Cucurbitacin I inhibits cell migration and invasion and enhances chemosensitivity in colon cancer

JSI-124 Induces Cell Cycle Arrest and Regulates the Apoptosis in Glioblastoma Cells

Cucurbitacin I (JSI-124), derived from Cucurbitaceae, has shown the potential to induce apoptosis and cell cycle arrest in some cancer cells. However, the effect of JSI-124 on glioblastoma multiforme (GBM) cell cycle and apoptosis is still unclear. Our investigation revealed that JSI-124 effectively reduced cell viability in GBM cells, leading to apoptosis and increased caspase-3 activity. Intriguingly, JSI-124 caused the accumulation of G2/M phase to regulate cell cycle, confirmed by MPM-2 staining and increased protein synthesis during mitosis by mitotic index analysis. Western blot analysis found that JSI-124 affected the progression of G2/M arrest by downregulating the CDK1 and upregulating the cyclinB1, suggesting that JSI-124 disrupted the formation and function of the cyclin B1/CDK1 complex in GBM8401 and U87MG cells. However, we found the JSI-124-regulated cell cycle G2/M and apoptosis-relative gene in GBM8401 and U87MG cells by NGS data analysis. Notably, we found that the GBM8401 and U87MG cells observed regulation of apoptosis and cell-cycle-related signaling pathways. Taken together, JSI-124 exhibited the ability to induce G2/M arrest, effectively arresting the cell cycle at critical stages. This arrest is accompanied by the initiation of apoptosis, highlighting the dual mechanism of action of JSI-124. Collectively, our findings emphasize that JSI-124 holds potential as a therapeutic agent for GBM by impeding cell cycle progression, inhibiting cell proliferation, and promoting apoptosis. As demonstrated by our in vitro experiments, these effects are mediated through modulation of key molecular targets.

Recent Advances in the Application of Cucurbitacins as Anticancer Agents

Cucurbitacins are tetracyclic triterpenoid secondary metabolites, widely distributed in the Cucurbitaceae family. These bitter-tasting compounds act primarily as defense mechanisms against external injuries, and thus against herbivores, and furthermore, they have also found use in folk medicine in the treatment of various diseases. Many studies have acknowledged significant biological activities of cucurbitacins, such as antioxidant and anti-inflammatory activities, antimicrobial properties, or antitumor potential. Overall, cucurbitacins have the ability to inhibit cell proliferation and induce apoptosis in various cancer cell lines. Both in vitro and in vivo studies were performed to evaluate the anticancer activity of varied cucurbitacins. Cucurbitacins offer a promising avenue for future cancer treatment strategies, and their diverse mechanisms of action make them attractive candidates for further investigation. The aim of the present study is to shed light on the chemical diversity of this group of compounds by providing the sources of origin of selected compounds and their chemical structure, as well as insight into their anticancer potential. In addition, within this paper molecular targets for cucurbitacins and signalling pathways important for cancer cell proliferation and/or survival that are affected by the described class of compounds have been presented.

Cucumis sativus (Cucurbitaceae) seed oil prevents benzo(a)pyrene-induced prostate cancer in vitro and in vivo

