Integrative Omics Analysis Revealed that Metabolic Intervention Combined with Metronomic Chemotherapy Selectively Kills Cancer Cells

Metronomic chemotherapy as a potential partner of immune checkpoint inhibitors for metastatic colorectal cancer treatment

The use of immune checkpoint inhibitors (ICIs) in clinical practice for the treatment of metastatic colorectal cancer (mCRC) is currently limited to patients with deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H), which comprise less than 5% of all mCRC cases. Combining ICIs with anti-angiogenic inhibitors, which modulate the tumor microenvironment, may reinforce and synergize the anti-tumor immune responses of ICIs. In mCRCs, combinations of pembrolizumab and lenvatinib have shown good efficacy in early phase trials. These results suggest the potential utility of immune modulators as partners in combination treatment with ICIs in immunologically cold microsatellite stable, as well as hot dMMR/MSI-H tumors. Unlike conventional pulsatile maximum tolerated dose chemotherapy, low-dose metronomic (LDM) chemotherapy recruits immune cells and normalizes vascular-immune crosstalk, similar to anti-angiogenic drugs. LDM chemotherapy mostly modulates the tumor stroma rather than directly killing tumor cells. Here, we review the mechanism of LDM chemotherapy in terms of immune modulation and its potential as a combination partner with ICIs for the treatment of patients with mCRC tumors, most of which are immunologically cold.

Comprehensive metabolomic profiling of nutrients in fish and shrimp

Although fish and shrimp are commonly consumed in daily life and recognized as nutrient-rich species, global profiling of the endogenous nutrients in these species is lacking. Here, we optimized the sample preparation and data acquisition methods of metabolomics to comprehensively characterize the nutrients in selected fish and shrimp species and compared them with those in beef, leading to the identification of 71 differentially expressed metabolites. Of these, docosahexaenoic acid, taurine, choline and (lyso)phosphatidylcholines were found to be abundant in the examined fish species, while several nonessential amino acids were rich in the analyzed shrimp samples. Subsequently, the biological functions of the metabolites rich in shrimp were queried. Intriguingly, the examined nutrients exemplified by proline can significantly mitigate the lipopolysaccharide (LPS)-stimulated inflammatory responses in BV2 cells and RAW264.7 cells. Collectively, our findings imply that the dietary intake of certain fish and shrimp species may benefit human health through alleviating inflammatory responses.

A diet-microbial metabolism feedforward loop modulates intestinal stem cell renewal in the stressed gut

Dietary patterns and psychosocial factors, ubiquitous part of modern lifestyle, critically shape the gut microbiota and human health. However, it remains obscure how dietary and psychosocial inputs coordinately modulate the gut microbiota and host impact. Here, we show that dietary raffinose metabolism to fructose couples stress-induced gut microbial remodeling to intestinal stem cells (ISC) renewal and epithelial homeostasis. Chow diet (CD) and purified diet (PD) confer distinct vulnerability to gut epithelial injury, microbial alternation and ISC dysfunction in chronically restrained mice. CD preferably enriches Lactobacillus reuteri, and its colonization is sufficient to rescue stress-triggered epithelial injury. Mechanistically, dietary raffinose sustains Lactobacillus reuteri growth, which in turn metabolizes raffinose to fructose and thereby constituting a feedforward metabolic loop favoring ISC maintenance during stress. Fructose augments and engages glycolysis to fuel ISC proliferation. Our data reveal a diet-stress interplay that dictates microbial metabolism-shaped ISC turnover and is exploitable for alleviating gut disorders.

A novel method to detect intracellular metabolite alterations in MCF-7 cells by doxorubicin induced cell death

BACKGROUND

Metabolic reprogramming within cancer cells has been recognized as a potential barrier to chemotherapy. Additionally, metabolic tumor heterogeneity is the one of factors behind discernible hallmarks such as drug resistance, relapse of the tumor and the formation of secondary tumors.

METHODS

In this paper, cell-based assays including PI/annexin V staining and immunoblot assay were performed to show the apoptotic cell death in MCF-7 cells treated with DOX. Further, MCF-7 cells were lysed in a hypotonic buffer and the whole cell lysate was purified by a novel and specifically designed metabolite (~ 100 to 1000 Da) fractionation system called vertical tube gel electrophoresis (VTGE). Further, purified intracellular metabolites were subjected to identification by LC-HRMS technique.

