Drug-induced gene expression profile changes in relation to intestinal toxicity: State-of-the-art and new approaches

TheMarker: a comprehensive database of therapeutic biomarkers

Distinct from the traditional diagnostic/prognostic biomarker (adopted as the indicator of disease state/process), the therapeutic biomarker (ThMAR) has emerged to be very crucial in the clinical development and clinical practice of all therapies. There are five types of ThMAR that have been found to play indispensable roles in various stages of drug discovery, such as: Pharmacodynamic Biomarker essential for guaranteeing the pharmacological effects of a therapy, Safety Biomarker critical for assessing the extent or likelihood of therapy-induced toxicity, Monitoring Biomarker indispensable for guiding clinical management by serially measuring patients' status, Predictive Biomarker crucial for maximizing the clinical outcome of a therapy for specific individuals, and Surrogate Endpoint fundamental for accelerating the approval of a therapy. However, these data of ThMARs has not been comprehensively described by any of the existing databases. Herein, a database, named 'TheMarker', was therefore constructed to (a) systematically offer all five types of ThMAR used at different stages of drug development, (b) comprehensively describe ThMAR information for the largest number of drugs among available databases, (c) extensively cover the widest disease classes by not just focusing on anticancer therapies. These data in TheMarker are expected to have great implication and significant impact on drug discovery and clinical practice, and it is freely accessible without any login requirement at: https://idrblab.org/themarker.

Zinc and L-carnitine combination with or without methotrexate prevents intestinal toxicity during arthritis treatment via Nrf2/Sirt1/Foxo3 pathways: an In vivo and molecular docking approach

Methotrexate (MTX) is an antifolate that is inescapable and widely used to treat autoimmune diseases and is the gold standard medicine for the arthritic condition. Despite its importance, it is more prone to gastrointestinal toxicity, which is most common in arthritis patients during MTX treatment. Combination therapies are required to ensure MTX's antiarthritic activity while providing gastrointestinal protection. Zinc (Zn) and L-carnitine (Lc) are well-known potent antioxidants and anti-inflammatory supplements with promising results in pre-clinical studies. Arthritis was induced in Wistar rat's ankles with Freund's adjuvant and treated with either MTX (2.5 mg/kg b.w per week for two weeks) or Zn (18 mg/kg b.w. per day) Lc (200 mg/kg b.w. per day) individually or in combination (MTX + Zn Lc). The antiarthritic effects were evaluated by body weight, paw volume, ankle tissue, and joint histopathology. At the same time, anti-toxicity/gastrointestinal protective activity was examined by tissue oxidative stress markers, antioxidants, mitochondrial function, inflammatory mediators, and antioxidant signaling proteins and their binding mechanism. Repercussions of MTX intoxication induced upregulation of oxidative stress markers, antioxidant depletion, ATP depletion, decreased expression of Nrf2/Sirt1/Foxo3, and the overexpression of inflammatory mediators attenuated by co-treatment with Zn Lc. Zn Lc markedly mitigated MTX-instigated intestinal injury by activating antioxidant signaling mechanisms Nrf2/Sirt1/Foxo3 signaling and tissue architectural anomalies and exhibited an enhanced antiarthritic effect. In conclusion, we report that Zn Lc and MTX combination could presumably protect the intestine from low-dose MTX which managed arthritis but induced severe intestinal damage with increased inflammation and downregulated Nrf2/Sirt1/Foxo3 pathway.

Cancer chemotherapy and beyond: Current status, drug candidates, associated risks and progress in targeted therapeutics

