Targeting Akt by SC66 triggers GSK-3β mediated apoptosis in colon cancer therapy

Multiple roles of baicalin and baicalein in the regulation of colorectal cancer

The prevalence of colorectal cancer is increasing worldwide, and despite advances in treatment, colorectal cancer (CRC) remains in the top three for mortality due to several issues, including drug resistance and low efficiency. There is increasing evidence that baicalin and baicalein, novel small molecule inhibitor extracts of the Chinese herb Scutellaria baicalensis, have better anti-colorectal cancer effects and are less likely to induce drug resistance in cancer cells. The present review article explains the anti-proliferative properties of baicalin and baicalein in the context of against CRC. Additionally, it explores the underlying mechanisms by which these compounds modulate diverse signaling pathways associated with apoptosis, cell proliferation, tumor angiogenesis, invasion, metastasis, and tumor microenvironment. Moreover, this review article highlights the inhibitory effect of colorectal inflammatory-cancer transformation and the near-term therapeutic strategy of using them as adjuvant agents in chemotherapy.

Role of m6A modification in regulating the PI3K/AKT signaling pathway in cancer

The phosphoinositide 3-kinase (PI3K)/AKT signaling pathway plays a crucial role in the pathogenesis of cancer. The dysregulation of this pathway has been linked to the development and initiation of various types of cancer. Recently, epigenetic modifications, particularly N6-methyladenosine (m6A), have been recognized as essential contributors to mRNA-related biological processes and translation. The abnormal expression of m6A modification enzymes has been associated with oncogenesis, tumor progression, and drug resistance. Here, we review the role of m6A modification in regulating the PI3K/AKT pathway in cancer and its implications in the development of novel strategies for cancer treatment.

Inhibition of autophagy can promote the apoptosis of bladder cancer cells induced by SC66 through the endoplasmic reticulum stress pathway

Bladder cancer is among the ten most prevalent cancer types worldwide, and its prognosis has not improved significantly in the past three decades because of cognitive limitations in the molecular mechanisms that drive the malignant progression of bladder cancer. Therefore, there is an urgent need to identify new therapeutic drugs or molecular targets to improve the prognosis of patients with bladder cancer. SC66, a novel allosteric inhibitor of AKT, has recently been reported to exert potent anticancer effects on various cancer cells. However, the mechanisms underlying its anticancer effects in bladder cancer remain largely unknown. Consequently, this study aimed to conduct a series of molecular and cellular biology experiments to verify the anticancer effect and potential mechanism of action of SC66 in bladder cancer in vitro. A xenograft tumor model was established to confirm its anticancer role in vivo. Our results showed that SC66 inhibited cell proliferation, triggered mitochondria-mediated apoptosis, and initiated autophagy in bladder cancer cells dose-dependently. In addition, our results suggested that SC66-caused apoptosis and autophagy were endoplasmic reticulum stress-dependent. Interestingly, the activation of autophagy can partially protect bladder cancer cells from apoptosis under endoplasmic reticulum stress induced by SC66 treatment. This study shows that SC66 exerts its anticancer impact on bladder cancer by inhibiting cell proliferation and inducing apoptosis. It also reveals that inhibiting autophagy can increase the cytotoxic effects of SC66 in bladder cancer. Overall, this is the first study on the anticancer effect of SC66 mediated by the endoplasmic reticulum stress pathway and the first report on the AKT-independent anticancer mechanism of SC66 in bladder cancer. Conclusively, exploring the relationship between apoptosis, autophagy, and endoplasmic reticulum stress induced by SC66 indicates that SC66 is a promising novel agent for patients with bladder cancer.

Gnetum montanum extract induces apoptosis by inhibiting the activation of AKT in SW480 human colon cancer cells

CONTEXT

Gnetum montanum Markgr. (Gnetaceae) is used to treat rheumatic arthralgia and bruises in the clinic.

OBJECTIVE

To exam the activity and mechanism of G. montanum extract (GME) against colon cancer cells SW480.

