Brassinin enhances the anticancer actions of paclitaxel by targeting multiple signaling pathways in colorectal cancer cells

A novel drug prejudice scaffold-imidazopyridine-conjugate can promote cell death in a colorectal cancer model by binding to β-catenin and suppressing the Wnt signaling pathway

INTRODUCTION

Globally, colorectal cancer (CRC) is the third most common type of cancer, and its treatment frequently includes the utilization of drugs based on antibodies and small molecules. The development of CRC has been linked to various signaling pathways, with the Wnt/β-catenin pathway identified as a key target for intervention.

OBJECTIVES

We have explored the impact of imidazopyridine-tethered chalcone-C (CHL-C) in CRC models.

METHODS

To determine the influence of CHL-C on apoptosis and autophagy, Western blot analysis, annexin V assay, cell cycle analysis, acridine orange staining, and immunocytochemistry were performed. Next, the activation of the Wnt/β-catenin signaling pathway and the anti-cancer effects of CHL-C in vivo were examined in an orthotopic HCT-116 mouse model.

RESULTS

We describe the synthesis and biological assessment of the CHL series as inhibitors of the viability of HCT-116, SW480, HT-29, HCT-15, and SNU-C2A CRC cell lines. Further biological evaluations showed that CHL-C induced apoptosis and autophagy in down-regulated β-catenin, Wnt3a, FZD-1, Axin-1, and p-GSK-3β (Ser9), and up-regulated p-GSK3β (Tyr216) and β-TrCP. In-depth analysis using structure-based bioinformatics showed that CHL-C strongly binds to β-catenin, with a binding affinity comparable to that of ICG-001, a well-known β-catenin inhibitor. Additionally, our in vivo research showed that CHL-C markedly inhibited tumor growth and triggered the activation of both apoptosis and autophagy in tumor tissues.

CONCLUSION

CHL-C is capable of inducing apoptosis and autophagy by influencing the Wnt/β-catenin signaling pathway.

Rujifang inhibits triple-negative breast cancer growth via the PI3K/AKT pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Rujifang (RJF) constitutes a traditional Chinese medicinal compound extensively employed in the management of triple-negative breast cancer (TNBC). However, information regarding its potential active ingredients, antitumor effects, safety, and mechanism of action remains unreported.

AIM OF THE STUDY

To investigate the efficacy and safety of RJF in the context of TNBC.

MATERIALS AND METHODS

We employed the ultra high-performance liquid chromatography-electrospray four-pole time-of-flight mass spectrometry technique (UPLC/Q-TOF-MS/MS) to scrutinize the chemical constituents of RJF. Subcutaneously transplanted tumor models were utilized to assess the impact of RJF on TNBC in vivo. Thirty female BLAB/c mice were randomly divided into five groups: the model group, cyclophosphamide group, and RJF high-dose, medium-dose, and low-dose groups. A total of 1 × 106 4T1 cells were subcutaneously injected into the right shoulder of mice, and they were administered treatments for a span of 28 days. We conducted evaluations on blood parameters, encompassing white blood cell count (WBC), red blood cell count (RBC), hemoglobin (HGB), platelet count (PLT), neutrophils, lymphocytes, and monocytes, as well as hepatorenal indicators including alkaline phosphatase (ALP), glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), albumin, and creatinine (CRE) to gauge the safety of RJF. Ki67 and TUNEL were detected via immunohistochemistry and immunofluorescence, respectively. We prepared RJF drug-containing serum for TNBC cell lines and assessed the in vitro inhibitory effect of RJF on tumor cell growth through the CCK8 assay and cell cycle analysis. RT-PCR was employed to detect the mRNA expression of cyclin-dependent kinase and cyclin-dependent kinase inhibitors in tumor tissues, and Western blot was carried out to ascertain the expression of cyclin and pathway-related proteins.