Despite enormous progress in modern medicine, prostate cancer (PCa) remains a major public health problem due to its high incidence and mortality. Although studies have shown in vitro antitumor effects of cucurbitacins from Cucumis sativus, the in vivo anticancer effect of the seed oil as a whole, has yet to be demonstrated. The present study evaluated the in vitro anticancer mechanisms of C. sativus (CS) seed oil and its possible chemopreventive potential on benzo(a)pyrene (BaP)-induced PCa in Wistar rat. In vitro cell growth, clone formation, cell death mechanism, cell adhesion and migration as well as expression of integrins β-1 and β-4 were assessed. In vivo PCa was induced in 56 male rats versus 8 normal control rats, randomized in normal (NOR) and negative (BaP) control groups which, received distilled water; the positive control group (Caso) was treated with casodex (13.5 mg/kg BW). One group received the total seed extract at the dose of 500 mg/kg BW; while the remaining three groups were treated with CS seed oil at 42.5, 85, and 170 mg/kg BW. The endpoints were: morphologically (prostate tumor weight and volume), biochemically (total protein, prostate specific antigen (PSA), oxidative stress markers such as MDA, GSH, catalase, and SOD) and histologically. As results, CS seed oil significantly and concentration-dependently reduced the DU145 prostate cancer cell growth and clone formation (optimum = 100 μg/mL). It slightly increased the number of apoptotic cells and inhibited the migration and invasion of DU145 cells, while it decreased their adhesion to immobilized collagen and fibrinogen. The expression of integrin β-1 and β-4 was increased in presence of 100 μg/mL CS oil. In vivo, the BaP significantly elevated the incidence of PC tumors (75%), the total protein and PSA levels, pro-inflammatory cytokines (TNF-α, IL-1, and IL-6) and MDA levels compared to NOR. CS seeds oil significantly counteracted the effect of BaP by decreasing significantly the PC incidence (12.5%), and increasing the level of antioxidant (SOD, GSH, and catalase) and anti-inflammatory cytokine IL-10 in serum. While in BaP group PCa adenocarninoma was the most representative neoplasm, rats treated with 85 and 170 mg/kg prevented it in the light of the casodex. It is conclude that CS may provide tumor suppressive effects in vitro and in vivo which makes it an interesting candidate to support the current treatment protocol.

Pharmacokinetics and Biological Activity of Cucurbitacins

Cucurbitacins are a class of secondary metabolites initially isolated from the Cucurbitaceae family. They are important for their analgesic, anti-inflammatory, antimicrobial, antiviral, and anticancer biological actions. This review addresses pharmacokinetic parameters recently reported, including absorption, metabolism, distribution, and elimination phases of cucurbitacins. It includes recent studies of the molecular mechanisms of the biological activity of the most studied cucurbitacins and some derivatives, especially their anticancer capacity, to propose the integration of the pharmacokinetic profiles of cucurbitacins and the possibilities of their use. The main botanical genera and species of American origin that have been studied, and others whose chemo taxonomy makes them essential sources for the extraction of these metabolites, are summarized.

Cucurbitacin I exhibits anticancer efficacy through induction of apoptosis and modulation of JAK/STAT3, MAPK/ERK, and AKT/mTOR signaling pathways in HepG2 cell line

Hepatocellular carcinoma is a common cancer type, especially among men. Although cucurbitacin I (CuI), widely found in plants belonging to the Ecballium elaterium (E. L) plant family, has been shown to have antitumorigenic properties in many cancer types, its anticancer effect, molecular mechanism, and apoptotic effect mediated by signal pathways on hepatocellular carcinoma have not been fully clarified. In the present study, we investigated the anticancer effect of CuI treated at different doses on the HepG2 cell line and the underlying mechanism in vitro. High-purity CuI was obtained from the E. elaterium plant with the aid of HPLC. The effects of this substance on the viability of cells were studied by the MTT assay. The effects of CuI on cell cycle progression and apoptosis were studied with flow cytometry. DNA breaks were analyzed by the Comet assay method. The proteins and genes involved in the JAK/STAT3, MAPK/ERK, and AKT/mTOR signaling pathways were investigated using Western blot and qRT-PCR, respectively. The results of this study demonstrated that CuI significantly reduced HepG2 cell growth in vitro, induced antiproliferation, and G2/M phase of the cell cycle was interrupted. PRACTICAL APPLICATIONS: CuI administration was shown to downregulate the levels of proteins in the PI3K/AKT/mTOR, MAPK, and JAK2/STAT3 cascades in HepG2 cells. CuI also reduced the expression of MAPK, STAT3, mTOR, JAK2, and Akt genes in different concentrations. DNA breaks are formed as a result of this effect. CuI, by reducing cell proliferation and promoting apoptosis, was found to have potential as a chemotherapeutic agent of hepatocellular carcinoma.