MATERIALS AND METHODS

The anti-proliferative activity of GME (0-120 μg/mL) on SW480 cells was determined using MTS assay at 24, 48, and 72 h. The in vitro activity of GME (0-120 μg/mL) on SW480 cells was investigated using flow cytometry and western blotting analysis. The in vivo activity of GME was evaluated using xenograft tumour model of zebrafish and nude mice. The chemical composition of GME was detected by using HPLC-MS/MS.

RESULTS

The IC₅₀ value SW480 cells viability by GME were 126.50, 78.25, and 50.77 μg/mL, respectively, for 24, 48, and 72 h. The experiments showed that apoptotic cells and G2/M phase cells increased from 20.81 to 61.53% (p < 0.01) and 25.76 to 34.93% with 120 μg/mL GME, respectively. GME also down-regulated the protein expression of P-AKT, P-GSK-3β, P-PDK1, P-c-Raf, caspase-3, and Bcl-2, and up-regulated the expression cleaved caspase-3, cleaved PARP, and Bax. In vivo study found that GME can significantly inhibit the growth and migration of SW480 cells in xenograft zebrafish. GME reduced the nude mice tumour weight to approximately 32.19% at 28 mg/kg/day and to 53.17% (p < 0.01) at 56 mg/kg/day. Forty-two compounds were identified from the GME.

DISCUSSION AND CONCLUSIONS

GME has a significant antitumor effect on colon cancer cells SW480, and it has the potential to be developed as an anticancer agent.

Collagen Remodeling along Cancer Progression Providing a Novel Opportunity for Cancer Diagnosis and Treatment

The extracellular matrix (ECM) is a significant factor in cancer progression. Collagens, as the main component of the ECM, are greatly remodeled alongside cancer development. More and more studies have confirmed that collagens changed from a barrier to providing assistance in cancer development. In this course, collagens cause remodeling alongside cancer progression, which in turn, promotes cancer development. The interaction between collagens and tumor cells is complex with biochemical and mechanical signals intervention through activating diverse signal pathways. As the mechanism gradually clears, it becomes a new target to find opportunities to diagnose and treat cancer. In this review, we investigated the process of collagen remodeling in cancer progression and discussed the interaction between collagens and cancer cells. Several typical effects associated with collagens were highlighted in the review, such as fibrillation in precancerous lesions, enhancing ECM stiffness, promoting angiogenesis, and guiding invasion. Then, the values of cancer diagnosis and prognosis were focused on. It is worth noting that several generated fragments in serum were reported to be able to be biomarkers for cancer diagnosis and prognosis, which is beneficial for clinic detection. At a glance, a variety of reported biomarkers were summarized. Many collagen-associated targets and drugs have been reported for cancer treatment in recent years. The new targets and related drugs were discussed in the review. The mass data were collected and classified by mechanism. Overall, the interaction of collagens and tumor cells is complicated, in which the mechanisms are not completely clear. A lot of collagen-associated biomarkers are excavated for cancer diagnosis. However, new therapeutic targets and related drugs are almost in clinical trials, with merely a few in clinical applications. So, more efforts are needed in collagens-associated studies and drug development for cancer research and treatment.

AKT inhibition sensitizes EVI1 expressing colon cancer cells to irinotecan therapy by regulating the Akt/mTOR axis

PURPOSE

Ecotropic viral integration site 1 (EVI1) is an oncogenic transcription factor that has been attributed to chemotherapy resistance in different cancers. As yet, however, its role in colon cancer drug resistance is not completely understood. Here, we set out to investigate the functional and therapeutic relevance of EVI1 in colon cancer drug resistance.

METHODS

The EVI1 gene was knocked down in colon cancer cells that were subsequently tested for susceptibility to irinotecan using in vitro assays and in vivo subcutaneous mouse colon cancer models. The effect of EVI1 knockdown on the AKT-mTOR signaling pathway was assessed using cell line models, immunohistochemistry and bioinformatics tools. The anti-proliferative activity of AKT inhibitor GSK690693 and its combination with irinotecan was tested in colon cancer cell line models (2D and 3D). Finally, the therapeutic efficacy of GSK690693 and its combination with irinotecan was evaluated in xenografted EVI1 expressing colon cancer mouse models.

