Expression of Autophagic and Inflammatory Markers in Normal Mucosa of Individuals with Colorectal Adenomas: A Cross Sectional Study among Italian Outpatients Undergoing Colonoscopy

Colorectal cancer (CRC) ranks among the three most common cancers in terms of both cancer incidence and cancer-related deaths in Western industrialized countries. Lifetime risk of colorectal cancer may reach 6% of the population living in developed countries. In the current era of personalized medicine, CRC is no longer considered as a single entity. In more recent years many studies have described the distinct differences in epidemiology, pathogenesis, genetic and epigenetic alterations, molecular pathways and outcome depending on the anatomical site. The aim of our study is to assess in a multidimensional model the association between metabolic status and inflammatory and autophagic changes in the normal colorectal mucosa classified as right-sided, left-sided and rectum, and the presence of adenomas. One hundred and sixteen patients undergoing colonoscopy were recruited and underwent a complete serum lipid profile, immunofluorescence analysis of colonic biopsies for MAPLC3 and myeloperoxidase expression, matched with clinical and anthropometric characteristics. Presence of adenomas correlated with cholesterol (total and LDL) levels, IL-6 levels, and MAPLC3 tissue expression, especially in the right colon. In conclusion, serum IL-6 amount and autophagic markers could be good predictors of the presence of colorectal adenomas.

Complement opsonization of HIV affects primary infection of human colorectal mucosa and subsequent activation of T cells

HIV transmission via genital and colorectal mucosa are the most common routes of dissemination. Here, we explored the effects of free and complement-opsonized HIV on colorectal tissue. Initially, there was higher antiviral responses in the free HIV compared to complement-opsonized virus. The mucosal transcriptional response at 24 hr revealed the involvement of activated T cells, which was mirrored in cellular responses observed at 96 hr in isolated mucosal T cells. Further, HIV exposure led to skewing of T cell phenotypes predominantly to inflammatory CD4+ T cells, that is Th17 and Th1Th17 subsets. Of note, HIV exposure created an environment that altered the CD8+ T cell phenotype, for example expression of regulatory factors, especially when the virions were opsonized with complement factors. Our findings suggest that HIV-opsonization alters the activation and signaling pathways in the colorectal mucosa, which promotes viral establishment by creating an environment that stimulates mucosal T cell activation and inflammatory Th cells.

Patterns of polyp histology: predictors of peril in the mucosa

BACKGROUND

Precursor colonic polyps of varied subtypes correlate with the known neoplastic pathways. When patients present with synchronous pre-malignant polyps of multiple histologies, multiple genetic mechanisms are likely to be active, potentially resulting in a more unstable, tumourigenic mucosa.

METHODS

We hypothesized that patients with a combination of sessile serrated adenomas/polyps (SSA/Ps), hyperplastic (HP) polyps and adenomas would be at highest risk of developing dysplasia/cancer compared to SSA/Ps alone, due to the synergistic effect of multiple active carcinogenic pathways. A prospective colonoscopy database was examined for patients with a history of SSA/P. Patients were placed into four groups based on patterns of polyp histology as follows: (i) only SSA/Ps; (ii) SSA/P + HP; (iii) SSA/Ps + adenomas; and (iv) SSA/Ps + HP + adenomas. These groups were compared in terms of the numbers, size, location and histology of polyps and personal or family history of colorectal cancer.

RESULTS

A total of 374 patients were included. The average age was 70 years (range 21-88), and 43% were male. There was a trend towards the most aggressive neoplastic pattern in group 4, associated with a tendency to larger SSA/Ps, more villous architecture in the adenomas and more high-grade dysplasia in both types of polyps. It was also associated with multiplicity of both SSA/Ps and adenomas. No SSA/Ps existing in the absence of adenomas had cytological dysplasia.

CONCLUSION

The combination of SSA/Ps, HP and adenomas in the colorectal epithelium seems to be a marker for aggressive carcinogenesis and suggests that accurate and effective surveillance is important to manage this risk.

Protocol for the long-term culture of human primary keratinocytes from the normal colorectal mucosa

Procedures for in vitro culturing of human primary keratinocytes from normal colon mucosa specimens have not been fully feasible, thus far. The protocol described herein allows primary keratinocytes from small tissue fragments of colorectal mucosa biopsies to grow in vitro. The procedure develops in three steps: (a) the enzymatic digestion of the tissue biopsy; (b) the use of cloning rings to purify primary keratinocyte colonies, (c) a defined keratinocyte medium to grow these cells in long-term culture. Our cultural method enables normal primary keratinocytes to be obtained by simple and rapid techniques. In our culture condition, primary keratinocytes express specific epithelial markers. Colorectal mucosa keratinocyte colonies require approximately 2 weeks to grow. Compared with previous approaches, our protocol provides a valuable model of study for human primary keratinocytes from normal colorectal (NCR) mucosa both at the cellular and molecular levels. It is well known, that different mutations occurring during the multistep process of carcinogenesis in the NCR mucosa, are strictly associated to the onset/progression of the colorectal carcinoma. On this ground, normal keratinocytes grown with our protocol, may represent an innovative tool to investigate the mechanisms that lead to colorectal carcinoma and other diseases. Our innovative procedure may allow to perform comparative investigations between normal and pathological colorectal cells.