Neuroprotective potential of nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element signaling modulator cucurbitacin I upon glucose and oxygen deprivation/reperfusion (OGD/RP)

This study aimed to investigate the inhibitory effect and mechanism of Cucurbitacin I (Cu I) on apoptosis, oxidative stress, and mitophagy in PC12 cells with glucose and oxygen deprivation/reperfusion (OGD/RP) injury. OGD/RP cell injury model was established by gas anoxic cell incubator and glucose-free medium. The cells were divided into the control group, OGD/RP group, OGD/RP + Cu I group, and OGD/RP + Cu I + 2 µM nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor ML385 group. The results showed that apoptotic rate and reactive oxygen species (ROS) production were significantly increased in OGD/RP group, which were reversed by Cu I pretreatment. Meanwhile, western blot analysis proved that Cu I inhibited OGD/RP-induced mitophagy, manifested as the decreased expression of PTEN-induced kinase 1 (PINK1) and parkin RBR E3 ubiquitin-protein ligase (Parkin), and light chain 3 (LC3) Ⅱ∕LC3 I, as well as the increased expression of P62. Furthermore, immunofluorescence (IF) staining showed that Cu I reduced the co-localized puncta of LC3 with TOM20 in OGD/RP-induced PC12 cells. Similarly, transmission electron microscope finding is consistent with the IF results. Mechanically, after Cu I and OGD/RP treatments, nuclear Nrf2 expression and the levels of downstream target genes were significantly upregulated compared with OGD/RP alone treatment. Nrf2 inhibition reversed the protective effects of Cu I on OGD/RP-induced injury in PC12 cells. The present study provides evidence of the neuroprotective effect of Cu I unraveling its potential as a potential therapeutic candidate for the treatment of ischemic stroke.

Perspectives on natural compounds in chemoprevention and treatment of cancer: an update with new promising compounds

Cancer is the second deadliest disease worldwide. Although recent advances applying precision treatments with targeted (molecular and immune) agents are promising, the histological and molecular heterogeneity of cancer cells and huge mutational burdens (intrinsic or acquired after therapy) leading to drug resistance and treatment failure are posing continuous challenges. These recent advances do not negate the need for alternative approaches such as chemoprevention, the pharmacological approach to reverse, suppress or prevent the initial phases of carcinogenesis or the progression of premalignant cells to invasive disease by using non-toxic agents. Although data are limited, the success of several clinical trials in preventing cancer in high-risk populations suggests that chemoprevention is a rational, appealing and viable strategy to prevent carcinogenesis. Particularly among higher-risk groups, the use of safe, non-toxic agents is the utmost consideration because these individuals have not yet developed invasive disease. Natural dietary compounds present in fruits, vegetables and spices are especially attractive for chemoprevention and treatment because of their easy availability, high margin of safety, relatively low cost and widespread human consumption. Hundreds of such compounds have been widely investigated for chemoprevention and treatment in the last few decades. Previously, we reviewed the most widely studied natural compounds and their molecular mechanisms, which were highly exploited by the cancer research community. In the time since our initial review, many promising new compounds have been identified. In this review, we critically review these promising new natural compounds, their molecular targets and mechanisms of anticancer activity that may create novel opportunities for further design and conduct of preclinical and clinical studies.