RESULTS

100 compounds were identified in RJF, which consisted of 3 flavonoids, 24 glycosides, 18 alkaloids, 3 amino acids, 8 phenylpropanoids, 6 terpenes, 20 organic acids, and 18 other compounds. In animal experiments, both CTX and RJF exhibited substantial antitumor effects. RJF led to an increase in the number of neutrophils in peripheral blood, with no significant impact on other hematological indices. In contrast, CTX reduced red blood cell count, hemoglobin levels, and white blood cell count, while increasing platelet count. RJF exhibited no discernible influence on hepatorenal function, whereas Cyclophosphamide (CTX) decreased ALP, GOT, and GPT levels. Both CTX and RJF reduced the expression of Ki67 and heightened the occurrence of apoptosis in tumor tissue. RJF drug-containing serum hindered the viability of 4T1 and MD-MBA-231 cells in a time and concentration-dependent manner. In cell cycle experiments, RJF diminished the proportion of G2 phase cells and arrested the cell cycle at the S phase. RT-PCR analysis indicated that RJF down-regulated the mRNA expression of CDK2 and CDK4, while up-regulating that of P21 and P27 in tumor tissue. The trends in CDKs and CDKIs protein expression mirrored those of mRNA expression. Moreover, the PI3K/AKT pathway displayed downregulation in the tumor tissue of mice treated with RJF.

CONCLUSION

RJF demonstrates effectiveness and safety in the context of TNBC. It exerts anti-tumor effects by arresting the cell cycle at the S phase through the PI3K-AKT pathway.

Brassinin alleviates cancer cachexia by suppressing diverse inflammatory mechanisms in mice

Cancer cachexia is a multifactorial condition that contributes to the death of about 20% of cancer patients. It has the potential to cause weight loss, reduction in muscle mass, and loss of fat tissue, significantly lowering the quality of life. Currently, there are no approved drugs for cancer cachexia. Here, we have explored the possible impact of brassinin (BSN) on cancer cachexia under in vitro and in vivo settings. After differentiation, C2C12 and 3T3-L1 cells were incubated with colorectal carcinoma cells conditioned media or BSN. For preclinical studies, mice were injected with HT-29 cells followed by intraperitoneal administration of BSN, and muscle and adipose tissues were evaluated by Western blotting and hematoxylin and eosin staining. BSN effectively suppressed muscle atrophy by down-regulating the levels of Muscle RING-finger protein-1 and Atrogin-1, while also increasing the expression of myosin heavy chain in cachexia-induced-C2C12 myotubes. The induction of adipogenesis by BSN prevented adipocyte atrophy in cachexia-induced 3T3-L1 adipocytes. We also noted that BSN disrupted the interaction between COX-2 and signaling transducer and activator of transcription 3 (STAT3) promoter, leading to down-regulation of STAT3 activation. Moreover, it was found that BSN inhibited weight loss in mice and demonstrated anti-cachexic effects. Overall, our observations indicate that BSN can attenuate cancer cachexia through diverse mechanisms.

Anticancer Potential of Indole Phytoalexins and Their Analogues

Indole phytoalexins, found in economically significant Cruciferae family plants, are synthesized in response to pathogen attacks or stress, serving as crucial components of plant defense mechanisms against bacterial and fungal infections. Furthermore, recent research indicates that these compounds hold promise for improving human health, particularly in terms of potential anticancer effects that have been observed in various studies. Since our last comprehensive overview in 2016 focusing on the antiproliferative effects of these substances, brassinin and camalexin have been the most extensively studied. This review analyses the multifaceted pharmacological effects of brassinin and camalexin, highlighting their anticancer potential. In this article, we also provide an overview of the antiproliferative activity of new synthetic analogs of indole phytoalexins, which were synthesized and tested at our university with the aim of enhancing efficacy compared to the parent compound.

Enhancing Gastric Cancer Therapeutic Efficacy through Synergistic Cotreatment of Linderae Radix and Hyperthermia in AGS Cells

Gastric cancer remains a global health threat, particularly in Asian countries. Current treatment methods include surgery, chemotherapy, and radiation therapy. However, they all have limitations, such as adverse side effects, tumor resistance, and patient tolerance. Hyperthermia therapy uses heat to selectively target and destroy cancer cells, but it has limited efficacy when used alone. Linderae Radix (LR), a natural compound with thermogenic effects, has the potential to enhance the therapeutic efficacy of hyperthermia treatment. In this study, we investigated the synergistic anticancer effects of cotreatment with LR and 43 °C hyperthermia in AGS gastric cancer cells. The cotreatment inhibited AGS cell proliferation, induced apoptosis, caused cell cycle arrest, suppressed heat-induced heat shock responses, increased reactive oxygen species (ROS) generation, and promoted mitogen-activated protein kinase phosphorylation. N-acetylcysteine pretreatment abolished the apoptotic effect of LR and hyperthermia cotreatment, indicating the crucial role of ROS in mediating the observed anticancer effects. These findings highlight the potential of LR as an adjuvant to hyperthermia therapy for gastric cancer. Further research is needed to validate these findings in vivo, explore the underlying molecular pathways, and optimize treatment protocols for the development of novel and effective therapeutic strategies for patients with gastric cancer.

