Presence Of Preneoplastic Lesions Research Articles

3\u2019UTR polymorphism of Thymidylate Synthase gene increased the risk of persistence of pre-neoplastic cervical lesions

BackgroundCervical cancer is caused by high-risk Human Papillomavirus (hr-HPV) infection associated with cofactors that has been analyzed as predictors of the remission or persistence of cytological abnormalities remission or persistence. These cofactors can be either environmental, epigenetic, or genetic. Polymorphism in genes of enzymes that act on one-carbon metabolism alter their activity and also may be associated with cervical carcinogenesis because they affect DNA synthesis and repair, and gene expression. Therefore, this study aimed to analyze the risk of persistence of pre-neoplastic cervical lesions according to genetic polymorphisms involved in one-carbon metabolism.MethodsOur sample consisted of 106 women, divided into two groups – Remission (n = 60), i.e., with the presence of pre-neoplastic lesions at first meeting (T1) and normal cytology after 6 months of follow-up (T2), and Persistence (n = 46), i.e., with the presence of pre-neoplastic lesions at T1 and T2. We obtained cervical samples for cytological analysis (T1 and T2), HPV detection (T1), and evaluation of polymorphism C667T of Methylenetetrahydrofolate Reductase (MTHFR C677T), A2756G of Methionine Synthase (MS A2756G), A66G of Methionine Synthase Reductase (MTRR A66G), double or triple 28 bp tandem repeat in 5′-untranslated enhanced region of Thymidylate Synthase (TSER), and 6 bp deletion at nucleotide 1494 in TS 3′-untranslated region (TS3’UTR). To analyze all genetic polymorphisms simultaneously, we calculated the Genetic Risk Score (GRS).ResultsWe observed no differences between the Remission and Persistence groups regarding the GRS. Also, there were no differences in the genotypic and allelic distribution of MTHFR C677T and MS A2756G polymorphisms. However, the risk of persistence was higher among women with the heterozygote genotype - ins/del [OR (IC95%): 3.22 (1.19–8.69), p = 0.021], or the polymorphic genotype – del/del [OR (IC95%): 6.50 (1.71–24.70), p = 0.006] of TS3’UTR. Conclusions: The presence of the TS3’UTR polymorphism increased the risk of persistence of cervical abnormalities. This genetic variant could be a potential marker of cervical carcinogenesis and therefore assist the follow-up of women with persistent pre-neoplastic cervical lesions.

COX-2 gene expression and methylation profile in Sapajus apella as an experimental model for gastric adenocarcinoma.

Gastric cancer (GC) remains one of the main causes of cancer-related death worldwide. There are two distinct histological types of GC: diffuse and intestinal. The latter is characterized by the presence of pre-neoplastic lesions. One of the most frequently altered enzymes in intestinal GC is COX-2, an important lesion marker. This work aimed to study COX-2 methylation and expression in N-methyl-N-Nitrosurea (MNU)-induced intestinal GC in six Sapajus apella animals. The partial promoter sequence of S. apella COX-2 gene was obtained and used to identify transcription factors and cis-regulatory element binding sites. The COX-2 methylation pattern was assessed using Methylation-Specific PCR (MSP), and expression was analyzed by immunohistochemistry (IHQ). A total of 20 samples were obtained. A 675 bp fragment of the S. apella COX-2 promoter region was obtained, and it was 99.2% and 68.2% similar to H. sapiens and S. boliviensis, respectively. Similar to humans, several transcription factors and cis-regulatory element binding sites were identified in the S. apella sequence. MSP revealed that all samples were methylated. However, IHQ results demonstrated positive COX-2 expression in all pre-neoplastic and tumoral samples. The results suggest that the analyzed fragment is not crucial in COX-2 regulation of GC in S. apella.

Inhibition of diethylnitrosamine-initiated alcohol-promoted hepatic inflammation and precancerous lesions by flavonoid luteolin is associated with increased sirtuin 1 activity in mice.

