Peritumoral Mucosa Research Articles

Peritumor Mucosa in Advanced Laryngeal Carcinoma Exhibits an Aberrant Proangiogenic Signature Distinctive from the Expression Pattern in Adjacent Tumor Tissue.

The field cancerization theory is an important paradigm in head and neck carcinoma as its oncological repercussions affect treatment outcomes in diverse ways. The aim of this study is to assess the possible interconnection between peritumor mucosa and the process of tumor neoangiogenesis. Sixty patients with advanced laryngeal carcinoma were enrolled in this study. The majority of patients express a canonical HIF-upregulated proangiogenic signature with almost complete predominancy of HIF-1α overexpression and normal expression levels of the HIF-2α isoform. Remarkably, more than 60% of the whole cohort also exhibited an HIF-upregulated proangiogenic signature in the peritumoral benign mucosa. Additionally, the latter subgroup had a distinctly shifted phenotype towards HIF-2α upregulation compared to the one in tumor tissue, i.e., a tendency towards an HIF switch is observed in contrast to the dominated by HIF-1α tumor phenotype. ETS-1 displays stable and identical significant overexpression in both the proangiogenic phenotypes present in tumor and peritumoral mucosa. In the current study, we report for the first time the existence of an abnormal proangiogenic expression profile present in the peritumoral mucosa in advanced laryngeal carcinoma when compared to paired distant laryngeal mucosa. Moreover, we describe a specific phenotype of this proangiogenic signature that is significantly different from the one present in tumor tissue as we delineate both phenotypes, quantitively and qualitatively. This finding is cancer heterogeneity, per se, which extends beyond the "classical" borders of the malignancy, and it is proof of a strong interconnection between field cancerization and one of the classical hallmarks of cancer-the process of tumor neoangiogenesis.

Automated Assessment of the Area of Infiltration by CD8+ Cells in Gastric Carcinoma and Areas of Normal Mucosa as a Significant Prognostic Factor.

In 139 patients with verified gastric cancer, the infiltration of the postoperative material with CD8+ cells was analyzed. Automated morphometric analysis of immunostained slides was performed separately in different specimen sites (tumor center, invasive edge, and peritumoral mucosa). The mean area of infiltrating CD8+ cells in the tumor center and in the invasive edge was not predictive, while in the peritumoral mucosa it provided a new negative predictive factor (hazard ratio 2.10; confidence interval 0.87-4.92, Cox regression) reliably associated with the TNM stage (hazard ratio 1.91; confidence interval 0.91-4.61, Cox regression).

Tumor immune microenvironment in therapy-naive esophageal adenocarcinoma could predict the nodal status.

Currently, preoperative staging of esophageal adenocarcinoma (EAC) has modest reliability and accuracy for pT and pN stages prediction, which heavily affects overall survival. The interplay among immune checkpoints, oncogenes, and intratumoral and peritumoral immune infiltrating cells could be used to predict loco-regional metastatic disease in early EAC. We prospectively evaluated immune markers expression and oncogenes status as well as intratumoral and peritumoral immune infiltrating cells populations in esophageal mucosa samples obtained from neoadjuvant therapy-naïve patients who had esophagectomy for EAC. Vascular invasion and high infiltration of lamina propria mononuclear cells resulted associated with nodal metastasis. Low infiltration of activated CD8+ CD28+ T cells was observed in both intratumoral and peritumoral mucosa of patients with nodal metastasis. Low levels of CD69, MYD88, and TLR4 transcripts were detected in the intratumoral specimen of patients with lymph node involvement. Receiver operating characteristic curve analysis showed good accuracy for detecting nodal metastasis for all the markers tested. Significant lower infiltration of CD8 T cells and M1 macrophages and a lower expression of CD8A, CD8B, and TBX21 were found also in Esophageal Adenocarcinoma TCGA panCancer Atlas in the normal tissue of patients with nodal metastasis. Our data suggest that immune surveillance failure is the main driver of nodal metastasis onset. Moreover, nodal metastasis containment also involves the immune microenvironment of the peritumoral healthy tissue.

