Christina Nikolaidou

Helicobacter pylori infection and colorectal carcinoma: pathologic aspects

To the Editor, Fleming et al. (1), by reviewing the pathologic aspects of colorectal neoplasms, summarized the pathogenesis and molecular classification of colorectal carcinoma (CRC) including mainly molecular pathways and environmental factors. However, they did not mention the potential pathologic aspects of environmental factors involved in colorectal oncogenesis, particularly in sporadic CRC. More than 95% of colorectal cancers are sporadic, also mentioned by the authors (1), without a significant hereditary risk. Geographic variation in the incidence of CRC is substantial with a higher incidence observed in the West. Environmental factors contribute considerably to this variation (2); the majority of the sporadic cancer is believed to be due to modification of mutation risk by other genetic and/or environmental factors. Dietary factors may influence the oncogenic process by modifying intestinal transit time, altering the flow and recycling of bile, or changing the intestinal bacterial flora composition. Numerous studies support a role for the gut microbiota in colorectal oncogenesis and the colonic microbiota drives the progression towards colorectal malignancy including generation of reactive metabolites and carcinogens, alterations in host carbohydrate expression and induction of chronic mucosal inflammation (3); long-term colonization of the colon by rogue commensal bacteria capable of inducing chronic DNA damage could contribute to sporadic CRC developement, thereby suggesting sporadic CRC as an infectious disease (4). In this regard, Helicobacter pylori (Hp), a curved spiral gram-negative bacterium found in the gastric mucosa of a large proportion of humans worldwide (>50%), has been evaluated as a possible etiologic agent for CRC and recent data indicate that there is a serological association between Hp infection (Hp-I) and the risk of CRC, especially for left-sided and early-stage cancers (5). Moreover, Hp seropositive subjects are associated with a modest increase in the risk for colorectal adenoma, and since Hp-I can increase the risk especially of advanced adenomas, the medical community should take into account that a preventive strategy is needed, and, furthermore, elucidating the pathophysiological role of Hp in the development of CRC is highly warranted (6). However, as mentioned by the authors (5,6), the serologic measurement of infection status is less than perfect, thereby representing a specific limitation of their studies. Indeed, the serological test does not discriminate between current and past infections and, apart from past infection that may even be more relevant for oncogenesis, such a distinction is essential because only current Hp-I induces humoral and cellular immune responses that produce or perpetuate chronic inflammatory processes in gastrointestinal tract with potential oncogenic sequelae; many neoplasms including colorectal adenomas and cancers arise at the sites of chronic inflammation and infection (7-10). Based on histology, the practical gold standard for Hp-I diagnosis, our own preliminary studies indicated Hp presence in malignant tissue in 34 of 41 (82.9%) patients with CRC (23 men, mean age 73.6±7.9 years) (11). Extending these preliminary data we currently included 50 patients (28 men, mean age 71.3±9.7 years) with CRC and 25 patients (13 men, mean age 72.8±10.1 years) with colonic polyps with the following results: Hp presence in malignant and polyp tissues of patients were observed in 84% and 64%, respectively, confirming our preliminary data (12). It is important to note that, apart from Cresyl fast violet staining mainly used to detect Hp, its presence was also documented by immunohistochemical method (using polyclonal rabbit anti-Hp antibody (dilution 1:50, DAKO, Athens, Greece) in adenoma and malignant colonic tissues. Specifically, in accordance with Hong et al. (6), Hp progressive increased presence was observed in our patients with adenomas associated with mild (50%) and moderate/high-grade (80%) dysplasia; the latter lesions are frequently described as advanced adenomas. However, contrary to the authors’ considerations (6), our series showed an increased Hp presence in left-sided (79%) than in the proximal colon (21%) adenomas; left-sided cancers were also observed in 70.7% of our patients, a finding also noticed by Zhang et al. (5), thereby suggesting that Hp-I might be associated with a rather relevant risk increase in the left CRC. The multistep model of gastric cancer postulates that there is initially an inflammation, caused mainly by Hp-I, which can lead to the development of chronic active gastritis. In a subset of these patients, this inflammatory process leads to the development of atrophic gastritis, followed by intestinal metaplasia, dysplasia, and, ultimately, early and advanced gastric cancer (13). It is considered that all stages prior to the development of high-grade dysplasia are potentially reversible, although this is still controversial (13). Because, Hp also induces inflammatory changes in colonic mucosa (14), it would be reasonable to further speculate, in view of our data, that chronic inflammatory process induced by Hp-I in colonic mucosa may lead to adenoma - mild-moderate/high grade dysplasia - CRC development sequence. These findings may emphasize the need for Hp eradication to prevent the development of both colon and gastric cancer (13). In addition, we found that presence of Hp in malignant colonic tissue was associated with Ki-67 oncogene increased expression in all tumor specimens and low expression in all adjacent tissue specimens (15). Moreover, p53 increased and low expression was observed in 72.5% and 100% of tumor and adjacent tissues specimens, respectively. Likewise, antiapoptotic Bcl-2 protein was observed in 60% and 9% of tissue specimens, respectively, whereas proapoptotic Bax protein was observed in 9% and 100% of tissue specimens, respectively (15). Therefore, Hp colonizing colonic neoplasm tissue seems to be associated with an increased cell proliferation and impaired apoptotic process in malignant tissue compared with normal adjacent colonic mucosa, thereby possibly contributing to colon normal mucosa-adenoma-cancer sequence (15). In this regard, Hp-induced gastrin as an oncogenic growth factor, shows antiapoptotic activity through the Bcl-2 upregulation and contributes to gastric and colon carcinogenesis through stimulation of mutagenic and tumorigenic cyclooxygenase-2 expression (16). Animal models suggested the mitogenic action of gastrin to be limited to the left colon, elevated gastrin levels are more pronounced in their associations with rectal than with colon cancer, and the relation between hypergastrinemia and colorectal adenomas confers an increased risk only for distal colon adenomas. These findings are consistent with and may explain our findings and Zhang et al. (5) findings of selective risk increase with respect to left-sided CRC and adenomas. Experimental data indicate that Hp-I leads to development of chronic inflammation, hyperplasia, metaplasia, dysplasia and recruitment and accumulation of bone marrow-derived cells (BMDCs) which may contribute to tumor formation in animal models with Hp-induced chronic gastric inflammatory process (9,13). Because Hp similarly induces the mentioned inflammatory changes in colonic mucosa (14), it would be reasonable to further speculate that chronic Hp-I in humans also induces repopulation of the colon with BMDCs that might facilitate colon adenoma and cancer development and progression (9,13). In this regard, our own preliminary studies indicated increased expression of CD44 [a marker of human hematopoietic stem and progenitor cells and cancer stem cells (CSCs)] in malignant colonic tissue in 75.6% patients with CRC (11). Extending these preliminary data, increased expression of CD44 was observed in 78% and 16% of patients with cancers and polyps, respectively (12). We also obtained comparable data with gastric cancer (9,13). Therefore, these findings suggest the possible BMDCs and/or CSCs involvement in Hp-associated gastric cancer development and colon adenoma and cancer growth and/or progression (9,13). However, larger-scale future studies are warranted to show that the BMDCs move into areas of the upper and lower gastrointestinal tract and/or CSCs might be induced in the context of Hp chronic injury or inflammation with potential long-term colon adenoma malignant consequences in Hp-positive subjects. Finally, it is important to know if the authors (1) considered relative pathologic aspects in their studies.

