HS-116, a novel phosphatidylinositol 3-kinase inhibitor induces apoptosis and suppresses angiogenesis of hepatocellular carcinoma through inhibition of the PI3K/AKT/mTOR pathway

The expression of tuftelin 1 as a new theranostic marker in early diagnosis and as a therapeutic target in hepatocellular carcinoma

Currently, many challenges are associated with hepatocellular carcinoma (HCC) as the failure of early diagnosis, and the lack of effective therapy. This study aimed to investigate the possible role of tuftelin 1 (TUFT 1) in the early diagnosis of HCC and evaluate the potential contribution of the TUFT 1/Ca+2 /phosphinositol 3 kinase (PI3K) pathway in dantrolene sodium (Dan) therapeutic outcomes. The study was performed on two sets of rats, the staging (30 rats) and treatment sets (80 rats). HCC was induced by a single dose of diethylnitrosamine (DENA). The hepatic content of TUFT 1 protein was assayed via western blot and immunohistochemistry (IHC), while PI3K, vascular endothelial growth factor (VEGF), Cyclin D1, and matrix-metalloproteinase-9 (MMP-9) contents were assessed using enzyme-linked immunosorbent assay. Hepatic and serum calcium were measured colorimetrically. Furthermore, the nuclear proliferation marker, (Ki-67), (Kiel [Ki] where the antibody was produced in the University Department of Pathology and the original clone number is 67)-expression was assessed by IHC. TUFT 1/Ca+2 /PI3K signaling pathway was progressively activated in the 3 studied stages of HCC with subsequent upregulation of angiogenesis, cell cycle, and metastasis. More interestingly, Dan led to TUFT 1/Ca+2 /PI3K pathway disruption by diminution of the hepatic contents of TUFT 1, calcium, PI3K, VEGF, Cyclin D1, and MMP-9 in a dose-dependent pattern. TUFT 1 can serve as a theranostic biomarker in HCC. Moreover, Dan exerted an antineoplastic effect against HCC via the interruption of TUFT 1/Ca+2 /PI3K pathway.

ZLDI-8 suppresses angiogenesis and vasculogenic mimicry in drug-resistant NSCLC in vitro and in vivo

AIMS

The chemotherapy drugs for NSCLC often face the consequences of treatment failure due to acquired drug resistance. Tumor chemotherapy resistance is often accompanied by angiogenesis. Here, we aimed to investigate the effect and underlying mechanisms of ADAM-17 inhibitor ZLDI-8 we found before on angiogenesis and vasculogenic mimicry(VM) in drug-resistant NSCLC.

MAIN METHODS

The tube formation assay was used to evaluate angiogenesis and VM. Migration and invasion were assessed with transwell assays in the co-culture condition. To explore the underlying mechanisms of how ZLDI-8 inhibited tubes formation, ELISA assay and western blot assay were preformed. The effects of ZLDI-8 on angiogenesis in vivo were investigated in Matrigel plug, CAM and Rat aortic ring assays.

KEY FINDINGS

In the present study, ZLDI-8 significantly inhibited the tube formation of human umbilical vein endothelial cells (HUVECs) in either normal medium or in tumor supernatants. Furthermore, ZLDI-8 also inhibited VM tubes formation of A549/Taxol cells. In the co-culture assay, the interaction between lung cancer cells and HUVECs promotes increased cell migration and invasion, while ZLDI-8 eliminates this promotion. Moreover, the VEGF secretion were decreased by ZLDI-8 and the expression of Notch1, Dll4, HIF1α and VEGF were inhibited by ZLDI-8. In addition, ZLDI-8 can inhibit blood vessel formation in the Matrigel plug, CAM and Rat aortic ring assays.

SIGNIFICANCE

ZLDI-8 inhibits angiogenesis and VM in drug-resistant NSCLC through suppressing Notch1-HIF1α-VEGF signaling pathway. This study lays the foundation for the discovery of drugs that inhibit angiogenesis and VM in drug resistant NSCLC.

Biological impact and therapeutic perspective of targeting PI3K/Akt signaling in hepatocellular carcinoma: Promises and Challenges

