Cancer continues to pose a significant global health challenge, with gastrointestinal (GI) cancers among the most prevalent and deadly forms. These cancers often lead to high mortality rates and demand the use of potent cytotoxic chemotherapeutics. For example, 5-fluorouracil (5-FU) forms the backbone of chemotherapy regimens for various GI cancers, including colorectal cancer. While these chemotherapeutics efficiently kill cancer cells, they frequently cause off-target effects such as chemotherapy-induced mucositis (CIM), characterized by debilitating symptoms like pain, nausea, and diarrhoea, necessitating medical intervention. In this study, we elucidated the potential of melatonin and misoprostol to reduce 5-FU-induced small intestinal mucositis. Morphological and cellular changes in the jejunum, along with colonic faecal water content were quantified in rats as markers for CIM. Additionally, the effects of melatonin were investigated in vitro on 5-FU treated murine intestinal organoids. The results showed that melatonin prevented villus atrophy in the rat jejunal mucosa and upheld cell viability in murine intestinal organoids. In contrast, misoprostol alone or in combination with melatonin did not significantly affect CIM caused by 5-FU. These in vivo and in vitro experiments provided promising insights that melatonin may be used as a preventive and/or adjuvant combination therapy to prevent and reduce CIM, holding the potential to enhance cancer treatment outcomes and improve patient quality-of-life.

Chemotherapy-induced mucositis, characterized by diarrhoea and villous atrophy, is a severe side effect contributing to reduced quality of life and premature death in cancer patients treated with cytostatics. Despite its high incidence, there is no effective supportive therapy available. The main objective of this study was to determine if the anti-inflammatory drugs anakinra and/or dexamethasone-which have different mechanisms-of-action-might be used to effectively treat idarubicin-induced mucositis in rats. Mucositis was induced through a single injection with 2 mg/kg idarubicin (with saline as control), followed by daily treatments of anakinra (100 mg/kg/day), dexamethasone (10 mg/kg/day) or both for 3 days. After 72 h, jejunal tissue was collected for morphological, apoptotic and proliferative analyses, and colonic faecal water content and body weight change were determined. The diarrhoea that was induced by idarubicin (from 63.5% to 78.6% water content in faeces) was completely reversed by anakinra alone, and the jejunal villus height reduction by 36% was prevented by a combination of anakinra and dexamethasone. Dexamethasone reduced apoptosis in the jejunal crypts, both alone and in combination with anakinra. These positive effects encouraged further investigations into the use of anakinra and dexamethasone as supportive therapies for chemotherapy-induced intestinal mucositis and diarrhoea.

Ad libitum feeding of experimental animals is preferred because of medical relevance together with technical and practical considerations. In addition, ethical committees may require ad libitum feeding. However, feeding affects the metabolism so ad libitum feeding may mask the effects of drugs on tissues directly involved in the digestion process (e.g., jejunum and liver). Despite this effect, principal component analysis has the potential of identifying metabolic traits that are statistically independent (orthogonal) to ad libitum feeding. Consequently, we used principal component analysis to discover the metabolic effects of doxorubicin independent of ad libitum feeding. First, we analyzed the lipidome of the jejunum and the liver of rats treated with vehicle or doxorubicin. Subsequently, we performed principal component analysis. We could identify a principal component associated to the hydrolysis of lipids during digestion and a group of lipids that were orthogonal. These lipids in the jejunum increased with the treatment time and presented a polyunsaturated fatty acid as common structural trait. This characteristic suggests that doxorubicin increases polyunsaturated fatty acids. This behavior agrees with our previous in vitro results and suggests that doxorubicin sensitized the jejunum to ferroptosis, which may partially explain the toxicity of doxorubicin in the intestines.

Chemotherapy-induced intestinal mucositis is a severe side effect contributing to reduced quality of life and premature death in cancer patients. Despite a high incidence, a thorough mechanistic understanding of its pathophysiology and effective supportive therapies are lacking. The main objective of this rat study was to determine how 10 mg/kg doxorubicin, a common chemotherapeutic, affected jejunal function and morphology over time (6, 24, 72, or 168 h). The secondary objective was to determine if the type of dosing administration (intraperitoneal or intravenous) affected the severity of mucositis or plasma exposure of the doxorubicin. Morphology, proliferation and apoptosis, and jejunal permeability of mannitol were examined using histology, immunohistochemistry, and single-pass intestinal perfusion, respectively. Villus height was reduced by 40% after 72 h, preceded at 24 h by a 75% decrease in proliferation and a sixfold increase in apoptosis. Villus height recovered completely after 168 h. Mucosal permeability of mannitol decreased after 6, 24, and 168 h. There were no differences in intestinal injury or plasma exposure after intraperitoneal or intravenous doxorubicin dosing. This study provides an insight into the progression of chemotherapy-induced intestinal mucositis and associated cellular mucosal processes. Knowledge from this in vivo rat model can facilitate development of preventive and supportive therapies for cancer patients.

