Polysaccharide-fecal microbiota-based colon-targeted self-nanoemulsifying drug delivery system of curcumin for treating polycystic ovarian syndrome

The gut microbiome is involved in the pathogenesis of many diseases including polycystic ovarian syndrome (PCOS). Modulating the gut microbiome can lead to eubiosis and treatment of various metabolic conditions. However, there is no proper study assessing the delivery of microbial technology for the treatment of such conditions. The present study involves the development of guar gum-pectin-based solid self-nanoemulsifying drug delivery system (S-SNEDDS) containing curcumin (CCM) and fecal microbiota extract (FME) for the treatment of PCOS. The optimized S-SNEDDS containing FME and CCM was prepared by dissolving CCM (25 mg) in an isotropic mixture consisting of Labrafil M 1944 CS, Transcutol P, and Tween-80 and solidified using lactose monohydrate, aerosil-200, guar gum, and pectin (colon-targeted CCM solid self-nanoemulsifying drug delivery system [CCM-CT-S-SNEDDS]). Pharmacokinetic and pharmacodynamic evaluation was carried out on letrozole-induced female Wistar rats. The results of pharmacokinetic studies indicated about 13.11 and 23.48-fold increase in AUC of CCM-loaded colon-targeted S-SNEDDS without FME (CCM-CT-S-SNEDDS (WFME)) and CCM-loaded colon-targeted S-SNEDDS with FME [(CCM-CT-S-SNEDDS (FME)) as compared to unprocessed CCM. The pharmacodynamic study indicated excellent recovery/reversal in the rats treated with CCM-CT-S-SNEDDS low and high dose containing FME (group 13 and group 14) in a dose-dependent manner. The developed formulation showcasing its improved bioavailability, targeted action, and therapeutic activity in ameliorating PCOS can be utilized as an adjuvant therapy for developing a dosage form, scale-up, and technology transfer.

Synbiotics as Supplemental Therapy for the Alleviation of Chemotherapy-Associated Symptoms in Patients with Solid Tumours

Chemotherapy is still the first line of treatment for most cancer patients. Patients receiving chemotherapy are generally prone to infections, which result in complications, such as sepsis, mucositis, colitis, and diarrhoea. Several nutritional approaches have been trialled to counter the chemotherapy-associated side effects in cancer patients, but none have yet been approved for routine clinical use. One of the approaches to reduce or avoid chemotherapy-associated complications is to restore the gut microbiota. Gut microbiota is essential for the healthy functioning of the immune system, metabolism, and the regulation of other molecular responses in the body. Chemotherapy erodes the mucosal layer of the gastrointestinal tract and results in the loss of gut microbiota. One of the ways to restore the gut microbiota is through the use of probiotics. Probiotics are the ‘good’ bacteria that may provide health benefits if consumed in appropriate amounts. Some studies have highlighted that the consumption of probiotics in combination with prebiotics, known as synbiotics, may provide better health benefits when compared to probiotics alone. This review discusses the different nutritional approaches that have been studied in an attempt to combat chemotherapy-associated side effects in cancer patients with a particular focus on the use of pre-, pro- and synbiotics.

Biosimilars in Oncology: Latest Trends and Regulatory Status

Biologic-based medicines are used to treat a variety of diseases and account for around one-quarter of the worldwide pharmaceutical market. The use of biologic medications among cancer patients has resulted in substantial advancements in cancer treatment and supportive care. Biosimilar medications (or biosimilars) are very similar to the reference biologic drugs, although they are not identical. As patent protection for some of the most extensively used biologics begins to expire, biosimilars have the potential to enhance access and provide lower-cost options for cancer treatment. Initially, regulatory guidelines were set up in Europe in 2003, and the first biosimilar was approved in 2006 in Europe. Many countries, including the United States of America (USA), Canada, and Japan, have adopted Europe's worldwide regulatory framework. The use of numerous biosimilars in the treatment and supportive care of cancer has been approved and, indeed, the count is set to climb in the future around the world. However, there are many challenges associated with biosimilars, such as cost, immunogenicity, lack of awareness, extrapolation of indications, and interchangeability. The purpose of this review is to provide an insight into biosimilars, which include various options available for oncology, and the associated adverse events. We compare the regulatory guidelines for biosimilars across the world, and also present the latest trends and challenges in medical oncology both now and in the future, which will assist healthcare professionals, payers, and patients in making informed decisions, increasing the acceptance of biosimilars in clinical practice, increasing accessibility, and speeding up the health and economic benefits associated with biosimilars.