Cancer progression results from activation of various signaling networks. Among these, PI3K/Akt signaling contributes to proliferation, invasion, and inhibition of apoptosis. Hepatocellular carcinoma (HCC) is a primary liver cancer with high incidence rate, especially in regions with high prevalence of viral hepatitis infection. Autoimmune disorders, diabetes mellitus, obesity, alcohol consumption, and inflammation can also lead to initiation and development of HCC. The treatment of HCC depends on the identification of oncogenic factors that lead tumor cells to develop resistance to therapy. The present review article focuses on the role of PI3K/Akt signaling in HCC progression. Activation of PI3K/Akt signaling promotes glucose uptake, favors glycolysis and increases tumor cell proliferation. It inhibits both apoptosis and autophagy while promoting HCC cell survival. PI3K/Akt stimulates epithelial-to-mesenchymal transition (EMT) and increases matrix-metalloproteinase (MMP) expression during HCC metastasis. In addition to increasing colony formation capacity and facilitating the spread of tumor cells, PI3K/Akt signaling stimulates angiogenesis. Therefore, silencing PI3K/Akt signaling prevents aggressive HCC cell behavior. Activation of PI3K/Akt signaling can confer drug resistance, particularly to sorafenib, and decreases the radio-sensitivity of HCC cells. Anti-cancer agents, like phytochemicals and small molecules can suppress PI3K/Akt signaling by limiting HCC progression. Being upregulated in tumor tissues and clinical samples, PI3K/Akt can also be used as a biomarker to predict patients' response to therapy.

ZDQ-0620, a Novel Phosphatidylinositol 3-Kinase Inhibitor, Inhibits Colorectal Carcinoma Cell Proliferation and Suppresses Angiogenesis by Attenuating PI3K/AKT/mTOR Pathway

The PI3K/AKT pathway plays a central role in human cancers, aberrant activation of this pathway is associated with tumorigenesis, cancer progression and angiogenesis. Based on the importance of the PI3K/AKT pathway in malignancies, we developed a 4-aminoquinazoline derivative, ZDQ-0620, initially envisioned as a novel pan-PI3K inhibitor. This study aimed to evaluate the potential target of ZDQ-0620 and its anticancer effect in human colorectal carcinoma (CRC). PI3K-kinase activity test showed IC50 of ZDQ-0620 against PI3Ka was 0.5 nM; molecular docking, CETSA assay and western blotting was further performed to predict ZDQ-0620 was a PI3K/AKT pathway inhibitor by targeting PI3K. To identify the effect of ZDQ-0620 on CRC cells, Sulforhodamine B (SRB) assay, flow cytometry, and Cell morphology analysis were conducted. The results showed that ZDQ-0620 inhibited the proliferation, migration and invasion of CRC cells, induced apoptosis through G0/G1 cell cycle arrest and mitochondrial pathway. Additionally, ZDQ-0620 inhibited the migration and tube formation of human umbilical vein endothelial cells (HUVECs). In vivo, neovascularization of rat aortic ring and chick chorioallantoic membrane (CAM) induced by VEGF was diminished when treated with ZDQ-0620. These results indicate that ZDQ-0620 induce apoptosis and anti-angiogenesis via inhibits the PI3K/AKT pathway. We suggest that the great potential of ZDQ-0620 as an effective treatment candidate against CRC.

Exosome-derived SNHG16 sponging miR-4500 activates HUVEC angiogenesis by targeting GALNT1 via PI3K/Akt/mTOR pathway in hepatocellular carcinoma

Accumulating evidence suggests cancer-derived exosomes play an important role in promoting angiogenesis. Long noncoding RNA small nucleolar RNA host gene 16 (SNHG16) is known to aggravate hepatocellular carcinoma (HCC) progression. However, the function of exosomal SNHG16 in HCC angiogenesis remains unclear. In this study, the expression of SNHG16 was significantly upregulated in HCC tissues and cell lines. The proliferative, migratory, and angiogenic abilities of HUVECs were enhanced after exposure to exosomes derived from HCC cells by transmitting SNHG16. In addition, SNHG16 was validated to promote the biological function of HUVECs directly. Exosomal SNHG16 increased GALNT1 expression to promote angiogenesis via sponging miR-4500. SNHG16/miR-4500/GALNT1 axis played an important role in exosome-mediated angiogenesis and tumor growth in vitro and vivo. Furthermore, SNHG16 activated PI3K/Akt/mTOR pathway via competing endogenous miR-4500 and GALNT1. Meanwhile, the expression of plasma exosomal SNHG16 upregulated in the plasma of HCC patients. These data elucidated the essential role of exosomal SNHG16 in communication between HCC cells and endothelial cells. Exosomal SNHG16 could be utilized as a therapeutic target for anti-angiogenesis in HCC progression.

Brassinin Inhibits Proliferation in Human Liver Cancer Cells via Mitochondrial Dysfunction

Brassinin is a phytochemical derived from Chinese cabbage, a cruciferous vegetable. Brassinin has shown anticancer effects on prostate and colon cancer cells, among others. However, its mechanisms and effects on hepatocellular carcinoma (HCC) have not been elucidated yet. Our results confirmed that brassinin exerted antiproliferative effects by reducing proliferating cell nuclear antigen (PCNA) activity, a proliferation indicator and inducing cell cycle arrest in human HCC (Huh7 and Hep3B) cells. Brassinin also increased mitochondrial Ca²⁺ levels and depolarized the mitochondrial membrane in both Huh7 and Hep3B cells. Moreover, brassinin generated high amounts of reactive oxygen species (ROS) in both cell lines. The ROS scavenger N-acetyl-L-cysteine (NAC) inhibited this brassinin-induced ROS production. Brassinin also regulated the AKT and mitogen-activated protein kinases (MAPK) signaling pathways in Huh7 and Hep3B cells. Furthermore, co-administering brassinin and pharmacological inhibitors for JNK, ERK1/2 and P38 decreased cell proliferation in both HCC cell lines more than the pharmacological inhibitors alone. Collectively, our results demonstrated that brassinin exerts antiproliferative effects via mitochondrial dysfunction and MAPK pathway regulation on HCC cells.