Upregulation of VEGF expression is associated with accumulation of HIF-1α in the skin of naïve scleroderma patients

Systemic sclerosis is a disease hallmarked by microangiopathy; the enlargement and leakage of skin capillaries in active stages develops into extensive avascular areas, clinically associated with severe tissue hypoxia and the formation of digital ulcers. Vascular endothelial growth factor (VEGF) is upregulated in all stages of the disease, with little effect on efficient neovascularization. The oxygen-regulated α-subunit of hypoxia-inducible transcription factor-1 (HIF-1α) represents a key mechanism involved in the transcriptional regulation of VEGF. The aim of this study is to investigate expression of the oxygen-regulated α-subunit of HIF-1 and VEGF in naïve scleroderma patients. For this purpose, skin biopsies (dorsal hand surface) from scleroderma patients were analyzed and compared with control skin biopsies. Immunoreactivity for VEGF was enhanced in scleroderma patients, in contrast to restricted positive immunostaining in suprabasal keratinocytes observed in normal skin. In a similar fashion, all skin biopsies from scleroderma patients were strongly HIF-1α reactive, compared with rare immunoreactivity observed in normal skin. The pattern was similar in all stages of scleroderma. These observations for the first time directly connect constitutive hypoxia with VEGF upregulation in scleroderma patients. The sequence of events needs to be precisely mapped, and the pro- and antiangiogenic switches which may interfere with efficient tissue neovascularization identified, in order to provide meaningful therapeutic strategies.