Cancer is an abnormal state of cells where they undergo uncontrolled proliferation and produce aggressive malignancies that causes millions of deaths every year. With the new understanding of the molecular mechanism(s) of disease progression, our knowledge about the disease is snowballing, leading to the evolution of many new therapeutic regimes and their successive trials. In the past few decades, various combinations of therapies have been proposed and are presently employed in the treatment of diverse cancers. Targeted drug therapy, immunotherapy, and personalized medicines are now largely being employed, which were not common a few years back. The field of cancer discoveries and therapeutics are evolving fast as cancer type-specific biomarkers are progressively being identified and several types of cancers are nowadays undergoing systematic therapies, extending patients' disease-free survival thereafter. Although growing evidence shows that a systematic and targeted approach could be the future of cancer medicine, chemotherapy remains a largely opted therapeutic option despite its known side effects on the patient's physical and psychological health. Chemotherapeutic agents/pharmaceuticals served a great purpose over the past few decades and have remained the frontline choice for advanced-stage malignancies where surgery and/or radiation therapy cannot be prescribed due to specific reasons. The present report succinctly reviews the existing and contemporary advancements in chemotherapy and assesses the status of the enrolled drugs/pharmaceuticals; it also comprehensively discusses the emerging role of specific/targeted therapeutic strategies that are presently being employed to achieve better clinical success/survival rate in cancer patients.

Gene expression responses reflecting 5-FU-induced toxicity: Comparison between patient colon tissue and 3D human colon organoids

Capecitabine is a chemotherapeutic drug that is widely used as a monotherapy option in advanced cancer patients. After administration, it is converted into its active metabolite 5-fluorouracil (5-FU), a cytotoxic compound that may also induce adverse side effects in the gastrointestinal (GI) tract. Although these side effects can interfere with the continuation of the chemotherapy, diagnostic tools to detect early onset and prevention strategies are not available. In this explorative case study, we aim to identify differentially expressed genes (DEGs) that provide insight into the molecular mechanisms of toxicity induced by 5-FU in healthy colon tissue of breast cancer patients receiving capecitabine. Gene expression responses observed in patients were compared with those established in an in vitro model of healthy colon organoids. Colon biopsies from two patients with advanced breast cancer were collected before and after the treatment with capecitabine and used for RNA sequencing to determine transcriptomic responses. Differential expression analysis resulted in 31 affected genes, showing that the most affected pathways were transport of small molecules, cellular responses to stress, folate metabolism, NF-kB signalling pathway and immune system responses. The most biologically relevant genes were haemoglobin subunits encoding genes, involved in several processes; ATP12A, SLC26A3 and AQP8, involved in the transport of ions and water; TRIM31, a regulator of NF-kB signalling pathway; MST1P2 and MST1L, stimulators of macrophages. Comparison of human in vitro and in vivo responses showed that the gene expression of TRIM31 was similarly altered in the colon organoids exposed to 5-FU. Therefore, this gene constitutes a potential biomarker of colon toxicity that might be used in future in vitro drug safety design and screening.

Organoid-derived intestinal epithelial cells are a suitable model for preclinical toxicology and pharmacokinetic studies

Intestinal organoids are physiologically relevant tools used for cellular models. However, the suitability of organoids to examine biological functions over existing established cell lines lacks sufficient evidence. Cytochrome P450 3A4 (CYP3A4) induction by pregnane X receptor ligands, glucose uptake via sodium/glucose cotransporter 1, and microsomal triglyceride transfer protein-dependent ApoB-48 secretion, which are critical for human intestinal metabolism, were observed in organoid-derived two-dimensional cells but little in Caco-2 cells. CYP3A4 induction evaluation involved a simplified method of establishing organoids that constitutively expressed a reporter gene. Compound screening identified several anticancer drugs with selective activities toward Caco-2 cells, highlighting their characteristics as cancer cells. Another compound screening revealed a decline in N-(4-hydroxyphenyl)retinamide cytotoxicity upon rifampicin treatment in organoid-derived cells, under CYP3A4-induced conditions. This study shows that organoid-derived intestinal epithelial cells (IECs) possess similar physiological properties as intestinal epithelium and can serve as tools for enhancing the prediction of biological activity in humans.

