Local calprotectin production in colorectal cancer and polyps--active neutrophil recruitment in carcinogenesis

Tumor-Associated Neutrophils in Colorectal Cancer Development, Progression and Immunotherapy

The colorectal-cancer (CRC) incidence rate and mortality have remained high for several years. In recent years, immune-checkpoint-inhibitor (ICI) therapy has rapidly developed. However, it is only effective in a few CRC patients with microsatellite-instability-high (MSI-H) or mismatch-repair-deficient (dMMR) CRC. How to improve the efficiency of ICI therapy in CRC patients with microsatellite stability (MSS) remains a huge obstacle. Tumor-associated neutrophils (TANs), which are similar to macrophages, also have N1 and N2 phenotypes. They can be recruited and polarized through different cytokines or chemokines, and then play an antitumor or tumor-promoting role. In CRC, we find that the prognostic significance of TANs is still controversial. In this review, we describe the antitumor regulation of TANs, and their mechanism of promoting tumor progression by boosting the transformation of inflammation into tumors, facilitating tumor-cell proliferation, metastasis and angiogenesis. The targeting of TANs combined with ICIs may be a new treatment model for CRC. Relevant animal experiments have shown good responses, and clinical trials have also been carried out in succession. TANs, as “assistants” of ICI treatment, may become the key to the success of CRC immunotherapy, although no significant results have been obtained.

Neutrophil Extracellular Traps in Digestive Cancers: Warrior or Accomplice

Characterized as a complex of extracellular DNA fibers and granule proteins, neutrophil extracellular traps (NETs) are generated specifically by neutrophils which play a critical role in host defense and immune regulation. NETs have been initially found crucial for neutrophil anti-microbial function. Recent studies suggest that NETs are involved in tumorigenesis and cancer progression. However, the function of NETs in cancer remains unclear, which might be due to the variation of research models and the heterogeneity of cancers. Although most of malignant tumors have similar biological behaviors, significant differences indeed exist in various systems. Malignant tumors of the digestive system cause the most incidence and mortality of cancer worldwide. In this review, we would focus on research developments on NETs in digestive cancers to provide insights on their role in digestive cancer progression and future research directions.

Appendiceal inflammation in colectomy is independently correlated with early pouchitis following ileal pouch anal anastomosis in ulcerative colitis and indeterminate colitis

BACKGROUND

Appendiceal inflammation in colectomy is one of the histologic predictors of pouchitis in ulcerative colitis (UC) following ileal pouch anal anastomosis (IPAA). Fecal calprotectin level has been shown to increase 2 months prior to the onset of pouchitis. We evaluated whether inflammation and calprotectin expression in appendiceal specimens correlate with early-onset pouchitis in UC and indeterminate colitis (IC).

MATERIALS AND METHODS

IPAA (2000-2018) cases with appendix blocks available in colectomy specimens were identified (n = 93, 90 UC, 3 IC). Histologic features thought to predict pouchitis were evaluated. The degree of appendiceal inflammation was scored. Calprotectin immunostain was performed on the appendix blocks and the extent of mucosal staining was quantified. Electronic medical records were reviewed for demographics, smoking history, clinical pouchitis, time of onset of pouchitis, and clinical and endoscopic components of the Pouchitis Disease Activity Index (PDAI) score. Follow-up pouch biopsies were reviewed and scored to generate histologic PDAI score, when available.

RESULTS

Among the patients with clinical pouchitis (n = 73), moderate to severe appendiceal inflammation independently correlated with earlier pouchitis compared to no/mild inflammation (median time to pouchitis 12.0 vs. 23.8, log rank p = 0.016). Calprotectin staining correlated with inflammatory scores of the appendix (Spearman's rho, r = 0.630, p < 0.001) but not with early pouchitis (p > 0.05).

CONCLUSIONS

The presence of moderate to severe appendiceal inflammation at the time of colectomy was associated with a shorter time to pouchitis following IPAA. Calprotectin immunostain may be used to demonstrate the presence of inflammation in the appendix but its role in predicting early pouchitis remains limited.