Gut Dysbiosis and Diabetic Foot Ulcer: Role of Probiotics

Diabetic foot ulcer (DFU) is a multifactorial disease and one of the complications of diabetes. The global burden of DFU in the health sector is increasing at a tremendous rate due to its cost management related to hospitalization, medical costs and foot amputation. Hence, to manage DFU/DWs, various attempts have been made, including treating wounds systematically/topically using synthetic drugs, herbal drugs, or tissue engineering based surgical dressings. However, less attention has been paid to the intrinsic factors that are also the leading cause of diabetes mellitus (DM) and its complications. One such factor is gut dysbiosis, which is one of the major causes of enhancing the counts of Gram-negative bacteria. These bacteria produce lipopolysaccharides, which are a major contributing factor toward insulin resistance and inflammation due to the generation of oxidative stress and immunopathy. These all lead to DM and DFU. Probiotics are the commercial form of beneficial gut microbes that are taken as nutraceuticals by people of all ages to improve gut immunity and prevent gut dysbiosis. However, the role of probiotics has been less explored in the management of DFU. Hence, the therapeutic potential of probiotics in managing DFU is fully described in the current review. This report covers the linkage between gut dysbiosis and DFU, sources of probiotics, the mechanisms of probiotics in DW healing, and the impact of probiotic supplementation in treating DFU. In addition, techniques for the stabilization of probiotics, market status, and patents related to probiotics have been also covered. The relevant data were gathered from PubMed, Scopus, Taylor and Francis, Science Direct, and Google Scholar. Our systematic review discusses the utilization of probiotic supplementation as a nutraceutical for the management of DFU.

An Appraisal of the Current Scenario in Vaccine Research for COVID-19

The recent coronavirus disease 2019 (COVID-19) outbreak has drawn global attention, affecting millions, disrupting economies and healthcare modalities. With its high infection rate, COVID-19 has caused a colossal health crisis worldwide. While information on the comprehensive nature of this infectious agent, SARS-CoV-2, still remains obscure, ongoing genomic studies have been successful in identifying its genomic sequence and the presenting antigen. These may serve as promising, potential therapeutic targets in the effective management of COVID-19. In an attempt to establish herd immunity, massive efforts have been directed and driven toward developing vaccines against the SARS-CoV-2 pathogen. This review, in this direction, is aimed at providing the current scenario and future perspectives in the development of vaccines against SARS-CoV-2.

Streptococcus Thermophilus UASt-09 Upregulates Goblet Cell Activity in Colonic Epithelial Cells to a Greater Degree than other Probiotic Strains

Probiotics have been widely used in maintaining gastrointestinal health, despite their actual mechanism remaining obscure. There are several hypotheses behind the beneficial effects of probiotics including the regulation of intestinal barrier function and improvement in immune responses in the gastrointestinal system. Multiple probiotics have been introduced in the market as effective dietary supplements in improving gastrointestinal integrity, but there are no or few studies that demonstrate their underlying mechanism. In the current study, we investigated and compared the efficacy of four probiotics (based on different bacterial species) in refining gastrointestinal health by improving mucus biosynthesis and intestinal immune response under in-vitro conditions. By analyzing the gene expression of mucus biosynthesis and intestinal immune response markers, we found that probiotic Streptococcus thermophilus UASt-09 showed promising potential in refining mucosal barrier and gastrointestinal health in human colonic epithelial cells, as compared to other commercial probiotics.

Identification of Key Pro-Survival Proteins in Isolated Colonic Goblet Cells of Winnie, a Murine Model of Spontaneous Colitis

BACKGROUND

Accumulating evidence suggests that the goblet cell-derived mucin-2 (Muc2) is a major component of the immune system and that perturbations in Muc2 lead to an ulcerative colitis-like phenotype. The animal model Winnie carries a missense mutation in Muc2 that causes Muc2 misfolding, accumulation in goblet cells, and ER stress. Excessive ER stress is a hallmark of many diseases, including ulcerative colitis, cancer, diabetes and Parkinson's disease. However, rather than committing to cell death, which is the typical outcome of unresolved ER stress, Winnie goblet cells are characterized by hyperproliferation, suggesting additional regulation of this cellular stress response.