Introduction Hepatocellular carcinoma (HCC) is a common cause of cancer-related death, often detected in the intermediate stage. The standard of care for intermediate-stage HCC is transarterial chemoembolisation (TACE), where idarubicin (IDA) is a promising drug. Despite the fact that TACE has been used for several decades, treatment success is unpredictable. This clinical trial has been designed believing that further improvement might be achieved by increasing the understanding of interactions between local pharmacology, tumour targeting, HCC pathophysiology, metabolomics and molecular mechanisms of drug resistance. Methods and analysis The study population of this single-centre clinical trial consists of adults with intermediate-stage HCC. Each tumour site will receive TACE with two different IDA doses, 10 and 15 mg, on separate occasions. Before and after each patient’s first TACE blood samples, tissue and liquid biopsies, and positron emission tomography (PET)/MRI will be performed. Blood samples will be used for pharmacokinetics (PK) and liver function evaluation. Tissue biopsies will be used for histopathology analyses, and culturing of primary organoids of tumour and non-tumour tissue to measure cell viability, drug response, multiomics and gene expression. Multiomics analyses will also be performed on liquid biopsies. PET/MRI will be used to evaluate tumour viability and liver metabolism. The two doses of IDA will be compared regarding PK, antitumour effects and safety. Imaging, molecular biology and multiomics data will be used to identify HCC phenotypes and their relation to drug uptake and metabolism, treatment response and survival. Ethics and dissemination Participants give informed consent. Personal data are deidentified. A patient will be withdrawn from the study if considered medically necessary, or if it is the wish of the patient. The study has been approved by the Swedish Ethical Review Authority (Dnr. 2021-01928) and by the Medical Product Agency, Uppsala, Sweden. Trial registration number EudraCT number: 2021-001257-31.

Chemotherapy-induced mucositis is characterized by diarrhoea and villous atrophy. However, it is not well-understood why diarrhoea arises, why it only occurs with some chemotherapeutics and how it is related to villus atrophy. The objectives in this study were to determine (i) the relationship between chemotherapy-induced diarrhoea and villus atrophy and to (ii) establish and validate a rat diarrhoea model with clinically relevant endpoints. Male Wistar Han IGS rats were treated with saline, doxorubicin, idarubicin, methotrexate, 5-fluorouracil, irinotecan or 5-fluorouracil+irinotecan. After 72 h, jejunal tissue was taken for morphological, apoptotic and proliferative analyses, and faecal water content and change in body weight were determined. All treatments except methotrexate caused a similar reduction (≈42%) in villus height, but none of them altered mucosal crypt cell proliferation or apoptosis. Doxorubicin, idarubicin, irinotecan and 5-fluorouracil+irinotecan caused body weight reduction, but only irinotecan and idarubicin caused diarrhoea. No direct correlation between diarrhoea and villus height or body weight loss was observed. Therefore, studies of the mechanisms for chemotherapy-induced diarrhoea should focus on functional factors. Finally, the irinotecan and idarubicin diarrhoea models established in this study will be useful in developing supportive treatments of this common and serious adverse effect in patients undergoing chemotherapy.

Chemotherapy causes intestinal mucositis, which includes villous atrophy and altered mucosal barrier function. However, there is an uncertainty regarding how the reduced small-intestinal surface area affects the mucosal permeability of the small marker probe mannitol (MW 188), and how the mucosa responds to luminal irritants after chemotherapy. The aims in this study were to determine (i) the relationship between chemotherapy-induced villus atrophy and the intestinal permeability of mannitol and (ii) how the mucosa regulate this permeability in response to luminal ethanol and sodium dodecyl sulfate (SDS). This was investigated by treating rats with a single intraperitoneal dose of doxorubicin, irinotecan, or 5-fluorouracil. After 72 h, jejunum was single-pass perfused and mannitol permeability determined at baseline and after 15 min luminal exposure to 15% ethanol or 5 mg/mL SDS. Tissue samples for morphological analyses were sampled from the perfused segment. All three chemotherapeutics caused a similar 30% reduction in villus length. Mannitol permeability increased with irinotecan (1.3-fold) and 5-fluorouracil (2.5-fold) and was reduced with doxorubicin (0.5-fold), suggesting that it is not epithelial surface area alone that regulates intestinal permeability to mannitol. There was no additional increase in mannitol permeability induced by luminal ethanol or SDS in the chemotherapy-treated rats compared to controls, which may be related to the relatively high basal permeability of mannitol compared to other common low-permeability probes. We therefore suggest that future studies should focus on elucidating the complex interplay between chemotherapy in combination with luminal irritants on the intestinal permeability of other probes.