Clinical and pathological profile of gastric neuroendocrine tumors.

Gastric neuroendocrine tumors (G-NETs) are classified into well-differentiated NETs with three grades and poorly differentiated neuroendocrine carcinomas based on morphology and the Ki-67 index. Besides, G-NETs are broadly classified into four types based on clinical and pathophysiological features. To study clinical and pathological features of different types and grades of G-NET. All G-NETs, diagnosed from January 2011 to December 2020, were included. Clinical presentation, peritumoral findings, lymph node status, and liver involvement were obtained and correlated with different grades and types of G-NETs. NET was diagnosed in 88 cases. Tumors were graded as I, II, III, and carcinoma in 58, 14, 12, and 4 cases, respectively. Type I NET (49.2%) in the background of chronic atrophic gastritis was the most common type followed by type III (33.3%). Type I tumors were predominantly graded I (91.1%) and limited to the mucosa and submucosa. MEN-1-associated G-NET (type II) was seen in eight cases. All except one type II tumor was associated with ZES syndrome. Remarkably, peritumoral mucosa showed atrophy and intestinal metaplasia in 52.1% and 24.6% cases, respectively. Two cases were associated with adenocarcinoma. Lymph node metastasis was seen in all carcinoma and grade III cases. All carcinoma cases and 58.3% of grade III tumors showed liver metastasis. Biological behavior of G-NET varies with different types and grades of tumor. Typing and grading of G-NET should be done whenever possible to predict the aggressiveness of the tumor.

Stepwise correlation of TP53 mutations from pancreaticobiliary maljunction to gallbladder carcinoma: a retrospective study

BackgroundThe genetic changes underlying carcinogenesis in patients with risk factors of gallbladder carcinoma (GBC) remains controversial, especially in patients with pancreaticobiliary maljunction (PBM). This study aimed to clarify the association between risk factors of GBC and genetic changes using next-generation sequencing (NGS).MethodsWe retrospectively analyzed resected tissues of 64 patients who were diagnosed with GBC (n = 26), PBM [with GBC (n = 8), without GBC (n = 20)], and chronic cholecystitis, used as a control group (n = 10). DNA was extracted from tumors and their surrounding tissues, which were precisely separated by laser-capture microdissection. Gene alterations of 50 cancer-related genes were detected by NGS and compared with clinical information, including PBM status.ResultsThe most frequent gene alterations in GBC tissues occurred in TP53 (50%), followed by EGFR (20.6%), RB1 (17.6%), and ERBB2 (17.6%). Gene alterations that were targetable by molecular targeted drugs were detected in 20 cases (58.8%). Statistical analysis of gene alterations and risk factors revealed that TP53 alteration rate was higher in GBC patients with PBM than those without PBM (p = 0.038), and the TP53 mutation rates in the epithelium of control patients, epithelium of PBM patients without GBC, peritumoral mucosa of GBC patients with PBM, and tumor tissue of GBC patients with PBM were 10, 10, 38, and 75%, respectively (p < 0.01).ConclusionsTP53 alteration more than KRAS mutation was revealed to underlie carcinogenesis in patients with PBM.

Neuroendocrine neoplasms of the esophagus and stomach

SummaryEsophageal neuroendocrine neoplasms (E-NENs) are much rarer than other gastro-entero-pancreatic neuroendocrine neoplasms, the majority showing aggressive behavior with early dissemination and poor prognosis. Among E-NENs, exceptionally rare well differentiated neuroendocrine tumors (E-NET) and more frequent esophageal poorly differentiated neuroendocrine carcinomas (E-NEC) and mixed neuroendocrine-non neuroendocrine neoplasms (MiNEN) can be recognized. E-NECs usually exhibit a small cell morphology or mixed small and large cells. Esophageal MiNEN are composed of NEC component admixed with adenocarcinoma or squamous cell carcinoma. Gastric (G) NENs encompass a wide spectrum of entities ranging from indolent G-NETs to highly aggressive G-NECs and MiNENs. Among G-NETs, ECL-cell NETs are the most common and, although composed of histamine-producing cells, are a heterogeneous group of neoplastic proliferations showing different clinical and prognostic features depending on the patient’s clinico-pathological background including the morphology of the peri-tumoral mucosa, gastrin serum levels, presence or absence of antral G-cell hyperplasia, and presence or absence of MEN1 syndrome. In general, NET associated with hypergastrinemia show a better outcome than NET not associated with hypergastrinemia. G-NECs and MiNENs are aggressive neoplasms more frequently observed in males and associated with a dismal prognosis.

