Gut-Restricted Selective Cyclooxygenase-2 (COX-2) Inhibitors for Chemoprevention of Colorectal Cancer

Mechanism study of oleanolic acid derivative, K73-03, inducing cell apoptosis in hepatocellular carcinoma

Oleanolic acid (3β-hydroxyolean-12-en-28-oic acid, OA) is a kind of pentacyclic triterpene, which widely distributes in nature. OA possesses a powerful anti-cancer effect; however, its low solubility limits its bioavailability and application. In this study, a new OA derivative, K73-03, was used to determine its effect on liver cancer cells and detailed molecular mechanisms. Here, we show that K73-03 may lead to the disorder of mitochondria in HepG2 cells, leading to excessive ROS production and apoptosis in cells. Meanwhile, K73-03 could induce cell apoptosis by inhibiting JAK2/STAT3 pathway and NF-κB/P65 pathway. Collectively, this study may provide a preliminary basis for further cancer treatment of hepatocellular carcinoma.

COX 2-inhibitors; a thorough and updated survey into combinational therapies in cancers

Cyclooxygenase (COX) enzymes are pivotal in inflammation and cancer development. COX-2, in particular, has been implicated in tumor growth, angiogenesis, and immune evasion. Recently, COX-2 inhibitors have arisen as potential therapeutic agents in cancer treatment. In addition, combining COX inhibitors with other treatment modalities has demonstrated the potential to improve therapeutic efficacy. This review aims to investigate the effects of COX inhibition, both alone and in combination with other methods, on signaling pathways and carcinogenesis in various cancers. In this study, a literature search of all major academic databases was conducted (PubMed, Scholar google), including the leading research on the mechanisms of COX-2, COX-2 inhibitors, monotherapy with COX-2 inhibitors, and combining COX-2-inhibitors with chemotherapeutic agents in tumors. The study encompasses preclinical and clinical evidence, highlighting the positive findings and the potential implications for clinical practice. According to preclinical studies, multiple signaling pathways implicated in tumor cell proliferation, survival, invasion, and metastasis can be suppressed by inhibiting COX. In addition, combining COX inhibitors with chemotherapy drugs, targeted therapies, immunotherapies, and miRNA-based approaches has enhanced anti-tumor activity. These results suggest that combination therapy has the potential to overcome resistance mechanisms and improve treatment outcomes. However, caution must be exercised when selecting and administering combination regimens. Not all combinations of COX-2 inhibitors with other drugs result in synergistic effects; some may even have unfavorable interactions. Therefore, personalized approaches that consider the specific characteristics of the cancer and the medications involved are crucial for optimizing therapeutic strategies. In conclusion, as monotherapy or combined with other methods, COX inhibition bears promise in modulating signaling pathways and inhibiting carcinogenesis in various cancers. Additional studies and well-designed clinical trials are required to completely elucidate the efficacy of COX inhibition and combination therapy in enhancing cancer treatment outcomes. This narrative review study provides a detailed summary of COX-2 monotherapy and combination targeted therapy in cancer treatment.

Lactobacillus plantarum Zhang-LL Inhibits Colitis-Related Tumorigenesis by Regulating Arachidonic Acid Metabolism and CD22-Mediated B-Cell Receptor Regulation