RESULTS

We found that EVI1 knockdown decreased cancer stem cell-like properties and improved irinotecan responses in both cell line and subcutaneous mouse models. In addition, we found that EVI1 downregulation resulted in inhibition of AKT/mTOR signaling and RICTOR expression. Knocking down RICTOR expression increased the cytotoxic effects of irinotecan in EVI1 downregulated colon cancer cells. Co-treatment with irinotecan and ATP-competitive AKT inhibitor GSK690693 significantly reduced colon cancer cell survival and tumor progression rates.

CONCLUSION

Inhibition of the AKT signaling cascade by GSK690693 may serve as an alternative to improve the irinotecan response in EVI1-expressing colon cancer cells.

MIF/SCL3A2 depletion inhibits the proliferation and metastasis of colorectal cancer cells via the AKT/GSK-3β pathway and cell iron death

This study investigated the mechanisms of migration inhibitory factor (MIF) and solute carrier family 3 member 2 (SLC3A2) in colorectal cancer progression. The levels of MIF and SLC3A2 expression in cells were measured by RT-qPCR. SW480 and SW620 cells were transfected with sh-MIF and sh-SLC3A2, respectively. MIF, SLC3A2, GPX4, E-cadherin and N-cadherin expression were detected by immunofluorescence (IF). CCK8 and Transwell assays were performed to detect cell proliferation and migration. Co-immunoprecipitation (CoIP) was used to measure the binding activity of MIF and SLC3A2. Finally, a nude mouse tumorigenicity assay was used to confirm the functions of MIF and SLC3A2 in colorectal cancer. Results showed that the levels of MIF and SLC3A2 expression were up-regulated in colorectal cancer cells. Inhibition of MIF or SLC3A2 expression prevented cell proliferation, migration, epithelial-mesenchymal transition (EMT) and invasion. In addition, knockdown of MIF and SLC3A2 promoted iron death in SW480 and SW620 cells. CoIP results showed that MIF and SLC3A2 directly interact with each other. Knockdown of both MIF and SLC3A2 inhibited tumour growth and metastasis via the AKT/GSK-3β pathway in vivo. The Akt/GSK-3β pathway was found to participate in regulating MIF and SLC3A2 both in vivo and in vitro. MIF and SLC3A2 might be potential biomarkers for monitoring the treatment of colorectal cancer.

Targeting ERK induced cell death and p53/ROS-dependent protective autophagy in colorectal cancer

In recent years, many studies have shown that autophagy plays a vital role in the resistance of tumor chemotherapy. However, the interaction between autophagy and cell death has not yet been clarified. In this study, a new specific ERK inhibitor CC90003 was found to suppress colorectal cancer growth by inducing cell death both in vitro and in vivo. Studies have confirmed that higher concentrations of ROS leads to autophagy or cell death. In this research, the role of CC90003-induced ROS was verified. But after inhibiting ROS by two kinds of ROS inhibitors NAC and SFN, the autophagy induced by CC90003 decreased, while cell death strengthened. In parallel, protective autophagy was also induced, while in a p53-dependent manner. After silencing p53 or using the p53 inhibitor PFTα, the autophagy induced by CC90003 was weakened and the rate of cell death increases. Therefore, we confirmed that CC90003 could induce autophagy by activating ROS/p53. Furthermore, in the xenograft mouse model, the effect was obtained remarkably in the combinational treatment group of CC90003 plus CQ, comparing with that of the single treatment groups. In a word, our results demonstrated that targeting ERK leads to cell death and p53/ROS-dependent protective autophagy simultaneously in colorectal cancer, which offers new potential targets for clinical therapy.