•

Comparison of mRNA expression between organoid-derived intestinal epithelial cells (IECs) and Caco-2 cells

•

Evaluation of CYP3A4, SGLT1, and MTP protein function in organoid-derived IECs

•

Identification of anti-cancer drugs as selective cytotoxicity against Caco-2 cells

•

Reduction of N-(4-hydroxyphenyl)retinamide (4-HPR) cytotoxicity by rifampicin in organoid-derived IECs

CETSA interaction proteomics define specific RNA-modification pathways as key components of fluorouracil-based cancer drug cytotoxicity

The optimal use of many cancer drugs is hampered by a lack of detailed understanding of their mechanism of action (MoA). Here, we apply a high-resolution implementation of the proteome-wide cellular thermal shift assay (CETSA) to follow protein interaction changes induced by the antimetabolite 5-fluorouracil (5-FU) and related nucleosides. We confirm anticipated effects on the known main target, thymidylate synthase (TYMS), and enzymes in pyrimidine metabolism and DNA damage pathways. However, most interaction changes we see are for proteins previously not associated with the MoA of 5-FU, including wide-ranging effects on RNA-modification and -processing pathways. Attenuated responses of specific proteins in a resistant cell model identify key components of the 5-FU MoA, where intriguingly the abrogation of TYMS inhibition is not required for cell proliferation.

New insights into the mechanisms underlying 5-fluorouracil-induced intestinal toxicity based on transcriptomic and metabolomic responses in human intestinal organoids

5-Fluorouracil (5-FU) is a widely used chemotherapeutical that induces acute toxicity in the small and large intestine of patients. Symptoms can be severe and lead to the interruption of cancer treatments. However, there is limited understanding of the molecular mechanisms underlying 5-FU-induced intestinal toxicity. In this study, well-established 3D organoid models of human colon and small intestine (SI) were used to characterize 5-FU transcriptomic and metabolomic responses. Clinically relevant 5-FU concentrations for in vitro testing in organoids were established using physiologically based pharmacokinetic simulation of dosing regimens recommended for cancer patients, resulting in exposures to 10, 100 and 1000 µM. After treatment, different measurements were performed: cell viability and apoptosis; image analysis of cell morphological changes; RNA sequencing; and metabolome analysis of supernatant from organoids cultures. Based on analysis of the differentially expressed genes, the most prominent molecular pathways affected by 5-FU included cell cycle, p53 signalling, mitochondrial ATP synthesis and apoptosis. Short time-series expression miner demonstrated tissue-specific mechanisms affected by 5-FU, namely biosynthesis and transport of small molecules, and mRNA translation for colon; cell signalling mediated by Rho GTPases and fork-head box transcription factors for SI. Metabolomic analysis showed that in addition to the effects on TCA cycle and oxidative stress in both organoids, tissue-specific metabolic alterations were also induced by 5-FU. Multi-omics integration identified transcription factor E2F1, a regulator of cell cycle and apoptosis, as the best key node across all samples. These results provide new insights into 5-FU toxicity mechanisms and underline the relevance of human organoid models in the safety assessment in drug development.

MicroRNA-497-5p Is Downregulated in Hepatocellular Carcinoma and Associated with Tumorigenesis and Poor Prognosis in Patients

Background

MicroRNAs (miRNAs) have been demonstrated to exhibit important regulatory roles in multiple malignancies, including hepatocellular carcinoma (HCC). hsa-miR-497-5p was reported to involve in cancer progression and poor prognosis in many kinds of tumors. However, the expression and its clinical significance of hsa-miR-497-5p in HCC remain unclear.

Methods

In the present study, we investigated the expression of hsa-miR-497-5p in HCC and analyzed the correction of clinical features with prognosis. The expression levels of hsa-miR-497-5p and potential target genes were analyzed in HCC and adjacent noncancerous tissues using The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) datasets. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to analyze hsa-miR-497-5p levels in 328 HCC tissues and 30 paired adjacent noncancer tissues. Overall survival (OS) and progression-free survival (PFS) of patients with HCC were assessed using the Kaplan-Meier method and the log-rank test.

Results

The hsa-miR-497-5p expression levels were decreased, and its target genes ACTG1, CSNK1D, PPP1CC, and BIRC5 were upregulated in HCC tissues compared with normal tissues. Lower levels of hsa-miR-497-5p expression and higher levels of the four target genes were significantly associated with higher tumor diameter. Moreover, patients with lower hsa-miR-497-5p expression and higher target genes levels had shorter OS.

Conclusion

The expression levels of hsa-miR-497-5p may play an important regulatory role in HCC and are closely correlated with HCC progression and poor prognosis in patients. The hsa-miR-497-5p may be a specific therapeutic target for the treatment of HCC.