Colorectal cancer (CRC) is a significant health concern and is the third most commonly diagnosed and second deadliest cancer worldwide. CRC has been steadily increasing in developing countries owing to factors such as aging and epidemics. Despite extensive research, the exact pathogenesis of CRC remains unclear, and its causes are complex and variable. Numerous in vitro, animal, and clinical trials have demonstrated the efficacy of probiotics such as Lactobacillus plantarum in reversing the adverse outcomes of CRC. These findings suggest that probiotics play vital roles in the prevention, adjuvant treatment, and prognosis of CRC. In this study, we constructed a mouse model of CRC using an intraperitoneal injection of azomethane combined with dextran sodium sulfate, while administering 5-fluorouracil as well as high- and low-doses of L. plantarum Zhang-LL live or heat-killed strains. Weight changes and disease activity indices were recorded during feeding, and the number of polyps and colon length were measured after euthanasia. HE staining was used to observe the histopathological changes in the colons of mice, and ELISA was used to detect the expression levels of IL-1β, TNF-α, and IFN-γ in serum. To investigate the specific mechanisms involved in alleviating CRC progression, gut microbial alterations were investigated using 16S rRNA amplicon sequencing and non-targeted metabolomics, and changes in genes related to CRC were assessed using eukaryotic transcriptomics. The results showed that both viable and heat-killed strains of L. plantarum Zhang-LL in high doses significantly inhibited tumorigenesis, colon shortening, adverse inflammatory reactions, intestinal tissue damage, and pro-inflammatory factor expression upregulation. Specifically, in the gut microbiota, the abundance of the dominant flora Acutalibacter muris and Lactobacillus johnsonii was regulated, PGE2 expression was significantly reduced, the arachidonic acid metabolism pathway was inhibited, and CD22-mediated B-cell receptor regulation-related gene expression was upregulated. This study showed that L. plantarum Zhang-LL live or heat-inactivated strains alleviated CRC progression by reducing the abundance of potentially pathogenic bacteria, increasing the abundance of beneficial commensal bacteria, mediating the arachidonic acid metabolism pathway, and improving host immunogenicity.

Integrated gut microbiota and metabolome analysis reveals the mechanism of Xiaoai Jiedu recipe in ameliorating colorectal cancer

Introduction

Xiaoai Jiedu recipe (XJR), a classical prescription of traditional Chinese medicine (TCM), has been clinically proven to be effective in ameliorating colorectal cancer (CRC). However, its exact mechanism of action is still elusive, limiting its clinical application and promotion to a certain extent. This study aims to evaluate the effect of XJR on CRC and further illustrate mechanism underlying its action.

Methods

We investigated the anti-tumor efficacy of XJR in vitro and vivo experiments. An integrated 16S rRNA gene sequencing and UPLC-MS based metabolomics approach were performed to explore possible mechanism of XJR anti-CRC on the gut microbiota and serum metabolic profiles. The correlation between altered gut microbiota and disturbed serum metabolites was investigated using Pearson's correlation analysis.

Results

XJR effectively displayed anti-CRC effect both in vitro and in vivo. The abundance of aggressive bacteria such as Bacteroidetes, Bacteroides, and Prevotellaceae decreased, while the levels of beneficial bacteria increased (Firmicutes, Roseburia, and Actinobacteria). Metabolomics analysis identified 12 potential metabolic pathways and 50 serum metabolites with different abundances possibly affected by XJR. Correlation analysis showed that the relative abundance of aggressive bacteria was positively correlated with the levels of Arachidonic acid, Adrenic acid, 15(S)-HpETE, DL-Arginine, and Lysopc 18:2, which was different from the beneficial bacteria.

Discussion

The regulation of gut microbiota and related metabolites may be potential breakthrough point to elucidate the mechanism of XJR in the treatment of the CRC. The strategy employed would provide theoretical basis for clinical application of TCM.

Retrospective efficacy analysis of olaparib combined with bevacizumab in the treatment of advanced colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is a highly prevalent malignancy of the digestive tract worldwide, characterized by a significant morbidity and mortality rate and subtle initial symptoms. Diarrhea, local abdominal pain, and hematochezia occur with the development of cancer, while systemic symptoms such as anemia and weight loss occur in patients with advanced CRC. Without timely interventions, the disease can have fatal consequences within a short span. The current therapeutic options for colon cancer include olaparib and bevacizumab, which are widely utilized. This study intends to evaluate the clinical efficacy of olaparib combined with bevacizumab in the treatment of advanced CRC, hoping to provide insights into advanced CRC treatment.

AIM

To investigate the retrospective efficacy of olaparib combined with bevacizumab in the treatment of advanced CRC.