Tissue mRNA for S100A4, S100A6, S100A8, S100A9, S100A11 and S100P Proteins in Colorectal Neoplasia: A Pilot Study

S100 proteins are involved in the pathogenesis of sporadic colorectal carcinoma through different mechanisms. The aim of our study was to assess tissue mRNA encoding S100 proteins in patients with non-advanced and advanced colorectal adenoma. Mucosal biopsies were taken from the caecum, transverse colon and rectum during diagnostic and/or therapeutic colonoscopy. Another biopsy was obtained from adenomatous tissue in the advanced adenoma group. The tissue mRNA for each S100 protein (S100A4, S100A6, S100A8, S100A9, S100A11 and S100P) was investigated. Eighteen biopsies were obtained from the healthy mucosa in controls and the non-advanced adenoma group (six individuals in each group) and thirty biopsies in the advanced adenoma group (ten patients). Nine biopsies were obtained from advanced adenoma tissue (9/10 patients). Significant differences in mRNA investigated in the healthy mucosa were identified between (1) controls and the advanced adenoma group for S100A6 (p = 0.012), (2) controls and the non-advanced adenoma group for S100A8 (p = 0.033) and (3) controls and the advanced adenoma group for S100A11 (p = 0.005). In the advanced adenoma group, differences between the healthy mucosa and adenomatous tissue were found in S100A6 (p = 0.002), S100A8 (p = 0.002), S100A9 (p = 0.021) and S100A11 (p = 0.029). Abnormal mRNA expression for different S100 proteins was identified in the pathological adenomatous tissue as well as in the morphologically normal large intestinal mucosa.

Improving the diagnosis of high grade and stage bladder cancer by detecting increased urinary calprotectin expression in tumor tissue and tumor-associated inflammatory response

PURPOSE

To investigate whether measurement of urinary calprotectin can serve as a biomarker in the diagnosis of primary bladder cancer and to confirm its diagnostic role in determining high grade and stage disease.

MATERIALS AND METHODS

Urinary calprotectin was measured in spot urine samples from patients with primary bladder cancer and control subjects. To confirm levels in urine, tissue samples were also obtained from bladder tumor and healthy trigone of bladder by transurethral resection in both groups. Finally, calprotectin levels in tissue and urine of the patients and control subjects were compared and their diagnostic potential was investigated in high grade and stage bladder cancers.

RESULTS

Of 82 participants, 52 were patients with bladder cancer and 30 were control subjects. The two groups were comparable in terms of age, smoking status, and comorbidities. Tissue and urinary calprotectin levels were significantly higher in the bladder cancer group. In subgroup analyses, urinary calprotectin levels were significantly higher in patients with high-grade, muscle-invasive tumors. After receiver operating characteristic analyses, the sensitivity and specificity of urinary calprotectin was 100% and 96.7%, respectively, in the diagnosis of primary bladder cancer. High grade and stage bladder cancers were detected with sensitivity and specificity of 70% and 74.2%, and 80% and 84.8%, respectively.

CONCLUSIONS

Urinary calprotectin may be a valuable parameter in the diagnosis of primary bladder cancer with high sensitivity and specificity. Furthermore, it may be useful in the prediction of high grade and stage disease. However, more investigations are needed.

Fecal Calprotectin

Calprotectin is a 36kDa member of the S100 family of proteins. It is derived predominantly from neutrophils and has direct antimicrobial effects and a role within the innate immune response. Calprotectin is found in various body fluids in proportion to the degree of any existing inflammation and its concentration in feces is about six times that of plasma. Measurement of fecal calprotectin is a useful surrogate marker of gastrointestinal inflammation. It has a high negative predictive value in ruling out inflammatory bowel disease (IBD) in undiagnosed, symptomatic patients and a high sensitivity for diagnosing the disease making it useful as a tool for prioritising endoscopy. In patients with known IBD, fecal calprotectin can be a useful tool to assist management, providing evidence of relapse or mucosal healing to enable therapy to be intensified or reduced. There are a number of commercial calprotectin assays with marked difference in performance as judged by external quality assessment and at present no standardised reference material exists. Various factors may affect results including age, medication and day to day variation. Laboratories should therefore be mindful of the characteristics of their own assay and factors that may affect results.

Beyond Histological Remission: Intramucosal Calprotectin as a Potential Predictor of Outcomes in Ulcerative Colitis

BACKGROUND AND AIMS

Histological remission and low faecal calprotectin are positive prognostic factors in ulcerative colitis [UC]. Intramucosal calprotectin [iMC], which can be readily determined by immunohistochemistry, has not so far been evaluated as a predictor of outcome in UC. We aimed to investigate the relationship between iMC and clinical, endoscopic, and histological measures of remission in UC, and the independent prognostic value of iMC.

METHODS

Ambulant patients with UC were recruited for a study comparing clinical activity indices. Sigmoidoscopy and biopsy were performed at the index visit. Clinical, endoscopic, and histological activity were scored and iMC semi-quantitatively measured using immunohistochemistry for the S100A8/9 heterodimer on colonic biopsies, scored as the mean number of positive cells in five high-power fields [HPF]. At the end of follow-up [6 years], data on steroid use, hospitalisation, and colectomy ['adverse outcomes'] were collected.

