Chitooligosaccharides promote radiosensitivity in colon cancer line SW480

Ovarian microenvironment: challenges and opportunities in protecting against chemotherapy-associated ovarian damage

BACKGROUND

Chemotherapy-associated ovarian damage (CAOD) is one of the most feared short- and long-term side effects of anticancer treatment in premenopausal women. Accumulating detailed data show that different chemotherapy regimens can lead to disturbance of ovarian hormone levels, reduced or lost fertility, and an increased risk of early menopause. Previous studies have often focused on the direct effects of chemotherapeutic drugs on ovarian follicles, such as direct DNA damage-mediated apoptotic death and primordial follicle burnout. Emerging evidence has revealed an imbalance in the ovarian microenvironment during chemotherapy. The ovarian microenvironment provides nutritional support and transportation of signals that stimulate the growth and development of follicles, ovulation, and corpus luteum formation. The close interaction between the ovarian microenvironment and follicles can determine ovarian function. Therefore, designing novel and precise strategies to manipulate the ovarian microenvironment may be a new strategy to protect ovarian function during chemotherapy.

OBJECTIVE AND RATIONALE

This review details the changes that occur in the ovarian microenvironment during chemotherapy and emphasizes the importance of developing new therapeutics that protect ovarian function by targeting the ovarian microenvironment during chemotherapy.

SEARCH METHODS

A comprehensive review of the literature was performed by searching PubMed up to April 2024. Search terms included 'ovarian microenvironment' (ovarian extracellular matrix, ovarian stromal cells, ovarian interstitial, ovarian blood vessels, ovarian lymphatic vessels, ovarian macrophages, ovarian lymphocytes, ovarian immune cytokines, ovarian oxidative stress, ovarian reactive oxygen species, ovarian senescence cells, ovarian senescence-associated secretory phenotypes, ovarian oogonial stem cells, ovarian stem cells), terms related to ovarian function (reproductive health, fertility, infertility, fecundity, ovarian reserve, ovarian function, menopause, decreased ovarian reserve, premature ovarian insufficiency/failure), and terms related to chemotherapy (cyclophosphamide, lfosfamide, chlormethine, chlorambucil, busulfan, melphalan, procarbazine, cisplatin, doxorubicin, carboplatin, taxane, paclitaxel, docetaxel, 5-fluorouraci, vincristine, methotrexate, dactinomycin, bleomycin, mercaptopurine).

OUTCOMES

The ovarian microenvironment shows great changes during chemotherapy, inducing extracellular matrix deposition and stromal fibrosis, angiogenesis disorders, immune microenvironment disturbance, oxidative stress imbalances, ovarian stem cell exhaustion, and cell senescence, thereby lowering the quantity and quality of ovarian follicles. Several methods targeting the ovarian microenvironment have been adopted to prevent and treat CAOD, such as stem cell therapy and the use of free radical scavengers, senolytherapies, immunomodulators, and proangiogenic factors.

WIDER IMPLICATIONS

Ovarian function is determined by its 'seeds' (follicles) and 'soil' (ovarian microenvironment). The ovarian microenvironment has been reported to play a vital role in CAOD and targeting the ovarian microenvironment may present potential therapeutic approaches for CAOD. However, the relation between the ovarian microenvironment, its regulatory networks, and CAOD needs to be further studied. A better understanding of these issues could be helpful in explaining the pathogenesis of CAOD and creating innovative strategies for counteracting the effects exerted on ovarian function. Our aim is that this narrative review of CAOD will stimulate more research in this important field.

REGISTRATION NUMBER

Not applicable.

Chitinase-Assisted Bioconversion of Chitinous Waste for Development of Value-Added Chito-Oligosaccharides Products

Chito-oligosaccharides (COSs) are the partially hydrolyzed products of chitin, which is abundant in the shells of crustaceans, the cuticles of insects, and the cell walls of fungi. These oligosaccharides have received immense interest in the last few decades due to their highly promising bioactivities, such as their anti-microbial, anti-tumor, and anti-inflammatory properties. Regarding environmental concerns, COSs are obtained by enzymatic hydrolysis by chitinase under milder conditions compared to the typical chemical degradation. This review provides updated information about research on new chitinase derived from various sources, including bacteria, fungi, plants, and animals, employed for the efficient production of COSs. The route to industrialization of these chitinases and COS products is also described.