METHODS

To elucidate the molecular mechanisms underlying ulcerative colitis in the Winnie model, we isolated goblet cells from Winnie and wild-type mice and used label-free quantitative proteomics and bioinformatics to understand the functional consequences of Muc2 misfolding and accumulation.

RESULTS

A large number of changes were identified that highlight a dramatic reprogramming of energy production, including enhanced utilization of butyrate, a key energy source of colonic cells. A major finding was the marked upregulation of the coiled-coil-helix-coiled-coil-helix domain proteins Chchd2, Chchd3, and Chchd6. In particular, we identified and confirmed the upregulation and nuclear translocation of Chchd2, a protein known to inhibit oxidative stress induced apoptosis.

CONCLUSIONS

This study is the first to apply proteome-level analysis to the preclinical Winnie model of ulcerative colitis. Identification of proteins and pathways affected in isolated Winnie goblet cells provides evidence for novel adaptive mechanisms underlying cell survival under conditions of chronic ER stress.

Bitter melon protects against ER stress in LS174T colonic epithelial cells

BACKGROUND

Bitter Melon (BM) has been used as a functional food in traditional Chinese and Indian medicine for many generations and has gained a great deal of attention due to its apparent benefits in moderating some of the pathogenic processes in a variety of inflammatory conditions. BM extract (BME) has been shown to possess strong anti-oxidant properties. In addition, it can ameliorate oxidative stress and potentially ER stress. There is increasing evidence that oxidative and ER stress are major contributors for intestinal secretory cell dysfunction which leads to local inflammation and disease pathogenesis that are hallmarks of inflammatory bowel diseases (IBD). Hence, the search for potential therapeutics against ER stress and oxidative stress in intestinal epithelial secretory cells may provide valuable resources for the management of IBD. The aim of the present study was to investigate the effects of BME in ameliorating ER stress in colonic epithelial cells.

METHODS

Human colonic adenocarcinoma LS174T cells were used for the assessment of BME effects on colonic epithelial cells in vitro. Cell viability was assessed using trypan blue exclusion and the effect of BME in ameliorating tunicamycin (TM)-induced ER stress was determined by analysing the mRNA expression of the common ER stress markers; ATF6, XBP1, GRP78, CHOP and PERK by quantitative RT-PCR and GRP78 and CHOP by western blot.

RESULTS

In the absence of ER stress, BME exhibited no cell toxicity up to 2.0% w/v and no significant effect on the basal mRNA expression of ER stress markers in LS174T cells. In contrast, pre-treatment of LS174T cells with BME followed by induction of ER stress resulted in a significant decrease in mRNA expression of ATF6, XBP1, GRP78, CHOP and PERK and protein expression of GRP78 and CHOP. Co-treatment during induction of ER stress and post- treatment following induction of ER Stress in LS174T cells resulted in a lower but still significant reduction in mRNA expression levels of most ER stress markers.

CONCLUSIONS

This is one of the first studies demonstrating the efficacy of BME in reducing expression of ER stress markers in colonic epithelial cells suggesting the potential of BME as a dietary intervention in ameliorating ER stress and oxidation in IBD. Interestingly, while the most significant effect was seen with pre-treatment of cells with BME there was a reduced but still significant effect when co-treated or even post-treated. This suggests that BME may even be effective in modulating ER stress in the face of an existing cell stress environment.

Heparins in ulcerative colitis: proposed mechanisms of action and potential reasons for inconsistent clinical outcomes

Current drug therapies for ulcerative colitis (UC) are not completely effective in managing moderate-to-severe UC and approximately 20% of patients with severe UC require surgical interventions. Heparins, polydisperse mixtures of non-anticoagulant and anticoagulant oligosaccharides, are widely used as anticoagulants. However, heparins are also reported to have anti-inflammatory properties. Unfractionated heparin was initially used in patients with UC for the treatment of rectal microthrombi. Surprisingly, it was found to be effective in reducing UC-associated symptoms. Since then, several pre-clinical and clinical studies have reported promising outcomes of heparins in UC. In contrast, some controlled clinical trials demonstrated no or only limited benefits, thus the potential of heparins for the treatment of UC remains uncertain. This review discusses potential mechanisms of action of heparins, as well as proposed reasons for their contradictory clinical effectiveness in the treatment of UC.