RESULTS

iMC was determined in 83 patients and 20 controls, and correlated with clinical, endoscopic, and histological activity [r = 0.51, 0.65, 0.53, p > 0.001, respectively]. iMC was lowest (median 2.4, interquartile range [IQR]: 5.2-5, p < 0.001) in patients with concordance between clinical, endoscopic, and histological remission. Median iMC > 5/HPF was associated with adverse outcome (hazard ratio [HR] 3.36, confidence interval [CI] 1.58, 7.15, p < 0.001). Only 53%, 33%, and 25% of patients in histological remission with iMC > 5 cells/HPF avoided an adverse outcome after 1, 3, and 6 years, respectively.

CONCLUSIONS

iMC was lowest in patients with concordant clinical, endoscopic, and histological remission. Median iMC > 5/HPF was associated with adverse outcomes despite histological remission. Therefore iMC is a potentially useful independent marker of activity.

Response to Infliximab in Crohn's Disease: Genetic Analysis Supporting Expression Profile

Substantial proportion of Crohn's disease (CD) patients shows no response or a limited response to treatment with infliximab (IFX) and to identify biomarkers of response would be of great clinical and economic benefit. The expression profile of five genes (S100A8-S100A9, G0S2, TNFAIP6, and IL11) reportedly predicted response to IFX and we aimed at investigating their etiologic role through genetic association analysis. Patients with active CD (350) who received at least three induction doses of IFX were included and classified according to IFX response. A tagging strategy was used to select genetic polymorphisms that cover the variability present in the chromosomal regions encoding the identified genes with altered expression. Following genotyping, differences between responders and nonresponders to IFX were observed in haplotypes of the studied regions: S100A8-S100A9 (rs11205276^*G/rs3014866^*C/rs724781^*C/rs3006488^*A; P = 0.05); G0S2 (rs4844486^*A/rs1473683^*T; P = 0.15); TNFAIP6 (rs11677200^*C/rs2342910^*A/rs3755480^*G/rs10432475^*A; P = 0.10); and IL11 (rs1126760^*C/rs1042506^*G; P = 0.07). These differences were amplified in patients with colonic and ileocolonic location for all but the TNFAIP6 haplotype, which evidenced significant difference in ileal CD patients. Our results support the role of the reported expression signature as predictive of anti-TNF outcome in CD patients and suggest an etiological role of those top-five genes in the IFX response pathway.

Clinical and histopathological correlations of fecal calprotectin release in colorectal carcinoma

AIM: To determine calprotectin release before and after colorectal cancer operation and compare it to tumor and histopathological parameters.

METHODS: The study was performed on patients with diagnosed colorectal cancer admitted for operation. Calprotectin was measured in a single stool sample before and three months after the operation using an enzyme-linked immunosorbent assay (ELISA). Calprotectin levels greater than or equal to 50 μg/g were considered positive. The compliance for collecting stool samples was assessed and the value of calprotectin was correlated to tumor and histopathological parameters of intra- and peri-tumoral inflammation. Surgical specimens were fixed in neutral buffered formalin and stained with hematoxylin and eosin. Staging was performed according to the Dukes classification system and the 7^th edition tumor node metastasis classification system. Intra- and peri-tumoral inflammation was graded according to the Klintrup criteria. Immunohistochemical quantification was performed for MPO, CD45R0, TIA-1, CD3, CD4, CD8, CD57, and granzyme B. Statistical significance was measured using Wilcoxon signed rank test, Kruskal Wallis test and Spearman’s rank correlation coefficient as appropriate.

RESULTS: Between March 2009 and May 2011, 80 patients with colorectal cancer (46 men and 34 women, with mean age of 71 ± 11.7 years old) were enrolled in the study. Twenty-six patients had rectal carcinoma, 29 had left-side tumors, 23 had right-side tumors, and 2 had bilateral carcinoma. In total, 71.2% of the patients had increased levels of calprotectin before the operation (median 205 μg/g, range 50-2405 μg/g) and experienced a significant decrease three months after the operation (46 μg/g, range 10-384 μg/g, P < 0001). The compliance for collecting stool samples was 89.5%. Patients with T3 and T4 tumors had significantly higher values than those with T1 and T2 cancers (P = 0.022). For all other tumor parameters (N, M, G, L, V, Pn) and location, no significant difference in calprotectin concentration was found. Furthermore, the calprotectin levels and histological grading of both peri- and intra-tumoral inflammation was not correlated. Additional testing with specific markers for lymphocytes and neutrophils also revealed no statistically significant correlation.