Study of Muc2 and Muc4 Mucins in Cancer of the Higher Aerodiversity

Objectve: To know the role played by the MUC2 and MUC4 mucins genes in cancers of the upper aerodigestve tract. Material and methods: It was a cross-sectonal retrospectve study of 10 years (July 2004 - July 2013) carried out in the otolaryngology departments of the University Hospital Center of Brazzaville and general hospital Adolph Sice (in Pointe-noire, Congo). All patents with upper aerodigestve tract cancers with histological evidence were included. For the study of mucins “MUC2 et MUC4” the molecular biology technique used was immunohistochemistry on pieces of laryngeal biopsies embedded in parafn. Results: A total of 85 cases of upper aerodigestve tract cancers were collected with a sample comprising the tumor and peri tumoral mucosa. The incidence was 8.5 cases of upper aero-digestve tract cancer per year and a rato of 1.8 in favor of men. The main risk factor was smoking (94.2%) and all patents with squamous cell carcinoma found on the tumor lining. On immunohistochemistry, the mucins MUC2 and MUC4 were present in the normal mucosa of the upper aero-digestve tract and gradually lost their expression from the metaplastc mucosa to the tumor mucosa (P=0.03). These mucins “MUC2 and MUC4” were absent on tumor mucosa in both smoking and non-smoking patents with a statstcally signifcant di?erence (P=0.01). Conclusion: The loss of expression of the MUC2 and MUC4 genes within the tumor mucosa is a key mechanism in the carcinogenesis of the upper aerodigestve tract.

Visualization of mucosal field in HPV positive and negative oropharyngeal squamous cell carcinomas: combined genomic and radiology based 3D model

The aim of this study was to visualize the tumor propagation and surrounding mucosal field in radiography-based 3D model for advanced stage HNSCC and combine it with HPV genotyping and miRNA expression characterization of the visualized area. 25 patients with T1-3 clinical stage HNSCC were enrolled in mapping biopsy sampling. Biopsy samples were evaluated for HPV positivity and miR-21-5p, miR-143, miR-155, miR-221-5p expression in Digital Droplet PCR system. Significant miRNA expression differences of HPV positive tumor tissue biopsies were found for miR-21-5p, miR-143 and miR-221-5p compared to the HPV negative tumor biopsy series. Peritumoral mucosa showed patchy pattern alterations of miR-21-5p and miR-155 in HPV positive cases, while gradual change of miR-21-5p and miR-221-5p was seen in HPV negative tumors. In our study we found differences of the miRNA expression patterns among the HPV positive and negative tumorous tissues as well as the surrounding mucosal fields. The CT based 3D models of the cancer field and surrounding mucosal surface can be utilized to improve proper preoperative planning. Complex evaluation of HNSCC tissue organization field can elucidate the clinical and molecular differentiation of HPV positive and negative cases, and enhance effective organ saving therapeutic strategies.

Comparative miRNA Expression Profile Analysis of Squamous Cell Carcinoma and Peritumoral Mucosa from the Meso- and Hypopharynx

The role of microRNAs (miRNA) in carcinogenesis is related to their genome-regulatory function. The aim of the present study was to identify and compare miRNA expression signatures of meso- and hypopharynx squamous cell cancers in consideration of the cancer field hypothesis. Thirteen snap-frozen biopsy series of tumors and peritumoral tissues from the meso- and hypopharynx were analyzed regarding their miRNA expression with quantitative real-time polymerase chain reaction (qRT-PCR). Significant miRNA expression changes of miR-21, -27a, -34a, -143 and -146a were found in peritumoral tissues that were dependent from the tumor location and the distance from the primary tumor site. miRNA expression analysis was found to be appropriate for molecular segregation of tumor location and peritumoral tissue segments, and appears to be a promising marker for cancer field characterization.