Impact of Helicobacter pylori Infection on colon oncogenesis.

To the Editor: Th e paradigm of Clostridium diffi cile -associated diarrhea (CDAD) is changing. Its incidence and severity are increasing. Th e emergence of hypervirulent strains of C. diffi cile is worrisome. Treatment failure rates are on the rise, and recurrence rates in treated patients are disappointing. Lately, CDAD has been described in populations previously thought to be at low risk. Nisin is a peptide antibiotic that exhibits bactericidal activity against Gram-positive organisms. It belongs to a class called the lantibiotics and is produced by the bacterium Lactococcus lactis subsp. Lactis ( 1 ). Nisin is safe and was granted GRAS status (Generally Recognized As Safe; notice no. GRN 000065) by the United States Food and Drug Administration. It is currently used as an additive to prevent food spoilage. Th e mode of action of nisin has been studied extensively. Th e cytoplasmic membrane is the primary target of nisin. It incorporates into the cytoplasmic membrane, leading to the formation of transient multistate pores that allow the effl ux of low-molecular mass molecules such as amino acids, K + , and internal adenosine triphosphate . As a result, both the membrane potential and pH gradients across the cytoplasmic membrane are dissipated, leading to cell lysis and death ( 2 ). More recently, nisin was found to interact with the lipid II molecule, which is an essential membrane-bound precursor for cell-wall biosynthesis ( 3 ). Nisin exhibits excellent in vitro activity against C. diffi cile . In fact, Bartoloni et al. ( 4 ) tested metronidazole, vancomycin, and nisin against 60 toxigenic strains of C. diffi cile collected from subjects with CDAD in hospital settings and found nisin to be eight times more eff ective than the current standard treatments ( 4 ). Preliminary animal studies have shown that nisin is poorly absorbed from the large intestine, which makes systemic toxicity less likely. It also attains high concentrations in the intestinal lumen and has no toxic eff ects on the intestinal epithelium ( 5 ). Nisin ’ s other advantage is its poor bactericidal activity against the most common gastrointestinal microbiota, Bacteroides and Prevotella ( 4 ). Nisin undergoes proteolytic degradation in the upper gastrointestinal tract, hence, it will require delivery directly to the colon of infected patients. Options include administering the medication as an enema or perhaps oral delivery via a coated capsule that will release the intact drug at the target site. For the reasons mentioned, nisin appears to be an excellent candidate agent for the treatment of CDAD and it merits further investigation in phase I clinical trials.

Umbilical Metastasis as Primary Manifestation of Cancer: A Small Series and Review of the Literature

Umbilical metastasis is a rare manifestation of intra-abdominal cancer. It appears either as the first sign of a primary malignancy or as metastatic site of an already diagnosed cancer, representing an ominous prognostic finding. We report three cases of umbilical metastasis as the first sign of an underlying malignancy. Hypotheses about pathophysiology of umbilical metastasis are based on the embryological origin of the umbilicus and its residual communication with systematic, portal and lymphatic circulation.

Potential oncogenic properties of mobilized stem cells in a subpopulation of inflammatory bowel disease patients infected with Helicobacter pylori.

