Early disturbance of microvascular function precedes chemotherapy-induced intestinal injury

Review on the effect of chemotherapy on the intestinal barrier: Epithelial permeability, mucus and bacterial translocation

Chemotherapy kills fast-growing cells including gut stem cells. This affects all components of the physical and functional intestinal barrier, i.e., the mucus layer, epithelium, and immune system. This results in an altered intestinal permeability of toxic compounds (e.g., endotoxins) as well as luminal bacterial translocation into the mucosa and central circulation. However, there is uncertainty regarding the relative contributions of the different barrier components for the development of chemotherapy-induced gut toxicity. This review present an overview of the intestinal mucosal barrier determined with various types of molecular probes and methods, and how they are affected by chemotherapy based on reported rodent and human data. We conclude that there is overwhelming evidence that chemotherapy increases bacterial translocation, and that it affects the mucosal barrier by rendering the mucosa more permeable to large permeability probes. Chemotherapy also seems to impede the intestinal mucus barrier, even though this has been less clearly evaluated from a functional standpoint but certainly plays a role in bacteria translocation. Combined, it is however difficult to outline a clear temporal or succession between the different gastrointestinal events and barrier functions, especially as chemotherapy-induced neutropenia is also involved in intestinal immunological homeostasis and bacterial translocation. A thorough characterization of this would need to include a time dependent development of neutropenia, intestinal permeability, and bacterial translocation, ideally after a range of chemotherapeutics and dosing regimens.

Lymphangiocrine signals are required for proper intestinal repair after cytotoxic injury

The intestinal epithelium undergoes continuous renewal and has an exceptional capacity to regenerate after injury. Maintenance and proliferation of intestinal stem cells (ISCs) are regulated by their surrounding niche, largely through Wnt signaling. However, it remains unclear which niche cells produce signals during different injury states, and the role of endothelial cells (ECs) as a component of the ISC niche during homeostasis and after injury has been underappreciated. Here, we show that lymphatic endothelial cells (LECs) reside in proximity to crypt epithelial cells and secrete molecules that support epithelial renewal and repair. LECs are an essential source of Wnt signaling in the small intestine, as loss of LEC-derived Rspo3 leads to a lower number of stem and progenitor cells and hinders recovery after cytotoxic injury. Together, our findings identify LECs as an essential niche component for optimal intestinal recovery after cytotoxic injury.

Chemotherapy induced small bowel obstruction in small cell lung cancer

Lung cancer is the leading cause of cancer related death in men and the second cause in women worldwide. We describe a case of a 51- year old lady with small cell lung cancer who developed small bowel obstruction following chemotherapy with cisplatin and etoposide. Abdominal CT scan showed changes confined to the jejunum and proximal ileum with diffuse mural thickening and hyper-attenuation of the mucosa with sparing of the terminal ileum, caecum and colon. Her condition improved with conservative management and intravenous antibiotics.

The beneficial influence of rhubarb on 5-fluorouracil-induced ileal mucositis and the combined role of aquaporin-4, tumour necrosis factor-α, nuclear factor-kappa B & matrix metalloproteinase-9 in rat model: histological study

A 5-fluorouracil (5-FU) is used for cancer treatment despite its cytotoxic sequelae on healthy cells, especially the rapid proliferating ones. Intestinal mucositis is one of the most frequent chemotherapeutic debilitating sequelae. Rhubarb (Rh), an ancient herb, is known for its curing effect on gastrointestinal complications. This study aims to detect the role of aquaporin-4 (AQP-4), tumour necrosis factor-α (TNF-α), nuclear factor-kappa B (NF-κB), and matrix metalloproteinase-9 (MMP-9) in 5-FU-induced ileal histological and biochemical changes and the potential therapeutic effect of Rh water extract on these changes in rats. A 45 rats were divided into 3 groups; control, 5-FU (single intraperitoneal injection of 150 mg/kg/rat) and Rh-treated (oral 20 mg/kg/day/rat for 8 days). The change in animals’ weight, incidence of diarrhoea and AQP-4 and TNF-α values in ileal homogenates were measured. Ileal sections were subjected to hematoxylin and eosin stain, periodic acid Schiff (PAS)-reaction and MMP-9, NF-κB and AQP-4 immunohistochemical staining. A 5-FU group revealed marked ileal mucosal damage associated with a significant decrease in the mean body weight, AQP-4 level and area percent of PAS and AQP-4 positive reaction. Significant increase in the mean incidence of diarrhoea, TNF-α value and area percent of MMP-9 and NF-κB was detected. These changes were significantly corrected with Rh administration. A 5-FU resulted in severe ileal mucositis through TNF-α, NF-κB, MMP-9, and AQP-4 disturbances. Rh treatment was highly effective in preventing such mucositis.

Intestinal atresia following chemotherapy, presenting as superior mesenteric artery syndrome: A case report

Multi-agent chemotherapy is recognized as the most common and effective treatment for Burkitt lymphoma, and intestinal mucosal injury is a common gastrointestinal complication following intensive chemotherapy. The aim of the present study was to describe a case of non-Hodgkin lymphoma with intestinal obstruction after chemotherapy in a young adult. The patient presented with aggravated vomiting during the second session of chemotherapy, which was initially attributed to superior mesenteric artery syndrome. However, following surgical intervention, the symptom was proven to be due to extreme intestinal stenosis in the ascending part of the duodenum. The patient underwent duodenojejunectomy and end-to-side anastomosis, and he recovered well from the operation. Although intestinal perforation and hemorrhage induced by chemotherapy have been previously reported sporadically, to the best of our knowledge, this is the first case report of distal duodenal obstruction due to intestinal atresia induced by polychemotherapy for lymphoma. We herein analyze the possible underlying reasons for the intestinal atresia and review the clinical and pathological characteristics of previously published relevant studies. The present findings may be helpful for increasing clinical awareness of this type of complication, as well as improving the management of patients treated with cytotoxic chemotherapeutic agents.