Cucurbitacin E and I target the JAK/STAT pathway and induce apoptosis in Sézary cells

Cutaneous T-cell lymphomas and leukemias (CTCLs) are a heterogeneous group of extranodal non-Hodgkin's lymphomas. These are characterized by an accumulation of malignant CD4⁺ T-lymphocytes in the skin, lymph nodes, and peripheral blood. Novel treatment options are needed for patients who progress to advanced stage disease. Cucurbitacin I has previously shown promising results in Sézary syndrome (Sz). A plethora of cucurbitacins, however, have not yet been tested in CTCL. Herein, we investigated the effect of cucurbitacin E and I in two CTCL cell lines. We show that both cucurbitacins decrease viability and cause apoptosis in these cell lines, although HuT-78 was more affected than SeAx (IC₅₀ of 17.38 versus 22.01 μM for cucurbitacin E and 13.36 versus 24.47 μM for cucurbitacin I). Moreover, both cucurbitacins decrease viability of primary cells of a Sz patient (56.46% for cucurbitacin E and 59.07% for cucurbitacin I). Furthermore, while JAK2 inhibition leads to decreased viability in SeAx cells (IC₅₀ of 9.98 and 29.15 μM for AZD1480 and ruxolitinib respectively), both JAK1 and JAK3 do not. This suggests that JAK2 has a preferential role in promoting survival. Western blotting in SeAx cells revealed that both cucurbitacins inhibit STAT3 activation (P < 0.0001), while only cucurbitacin I inhibits STAT5 activation (P = 0.05). This suggests that STAT3 plays a preferential role in the mechanism of action of these cucurbitacins. Nevertheless, a role of STAT5 and JAK2 cannot be excluded and should be explored further. This knowledge could contribute to the development of effective therapies for CTCL and other malignancies involving dysfunction of the JAK/STAT pathway.

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Cucurbitacin E and I decrease viability and cause apoptosis in Sézary cell lines

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Both cucurbitacins decrease viability of primary cells of a Sézary patient

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STAT3 appears to play a role in the mechanism of action of cucurbitacin E and I

STAT3 transcription factor as target for anti-cancer therapy

STATs constitute a large family of transcription activators and transducers of signals that have an important role in many cell functions as regulation of proliferation and differentiation of the cell also regulation of apoptosis and angiogenesis. STAT3 as a member of that family, recently was discovered to have a vital role in progression of different types of cancers. The activation of STAT3 was observed to regulate multiple gene functions during cancer-like cell proliferation, differentiation, apoptosis, metastasis, inflammation, immunity, cell survival, and angiogenesis. The inhibition of STAT3 activation has been an important target for cancer therapy. Inhibitors of STAT3 have been used for a long time for treatment of many types of cancers like leukemia, melanoma, colon, and renal cancer. In this review article, we summarize and discuss different drugs inhibiting the action of STAT3 and used in treatment of different types of cancer.

Naturally occurring anti-cancer compounds: shining from Chinese herbal medicine

Numerous natural products originated from Chinese herbal medicine exhibit anti-cancer activities, including anti-proliferative, pro-apoptotic, anti-metastatic, anti-angiogenic effects, as well as regulate autophagy, reverse multidrug resistance, balance immunity, and enhance chemotherapy in vitro and in vivo. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2011) on the key compounds with anti-cancer effects derived from Chinese herbal medicine (curcumin, epigallocatechin gallate, berberine, artemisinin, ginsenoside Rg3, ursolic acid, silibinin, emodin, triptolide, cucurbitacin B, tanshinone I, oridonin, shikonin, gambogic acid, artesunate, wogonin, β-elemene, and cepharanthine) in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we focused on their recently discovered and/or investigated pharmacological effects, novel mechanism of action, relevant clinical studies, and their innovative applications in combined therapy and immunomodulation. In addition, the present review has extended to describe other promising compounds including dihydroartemisinin, ginsenoside Rh2, compound K, cucurbitacins D, E, I, tanshinone IIA and cryptotanshinone in view of their potentials in cancer therapy. Up to now, the evidence about the immunomodulatory effects and clinical trials of natural anti-cancer compounds from Chinese herbal medicine is very limited, and further research is needed to monitor their immunoregulatory effects and explore their mechanisms of action as modulators of immune checkpoints.