The importance of indole and azaindole scaffold in the development of antitumor agents

With some indoles and azaindoles being successfully developed as anticancer drugs, the design and synthesis of indole and azaindole derivatives with remarkable antitumor activity has received increasing attention and significant progress has been made. This paper reviews the recent progress in the study of tumorigenesis, mechanism of actions and structure activity relationships about anticancer indole and azindole derivatives. Combining structure activity relationships and molecular targets-related knowledge, this review will help researchers design more effective, safe and cost-effective anticancer indoles and azindoles agents.

Angiotensin II induces apoptosis of cardiac microvascular endothelial cells via regulating PTP1B/PI3K/Akt pathway

Endothelial cell apoptosis and renin-angiotensin-aldosterone system (RAAS) activation are the major pathological mechanisms for cardiovascular disease and heart failure; however, the interaction and mechanism between them remain unclear. Investigating the role of PTP1B in angiotensin II (Ang II)-induced apoptosis of primary cardiac microvascular endothelial cells (CMECs) may provide direct evidence of the link between endothelial cell apoptosis and RAAS. Isolated rat CMECs were treated with different concentrations of Ang II to induce apoptosis, and an Ang II concentration of 4 nM was selected as the effective dose for the subsequent studies. The CMECs were cultured for 48 h with or without Ang II (4 nM) in the absence or presence of the PTP1B inhibitor TCS 401 (8 μM) and the PI3K inhibitor LY294002 (10 μM). The level of CMEC apoptosis was assessed by TUNEL staining and caspase-3 activity. The protein expressions of PTP1B, PI3K, Akt, p-Akt, Bcl-2, Bax, caspase-3, and cleaved caspase-3 were determined by Western blot (WB). The results showed that Ang II increased apoptosis of CMECs, upregulated PTP1B expression, and inhibited the PI3K/Akt pathway. Furthermore, cotreatment with PTP1B inhibitor significantly decreased the number of apoptotic CMECs induced by Ang II, along with increased PI3K expression, phosphorylation of Akt and the ratio of Bcl-2/Bax, decreased caspase-3 activity, and a cleaved caspase-3/caspase-3 ratio, while treatment with LY294002 partly inhibited the anti-apoptotic effect of the PTP1B inhibitor. Ang II induces apoptosis of primary rat CMECs via regulating the PTP1B/PI3K/Akt pathway.

Long noncoding RNA HAGLROS promotes cell proliferation, inhibits apoptosis and enhances autophagy via regulating miR-5095/ATG12 axis in hepatocellular carcinoma cells

In this research, we planned to dig the possible influences and mechanism of long noncoding (lnc) RNA HAGLROS in the development and progression of hepatocellular carcinoma (HCC). The levels of lncRNA HAGLROS in HCC tumor samples and their relationship with clinicopathological characteristics and prognosis of patients with HCC were studied. Subsequently, overexpression and silenced approaches were used in HCC cells for detecting the effects of lncRNA HAGLROS on cell viability, apoptosis, and autophagy. Furthermore, we investigated whether HAGLROS could function as a competing endogenous RNA (ceRNA) to regulate miR-5095 expression in HCC cells, and explored the correlation between miR-5095 and ATG12. Besides, the correlation of HAGLROS, the consequent PI3K/AKT/mTOR signaling pathway was further explored. The level of HAGLROS was higher in HCC tissues and correlated with clinical performances including tumor stages or tumor differentiation. In contrast to the lower level, a higher level of HAGLROS correlated with a shorter survival time of patients with HCC. The suppression of HAGLROS decreased cell viability, promoted apoptosis, and inhibited autophagy. Moreover, HAGLROS negatively regulated miR-5095 expression, which further regulated HCC cell viability, apoptosis, and autophagy. In addition, ATG12 was targeted by miR-5095 and was then involved in miR-5095-regulated HCC cell biological processes including viability, apoptosis, and autophagy. Furthermore, overexpression of HAGLROS activated PI3K/AKT/mTOR signals. Our results revealed that HAGLROS is highly expressed in HCC, and its high level may correlate with the progression and development of HCC involving the processes of cell viability, apoptosis, and autophagy through the miR-5095/ATG12 axis and PI3K/AKT/mTOR signals.