To the Editor: Marlicz et al concluded that Crohn’s disease (CD) triggers the mobilization of various types of stem cells, such as hematopoietic stem progenitor cells, into peripheral blood in patients suffering from this disease, while the significance and precise role of these mobilized cells in repair of damaged intestine requires further study. However, the authors did not discuss the possibility of potential oncogenic properties of the mobilized stem cells, at least in the subgroup of patients possibly infected with Helicobacter pylori (H. pylori). In this regard, although relative data indicate an absence or inverse association between H. pylori and inflammatory bowel disease (IBD), the prevalence of H. pylori infection in the IBD patients appears to be 38.2%– 47% in Europe. Moreover, enterohepatic and gastric Helicobacter species have been documented in fecal specimens from children with CD using polymerase chain reaction (PCR), and H. pylori, for example, was recently found in the intestinal mucosa of a patient affected by CD. Experimental data indicate that H. pylori infection leads to development of chronic inflammation, hyperplasia, metaplasia, dysplasia, and recruitment and accumulation of bone marrow-derived cells (BMDCs) in the mouse gastric epithelial mucosa. Nearly 25% of dysplastic lesions include cells originating from BMDCs, thereby indicating that BMDCs can participate in preneoplastic lesions preceding gastric carcinoma development; there is a role for engraftment of circulating BMDCs, which may contribute to tumor formation in animal models with H. pylori-induced chronic gastric inflammatory processes, thus further suggesting the possibility of the potential contribution of BMDCs in human gastrointestinal carcinoma. In this regard, we recently conducted a pilot study using tissue sections of biopsies of human gastric cancer in which H. pylori was detected by Cresyl violet staining. Moreover, stem cells and neovessels were detected by immunohistochemical method using a monoclonal antibody, anti-CD34; CD34, also mentioned by the authors, is a surface glycoprotein expressed on hematopoietic stem cells and is used as an important marker of these cells and neovessels. In addition, cyclin D1, involved in the regulation of cell proliferation, was also detected by immunohistochemical method. Other relative data indicate that H. pyloriinduced cytotoxin VacA exhibits chemotactic activities to the BMDCs and induces BMDCs to produce proinflammatory cytokines, leading to chronic inflammation with potential oncogenic consequences. Therefore, it would be reasonable to speculate that chronic H. pylori infection in both mice and humans induces repopulation of the stomach with BMDCs that may facilitate gastric cancer progression. These findings present a new way of thinking about the pathogenesis of upper gastrointestinal malignancy. The observation that BMDCs are the origin of H. pylori-induced gastric cancer can also be combined with supporting observations of BMDCs in other tumors such as Barrett’s esophageal adenocarcinoma, Kaposi sarcoma, cancer-associated fibroblasts, or benign and malignant tumors of the skin. Other relative data, using the stem cell marker CD44 (the integral membrane molecule CD44 is a marker of human hematopoietic stem and progenitor cells), indicate that the CD44þ gastric cancer stem cells show the stem cell properties of selfrenewal, the ability to form differentiated progeny, and, moreover, increased resistance for chemotherapy or radiation-induced cell death; H. pylori either directly or through a local inflammatory response is responsible for increased expression of CD44 and its variant CD44 v9, thereby suggesting a possible H. pylori induction of CD44þ BMDCs/gastric cancer stem cells involved in gastric cancer development and progression. Because H. pylori also induces inflammatory changes in colonic mucosa, it would be reasonable to further speculate that chronic H. pylori infection in humans induces repopulation of the colon with BMDCs that might facilitate colon cancer development and progression. In this respect, our own preliminary studies indicated the presence of H. pylori in malignant colonic tissue in 34 of 41 (82.9%) patients with colorectal cancer (23 men, mean age 73.6 6 7.9 years). Moreover, increased expression of CD44 in malignant tissue but not in the adjacent normal colonic mucosa was noticed in 31 of 41 (75.6%) patients with colorectal cancer. Extending these preliminary data we currently included 50 patients (28 men, mean age 71.3 6 9.7 years) with colorectal cancer and 25 patients (13 men, mean age 72.8 6 10.1 years) with colonic polyps with the following results: H. pylori presence and increased expression of CD44 in malignant tissue of patients were observed in 84% and 78%, respectively, confirming our preliminary data. Comparable data in adenomatous tissue of patients with colonic polyps were also observed in 64% and 16% of patients, respectively Copyright VC 2012 Crohn’s & Colitis Foundation of America, Inc. DOI 10.1002/ibd.22911 Published online inWiley Online Library (wileyonlinelibrary.com).

Primary Gallbladder Small Lymphocytic Lymphoma as a Rare Postcholecystectomy Finding

Introduction. Primary lymphoma of the gallbladder is an extremely rare entity with approximately 50 cases reported so far. In many of these cases the presenting symptoms were mimicking symptomatic gallstone disease and the diagnosis was made postoperatively, especially when the preoperative imaging results were far from suspicious for malignant disease. Patients and Methods. We report a case of primary lymphoma of the gallbladder in an 85-year-old man with gallstone disease, who was admitted for elective cholecystectomy 2 months after an episode of acute cholecystitis and pancreatitis. Histological evaluation of the specimen revealed a small lymphocytic lymphoma of the gallbladder. This type of primary gallbladder lymphoma has not been previously reported. Discussion. The most common primary lymphomas of the gallbladder are MALT lymphomas and diffuse large B-cell lymphomas, although a variety of other histological types have been reported. The association of these lesions with chronic inflammation is the most convincing theory for their pathogenesis. For lesions confined to the gallbladder, cholecystectomy is considered to be sufficient, while supplementary chemotherapy significantly improves prognosis in more advanced disease.