Characteristics of B-lymphocytic infiltration in the peritumoral mucosa of the stomach in its cancer: Clinical and morphological aspects

Characteristics of B-lymphocytic infiltration in the peritumoral mucosa of the stomach in its cancer: Clinical and morphological aspects

The co-localization of carcinomas and adenomas favors a regional field defect in the colon: an observational study.

Finding common genetic alterations in colorectal cancers (CRCs) and peri-tumoral mucosa first led to the notion of colonic field defects. The hypothesis of a genetically determined mosaicism would explain these defects and would make the co-localization of tumors likely. Our purpose was to indirectly test this hypothesis by searching for a possible correlation between the location of colorectal cancers and adenomas This is a retrospective observational study. Patients operated for colorectal cancers at an oncological hospital, who had a full colonoscopy performed in the two peri-operative years, were surveyed. Sex, age, familial risk of cancer, tumor and adenoma locations, and the presence of adenomas larger than 1 cm, with villous component or high-grade dysplasia were recorded. T test, chi-square, exact, logistic regression (SPSS18®). This study included 224 patients (57 % male, mean age 67.6 years), 45 % of which had synchronous adenomas. There was a significant correlation between cancer location and location of all adenomas (p = 0.01) and of adenomas larger than 1 cm (p = 0.01). Adenomas of the right colon were more frequent in patients with right colon cancer (p = 0.008), and the same was true on the left colon (p = 0.002). The strong correlation between the locations of CRC and synchronous adenomas, namely risk adenomas, may point to a common early defect. It does also suggest that hemicolectomy may always be the surgery of choice for colon cancer.

Expression of PI3K/p-AKT/p-mTOR in gastric carcinoma and its correlation with clinicopathologic characteristics.

73 Background: The objective of this study was to explore the expression patterns of PI3K/p-AKT/p-mTOR in gastric cancer (GC) and its relationship with clinicopathological characteristics and thereby to understand the role of activated PI3K/AKT/mTOR pathway in the initiation and development of gastric cancer. Methods: Envision immunohistochemistry assay was used to examine the expression patterns of PI3K, p-AKT and p-mTOR in primary GC sites, metastatic lymph nodes and peritumoral mucosa among 50 patients who underwent radical gastrectomy for stage I-IV (M0) gastric cancer. Results: The PI3K, p-AKT and p-mTOR showed significantly higher expressions in primary tumor sites and metastatic lymph nodes as compared to that of the peritumoral mucosa. The study of the pathway components and clinicopathological characteristics revealed that p-AKT and p-mTOR expressions were selectively higher in primary tumors with less than 5 cm diameter. The PI3K, p-AKT and p-mTOR positive patients had shorter median survival time as compared to the patients negative for them (42.8 m vs. 57.0 m, 46.8 m vs. 55.9 m, 47.2 m vs. 53.0 m). However, the differences were not statistically significant. Conclusions: Activation of PI3K/AKT/mTOR pathway was associated with the development and prognosis of gastric cancer. The expression of PI3K/p-AKT/p-mTOR was correlated well with tumor specificity in gastric cancer and they might have some potential as promising targets for clinical therapy.

Overexpression of chemerin was associated with tumor angiogenesis and poor clinical outcome in squamous cell carcinoma of the oral tongue