A Randomized Placebo-Controlled Phase 2 Study of Gemcitabine and Capecitabine with or without T-ChOS as Adjuvant Therapy in Patients with Resected Pancreatic Cancer (CHIPAC)

The antitumor activity of chitooligosaccharides has been suggested. This phase 2 trial evaluated the efficacy and safety of T-ChOS™, in addition to adjuvant chemotherapy, in patients after resection of pancreatic ductal adenocarcinoma (PDAC). In this single-center, randomized, double-blind, placebo-controlled trial using patients ≥18 years of age after complete macroscopic resection for PDAC, patients were randomly assigned (1:1) to either a continuous oral T-ChOS group or a placebo group, in combination with gemcitabine (GEM) and oral capecitabine (CAP), for a maximum of six cycles. The primary endpoint was disease-free survival (DFS). Recruitment was stopped prematurely in July 2018, with 21 of planned 180 patients included, due to poor accrual and because modified FOLFIRINOX replaced GEM/CAP for the target population. Nine patients received T-ChOS and twelve received the placebo. The median DFS was 10.8 months (95% CI 5.9–15.7) for the T-ChOS arm and 8.4 months (95% CI 0–21.5) in the placebo arm. Overall, seven patients (78%) in the T-ChOS arm and eight patients (67%) in the placebo arm experienced at least one grade 3–4 treatment-related adverse event, most frequently neutropenia. Altogether, the addition of T-ChOS to chemotherapy in patients after resection of PDAC seems safe. However, the clinical benefit cannot be assessed due to the premature cessation of the trial.

A comparative study of the effects of crab derived exosomes and doxorubicin in 2 & 3-dimensional in vivo models of breast cancer

INTRODUCTION

Using tissue engineering and modifying the tumor microenvironment, three-dimensional (3D) in vitro and in vivo cancer modeling can be performed with appropriate similarity to native. Exosomes derived from different sources have recently been used in cancer studies due to their anticancer effects. In this study, the effect of crab derived exosomes in 2 & 3-dimensional (2& 3D) in vivo models of breast cancer (BC) were investigated and compared with the doxorubicin (DOX).

METHODS

2D and 3D models of BC were induced using the chitosan/β-glycerol phosphate hydrogel (Ch/β-GP) and 1 × 10⁶ 4T1 cells in the female mice aged 6-8 weeks. 1 mg/ml exosome and 5 mg/kg DOX were injected by intratumoral (IT), intravenous (IV), and intraperitoneal (IP) methods into mice on day 9, 13, and 17 with and without hydrogel as a drug delivery system. After 21 days, the mice were sacrificed, and the tissues (lung, liver, and tumor) were removed. The weight and size of the tumor were measured. Real-time PCR assessed changes of VEGF, Bcl2, and P53 genes expression levels. Nitric oxide (NO) secretion from the cancer 3D model was evaluated by Griess assay.

RESULTS AND CONCLUSION

Based on the results, the size and weight of tumors in treated groups with exosomes and DOX were reduced significantly (P ≤ 0.001, P ≤ 0.002, P ≤ 0.02) in 2D and 3D models. Changes in VEGF, Bcl2 and P53 gene expression levels were less in the 3D model than in the 2D model. Drug delivery with hydrogel increased tumor inhibition compared to drug injection without hydrogel. Decreased NO secretion was observed in all treatment groups compared to the control group (untreated). Crab exosomes showed anti cancer effects on 2&3D models of BC. 3D model of BC showed greater drug resistance than the 2D model after treating with crab derived exosomes and DOX. 3D model of BC mimics native tumor better than 2D and can be used in cancer studies and for drug screening with greater confidence than 2D model. Also, the use of slow release drug delivery system reduced drug resistance in both models.

Chitooligosaccharides Prevents the Development of Colitis-Associated Colorectal Cancer by Modulating the Intestinal Microbiota and Mycobiota

Gut microbes play a crucial role in the development of colorectal cancer. Chitooligosaccharides (COS), are oligomer that are depolymerized from chitosan and possess a wide range of biological activities. In this study, the effects of COS on colorectal cancer (CRC) development were evaluated using azoxymethane and dextran sulfate sodium (AOM/DSS) induced mouse model of CRC (CACM). In the COS-treated CRC group (CMCOS), COS protected mice from CRC by decreasing the disease activity index, tumor incidences and multiplicity, and the mRNA levels of COX-2, IL-6, TNF-α, IL-1β, IL-10, and IKK-β mRNA in colonic epithelial cells. The results of a cage-exchanged experiment, in which mice from the CACMe and CMCOSe treatments exchanged cages every day to interact with microbes, showed that gut microbes play an important role in preventing CAC by COS. The abundances of fecal bacteria (total bacteria, Lactobacillus, Enterococcus, Fusobacterium nucleatum and butyrate-producing bacteria) were detected by qPCR on the 0th, 1st, 3rd, 6th, 9th, and 10th weekends. Furthermore, microbiota and mycobiota were analyzed by high-throughput sequencing on an Illumina MiSeq PE300 system. COS protected mice from CRC by reversing the imbalance of bacteria and fungi, especially by reducing the abundance of Escherichia-Shigella, Enterococcus, and Turicibacter, and increasing the levels of Akkermansia, butyrate-producing bacteria and Cladosporium.