Targeting the mTOR regulatory network in hepatocellular carcinoma: Are we making headway?

The mechanistic target of rapamycin (mTOR) pathway coordinates organismal growth and homeostasis in response to growth factors, nutrients, and cellular energy stage. The pathway regulates several major cellular processes and is implicated in various pathological conditions, including hepatocellular carcinoma (HCC). This review summarizes recent advances of the mTOR pathway, highlights the potential of the mTOR pathway as a therapeutic target, and explores clinical trials targeting the mTOR pathway in HCC. Although the review focuses on the mTOR pathway involved in HCC, more comprehensive discussions (eg, developing a rational design for future trials targeting the mTOR pathway) are also applicable to other tumors.

Protective effect of microRNA-224 on acute lower extremity ischemia through activation of the mTOR signaling pathway via CHOP in mice

Acute lower extremity ischemia (ALEXI) is known worldwide as an urgent condition, occurring when there is an abrupt interruption in blood flow into an extremity. This study aims to investigate whether microRNA-224 (miR-224) affects the ALEXI mice and the underlying mechanism. The miR-224 expression and C/EBP homologous protein (CHOP), mammalian target of rapamycin (mTOR), translation initiation factor 4E-binding protein 1 (4E-BP1), and phosphoprotein 70 ribosomal protein S6 kinase (p70S6K) messenger RNA (mRNA), as well as protein expressions, were determined. The target gene of miR-224 was also verified by using a luciferase reporter gene assay. The vascular endothelial cells from the ALEXI mice were transfected with miR-224 mimics, miR-224 inhibitors, or small-interfering RNA against CHOP. Cell proliferation was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cell cycle distribution along with the cell apoptosis were both evaluated by using a flow cytometry. The muscle fibers of the lower extremities found in the ALEXI mice were evidently swollen and rounded, presenting with a remarkably narrowed gap. The positive CHOP expression increased in ALEXI mice than normal mice, while the miR-224 expression and mTOR, 4E-BP1, and p70S6K mRNA, as well as the protein expression, decreased. Luciferase reporter gene assay validated that the miR-224 gene directly targeted CHOP. MiR-224 facilitated cell proliferation but inhibited cell apoptosis; by contrast, CHOP increased cell apoptosis. Moreover, the cells transfected along with miR-224 mimic exhibited a lower CHOP expression as well as increased mTOR, 4E-BP1, and p70S6K expression. Our study provided evidence that miR-224 could alleviate the occurrence and development of ALEXI in mice through activation of the mTOR signaling pathway by downregulating CHOP.

DCZ3301, a novel aryl-guanidino inhibitor, induces cell apoptosis and cell cycle arrest via suppressing the PI3K/AKT pathway in T-cell leukemia/lymphoma

DCZ3301, a novel aryl-guanidino compound, was previously found to have potent anti-tumor activity in myeloma and B-cell lymphoma. In the present study, we investigated the effects of DCZ3301 on T-cell leukemia/lymphoma cells both in vitro and in vivo via cell proliferation, cell cycle analysis, apoptosis assay, mitochondrial membrane potential (MMP) assay, western blot analysis and tumor xenograft models. We found that DCZ3301 inhibited the viability of T-cell leukemia/lymphoma cells in a dose- and time-dependent manner. DCZ3301-induced G2/M cell cycle arrest, associated with downregulation of CDK1, cyclin B1, and cdc25C. DCZ3301 also induced cell apoptosis by decreasing MMP in T-cell leukemia/lymphoma cells, but had no significant pro-apoptotic effect on normal peripheral blood mononuclear cells (PBMCs). In addition, DCZ3301-induced apoptosis may be mediated by the caspase-dependent pathway and suppressing the phosphoinositide 3-kinase (PI3K)/AKT pathway. Finally, we showed that DCZ3301 treatment effectively inhibited tumor growth, with no significant side effects, in xenograft mouse models. In conclusion, these results suggest that DCZ3301 may be regarded as a new therapeutic strategy for T-cell leukemia/lymphoma patients.