METHODS

A retrospective analysis was conducted on a cohort of 82 patients with advanced colon cancer who were admitted to the First Affiliated Hospital of the University of South China between January 2018 and October 2019. Among them, 43 patients subjected to the classical FOLFOX chemotherapy regimen were selected as the control group, and 39 patients undergoing treatment with olaparib combined with bevacizumab were selected as the observation group. Subsequent to different treatment regimens, the short-term efficacy, time to progression (TTP), and incidence rate of adverse reactions between the two groups were compared. Changes in serum-related indicators [vascular endothelial growth factor (VEGF), matrix metalloprotein-9 (MMP-9), cyclooxygenase-2 (COX-2)] and tumor markers [human epididymis protein 4 (HE4), carbohydrate antigen 125 (CA125), carbohydrate antigen 199 (CA199)] levels before and after treatment were compared between the two groups at the same time.

RESULTS

The objective response rate was discovered to be 82.05%, and the disease control rate was 97.44% in the observation group, which were significantly higher than the respective rates of 58.14% and 83.72% in the control group (P < 0.05). The median TTP was 24 mo (95%CI: 19.987-28.005) in the control group and 37 mo (95%CI: 30.854-43.870) in the observation group. The TTP in the observation group was significantly better than that in the control group, and the difference held statistical significance (log-rank test value = 5.009, P = 0.025). Before treatment, no substantial difference was detected in serum VEGF, MMP-9, and COX-2 levels and tumor markers HE4, CA125, and CA199 levels between the two groups (P > 0.05). Following treatment with different regimens, the above indicators in the two groups were remarkably promoted (P < 0.05), VEGF, MMP-9, and COX-2 in the observation group were lower than those in the control group (P < 0.05), and HE4, CA125, and CA199 levels were also lower than those in the control group (P < 0.05). Vis-à-vis the control group, the total incidence of gastrointestinal reactions, thrombosis, bone marrow suppression, liver and kidney function injury, and other adverse reactions in the observation group was notably lowered, with the difference considered statistically significant (P < 0.05).

CONCLUSION

Olaparib combined with bevacizumab in the treatment of advanced CRC demonstrates a strong clinical effect of delaying disease progression and reducing the serum levels of VEGF, MMP-9, COX-2 and tumor markers HE4, CA125 and CA199. Moreover, given its fewer adverse reactions, it can be regarded as a safe and reliable treatment option.

PROTACs in the Management of Prostate Cancer

Cancer treatments with targeted therapy have gained immense interest due to their low levels of toxicity and high selectivity. Proteolysis-Targeting Chimeras (PROTACs) have drawn special attention in the development of cancer therapeutics owing to their unique mechanism of action, their ability to target undruggable proteins, and their focused target engagement. PROTACs selectively degrade the target protein through the ubiquitin-proteasome system, which describes a different mode of action compared to conventional small-molecule inhibitors or even antibodies. Among different cancer types, prostate cancer (PC) is the most prevalent non-cutaneous cancer in men. Genetic alterations and the overexpression of several genes, such as FOXA1, AR, PTEN, RB1, TP53, etc., suppress the immune response, resulting in drug resistance to conventional drugs in prostate cancer. Since the progression of ARV-110 (PROTAC for PC) into clinical phases, the focus of research has quickly shifted to protein degraders targeting prostate cancer. The present review highlights an overview of PROTACs in prostate cancer and their superiority over conventional inhibitors. We also delve into the underlying pathophysiology of the disease and explain the structural design and linkerology strategies for PROTAC molecules. Additionally, we touch on the various targets for PROTAC in prostate cancer, including the androgen receptor (AR) and other critical oncoproteins, and discuss the future prospects and challenges in this field.

Trust Your Gut: Strategies and Tactics for Intestinally Restricted Drugs

Non-absorbable small-molecule drugs targeted to the gut represent an alternative approach to safe, non-systemic therapeutics. Such drugs remain confined to the gastrointestinal tract upon oral dosing by virtue of their limited passive permeability, increasing the local concentration at the site of action while minimizing exposure elsewhere in the body. Herein we review the latest advances in the field of gut-restricted therapeutics, highlighting the different strategies and tactics that medicinal chemists have employed in pursuit of drugs with minimal intestinal absorption.