SC66 inhibits the proliferation and induces apoptosis of human bladder cancer cells by targeting the AKT/β-catenin pathway

Bladder cancer (BC) is a major disease of the genitourinary tract, and chemotherapy is one of the main treatments commonly used at present. SC66 is a new type of allosteric AKT inhibitor that is reported to play an effective inhibitory role in the progression of many other types of tumours, but there is no reported research on its role in BC. In this study, we found that SC66 significantly inhibited the proliferation and EMT‐mediated migration and invasion of T24 and 5637 cells. In addition, experiments confirmed that SC66 achieved its antitumour effect by inducing cell apoptosis and affecting the cell cycle. Luciferase assays confirmed that SC66 exerted an antitumour effect through the AKT/β‐catenin signalling pathway, and this inhibitory effect was reversed after the addition of the β‐catenin signalling pathway activator, CHIR‐99021. In addition, animal studies have shown that, compared with the control group, the experimental group with SC66 intraperitoneal injection showed significantly reduced the tumour weight and volume in nude mice with T24 tumours and that SC66 combined with cisplatin achieved better inhibition on tumours. Western blot analysis and immunohistochemistry staining confirmed that SC66 inhibited the EMT process in vivo and induced apoptosis through the AKT/β‐catenin signalling pathway. In conclusion, our study demonstrated that SC66 exerts a significant antitumour effect through the AKT/β‐catenin signalling pathway, thereby providing a new potential treatment for BC.

Attacking the PI3K/Akt/mTOR signaling pathway for targeted therapeutic treatment in human cancer

Cancer is the second leading cause of human death globally. PI3K/Akt/mTOR signaling is one of the most frequently dysregulated signaling pathways observed in cancer patients that plays crucial roles in promoting tumor initiation, progression and therapy responses. This is largely due to that PI3K/Akt/mTOR signaling is indispensable for many cellular biological processes, including cell growth, metastasis, survival, metabolism, and others. As such, small molecule inhibitors targeting major kinase components of the PI3K/Akt/mTOR signaling pathway have drawn extensive attention and been developed and evaluated in preclinical models and clinical trials. Targeting a single kinase component within this signaling usually causes growth arrest rather than apoptosis associated with toxicity-induced adverse effects in patients. Combination therapies including PI3K/Akt/mTOR inhibitors show improved patient response and clinical outcome, albeit developed resistance has been reported. In this review, we focus on revealing the mechanisms leading to the hyperactivation of PI3K/Akt/mTOR signaling in cancer and summarizing efforts for developing PI3K/Akt/mTOR inhibitors as either mono-therapy or combination therapy in different cancer settings. We hope that this review will facilitate further understanding of the regulatory mechanisms governing dysregulation of PI3K/Akt/mTOR oncogenic signaling in cancer and provide insights into possible future directions for targeted therapeutic regimen for cancer treatment, by developing new agents, drug delivery systems, or combination regimen to target the PI3K/Akt/mTOR signaling pathway. This information will also provide effective patient stratification strategy to improve the patient response and clinical outcome for cancer patients with deregulated PI3K/Akt/mTOR signaling.

A Potential Role for Integrin-Linked Kinase in Colorectal Cancer Growth and Progression via Regulating Senescence and Immunity

Integrin-linked kinase (ILK) has been implicated as a molecular driver and mediator in both inflammation and tumorigenesis of the colon. ILK functions as an adaptor and mediator protein linking the extracellular matrix with downstream signaling pathways. ILK is broadly expressed in many human tissues and cells. It is also overexpressed in many cancers, including colorectal cancer (CRC). Inflammation, as evidenced by inflammatory bowel disease (IBD), is one of the highest risk factors for initiating CRC. This has led to the hypothesis that targeting ILK therapeutically could have potential in CRC, as it regulates different cellular processes associated with CRC development and progression as well as inflammation in the colon. A number of studies have indicated an ILK function in senescence, a cellular process that arrests the cell cycle while maintaining active metabolism and transcription. Senescent cells produce different secretions collectively known as the senescence-associated secretory phenotype (SASP). The SASP secretions influence infiltration of different immune cells, either positively for clearing senescent cells or negatively for promoting tumor growth, reflecting the dual role of senescence in cancer. However, a role for ILK in senescence and immunity in CRC remains to be determined. In this review, we discuss the possible role for ILK in senescence and immunity, paying particular attention to the relevance of ILK in CRC. We also examine how activating Toll-like receptors (TLRs) and their agonists in CRC could trigger immune responses against cancer, as a combination therapy with ILK inhibition.