Orally Administered Enoxaparin Ameliorates Acute Colitis by Reducing Macrophage-Associated Inflammatory Responses

Inflammatory bowel diseases, such as ulcerative colitis, cause significant morbidity and decreased quality of life. The currently available treatments are not effective in all patients, can be expensive and have potential to cause severe side effects. This prompts the need for new treatment modalities. Enoxaparin, a widely used antithrombotic agent, is reported to possess anti-inflammatory properties and therefore we evaluated its therapeutic potential in a mouse model of colitis. Acute colitis was induced in male C57BL/6 mice by administration of dextran sulfate sodium (DSS). Mice were treated once daily with enoxaparin via oral or intraperitoneal administration and monitored for colitis activities. On termination (day 8), colons were collected for macroscopic evaluation and cytokine measurement, and processed for histology and immunohistochemistry. Oral but not intraperitoneal administration of enoxaparin significantly ameliorated DSS-induced colitis. Oral enoxaparin-treated mice retained their body weight and displayed less diarrhea and fecal blood loss compared to the untreated colitis group. Colon weight in enoxaparin-treated mice was significantly lower, indicating reduced inflammation and edema. Histological examination of untreated colitis mice showed a massive loss of crypt architecture and goblet cells, infiltration of immune cells and the presence of edema, while all aspects of this pathology were alleviated by oral enoxaparin. Reduced number of macrophages in the colon of oral enoxaparin-treated mice was accompanied by decreased levels of pro-inflammatory cytokines. Oral enoxaparin significantly reduces the inflammatory pathology associated with DSS-induced colitis in mice and could therefore represent a novel therapeutic option for the management of ulcerative colitis.

Fucoidan Extracts Ameliorate Acute Colitis

Inflammatory bowel diseases (IBD), such as ulcerative colitis and Crohn's disease, are an important cause of morbidity and impact significantly on quality of life. Overall, current treatments do not sustain a long-term clinical remission and are associated with adverse effects, which highlight the need for new treatment options. Fucoidans are complex sulphated, fucose-rich polysaccharides, found in edible brown algae and are described as having multiple bioactivities including potent anti-inflammatory effects. Therefore, the therapeutic potential of two different fucoidan preparations, fucoidan-polyphenol complex (Maritech Synergy) and depyrogenated fucoidan (DPF) was evaluated in the dextran sulphate sodium (DSS) mouse model of acute colitis. Mice were treated once daily over 7 days with fucoidans via oral (Synergy or DPF) or intraperitoneal administration (DPF). Signs and severity of colitis were monitored daily before colons and spleens were collected for macroscopic evaluation, cytokine measurements and histology. Orally administered Synergy and DPF, but not intraperitoneal DPF treatment, significantly ameliorated symptoms of colitis based on retention of body weight, as well as reduced diarrhoea and faecal blood loss, compared to the untreated colitis group. Colon and spleen weight in mice treated with oral fucoidan was also significantly lower, indicating reduced inflammation and oedema. Histological examination of untreated colitis mice confirmed a massive loss of crypt architecture and goblet cells, infiltration of immune cells and oedema, while all aspects of this pathology were alleviated by oral fucoidan. Importantly, in this model, the macroscopic changes induced by oral fucoidan correlated significantly with substantially decreased production of at least 15 pro-inflammatory cytokines by the colon tissue. Overall, oral fucoidan preparations significantly reduce the inflammatory pathology associated with DSS-induced colitis and could therefore represent a novel nutraceutical option for the management of IBD.

Can probiotic yogurt prevent diarrhoea in children on antibiotics? A double-blind, randomised, placebo-controlled study

OBJECTIVE

To estimate the efficacy of a probiotic yogurt compared to a pasteurised yogurt for the prevention of antibiotic-associated diarrhoea in children.

DESIGN AND SETTING

This was a multisite, randomised, double-blind, placebo-controlled clinical trial conducted between September 2009 and 2012. The study was conducted through general practices and pharmacies in Launceston, Tasmania, Australia.

PARTICIPANTS AND INTERVENTIONS

Children (aged 1-12 years) prescribed antibiotics, were randomised to receive 200 g/day of either yogurt (probiotic) containing Lactobacillus rhamnosus GG (LGG), Bifidobacterium lactis (Bb-12) and Lactobacillus acidophilus (La-5) or a pasteurised yogurt (placebo) for the same duration as their antibiotic treatment.

OUTCOMES

Stool frequency and consistency were recorded for the duration of treatment plus 1 week. Primary outcome was stool frequency and consistency, classified at different levels of diarrhoea severity. Due to the small number of cases of diarrhoea, comparisons between groups were made using Fisher's exact analysis.