Interaction between laminin-5γ2 and integrin β1 promotes the tumor budding of colorectal cancer via the activation of Yes-associated proteins

Colorectal cancer (CRC) is a common cancer type and a threat to human health. Tumor budding (TB) is the presence of a single cancer cell or clusters of up to five cancer cells prior to the invasive front of an aggressive carcinoma and is an independent prognosis factor for CRC. The molecular mechanism of TB is still unclear, and drugs that inhibit this process are still in the blank stage. This study found that TBs exhibit characteristics of partial EMT with a decreased expression of E-cadherin and no substantial differences in the expression of N-cadherin and vimentin. We also observed the interaction of integrin with extracellular matrix components, laminin-5γ2 (LN-5γ2), play essential roles in the TB of CRC. We then verified that the interaction between LN-5γ2 and integrin β1 promotes the TB of CRC via the activation of FAK and Yes-associated proteins (YAP). A natural drug monomer, cucurbitacin B, was screened using virtual screening methods for the interaction interface of proteins. We found that this monomer could block the interaction interface between LN-5γ2 and integrin β1 and substantially inhibit the TB of CRC cells via inactivation of YAP. This study provides new insights into the mechanism of TB mechanism and the development of drugs targeting the TB of CRC.

Cucurbitacin B exerts anti-cancer activities in human multiple myeloma cells in vitro and in vivo by modulating multiple cellular pathways

Cucurbitacin B (CuB), a triterpenoid compound isolated from the stems of Cucumis melo, has long been used to treat hepatitis and hepatoma in China. Although its remarkable anti-cancer activities have been reported, the mechanism by which it achieves this therapeutic activity remains unclear. This study was designed to investigate the molecular mechanisms by which CuB inhibits cancer cell proliferation. Our results indicate that CuB is a novel inhibitor of Aurora A in multiple myeloma (MM) cells, arresting cells in the G2/M phase. CuB also inhibited IL-10-induced STAT3 phosphorylation, synergistically increasing the anti-tumor activity of Adriamycin in vitro. CuB induced dephosphorylation of cofilin, resulting in the loss of mitochondrial membrane potential, release of cytochrome c, and activation of caspase-8. CuB inhibited MM tumor growth in a murine MM model, without host toxicity. In conclusion, these results indicate that CuB interferes with multiple cellular pathways in MM cells. CuB thus represents a promising therapeutic tool for the treatment of MM.

AKR1C1 Activates STAT3 to Promote the Metastasis of Non-Small Cell Lung Cancer

Metastasis is the leading cause of mortality for human non-small cell lung cancer (NSCLC). However, it is difficult to target tumor metastasis because the molecular mechanisms underlying NSCLC invasion and migration remain unclear. Methods: GEO data analyses and IHC analyses were performed to identify that the expression level of AKR1C1, a member of human aldo-keto reductase family, was highly elevated in patients with metastasis or metastatic foci of NSCLC patients. Functional analyses (in vitro and in vivo) and quantitative genomic analyses were preformed to confirm the pro-metastatic effects of AKR1C1 and the underlying mechanisms. The correlation of AKR1C1 with the prognosis of NSCLC patients was evaluated using Kaplan-Meier analyses. Results: in NSCLC patients, AKR1C1 expression was closely correlated with the metastatic potential of tumors. AKR1C1 overexpression in nonmetastatic cancer cells significantly promoted metastasis both in vitro and in vivo, whereas depletion of AKR1C1 in highly metastatic tumors potently alleviated these effects. Quantitative genomic and functional analyses revealed that AKR1C1 directly interacted with STAT3 and facilitated its phosphorylation-thus reinforcing the binding of STAT3 to the promoter regions of target genes-and then transactivated these genes, which ultimately promoted tumor metastasis. Further studies showed that AKR1C1 might facilitate the interaction of STAT3 with its upstream kinase JAK2. Intriguingly, AKR1C1 exerted these pro-metastatic effects in a catalytic-independent manner. In addition, a significant correlation between AKR1C1 and STAT3 pathway was observed in the metastatic foci of NSCLC patients, and the AKR1C1-STAT3 levels were highly correlated with a poor prognosis in NSCLC patients. Conclusions: taken together, we show that AKR1C1 is a potent inducer of NSCLC metastasis. Our study uncovers the active function of AKR1C1 as a key component of the STAT3 pathway, which promotes lung cancer metastasis, and highlights a candidate therapeutic target to potentially improve the survival of NSCLC patients with metastatic disease.