Combined effects of two phytoalexins, brassinin and camalexin, on the cells of colorectal origin

Brassinin and camalexin belong to phytoalexins, plant compounds generated in the response to stress. Both compounds are known to be cytotoxic to several cancer cell lines, mainly by inducing oxidative stress and subsequent apoptosis. In the presented study, cytotoxic effects of brassinin and camalexin, individually and, for the first time, after combined exposure, on the cells of normal (CCD-Co18) and cancer (Caco-2) lines originated from colorectal tissues and their proapoptotic impact on Caco-2 cells were studied. The determined IC50 values indicate a clearly higher sensitivity of cancer cells to the tested substances, as well as a stronger cytotoxic effect of camalexin than brassinin. The synergistic effect of both phytoalexins was also demonstrated. Caspase-dependent and independent mechanisms were involved in the final effects. Both tested phytoalexins caused evident, concentration-dependent symptoms of oxidative stress in cancer cells, leading to apoptosis, but in the highest concentrations, also to necrosis. In case of camalexin, signs of pyroptosis were additionally detected.

The Apoptotic and Anti-Warburg Effects of Brassinin in PC-3 Cells via Reactive Oxygen Species Production and the Inhibition of the c-Myc, SIRT1, and β-Catenin Signaling Axis

Though Brassinin is known to have antiangiogenic, anti-inflammatory, and antitumor effects in colon, prostate, breast, lung, and liver cancers, the underlying antitumor mechanism of Brassinin is not fully understood so far. Hence, in the current study, the apoptotic mechanism of Brassinin was explored in prostate cancer. Herein, Brassinin significantly increased the cytotoxicity and reduced the expressions of pro-Poly ADP-ribose polymerase (PARP), pro-caspase 3, and B-cell lymphoma 2 (Bcl-2) in PC-3 cells compared to DU145 and LNCaP cells. Consistently, Brassinin reduced the number of colonies and increased the sub-G1 population and terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL)-positive cells in the PC-3 cells. Of note, Brassinin suppressed the expressions of pyruvate kinase-M2 (PKM2), glucose transporter 1 (GLUT1), hexokinase 2 (HK2), and lactate dehydrogenase (LDH) as glycolytic proteins in the PC-3 cells. Furthermore, Brassinin significantly reduced the expressions of SIRT1, c-Myc, and β-catenin in the PC-3 cells and also disrupted the binding of SIRT1 with β-catenin, along with a protein-protein interaction (PPI) score of 0.879 and spearman's correlation coefficient of 0.47 being observed between SIRT1 and β-catenin. Of note, Brassinin significantly increased the reactive oxygen species (ROS) generation in the PC-3 cells. Conversely, ROS scavenger NAC reversed the ability of Brassinin to attenuate pro-PARP, pro-Caspase3, SIRT1, and β-catenin in the PC-3 cells. Taken together, these findings support evidence that Brassinin induces apoptosis via the ROS-mediated inhibition of SIRT1, c-Myc, β-catenin, and glycolysis proteins as a potent anticancer candidate.

Sphingosine kinase-2 silencing modulates sensitivity of HT-29 human colorectal cancer cells to paclitaxel-induced cell death through altering apoptosis-related proteins

The sphingosine kinase-2 (SphK2), a main component of sphingolipid signal transduction, is reported as an innovative therapeutic candidate for cancer treatment. This study was conducted to investigate the suppression of SphK2 in increasing HT-29 colorectal cancer cells sensitivity to paclitaxel via inducing apoptosis and targeting c-FLIPS, MCL-1, and survivin expressions. Cells were transfected with siRNA against SphK2, PTX, or SphK2 activator. Proliferation and apoptosis were evaluated by MTT assay, and trypan blue staining and ELISA, respectively. SphK2, c-FLIPS, MCL-1, and survivin expression were determined by qRT-PCR and Western blotting. SphK2 siRNA increased cell death induced PTX. SphK2 agonist abolished silencing impact on cell survival. We found down-expression of C-FLIPS, MCL-1, and survivin by SphK2 siRNA transfection either alone or in paclitaxel treated cells, as well as elevation in cell apoptosis. Our results showed that SphK2 suppression may be an effective important modality to enhance cell sensitivity to paclitaxel via the induction of apoptosis in colorectal cancers.