Metabolic and personalized interventions in cancer treatment require a better under-standing of the relationship between the induction of cell death and metabolism. Consequently, we treated three primary liver cancer cell lines with two anthracyclins (doxorubicin and idarubin) and studied the changes of the lipidome. We found that both anthracyclins in the three cell lines increased the levels of polyunsaturated fatty acids (PUFAs) and alkylacylglycerophosphoethano-lamines (etherPEs) with PUFAs. As PUFAs and alkylacylglycerophospholipids with PUFAs are fundamental in lipid peroxidation during ferroptotic cell death, our results suggests supplementa-tion with PUFAs and/or etherPEs with PUFAs as a potential general adjuvant of anthracyclins. In contrast, neither the markers of de novo lipogenesis nor cholesterol lipids presented the same trend in all cell lines and treatments. In agreement with previous research, this suggests that modulation of the metabolism of cholesterol could be considered a specific adjuvant of anthracyclins depend-ing on the type of tumor and the individual. Finally, we discuss the changes in the lipidome in re-lation to the endoplasmic reticulum stress and the sensitivity to anthracyclins of the different cells. In conclusion, our results suggest that the modulation of different lipid metabolic pathways may be considered for generalized and personalized metabochemotherapies.

Metabolic and personalized interventions in cancer treatment require a better understanding of the relationship between the induction of cell death and metabolism. Consequently, we treated three primary liver cancer cell lines with two anthracyclins (doxorubicin and idarubin) and studied the changes in the lipidome. We found that both anthracyclins in the three cell lines increased the levels of polyunsaturated fatty acids (PUFAs) and alkylacylglycerophosphoethanolamines (etherPEs) with PUFAs. As PUFAs and alkylacylglycerophospholipids with PUFAs are fundamental in lipid peroxidation during ferroptotic cell death, our results suggest supplementation with PUFAs and/or etherPEs with PUFAs as a potential general adjuvant of anthracyclins. In contrast, neither the markers of de novo lipogenesis nor cholesterol lipids presented the same trend in all cell lines and treatments. In agreement with previous research, this suggests that modulation of the metabolism of cholesterol could be considered a specific adjuvant of anthracyclins depending on the type of tumor and the individual. Finally, in agreement with previous research, we found a relationship across the different cell types between: (i) the change in endoplasmic reticulum (ER) stress, and (ii) the imbalance between PUFAs and cholesterol and saturated lipids. In the light of previous research, this imbalance partially explains the sensitivity to anthracyclins of the different cells. In conclusion, our results suggest that the modulation of different lipid metabolic pathways may be considered for generalized and personalized metabochemotherapies.

Cytostatic effects of doxorubicin in clinically applied doses are often inadequate and limited by systemic toxicity. The main objective of this in vitro study was to determine the anti-tumoral effect (IC50) and intracellular accumulation of free and liposomal doxorubicin (DOX) in four human cancer cell lines (HepG2, Huh7, SNU449 and MCF7). The results of this study showed a correlation between longer DOX exposure time and lower IC50 values, which can be attributed to an increased cellular uptake and intracellular exposure of DOX, ultimately leading to cell death. We found that the total intracellular concentrations of DOX were a median value of 230 times higher than the exposure concentrations after exposure to free DOX. The intracellular uptake of DOX from solution was at least 10 times higher than from liposomal formulation. A physiologically based pharmacokinetic model was developed to translate these novel quantitative findings to a clinical context and to simulate clinically relevant drug concentration–time curves. This showed that a liver tumor resembling the liver cancer cell line SNU449, the most resistant cell line in this study, would not reach therapeutic exposure at a standard clinical parenteral dose of doxorubicin (50 mg/m2), which is serious limitation for this drug. This study emphasizes the importance of in-vitro to in-vivo translations in the assessment of clinical consequence of experimental findings.