Anticancer property of Hemp Bioactive Peptides in Hep3B liver cancer cells through Akt/GSK3β/β-catenin signaling pathway

Foodborne protein hydrolysates exhibit biological activity that may be therapeutic in a number of human disease settings. Hemp peptides (HP) generated by controlled hydrolysis of hemp proteins have a number of health benefits and are of pharmaceutical value. In the present study, we produce small molecular weight HP from hemp seed and investigate its anticancer properties in Hep3B human liver cancer cells. We demonstrate that HP treatment increased apoptosis, reduced cell viability, and reduced cell migration in Hep3B human liver cancer cells without affecting the normal liver cell line L02. We correlate these phenotypes with increased cellular ROS levels, upregulation of cleaved caspase 3 and Bad, and downregulation of antiapoptotic Bcl-2. HP treatment led to increased Akt and GSK-3β phosphorylation, with subsequent downregulation of β-catenin, suggesting β-catenin signaling modulation as a critical mechanism by which HP exhibits anticancer properties. Our findings suggest HP are of potential therapeutic interest for liver cancer treatment.

Central and peripheral emetic loci contribute to vomiting evoked by the Akt inhibitor MK-2206 in the least shrew model of emesis

Akt (protein kinase B) signaling is frequently activated in diverse cancers. Akt inhibitors such as perifosine and MK-2206 have been evaluated as potential cancer chemotherapeutics. Although both drugs are generally well tolerated, among their most common side-effects vomiting is a major concern. Here we investigated whether these Akt inhibitors evoke emesis in the least shrew model of vomiting. Indeed, both perifosine and MK-2206 induced vomiting with maximal efficacies of 90% at 50 mg/kg (i.p.) and 100% at 10 mg/kg (i.p.), respectively. MK-2206 (10 mg/kg, i.p.) increased c-Fos immunoreactivity both centrally in the shrew brainstem dorsal vagal complex (DVC) emetic nuclei, and peripherally in the jejunum. MK-2206 also evoked phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) in both the DVC emetic nuclei and the enteric nervous system in the jejunum. The ERK1/2 inhibitor U0126 suppressed MK-2206-induced emesis dose-dependently. We then evaluated the suppressive efficacy of diverse antiemetics against MK-2206-evoked vomiting including antagonists/inhibitors of the: L-type Ca²⁺ channel (nifedipine at 2.5 mg/kg, subcutaneously (s.c.)); glycogen synthase kinase 3 (GSK-3) (AR-A014418 at 10 mg/kg and SB216763 at 0.25 mg/kg, i.p.); 5-hydroxytryptamine 5-HT₃ receptor (palonosetron at 0.5 mg/kg, s.c.); substance P neurokinin NK₁ receptor (netupitant at 10 mg/kg, i.p.) and dopamine D_2/3 receptor (sulpride at 8 mg/kg, s.c.). All tested antagonists/blockers attenuated emetic parameters to varying degrees. In sum, this is the first study to demonstrate how pharmacological inhibition of Akt evokes vomiting via both central and peripheral mechanisms, a process which involves multiple emetic receptors.

Design and Synthesis of New Benzo[d]oxazole-Based Derivatives and Their Neuroprotective Effects on β-Amyloid-Induced PC12 Cells

