Relationship between intestinal microorganisms and T lymphocytes in colorectal cancer

Impacts of pre-existing diabetes mellitus on colorectal cancer in a mice model

BACKGROUND

Although diabetes mellitus (DM) is regarded as a risk factor of colorectal cancer (CRC), the impacts of pre-existing DM on CRC without drug intervention remain unknown. The purpose of this study was to investigate and analyze the effects of diabetes mellitus (DM) on colorectal cancer (CRC). And, to further explore the influencing factors and the mechanisms of DM affects CRC progression.

METHODS

In this study, we investigated the effects of DM on CRC progression in a streptozotocin-induced DM mice model. Furthermore, we evaluated the change of T cells levels using flow cytometry and indirect immunofluorescence. We assessed the alternation of gut microbiome and the transcriptional response using 16s rRNA sequencing and RNA-seq.

RESULTS

Results showed that the mice survival time was significantly decreased in CRC complicated with DM group (DM-CRC), compared with only tumor bearing mice (CRC group). Furthermore, we found that DM could affect the immune response by changing the infiltration of CD4+ T cells, CD8+ T cells and mucosal-associated invariant T cell (MAIT) in the CRC progression. In addition, DM could induce gut microbiome dysbiosis and change the transcriptional response in CRC complicated with DM.

CONCLUSION

For the first time, the effects of DM on CRC were systematically characterized in a mice model. Our findings highlight the effects of pre-existing DM on CRC, and these findings should facilitate further studies in exploring and developing potentially targeted therapy for CRC in diabetic patients. Our results suggest that the effects induced by DM should be considered in the treatment for CRC complicated with DM patients.

Anti-Colorectal Cancer Effects of Inonotus hispidus (Bull.: Fr.) P. Karst. Spore Powder through Regulation of Gut Microbiota-Mediated JAK/STAT Signaling

Inonotus hispidus (Bull.: Fr.) P. Karst. spore powder (IHS) contains polyphenols and triterpenoids with pharmacological effects. Here, we analyzed its composition, and we investigated the effects of IHS on colorectal cancer (CRC) in B6/JGpt-Apc^em1Cin(min)/Gpt (Apc^Min/+) mice and its potential mechanisms by analyzing gut microbiota and serum metabolomics. The enzyme-linked immunosorbent assays and Western blotting were used to confirm the changes in the cytokine and protein levels associated with IHS administration. The IHS affected the abundance of gut microbiota and the level of L-arginine (L-Arg). Furthermore, the IHS influenced T cells in Apc^Min/+ mice by increasing the interleukin (IL)-2 and decreasing the IL-5, -6, and -10 levels, thus suppressing tumor development. Overall, IHS showed anti-CRC properties in Apc^Min/+ mice by affecting the gut microbiota and serum metabolites, which in turn affected the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling, and regulated the abundance of CD8⁺ T cells. These results provide experimental support for the potential future treatment of CRC with IHS.

Bacteria from Infectious Particles to Cell Based Anticancer Targeted Drug Delivery Systems

Bacterial ghosts (BGs) are empty cell envelopes of nonliving evacuated bacterial cells. They are free from their cytoplasmic contents; however, they sustain their cellular 3D morphology and antigenic structures, counting on bioadhesive properties. Lately, they have been tested as an advanced drug delivery system (DDS) for different materials like DNA, peptides, or drugs, either single components or combinations. Different studies have revealed that, BG DDS were paid the greatest attention in recent years. The current review explores the impact of BGs on the field of drug delivery and drug targeting. BGs have a varied area of applications, including vaccine and tumor therapy. Moreover, the use of BGs, their synthesis, their uniqueness as a delivery system and application principles in cancer are discussed. Furthermore, the safety issues of BGs and stability aspects of using ghost bacteria as delivery systems are discussed. Future perspective efforts that must be followed for this important system to continue to grow are important and promising.