RESULTS

72 children commenced and 70 children (36 placebo and 34 probiotic) completed the trial. There were no incidents of severe diarrhoea (stool consistency ≥6, ≥3 stools/day for ≥2 consecutive days) in the probiotic group and six in the placebo group (Fisher's exact p=0.025). There was also only one episode of minor diarrhoea (stool consistency ≥5, ≥2 stools/day for ≥2 days in the probiotic group compared to 21 in the placebo group (Fisher's exact p<0.001). The probiotic group reported fewer adverse events (1 had abdominal pain, 1 vomited and 1 had headache) than the placebo group (6 had abdominal pain, 4 had loss of appetite and 1 had nausea).

CONCLUSIONS

A yogurt combination of LGG, La-5 and Bb-12 is an effective method for reducing the incidence of antibiotic-associated diarrhoea in children.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry ACTRN12609000281291.

Glucocorticoids alleviate intestinal ER stress by enhancing protein folding and degradation of misfolded proteins

Dexamethasone suppresses ER stress in inflammatory bowel disease by promoting correct protein folding and ER-associated degradation.

Endoplasmic reticulum (ER) stress in intestinal secretory cells has been linked with colitis in mice and inflammatory bowel disease (IBD). Endogenous intestinal glucocorticoids are important for homeostasis and glucocorticoid drugs are efficacious in IBD. In Winnie mice with intestinal ER stress caused by misfolding of the Muc2 mucin, the glucocorticoid dexamethasone (DEX) suppressed ER stress and activation of the unfolded protein response (UPR), substantially restoring goblet cell Muc2 production. In mice lacking inflammation, a glucocorticoid receptor antagonist increased ER stress, and DEX suppressed ER stress induced by the N-glycosylation inhibitor, tunicamycin (Tm). In cultured human intestinal secretory cells, in a glucocorticoid receptor-dependent manner, DEX suppressed ER stress and UPR activation induced by blocking N-glycosylation, reducing ER Ca²⁺ or depleting glucose. DEX up-regulated genes encoding chaperones and elements of ER-associated degradation (ERAD), including EDEM1. Silencing EDEM1 partially inhibited DEX’s suppression of misfolding-induced ER stress, showing that DEX enhances ERAD. DEX inhibited Tm-induced MUC2 precursor accumulation, promoted production of mature mucin, and restored ER exit and secretion of Winnie mutant recombinant Muc2 domains, consistent with enhanced protein folding. In IBD, glucocorticoids are likely to ameliorate ER stress by promoting correct folding of secreted proteins and enhancing removal of misfolded proteins from the ER.

Exposure of colonic epithelial cells to oxidative and endoplasmic reticulum stress causes rapid potassium efflux and calcium influx

Endoplasmic reticulum (ER) stress and oxidative stress have recently been linked to the pathogenesis of inflammatory bowel diseases. Under physiological conditions, intestinal epithelial cells are exposed to ER and oxidative stress affecting the cellular ionic homeostasis. However, these altered ion flux 'signatures' during these stress conditions are poorly characterized. We investigated the kinetics of K(+) , Ca(2+) and H(+) ion fluxes during ER and oxidative stress in a colonic epithelial cell line LS174T using a non-invasive microelectrode ion flux estimation technique. ER and oxidative stress were induced by cell exposure to tunicamycin (TM) and copper ascorbate (CuAsc), respectively, from 1 to 24 h. Dramatic K(+) efflux was observed following acute ER stress with peak K(+) efflux being -30·6 and -138·7 nmolm(-2)  s(-1) for 10 and 50 µg ml(-1) , respectively (p < 0·01). TM-dependent Ca(2+) uptake was more prolonged with peak values of 0·85 and 2·68 nmol m(-2)  s(-1) for 10 and 50 µg ml(-1) TM, respectively (p < 0·02). Ion homeostasis was also affected by the duration of ER stress. Increased duration of TM treatment from 0 to 18 h led to increases in both K(+) efflux and Ca(2+) uptake. While K(+) changes were significantly higher at each time point tested, Ca(2+) uptake was significantly higher only after prolonged treatment (18 h). CuAsc also led to an increased K(+) efflux and Ca(2+) uptake. Functional assays to investigate the effect of inhibiting K(+) efflux with tetraethylammonium resulted in increased cell viability. We conclude that ER/oxidative stress in colonic epithelial cells cause dramatic K(+) , Ca(2+) and H(+) ion flux changes, which may predispose this lineage to poor stress recovery reminiscent of that seen in inflammatory bowel diseases.