Novel Benzo[4,5]imidazo[1,2-a]pyrimidine derivatives as selective Cyclooxygenase-2 Inhibitors: Design, synthesis, docking studies, and biological evaluation

The present study was aimed at the synthesis and evaluation of a new series of benzo[4,5]imidazo[1,2-a]pyrimidine having a methylsulfonyl group as COX-2 (cyclooxygenase-2) inhibitor pharmacophore. Molecular modeling studies were performed using the Autodock program, and the results demonstrated that methylsulfonyl pharmacophore was adequately placed into the COX-2 active site. The in vitro and in vivo COX-2 inhibitory effects were also evaluated. In the in vitro assay, all newly synthesized compounds showed moderate to good selectivity for the inhibition of the COX-2 enzyme. However, compound 2-(4-(methylsulfonyl) phenyl)-4-phenylbenzo[4,5]imidazo[1,2-a]pyrimidine (5a) showed the highest COX-2 inhibitory effect (IC₅₀: 0.05 μM) even more than celecoxib as the reference drug (IC₅₀: 0.06 μM). For the in vivo study, the writing reflex test was used, and the results indicated that all synthesized compounds had well dose-dependent anti-nociceptive activity. The in vivo evaluation also showed that compound 2-(4-(methylsulfonyl)phenyl)-4-(p-tolyl)benzo[4,5]imidazo[1,2-a]pyrimidine (5d) had the highest activity in the writing reflex test (ED₅₀: 5.75 mg/kg). In addition, the cytotoxicity effects of the synthesized compounds were tested on MCF-7 breast cancer cells, and all compounds showed considerable inhibitory results.

PARs in the inflammation-cancer transformation of CRC

Colorectal cancer (CRC) is one of the common malignancies with a global trend of increasing incidence and mortality. There is an urgent need to identify new predictive markers and therapeutic targets for the treatment of CRC. Protease-activated receptors (PARs) are a class of G-protein-coupled receptors, with currently identified subtypes including PAR1, PAR2, PAR3 and PAR4. Increasingly, studies suggest that PARs play an important role in the growth and metastasis of CRC. By targeting multiple signaling pathways may contribute to the pathogenesis of CRC. In this review, we first describe recent studies on the role of PARs in CRC inflammation-cancer transformation, focusing on the important role of PARs in signaling pathways associated with inflammation-cancer transformation, and summarize the progress of research on PARs-targeted drugs.

Potent Phenylpyridine and Oxodihydrofuran Inhibitors of Cyclooxygenase-2: Optimization toward a Long Residence Time with Balanced Internal Energetics

Long residence time enzyme inhibitors with a two-step binding mechanism are characterized by a high internal energy barrier for target association. This raises the question of whether optimizing residence time via further increasing this internal energy barrier would inevitably lead to insufficient target occupancy in vivo due to slow, time-dependent binding. We attempted to address this question during optimization of cyclooxygenase-2 (COX-2) inhibitors. Defining long residence time drugs with acceptable association and dissociation rate constants required for sufficient target occupancy and sustained efficacy, which we termed "balanced internal energetics", provides an important criterion for successful progression during lead optimization. Despite the advancement of several COX-2 inhibitors to marketed drugs, their detailed inhibition kinetics have been surprisingly limiting especially during the structure-activity relationship process mainly due to the lack of robust kinetic assays. Herein, we describe a reoptimized COX enzymatic assay and a novel MS-based assay enabling detailed mechanistic studies for identifying long residence time COX-2 inhibitors with balanced internal energetics. These efforts led to the discovery of promising leads possessing dissociation half-lives of ≤40 h, much greater than the values of 6 and 0.71 h for two marketed drugs, etoricoxib and celecoxib, respectively. Importantly, the inhibition rate constants remain comparable to those of the marketed drugs and above the lower limits set by the criteria of balanced internal energetics, predicting sufficient target occupancy required for efficacy. Taken together, this study demonstrates the feasibility of increasing the internal energy barrier as a viable approach for lead optimization toward discovering long residence time drug candidates.