Chronic and excessive alcohol consumption is an established risk for hepatic inflammation and carcinogenesis. Luteolin is one of the most common flavonoids present in plants and has potential beneficial effects against cancer. In this study, we examined the effect and potential mechanisms of luteolin supplementation in a carcinogen initiated alcohol-promoted pre-neoplastic liver lesion mouse model. C57BL/6 mice were injected with diethylnitrosamine (DEN) [i.p. 25 mg/kg of body weight (BW)] at 14 days of age. At 8 weeks of age mice were group pair-fed with Lieber-DeCarli liquid control diet or alcoholic diet [ethanol (EtOH) diet, 27% total energy from ethanol] and supplemented with a dose of 30 mg luteolin/kg BW per day for 21 days. DEN-injected mice fed EtOH diet displayed a significant induction of pre-neoplastic lesions, a marker associated with presence of steatosis and inflammation. Dietary luteolin significantly reduced the severity and incidence of hepatic inflammatory foci and steatosis in DEN-injected mice fed EtOH diet, as well the presence of preneoplastic lesions. There was no difference on hepatic protein levels of sirtuin 1 (SIRT1) among all groups; however, luteolin supplementation significantly reversed alcohol-reduced SIRT1 activity assessed by the ratio of acetylated and total forkhead box protein O1 (FoXO1) and SIRT1 target proliferator-activated receptor gamma, coactivator 1 alpha (PGC1α). Dietary intake of luteolin prevents alcohol promoted pre-neoplastic lesions, potentially mediated by SIRT1 signaling pathway.

Flavonoid luteolin supplementation inhibits diethylnitrosamine‐initiated alcohol‐promoted hepatic inflammation and precancerous lesions in mice (829.7)

Chronic and excessive alcohol consumption is an established risk for hepatic inflammation and carcinogenesis. Luteolin is one of the most common flavonoids present in plants and has potential beneficial effects against chronic diseases. In this study, we examined the effect and potential mechanisms of luteolin supplementation in a carcinogen (diethylnitrosamine [DEN])‐initiated alcohol‐promoted pre‐neoplastic liver lesion mouse model. C57BL/6 mice were injected with DEN (i.p. 25 mg/kg of body weigth [BW]) at 14 days of age. At 8 weeks of age mice were group pair‐fed with Lieber‐DeCarli liquid control diet or alcoholic diet (EtOH diet, 27% total energy from ethanol) and supplemented with a dose of 30 mg luteolin/kg BW/day for a treatment period of 21 days. Results show a significant induction in the incidence and multiplicity of basophilic and eosinophilic foci, markers of pre‐neoplastic liver lesions, in DEN‐injected mice fed EtOH diet. The presence of pre‐neoplastic lesions was significantly correlated with the induction of steatosis and inflammatory foci in these mice. Supplementation with luteolin inhibited the presence of pre‐neoplastic liver lesions in DEN‐injected mice fed EtOH diet. Dietary luteolin significantly reduced the severity of hepatic inflammatory foci with an associated non‐significant reduction in expression of hepatic inflammatory cytokines TNF‐α, IL‐6 and IL‐1β. There was no difference on hepatic protein levels of sirtuin 1 (SIRT1), however, luteolin supplementation significantly reversed alcohol‐reduced SIRT1 activity assessed by the ratio of acetylated and total FoXO1. The study demonstrated that luteolin prevents EtOH diet‐promoted hepatic inflammation and pre‐neoplastic lesion, potentially mediated by SIRT1‐FoxO1 signaling pathway. Grant Funding Source: USDA/ARS grant 1950‐51000‐074S

P2-01-02: Pharmacological Inhibition of RANKL Attenuates Mammary Tumor Development and Lung Metastases in the MMTV-neu Transgenic Spontaneous Tumor Model.