Luteoloside Inhibits Proliferation and Promotes Intrinsic and Extrinsic Pathway-Mediated Apoptosis Involving MAPK and mTOR Signaling Pathways in Human Cervical Cancer Cells

Cervical cancer is a common gynecological malignancy with high incidence and mortality. Drugs commonly used in chemotherapy are often accompanied by strong side-effects. To find an anti-cervical cancer drug with high effects and low toxicity, luteoloside was used to treat the cervical cancer cell line Hela to investigate its effects on cell morphology, proliferation, apoptosis, and related proteins. The study demonstrated that luteoloside could inhibit proliferation remarkably; promote apoptosis and cytochrome C release; decrease the mitochondrial membrane potential and reactive oxygen species level; upregulate the expression of Fas, Bax, p53, phospho-p38, phospho-JNK, and cleaved PARP; downregulate the expression of Bcl-2 and phospho-mTOR; activate caspase-3 and caspase-8; change the nuclear morphology, and fragmentate DNA in Hela cells. These results strongly suggest that luteoloside can significantly inhibit the proliferation and trigger apoptosis in Hela cells. In contrast, luteoloside had less proliferation inhibiting effects on the normal cell lines HUVEC12 and LO2, and minor apoptosis promoting effects on HUVEC12 cells. Furthermore, the luteoloside-induced apoptosis in Hela cells is mediated by both intrinsic and extrinsic pathways and the effects of luteoloside may be regulated by the mitogen-activated protein kinases and mTOR signaling pathways via p53.

Artemisia Capillaris leaves inhibit cell proliferation and induce apoptosis in hepatocellular carcinoma

BACKGROUND

Natural product is one of the most important sources of drugs used in pharmaceutical therapeutics. Artemisia capillaris has been traditionally used as a hepatoprotective and anti-inflammatory agent. In this study, we extracted an ethanol fraction (LAC117) from the dried leaves of Artemisia capillaris and identified its anticancer activity and mechanism of action against hepatocellular carcinoma (HCC).

METHODS

Anti-proliferative effect of LAC117 was evaluated by MTT assay and BrdU assay. The apoptotic effect of LAC117 on the expression of cleaved PARP and cleaved caspase-3 was evaluated by Western blot and immunohistochemistry from in vivo mouse xenograft, respectively.

RESULTS

We found that LAC117 strongly suppressed the growth and proliferation of human HCC cell lines (HepG2 and Huh7). Induction of apoptosis was evidenced by the increases of cleaved caspase-3 and PARP as well as TUNEL-positive cells. Additionally, the pro-apoptotic effect of LAC117 was observed by a decrease in the expression of the XIAP and an increase in cytochrome c releases via mitochondrial membrane potential. Moreover, it significantly inhibited PI3K/AKT pathway in HCC in vivo and in vitro. LAC117 suppressed tumor growth in an ex vivo model as well as in vivo mouse xenograft by inducing apoptosis and inhibiting tumor cell proliferation.

CONCLUSIONS

The present study highlights that LAC117 could not only efficiently induce apoptosis, but also inhibit the growth of human HCC cells by blocking the PI3K/AKT signaling pathway, suggesting that LAC117 would be a potentially useful drug candidate against HCC.

Expression of the β3 subunit of Na+/K+-ATPase is increased in gastric cancer and regulates gastric cancer cell progression and prognosis via the PI3/AKT pathway

ATP1B3 encodes the β3 subunit of Na⁺/K⁺-ATPase and is located in the q22-23 region of chromosome 3. Na⁺/K⁺-ATPase participates in normal cellular activities but also plays a crucial role in carcinogenesis. In the present study, we found that expression of the β3 subunit of Na⁺/K⁺-ATPase was increased in human gastric cancer tissues compared with that in normal matched tissues and that this increased expression predicted a poor outcome. ATP1B3 expression was elevated at both the mRNA and protein levels in gastric cancer cell lines relative to those in a normal gastric epithelial cell line. Interestingly, ATP1B3 knockdown significantly inhibited cell proliferation, colony-formation ability, migration, and invasion and increased apoptosis in human gastric carcinoma cell lines. Additionally, knockdown induced cell cycle arrest at the G2/M phase. Furthermore, we demonstrated that ATP1B3 silencing decreased the expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT) and phosphorylated AKT (p-AKT), indicating that ATP1B3 regulates gastric cancer cell progression via the PI3K/AKT signalling pathway. Hence, the β3 subunit of Na⁺/K⁺-ATPase plays an essential role in the tumourigenesis of gastric cancer and may be a potential prognostic and therapeutic target for the treatment of gastric cancer.

Shikonin suppresses proliferation and induces cell cycle arrest through the inhibition of hypoxia-inducible factor-1α signaling

Hypoxia enhances the development of solid tumors. Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor that is dominantly expressed under hypoxia in solid tumor cells and is a key factor of tumor regulation. HIF-1α regulates several target genes involved in many aspects of cancer progression, including angiogenesis, metastasis, and cell proliferation, as well as imparting resistance to cancer treatment. In this study, we assessed shikonin, which derives from the traditional medical herb Lithospermum erythrorhizon, for its anti-cancer effects in hypoxia-induced human colon cancer cell lines. Shikonin showed potent inhibitory activity against hypoxia-induced HIF-1α activation in various human cancer cell lines and efficient scavenging activity of hypoxia-induced reactive oxygen species in tumor cells. Further analysis revealed that shikonin inhibited HIF-1α protein synthesis without affecting the expression of HIF-1α mRNA or degrading HIF-1α protein. It was subsequently shown to attenuate the activation of downstream mTOR/p70S6K/4E-BP1/eIF4E kinase. Shikonin also dose-dependently caused the cell cycle arrest of activated HCT116 cells and inhibited the proliferation of HCT116 and SW620 cells. Moreover, it significantly inhibited tumor growth in a xenograft modal. These findings suggest that shikonin could be considered for use as a potential drug in human colon cancer therapy.