Gut-associated Lymphoid Tissue (GALT) Carcinoma in Ulcerative Colitis

BACKGROUND

In ulcerative colitis (UC), the majority of colorectal carcinomas (CRC) arise in the vast colorectal mucosal domain built with mucus-producing goblet cells and columnar cells. Conversely, CRC in UC rarely evolve in the tiny, spotty gut-associated lymphoid tissue (GALT) mucosal domain. Here we review the four reported cases of colonic carcinoma developing in GALT mucosa in UC, searching for possible precursor lesions connected with the evolution of these tumours.

MATERIALS AND METHODS

The clinical history, age, gender, endoscopic descriptions, and the pathology (localization, gross and histological descriptions of the luminal surface) of the four UC-GALT carcinomas reported in the literature were reviewed.

RESULTS

The luminal surface in three out of the four carcinomas revealed conventional (tubular/villous) adenomas or high-grade dysplasia. All four UC-GALT-carcinomas were detected at an early stage (T1N0).

CONCLUSION

GALT carcinomas do occur, albeit infrequently, in patients with UC. The finding that three out of the four GALT carcinomas on record were covered by conventional adenomas or by high-grade dysplasia strongly suggests that non-invasive conventional neoplasias might often precede GALT carcinomas in UC.

Transporters for Antiretroviral Drugs in Colorectal CD4+ T Cells and Circulating α4β7 Integrin CD4+ T Cells: Implications for HIV Microbicides

CD4+ T lymphocytes in the colorectal mucosa are key in HIV-1 transmission and dissemination. As such they are also the primary target for antiretroviral (ARV)-based rectal microbicides for pre-exposure prophylaxis. Drug transporters expressed in mucosal CD4+ T cells determine ARV distribution across the cell membrane and, most likely, efficacy of microbicides. We describe transporters for antiretroviral drugs in colorectal mucosal CD4+ T lymphocytes and compare gene expression with circulating α4β7+CD4+ T cells, which traffic to the intestine and have been shown to be preferentially infected by HIV-1. Purified total CD4+ T cells were obtained from colorectal tissue and blood samples by magnetic separation. CD4+ T cells expressing α4β7 integrin were isolated by fluorescence-activated cell sorting from peripheral blood mononuclear cells of healthy volunteers. Expressions of 15 efflux and uptake drug transporter genes were quantified using Taqman qPCR assays. Expression of efflux transporters MRP3, MRP5, and BCRP and uptake transporter CNT2 were significantly higher in colorectal CD4+ T cells compared to circulating CD4+ T cells (p = 0.01-0.03). Conversely, circulating α4β7+CD4+ T cells demonstrated significantly higher expression of OATPD compared to colorectal CD4+ T cells (p = 0.001). To the best of our knowledge this is the first report of drug transporter gene expression in colorectal CD4+ and peripheral α4β7+CD4+ T cells. The qualitative and quantitative differences in drug transporter gene expression profiles between α4β7+CD4+ T cells and total mucosal CD4+ T cells may have significant implications for the efficacy of rectally delivered ARV-microbicides. Most notably, we have identified efflux drug transporters that could be targeted by selective inhibitors or beneficial drug-drug interactions to enhance intracellular accumulation of antiretroviral drugs.

Significance of apoptosis in the process of tumorigenesis in colorectal mucosa and adenomas in FAP patients

The relation between proliferation and apoptosis was studied in colorectal mucosal biopsies (N = 41), tubular adenomas (TA) (N = 104) and tubulovillous adenomas (TVA) (N = 34) from 37 FAP patients. Proliferative activity was determined by cell cycle distribution analysis. In addition, transcriptional capacity was determined by chromatin in situ testing. For both, DNA flow cytometry was used. Cycling cells were identified by immunohistochemical staining with monoclonal antibody Ki67. The existence of subdiploid apoptotic cells was derived from DNA and/or DNA/protein patterns. In a follow-up group, the mucosa is characterised by a balance between proliferation (S % + G2M % = 19) and apoptotic cells (% = 17). The percentage of Ki67 positive cells (16%) corresponds to the percentages mentioned above. In TA, the amount of apoptotic cells remains unaltered, in TVA it decreases to 8%. At the same time, the percentage of Ki67 positive cells increases significantly in both TA and TVA (39%, 42%). With patients who underwent surgery due to clinical signs without histological evidence for malignancy, apoptotic cells in TA continue to decrease significantly (9%), without any changes in cycling cells. Only in the carcinoma-bearing bowel, cycling cells increase to 52%. Here, the percentage of apoptotic cells in TVA reaches the lowest level (5%). A connection between proliferation and apoptosis was observed in mucosa and TVA. The process of tumorigenesis is characterised by a stepwise increase in resistance to apoptosis followed by an increase in cycling cells.