Quxie Capsule Modulating Gut Microbiome and Its Association With T cell Regulation in Patients With Metastatic Colorectal Cancer: Result From a Randomized Controlled Clinical Trial

Aim:

Quxie capsule(QX), a TCM compound, had shown benefit on survival outcomes for metastatic colorectal cancer(mCRC) patients and could inhibit tumor growth through immune regulation. This study aimed to evaluate whether such effect is associated with gut microbiome modulation.

Method:

We conducted a randomized double-blinded placebo controlled clinical trial in Xiyuan Hospital, China Academy of Chinese Medical Sciences. All patients were randomly assigned into QX or placebo control group. Before and after 1-month interventions, we collected patients’ stool samples for microbiome analysis by 16s rRNA sequencing approaches, as well as blood samples to analyze T lymphocyte subsets by flow cytometry methods. Microbiome analysis among groups was done through bioinformation analysis platform. The study had been proved by the ethics committee of Xiyuan Hospital (2016XLA122-1) had been registered on Chinese Clinical Trial Registry (registration number: ChiCTR2000029599). All patients consented before enrollment.

Results:

We randomly assigned 40 patients and 34 were finally analyzed. Among them, 29% were female, with an average age of 63 years old, and 74% had liver or lung metastasis. Both CD4 T(TH) cell and CD8 T(TC) cell counts increased after QX treatment, while TH cells were significantly more in QX than in control group (737 vs 449, P = .024). Microbiome community analysis on Class level showed that the proportion of Actinobacteria declined in the control group, but significantly increased after QX treatments (0.83% vs 4.7%, P = .017). LEfSe analysis showed that after treatments, samples from QX group were highly related with Oscillibacter, Eubacterium, and Lachnospiraceae. RDA analysis showed that after QX interventions, stool samples and microbiome species had relevance with TC/TH cells counts but were not statistically significant. Heatmap analysis on Genus level revealed that after QX treatments, higher amounts of TH cells were significantly associated with less abundance of g_Bifidobacterium (coef. −0.76, P = .002), Collinsella (coef.−0.61, P = .02), Ruminiclostridium_9 (coef. −0.64, P = .01).

Conclusion:

QX capsule could enhance TH cells level among mCRC patients and increase the abundance of gut anticancer bacteria such as Actinobacteria as well as butyrate-producing bacteria such as Lachnospiraceae. These results indicated that QX capsule might have the property of dual effects of antitumor and immunity enhancement, both mediated by the microbiome.

The inhibitory effects of probiotics on colon cancer cells: in vitro and in vivo studies

Background

Colorectal cancer (CRC) is the most common gastrointestinal malignancy. And probiotics may have the function of preventing colon cancer. The aim of this study was to investigate the inhibitory effects of a probiotic mixture on colorectal cancer and its potential mechanisms.

Methods

The effects of the probiotic mixture on proliferation and metastasis of mouse colon cancer CT26 cells were assessed by probiotics and cells co-culture assay, Cell Counting Kit-8 assay, colony formation assay, wound-healing assay, as well as migration and invasion assays. And CT26 cells were also transplanted into BALB/c mice to construct transplanted tumor animal model. The mice were randomly divided into two groups, control group and probiotic mixture intragastric administration group, after injection 21 days the tumor size and infiltration of immune cells in the tumor or spleen tissues were analyzed by hematoxylin and eosin (HE) and immunohistochemistry (IHC) staining.

Results

The probiotic mixture significantly inhibited the proliferation, invasion, and migration ability of CT26 cells compare to the control cells (P<0.05). In the animal experiments, the tumor volume of mice that had been fed the probiotic mixture was significantly smaller than that of the control group (P<0.05). Compared with control mice, more apoptotic cells and infiltration of immune cells were showed in the tumor tissues of the mice treated with the probiotic mixture, and an increased number of CD8+ cells in the tumor and spleen tissues but no significant change in tissues.

Conclusions

These results suggested that the probiotic mixture could inhibit the growth of CT26 tumors and induce an immune response in vivo. The probiotic mixture also inhibited the invasion, migration, and proliferation ability of CT26 cells in vitro.