RESULTS

Cleaved PARP 1 in MCF-7 cells treated with DOX was observed in the present study. Concomitantly, data showed the absence of active caspase 3 in MCF-7 cells. Novel findings are to identify key intracellular metabolites assisted by VTGE system that include lipid (CDP-DG, phytosphingosine, dodecanamide), non-lipid (N-acetyl-D-glucosamine, N1-acetylspermidine and gamma-L-glutamyl-L-cysteine) and tripeptide metabolites in MCF-7 cells treated by DOX. Interestingly, we reported the first evidence of doxorubicinone, an aglycone form of DOX in MCF-7 cells that are potentially linked to the mechanism of cell death in MCF-7 cells.

CONCLUSION

This paper reported novel methods and processes that involve VTGE system based purification of hypotonically lysed novel intracellular metabolites of MCF-7 cells treated by DOX. Here, these identified intracellular metabolites corroborate to caspase 3 independent and mitochondria induced apoptotic cell death in MCF-7 cells. Finally, these findings validate a proof of concept on the applications of novel VTGE assisted purification and analysis of intracellular metabolites from various cell culture models.

Functional Metabolomics and Chemoproteomics Approaches Reveal Novel Metabolic Targets for Anticancer Therapy

Cancer cells exhibit different metabolic patterns compared to their normal counterparts. Although the reprogrammed metabolism has been indicated as strong biomarkers of cancer initiation and progression, increasing evidences suggest that metabolic alteration tuned by oncogenic drivers contributes to the occurrence and development of cancers rather than just being a hallmark of cancer. With this notion, targeting cancer metabolism holds promise as a novel anticancer strategy and is embracing its renaissance during the past two decades. Herein we have summarized the most recent developments in omics technology, including both metabolomics and proteomics, and how the combined use of these analytical tools significantly impacts this field by comprehensively and systematically recording the metabolic changes in cancer and hence reveals potential therapeutic targets that function by modulating the disrupted metabolic pathways.

Paeoniflorin modulates gut microbial production of indole-3-lactate and epithelial autophagy to alleviate colitis in mice

BACKGROUND

Total glucosides of peony (TGP), extracted from the root and rhizome of Paeonia lactiflora Pall, has well-confirmed immunomodulatory efficacy in the clinic. However, the mechanism and active ingredients remain largely unclear.

HYPOTHESIS/PURPOSE

Our previous study revealed a low systemic exposure but predominant gut distribution of TGP components. The aim of this study was to investigate involvement of the gut microbiota in the immunoregulatory effects and identify the active component.

METHODS

Mice received 3% DSS to establish a model of colitis. The treatment group received TGP or single paeoniflorin (PF) or albiflorin (AF). Body weight, colon length, inflammatory and histological changes were assessed. Gut microbiota structure was profiled by 16s rRNA sequencing. Antibiotic treatment and fecal transplantation were used to explore the involvement of gut microbiota. Metabolomic assay of host and microbial metabolites in colon was performed.

RESULTS

TGP improved colonic injury and gut microbial dysbiosis in colitis mice, and PF was responsible for the protective effects. Fecal microbiota transfer from TGP-treated mice conferred resilience to colitis, while antibiotic treatment abrogated the protective effects. Both TGP and PF decreased colonic indole-3-lactate (ILA), a microbial tryptophan metabolite. ILA was further identified as an inhibitor of epithelial autophagy and ILA supplementation compromised the benefits of TGP.

CONCLUSION

Our findings suggest that TGP acts in part through a gut microbiota-ILA-epithelial autophagy axis to alleviate colitis.

An improved detection and identification strategy for untargeted metabolomics based on UPLC-MS

Untargeted metabolomics provides a comprehensive investigation of metabolites and enables the discovery of biomarkers. Improvements in sample preparation, chromatographic separation and raw data processing procedure greatly enhance the metabolome coverage. In addition, database-dependent software identification is also essential, upon which enhances the identification confidence and benefits downstream biological analysis. Herein, we developed an improved detection and identification strategy for untargeted metabolomics based on UPLC-MS. In this work, sample preparation was optimized by considering chemical properties of different metabolites. Chromatographic separation was done by two different columns and MS detection was performed under positive and negative ion modes regarding to the different polarities of metabolites. According to the characteristics of the collected data, an improved identification and evaluation strategy was developed involving fragment simulation and MS/MS library search based on two commonly used databases, HMDB and METLIN. Such combination integrated information from different databases and was aimed to enhance identification confidence by considering the rationality of fragmentation, biological sources and functions comprehensively. In addition, decision tree analysis and lab-developed database were also introduced to assist the data processing and enhance the identification confidence. Finally, the feasibility of the developed strategy was validated by liver samples of obesity mice and controls. 238 metabolites were accurately detected, which was beneficial for the subsequent biomarker discovery and downstream pathway analysis. Therefore, the developed strategy remarkably facilitated the identification accuracy and the confirmation of metabolites in untargeted metabolomics.