ER stress and the unfolded protein response in intestinal inflammation

Endoplasmic reticulum (ER) stress is a phenomenon that occurs when excessive protein misfolding occurs during biosynthesis. ER stress triggers a series of signaling and transcriptional events known as the unfolded protein response (UPR). The UPR attempts to restore homeostasis in the ER but if unsuccessful can trigger apoptosis in the stressed cells and local inflammation. Intestinal secretory cells are susceptible to ER stress because they produce large amounts of complex proteins for secretion, most of which are involved in mucosal defense. This review focuses on ER stress in intestinal secretory cells and describes how increased protein misfolding could occur in these cells, the process of degradation of misfolded proteins, the major molecular elements of the UPR pathway, and links between the UPR and inflammation. Evidence is reviewed from mouse models and human inflammatory bowel diseases that ties ER stress and activation of the UPR with intestinal inflammation, and possible therapeutic approaches to ameliorate ER stress are discussed.

STAT4 isoforms differentially regulate Th1 cytokine production and the severity of inflammatory bowel disease

STAT4, a critical regulator of inflammation in vivo, can be expressed as two alternative splice forms, a full-length STAT4alpha, and a STAT4beta isoform lacking a C-terminal transactivation domain. Each isoform is sufficient to program Th1 development through both common and distinct subsets of target genes. However, the ability of these isoforms to mediate inflammation in vivo has not been examined. Using a model of colitis that develops following transfer of CD4(+) CD45RB(high) T cells expressing either the STAT4alpha or STAT4beta isoform into SCID mice, we determined that although both isoforms mediate inflammation and weight loss, STAT4beta promotes greater colonic inflammation and tissue destruction. This correlates with STAT4 isoform-dependent expression of TNF-alpha and GM-CSF in vitro and in vivo, but not Th1 expression of IFN-gamma or Th17 expression of IL-17, which were similar in STAT4alpha- and STAT4beta-expressing T cells. Thus, higher expression of a subset of inflammatory cytokines from STAT4beta-expressing T cells correlates with the ability of STAT4beta-expressing T cells to mediate more severe inflammatory disease.

Characterization of tumour-infiltrating lymphocytes and apoptosis in colitis-associated neoplasia: comparison with sporadic colorectal cancer

The development of colorectal cancer is a major complication for patients with chronic idiopathic colitis. Colitis-associated tumours tend to occur at a younger age and be more aggressive than sporadic colorectal cancers. While we have previously associated the presence of tumour-infiltrating lymphocytes (TILs) and increased apoptosis in sporadic colorectal cancer with high-level microsatellite instability and improved prognosis, little is known of the relationship between these variables in colitis-associated colorectal cancer. The aim of this study was to correlate TILs and tumour cell apoptosis in colitis-associated neoplasms stratified according to microsatellite instability. Twenty tumour and 11 dysplastic samples resected from 21 patients with long-standing colitis were analysed for microsatellite instability at 10 microsatellite markers. TIL distribution (CD3, CD8) and function (granzyme B) were quantified by immunohistochemistry. Neoplastic cell apoptosis was assessed using the M30 CytoDEATH antibody. These findings were compared with 40 microsatellite stable (MSS) sporadic colorectal cancers previously evaluated for TILs and neoplastic apoptosis. Low-level microsatellite instability was found in 1/20 colitis-associated tumours. All other colitis-associated lesions were designated MSS. CD3(+) and CD8(+) TIL counts were significantly higher in colitis-associated lesions compared with MSS sporadic colorectal cancer (p < 0.0001, p = 0.001 respectively). Despite their higher TIL density, colitis-associated tumours were more likely to present late (Dukes' stage C or D) (p = 0.02). Functionally, colitis-associated TILs demonstrated significantly less granzyme B expression compared to sporadic cancers (p = 0.002). The level of tumour cell apoptosis was similar between the two groups (sporadic, 1.53%; colitis cancers, 1.45%). In conclusion, MSS colitis-associated tumours have a higher prevalence of CD3(+)/CD8(+) TILs but no associated increase in tumour cell killing by apoptosis. Unlike cytotoxic T cells in sporadic colorectal cancer, TILs do not appear to enhance the prognosis of colitis-associated colorectal cancer. This may be related to an impairment of granzyme B expression within these lesions.