The present study aimed to explore expression and clinical significance of chemerin, a newly discovered adipokine, in squamous cell carcinoma of the oral tongue (SCCOT). mRNA expression of chemerin in 19 pairs of fresh SCCOT samples matched with peritumoral mucosa tissues was quantified by real-time quantitative transcription polymerase chain reaction (qRT-PCR). Chemerin protein expression and microvessel density (MVD) were measured by immunohistochemistry on 147 cases of primary SCCOT specimen and their corresponding peritumoral noncancerous tissues. The relationship of chemerin expression with angiogenesis, clinicopathologic parameters, and cancer-related survival of patients was evaluated. Both qRT-PCR and immunohistochemistry results revealed that chemerin was overexpressed in SCCOT compared with peritumoral noncancerous tissues (P < 0.01). Overexpression of chemerin in SCCOT was significantly associated with poor differentiation, lymph node metastasis, and high clinical stage (P = 0.000, 0.012, and 0.015, respectively). In addition, overexpression of chemerin was positively related to MVD in SCCOT (r = 0.671, P = 0.002). SCCOT patients with overexpressed chemerin had a shorter cancer-related survival (P = 0.027). Moreover, multivariate survival analysis indicated that chemerin was an independent prognostic factor for SCCOT patients (P = 0.016). These results demonstrated that overexpression of chemerin in SCCOT was correlated with tumor angiogenesis and poor clinical outcomes of SCCOT patients. Our research implied that chemerin was a novel prognostic factor for SCCOT patients, and chemerin could be a new therapeutic target for regulating tumor angiogenesis and blocking tumor progression.

Su1987 Patients With Helicobacter pylori Negative Gastric Marginal Zone B-Cell Lymphoma (MZBCL) of MALT (MALT-Lymphoma) Reveal a Favourable Course of Disease

20-84 y, median 61.06, Hp+ 50%): 20 controls (Hp-negative, normal gastric mucosa), 20 AG and IM without gastric cancer, 18 patients with intestinal type gastric cancer and AG and IM in peritumoral mucosa (3 cm from the macroscopic tumor margin). For each group we performed the immunohistochemical assay of Ki67 and TUNEL and the molecular assess of PCNA and Bax/Bcl2. Statistical analysis was performed with Kruskal-Wallis, Mann-Whitney U test and Spearman Correlation rank test. Results. The expression of Ki67 and TUNEL in preneoplastic conditions was significantly increased compared to normal gastric mucosa (p,0.0001), however there was no difference in preneoplastic vs. peritumoral AG and IM (Table1). The expression of Bcl2 was decreased in all the groups as well as in preneoplastic vs peritumoral AG and IM (p,0.05, p,0.05). Grade of chronicity correlated positive with PCNA expression in preneoplastic AG and IM (r=0.56, p,0.01) and apoptosis in peritumoral AG and IM. Proliferation and apoptosis markers did not correlate with Hp status in our study population. Conclusions. In preneoplastic conditions we did not find any significant difference in the epithelial cell turnover. The suppression of Bcl2 gene needs to be considered in the context of the gastric mucosa, in all its cellular components and not only regarding the epithelial cell. Table 1. Differential expression of proliferation and apoptosis markers in the disease groups; NS: not significant, * Mann Whitney U test, ** KruskalWallis test.

Expression of a novel marker, Ubc9, in squamous cell carcinoma of the head and neck

Ubiquitin-conjugating enzyme (Ubc9) is a novel enzyme involved in posttranslational modification of cellular proteins. The objective of this study was to determine the expression of Ubc9 in squamous cell carcinoma of the head and neck (SCCHN). SCCHN specimens were stained with anti-Ubc9 antibodies, scored using a semiquantitative method, and statistically analyzed. Forty-six tumors were stained, 26 of which included adjacent mucosa. Ubc9 was significantly upregulated in the malignant and peritumoral tissues compared with mucosa from normal individuals. In peritumoral tissues, Ubc9 expression was detected in the basal and suprabasal epithelial layers. No Ubc9 was detected in epithelial cells in normal mucosa. These differences in Ubc9 expression were statistically significant (p < .0001). Tumor Ubc9 expression significantly correlated with clinical and pathologic stage. Ubc9 is significantly overexpressed in the primary SCCHN tumors and peritumoral mucosa compared with normal epithelial cells. These findings suggest that Ubc9 may play an important role in tumorigenesis and tumor progression of SCCHN.