The Immunohistochemical Expression MTA 1 Protein and its Prognostic Value in Pancreatic Cancer

ABSTRACT Purpose/aim: To examine with immunohistochemical assay MTA1 protein expression levels in pancreatic cancer tissues defining its prognostic value. Material and Methods: The specimens derived from 51 patients who underwent surgery. The levels of MTA1 protein were compared with the age of the patients, their survival, and prognosis. Also, we studied clinical and histopathological factors such as the degree of tumor differentiation and its stage in correlation with MTA1 protein levels. In parallel, there was correlation between the expression of the ΜΤΑ1 protein and the aforementioned factors regarding survival rate. Furthermore, we independently correlated the patients survival in relation to whether they had undergone adjuvant chemotherapy or not. Results: It has been found to be low, moderate, or high expression of MTA1 levels in 48 out of 51 cancer tissues. Specifically, 49.0% of patients had low expression, 33.3% moderate, and 11.8% high expression of MTA1. Regarding the expression of MTA1 protein in correlation with various clinical and histopathological factors, a statistically significant correlation was observed with the degree of differentiation (p = 0.0068) and with the stage of the disease (p = 0.0173), but not with survival (p = 0.0740) or the age of them (p = 0.1547). Finally, it was found that overexpression of the MTA1protein is a prognostic factor for shorter survival in patients with pancreatic cancer (average 4.67 ± 0.95 months). Conclusions: MTA 1 protein may constitute an important prognostic marker in pancreatic cancer and could improve prognosis and treatment.

Helicobacter pylori might contribute to cancer and/or bone marrow-derived stem cell-related gastrointestinal oncogenesis

Helicobacter pylori might contribute to cancer and/or bone marrow-derived stem cell-related gastrointestinal oncogenesis

Helicobacter pylori and Colorectal Cancer Risk—Letter

Epplein and colleagues ([1][1]) reported that the overall Helicobacter pylori ( H. pylori ) seropositivity was not associated with colorectal cancer risk, and seropositivity to specific H. pylori proteins, particularly the toxin VacA antibodies, may be associated with a higher risk of colorectal

Active Helicobacter pylori infection is associated with colorectal mucosa – adenomatous polyp – early and advanced adenocarcinoma sequence

To the Editor, Shmuely et al. [1] concluded that Helicobacter pylori infection (Hp-I) serology is associated with advanced colorectal neoplasia (ACRN) development. They postulated that (a) opposing histology, serology may remain positive even after curing the infection, and the latter is an advantage, as the past infectionmay be even more important for oncogenesis; (b) the specific neoplasia colorectal location was not associated with Hp-I presence, though their data were not shown; and (c) a few possible physiopathological mechanisms for Hp-I and ACRN association include bacterial direct oncogenic effect or hypergastrinemia indirect trophic effect on colorectal mucosa. However, the serological test does not discriminate between current and past infections and, apart from past infection that might even be more relevant for oncogenesis, such a distinction is crucial because only current Hp-I induces humoral and cellular immune responses that induce or perpetuate chronic inflammatory processes in gastrointestinal tract with potential oncogenicsequelae;manymalignancies, includingcolorectal carcinoma (CRC), arise at the sites of chronic inflammation and infection [2,3]. Likewise, two recent large-scale relative epidemiologic studies also suggest that serologic measurement of infection status is less than perfect, thereby representing a limitation of their estimations [4,5]; one study [5] was also mentioned by the authors [1]. Basedonhistology, thegoldstandardforcurrentHp-I diagnosis, ourdata in 50CRCpatients, 25patientswith colorectal adenomas (CRAs) and 10 controls, showed significantly higher presence ofHp-I in theCRA (68%) andCRC (84%) groups comparedwith controls (30%) [6,7]; Hp presence was documented by immunohistochemical stain in colonic tissues.Our series also showed a tendency of increasedHppresence in left-sided (79%) compared with the proximal colon (21%) adenomas; left-sidedcancers(LSCs)wereobservedin64.3%ofour patients, a finding also noticed by others [4], thereby suggesting a possibleHp-I-related risk for LSC in some subpopulations. PresenceofHp-Iwith immunohistochemical expression of CD44 [cancer stem cells (CSCs) and/or bone marrow-derived stem cells (BMDSCs) indicator] was found in a high proportion of CRA patients with moderate-severe dysplasia (88%) and CRC patients with moderate-severe degree of malignancy