Progress in Research on Colorectal Cancer-Related Microorganisms and Metabolites

Intestinal flora is an important component in the human body, which have been reported to be involved in the occurrence and development of colorectal cancer (CRC). Indeed, changes in the intestinal flora in CRC patients compared to those in control subjects have been reported. Several bacterial species have been shown to exhibit the pro-inflammatory and pro-carcinogenic properties, which could consequently have an impact on colorectal carcinogenesis. In this review, we summarize the current knowledge on the potential links between the intestinal microbiota and CRC. We illustrated the mechanisms by which intestinal flora imbalance affects CRC, mainly focusing on inflammation, microbial metabolites, and specific bacteria species. In addition, we discuss how a diet exhibits a strong impact on microbial composition and provides risks for developing CRC. Finally, we describe the potential future directions that are based on intestinal microbiota manipulation for CRC diagnosis and treatment.

The effect of acupuncture on tumor growth and gut microbiota in mice inoculated with osteosarcoma cells

Background

Cancer is a complex systemic disease. As a key component of traditional Chinese medicine, acupuncture is a clinically proven medical treatment for many diseases, and it also has preventative effects as it balances the body, allowing it to self-regulate. For cancer patients, acupuncture is widely used as complementary therapy to boost the immune system and reduce the side effects of radiotherapy and chemotherapy. However, few studies have determined how acupuncture against cancer, especially in regulating the intestinal flora of the tumor-burdened mice.

Methods

We treated osteosarcoma tumor-burdened mice by using needling on different acupoints and acupoints combination, thereafter determined the effects of acupuncture on tumor growth by using imaging technology in vitro. In addition, intestinal bacteria were analyzed for further understanding the holistic and systemic treatment effects of acupuncture in osteosarcoma tumor-burdened mice.

Results

Acupuncture treatment can delay tumor growth and changes of intestinal bacteria in osteosarcoma tumor-burdened mice. In detail, the loss of body weight and the development of tumor volume of mice have been postposed by needling specific acupoints. In addition, acupuncture treatment has delayed the changes of the relative abundance of Bacteroidetes, Firmicutes and Candidatus Saccharibacteria at the phylum level. Moreover, the relative abundance of many bacteria (e.g., Catabacter, Acetatifactor and Aestuariispira) has been regulated by using acupuncture treatment, and the trend of structural changes of these bacteria at the genus level has also been postposed compared to that of the tumor-burdened mice model group.

Conclusion

Our results suggest that acupuncture may provide a systemic treatment for cancer. Our findings encourage new and extensive research into the effects of acupuncture on changes of the intestinal microbiome associated with the development of cancer.

Tea polyphenols and their chemopreventive and therapeutic effects on colorectal cancer

Colorectal cancer (CRC), a multifactorial disease, is usually induced and developed through complex mechanisms, including impact of diet and lifestyle, genomic abnormalities, change of signaling pathways, inflammatory response, oxidation stress, dysbiosis, and so on. As natural polyphenolic phytochemicals that exist primarily in tea, tea polyphenols (TPs) have been shown to have many clinical applications, especially as anticancer agents. Most animal studies and epidemiological studies have demonstrated that TPs can prevent and treat CRC. TPs can inhibit the growth and metastasis of CRC by exerting the anti-inflammatory, anti-oxidative or pro-oxidative, and pro-apoptotic effects, which are achieved by modulations at multiple levels. Many experiments have demonstrated that TPs can modulate several signaling pathways in cancer cells, including the mitogen-activated protein kinase pathway, phosphatidylinositol-3 kinase/Akt pathway, Wnt/β-catenin pathway, and 67 kDa laminin receptor pathway, to inhibit proliferation and promote cell apoptosis. In addition, novel studies have also suggested that TPs can prevent the growth and metastasis of CRC by modulating the composition of gut microbiota to improve immune system and decrease inflammatory responses. Molecular pathological epidemiology, a novel multidisciplinary investigation, has made great progress on CRC, and the further molecular pathological epidemiology research should be developed in the field of TPs and CRC. This review summarizes the existing in vitro and in vivo animal and human studies and potential mechanisms to examine the effects of tea polyphenols on CRC.