Daunorubicin and daunorubicinol tissue concentrations in gastric cancer patients after local administration of a liposomal preparation

Background In order to study a model that maximizes gastric cancer tissue and lymph node exposure to antineoplastic drugs while simultaneously reducing their systemic bioavailability, we implemented a preliminary investigation of the disposition of a daunorubicin liposomal preparation (D) in gastric cancer patients by means of gastric submucosa injection. Method After a dose finding study, 12 patients (candidates for gastric resection because of gastric cancer) were studied by administering two doses of 50 mg of D (the highest tolerated dose) 1 week before surgery. Results Mean tissue concentrations at surgery were higher in cancer, normal non-injected peritumoral mucosa, and lymph node tissues than in serum or urine, in which there were only trace concentrations. While epigastric pain and histological modifications (inflammation and thickening of the gastric layers) were manifest in patients treated with 75 mg doses in the dose finding session, no clinical signs or symptoms of toxicity were recorded in those administered with 50 mg doses. Conclusions Local administration of D may allow it to reach high concentrations in normal non-injected peritumoral mucosa, and lymph nodes, while simultaneously avoiding significant systemic exposure and toxicity. This procedure could merit further investigation, in view of a possible use of anthracyclines against metastatic diffusion through the lymphatic system in gastric cancer patients who are candidates for gastric resection.

OVER EXPRESSION OF PLATELET-DERIVED ENDOTHELIAL CELL GROWTH FACTOR/THYMIDINE PHOSPHORYLASE IN PATIENTS WITH INTERSTITIAL CYSTITIS AND BLADDER CARCINOMA

We examined whether the expression of angiogenic factors, such as platelet-derived endothelial cell growth factor/thymidine phosphorylase (PDEGF/TP) and transforming growth factor-beta, in bladder tissue correlates with the severity of symptoms, such as urinary urgency and bladder pain, in patients with bladder carcinoma and interstitial cystitis. Bladder biopsy was performed in 32 patients with bladder carcinoma, including 19 with interstitial cystitis and 3 controls. Immunohistological staining for PDEGF/TP, transforming growth factor-beta and CD44 was performed in bladder specimens. PDEGF/TP in bladder tissues was also measured by enzyme-linked immunosorbent assay to examine the correlation of the expression of this factor with painful symptoms in patients with bladder carcinoma or interstitial cystitis. Immunohistochemical staining showed that PDEGF/TP stained in the submucosal layer beneath the basement membrane in bladder tissues of patients with interstitial cystitis and peritumoral areas of those with bladder carcinoma. In addition, PDEGF/TP, transforming growth factor-beta and CD44 stained in the same submucosal region and staining was observed at deeper submucosal levels in interstitial cystitis cases with severe rather than mild bladder pain. Quantitative analyses revealed that mean PDEGF/TP expression plus or minus standard deviation in tumor tissues of 10 patients with bladder carcinoma and pain was significantly higher than in tumor tissues of 22 with asymptomatic bladder carcinoma (129.3 +/- 70.7 versus 37.6 +/- 29.2 units per mg. protein). The mean expression of PDEGF/TP in peritumoral mucosa of patients with bladder carcinoma and pain was also significantly higher than in those with asymptomatic bladder carcinoma (75.5 +/- 42.1 versus 12.6 +/- 5.4 units per mg. protein). For interstitial cystitis mean expression in 6 patients with severe bladder pain was significantly higher than in 13 with moderate pain (79.2 +/- 59.2 versus 16.6 +/- 17.5 units per mg. protein). Mean expression in bladder tissues of controls was less than 2.3 units per mg. protein. These results suggest that angiogenic factors, such as PDEGF/TP and transforming growth factor-beta, may be involved in the inflammatory process to induce painful symptoms in patients with interstitial cystitis or bladder carcinoma. Proteoglycans such as CD44 may contribute to the presentation of these soluble angiogenic factors at the inflammation site.