Anti-tumor effect of evodiamine by inducing Akt-mediated apoptosis in hepatocellular carcinoma

BACKGROUND

Evodiamine is an alkaloid extracted from Euodia rutaecarpa (Juss.) Benth. There is little information about the mechanisms of evodiamine on the apoptosis of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

A xenograft model and CCK8 assay were used to investigate the anti-HCC effect of evodiamine. The effect of evodiamine on apoptosis was evaluated by DAPI staining and flow cytometry. Western blot analyses and immunohistochemistry were processed to assess the protein expressions of Akt and apoptotic proteins.

RESULTS

Evodiamine suppressed tumor growth, improved the expression of cleaved-caspase3 and decreased tumor specific growth factor (TSGF) and alpha fetoprotein (AFP) activities. Furthermore, evodiamine inhibited cell viability and induced cell cycle arrest. DAPI staining revealed nuclear condensation in evodiamine-treated groups. Meanwhile, evodiamine increased the number of apoptotic cells. Furthermore, evodiamine suppressed Akt and regulated apoptotic proteins in HepG2 cells. Evodiamine decreased p-Akt levels activated by SC79, which led to the increase of bax/bcl-2 and cleaved-caspase3.

CONCLUSIONS

Our findings suggested that evodiamine could exert anti-HCC effect through inducing Akt-mediated apoptosis. Evodiamine has the potential to be a therapeutic medicine for HCCs.

Induction of apoptosis and proliferation inhibition of hepatocellular carcinoma by 6-chloro-2-methoxy-N-(phenylmethyl)-9-acridinamine (BA): in vitro and vivo studies

BACKGROUND

6-Chloro-2-methoxy-N-(phenylmethyl)-9-acridinamine (BA), a novel sponge-derived compound, has been reported to elicit a cytotoxic effect by inhibiting cell proliferation.

METHODS

In this study, we investigated the anti-tumor effect of BA in human hepatocellular carcinoma (HCC) in vitro and in vivo using SMMC-7721 cells. The impact of BA on SMMC-7721 cells was determined by proliferation (clonogenicity and MTT), apoptosis (flow cytometry with annexin V-FITC labeling) and tumor cell migration (Transwell). Apoptosis-related molecules in the PI3K/AKT signaling pathway were examined via Western blotting. We also evaluated the effects of BA on tumor growth using a xenograft nude mouse model.

RESULTS

The data showed that BA induced dose-dependent cytotoxicity, anti-proliferation, anti-migration and apoptosis in SMMC-7721 cells, accompanied by activation of caspase-3 and a decreased level of caspase-9. Moreover, BA decreased PI3K and p-AKT levels, which indicated the cytotoxicity of BA through the PI3K/Akt pathway. Finally, we confirmed that BA inhibited tumor growth in an HCC xenograft mouse model.

CONCLUSIONS

We concluded that BA induced apoptosis and decreased PI3K and p-AKT expression in human HCC with no effect on the liver, kidney, spleen or lungs. These findings suggest that BA could provide a novel strategy for the treatment of HCC.

The novel dual PI3K/mTOR inhibitor NVP-BGT226 displays cytotoxic activity in both normoxic and hypoxic hepatocarcinoma cells

Hepatocellular carcinoma (HCC) is one of the most common lethal human malignancies worldwide and its advanced status is frequently resistant to conventional chemotherapeutic agents and radiation. We evaluated the cytotoxic effect of the orally bioavailable dual PI3K/mTOR inhibitor, NVP-BGT226, on a panel of HCC cell lines, since hyperactivated PI3K/Akt/mTOR signaling pathway could represent a biomolecular target for Small Inhibitor Molecules in this neoplasia. We analyzed the drug activity in both normoxia and hypoxia conditions, the latter playing often a relevant role in the induction of chemoresistance and angiogenesis.In normoxia NVP-BGT226 caused cell cycle arrest in the G0/G1 phase of the cell cycle, induced apoptosis and autophagy at low concentrations. Interestingly the drug inactivated p-Akt and p-S6 at < 10 nM concentration.In hypoxia NVP-BGT226 maintained its cytotoxic efficacy at the same concentration as documented by MTT assays and Western blot analysis. Moreover, the drug showed in hypoxia inhibitory properties against angiogenesis by lowering the expression of the transcription factor HIF-1α and of VEGF.Our results indicate that NVP-BGT226 has a potent cytotoxic effect on HCC cell lines also in hypoxia condition, thus emerging as a potential candidate for cancer treatment in HCC targeted therapy.