β-Arrestin1 inhibits chemotherapy-induced intestinal stem cell apoptosis and mucositis

The mechanism of chemotherapy-induced gastrointestinal (GI) syndrome (CIGIS) is still controversial, and it is unclear whether chemotherapy induces intestinal stem cell (ISC) apoptosis. β-Arrestins are regulators and mediators of G protein-coupled receptor signaling in cell apoptosis, division and growth. In this study, we aimed to investigate whether chemotherapy induces ISC apoptosis to contribute to mucositis in CIGIS and whether β-arrestin1 (β-arr1) is involved in this apoptosis. Different chemotherapeutic agents were used to generate a CIGIS model. Lgr5-EGFP-IRES-creERT2^+/− knock-in mice were used as a CIGIS model to investigate ISC apoptosis. β-arr1 knockout mice were used to determine whether β-arr1 is involved in the apoptosis in CIGIS. Intestinal histology was performed, the ISC apoptosis was analyzed and the mucosal barrier was examined. The effects of β-arr1 in apoptosis were investigated in the samples from humans and mice as well as in cell lines. Here, we demonstrate that chemotherapy induced intestinal mucositis by promoting crypt cell apoptosis, especially in Lgr5+ stem cells and Paneth cells but not in goblet cells, epithelial cells or vascular endothelial cells. Furthermore, β-arr1 deficiency exacerbated the Lgr5+ stem cell apoptosis, but not Paneth cell apoptosis, in CIGIS. In addition, the data showed that β-arr1 reduced the chemotherapy-induced Lgr5+ stem cell apoptosis by inhibiting endoplasmic reticulum stress-mediated mitochondrial apoptotic signaling. Our study indicates that β-arr1 inhibits chemotherapy-induced ISC apoptosis to alleviate intestinal mucositis in CIGIS.

Impact of intra-operative intraperitoneal chemotherapy on organ/space surgical site infection in patients with gastric cancer

BACKGROUND

Various risk factors for surgical site infection (SSI) have been identified such as age, overweight, duration of surgery, blood loss, etc. Intraperitoneal chemotherapy during surgery is a common procedure in patients with gastric cancer, yet its impact on SSI has not been evaluated.

AIM

To evaluate whether intra-operative intraperitoneal chemotherapy is a key risk factor for organ/space SSI in patients with gastric cancer.

METHODS

All patients with gastric cancer who underwent surgery at the Department of Gastrointestinal Surgery between January 2008 and December 2013 were studied. The organ/space SSI rates were compared between patients who received intra-operative intraperitoneal chemotherapy and patients who did not receive intra-operative intraperitoneal chemotherapy, and the risk factors for organ/space SSI were analysed by univariate and multi-variate regression analyses. The microbial causes of organ/space SSI were also identified.

FINDINGS

Of the eligible 845 patients, 356 received intra-operative intraperitoneal chemotherapy, and the organ/space SSI rate was higher in these patients compared with patients who did not receive intra-operative intraperitoneal chemotherapy (9.01% vs 3.88%; P = 0.002). Univariate analysis confirmed the significance of this finding (odds ratio 2.443; P = 0.003). As a result, hospital stay was increased in patients who received intra-operative intraperitoneal chemotherapy {mean 20.91 days [95% confidence interval (CI) 19.76-22.06] vs 29.72 days (95% CI 25.46-33.99); P = 0.000}. The results also suggested that intra-operative intraperitoneal chemotherapy may be associated with more Gram-negative bacterial infections.

CONCLUSION

Intra-operative intraperitoneal chemotherapy is a significant risk factor for organ/space SSI in patients with gastric cancer.

Chemotherapy mediates intestinal injury via p53/p53 upregulated modulator of apoptosis (PUMA) signaling pathway

OBJECTIVE

The aim of this study was to investigate the potential mechanism and signaling pathway involved in chemotherapy-induced intestinal mucosal injury (CIMI), which is a common physiopathological problem in patients with cancer.

METHODS

For the in vivo experiment, mice received intraperitoneal injection of 5-fluorouracil (5-FU) at a dose of 75 mg/kg/day for 1, 3 or 5 days. Villus height and crypt depth of the small intestine, cell apoptosis and proliferation were then examined to determine the extent of CIMI. The expressions of Akt, p53, PUMA and p21 were evaluated both in vivo in mice models and in vitro in the IEC-6 and HCT116 cell lines.

RESULTS

After 5-FU therapy both the intestinal villus height (275.93 μm vs 164.52 μm, P < 0.001) and crypt depth (64.13 μm vs 42.48 μm, P < 0.001) were decreased. The apoptotic index was greatly increased from 0.32% to 15.84% (P < 0.001) and proliferation was suppressed (63.58% vs 39.15%, P < 0.001). Additionally, p53 expression was significantly increased in the intestinal crypt along with the expressions of PUMA and p21. Western blot showed that the administration of 5-FU induced p53/PUMA-mediated apoptosis and upregulated p21 expression to suppress cell proliferation.

CONCLUSION

Chemotherapy might mediate intestinal injury via p53/PUMA-mediated apoptotic signaling and the suppression of proliferation in response to p21.