Abstract Background: RANK and its ligand (RANKL), key factors for bone remodeling and metastasis, are crucial for the development of mouse mammary glands during pregnancy. In a mouse model of mammary carcinogenesis induced by the hormone medroxyprogesterone (MPA) and a carcinogen (DMBA), treatment with a RANKL inhibitor RANK-Fc reduces hormone-induced mammary epithelial proliferation, incidence of preneoplasias, and mammary adenocarcinomas. This study assessed the expression of mouse RANK and RANKL in FVB wild-type (WT) and MMTV-neu mice and whether RANKL inhibition could inhibit mammary tumor formation and lung metastases in this model. Materials and Methods: MMTV-neu mice were treated with the RANKL inhibitor RANK-Fc (10 mg/kg, 3x/week) or vehicle (muFc) beginning at 20 weeks. Mammary tumor formation was determined by palpation and confirmed by histologic examination. The presence of preneoplastic lesions and histotype of tumors was determined on H&E-stained tissues. Entire lungs from tumor-bearing MMTV-neu mice were step-sectioned at 75 μm and assessed histologically for the presence of metastases. Epithelial proliferation was measured by BrdU labeling of the mammary epithelium. The expression of RANK, RANKL, cyclin D1, progesterone receptor (PR), F4/80, FOXP3, and CD3 was determined by immunohistochemistry (IHC). Results: RANK-Fc treatment of MMTV-neu mice resulted in a significant reduction in total number of mammary tumors and lung metastases quantified at necropsy but did not impact median time to spontaneous mammary tumor onset. RANKL inhibition resulted in reduced pre-neoplasias and corresponding reductions in proliferation and cyclin D1 within normal mammary epithelia but not in adenocarcinomas. Treatment of MMTV-neu mice with RANK-Fc also reduced the incidence and number of lung metastases per mouse. RANK protein was detected in normal mammary epithelium, preneoplastic mammary intraepithelial neoplasia (MIN), the epithelial component of adenocarcinomas and lung metastases, and monocytic element adjacent to primary MMTV-neu tumors. RANKL protein was detected in normal mammary epithelium but not in the epithelia, stromal component or infiltrating cells of adenocarcinomas or lung metastases. Progesterone receptor expression was observed in normal mammary epithelium of MMTV-neu and FVB WT mice but decreased over time in MMTV-neu mice and was not detected in preneoplasias, adenocarcinomas, or lung metastases. CD3 was detected in mammary tumors and lung metastases but neither RANKL nor FOXP3 were present. Staining of lymph nodes was used as a positive control for RANKL and FOXP3. Expression of FOXP3 and RANKL were not measurably colocalized in dual staining of lymph nodes. Discussion: RANKL is expressed in normal mammary epithelia of MMTV-neu mice but is not detected in any stage of atypia, including MIN, mammary adenocarcinoma, or lung metastases. Selective pharmacological inhibition of RANKL by RANK-Fc treatment attenuated mammary tumor development and lung metastases in the MMTV-neu transgenic spontaneous tumor model. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-01-02.

Induction of Apoptosis as a Potential Chemopreventive Effect of Dual Cycloxygenase Inhibitor, Diclofenac, in Early Colon Carcinogenesis

We evaluated the role of diclofenac, a dual cycloxygenase inhibitor, in chemoprevention of 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in rat model. In a six-week long treatment with DMH (initiation stage), colonic mucosa showed a rich presence of preneoplastic lesions, such as multiple plaque lesions (MPL), aberrant crypt foci (ACF), and histologically well-characterized dysplasia. Control animals were free from these features while simultaneous treatment of DMH and diclofenac resulted in a significant reduction of these. The Diclofenac-only group did not show any prominent carcinogenic feature. The colonic tissue showed increased COX-2 expression in the DMH group, immunohistochemically and by western blotting. Apoptosis was quantified in isolated colonocytes by fluorescent staining and by TUNEL assay in tissue sections. The number of apoptotic cells was few in the DMH group, while it was featured prominently in all the other groups. The dose of the diclofenac used in the present study was established at an anti-inflammatory dose by the carrageenan-induced rodent paw oedema test. Because ACF can be accepted as reliable prognostic biomarkers in colon carcinogenesis, its inhibition and also the induction of the apoptosis process may favorably indicate the preclinical promise for chemoprevention of colon cancer as demonstrated in the initiation phase of carcinogenesis.