lesions. Animals were euthanized 24 h after DEN administration (n = 5/group) or at week 12 (n = 9/group). The estimated CPS intake in rats resembled human consumption. At the end of week 3, dietary 0.02% CPS attenuated DEN-induced oxidative damage and, consequently, hepatocyte necrosis by reducing serum alanine aminotransferase levels, liver CD68-positive macrophages, lipid peroxidation, while increasing antioxidant glutathione system. Additionally, 0.02% CPS upregulated vanilloid Trpv1 receptor and anti-inflammatory epoxygenase Cyp2j4 genes in the liver. Ultimately, previous 0.02% CPS intake decreased the number of GST-P-positive preneoplastic lesions at week 12. Thus, CPS attenuated preneoplastic lesion development, primarily by diminishing DEN-induced oxidative liver injury. Findings indicate that CPS is a promising chemopreventive agent when administered after and during the early stages of hepatocarcinogenesis.

Early molecular events associated with liver and colon sub-acute responses to 1,2-dimethylhydrazine: Potential implications on preneoplastic and neoplastic lesion development

This study unveiled the early cellular and molecular events induced by 1,2-dimethylhydrazine (DMH) in the colon and liver and their implications on pre- and neoplastic lesion burden in a late timepoint. Male Wistar rats received four DMH injections (40 mg/kg body weight) for 2 weeks and were sacrificed 24 h (short-term study) or 22 (medium-term study) weeks after the last DMH administration. In the short-term study, DMH led to increased leukocyte (comet assay) and colon (H2AX) genotoxicity, enhanced proliferation (Ki-67) and apoptosis (caspase-3) indexes in both liver and colon. Furthermore, the expression of mRNA (Cat, Gsta1, Gsta2, Gpx1, Gstm1, Sod1, Sod2 and Sod3) and the activity of antioxidant agents were diminished in the colon and liver of DMH-induced rats, eliciting an environment of oxidative stress featuring elevated lipid hydroperoxide levels. Apoptosis effectors were upregulated in the liver (Bax, Casp3 and Fas), and developmental genes were downregulated in both colon and liver (Foxa1, Foxa2, Smad2 and Smad4). In the medium-term study, DMH led to a high number of preneoplastic colonic aberrant crypt foci and tumors (adenomas and invasive adenocarcinomas) but few preneoplastic hepatic glutathione S-transferase (GST-P)-positive foci. Our novel gene expression data highlights overlooked mechanisms in the liver (main metabolizing organ) and colon (main target organ) on toxicity and carcinogenesis induced by repeated doses of DMH, as both organs should be considered in further interventions on the initiation stage of colon carcinogenesis.