The anticancer effects of Cucurbitacin I inhibited cell growth of human non‑small cell lung cancer through PI3K/AKT/p70S6K pathway

The present study aimed to identify potential anticancer effects of Cucurbitacin I regulators on cell growth of human non‑small cell lung cancer (NSCLC) and to explore their mechanism. The results indicated that the anticancer effects of Cucurbitacin I markedly attenuated cell proliferation, and induced apoptosis in NSCLC. Furthermore, Cucurbitacin I suppressed phosphatidylinositol‑4,5‑bisphosphate 3‑kinase (PI3K), phosphorylation (p)‑AKT and p‑p70S6K pathway in NSCLC. Then, (PI3K) inhibitor increased anticancer effects of Cucurbitacin I on NSCLC. In conclusion, the present results indicated that Cucurbitacin I inhibited cell growth of human NSCLC through PI3K/AKT/p70S6K signaling pathway.

In vitro investigation of the effect of matrix molecules on the behavior of colon cancer cells under the effect of geldanamycin derivative

The chaperone-binding drug, 17-allylamino-17-demethoxygeldanamycin, has recently come into clinical use. It is a derivative of geldanamycin, an ansamycin benzoquinone antibiotic with anti-carcinogenic effect. Understanding the effect of this drug on the cancer cells and their niche is important for treatment. We applied 17-allylamino-17-demethoxygeldanamycin to colon cancer cell line (Colo 205) on matrix molecules to investigate the relationship of apoptosis with terminal deoxynucleotidyl transferase dUTP nick end labeling immunocytochemistry and related gene expression. We used laminin and collagen I for matrix molecules and vascular endothelial growth factor for angiogenic structure. We also examined apoptosis-related signaling pathway including mitochondrial proteins, cytochrome c, Bcl-2, caspase-9, Apaf-1 expression using real-time polymerase chain reaction. There was clear effect of 17-allylamino-17-demethoxygeldanamycin that killed more cells on tissue culture plastic compared to matrix molecules. The IC₅₀ value was 0.58 µg/mL for tissue culture plastic compared with 0.64 µg/mL for laminin and 0.75 µg/mL for collagen I. The analyses showed that more cells on matrix molecules underwent apoptosis compared to that on tissue culture plastic. Apoptosis-related gene expression was similar in which Bcl-2 expression decreased and proapoptotic gene expression of the cells on matrix molecules increased compared to that on tissue culture plastic. However, the application of 17-allylamino-17-demethoxygeldanamycin was more effective for the cells on collagen I compared to the cells on laminin. There was also a decrease in angiogenesis as shown by the vascular endothelial growth factor staining. This was more pronounced by coating of the tissue culture plastic with matrix molecules. Our results supported the anti-cancer effect of 17-allylamino-17-demethoxygeldanamycin, and this effect depended on matrix molecules. This effect occurs through apoptosis, and related genes were also altered. All these genes may serve for novel target under the effect of matrix substrate. However, correct interpretation of the results requires further studies.

Cucurbitacins from the Leaves of Citrullus colocynthis (L.) Schrad

Two new tetracyclic cucurbitane-type triterpene glycosides were isolated from an ethyl acetate extract of Citrullus colocynthis leaves together with four known cucurbitacins. Their structures were established on the basis of their spectroscopic data (mainly NMR and mass spectrometry). Evaluation of the in vitro cytotoxic activity of the isolated compounds against two human colon cancer cell lines (HT29 and Caco-2) and one normal rat intestine epithelial cell line (IEC6), revealed that one of the isolated compounds presented interesting specific cytotoxic activity towards colorectal cell lines.