CONCLUSION: Fecal calprotectin decreases significantly after colorectal cancer operation. Its value depends exclusively on the individual T-stage, but not on other tumor or histopathological parameters.

The use of fecal calprotectin as a biomarker in gastrointestinal disease

Abdominal discomfort including pain, bloating and diarrhea is common. It often arises from functional gastrointestinal disorders but may indicate inflammatory bowel disease (IBD). Calprotectin is an abundant neutrophil protein that is released during inflammation. When measured in feces, it can be used to differentiate between non-organic and inflammatory intestinal disorders, especially to identify IBD. Fecal calprotectin might also be useful to monitor patients with IBD under treatment and to predict the risk of recurrence of active disease prior to clinical relapse. The use of fecal calprotectin has been investigated in a number of gastrointestinal disorders other than IBD, for example, as screening test for colorectal cancer but the available data are limited. This article summarizes the current literature on the use of fecal calprotectin in clinical practice.

Expression of neutrophil gelatinase-associated lipocalin in colorectal neoplastic progression: a marker of malignant potential?

Background:

Neutrophil gelatinase-associated lipocalin (NGAL) has a diverse functional repertoire, involved in the innate immune response as well as cell growth and differentiation. Expression has been linked to malignant disease development and progression.

Methods:

Neutrophil gelatinase-associated lipocalin expression was assessed immunohistochemically in 98 colorectal neoplastic lesions (52 cancer polyps (CaPs) and 46 sporadic adenoma/adjacent normal mucosa paired specimens) to investigate association with adenoma progression and early colorectal carcinogenesis.

Results:

Within CaPs, all adenomatous and carcinomatous epithelium expressed NGAL, with 92% (43 out of 47) and 58% (19 out of 33) epithelial positivity, respectively, as well as positive stromal cell expression. This was significantly increased compared with normal mucosal epithelium (P=0.0001). Neutrophil gelatinase-associated lipocalin positivity was also identified in sporadic low-grade adenomas, in both the epithelial and stromal compartments as compared with adjacent normal mucosa (P=0.0001 and 0.0002), and this increased along with adenoma size >1 cm (P=0.03).

Conclusion:

Neutrophil gelatinase-associated lipocalin is expressed by the majority of human neoplastic colorectal lesions. This phenotypic switch occurs at an early stage in neoplastic progression with clear differential expression between normal mucosa and adenomatous polyps, rather than further downstream in disease progression at the adenoma–carcinoma transformation. Thus, NGAL expression is not a useful biomarker for determining disease progression from adenomatous to malignant colorectal neoplasia.

Presence of S100A9-positive inflammatory cells in cancer tissues correlates with an early stage cancer and a better prognosis in patients with gastric cancer

Background

S100A9 was originally discovered as a factor secreted by inflammatory cells. Recently, S100A9 was found to be associated with several human malignancies. The purpose of this study is to investigate S100A9 expression in gastric cancer and explore its role in cancer progression.

Methods

S100A9 expression in gastric tissue samples from 177 gastric cancer patients was assessed by immunohistochemistry. The expression of its dimerization partner S100A8 and the S100A8/A9 heterodimer were also assessed by the same method. The effect of exogenous S100A9 on motility of gastric cancer cells AGS and BGC-823 was then investigated.

Results

S100A9 was specifically expressed by inflammatory cells such as macrophages and neutrophils in human gastric cancer and gastritis tissues. Statistical analysis showed that a high S100A9 cell count (> = 200) per 200x magnification microscopic field in cancer tissues was predictive of early stage gastric cancer. High S100A9-positive cell count was negatively correlated with lymph node metastasis (P = 0.009) and tumor invasion (P = 0.011). S100A9 was identified as an independent prognostic predictor of overall survival of patients with gastric cancer (P = 0.04). Patients with high S100A9 cell count were with favorable prognosis (P = 0.021). Further investigation found that S100A8 distribution in human gastric cancer tissues was similar to S100A9. However, the number of S100A8-positive cells did not positively correlate with patient survival. The inflammatory cells infiltrating cancer were S100A8/A9 negative, while those in gastritis were positive. Furthermore, exogenous S100A9 protein inhibited migration and invasion of gastric cancer cells.

Conclusions

Our results suggested S100A9-positive inflammatory cells in gastric cancer tissues are associated with early stage of gastric cancer and good prognosis.