Brassinin Induces Apoptosis, Autophagy, and Paraptosis via MAPK Signaling Pathway Activation in Chronic Myelogenous Leukemia Cells

Brassinin (BSN), a potent phytoalexin found in cruciferous vegetables, has been found to exhibit diverse anti-neoplastic effects on different cancers. However, the impact of BSN on chronic myelogenous leukemia (CML) cells and the possible mode of its actions have not been described earlier. We investigated the anti-cytotoxic effects of BSN on the KBM5, KCL22, K562, and LAMA84 CML cells and its underlying mechanisms of action in inducing programmed cell death. We noted that BSN could induce apoptosis, autophagy, and paraptosis in CML cells. BSN induced PARP cleavage, subG1 peak increase, and early apoptosis. The potential action of BSN on autophagy activation was confirmed by an LC3 expression and acridine orange assay. In addition, BSN induced paraptosis through increasing the reactive oxygen species (ROS) production, mitochondria damage, and endoplasmic reticulum (ER) stress. Moreover, BSN promoted the activation of the MAPK signaling pathway, and pharmacological inhibitors of this signaling pathway could alleviate all three forms of cell death induced by BSN. Our data indicated that BSN could initiate the activation of apoptosis, autophagy, and paraptosis through modulating the MAPK signaling pathway.

Brassinin Abundant in Brassicaceae Suppresses Melanogenesis through Dual Mechanisms of Tyrosinase Inhibition

Brassinin is a phytoalexin abundant in plants, especially in cabbage, and has been reported to act as an anti-cancer and anti-inflammatory agent. However, limited studies are available to elucidate the functionalities of brassinin. Here, we tested the effects of brassinin on melanogenesis using cell-free and cell-based biochemical analysis and docking simulation. Cell-free experiments exhibited that brassinin has antioxidant and anti-tyrosinase activities. When applied to B16F10 cells stimulated with a melanogenesis inducer α-MSH, brassinin pretreatment significantly reduced melanin accumulation and cellular tyrosinase activity. Docking simulation indicates that the docking score of brassinin to the binding pocket of tyrosinase is better than that of kojic acid or arbutin, anti-melanogenic positive controls, indicating that brassinin inhibits melanogenesis at least partially by binding to and inactivating tyrosinase. In addition, qPCR results showed that brassinin reduced tyrosinase mRNA levels. Together, these results suggest that brassinin exerts anti-melanogenesis effects by inhibiting both the activity and mRNA expression levels of tyrosinase. Therefore, our study showed that brassinin has the potential to be used in pharmaceutical or cosmetic products for depigmentation.

In Vitro Efficacy of Extracts and Isolated Bioactive Compounds from Ascomycota Fungi in the Treatment of Colorectal Cancer: A Systematic Review

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide. Despite the advances and success of current treatments (e.g., chemotherapy), there are multiple serious side effects which require the development of new treatment strategies. In recent years, fungi have gained considerable attention as a source of extracts and bioactive compounds with antitumor capabilities because of their antimicrobial and antioxidant properties and even their anti-inflammatory and antiviral activities. In the present review, a systematic search of the existing literature in four electronic databases was carried out in which the antitumor activity against CRC cells of Ascomycota fungi extracts or compounds was tested. The systematical research in the four databases resulted in a total of 883 articles. After applying exclusion and inclusion criteria, a total of 75 articles were finally studied. The order Eurotiales was the most studied (46% of the articles), and the ethyl acetate extraction was the most used method (49% of the papers). Penicillium extracts and gliotoxin and acetylgliotoxin G bioactive compounds showed the highest cytotoxic activity. This review also focuses on the action mechanisms of the extracts and bioactive compounds of fungi against CRC, which were mediated by apoptosis induction and the arrest of the cell cycle, which induces a notable reduction in the CRC cell proliferation capacity, and by the reduction in cell migration that limits their ability to produce metastasis. Thus, the ability of fungi to induce the death of cancer cells through different mechanisms may be the basis for the development of new therapies that improve the current results, especially in the more advanced stages of the CCR.