A series of novel synthetic substituted benzo[d]oxazole-based derivatives (5a-5v) exerted neuroprotective effects on β-amyloid (Aβ)-induced PC12 cells as a potential approach for the treatment of Alzheimer's disease (AD). In vitro studies show that most of the synthesized compounds were potent in reducing the neurotoxicity of Aβ25-35-induced PC12 cells at 5 μg/mL. We found that compound 5c was non-neurotoxic at 30 μg/mL and significantly increased the viability of Aβ25-35-induced PC12 cells at 1.25, 2.5 and 5 μg/mL. Western blot analysis showed that compound 5c promoted the phosphorylation of Akt and glycogen synthase kinase (GSK-3β) and decreased the expression of nuclear factor-κB (NF-κB) in Aβ25-35-induced PC12 cells. In addition, our findings demonstrated that compound 5c protected PC12 cells from Aβ25-35-induced apoptosis and reduced the hyperphosphorylation of tau protein, and decreased the expression of receptor for AGE (RAGE), β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1), inducible nitric oxide synthase (iNOS) and Bcl-2-associated X protein/B-cell lymphoma 2 (Bax/Bcl-2) via Akt/GSK-3β/NF-κB signaling pathway. In vivo studies suggest that compound 5c shows less toxicity than donepezil in the heart and nervous system of zebrafish.

AKT Inhibitor SC66 Inhibits Proliferation and Induces Apoptosis in Human Glioblastoma Through Down-Regulating AKT/β-Catenin Pathway

Glioblastoma multiforme (GBM) is the most common intracranial malignancy in adults with the highest degree of malignancy and mortality. Due to its nature of diffuse invasiveness and high migration, GBM lacks an effective treatment strategy and is associated with poor prognosis. SC66 is a novel AKT inhibitor that has been reported to exert antiproliferative activity in many types of cancer cells. However, it remains unclear whether SC66 has antitumor effects in GBM. In this study, we found SC66 obviously suppressed U87 and U251 cell proliferation and EMT- mediated cell migration and invasion. Moreover, SC66 induced GBM cells apoptosis and arrested cell cycle in G0/G1 phase. Furthermore, SC66 also downregulated AKT signaling pathway in a concentration dependent manner. We also found the level of β-catenin nuclear translocation was prominently downregulated after SC66 treatment. Meanwhile, TCF/LEF luciferase report assay indicated that the activity of TCF/LEF was remarkably suppressed. Elevating β-catenin activity by using IM12 rescued SC66 inhibition-mediated GBM cell proliferation and metastasis. In addition, SC66 showed significantly suppressed the tumorigenicity compared to the control group in the xenograft mouse model. In conclusion, our study demonstrated that SC66 exerts prominently antitumor efficiency in GBM cells in vivo and in vitro by downregulated AKT/β-catenin pathway.

Cannabidiol attenuates methamphetamine-induced conditioned place preference via the Sigma1R/AKT/GSK-3β/CREB signaling pathway in rats

Methamphetamine (METH) is a highly addictive psychostimulant. Cannabidiol (CBD) is an exogenous cannabinoid without psychostimulating activity, which has potential therapeutic effects on opioid addiction. However, it is unclear whether CBD has therapeutic effects on METH-induced motivational effects. The present study examines whether CBD has a protective effect on METH-induced conditioned place preference (CPP) in rats by regulating the Sigma1R and AKT-GSK3β-CREB signaling pathway. Seventy rats were equally and randomly divided into seven groups. The rat CPP model was established via the intraperitoneal injection (IP) of 2 mg/kg of METH. Next, the intraperitoneal injection of 10, 20, 40, and 80 mg/kg CBD was performed 1 h prior to the injection of saline or METH. The protein expression levels of Sigma1R, AKT, p-AKT, GSK-3β, p-GSK-3β, CREB, and p-CREB in the rats' prefrontal cortex, nucleus accumbens, and hippocampus and ventral tegmental were detected using western blot analysis. CBD was found to inhibit METH-induced CPP in a dose-dependent fashion. The expression levels of Sigma1R, p-AKT, p-GSK3β, and p-CREB increased significantly in the METH-induced CPP model. Treatment involving different doses of CBD caused differential inhibitory responses in the cellular protein abundance of Sigma1R, p-AKT, p-GSK3β, and p-CREB across various brain regions. The present study found that METH can induce CPP in rats. When a pretreatment of CBD is applied, the CBD can weaken CPP in METH-induced rats by regulating the SigmaR1/AKT/GSK-3β/CREB signaling pathway. The results of this study indicate that CBD has a potential therapeutic effect on METH-induced rewarding effects.