Genetic marker analysis in head and neck cancer

Prognostication of head and neck cancer (HNCC) involves molecular identification of residual tumor cells, prediction of recurrence, distant metastases or secondary tumors and prediction of the sensitvity to therapy. Biomarkers of HNCC are mutations of p53, p16 and amplification of Cyclin D and E2F4. One hundred and fifty-two HNCC cases have been evaluated for p53, hMLH1, Cyclin D and p16 gene alterations using PCR-SSCP and Western blot analysis. P53 mutations of HNCC have been found in 37.5% of cases. However, 11% of the cases showed p53 mutations in the normal peritumoral mucosa suggesting "field cancerization" process. Mismatch-repair gene mutations (MMR: hMHL1 and hMSH2) occurred with 17 and 8.6% frequency, respectively, while E2F4 mutations were even more frequent (21.4%) in HNCC. Our data suggest that E2F4 overexpression can be caused by the inactivation of the p16 gene in HNCC, while its mutations are most probably associated to the mutations of the MMR genes. These molecular informations can help to predict the biological potential of HNCC as well as the probability of the development of secondary HNCCs.

Quantitative analysis of basic fibroblast growth factor and vascular endothelial growth factor in human colorectal cancer.

Tumour growth is angiogenesis dependent. Some authors suggest a prognostic role of microvessel count in colorectal cancer. We tested the role of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) in the switch to the angiogenic phenotype in 35 patients with colorectal cancer at different stages of disease. We evaluated the two angiogenic factors, by enzyme-linked immunosorbent assay (ELISA), in tumour, peritumoral mucosa, pathological mesenteric and peripheral blood. We used ten endoscopic intestinal biopsies and ten peripheral blood samples from healthy subjects as control. bFGF was significantly lower in tumour tissues and in peritumoral mucosas than in healthy mucosas, whereas VEGF was up-regulated in tumours but not in peritumoral mucosa. Both angiogenic factors were greatly increased in mesenteric blood. VEGF tumour and serum levels were significantly correlated with the stage of disease. bFGF tumour and serum concentration were not correlated with the stage of disease. The high levels of bFGF in mesenteric blood suggest that this growth factor might be abnormally released from tumour tissue and peritumoral mucosa and could function as an early effector in the switch to the angiogenic phenotype. In contrast, VEGF, whose levels show a significant correlation with the stage of disease, could act in a following step, supporting tumour progression.

Aberrant expression of nitric oxide synthase in human polyps, neoplastic colonic mucosa and surrounding peritumoral normal mucosa.

The expression of nitric oxide synthase (NOS) was studied by NAD(P)H diaphorase histochemical localization method in (i) individual cells of the normal colonic mucosa (n = 13) which served as control, (ii) colonic polyps (n = 14), (iii) colonic carcinoma (n = 20) and (iv) peritumoral mucosa (2 and 5 or 10 cm away from the tumor). Four of the tumor specimens had normal epithelium adjacent to the cancer, which thus served as an internal control. The expression of NOS activity in colon cancer was significantly reduced as compared to the control group of individuals (P < 0.004); undetectable in 25%, diminished in 45%, normal in 30%. On comparing the expression in normal mucosa and polyps there was a significant reduction of the expression in polyps (P < 0.027); undetectable in 14%, reduced in 35%, normal in 51%. When compared to the peritumoral mucosa at 2 and 10 cm the tumor showed a significant reduction in expression of NOS activity (P < 0.001 and P < 0.0001 respectively). There was no significant difference seen in the expression at 2 and 10 cm (P = 0.329). The peritumoral mucosa at a distance of 2 cm away from the tumor when compared to the control mucosa showed no significant difference (P = 1.000), although there is a tendency to a high normal expression of NOS activity in the mucosa at a distance of 2 cm. Similarly, there was no significant difference between the control mucosa and the peritumoral mucosa obtained at a distance of 10 cm (P = 0.383). The expression of NOS activity in all tissues examined was abolished by preincubation of tissue with the selective NOS inhibitor L-NMMA but not with D-NMMA. Our data showed extensive and significant reduction as identified by the NAD(P)H diaphorase method in the expression of NOS activity, thereby reflecting the activity of nitric oxide in colon cancer and colonic polyps. The generalized suppression of this activity, which precedes the onset of overt neoplasia, may be an important event in colon carcinogenesis. This aberrant expression could also be compatible with the selective advantage to either tumor promotion and metastatic progression or to tumoricidal activity.