Novel Imidazopyridine Derivatives Possess Anti-Tumor Effect on Human Castration-Resistant Prostate Cancer Cells

Prostate cancer (PCa) is the second leading cause of cancer-related death afflicting United States males. Most treatments to-date for metastatic PCa include androgen-deprivation therapy and second-generation anti-androgens such as abiraterone acetate and enzalutamide. However, a majority of patients eventually develop resistance to these therapies and relapse into the lethal, castration-resistant form of PCa to which no adequate treatment option remains. Hence, there is an immediate need to develop effective therapeutic agents toward this patient population. Imidazopyridines have recently been shown to possess Akt kinase inhibitory activity; thus in this study, we investigated the inhibitory effect of novel imidazopyridine derivatives HIMP, M-MeI, OMP, and EtOP on different human castration-resistant PCa cells. Among these compounds, HIMP and M-MeI were found to possess selective dose- and time-dependent growth inhibition: they reduced castration-resistant PCa cell proliferation and spared benign prostate epithelial cells. Using LNCaP C-81 cells as the model system, these compounds also reduced colony formation as well as cell adhesion and migration, and M-MeI was the most potent in all studies. Further investigation revealed that while HIMP primarily inhibits PCa cell growth via suppression of PI3K/Akt signaling pathway, M-MeI can inhibit both PI3K/Akt and androgen receptor pathways and arrest cell growth in the G2 phase. Thus, our results indicate the novel compound M-MeI to be a promising candidate for castration-resistant PCa therapy, and future studies investigating the mechanism of imidazopyridine inhibition may aid to the development of effective anti-PCa agents.

Cbl participates in shikonin-induced apoptosis by negatively regulating phosphoinositide 3-kinase/protein kinase B signaling

Shikonin, a naturally occurring naphthoquinone, exhibits anti-tumorigenic activity. However, its precise mechanisms of action have remained elusive. In the present study, the involvement in the action of shikonin of the ubiquitin ligases Cbl-b and c-Cbl, which are negative regulators of phosphoinositide 3-kinase (PI3K) activation, was investigated. Shikonin was observed to reduce cell viability and induce apoptosis and G2/M phase arrest in lung cancer cells. In addition, shikonin increased the protein levels of B-cell lymphoma 2 (Bcl-2)-associated X and p53 and reduced those of Bcl-2. Additionally, shikonin inhibited PI3k/Akt activity and upregulated Cbl protein expression. In addition, a specific inhibitor of PI3K, LY294002, was observed to have a synergistic effect on the proliferation inhibition and apoptotic induction of A549 cells with shikonin. In conclusion, the results of the present study suggested that Cbl proteins promote shikonin-induced apoptosis by negatively regulating PI3K/Akt signaling in lung cancer cells.

The azaindole framework in the design of kinase inhibitors

This review article illustrates the growing use of azaindole derivatives as kinase inhibitors and their contribution to drug discovery and innovation. The different protein kinases which have served as targets and the known molecules which have emerged from medicinal chemistry and Fragment-Based Drug Discovery (FBDD) programs are presented. The various synthetic routes used to access these compounds and the chemical pathways leading to their synthesis are also discussed. An analysis of their mode of binding based on X-ray crystallography data gives structural insights for the design of more potent and selective inhibitors.

Bufalin attenuates the stage and metastatic potential of hepatocellular carcinoma in nude mice

Background

Advanced hepatocellular carcinoma (HCC) patients undergo significant tumor growth and metastasis. Here, we investigated bufalin for treating HCC, which exhibits anti-tumor activities in many tumor cell lines.

Method

In our experiment, HCCLM3-R cells were injected into nude mice to form subcutaneous human HCC tumors that were implanted into the liver to establish orthotopic transplantation tumor models. Bufalin was injected intraperitoneally at 1 or 1.5 mg/kg. LY294002 (100 mg/kg), a potent inhibitor of Akt which reduced the levels of pAkt in HCCLM3 cell lines, was injected intraperitoneally into one group thrice weekly. The control was injected with an equal volume of saline. Morphological alterations were evaluated in the liver and lung by stereomicroscopy, the apoptotic rate was measured by TUNEL staining, and expression of AKT/GSK3β/β-catenin/E-cadherin signaling pathway-related proteins was detected by immunohistochemistry (IHC) and western blot analysis.

Results

These results suggested that the sizes and qualities of orthotopic transplanted tumors as well as pulmonary metastasis decreased markedly at the highest bufalin dose compared with that in the control. Orthotopic transplanted tumor tissues were necrotic in bufalin-treated groups and the apoptotic cell number was markedly higher at the highest bufalin dose compared with that in the control. Certain changes of expression of AKT/GSK3β/β-catenin/E-cadherin signaling pathway-related proteins were in tumor tissues, which were related to the bufalin dose. Similar results were observed in the LY294002-treated group.