Flat serrated adenomas and flat tubular adenomas of the colorectal mucosa: differences in the pattern of cell proliferation

In the present work we have investigated the cell proliferation pattern of flat serrated adenomas and flat tubular adenomas. For this purpose tissue sections from 23 consecutive flat serrated adenomas and 22 consecutive flat tubular adenomas of the colorectal mucosa were challenged with MIB1, a monoclonal antibody directed against a proliferation-related antigen. The results (including semi-quantitative studies) demonstrated that, whereas flat serrated adenomas had a high cell proliferation at the lower part of the crypts, flat tubular adenomas had a high cell proliferation in the upper part of the crypts. In serrated adenomas with invasive adenocarcinoma, high cell proliferation was demonstrated both at the lower portion of the crypts and in the subjacent submucosa. This suggests that the cells of the lower portion of the crypts in serrated adenomas are truly neoplastic, with the capacity to evolve into invasive growth. The difference in cell proliferation between the two types of flat lesions reported here is a new argument in favor of the classification of flat serrated adenomas as a novel and independent type of neoplastic change of the colorectal mucosa.

Red and blue distinctive mucin-histochemical types of Japanese colorectal mucosa

Mucin-histochemical characteristics of normal human colorectal mucosa were investigated utilizing Culling et al.'s staining method which distinguishes the mode of C8-O-acylation of sialomucins. Normal mucosae of cecum, ascending, transverse and descending colon and rectum were obtained from autopsy and biopsy material. Japanese colorectal mucosa stained either entirely red or entirely blue, in contrast to previous reports dealing with Caucasians where all the normal mucosa reportedly stained red. The ratio of red to blue colon cases varied to some extent with age, i.e. it was found to be 1:1 in children aged 0 to 4, 2:1 in the 5-20 age group, and 4:1 in people older than 21 years, suggesting a tendency of shift from blue to red during early life in Japan. Each individual Japanese adult colorectal mucosa may thus be classified into either red or blue type mucin-histochemically.

Postoperative active specific immunization in curatively resected colorectal cancer patients with a virus-modified autologous tumor cell vaccine

Active specific immunotherapy was performed in a phase I study in 20 colorectal cancer patients after surgical resection of the tumor. An autologous tumor cell vaccine surface modified by Newcastle disease virus (NDV) was used, which showed the following characteristics. After mechanical and enzymatic dissociation of the tumor tissue an average of 5 x 10(7) cells/g tissue was obtained. According to trypan blue dye exclusion assay the average viability was 72%. Following irradiation (200 Gy) the inactivation of proliferative activity of the cells could be demonstrated by the absence of incorporation of 3H-labelled thymidine. The cells were, however, still metabolically active as shown by the incorporation of [3H]-uridine and a mixture of 3H-labelled amino acids. Epithelium-specific antigens (detected by mAb HEA125) were expressed on more than 75% cells of the cell suspension indicating a high amount of (epithelium-derived) tumor cells. In order to increase the immunogenicity of the tumor cells the suspended cells were infected by the nonlytic, apathogenic Ulster strain of NDV. The successful modification of tumor cells with NDV could be shown by electron microscopy. Three weeks postoperatively cells were thawed, virus-modified, and inoculated intradermally in the upper thigh. Several cell and virus concentrations were tested in each patient. As control, tumor cells without NDV, NDV alone and normal colon mucosa were used. The number of tumor cells ranged from 2 x 10(6) up to 2 x 10(7) cells and NDV concentrations from 4 to 64 hemagglutination units (HU) were tested. Sixteen patients responded with a delayed-type hypersensitivity (DTH) skin reaction to the vaccine. The best DTH reaction, measured 24 h following vaccination, was obtained using a vaccine consisting of 1 x 10(7) tumor cells and 32 HU NDV (median induration of 8 mm). Response to NDV alone was seen in 2 patients only (median induration of 3 mm); 12 patients responded to tumor cells (1 x 10(7) alone (median induration of 4 mm). Of 10 patients tested with normal colorectal mucosa, 4 responded with a median induration of 3.5 mm. DTH responses to the vaccine of 1 x 10(7) tumor cells and 32 HU NDV increased throughout the repeated vaccinations to a median induration of 9.5 mm at the end of the therapy. No severe side-effects in the course of the immunotherapy, except for mild fever in 4/20 patients, were observed. The results of our phase I study show that this type of autologous colorectal tumor cell vaccine is ready for a large clinical trial to prove its efficacy.