Tanshinone IIA exerts autophagic cell death through down-regulation of β-catenin in renal cell carcinoma cells

Renal cell carcinoma (RCC), also called kidney cancer, is one of the most common malignancies worldwide, including the United States and China. Because of the characteristics of RCC that are both insidious and largely insensitive to chemo-radiation, the incidence and mortality of RCC are increasing every year. However, there are few studies describing anti-cancer effects of the natural compounds on RCC as compared to other cancers. Here, we analyzed the anti-neoplastic impact of Tanshinone IIA (TSN) on RCC cells. We noted that TSN increased the expression of LC3 proteins while having little effect on PARP and Alix protein expression. We found that TSN up-regulated the expression of autophagy-related proteins such as Atg7 and Beclin-1. Moreover, TSN promoted the formation of autophagic vacuoles such as autophagosomes and autolysosomes. However, treatment with 3-Methyladenine (3-MA) or Chloroquine (CQ), slightly decreased the ability of TSN to induce autophagy, but still autophagy occurred. In addition, TSN inhibited translocation of β-catenin into the nucleus, and β-catenin deletion and TSN treatment in RCC increased the expression of LC3 protein. Overall our findings indicate that TSN can exert significant anti-tumor effects through down-regulation of β-catenin to induce autophagic cell death.

Brassinin Enhances Apoptosis in Hepatic Carcinoma by Inducing Reactive Oxygen Species Production and Suppressing the JAK2/STAT3 Pathway

Plants from the family Brassicaceae produce brassinin (BSN), which is an essential indole phytoalexin. BSN can kill certain types of cancer cells. Using hepatocarcinoma (HCC) cells, we examined the molecular mechanisms of BSN. We found that HCC cell growth was suppressed and apoptosis was induced by BSN via the downregulation of the JAK/STAT3 pathway. The cytoplasmic latent transcription factor STAT3, belonging to the STAT family, acted as both a signal transducer and an activator and was linked to tumor progression and decreased survival. BSN incubation caused HCC cells to produce reactive oxygen species (ROS). By activating caspase-9/-3 and PARP cleavage, Bcl-2 was reduced, and apoptosis was increased. BSN inhibited constitutive STAT3, JAK2, and Src phosphorylation. The JAK/STAT signaling cascade was confirmed by siRNA silencing STAT3 in HCC cells. BSN also suppressed apoptosis by Z-Val-Ala-Asp-Fluoromethylketone (Z-VAD-FMK), an apoptotic inhibitor. N-acetylcysteine (NAC) inhibited the production of ROS and diminished BSN-induced apoptosis. Our findings suggested that BSN has potential as a treatment for cancer.

Taxus wallichiana var. chinensis (Pilg.) Florin Aqueous Extract Suppresses the Proliferation and Metastasis in Lung Carcinoma via JAK/STAT3 Signaling Pathway

As one of the most common neoplasms globally, lung cancer (LC) is the leading cause of cancer-related mortality. Recurrence and metastasis negatively influencing therapeutic efficacy and overall survival demand new strategies in LC treatment. The advantages of TCM are increasingly highlighted. In this study, we obtained the major chemical components and their ratios in the aqueous extract of Taxus wallichiana var. chinensis (Pilg.) Florin (AETW) by UPLC-Q/TOF-MS/MS detection. The CCK-8 assay revealed that AETW could selectively inhibit the growth of A549 and HCC827 cells in a dose-dependent manner with little effect on normal human lung cells. Moreover, both in vitro and in vivo experiments showed that AETW was able to suppress the capacities of cell migration and invasion and downregulate the EMT and the JAK/STAT3 signaling pathway. To further probe into the molecular mechanism, the overexpression of STAT3 was performed into LC cells with AETW treatment, which counteracted the inhibitory effect on malignant behaviors of A549 and HCC827 cells with the decline in the expressions of p-JAK and p-STAT3. Taken together, we propose that AETW may inhibit the proliferation and metastasis by inactivating the JAK/STAT3 axis.