Conclusion

Based on the above, one can draw conclusions that bufalin has significant anti-tumor activities and reduces the metastatic potential in an orthotopic transplantation tumor model of human HCC. Inhibition of AKT/GSK3β/β-catenin/E-cadherin signaling pathways by bufalin may show therapeutic effects in advanced HCC patients.

Active form of AKT controls cell proliferation and response to apoptosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related mortality worldwide. Deregulation of the AKT signaling pathway has been found in HCC. However, the effect of AKT activation on the proliferation and apoptosis in HCC is not clear. Herein, expression of phosphorylated form of AKT (Ser 473) was investigated in HCC tumor (n=73), cirrhosis (n=17), normal liver (n=22) samples and in HCC cell lines (n=8). The results showed that expression of p-AKT was higher in tumor (53%) than in cirrhotic tissues (12%) while it was absent in normal liver (p<0.0001). p-AKT expression was also associated with number of tumor nodules and differentiation status (p<0.05). LY294002 induced cell cycle arrest at G0/G1 in SNU-449 and Mahlavu cells by decreasing expression of CDK2, CDK4, CycD1, CycD3, CycE, CycA and increasing expression of p21 and p27 as well; it also caused a decrease in the E2F1 transcriptional activity through declining phosphorylated Rb. LY294002 did not affect the basal level of apoptosis; however, it amplified cisplatin-induced apoptosis in SNU-449 cells. When the p-AKT level was decreased specifically after transfection with the DN-AKT plasmid, SNU-449 cells became more sensitive to cisplatin-induced apoptosis. HuH-7 cells with no basal p-AKT, were markedly affected by the treatment of doxorubicin. Thus, Akt signaling controls growth and chemical-induced apoptosis in HCC and p-AKT may be a potential target for therapeutic interventions in HCC patients.

Bufalin, a component in Chansu, inhibits proliferation and invasion of hepatocellular carcinoma cells

Background

Hepatocellular carcinoma (HCC) is a common and aggressive cancer, and the treatment options are limited for patients with advanced HCC. Bufalin, the major digoxin-like component of the traditional Chinese medicine Chansu, exhibits significant anti-tumor activities in many tumor cell lines. In the present study, we investigated the effect of bufalin on the inhibition of an AKT-related signaling pathway, and examined the relationship between regulatory proteins and anti-tumor effects in hepatoma cells.

Methods

Proliferation, wound healing, transwell-migration/invasion and adhesion assays were performed in HCCLM3 and HepG2 cell lines. The protein levels of pAKT, AKT, pGSK3β, GSK3β, pβ-catenin, β-catenin, E-cadherin, MMP-9, and MMP-2 were measured by western blot analysis. E-Cadherin and β-catenin expression levels were also evaluated by immunofluorescence.

Results

Bufalin inhibited hepatoma cell proliferation, migration, invasion and adhesion. In addition, treatment with bufalin significantly decreased the levels of pAKT, pGSK3β, MMP-9, and MMP-2, while increasing the levels of GSK3β and E-cadherin and suppressing the nuclear translocation of β-catenin.

Conclusions

Bufalin is a potential anti-HCC therapeutic candidate through its inhibition of the AKT/GSK3β/β-catenin/E-cadherin signaling pathway. Further studies with bufalin are warranted in patients with HCC, especially those with the disease at advanced stages.

Plant cyclopeptide RA-V kills human breast cancer cells by inducing mitochondria-mediated apoptosis through blocking PDK1-AKT interaction

In the present paper, we examined the effects of a natural cyclopeptide RA-V on human breast cancer cells and the underlying mechanisms. RA-V significantly inhibited the growth of human breast cancer MCF-7, MDA-MB-231 cells and murine breast cancer 4T1 cells. In addition, RA-V triggered mitochondrial apoptotic pathway which was indicated by the loss of mitochondrial membrane potential, the release of cytochrome c, and the activation of caspase cascade. Further study showed that RA-V dramatically inhibited phosphorylation of AKT and 3-phosphoinositide dependent protein kinase 1 (PDK1) in MCF-7 cells. Moreover, RA-V disrupted the interaction between PDK1 and AKT in MCF-7 cells. Furthermore, RA-V-induced apoptosis could be enhanced by phosphatidylinositol 3-kinase inhibitor or attenuated by over-expression of AKT in all the three kinds of breast cancer cells. Taken together, this study shows that RA-V, which can induce mitochondria-mediated apoptosis, exerts strong anti-tumor activity against human breast cancer. The underlying anti-cancer mechanism of RA-V is related to the blockage of the interaction between PDK1 and AKT.