Functional metabolomics reveal the role of AHR/GPR35 mediated kynurenic acid gradient sensing in chemotherapy-induced intestinal damage

Intestinal toxicity induced by chemotherapeutics has become an important reason for the interruption of therapy and withdrawal of approved agents. In this study, we demonstrated that chemotherapeutics-induced intestinal damage were commonly characterized by the sharp upregulation of tryptophan (Trp)−kynurenine (KYN)−kynurenic acid (KA) axis metabolism. Mechanistically, chemotherapy-induced intestinal damage triggered the formation of an interleukin-6 (IL-6)−indoleamine 2,3-dioxygenase 1 (IDO1)−aryl hydrocarbon receptor (AHR) positive feedback loop, which accelerated kynurenine pathway metabolism in gut. Besides, AHR and G protein-coupled receptor 35 (GPR35) negative feedback regulates intestinal damage and inflammation to maintain intestinal integrity and homeostasis through gradually sensing kynurenic acid level in gut and macrophage, respectively. Moreover, based on virtual screening and biological verification, vardenafil and linagliptin as GPR35 and AHR agonists respectively were discovered from 2388 approved drugs. Importantly, the results that vardenafil and linagliptin significantly alleviated chemotherapy-induced intestinal toxicity in vivo suggests that chemotherapeutics combined with the two could be a promising therapeutic strategy for cancer patients in clinic. This work highlights GPR35 and AHR as the guardian of kynurenine pathway metabolism and core component of defense responses against intestinal damage.

Long Noncoding RNA OIP5-AS1 Promotes the Progression of Liver Hepatocellular Carcinoma via Regulating the hsa-miR-26a-3p/EPHA2 Axis

Numerous studies have suggested that dysregulated long noncoding RNAs (lncRNAs) contributed to the development and progression of many cancers. lncRNA OIP5 antisense RNA 1 (OIP5-AS1) has been reported to be increased in several cancers. However, the roles of OIP5-AS1 in liver hepatocellular carcinoma (LIHC) remain to be investigated. In this study, we demonstrated that OIP5-AS1 was upregulated in LIHC tissue specimens and its overexpression was associated with the poor survival of patients with LIHC. Furthermore, loss-of function experiments indicated that OIP5-AS1 promoted cell proliferation and inhibited cell apoptosis both in vitro and in vivo. Moreover, binding sites between OIP5-AS1 and hsa-miR-26a-3p as well as between hsa-miR-26a-3p and EPHA2 were confirmed by luciferase assays. Finally, a rescue assay was performed to prove the effect of the OIP5-AS1/hsa-miR-26a-3p/EPHA2 axis on LIHC cell biological behaviors. Based on all of the above findings, our results suggested that OIP5-AS1 promoted LIHC cell proliferation and invasion via regulating the hsa-miR-26a-3p/EPHA2 axis.

High-Throughput Transcriptome Profiling in Drug and Biomarker Discovery

The development of new drugs is multidisciplinary and systematic work. High-throughput techniques based on “-omics” have driven the discovery of biomarkers in diseases and therapeutic targets of drugs. A transcriptome is the complete set of all RNAs transcribed by certain tissues or cells at a specific stage of development or physiological condition. Transcriptome research can demonstrate gene functions and structures from the whole level and reveal the molecular mechanism of specific biological processes in diseases. Currently, gene expression microarray and high-throughput RNA-sequencing have been widely used in biological, medical, clinical, and drug research. The former has been applied in drug screening and biomarker detection of drugs due to its high throughput, fast detection speed, simple analysis, and relatively low price. With the further development of detection technology and the improvement of analytical methods, the detection flux of RNA-seq is much higher but the price is lower, hence it has powerful advantages in detecting biomarkers and drug discovery. Compared with the traditional RNA-seq, scRNA-seq has higher accuracy and efficiency, especially the single-cell level of gene expression pattern analysis can provide more information for drug and biomarker discovery. Therefore, (sc)RNA-seq has broader application prospects, especially in the field of drug discovery. In this overview, we will review the application of these technologies in drug, especially in natural drug and biomarker discovery and development. Emerging applications of scRNA-seq and the third generation RNA-sequencing tools are also discussed.